Skip to content
naulon

No retraction, correction or concern found when last checked on Oct 22, 2026.

Challenges and opportunities for managing aquatic mercury pollution in altered landscapes

Heileen Hsu-Kim, Chris S. Eckley, Dario Achá and 4 more

Ambio · 2018 · CC BY

doi:10.1007/s13280-017-1006-7

Abstract

Electronic supplementary material. The online version of this article (10.1007/s13280-017-1006-7) contains supplementary material, which is available to authorized users.

Full text

From PubMed Central, U.S. National Library of Medicine, as current on Oct 22, 2026. Paragraph numbers are ours, so an answer can point at one.

Introduction

Global efforts sparked by the Minamata Convention are underway to reduce releases of mercury (Hg) to the environment (Selin et al. ). These efforts, in addition to global perturbations such as climate change, have the potential to greatly alter the worldwide distribution and impact of Hg, as described in companion papers (Eagles-Smith et al.; Obrist et al.; Selin et al. ). Hg exposure risk can be ameliorated by strategic management of individual ecosystems. In this paper we review and evaluate the many site-specific human activities and alterations to landscapes that can affect Hg transport, methylation, and bioaccumulation, including mining, forestry operations, urbanization, rice cultivation, nutrient loadings, wetland and reservoir creation and management, and industrial contamination.

While Hg released into the environment is typically in an inorganic form, concerns about human and wildlife exposure are mostly related to monomethylmercury (MeHg) that accumulates in fish and other food. MeHg is produced in ecosystems through naturally occurring processes that convert inorganic Hg to MeHg. These processes and the extent of MeHg bioaccumulation are key aspects of the Hg cycle and depend on a number of site-specific conditions. To illustrate the critical role of ecosystem processes in Hg exposure risk, Fig. 1 shows the broad range of MeHg levels found in the sediments and soils of more than 200 perturbed systems, spanning a wide range of Hg contamination. MeHg content as a fraction of total Hg spans three to four orders of magnitude at any given total Hg content.

To evaluate the impacts of natural and anthropogenic perturbations on Hg exposure risk, we must consider the complex array of atmospheric, hydrological, biological, ecological, and geochemical processes that control Hg transport and transformation to MeHg in the environment, as described in many previous reviews (Ullrich et al.; Selin; Liu et al.; Lucotte et al.; Driscoll et al.; Hsu-Kim et al. ) and highlighted briefly here. Atmospheric Hg is primarily in the gaseous elemental form Hg0, which has a relatively long atmospheric lifetime allowing for its widespread distribution (Schroeder and Munthe ). The oxidation of Hg0 in the atmosphere is a key process that governs the spatial distribution of wet and dry Hg deposition to land or water (Selin ). Deposited Hg can be highly reactive towards further transformation such as photochemical reduction (Amyot et al.; Schroeder and Munthe ), incorporation into vegetation (Graydon et al.; Rea et al. ), chelation to dissolved natural organic matter (NOM) (Aiken et al., ), and sorption to particles (e.g., organic matter, minerals, microorganisms) (Gerbig et al.; Liu et al.; Skyllberg; Vost et al. ). In addition to direct atmospheric deposition, Hg release into waterways can originate from upland runoff, industrial and mining point sources, and remobilization and resuspension of contaminated sediment and soil (Selin; Driscoll et al. ). Hg released to waterways is generally strongly chelated (e.g., Hg-NOM) or associated with particles (both particulate NOM and mineral particles) (Han and Gill; Hsu-Kim and Sedlak; Balogh et al.; Schuster et al.; Dittman et al. ). Thus, factors that influence NOM and particle mobilization are critical drivers of Hg transport.

Recently deposited, transported, or mineralized Hg tends to be more reactive towards methylation and bioaccumulation than “old” Hg that has aged in place in sediments and soil (Hintelmann et al.; Paterson et al.; Harris et al.; Orihel et al.; Jonsson et al., ). The aging effect for Hg may stem from the relative differences in bioavailability of Hg forms; weakly sorbed, amorphous, or nanostructured Hg forms may be more soluble at the bacterial cell envelope compared to more recalcitrant forms of Hg (e.g., strongly sorbed to particulate matter, sparingly soluble microcrystalline Hg mineral forms) (Fig. 2) (Deonarine and Hsu-Kim; Graham et al.; Jonsson et al.; Zhang et al.; Pham et al. ). Knowledge of the relative bioavailability of inorganic Hg species could allow site managers to develop strategies that distinguish exposure risks between multiple sources of Hg. However, we still lack tools that can quantitatively classify the sources of Hg with respect to methylation and food web accumulation potential. The challenge is due to the complexity of the Hg biogeochemical cycle in aquatic ecosystems as well as limitations of existing measurement capabilities.

The conversion of inorganic Hg to MeHg in the environment is primarily a microbially driven process that is commonly present in anaerobic sediments, saturated soils, anoxic bottom waters, as well as anoxic engineered systems (e.g., wastewater treatment, bioreactors) (Barkay and Wagner-Dobler ). There is also evidence of MeHg production in O2-containing surface oceans (Lehnherr et al.; Lamborg et al.; Gionfriddo et al. ), although the mechanisms of this process are not well understood. Hg-methylating microorganisms identified to date include sulfate reducers, iron reducers, methanogens, and a handful of fermentative and syntrophic Firmicutes (Compeau and Bartha; Fleming et al.; Kerin et al.; Ranchou-Peyruse et al.; Gilmour et al.; Yu et al.; Podar et al. ). The diversity of these organisms is still being realized; however, they all share the hgcA and hgcB gene cluster that encodes for proteins involved in intracellular methylation of inorganic Hg(II) (Parks et al. ). Methylating organisms are prevalent in benthic aquatic settings [e.g., saturated soil and sediment (Gilmour et al.; Branfireun et al.; King et al.,; Hines et al.; Monperrus et al.; Mitchell and Gilmour; Avramescu et al. )] as well other microenvironments with steep redox gradients (e.g., periphyton, biofilms, microbial flocs) (Mauro et al.; Achá et al.; Yu et al.; Hamelin et al.; Ortiz et al.; Podar et al.; Gascón Díez et al.; Olsen et al. ).

MeHg can also be degraded by biotic and abiotic processes. These include photochemical decomposition pathways (Sellers et al.; Hammerschmidt and Fitzgerald; Lehnherr and St. Louis; Hammerschmidt and Fitzgerald; Zhang and Hsu-Kim; Black et al. ) and the microbial Hg detoxification pathway encoded by the mer operon, which can both demethylate MeHg and reduce inorganic Hg(II) to Hg0 (Barkay and Wagner-Dobler ). The mer system is found mainly in aerobic bacteria and is believed to be inducible with sufficient Hg exposure to the organism. MeHg degradation in anaerobic niches can be rapid (Hines et al.; Tjerngren et al.; Cesário et al. ), but much less is known about microbial MeHg decomposition and dark abiotic demethylation processes (e.g., via sulfides) in anaerobic settings (Craig and Moreton; Oremland et al.; Wallschlager et al.; Jonsson et al. ).

While establishing the net production of MeHg in aquatic systems would be a major step towards understanding the potential risk of Hg pollution, the bioaccumulation and biomagnification of MeHg in the food web determines mercury exposure to humans and wildlife. The process of MeHg bioaccumulation depends on many ecological factors, though food web dynamics appears to be the primary driver of MeHg levels in fish and other wildlife, rather than microbial methylation of Hg in benthic environments (Eagles-Smith et al. ).

Overall, many factors influence Hg mobilization, transformation, and food web accumulation. While this complexity can be daunting for environmental managers and regulators to address, it also means that there are multiple approaches that could be pursued to reduce MeHg levels in biota. In the following text, we consider a variety of ecosystem-scale stresses and perturbations, their effects on Hg cycling in aquatic systems, and possible opportunities for policy and research to mitigate negative consequences.

Altered surface loadings

Controls on global atmospheric Hg emissions and subsequent reduction of Hg loadings to surface waters are expected to result in an eventual decrease of Hg bioaccumulation in fisheries. The timing of this response, however, has substantial uncertainty due to the legacy of stored Hg in terrestrial and sediment compartments of watersheds and the variability in Hg retention times among watersheds (Munthe et al. ). For example, Hg directly deposited to surface waters from the atmosphere has been observed to methylate and bioaccumulate in aquatic food webs relatively quickly (e.g., within months to a year), while Hg deposited to upland terrain generally requires much more time (a decade or more) for subsequent impact on pelagic food webs (Harris et al.; Oswald et al. ). Because of this time difference, the response of individual water bodies to increases or decreases in Hg loadings is expected to vary widely with the relative contributions of atmospheric and terrestrial Hg inputs (Fig. 3, Table S1). Direct atmospheric deposition of Hg tends to dominate over runoff inputs in marine water bodies. In contrast, lakes and estuaries tend to have greater terrestrial Hg inputs relative to atmospheric Hg deposition. This ratio depends on surface water area relative to watershed drainage area, the type of land cover within the drainage area (e.g., forested, urban, etc.), and the presence of known historical point sources of Hg.

While upland soils in watersheds are known to be long-term sources of total inorganic Hg to downstream surface waters, they can also be major sources of MeHg due to methylation of Hg and storage of MeHg in saturated soils (e.g., forest and wetland areas) (St. Louis et al.; Mitchell et al.,; Chen et al. ). Land use changes that impact flow paths, including forestry practices as described below, can exacerbate MeHg flux from watersheds (e.g., Shanley et al.; Flanders et al.; Babiarz et al. ). This increase in MeHg flux from upland soils directly to surface waters could provide a direct path towards bioaccumulation of MeHg in the pelagic food web, especially compared to other potential sources of MeHg such as sediments that would enter the water column at a slower rate (Jonsson et al. ). Terrestrial runoff of NOM can also change the base of the food web from autotrophic to heterotrophic production, resulting in a shift of the food web structure and subsequent MeHg bioaccumulation pathways (Jonsson et al. ).

The loading rates of other key constituents (e.g., organic carbon, sulfur, nitrogen, phosphorous) can also alter the biogeochemical cycle of Hg. For example, organic carbon loading to aquatic ecosystems impacts Hg cycling in a variety of ways. Dissolved and particulate NOM tends to be the vehicle of Hg transport in surface waters. Thus, increased organic carbon loads often result in increased Hg loads (Schuster et al.,; Brigham et al.; Scudder ). Organic matter production or release can contribute to eutrophication and increase the extent and duration of anoxic conditions in thermally stratified water bodies. These changes affect redox gradients which can result in increased MeHg production (Driscoll et al.; Slotton et al.; Watras et al.; Herrin et al.; Eckley and Hintelmann; Merritt and Amirbahman ). Chelation of inorganic Hg(II) by NOM has the potential to lower the bioavailability of Hg for methylation; however, this effect might be masked by stimulation of Hg methylators, depending on the type of NOM (Drott et al.; Kim et al.; Gascón Díez et al.; Mazrui et al.; Bravo et al. ) and the limiting factor for net Hg methylation (e.g., Hg speciation, productivity of methylators, or demethylation processes) (Jonsson et al.; Zhang et al.; Kucharzyk et al.; Liem-Nguyen et al. ). Organic matter loads also influence the structure of pelagic food webs, with secondary impacts on MeHg biomagnification (Jonsson et al. ). Taken together, these processes illustrate how organic carbon cycling in watersheds is intertwined with Hg cycling in complex and non-linear relationships.

The impact of sulfate loadings on Hg cycling is well documented. Sulfate originating from atmospheric deposition, upland runoff, and industrial sources can stimulate the activity of sulfate-reducing bacteria in peatlands and freshwater ecosystems, resulting in enhanced MeHg production rates (Gilmour et al.; Branfireun et al.; Jeremiason et al.; Mitchell et al.; Coleman Wasik et al.; Akerblom et al. ). Thus, reduction of sulfurous acid deposition has the potential to also reduce MeHg production and bioaccumulation (Hrabik and Watras; Watras and Morrison; Coleman Wasik et al. ). While this impact is straightforward, a secondary effect of elevated sulfate loading is enhanced microbial production of sulfide (e.g., Bailey et al. ). Inorganic sulfide in turn alters the distribution of dissolved and particulate Hg in benthic settings (Fig. 2), depending on the relative amounts of Hg, sulfide, and organic matter in the system. The development of models that can successfully discern the speciation of Hg (or even the bioavailable fraction) in environmental samples remains a major unmet need within research, management, and policy communities.

Increased loadings of nutrients (nitrogen and phosphorous) to lakes and coastal systems and subsequent eutrophication can alter Hg biogeochemistry in numerous ways. For example, eutrophication can lower the concentrations of MeHg in biota via biodilution and growth dilution, a process that lowers concentrations of MeHg in primary producers and consumers due to increased biomass (Pickhardt et al.; Chen and Folt; Pickhardt et al.; Kim et al.; Luengen and Flegal; Gosnell et al. ). In addition, eutrophication can alter organic carbon loads to surface waters, resulting in mixed effects that can increase or decrease MeHg levels in surface waters, as noted above. Managed alterations such as additions of nitrate or hypolimnetic oxygenation in the field have been attempted with some success to change redox conditions and decrease MeHg concentrations in water, but these manipulations do not always result in reductions of MeHg in biota (Matthews et al.; Austin et al.; Beutel et al.; McCord et al. ).

Due to the complex nature of the biogeochemical cycle of Hg, predicting the net effect of altered loadings of Hg, MeHg, organic carbon, nutrients, sulfate, and other constituents on MeHg accumulation in organisms remains a significant challenge. In this respect, management solutions that utilize a watershed loadings approach (such as total maximum daily loads in the U.S.) are difficult to formulate. While much remains to be learned, conceptual models could still be useful for understanding the main effects of altered surface loadings. For example, predictions on the impacts of eutrophication have been successful in some cases (e.g., wastewater nutrient inputs) but not others (e.g., estuarine nutrient export to coastal waters) (Driscoll et al. ). Regardless, these models highlight the relative importance of eutrophication, including biodilution, increased sedimentation of Hg, and the potential for increased in situ production of MeHg (Driscoll et al.; Soerensen et al. ). Likewise, identification of the chemical forms (or aging states) of Hg and MeHg that enter surface waters can help guide policies that prioritize reductions of certain sources, or perhaps assign value terms to individual sources as a basis for economic incentives or trading programs for discharge permits. These management approaches will require a richer understanding of uncertainties associated with the assignment of values, and in particular, methods to quantify Hg and MeHg bioavailability to relevant organisms.

Forestry and deforestation

Undisturbed forested ecosystems can effectively sequester Hg via accumulation in vegetation and soils (Obrist et al. ). As a result, forested ecosystems typically have relatively low runoff yields, averaging 6 ± 2 % of atmospheric Hg deposition (Mason et al.; Balogh et al.; Shanley et al.; Domagalski et al. ). In streams and rivers draining from harvested catchments, increases in total Hg and MeHg concentrations have been observed in many (but not all) studies and have been attributed to increased soil erosion, Hg methylation activity, and/or mobilization of near surface Hg pools in soils (Roulet et al.; Fostier et al.; Roulet et al.; Porvari et al.; Mainville et al.; Allan et al.; Sorensen et al.; Lacerda et al.; Eklof et al.,; de Wit et al.; Kronberg et al.; Ukonmaanaho et al. ). Soil erosion can occur as a result of vegetation removal, road construction, and/or other forest harvesting practices. In addition to erosion, the burning of forest slash following logging (as often occurs in tropical regions where forests are converted to agriculture) has been shown to increase Hg mobilization via inundation of the otherwise poor soils with cations (Farella et al.; Beliveau et al.; Comte et al. ).

Regardless of the impact of forestry operations on Hg concentrations, the fluxes of Hg from harvested catchments are typically two-fold higher than that from undisturbed forests, largely due to increases in stream discharge following logging (Porvari et al.; Allan et al.; Sorensen et al.; de Wit et al.; Eklof et al.; Kronberg et al. ) (Fig. 4). Discharge can increase due to reductions in evapotranspiration, interception, and infiltration as well as modified snow accumulation and melt rates. Forest harvesting can also increase MeHg production and/or mobilization through several mechanisms. For example, decreased evapotranspiration can lead to an elevated water table, increased soil moisture, and ponding, all of which foster anoxic conditions favorable for methylation (Munthe and Hultberg; Braaten and de Wit; Kronberg et al. ). Furthermore, fresh organic carbon inputs from logging debris left on the site may enhance microbial activity and MeHg production (Eklof et al.; Kronberg et al. ). However, increased MeHg concentrations in streamwater draining harvested watersheds have only been clearly observed in some studies (Porvari et al.; Skyllberg et al.; Eklof et al. ), whereas others have shown no significant change in MeHg response to forestry operations (Allan et al.; Eklof et al.; de Wit et al.; Kronberg et al. ). The differing responses among studies, for MeHg as well as total Hg, are most likely due to site-specific variations in harvesting practices (e.g., the degree of soil disturbance), catchment characteristics (e.g., water table depth, slope, hydrological flow paths), and meteorological differences (e.g., timing and amount of precipitation). As such, it remains difficult to make broad generalizations about the impacts of forestry operations on Hg cycling and MeHg production.

Greater solar radiative fluxes reach the soil in harvested catchments, leading to warmer temperatures, which facilitate photoreduction and evasion of soil-bound Hg (Mazur et al. ). In addition, deposition of gaseous Hg to vegetation can have a large impact on the net amount of Hg released from a landscape, and the reduction in plant uptake following forestry operations increases the net evasion of Hg to the atmosphere (Eckley et al. ). Releases of Hg from the surface following forest harvesting may be similar or larger in magnitude to losses via aqueous fluxes (Mazur et al.; Gamby et al.; Eckley et al. ). Despite increased releases to air and water, harvested catchments are still expected to be a net-sink for atmospheric Hg inputs, albeit less efficient ones compared to undisturbed forests (Fig. 4).

In addition to catchment-scale impacts, several studies in boreal and temperate forests have shown that logging activity correlates with increased Hg concentrations in sediment and aquatic biota in downstream waterbodies (Garcia and Carignan,; Sampaio Da Silva et al.; Desrosiers et al.; Van Furl et al. ). The degree to which forestry operations contribute to the variability of Hg concentrations in fish among lakes may be relatively minor compared to other factors such as physiography and climate, and the impact is less detectable in larger lakes (Lucotte et al. ). An understudied area is how the potential impacts of forest harvesting on other biogeochemical constituents, particularly nutrients, alters the overall ecology of downstream aquatic ecosystems. This knowledge gap obscures the impacts on Hg bioaccumulation in receiving waters through processes such as growth dilution and biodilution (as noted in the previous Sect. 2). Augmented NOM transport from watersheds as a function of harvesting, in addition to being a potential vector for Hg transport, may also impact photochemical transformations and thus the pools of inorganic Hg (O’Driscoll et al. ) and MeHg (Klapstein et al. ) in lake waters.

Harvesting and site preparation methods that minimize machinery damage of soils (e.g., winter harvesting on frozen ground) and promote rapid revegetation appear to result in little to no downstream MeHg impact (Sorensen et al. ), whereas practices such as stump harvesting, mounding, and scarification can lead to significant or highly variable impacts depending on site characteristics (Munthe and Hultberg; Eklof et al., ). Other forestry best management practices, such as the protection of streamside management zones and riparian buffers, generally offer improved water quality outcomes (Lakel et al. ), but there is a limited understanding of how these practices influence total Hg and MeHg cycling. Other common management practices, such as the use of well-designed, located, and maintained log landings, skid trails, and forest roads (Brown et al. ), have not been well studied in relation to the management of Hg mobility and contamination, but one could postulate that surface erosion control is a strategy that can decrease downstream Hg transport in nearly all instances.

In summary, the impact of forestry operations and deforestation on Hg is variable among catchments and forestry practices, but generally involves alterations to watershed loadings of Hg, organic carbon, and nutrients. Much research remains to be conducted in ecosystems outside of boreal forests of the northern latitudes, particularly in tropical regions. Regardless, relatively well-established best management practices involving careful site selection and protections against soil disturbance and erosion should help alleviate the magnitude and impacts of Hg transport and transformation.

Reservoir creation

The impoundment of rivers and streams and the subsequent creation of reservoirs are among the most common anthropogenic manipulations of freshwater aquatic ecosystems. Reservoirs typically aim to provide flood control or water supplies for irrigation and electricity utilities. Their impacts on Hg bioaccumulation have been closely studied in numerous locations. Globally, the total area impounded by dams may rival the total surface area of natural lakes (St. Louis et al. ) and continues to grow, particularly in tropical regions of the southern hemisphere (Shiklomanov and Rodda; Tuomola et al. ). The impacts of reservoir creation on Hg cycling typically result in an increase in MeHg production and can occur as part of shorter-term impacts following the construction of the reservoir as well as ongoing impacts due to hydrological, ecological and biogeochemical changes (Fig. 5).

For newly created reservoirs, the increase in MeHg production and bioaccumulation results from the decomposition of flooded terrestrial organic material, which leads to increased microbial activity and increased net MeHg production in flooded soils (Mucci et al.; Porvari and Verta; Kelly et al.; Hall and Louis; Hall et al.; St. Louis et al.; Hall et al. ). However, there are several studies from reservoirs in China where elevated fish Hg concentrations did not follow impoundment (Horvat et al.; He et al.; Feng et al.; Liu et al.; Li et al. ), likely due to low catchment organic matter content. Based on this observation, reductions in catchment organic matter prior to flooding have been proposed as a means to mitigate Hg impacts before reservoir creation (Mailman and Bodaly ).

Research over the last four decades has demonstrated that reservoirs can have elevated fish Hg concentrations compared to rivers and natural lakes (Meister et al.; Montgomery et al.; Brigham et al.; Kamman et al. ); however, the extent and timing of effects varies considerably. In large piscivorous fish in boreal Canadian reservoirs, Hg levels have been shown to increase three- to six-fold after flooding and remain above pre-impoundment levels for several decades (Bodaly et al.,; Schetagne and Therrien ). The extent of MeHg bioaccumulation at these sites was high enough to possibly impact fish reproduction and growth (Scheuhammer et al. ), although fish growth and yield may improve after reservoir formation in oligotrophic systems (Bilodeau et al. ). For Quebec reservoirs, peak MeHg levels occurred at 4–9 years for non-piscivorous fish and 9–11 years for piscivorous fish (Bilodeau et al. ). For hundreds of western US and Canadian reservoirs, the average peak in fish Hg occurred only 3 years after flooding, and rarely exceeded 3-fold of background (Willacker et al. ). Lower organic carbon stores (soil and vegetation) in western catchments relative to boreal areas may be a driver of these differences in fish Hg.

In addition to increased MeHg production following the initial flooding, the ongoing wetting and drying cycles, as well as reservoir drawdown, can continue to affect MeHg production in older reservoirs (Orem et al.; Eckley et al. ). During dry periods, reduced sulfur and organic matter stored in anaerobic soils can oxidize, fueling a pulse of MeHg production on each rewetting cycle. Additionally, sulfide production during wet periods modifies dissolved NOM with reduced sulfur moieties that enhance Hg availability for methylation (Graham et al.; Poulin et al. ). Sediment wetting and drying cycles can increase the breakdown of organic matter, which can result in increased partitioning of sediment-bound Hg into the porewater phase and increased dissolved organic carbon production, both of which have been shown to enhance Hg methylation in reservoirs (Eckley et al. ). Finally, reservoir water-level fluctuations have also been shown to increase sediment erosion and resuspension of Hg in the water column, which may make it more available for methylation (Mucci et al. ).

As noted above, observations of reservoirs in China have suggested less impact (relative to North American sites) on fish Hg concentrations (Larssen ). In addition to the relatively low organic matter content, the reservoirs in China had higher flow rates, shorter food webs, and biodilution and growth dilution that may contribute to lower fish Hg concentrations (Horvat et al.; He et al.; Feng et al.; Liu et al.; Li et al. ). However, unlike the research on reservoirs from North America, in which a decrease in fish Hg concentrations is predicted as the reservoir ages, reservoirs in China may experience an increase in MeHg production over time as sediment organic matter accumulates from both allochthonous and autochthonous sources (Feng et al. ). Autochthonous organic matter can increase as nutrients are trapped within the reservoir and the stagnant water conditions created by the reservoir increase the production of algal biomass.

Tools to predict the timing and magnitude of reservoir creation on MeHg accumulation in food webs can help guide resource management decisions (Calder et al. ). Early comparisons among Canadian and Finnish reservoirs showed that reservoir age, size, temperature, and organic matter content predicted the magnitude of the reservoir effect on MeHg bioaccumulation (Rudd et al.; Verta et al.; Bodaly et al. ). Simple regression models using percent of total reservoir area flooded, or the ratio of flooded area:volume were shown to predict 75–85 % of variability in fish Hg for northern Canadian reservoirs (Johnston et al.; Bodaly et al. ), especially if the upstream flooded area was included in the model. However, we still lack models that can reliably predict responses over a wide range of conditions.

The available data and models are heavily biased to boreal and temperate systems even though most current reservoir construction projects (and some of the largest reservoirs in the world) are located in the tropics and sub-tropics. Notably, boreal Canadian reservoirs may be a worst-case scenario for organic matter decomposition after flooding, due at least in part to large carbon stores in peat (St. Louis et al. ). Furthermore, model predictions of the impacts of reservoir creation can be complicated, even in the well-studied boreal forest region of Canada. For example, regression models of existing reservoirs suggest that the upper limit on peak increases in fish Hg within reservoirs is about six-fold above pre-impoundment levels (Johnston et al.; Bodaly et al. ). Another model that used a probabilistic approach incorporating a large variety of aquatic foods, site-specific bioaccumulation factors, and an explicit prediction of the impacts downstream of the reservoir predicted at 10-fold increase (Calder et al. ).

There are several options to minimize MeHg production during reservoir construction and ongoing management. Locations with Hg-contaminated soils or areas receiving high loads of Hg in runoff or via atmospheric deposition should be avoided as new reservoir construction sites. Multiple reservoirs constructed in series may compound MeHg accumulation (Feng et al. ). The harvesting of vegetation before flooding and extension of fill times could reduce peak MeHg concentrations after flooding (Kelly et al.; Hall and Louis; Mailman et al.; Willacker et al. ). With respect to long-term management of reservoirs, strategies that minimize large fluctuations in water levels between years and avoid drawdown of water storage during spring could minimize fish Hg. However, we recognize that these practices may be difficult with increasingly unpredictable precipitation patterns.

Though not unique to just reservoirs, management strategies in waterbodies aimed at altering redox conditions through oxygen or nitrate addition can also be utilized to reduce MeHg production (Matthews et al.; McCord et al. ). Other management actions aimed at decreasing MeHg production can include reducing the size and/or development of an anoxic hypolimnion using lake mixers or selective water withdrawals (Rask et al.; Perron et al.; Zouabi-Aloui et al. ). In addition, fish species can be stocked or removed in order to promote food web conditions that can decrease MeHg concentrations in target fish populations (Lepak et al.; Wolff et al. ).

Urbanization

Urban areas cover a relatively small percentage of the Earth’s surface, but are home to more than half of the world’s population and often include some commercial and subsistence fishing in adjoining and downstream waterways (Murkin et al.; Liu et al. ). Compared to rural/natural areas, concentrations of Hg have been shown to be elevated in urban air (Lindberg et al.; Kim et al.; Wip et al.; Fu et al. ), soil/street dust (Manta et al.; Ordonez et al.; Eckley and Branfireun; Huang et al.; Rodrigues et al. ), and waterbodies (Mason and Sullivan; Rice; Lawson et al.; Clark and Benoit; Barringer et al.; Rowland et al.; Tong et al.; Deonarine et al.; McKee and Gilbreath ). The level of Hg contamination in different urban areas can vary by over an order of magnitude, depending on the presence of current and historical industrial activities as well as local geographic and meteorological variables. In some residential and non-industrial urban areas, total Hg concentrations are not elevated compared to rural/natural areas (Naik and Hammerschmidt; Fleck et al. ).

In addition to differences in total atmospheric Hg concentrations, the proportion of atmospheric Hg that is particulate-bound in urban areas can be greater than in non-urban settings, resulting in enhanced deposition (Fu et al. ). The enrichment of particulate-bound Hg in urban air is likely a function of the proximity to emission sources and/or reactions with other urban area pollutants, such as oxidizing agents and airborne particulate matter. The deposition and accumulation of atmospheric Hg on urban impervious surfaces (e.g., buildings, roads, parking lots) often occurs in association with a thin layer of organic film from the dry deposition of gas phase pollutants (Diamond et al.; Gingrich and Diamond ). Hg deposited to urban surfaces is relatively labile and it is estimated that roughly half is released back to the air and the other half mobilized via runoff (Fig. 4). Due to the impervious nature of many urban surfaces, deposited Hg remains exposed to direct sunlight, resulting in photoreduction and evasion of Hg in urban areas (Gabriel et al.; Eckley and Branfireun ). Because of the high mobility of Hg in urban environments, the mass of Hg that remains on urban impervious surfaces can be very low even though the concentrations are high.

With the low infiltration capacity of urban landscapes, runoff often occurs as overland flow, which can effectively remove Hg associated with urban surfaces and entrain Hg-bearing street dust particles for transport to adjoining waterbodies (Vaze and Chiew; Fulkerson et al.; Eckley and Branfireun, ). In forested streams, dissolved NOM plays an important role in the transport of Hg in the dissolved phase (Brigham et al.; Stoken et al. ); in contrast, the dissolved organic matter content can be low in urban areas, with particulate-bound Hg dominating overall mass transport (Hurley et al.; Lawson et al.; Lyons et al.; Eckley and Branfireun ).

While total Hg can be very elevated in urban waterbodies, MeHg concentrations in street dust, sediment, and water have been shown to be relatively low (Huang et al. ), as have MeHg concentrations in fish (Scudder; Chalmers et al. ). In general, urban stormwater management focuses on the rapid conveyance of water away from the built environment, thus reducing water stagnation and the formation of anoxic conditions. With increased peak flows and erosion in urban waterways, conditions are significantly less favorable for methylation by anaerobic microbes in urban environments than in depositional environments. Higher nitrogen and lower dissolved NOM in urban streams may also contribute to the lower methylation potential in urban environments. Finally, the bioavailability of inorganic Hg for methylation in urban environments may be lower due to higher proportion of inorganic Hg bound to particles.

Low-impact development features and green infrastructure are common in new urban developments and are designed to reduce discharge to streams and improve water quality through particle settling. Examples include stormwater retention ponds, constructed wetlands, bioswales, permeable pavement, and green roofs. Retention ponds and other constructed wetlands have been shown to be very effective at reducing metal concentrations, including total Hg; however, they can also be net sources of MeHg (Stamenkovic et al.; Rumbold and Fink; Jang et al.; Strickman and Mitchell ). Similar to patterns observed in reservoirs, newly constructed retention ponds and wetlands differ considerably in their initial and long-term MeHg production capabilities as a function of age and organic matter content of the impounded soils (Sinclair et al.; Strickman and Mitchell ). The impact of MeHg from urban constructed wetlands depends on their scale and hydrological connectivity to other waterways; however, this has not yet been explored in the literature. In most circumstances, constructed urban wetlands are not likely to be a significant contributing source of MeHg to receiving water bodies.

Rice production

Agricultural production of rice and other managed agricultural wetlands can be a source of MeHg that bioaccumulates in local wildlife and release MeHg to downstream waterways (Ackerman and Eagles-Smith; Ackerman et al.; Alpers et al.; Rothenberg et al.; Windham-Myers et al., ). Moreover, rice consumption is another recently recognized MeHg exposure route for humans, especially for certain communities in Asia (Rothenberg et al. ). Rice is a major staple agricultural crop and provides the primary source of food energy for nearly half of the global population. Consequently, rice paddies are one of the most widely distributed land uses in certain regions of the world, such as South and East Asia (FAO ). Rice production methods can be grouped into broad categories that include irrigated rice, rainfed rice (rainfed lowland rice and rainfed upland rice), and flood-prone rice. Irrigated rice represents approximately 55 % of total area of rice cultivation and 77 % of the global rice production and often employs alternate wetting and drying cycles as a means to reduce freshwater consumption without decreasing yields (FAO ).

Rice cultivation can foster anaerobic and organic carbon-rich habitats that promote the growth of Hg-methylating microbes, resulting in conditions where MeHg can accumulate in rice crops (Meng et al., ). As a result, rice consumption has been shown to be the dominant pathway of MeHg exposure for certain communities (e.g., mining areas and certain inland areas of southern China) (Feng et al.; Zhang et al.; Li et al., ). Elevated concentrations of MeHg in rice grains (up to 140 µg/kg) have been reported in Indonesia (Krisnayanti et al. ) and in different parts of China (e.g., (Horvat et al.; Qiu et al.; Meng et al.,,,; Liang et al.; Tang et al. ). MeHg bioaccumulates in rice more readily than inorganic Hg, with bioaccumulation factors for MeHg that are 800–40 000 times higher than those for inorganic Hg (Meng et al.,,; Zhang et al. ). MeHg exposure via rice in other global regions is also a possibility, as described in a recent study that found moderate amounts of mercury in European rice products (Brombach et al. ).

Rice seeds have the highest ability to accumulate MeHg compared to the other tissues of the plant (e.g., root, stalk, and leaf), and rice paddy soils are the principal source of MeHg taken up by these plants (Meng et al.,; Strickman and Mitchell ). MeHg in soil can be taken up by plant roots and then translocated to the aboveground parts (leaf and stalk). In the premature plant, the majority of MeHg is stored in the leaf and stalk; however, most of this MeHg is transferred to the seed during the ripening period. On a mass basis, the majority of MeHg is found in edible white rice. During grain processing, most of the inorganic Hg (~ 78 %) is eliminated, but the majority of the MeHg remains in the food product (~80 %) (Meng et al. ). MeHg in whole rice seeds as well as the edible components exists almost exclusively as CH3Hg+ bonded to cysteine-like structures (Li et al.; Meng et al. ), in the form of individual CH3Hg-(L-cysteinate) complexes or as part of larger proteins containing cysteine moieties. This MeHg-cysteine association behaves like a mobile nutrient and is actively transported to the endosperm during seed ripening (Meng et al. ). We also note that the CH3Hg-(L-cysteinate) complex is thought to be responsible for the transfer of MeHg across the blood–brain and placental barriers (Kerper et al.; Kajiwara et al.; Simmons-Willis et al.; Clarkson et al. ).

In addition to the concern for MeHg exposure via rice consumption, rice agriculture can also be a source of MeHg to downstream ecosystems. Net export of MeHg from rice fields has been estimated in some locations, although this phenomenon may vary within each growing season (Bachand et al.; Windham-Myers et al.; Tanner et al. ).

Management strategies to reduce MeHg in rice must be balanced with the need to maximize crop production. Water management strategies such as intermittent flooding might alter anaerobic Hg-methylating microbes relative to continuously flooded rice fields (Rothenberg et al.,,; Peng et al.; Alpers et al.; Wang et al. ). Selenium (Se)-enriched paddy soils have been shown to reduce MeHg production in paddy soils, which may be related to the formation of Hg-Se complexes in the rhizosphere (Zhang et al.,; Wang et al. ). Thus, Se amendments have been proposed as a means to reduce the absorption and accumulation of MeHg in rice grains in areas of high Hg contamination (Zhao et al.; Wang et al. ). However, this approach requires caution due to the known impacts of Se on wildlife (Simmons and Wallschläger ). Different rice cultivars also vary considerably in grain concentrations of MeHg, suggesting that appropriate cultivar selection could reduce MeHg accumulation and exposure in Hg-contaminated areas (Peng et al.; Rothenberg and Feng; Li et al. ). The selection of non-rice food agricultural crops (e.g., corn, rape, tobacco, and cabbage) could be another solution, as these crops do not accumulate MeHg to the same extent as observed for rice (although inorganic Hg accumulation would still occur) (Qiu et al. ).

Future research on the impacts of rice production for MeHg release to the environment and rice consumption for human Hg exposure should examine geographically diverse areas, including Asian countries beyond China as well as other major continents where rice production and consumption is substantial. Such data are critical in assessing the potential health risks associated with rice cultivation in Hg-contaminated soils. While the source, distribution, and accumulation of MeHg in rice plants, as well as transport and transformation of Hg species within paddy fields, have been previously studied, the processes of Hg methylation in rice fields and the controlling factors are not fully understood. Furthermore, uptake and translocation pathways and the detoxification of MeHg in rice plant are still unknown. As is the case in other ecosystems, newly deposited Hg may be more readily transformed to MeHg in rice paddies than older Hg (Meng et al., ). However, the mechanisms behind this phenomenon are not well understood, and the link between MeHg concentrations in rice and atmospheric Hg deposition requires further investigation.

Gold mining and other mining activities

Hg releases associated with mining can encompass a broad range of activities, including contemporary artisanal small-scale gold mining (ASGM), historical mines, and contemporary industrialized mines. ASGM generally involves the utilization of Hg (often imported from other regions) for amalgamation and extraction of gold and other precious metals from ore. ASGM relies on unmechanized gold recovery and in some cases small and heavy equipment use by individuals and small groups (rather than multinational corporate entities that operate industrialized mines). Historically, the same Hg amalgamation process was used at larger scale gold and silver mines (e.g., Sierra range of North America, Potosí). The legacy of these activities and the former Hg mine sites such as Almaden, Idrija, Huancavelica, and the coastal range of California have ongoing environmental inputs of Hg to downstream locations (Rytuba; Foucher et al.; Hagan et al.; Jimenez-Moreno et al. ).

ASGM is currently active in more than 70 countries, where it is typically little acknowledged, unregulated, or illegal (Veiga et al.; Telmer and Veiga; Swenson et al.; Reichelt-Brushett et al. ). Collectively this practice represents a major global emission source of Hg to the atmosphere, with estimates ranging from 20 to 37 % of total anthropogenic Hg emissions (Lacerda; Pirrone et al.; United Nations Environment Programme ). These estimations often rely on a mass balance approach for regional imports and exports and can have a high degree of uncertainty given the lack of reliable information (Malm; Lacerda; Li et al.,; Telmer and Veiga; Grimaldi et al. ) and few examples of directly quantified Hg emissions (Amouroux et al.; Balzino et al. ). ASGM also increases health risks for workers (Gibb and O’Leary; Kristensen et al.; Castilhos et al. ) and riparian populations downstream of mining sites (Lebel et al.; Grandjean et al.; Maurice-Bourgoin et al.; Bastos et al.; Diringer et al. ), as described in a companion paper (Eagles-Smith et al. ).

The type of ASGM techniques (such as material collection, processing, and disposal techniques) and the extent of accidental spills govern the amount of Hg release to the surrounding environment (Telmer and Veiga; Balzino et al. ). Increases in local soil Hg content (Malm et al.; van Straaten ) and soil erosion rates are common features of many ASGM areas (Swenson et al. ), and together are the key aspects influencing Hg transport and exposure to downstream communities. Extensive deforestation is often associated with ASGM and could further contribute to soil erosion and Hg export from watersheds. However, the impact of deforestation on Hg transport (relative to inadvertent release and deposition of Hg from the mining itself) requires further examination, perhaps by combining remote sensing data (e.g., satellite land cover) and field observations of Hg mobilization in watersheds (Swenson et al.; Diringer et al.; Lobo et al. ). The significance of terrestrial Hg inputs from ASGM relative to direct atmospheric deposition of Hg to waterbodies near ASGM (Fig. 3) could provide information for the assessment of other systems and insights for Hg exposure mitigation.

While ASGM and related processes (e.g., deforestation, soil erosion, urbanization) are known to increase the transport of Hg in watersheds, related impacts on biogeochemical transformations of Hg are also important to consider (Boudou et al.; Alanoca et al. ). The chemical forms of Hg mobilized from recently deforested areas may differ from other terrestrial sources, and this difference may be relevant for Hg methylation and MeHg bioaccumulation. Some ASGM operations utilize cyanide in conjunction with Hg amalgamation, perhaps to reduce Hg usage or as a replacement for Hg. Environmental releases of cyanide have been hypothesized to alter methylation of Hg in downstream receiving waters perhaps by suppressing the biological activity of methylators (Tarras-Wahlberg et al.; Guimaraes et al. ). This hypothesis remains to be fully investigated.

Compared to ASGM and historical mining, contemporary industrial mining operations are distinct in terms of their impacts on Hg cycling, most notably because they do not use Hg as part of the ore extraction process. However, these mines can increase mobilization of Hg if the orebody of interest is naturally enriched in Hg (typically gold mines as well as some copper and zinc mines). Hg can be released during ore processing via stack emissions and water discharges, but these are typically regulated and can be reduced through traditional pollution control technologies. However, fugitive surface-to-air fluxes from the ore, tailings, and waste rock piles can be a significant source of emissions from mines (Eckley et al. ). Because of the large surface area covered by many contemporary industrial mines, the annual surface-to-air emissions scaled over an entire mine site can be > 100 kg/year (Eckley et al. ). These surface emissions can be substantially reduced by capping mine waste with a thin layer of low-Hg topsoil and/or applying Hg control reagents to the mine wastes, though the latter approach needs further evaluation under field conditions (Eckley et al.; Miller and Gustin ).

In addition to direct emission of Hg to the air, mine operations can also impact Hg methylation in downstream aquatic systems by providing a substantial source of sulfate to receiving waterbodies (Berndt et al.; Bailey et al. ) and by altering the surrounding hydrology as a result of dewatering around the mine pit/tunnels during operations and subsequent rewetting after closure (Willacker et al.; Eckley et al. ). The drawdown and wetting cycles yield similar impacts on Hg methylation as that noted for reservoirs. After the stoppage of operations at open pit mines, the resulting deep pit lakes are susceptible to stratification, very high sulfate levels, and low organic carbon levels that have implications for MeHg production (Meier et al.; Gammons et al. ).

Strategies to manage Hg release from historical and contemporary mining activities remain an ongoing challenge, mainly due to persistent and long-term inputs to ecosystems and broad geographic distribution of the impact. For example, some of the highest fish Hg concentrations in Canada are associated with areas where Hg was historically used to extract gold (Lockhart et al. ). Similarly, Hg pollution related to historical Hg mines and use of Hg for gold mining during the California gold rush during the mid-1800 s continues to be a concern for downstream waterbodies (May et al.; Alpers et al. ). For contemporary ASGM, alternatives to Hg (such as cyanide and borax) have been suggested, but they also represent additional challenges, particularly for subsistence miners with limited resources (Hidayati et al.; Spiegel and Veiga; Velásquez-López et al.; Veiga et al.; Cordy et al.; Køster-Rasmussen et al. ). The agreements outlined in the Minamata Convention may help to regulate Hg trade (see companion paper (Selin et al. ); however, the impact on unregulated Hg markets remains uncertain. Overall, effective management of contemporary ASGM requires a comprehensive approach that takes into consideration the environmental impacts of concurrent activities as well as socioeconomic constraints in applying management strategies.

Industrial point sources and remediation

Historical Hg contamination from industrial sources represents a major challenge to address for site managers and neighboring communities who are vulnerable to Hg exposure. In addition to sites impacted by mining, other types of industrial Hg contamination include waste discharged from chlor-alkali processing facilities, pulp/paper mills, oil/gas production sites, and chemical production facilities. The age of the contamination at any single site is often several decades old (although newer industrial contamination still occurs in areas without close monitoring or established environmental regulations). Impacted sites include terrestrial sites as well as surface waters where Hg is typically concentrated in sediments (Lindeström; Bloom et al.; New York State Department of Environmental Conservation and U.S. Environmental Protection Agency; Tomiyasu et al.; Skyllberg et al.; Ullrich et al.,; Bravo et al.,; Balogh et al. ). Industrially impacted sites also include subsurface zones where groundwater discharge of Hg into surface waters is a concern (Flanders et al.; Southworth et al. ). In many of these systems, total Hg content in soil and sediment is enriched by orders of magnitude relative to other ecosystems where Hg is also a concern (Fig. 1). In some exceptional cases, exposure to inorganic Hg from soil or vapors may pose a direct health risk (Robins et al.; Hagan et al., ). Nevertheless, most industrially polluted sites raise concerns because of MeHg bioaccumulation, mobilization of Hg to downstream locations, and/or evasion of Hg to the atmosphere. We note that our search of the published literature on industrially contaminated sites revealed sediment MeHg contents that tended to be greater than other types of sites with comparable total Hg content (e.g., mining sites) (Fig. 1). This observation might be reflective of research activities that prioritize towards sites with potential health risks (i.e., sites with high levels of MeHg production and bioaccumulation) relative to other industrial sites with little MeHg impact.

The management of industrially contaminated locations requires assessment of Hg contamination and risk, followed by the development of strategies for remediation or long-term management (Randall and Chattopadhyay; Bigham et al. ). In the course of developing a management and monitoring strategy, managers first quantify all sources of Hg to the system, identify areas of high exposure risk (e.g., high Hg or MeHg concentrations), and formulate benchmark goals for addressing the problems on the path towards a remedial action plan. These decisions require models (conceptual and/or numeric) that can be used to understand relevant processes for Hg fate, and perhaps, more importantly, delineate the uncertainties for risk. In many instances, the evaluation of a site may reveal that the risk of Hg is declining over time (e.g., due to the aging of Hg), and an understanding of these trends can help guide decisions to implement active or passive (and typically less disruptive) strategies for ecosystem recovery. Industrial sites can also have multiple pollutants, in addition to Hg, that drive exposure risks, and the best remediation and management decisions for one target pollutant could increase the risks posed by other targets.

Natural recovery of a system (with appropriate monitoring) is often the best option for large-scale industrial sites experiencing decreasing trends in Hg reactivity and bioavailability. This passive approach is often justified not only by its lower cost, but also by minimizing disruption to the ecosystem, which can be a negative consequence of more active remediation approaches. Active strategies include ex situ methods such as dredging and excavation for remediation of high priority Hg hotspots (Rudd et al. ). For sites of lower Hg enrichment and broad spatial extent, in situ methods have garnered substantial interest in recent years due to the inherently less disruptive impact of these methods on the surrounding ecosystem, the potential for long-term mitigation, and the reduction in costs relative to dredging and excavation (Ghosh et al.; Wang et al. ). For example, sediment caps may be used for stream bank stabilization and erosion control (generally aiming to halt or minimize mobilization of Hg-bearing particles) (Wang et al.; Johnson et al. ). In situ amendments involve addition of chemicals or materials directly to soil or sediments to alter the biogeochemical conditions of the site. For example, nitrate amendments and active oxygenation of reservoirs have successfully been used to artificially elevate the redox potential of the water column as a means to eliminate or bury the anaerobic zone that fosters MeHg producing microorganisms (Matthews et al.; Beutel et al. ). Other amendments such as black carbon sorbents and ferrous iron aim to sequester Hg in sediment/soil and reduce the Hg and MeHg solubility and bioavailability for uptake (Mehrotra and Sedlak; Ulrich and Sedlak; Gilmour et al.; Gomez-Eyles et al. ). We note, however, that the impact of these processes on Hg speciation remains poorly understood. For example, the addition of activated carbon has been shown to decrease, increase, or not change overall levels of MeHg in sediment microcosms (Gilmour et al. ). These responses might reflect reductions in Hg bioavailability for methylation, reduction of MeHg availability for demethylation, or alterations to the microbial community that are essential to these processes. Nevertheless, activated carbon amendments are a promising option in some cases for reducing MeHg bioavailability to benthic biota.

Many challenges remain in the development of effective Hg management strategies for industrially polluted sites. Innovative tools for source attribution and risk assessment are in great need and remain an active area of research. For cases where monitored natural attenuation of Hg is insufficient, in situ remediation technologies such as chemical amendments and sediment caps are promising; however, the implementation of these methods is, for the most part, currently limited to lab scale and pilot-scale testing. Full-scale implementation will require a better understanding of the long-term effects of in situ technologies as well as methods to evaluate site characteristics that inform the remediation selection process.

Summary of management opportunities and research needs

A wide variety of anthropogenic and natural perturbations to landscapes have significant impacts on Hg cycling in watersheds (summarized in Table 1). These impacts are of concern if they increase Hg exposure risks to humans and wildlife. As such, water quality criteria for Hg tend to consist of fish-based MeHg content, rather than an aquatic or soil Hg/MeHg value. While this approach for regulation provides a direct connection between exposure and risk, this type of criterion does not inform clear ecosystem management strategies.

As noted in the preceding sections, a specific remedial action or ecosystem perturbation requires the consideration of widely variable response times (e.g., years to decades) for the biogeochemical processes leading to MeHg bioaccumulation; understanding the time scales may be the critical factor in choosing any local Hg mitigation strategy. Knowledge of the relative sources of Hg input (e.g., surface versus terrestrial loading as shown in Fig. 3) could offer managers insights on the variety of Hg sources to a specific site, the relative response times for control of these sources, and ecosystem management strategies to minimize MeHg bioaccumulation.

Whole water or soil/sediment total Hg or MeHg concentration criteria might be helpful as a shorter-term gauge of management effectiveness, but sediment/soil Hg criteria could be misleading in that total Hg and MeHg concentrations do not necessarily correlate with MeHg bioaccumulation. As such, criteria based on a “bioavailable” fraction of total Hg, bioavailable MeHg, and net Hg methylation potential should be considered as we improve the functionality of metrics for water quality management.

Approaches for assessing the potential of Hg mobilization and net methylation at sites remain a challenge. However, recent gains in scientific knowledge could be utilized by site managers. For example, the mobilization of Hg to downstream and downgradient locations is often linked to the mobilization of particles (Flanders et al. ). Thus, Hg levels can be predicted by particle loadings. [We note that sites impacted by liquid elemental Hg0 contamination are an exception, where mobilization is influenced by dissolution and corrosion rates of discrete Hg0 phases in addition to transport of secondary mineral particles (Southworth et al. ).] Natural organic matter can facilitate particle transport by coating particles and reducing colloidal aggregation and deposition rates. Moreover, recent research has demonstrated that this effect varies with the quality of the NOM (e.g., molecular weight, chemical structure) (Deonarine et al.; Philippe and Schaumann; Louie et al., ). Optical properties of dissolved NOM such as specific UV absorbance and fluorescence signatures could enable the use of real-time sensors deployed in surface waters as proxies for dissolved and colloidal Hg transport (Dittman et al.,; Burns et al. ).

New tools are also in development to enable meaningful monitoring information of Hg transformation potential and source attribution. For example, stable Hg isotope signatures are a promising tool to delineate Hg inputs from multiple sources (Liu et al.; Bartov et al.; Deonarine et al.; Sherman et al.; Wiederhold et al. ). However, the application of Hg isotopes requires measurements of the appropriate “endmember” samples as well as an understanding of the extent of isotopic fractionation that could occur from a variety of biogeochemical transformation processes at the site. The deconvolution of fractionation processes represents the major hurdle in applying Hg isotopes information to source apportionment.

Recent advances in our understanding of microbial Hg methylation may enable the development of new tools to monitor and quantify net MeHg production potential at field sites and perhaps predict the impact of various remediation strategies. For example, the discovery of the hgcAB gene cluster in methylating microorganisms has led to new biomolecular tools to quantify the abundance, and perhaps activity of methylating microbes in nature (Gilmour et al.; Parks et al.; Podar et al.; Christensen et al. ).

Methods to quantify the reactivity of Hg and bioavailability of Hg to methylating microbes, such as chemical equilibrium models or selective extractions, have been tested over the years, but with limited success (Hsu-Kim et al.; Ticknor et al. ). These results might be explained by the complexity of Hg-sulfide-NOM species in soil and sediment, which include nanostructured particulate phases of varying reactivity (e.g., dissolution potential) in anaerobic settings (as shown in Fig. 2). Hg uptake into methylating microbes is likely to involve an active membrane transport process (Schaefer et al., ), and not simply uptake of neutral Hg-sulfide solutes (Benoit et al. ). For this reason, as well as challenges in differentiating between dissolved solutes and colloidal particles in water samples, chemical equilibrium models of neutral Hg species are no longer employed by the scientific community to ascertain Hg bioavailability to methylating bacteria (Hsu-Kim et al. ).

Instead, alternative markers to quantify Hg reactivity and bioavailability are needed, especially models or biologically relevant measurements that can accommodate the spectrum of Hg species in soil and sediment and are consistent with the process by which methylating microbes take up Hg (Ticknor et al. ). While several methods to quantify a nominally “reactive” fraction of Hg have been proposed (Bloom et al.; Marvin-DiPasquale et al.; Liang et al.; Ticknor et al. ), the measurements must be interpreted with great care because this reactivity may not necessarily be relevant to processes influencing bioavailability. Moreover, these methods generally have not been explicitly evaluated in experiments that compare reactivity and Hg bioavailability for methylators. Likewise, the use of stable isotope spike experiments to assess the net Hg methylation rate potential has uncertainties because the outcome of these assays are highly subjective towards methodology (i.e., chemical form of the Hg spike, incubation time and conditions) and unknown changes in speciation of the Hg spike in relation to the form of ambient Hg at the site.

While tremendous progress has been made in understanding the process of microbial Hg methylation, the mechanism of Hg uptake, how the rates of Hg methylation vary among the diverse species of methylating microbes, and if their abundance or activity correlate to methylation rates remain unknown. The process of dark MeHg degradation in benthic zones remains an even greater mystery and requires more attention by the research community, especially since remediation of contaminated sites might need to focus on strategies to enhance MeHg degradation. With progress in the understanding of processes that contribute to Hg mobilization and net MeHg production, novel methods for effective and lasting remediation and monitoring technologies are within reach.

Transformational improvements to Hg site management, such as those outlined above, will take time, but the need for comprehensive risk assessment tools remain urgent. Typical site assessments attempt to account for all Hg inputs and outputs in the system, which enables an understanding of primary sources and sinks. Other parameters such as the concentrations and fluxes of sulfate, organic carbon, filter-passing Hg and MeHg fractions, dissolved and total sulfide, and redox potential, among others, could provide insight into the factors controlling rates of MeHg production, degradation, and food web bioaccumulation and biomagnification. In some cases, measurements of isotope ratios of Hg, the bioavailable fraction of Hg, and the soil/water microbiomes might be justified as the development and applications of these tools improve with additional research. Advanced data analysis techniques should be utilized to help us discern large datasets of parameters interlinked by non-linear and poorly defined relationships.

Global-scale perturbations such as climate change will have local-scale effects such as rising sea level, melting tundra soils, and altered and extreme precipitation regimes. Impacts could include large releases of soluble organic matter, mobilization of Hg-bearing particles, and redox fluctuations and gradients, all of which can ultimately impact MeHg bioaccumulation as discussed in previous sections.

Overall, this synthesis paper outlined the effects of major anthropogenic landscape perturbations on the distribution and methylation of Hg in aquatic ecosystems. Much of the research over recent decades has had a relatively narrow geographical focus (e.g., North America, Europe, parts of Asia); however in other locations (Latin America, Africa, Asia Pacific), large populations continue to be vulnerable to the negative health consequences of MeHg exposure. Insights from the existing research literature can provide insights into the development of substantive approaches to mitigate Hg distribution and exposure in understudied regions. Regardless, research in these regions is still sorely needed, particularly in tropical environments that have received much less attention in the Hg biogeochemical research field. Altogether, global- and local-scale perturbations to landscapes alter the transport and transformations of Hg in complex ways, and an understanding of this complexity is needed to guide international and regional efforts to manage and monitor reductions in MeHg exposure to populations.

Below is the link to the electronic supplementary material.

References 367

  1. 1.

    Achá D, Hintelmann H, Yee J. Importance of sulfate reducing bacteria in mercury methylation and demethylation in periphyton from Bolivian Amazon region. Chemosphere. 2011;82:911-916.

    Not in our library10.1016/j.chemosphere.2010.10.050

  2. 2.

    Ackerman JT, Eagles-Smith CA. Agricultural wetlands as potential hotspots for mercury bioaccumulation: Experimental evidence using caged fish. Environmental Science and Technology. 2010;44:1451-1457.

    Not in our library10.1021/es9028364

  3. 3.

    Ackerman JT, Miles AK, Eagles-Smith CA. Invertebrate mercury bioaccumulation in permanent, seasonal, and flooded rice wetlands within California’s Central Valley. Science of the Total Environment. 2010;408:666-671.

    Not in our library10.1016/j.scitotenv.2009.10.030

  4. 4.

    Aiken, G., M. Ravichandran, M. Reddy, J. N. Ryan, and J. Tregellas. 1998. Interactions of dissolved organic carbon with mercury in the Everglades, Florida. Abstracts of Papers of the American Chemical Society 216:025-ENVR.

    Not in our library

  5. 5.

    Aiken GR, Hsu-Kim H, Ryan JN. Influence of dissolved organic matter on the environmental fate of metals, nanoparticles, and colloids. Environmental Science and Technology. 2011;45:3196-3201.

    Not in our library10.1021/es103992s

  6. 6.

    Akerblom S, Bishop K, Bjorn E, Lambertsson L, Eriksson T, Nilsson MB. Significant interaction effects from sulfate deposition and climate on sulfur concentrations constitute major controls on methylmercury production in peatlands. Geochimica et Cosmochimica Acta. 2013;102:1-11.

    Not in our library10.1016/j.gca.2012.10.025

  7. 7.

    Alanoca L, Guédron S, Amouroux D, Audry S, Monperrus M, Tessier E, Goix S, Acha D, et al. Synergistic effects of mining and urban effluents on the level and distribution of methylmercury in a shallow aquatic ecosystem of the Bolivian Altiplano. Environmental Science: Processes & Impacts. 2016;18:1550-1560.

    Not in our library10.1039/c6em00547k

  8. 8.

    Allan CJ, Heyes A, Mackereth RJ. Changes to groundwater and surface water Hg transport following clearcut logging: A Canadian case study. Royal Swedish Academy of Agriculture and Forestry. 2009;148:50-54.

    Not in our library

  9. 9.

    Alpers, C. N., M. P. Hunerlach, M. C. Marvin-DiPasquale, R. C. Antweiler, B. K. Lasorsa, J. F. De Wild, and N. P. Snyder. 2006. Geochemical data for mercury, methylmercury, and other constituents in sediments from Englebright Lake, California, 2002.

    Not in our library

  10. 10.

    Alpers CN, Fleck JA, Marvin-DiPasquale M, Stricker CA, Stephenson M, Taylor HE. Mercury cycling in agricultural and managed wetlands, Yolo Bypass, California: Spatial and seasonal variations in water quality. Science of the Total Environment. 2014;484:276-287.

    Not in our library10.1016/j.scitotenv.2013.10.096

  11. 11.

    Amouroux D, Wasserman JC, Tessier E, Donard OFX. Elemental mercury in the atmosphere of a Tropical Amazonian Forest (French Guiana). Environmental Science and Technology. 1999;33:3044-3048.

    Not in our library10.1021/es990119b

  12. 12.

    Amyot M, Mierle G, Lean D, Mc Queen DJ. Effect of solar radiation on the formation of dissolved gaseous mercury in temperate lakes. Geochimica et Cosmochimica Acta. 1997;61:975-987.

    Not in our library10.1016/s0016-7037(96)00390-0

  13. 13.

    Austin D, Scharf R, Carroll J, Enochs M. Suppression of hypolimnetic methylmercury accumulation by liquid calcium nitrate amendment: Redox dynamics and fate of nitrate. Lake and Reservoir Management. 2016;32:61-73.

    Not in our library10.1080/10402381.2015.1121306

  14. 14.

    Avramescu M-L, Yumvihoze E, Hintelmann H, Ridal J, Fortin D, Lean DRS. Biogeochemical factors influencing net mercury methylation in contaminated freshwater sediments from the St. Lawrence River in Cornwall, Ontario, Canada. Science of the Total Environment. 2011;409:968-978.

    Not in our library10.1016/j.scitotenv.2010.11.016

  15. 15.

    Babiarz C, Hoffmann S, Wieben A, Hurley J, Andren A, Shafer M, Armstrong D. Watershed and discharge influences on the phase distribution and tributary loading of total mercury and methylmercury into Lake Superior. Environmental Pollution. 2012;161:299-310.

    Not in our library10.1016/j.envpol.2011.09.026

  16. 16.

    Bachand PAM, Bachand SM, Fleck JA, Alpers CN, Stephenson M, Windham-Myers L. Methylmercury production in and export from agricultural wetlands in California, USA: The need to account for physical transport processes into and out of the root zone. Science of the Total Environment. 2014;472:957-970.

    Not in our library10.1016/j.scitotenv.2013.11.086

  17. 17.

    Bailey LT, Mitchell CPJ, Engstrom DR, Berndt ME, Wasik JKC, Johnson NW. Influence of porewater sulfide on methylmercury production and partitioning in sulfate-impacted lake sediments. Science of the Total Environment. 2017;580:1197-1204.

    Not in our library10.1016/j.scitotenv.2016.12.078

  18. 18.

    Balogh SJ, Swain EB, Nollet YH. Characteristics of mercury speciation in Minnesota rivers and streams. Environmental Pollution. 2008;154:3-11.

    Not in our library10.1016/j.envpol.2007.11.014

  19. 19.

    Balogh SJ, Tsui MT-K, Blum JD, Matsuyama A, Woerndle GE, Yano S, Tada A. Tracking the fate of mercury in the fish and bottom sediments of Minamata Bay, Japan, using stable mercury isotopes. Environmental Science and Technology. 2015;49:5399-5406.

    Not in our library10.1021/acs.est.5b00631

  20. 20.

    Balzino M, Seccatore J, Marin T, De Tomi G, Veiga MM. Gold losses and mercury recovery in artisanal gold mining on the Madeira River, Brazil. Journal of Cleaner Production. 2015;102:370-377.

    Not in our library10.1016/j.jclepro.2015.05.012

  21. 21.

    Barkay T, Wagner-Dobler I, Laskin AI, Bennett JW, Gadd GM. Microbial transformations of mercury: Potentials, challenges, and achievements in controlling mercury toxicity in the environment. Advances in Applied Microbiology. 2005;1-52.

    Not in our library10.1016/s0065-2164(05)57001-1

  22. 22.

    Barringer JL, Riskin ML, Szabo Z, Reilly PA, Rosman R, Bonin JL, Fischer JM, Heckathorn HA. Mercury and methylmercury dynamics in a coastal plain watershed, New Jersey, USA. Water, Air, and Soil pollution. 2010;212:251-273.

    Not in our library10.1007/s11270-010-0340-1

  23. 23.

    Bartov G, Deonarine A, Johnson TM, Ruhl L, Vengosh A, Hsu-Kim H. Environmental impacts of the Tennessee Valley Authority Kingston Coal Ash Spill. 1. Source apportionment using mercury stable Isotopes. Environmental Science and Technology. 2013;47:2092-2099.

    Not in our library10.1021/es303111p

  24. 24.

    Bastos WR, Gomes JPO, Oliveira RC, Almeida R, Nascimento EL, Bernardi JVE, de Lacerda LD, da Silveira EG, et al. Mercury in the environment and riverside population in the Madeira River Basin, Amazon, Brazil. Science of the Total Environment. 2006;368:344-351.

    Not in our library10.1016/j.scitotenv.2005.09.048

  25. 25.

    Beliveau A, Lucotte M, Davidson R, Lopes LOD, Paquet S. Early Hg mobility in cultivated tropical soils one year after slash-and-burn of the primary forest, in the Brazilian Amazon. Science of the Total Environment. 2009;407:4480-4489.

    Not in our library10.1016/j.scitotenv.2009.04.012

  26. 26.

    Benoit JM, Gilmour CC, Mason RP, Heyes A. Sulfide controls on mercury speciation and bioavailability to methylating bacteria in sediment pore waters. Environmental Science and Technology. 1999;33:951-957.

    Not in our library10.1021/es9808200

  27. 27.

    Berndt ME, Rutelonis W, Regan CP. A comparison of results from a hydrologic transport model (HSPF) with distributions of sulfate and mercury in a mine-impacted watershed in northeastern Minnesota. Journal of Environmental Management. 2016;181:74-79.

    Not in our library10.1016/j.jenvman.2016.05.067

  28. 28.

    Beutel M, Dent S, Reed B, Marshall P, Gebremariam S, Moore B, Cross B, Gantzer P, et al. Effects of hypolimnetic oxygen addition on mercury bioaccumulation in Twin Lakes, Washington, USA. Science of the Total Environment. 2014;496:688-700.

    Not in our library10.1016/j.scitotenv.2014.06.117

  29. 29.

    Beutel MW, Duvil R, Cubas FJ, Matthews DA, Wilhelm FM, Grizzard TJ, Austin D, Horne AJ, et al. A review of managed nitrate addition to enhance surface water quality. Critical Reviews in Environmental Science and Technology. 2016;46:673-700.

    Not in our library

  30. 30.

    Bigham GN, Murray KJ, Masue-Slowey Y, Henry EA. Biogeochemical controls on methylmercury in soils and sediments: Implications for site management. Integrated Environmental Assessment and Management. 2017;13:249-263.

    Not in our library10.1002/ieam.1822

  31. 31.

    Bilodeau F, Schetagne R, Therrien J, Verdon R. Absence of noticeable mercury effects on fish populations in boreal reservoirs despite threefold to sevenfold increases in mercury concentrations. Canadian Journal of Fisheries and Aquatic Sciences. 2015;73:1104-1125.

    Not in our library10.1139/cjfas-2015-0035

  32. 32.

    Black FJ, Poulin BA, Flegal AR. Factors controlling the abiotic photo-degradation of monomethylmercury in surface waters. Geochimica et Cosmochimica Acta. 2012;84:492-507.

    Not in our library10.1016/j.gca.2012.01.019

  33. 33.

    Bloom NS, Preus E, Katon J, Hiltner M. Selective extractions to assess the biogeochemically relevant fractionation of inorganic mercury in sediments and soils. Analytica Chimica Acta. 2003;479:233-248.

    Not in our library10.1016/s0003-2670(02)01550-7

  34. 34.

    Bloom NS, Moretto LM, Ugo P. A comparison of the speciation and fate of mercury in two contaminated coastal marine ecosystems: The Venice Lagoon (Italy) and Lavaca Bay (Texas). Limnology and Oceanography. 2004;49:367-375.

    Not in our library10.4319/lo.2004.49.2.0367

  35. 35.

    Bodaly RA, Rudd JWM, Fudge RJP, Kelly CA. Mercury concentrations in fish related to size of remote canadian shield lakes. Canadian Journal of Fisheries and Aquatic Sciences. 1993;50:980-987.

    Not in our library10.1139/f93-113

  36. 36.

    Bodaly RA, Beaty KG, Hendzel LH, Majewski AR, Paterson MJ, Rolfhus KR, Penn AF, Louis VLS, et al. Peer reviewed: Experimenting with hydroelectric reservoirs. Environmental Science and Technology. 2004;38:346A-352A.

    Not in our library10.1021/es040614u

  37. 37.

    Bodaly RA, Jansen WA, Majewski AR, Fudge RJ, Strange NE, Derksen AJ, Green DJ. Postimpoundment time course of increased mercury concentrations in fish in hydroelectric reservoirs of northern Manitoba, Canada. Archives of Environmental Contamination and Toxicology. 2007;53:379-389.

    Not in our library10.1007/s00244-006-0113-4

  38. 38.

    Boudou A, Maury-Brachet R, Coquery M, Durrieu G, Cossa D. Synergic effect of gold mining and damming on mercury contamination in fish. Environmental Science and Technology. 2005;39:2448-2454.

    Not in our library10.1021/es049149r

  39. 39.

    Braaten HFV, de Wit HA. Effects of disturbance and vegetation type on total and methylmercury in boreal peatland and forest soils. Environmental Pollution. 2016;218:140-149.

    Not in our library10.1016/j.envpol.2016.08.029

  40. 40.

    Branfireun BA, Roulet NT, Kelly C, Rudd JW. In situ sulphate stimulation of mercury methylation in a boreal peatland: Toward a link between acid rain and methylmercury contamination in remote environments. Global Biogeochemical Cycles. 1999;13:743-750.

    Not in our library10.1029/1999gb900033

  41. 41.

    Bravo AG, Loizeau J-L, Ancey L, Ungureanu VG, Dominik J. Historical record of mercury contamination in sediments from the Babeni Reservoir in the Olt River, Romania. Environmental Science and Pollution Research. 2009;16:66-75.

    Not in our library10.1007/s11356-008-0057-5

  42. 42.

    Bravo AG, Cosio C, Amouroux D, Zopfi J, Chevalley P-A, Spangenberg JE, Ungureanu V-G, Dominik J. Extremely elevated methyl mercury levels in water, sediment and organisms in a Romanian reservoir affected by release of mercury from a chlor-alkali plant. Water Research. 2014;49:391-405.

    Not in our library10.1016/j.watres.2013.10.024

  43. 43.
  44. 44.

    Brigham ME, Krabbenhoft DP, Olson ML, DeWild JF. Methylmercury in flood-control impoundments and natural waters of northwestern minnesota, 1997-99. Water, Air, and Soil pollution. 2002;138:61-78.

    Not in our library10.1023/a:1015573621474

  45. 45.

    Brigham ME, Wentz DA, Aiken GR, Krabbenhoft DP. Mercury cycling in stream ecosystems. 1. Water column chemistry and transport. Environmental Science and Technology. 2009;43:2720-2725.

    Not in our library10.1021/es802694n

  46. 46.

    Brombach C-C, Manorut P, Kolambage-Dona PP, Ezzeldin MF, Chen B, Corns WT, Feldmann J, Krupp EM. Methylmercury varies more than one order of magnitude in commercial European rice. Food Chemistry. 2017;214:360-365.

    Not in our library10.1016/j.foodchem.2016.07.064

  47. 47.

    Brown KR, McGuire KJ, Aust WM, Hession WC, Dolloff CA. The effect of increasing gravel cover on forest roads for reduced sediment delivery to stream crossings. Hydrological Processes. 2015;29:1129-1140.

    Not in our library10.1002/hyp.10232

  48. 48.

    Burns DA, Aiken GR, Bradley PM, Journey CA, Schelker J. Specific ultra-violet absorbance as an indicator of mercury sources in an Adirondack River basin. Biogeochemistry. 2013;113:451-466.

    Not in our library10.1007/s10533-012-9773-5

  49. 49.

    Calder RS, Schartup AT, Li M, Valberg AP, Balcom PH, Sunderland EM. Future impacts of hydroelectric power development on methylmercury exposures of Canadian indigenous communities. Environmental Science and Technology. 2016;50:13115-13122.

    Not in our library10.1021/acs.est.6b04447

  50. 50.

    Castilhos Z, Rodrigues-Filho S, Cesar R, Rodrigues AP, Villas-Bôas R, de Jesus I, Lima M, Faial K, et al. Human exposure and risk assessment associated with mercury contamination in artisanal gold mining areas in the Brazilian Amazon. Environmental Science and Pollution Research. 2015;22:11255-11264.

    Not in our library10.1007/s11356-015-4340-y

  51. 51.

    Cesário R, Poissant L, Pilote M, O’Driscoll NJ, Mota AM, Canário J. Dissolved gaseous mercury formation and mercury volatilization in intertidal sediments. Science of the Total Environment. 2017;603–604:279-289.

    Not in our library10.1016/j.scitotenv.2017.06.093

  52. 52.

    Chalmers AT, Krabbenhoft DP, Van Metre PC, Nilles MA. Effects of urbanization on mercury deposition and New England. Environmental Pollution. 2014;192:104-112.

    Not in our library10.1016/j.envpol.2014.05.003

  53. 53.

    Chen CY, Folt CL. High plankton densities reduce mercury biomagnification. Environmental Science and Technology. 2005;39:115-121.

    Not in our library10.1021/es0403007

  54. 54.

    Chen CY, Driscoll CT, Kamman NC. Mercury hotspots in freshwater ecosystems. Mercury in the Environment: Pattern and Process. 2012;143:340.

    Not in our library

  55. 55.

    Christensen GA, Wymore AM, King AJ, Podar M, Hurt RA, Santillan EU, Soren A, Brandt CC, et al. Development and validation of broad-range qualitative and clade-specific quantitative molecular probes for assessing mercury methylation in the environment. Applied and Environmental Microbiology. 2016;82:6068-6078.

    Not in our library10.1128/aem.01271-16

  56. 56.

    Clark HF, Benoit G. Legacy sources of mercury in an urbanised watershed. Environmental Chemistry. 2009;6:235-244.

    Not in our library10.1071/en09006

  57. 57.

    Clarkson TW, Vyas JB, Ballatori N. Mechanisms of mercury disposition in the body. American Journal of Industrial Medicine. 2007;50:757-764.

    Not in our library10.1002/ajim.20476

  58. 58.

    Coleman Wasik JK, Mitchell CPJ, Engstrom DR, Swain EB, Monson BA, Balogh SJ, Jeremiason JD, Branfireun BA, et al. Methylmercury declines in a boreal peatland when experimental sulfate deposition decreases. Environmental Science & Technology. 2012;46:6663-6671.

    Not in our library10.1021/es300865f

  59. 59.

    Compeau GC, Bartha R. Sulfate-reducing bacteria: Principal methylators of mercury in anoxic estuarine sediment. Applied and Environmental Microbiology. 1985;50:498-502.

    Not in our library10.1128/aem.50.2.498-502.1985

  60. 60.

    Comte I, Lucotte M, Davidson R, de Carvalho CJR, Oliveira FD, Rousseau GX. Impacts of Land Uses on Mercury Retention in Long-Time Cultivated Soils. 2013;224.

    Not in our library

  61. 61.

    Cordy P, Veiga M, Bernaudat L, Garcia O. Successful airborne mercury reductions in Colombia. Journal of Cleaner Production. 2015;108(Part A):992-1001.

    Not in our library10.1016/j.jclepro.2015.06.102

  62. 62.

    Craig PJ, Moreton PA. The role of sulfide in the formation of dimethyl mercury in river and estuary sediments. Marine Pollution Bulletin. 1984;15:406-408.

    Not in our library10.1016/0025-326x(84)90257-1

  63. 63.

    de Wit HA, Granhus A, Lindholm M, Kainz MJ, Lin Y, Braaten HFV, Blaszczak J. Forest harvest effects on mercury in streams and biota in Norwegian boreal catchments. Forest Ecology and Management. 2014;324:52-63.

    Not in our library10.1016/j.foreco.2014.03.044

  64. 64.

    Deonarine A, Hsu-Kim H. Precipitation of mercuric sulfide nanoparticles in NOM-containing water: Implications for the natural environment. Environmental Science and Technology. 2009;43:2368-2373.

    Not in our library10.1021/es803130h

  65. 65.

    Deonarine A, Lau BLT, Aiken GR, Ryan JN, Hsu-Kim H. Effects of humic substances on precipitation and aggregation of zinc sulfide nanoparticles. Environmental Science and Technology. 2011;45:3217-3223.

    Not in our library10.1021/es1029798

  66. 66.

    Deonarine A, Bartov G, Johnson TM, Ruhl L, Vengosh A, Hsu-Kim H. Environmental impacts of the Tennessee Valley Authority Kingston Coal Ash Spill. 2. Effect of coal ash on methylmercury in historically contaminated river sediments. Environmental Science and Technology. 2013;47:2100-2108.

    Not in our library10.1021/es303639d

  67. 67.

    Deonarine A, Hsu-Kim H, Zhang T, Cai Y, Richardson CJ. Legacy source of mercury in an urban stream-wetland ecosystem in central North Carolina, USA. Chemosphere. 2015;138:960-965.

    Not in our library10.1016/j.chemosphere.2014.12.038

  68. 68.

    Desrosiers M, Planas D, Mucci A. Short-term responses to watershed logging on biomass mercury and methylmercury accumulation by periphyton in boreal lakes. Canadian Journal of Fisheries and Aquatic Sciences. 2006;63:1734-1745.

    Not in our library10.1139/f06-077

  69. 69.

    Diamond ML, Gingrich SE, Fertuck K, McCarry BE, Stern GA, Billeck B, Grift B, Brooker D, et al. Evidence for organic film on an impervious urban surface: Characterization and potential teratogenic effects. Environmental Science and Technology. 2000;34:2900-2908.

    Not in our library10.1021/es9906406

  70. 70.

    Diringer SE, Feingold BJ, Ortiz EJ, Gallis JA, Araujo-Flores JM, Berky A, Pan WKY, Hsu-Kim H. River transport of mercury from artisanal and small-scale gold mining and risks for dietary mercury exposure in Madre de Dios, Peru. Environmental Science: Processes & Impacts. 2015;17:478-487.

    Not in our library10.1039/c4em00567h

  71. 71.

    Dittman JA, Shanley JB, Driscoll CT, Aiken GR, Chalmers AT, Towse JE. Ultraviolet absorbance as a proxy for total dissolved mercury in streams. Environmental Pollution. 2009;157:1953-1956.

    Not in our library10.1016/j.envpol.2009.01.031

  72. 72.

    Dittman JA, Shanley JB, Driscoll CT, Aiken GR, Chalmers AT, Towse JE, Selvendiran P. Mercury dynamics in relation to dissolved organic carbon concentration and quality during high flow events in three northeastern U.S. streams. Water Resources. 2010.

    Not in our library

  73. 73.

    Domagalski J, Majewski MS, Alpers CN, Eckley CS, Eagles-Smith CA, Schenk L, Wherry S. Comparison of mercury mass loading in streams to atmospheric deposition in watersheds of Western North America: Evidence for non-atmospheric mercury sources. Science of the Total Environment. 2016;568:638-650.

    Not in our library10.1016/j.scitotenv.2016.02.112

  74. 74.

    Driscoll CT, Blette V, Yan C, Schofield CL, Munson R, Holsapple J. The role of dissolved organic carbon in the chemistry and bioavailability of mercury in remote Adirondack lakes. Water, Air, and Soil pollution. 1995;80:499-508.

    Not in our library10.1007/bf01189700

  75. 75.

    Driscoll CT, Chen CY, Hammerschmidt CR, Mason RP, Gilmour CC, Sunderland EM, Greenfield BK, Buckman KL, et al. Nutrient supply and mercury dynamics in marine ecosystems: A conceptual model. Environmental Research. 2012;119:118-131.

    Not in our library10.1016/j.envres.2012.05.002

  76. 76.

    Driscoll CT, Mason RP, Chan HM, Jacob DJ, Pirrone N. Mercury as a global pollutant: Sources, pathways, and effects. Environmental Science and Technology. 2013;47:4967-4983.

    Not in our library10.1021/es305071v

  77. 77.

    Drott A, Lambertsson L, Björn E, Skyllberg U. Importance of dissolved neutral mercury sulfides for methyl mercury production in contaminated sediments. Environmental Science and Technology. 2007;41:2270-2276.

    Not in our library10.1021/es061724z

  78. 78.
  79. 79.

    Eckley CS, Branfireun B. Gaseous mercury emissions from urban surfaces: Controls and spatiotemporal trends. Applied Geochemistry. 2008;23:369-383.

    Not in our library10.1016/j.apgeochem.2007.12.008

  80. 80.

    Eckley CS, Branfireun B. Mercury mobilization in urban stormwater runoff. Science of the Total Environment. 2008;403:164-177.

    Not in our library10.1016/j.scitotenv.2008.05.021

  81. 81.

    Eckley CS, Branfireun B. Simulated rain events on an urban roadway to understand the dynamics of mercury mobilization in stormwater runoff. Water Research. 2009;43:3635-3646.

    Not in our library10.1016/j.watres.2009.05.022

  82. 82.

    Eckley CS, Hintelmann H. Determination of mercury methylation potentials in the water column of lakes across Canada. Science of the Total Environment. 2006;368:111-125.

    Not in our library10.1016/j.scitotenv.2005.09.042

  83. 83.

    Eckley CS, Gustin M, Marsik F, Miller MB. Measurement of surface mercury fluxes at active industrial gold mines in Nevada (USA). Science of the Total Environment. 2011;409:514-522.

    Not in our library10.1016/j.scitotenv.2010.10.024

  84. 84.

    Eckley CS, Gustin M, Miller MB, Marsik F. Scaling non-point-source mercury emissions from two active industrial gold mines: Influential variables and annual emission estimates. Environmental Science and Technology. 2011;45:392-399.

    Not in our library10.1021/es101820q

  85. 85.

    Eckley CS, Luxton TP, McKernan JL, Goetz J, Goulet J. Influence of reservoir water level fluctuations on sediment methylmercury concentrations downstream of the historical Black Butte mercury mine, OR. Applied Geochemistry. 2015;61:284-293.

    Not in our library10.1016/j.apgeochem.2015.06.011

  86. 86.

    Eckley CS, Tate MT, Lin C-J, Gustin M, Dent S, Eagles-Smith C, Lutz MA, Wickland KP, et al. Surface-airmercury fluxes across Western North America: A synthesis of spatial trends and controlling variables. Science of the Total Environment. 2016;568:651-665.

    Not in our library10.1016/j.scitotenv.2016.02.121

  87. 87.

    Eckley CS, Luxton TP, Goetz J, McKernan J. Water-level fluctuations influence sediment porewater chemistry and methylmercury production in a flood-control reservoir. Environmental Pollution. 2017;222:32-41.

    Not in our library10.1016/j.envpol.2017.01.010

  88. 88.

    Eklof K, Kraus A, Weyhenmeyer GA, Meili M, Bishop K. Forestry influence by stump harvest and site preparation on methylmercury, total mercury and other stream water chemistry parameters across a boreal landscape. Ecosystems. 2012;15:1308-1320.

    Not in our library10.1007/s10021-012-9586-3

  89. 89.

    Eklof K, Meili M, Akerblom S, von Bromssen C, Bishop K. Impact of stump harvest on run-off concentrations of total mercury and methylmercury. Forest Ecology and Management. 2013;290:83-94.

    Not in our library10.1016/j.foreco.2012.05.039

  90. 90.

    Eklof K, Schelker J, Sorensen R, Meili M, Laudon H, von Bromssen C, Bishop K. Impact of forestry on total and methyl-mercury in surface waters: Distinguishing effects of logging and site preparation. Environmental Science and Technology. 2014;48:4690-4698.

    Not in our library10.1021/es404879p

  91. 91.

    Eklof K, Lidskog R, Bishop K. Managing Swedish forestry’s impact on mercury in fish: Defining the impact and mitigation measures. Ambio. 2016;45:S163-S174.

    Not in our library10.1007/s13280-015-0752-7

  92. 92.

    FAO. 2002. Rice information, Vol. 3. Rome: Food and Agriculture Organization of the United Nations. http://www.fao.org/docrep/005/Y4347E/y4347e00.htm.

    Not in our library

  93. 93.

    FAO. 2013. Rice farming: Saving water through Alternate Wetting Drying (AWD) method. TECA (Technologies and practices for small agricultural producers). http://teca.fao.org/read/7939. Posted on 27 November 2013.

    Not in our library

  94. 94.

    Farella N, Lucotte M, Davidson R, Daigle S. Mercury release from deforested soils triggered by base cation enrichment. Science of the Total Environment. 2006;368:19-29.

    Not in our library10.1016/j.scitotenv.2006.04.025

  95. 95.

    Feng X, Li P, Qiu G, Wang S, Li G, Shang L, Meng B, Jiang H, et al. Human exposure to methylmercury through rice intake in mercury mining areas, Guizhou Province, China. Environmental Science and Technology. 2007;42:326-332.

    Not in our library10.1021/es071948x

  96. 96.

    Feng X, Jiang H, Qiu G, Yan H, Li G, Li Z. Geochemical processes of mercury in Wujiangdu and Dongfeng reservoirs, Guizhou, China. Environmental Pollution. 2009;157:2970-2984.

    Not in our library10.1016/j.envpol.2009.06.002

  97. 97.

    Flanders JR, Turner RR, Morrison T, Jensen R, Pizzuto J, Skalak K, Stahl R. Distribution, behavior, and transport of inorganic and methylmercury in a high gradient stream. Applied Geochemistry. 2010;25:1756-1769.

    Not in our library10.1016/j.apgeochem.2010.09.004

  98. 98.

    Fleck JA, Marvin-DiPasquale M, Eagles-Smith CA, Ackerman JT, Lutz MA, Tate M, Alpers CN, Hall BD, et al. Mercury and methylmercury in aquatic sediment across western North America. Science of the Total Environment. 2016;568:727-738.

    Not in our library10.1016/j.scitotenv.2016.03.044

  99. 99.

    Fleming EJ, Mack EE, Green PG, Nelson DC. Mercury methylation from unexpected sources: Molybdate-inhibited freshwater sediments and an iron-reducing bacterium. Applied and Environmental Microbiology. 2006;72:457-464.

    Not in our library10.1128/aem.72.1.457-464.2006

  100. 100.

    Fostier AH, Forti MC, Guimaraes JRD, Melfi AJ, Boulet R, Santo CME, Krug FJ. Mercury fluxes in a natural forested Amazonian catchment (Serra do Navio, Amapa State, Brazil). Science of the Total Environment. 2000;260:201-211.

    Not in our library10.1016/s0048-9697(00)00564-7

  101. 101.

    Foucher D, Ogrinc N, Hintelmann H. Tracing mercury contamination from the Idrija Mining Region (Slovenia) to the Gulf of Trieste using Hg isotope ratio measurements. Environmental Science and Technology. 2009;43:33-39.

    Not in our library10.1021/es801772b

  102. 102.

    Fu XW, Zhang H, Yu B, Wang X, Lin CJ, Feng XB. Observations of atmospheric mercury in China: A critical review. Atmospheric Chemistry and Physics. 2015;15:9455-9476.

    Not in our library10.5194/acp-15-9455-2015

  103. 103.

    Fulkerson M, Nnadi FN, Chasar LS. Characterizing dry deposition of mercury in urban runoff. Water, Air, and Soil pollution. 2007;185:21-32.

    Not in our library10.1007/s11270-007-9396-y

  104. 104.

    Gabriel MC, Williamson DG, Zhang H, Brooks S, Lindberg S. Diurnal and seasonal trends in total gaseous mercury flux from three urban ground surfaces. Atmospheric Environment. 2006;40:4269-4284.

    Not in our library10.1016/j.atmosenv.2006.04.004

  105. 105.

    Gamby RL, Hammerschmidt CR, Costello DM, Lamborg CH, Runkle JR. Deforestation and cultivation mobilize mercury from topsoil. Science of the Total Environment. 2015;532:467-473.

    Not in our library10.1016/j.scitotenv.2015.06.025

  106. 106.

    Gammons CH, Pape BL, Parker SR, Poulson SR, Blank CE. Geochemistry, water balance, and stable isotopes of a “clean” pit lake at an abandoned tungsten mine, Montana, USA. Applied Geochemistry. 2013;36:57-69.

    Not in our library10.1016/j.apgeochem.2013.06.011

  107. 107.

    Garcia E, Carignan R. Impact of wildfire and clear-cutting in the boreal forest on methyl mercury in zooplankton. Canadian Journal of Fisheries and Aquatic Sciences. 1999;56:339-345.

    Not in our library10.1139/f98-164

  108. 108.

    Garcia E, Carignan R. Mercury concentrations in northern pike (Esox lucius) from boreal lakes with logged, burned, or undisturbed catchments. Canadian Journal of Fisheries and Aquatic Sciences. 2000;57:129-135.

    Not in our library10.1139/f00-126

  109. 109.

    Gascón Díez E, Loizeau J-L, Cosio C, Bouchet S, Adatte T, Amouroux D, Bravo AG. Role of settling particles on mercury methylation in the oxic water column of freshwater systems. Environmental Science and Technology. 2016;50:11672-11679.

    Not in our library10.1021/acs.est.6b03260

  110. 110.

    Gerbig CA, Ryan JN, Aiken GR, Liu G, Cai Y, O’Driscoll NO. The effects of dissolved organic matter on mercury biogeochemistry. Environmental Chemistry and Toxicology of Mercury. 2012;259-292.

    Not in our library

  111. 111.

    Ghosh U, Luthy RG, Cornelissen G, Werner D, Menzie CA. In-situ sorbent amendments: A new direction in contaminated sediment management. Environmental Science and Technology. 2011;45:1163-1168.

    Not in our library10.1021/es102694h

  112. 112.
  113. 113.

    Gilmour CC, Henry EA, Mitchell R. Sulfate stimulation of mercury methylation in fresh-water sediments. Environmental Science and Technology. 1992;26:2281-2287.

    Not in our library10.1021/es00035a029

  114. 114.

    Gilmour CC, Podar M, Bullock AL, Graham AM, Brown SD, Somenahally AC, Johs A, Hurt RA, et al. Mercury methylation by novel microorganisms from new environments. Environmental Science and Technology. 2013;47:11810-11820.

    Not in our library10.1021/es403075t

  115. 115.

    Gilmour CC, Riedel GS, Riedel G, Kwon S, Landis R, Brown SS, Menzie CA, Ghosh U. Activated carbon mitigates mercury and methylmercury bioavailability in contaminated sediments. Environmental Science and Technology. 2013;47:13001-13010.

    Not in our library10.1021/es4021074

  116. 116.

    Gingrich SE, Diamond ML. Atmospherically derived organic surface films along an urban-rural gradient. Environmental Science and Technology. 2001;35:4031-4037.

    Not in our library10.1021/es010699o

  117. 117.

    Gionfriddo CM, Tate MT, Wick RR, Schultz MB, Zemla A, Thelen MP, Schofield R, Krabbenhoft DP, et al. Microbial mercury methylation in Antarctic sea ice. Nature microbiology. 2016;1:16127.

    Not in our library10.1038/nmicrobiol.2016.127

  118. 118.

    Gomez-Eyles JL, Yupanqui C, Beckingham B, Riedel G, Gilmour C, Ghosh U. Evaluation of biochars and activated carbons for in situ remediation of sediments impacted with organics, mercury, and methylmercury. Environmental Science and Technology. 2013;47:13721-13729.

    Not in our library10.1021/es403712q

  119. 119.

    Gosnell KJ, Balcom PH, Tobias CR, Gilhooly WP, Mason RP. Spatial and temporal trophic transfer dynamics of mercury and methylmercury into zooplankton and phytoplankton of Long Island Sound. Limnology and Oceanography. 2017;62:1122-1138.

    Not in our library10.1002/lno.10490

  120. 120.

    Graham AM, Aiken GR, Gilmour CC. Dissolved organic matter enhances microbial mercury methylation under sulfidic conditions. Environmental Science and Technology. 2012;46:2715-2723.

    Not in our library10.1021/es203658f

  121. 121.

    Grandjean P, White RF, Nielsen A, Cleary D, de Oliveira Santos EC. Methylmercury neurotoxicity in Amazonian children downstream from gold mining. Environmental Health Perspectives. 1999;107:587-591.

    Not in our library10.1289/ehp.99107587

  122. 122.

    Graydon JA, St Louis VL, Lindberg SE, Sandilands KA, Rudd JW, Kelly CA, Harris R, Tate MT, et al. The role of terrestrial vegetation in atmospheric Hg deposition: Pools and fluxes of spike and ambient Hg from the METAALICUS experiment. Global Biogeochemical Cycles. 2012;26:GB1022.

    Not in our library10.1029/2011gb004031

  123. 123.

    Grimaldi M, Guédron S, Grimaldi C, Brearley FQ, Thomas AD. Impact of gold mining on mercury contamination and soil degradation in Amazonian ecosystems of French Guiana. Land-use change impacts on soil processes: Tropical and savannah ecosystems. 2015;95-107.

    Not in our library

  124. 124.

    Guimaraes JRD, Betancourt O, Miranda MR, Barriga R, Cueva E, Betancourt S. Long-range effect of cyanide on mercury methylation in a gold mining area in southern Ecuador. Science of the Total Environment. 2011;409:5026-5033.

    Not in our library10.1016/j.scitotenv.2011.08.021

  125. 125.

    Hagan N, Robins N, Hsu-Kim H, Halabi S, Espinoza Gonzales RD, Richter D, Vandenberg J. Residential mercury contamination in adobe brick homes in Huancavelica, Peru. PLOS ONE. 2013;8:e75179.

    Not in our library10.1371/journal.pone.0075179

  126. 126.

    Hagan N, Robins N, Hsu-Kim H, Halabi S, Espinoza Gonzales RD, Ecos E, Richter D, Vandenberg J. Mercury hair levels and factors that influence exposure for residents of Huancavelica, Peru. Environmental Geochemistry and Health. 2015;37:507-514.

    Not in our library10.1007/s10653-014-9665-9

  127. 127.

    Hall BD, Louis VLS. Methylmercury and total mercury in plant litter decomposing in upland forests and flooded landscapes. Environmental Science and Technology. 2004;38:5010-5021.

    Not in our library10.1021/es049800q

  128. 128.

    Hall BD, St Louis VL, Bodaly RA. The stimulation of methylmercury production by decomposition of flooded birch leaves and jack pine needles. Biogeochemistry. 2004;68:107-129.

    Not in our library10.1023/b:biog.0000025745.28447.8b

  129. 129.

    Hall BD, Cherewyk KA, Paterson MJ, Bodaly RA. Changes in methyl mercury concentrations in zooplankton from four experimental reservoirs with differing amounts of carbon in the flooded catchments This paper is part of the series “Forty Years of Aquatic Research at the Experimental Lakes Area”. Canadian Journal of Fisheries and Aquatic Sciences. 2009;66:1910-1919.

    Not in our library10.1139/f09-123

  130. 130.

    Hamelin S, Planas D, Amyot M. Mercury methylation and demethylation by periphyton biofilms and their host in a fluvial wetland of the St. Lawrence River (QC, Canada). Science of the Total Environment. 2015;512:464-471.

    Not in our library10.1016/j.scitotenv.2015.01.040

  131. 131.

    Hammerschmidt CR, Fitzgerald WF. Photodecomposition of methylmercury in an arctic Alaskan lake. Environmental Science and Technology. 2006;40:1212-1216.

    Not in our library10.1021/es0513234

  132. 132.

    Hammerschmidt CR, Fitzgerald WF. Iron-mediated photochemical decomposition of methylmercury in an Arctic Alaskan lake. Environmental Science and Technology. 2010;44:6138-6143.

    Not in our library10.1021/es1006934

  133. 133.

    Han S, Gill GA. Determination of mercury complexation in coastal and estuarine waters using competitive ligand exchange method. Environmental Science and Technology. 2005;39:6607-6615.

    Not in our library10.1021/es048667z

  134. 134.

    Harris RC, Rudd JWM, Amyot M, Babiarz CL, Beaty KG, Blanchfield PJ, Bodaly RA, Branfireun BA, et al. Whole-ecosystem study shows rapid fish-mercury response to changes in mercury deposition. Proceedings of the National academy of Sciences of the United States of America. 2007;104:16586-16591.

    Not in our library10.1073/pnas.0704186104

  135. 135.

    He T, Feng X, Guo Y, Qiu G, Li Z, Liang L, Lu J. The impact of eutrophication on the biogeochemical cycling of mercury species in a reservoir: a case study from Hongfeng Reservoir, Guizhou, China. Environmental Pollution. 2008;154:56-67.

    Not in our library10.1016/j.envpol.2007.11.013

  136. 136.

    Herrin RT, Lathrop RC, Gorski PR, Andren AW. Hypolimnetic methylmercury and its uptake by plankton during fall destratification: A key entry point of mercury into lake food chains? Limnology and Oceanography. 1998;43:1476-1486.

    Not in our library10.4319/lo.1998.43.7.1476

  137. 137.

    Hidayati N, Juhaeti T, Syarif F. Mercury and cyanide contaminations in gold mine environment and possible solution of cleaning up by using phytoextraction. HAYATI Journal of Biosciences. 2009;16:88-94.

    Not in our library10.4308/hjb.16.3.88

  138. 138.

    Hines ME, Faganeli J, Adatto I, Horvat M. Microbial mercury transformations in marine, estuarine and freshwater sediment downstream of the Idrija Mercury Mine, Slovenia. Applied Geochemistry. 2006;21:1924-1939.

    Not in our library10.1016/j.apgeochem.2006.08.008

  139. 139.

    Hines ME, Poitras EN, Covelli S, Faganeli J, Emili A, Žižek S, Horvat M. Mercury methylation and demethylation in Hg-contaminated lagoon sediments (Marano and Grado Lagoon, Italy). Estuarine, Coastal and Shelf Science. 2012;113:85-95.

    Not in our library10.1016/j.ecss.2011.12.021

  140. 140.

    Hintelmann H, Harris R, Heyes A, Hurley JP, Kelly CA, Krabbenhoft DP, Lindberg S, Rudd JWM, et al. Reactivity and mobility of new and old mercury deposition in a boreal forest ecosystem during the first year of the METAALICUS Study. Environmental Science and Technology. 2002;36:5034-5040.

    Not in our library10.1021/es025572t

  141. 141.

    Horvat M, Nolde N, Fajon V, Jereb V, Logar M, Lojen S, Jacimovic R, Falnoga I, et al. Total mercury, methylmercury and selenium in mercury polluted areas in the province Guizhou, China. Science of the Total Environment. 2003;304:231-256.

    Not in our library10.1016/s0048-9697(02)00572-7

  142. 142.

    Hrabik T, Watras C. Recent declines in mercury concentration in a freshwater fishery: isolating the effects of de-acidification and decreased atmospheric mercury deposition in Little Rock Lake. Science of the Total Environment. 2002;297:229-237.

    Not in our library10.1016/s0048-9697(02)00138-9

  143. 143.

    Hsu-Kim H, Sedlak DL. Similarities between inorganic sulfide and the strong Hg(II)-complexing ligands in municipal wastewater effluent. Environmental Science and Technology. 2005;39:4035-4041.

    Not in our library10.1021/es050013i

  144. 144.

    Hsu-Kim H, Kucharzyk KH, Zhang T, Deshusses MA. Mechanisms regulating mercury bioavailability for methylating microorganisms in the aquatic environment: A critical review. Environmental Science and Technology. 2013;47:2441-2456.

    Not in our library10.1021/es304370g

  145. 145.

    Huang MJ, Wang W, Leung HM, Chan CY, Liu WK, Wong MH, Cheung KC. Mercury levels in road dust and household TSP/PM2.5 related to concentrations in hair in Guangzhou, China. Ecotoxicology and Environmental Safety. 2012;81:27-35.

    Not in our library10.1016/j.ecoenv.2012.04.010

  146. 146.

    Hurley JP, Cowell SE, Shafer MM, Hughes PE. Tributary loading of mercury to Lake Michigan: Importance of seasonal events and phase partitioning. Science of the Total Environment. 1998;213:129-137.

    Not in our library10.1016/s0048-9697(98)00084-9

  147. 147.

    Jang YC, Jain P, Tolaymat T, Dubey B, Singh S, Townsend T. Characterization of roadway stormwater system residuals for reuse and disposal options. Science of the Total Environment. 2010;408:1878-1887.

    Not in our library10.1016/j.scitotenv.2010.01.036

  148. 148.

    Jeremiason JD, Engstrom DR, Swain EB, Nater EA, Johnson BM, Almendinger JE, Monson BA, Kolka RK. Sulfate addition increases methylmercury production in an experimental wetland. Environmental Science and Technology. 2006;40:3800-3806.

    Not in our library10.1021/es0524144

  149. 149.

    Jimenez-Moreno M, Barre JPG, Perrot V, Berail S, Martin-Doimeadios RCR, Amouroux D. Sources and fate of mercury pollution in Almaden mining district (Spain): Evidences from mercury isotopic compositions in sediments and lichens. Chemosphere. 2016;147:430-438.

    Not in our library10.1016/j.chemosphere.2015.12.094

  150. 150.

    Johnson NW, Reible DD, Katz LE. Biogeochemical changes and mercury methylation beneath an in-situ sediment cap. Environmental Science and Technology. 2010;44:7280-7286.

    Not in our library10.1021/es100161p

  151. 151.

    Johnston TA, Bodaly R, Mathias J. Predicting fish mercury levels from physical characteristics of boreal reservoirs. Canadian Journal of Fisheries and Aquatic Sciences. 1991;48:1468-1475.

    Not in our library10.1139/f91-174

  152. 152.

    Jonsson S, Skyllberg U, Nilsson MB, Westlund P-O, Shchukarev A, Lundberg E, Björn E. Mercury methylation rates for geochemically relevant HgII species in sediments. Environmental Science and Technology. 2012;46:11653-11659.

    Not in our library10.1021/es3015327

  153. 153.

    Jonsson S, Skyllberg U, Nilsson MB, Lundberg E, Andersson A, Björn E. Differentiated availability of geochemical mercury pools controls methylmercury levels in estuarine sediment and biota. Nature Communications. 2014;5:4624.

    Not in our library10.1038/ncomms5624

  154. 154.

    Jonsson S, Mazrui NM, Mason RP. Dimethylmercury formation mediated by inorganic and organic reduced sulfur surfaces. Scientific Reports. 2016;6:27958.

    Not in our library10.1038/srep27958

  155. 155.

    Jonsson S, Andersson A, Nilsson MB, Skyllberg U, Lundberg E, Schaefer JK, Åkerblom S, Björn E. Terrestrial discharges mediate trophic shifts and enhance methylmercury accumulation in estuarine biota. Science Advances. 2017;3:e1601239.

    Not in our library10.1126/sciadv.1601239

  156. 156.

    Kajiwara Y, Yasutake A, Adachi T, Hirayama K. Methylmercury transport across the placenta via neutral amino acid carrier. Archives of Toxicology. 1996;70:310-314.

    Not in our library10.1007/s002040050279

  157. 157.

    Kamman NC, Burgess NM, Driscoll CT, Simonin HA, Goodale W, Linehan J, Estabrook R, Hutcheson M, et al. Mercury in freshwater fish of northeast North America—A geographic perspective based on fish tissue monitoring databases. Ecotoxicology. 2005;14:163-180.

    Not in our library10.1007/s10646-004-6267-9

  158. 158.

    Kelly CA, Rudd JWM, Bodaly RA, Roulet NP, StLouis VL, Heyes A, Moore TR, Schiff S, et al. Increases in fluxes of greenhouse gases and methyl mercury following flooding of an experimental reservoir. Environmental Science and Technology. 1997;31:1334-1344.

    Not in our library10.1021/es9604931

  159. 159.

    Kerin EJ, Gilmour CC, Roden E, Suzuki MT, Coates JD, Mason RP. Mercury methylation by dissimilatory iron-reducing bacteria. Applied and Environmental Microbiology. 2006;72:7919-7921.

    Not in our library10.1128/aem.01602-06

  160. 160.

    Kerper LE, Ballatori N, Clarkson TW. Methylmercury transport across the blood–brain barrier by an amino acid carrier. American Journal of Physiology—Regulatory, Integrative and Comparative Physiology. 1992;262:R761-R765.

    Not in our library10.1152/ajpregu.1992.262.5.r761

  161. 161.

    Kim E, Mason RP, Bergeron CM. A modeling study on methylmercury bioaccumulation and its controlling factors. Ecological Modelling. 2008;218:267-289.

    Not in our library10.1016/j.ecolmodel.2008.07.008

  162. 162.

    Kim SH, Han YJ, Holsen TM, Yi SM. Characteristics of atmospheric speciated mercury concentrations (TGM, Hg(II) and Hg(p)) in Seoul, Korea. Atmospheric Environment. 2009;43:3267-3274.

    Not in our library10.1016/j.atmosenv.2009.02.038

  163. 163.

    Kim M, Han S, Gieskes J, Deheyn DD. Importance of organic matter lability for monomethylmercury production in sulfate-rich marine sediments. Science of the Total Environment. 2011;409:778-784.

    Not in our library10.1016/j.scitotenv.2010.10.050

  164. 164.

    King JK, Kostka JE, Frischer ME, Saunders FM. Sulfate-reducing bacteria methylate mercury at variable rates in pure culture and in marine sediments. Applied and Environmental Microbiology. 2000;66:2430-2437.

    Not in our library10.1128/aem.66.6.2430-2437.2000

  165. 165.

    King JK, Harmon SM, Fu TT, Gladden JB. Mercury removal, methylmercury formation, and sulfate-reducing bacteria profiles in wetland mesocosms. Chemosphere. 2002;46:859-870.

    Not in our library10.1016/s0045-6535(01)00135-7

  166. 166.

    Klapstein SJ, Ziegler SE, Risk DA, O’Driscoll NJ. Quantifying the effects of photoreactive dissolved organic matter on methylmercury photodemethylation rates in freshwaters. Environmental Toxicology and Chemistry. 2017;36:1493-1502.

    Not in our library10.1002/etc.3690

  167. 167.

    Køster-Rasmussen R, Westergaard ML, Brasholt M, Gutierrez R, Jørs E, Thomsen JF. Mercury pollution from small-scale gold mining can be stopped by implementing the gravity-borax method—A two-year follow-up study from two mining communities in the philippines. NEW SOLUTIONS: A Journal of Environmental and Occupational Health Policy. 2016;25:567-587.

    Not in our library10.1177/1048291115607929

  168. 168.

    Krisnayanti, B.D., C.W.N. Anderson, W.H. Utomo, X. Feng, E. Handayanto, N. Mudarisna, H. Ikram, and Khususiah. 2012. Assessment of environmental mercury discharge at a four-year-old artisanal gold mining area on Lombok Island, Indonesia. Journal of Environmental Monitoring 14:2598–2607.

    Not in our library10.1039/c2em30515a

  169. 169.

    Kristensen AKB, Thomsen JF, Mikkelsen S. A review of mercury exposure among artisanal small-scale gold miners in developing countries. International Archives of Occupational and Environmental Health. 2014;87:579-590.

    Not in our library10.1007/s00420-013-0902-9

  170. 170.

    Kronberg R-M, Jiskra M, Wiederhold JG, Bjorn E, Skyllberg U. Methyl mercury formation in hillslope soils of boreal forests: The role of forest harvest and anaerobic microbes. Environmental Science and Technology. 2016;50:9177-9186.

    Not in our library10.1021/acs.est.6b00762

  171. 171.

    Kronberg RM, Drott A, Jiskra M, Wiederhold JG, Bjorn E, Skyllberg U. Forest harvest contribution to Boreal freshwater methyl mercury load. Global Biogeochemical Cycles. 2016;30:825-843.

    Not in our library10.1002/2015gb005316

  172. 172.

    Kucharzyk KH, Deshusses MA, Porter KA, Hsu-Kim H. Relative contributions of mercury bioavailability and microbial growth rate on net methylmercury production by anaerobic mixed cultures. Environmental Science: Processes & Impacts. 2015;17:1568-1577.

    Not in our library10.1039/c5em00174a

  173. 173.

    Lacerda LD. Updating global Hg emissions from small-scale gold mining and assessing its environmental impacts. Environmental Geology. 2003;43:308-314.

    Not in our library

  174. 174.

    Lacerda LD, Bastos WR, Almeida MD. The impacts of land use changes in the mercury flux in the Madeira River, Western Amazon. Anais Da Academia Brasileira De Ciencias. 2012;84:69-78.

    Not in our library10.1590/s0001-37652012000100007

  175. 175.

    Lakel WA, Aust WM, Bolding MC, Dolloff CA, Keyser P, Feldt R. Sediment trapping by streamside management zones of various widths after forest harvest and site preparation. Forest Science. 2010;56:541-551.

    Not in our library

  176. 176.

    Lamborg C, Bowman K, Hammerschmidt C, Gilmour C, Munson K, Selin N, Tseng C-M. Mercury in the Anthropocene Ocean. Oceanography. 2014;27:76-87.

    Not in our library10.5670/oceanog.2014.11

  177. 177.

    Larssen T. Mercury in Chinese reservoirs. Environmental Pollution. 2010;158:24-25.

    Not in our library10.1016/j.envpol.2009.07.026

  178. 178.

    Lawson NM, Mason RP, Laporte JM. The fate and transport of mercury, methylmercury, and other trace metals in Chesapeake Bay tributaries. Water Research. 2001;35:501-515.

    Not in our library10.1016/s0043-1354(00)00267-0

  179. 179.

    Lebel J, Roulet M, Mergler D, Lucotte M, Larribe F. Fish diet and mercury exposure in a riparian amazonian population. Water, Air, and Soil pollution. 1997;97:31-44.

    Not in our library

  180. 180.

    Lehnherr I, St. Louis. VL. Importance of ultraviolet radiation in the photodemethylation of methylmercury in freshwater ecosystems. Environmental Science and Technology. 2009;43:5692-5698.

    Not in our library10.1021/es9002923

  181. 181.

    Lehnherr I, Louis VLS, Hintelmann H, Kirk JL. Methylation of inorganic mercury in polar marine waters. Nature Geoscience. 2011;4:298-302.

    Not in our library10.1038/ngeo1134

  182. 182.

    Lepak JM, Kinzli KD, Fetherman ER, Pate WM, Hansen AG, Gardunio EI, Cathcart CN, Stacy WL, et al. Manipulation of growth to reduce mercury concentrations in sport fish on a whole-system scale. Canadian Journal of Fisheries and Aquatic Sciences. 2012;69:122-135.

    Not in our library10.1139/f2011-136

  183. 183.

    Li P, Feng XB, Qiu GL, Shang LH, Li ZG. Mercury pollution in Asia: A review of the contaminated sites. Journal of Hazardous Materials. 2009;168:591-601.

    Not in our library10.1016/j.jhazmat.2009.03.031

  184. 184.

    Li L, Wang F, Meng B, Lemes M, Feng X, Jiang G. Speciation of methylmercury in rice grown from a mercury mining area. Environmental Pollution. 2010;158:3103-3107.

    Not in our library10.1016/j.envpol.2010.06.028

  185. 185.

    Li P, Feng X, Yuan X, Chan HM, Qiu G, Sun G-X, Zhu Y-G. Rice consumption contributes to low level methylmercury exposure in southern China. Environment International. 2012;49:18-23.

    Not in our library10.1016/j.envint.2012.08.006

  186. 186.

    Li B, Shi J, Wang X, Meng M, Huang L, Qi X, He B, Ye Z. Variations and constancy of mercury and methylmercury accumulation in rice grown at contaminated paddy field sites in three Provinces of China. Environmental Pollution. 2013;181:91-97.

    Not in our library10.1016/j.envpol.2013.06.021

  187. 187.

    Li Z, Ma Z, van der Kuijp TJ, Yuan Z, Huang L. A review of soil heavy metal pollution from mines in China: Pollution and health risk assessment. Science of the Total Environment. 2014;468–469:843-853.

    Not in our library10.1016/j.scitotenv.2013.08.090

  188. 188.

    Li J, Zhou Q, Yuan G, He X, Xie P. Mercury bioaccumulation in the food web of Three Gorges Reservoir (China): Tempo-spatial patterns and effect of reservoir management. Science of the Total Environment. 2015;527:203-210.

    Not in our library10.1016/j.scitotenv.2015.04.115

  189. 189.

    Li P, Feng X, Chan H-M, Zhang X, Du B. Human body burden and dietary methylmercury intake: The relationship in a rice-consuming population. Environmental Science and Technology. 2015;49:9682-9689.

    Not in our library10.1021/acs.est.5b00195

  190. 190.

    Liang L, Horvat M, Alvarez J, Young L, Kotnik J, Zhang L. The challenge and its solution when determining biogeochemically reactive inorganic mercury (RHg): Getting the analytical method right. American Journal of Analytical Chemistry. 2013;4(11):623-632.

    Not in our library10.4236/ajac.2013.411074

  191. 191.

    Liang P, Feng X, Zhang C, Zhang J, Cao Y, You Q, Leung AOW, Wong M-H, et al. Human exposure to mercury in a compact fluorescent lamp manufacturing area: By food (rice and fish) consumption and occupational exposure. Environmental Pollution. 2015;198:126-132.

    Not in our library10.1016/j.envpol.2014.12.036

  192. 192.

    Liem-Nguyen V, Jonsson S, Skyllberg U, Nilsson MB, Andersson A, Lundberg E, Björn E. Effects of nutrient loading and mercury chemical speciation on the formation and degradation of methylmercury in estuarine sediment. Environmental Science and Technology. 2016;50:6983-6990.

    Not in our library10.1021/acs.est.6b01567

  193. 193.

    Lindberg S, Bullock R, Ebinghaus R, Engstrom D, Feng X, Fitzgerald W, Pirrone N, Prestbo E, et al. A synthesis of progress and uncertainties in attributing the sources of mercury in deposition. Ambio. 2007;36:19-32.

    Not in our library10.1579/0044-7447(2007)36[19:asopau]2.0.co;2

  194. 194.

    Lindeström L. Mercury in sediment and fish communities of Lake Vänern, Sweden: Recovery from contamination. Ambio. 2001;30:538-544.

    Not in our library10.1579/0044-7447-30.8.538

  195. 195.

    Liu J, Feng X, Yin R, Zhu W, Li Z. Mercury distributions and mercury isotope signatures in sediments of Dongjiang, the Pearl River Delta, China. Chemical Geology. 2011;287:81-89.

    Not in our library10.1016/j.chemgeo.2011.06.001

  196. 196.

    Liu B, Yan H, Wang C, Li Q, Guédron S, Spangenberg JE, Feng X, Dominik J. Insights into low fish mercury bioaccumulation in a mercury-contaminated reservoir, Guizhou, China. Environmental Pollution. 2012;160:109-117.

    Not in our library10.1016/j.envpol.2011.09.023

  197. 197.

    Liu G, Cai Y, O’Driscoll N. Environmental Chemistry and Toxicology of Mercury. 2012.

    Not in our library

  198. 198.

    Liu G, Li Y, Cai Y, Liu G, Cai Y, O’Driscoll N. Adsorption of mercury on solids in the aquatic environment. Environmental Chemistry and Toxicology of Mercury. 2012;367-387.

    Not in our library

  199. 199.

    Liu ZF, He CY, Zhou YY, Wu JG. How much of the world’s land has been urbanized, really? A hierarchical framework for avoiding confusion. Landscape Ecology. 2014;29:763-771.

    Not in our library10.1007/s10980-014-0034-y

  200. 200.

    Lobo FDL, Costa MPF, de Moraes Novo EML, Telmer K. Distribution of artisanal and small-scale gold mining in the Tapajós River Basin (Brazilian Amazon) over the past 40 years and relationship with water siltation. Remote Sensing. 2016;8:579.

    Not in our library10.3390/rs8070579

  201. 201.

    Lockhart WL, Stern GA, Low G, Hendzel M, Boila G, Roach P, Evans MS, Billeck BN, et al. A history of total mercury in edible muscle of fish from lakes in northern Canada. Science of the Total Environment. 2005;351–352:427-463.

    Not in our library10.1016/j.scitotenv.2004.11.027

  202. 202.

    Louie SM, Spielman-Sun ER, Small MJ, Tilton RD, Lowry GV. Correlation of the physicochemical properties of natural organic matter samples from different sources to their effects on gold nanoparticle aggregation in monovalent electrolyte. Environmental Science and Technology. 2015;49:2188-2198.

    Not in our library10.1021/es505003d

  203. 203.

    Louie SM, Tilton RD, Lowry GV. Critical review: Impacts of macromolecular coatings on critical physicochemical processes controlling environmental fate of nanomaterials. Environmental Science: Nano. 2016;3:283-310.

    Not in our library

  204. 204.

    Louis VL, Kelly CA, Duchemin É, Rudd JW, Rosenberg DM. Reservoir surfaces as sources of greenhouse gases to the atmosphere: A global estimate: reservoirs are sources of greenhouse gases to the atmosphere, and their surface areas have increased to the point where they should be included in global inventories of anthropogenic emissions of greenhouse gases. BioScience. 2000;50:766-775.

    Not in our library10.1641/0006-3568(2000)050[0766:rsasog]2.0.co;2

  205. 205.

    Lucotte, M., L. Campbell, M. Clayden, C. Eckley, R. Harris, M. Kelly, K. Kidd, D. Lean, et al. 2012. Influences of anthropogenic activities on mercury transport, methylation and bioaccumulation. In Canadian Mercury Science Assessment. Sainte-Foy: Environment Canada.

    Not in our library

  206. 206.

    Lucotte M, Paquet S, Moingt M. Climate and physiography predict mercury concentrations in game fish species in Quebec Lakes better than anthropogenic disturbances. Archives of Environmental Contamination and Toxicology. 2016;70:710-723.

    Not in our library10.1007/s00244-016-0261-0

  207. 207.

    Luengen AC, Flegal AR. Role of phytoplankton in mercury cycling in the San Francisco Bay estuary. Limnology and Oceanography. 2009;54:23-40.

    Not in our library10.4319/lo.2009.54.1.0023

  208. 208.

    Lyons WB, Fitzgibbon TO, Welch KA, Carey AE. Mercury geochemistry of the Scioto River, Ohio: Impact of agriculture and urbanization. Applied Geochemistry. 2006;21:1880-1888.

    Not in our library10.1016/j.apgeochem.2006.08.005

  209. 209.

    Mailman M, Bodaly RD. The burning question: Does burning before flooding lower methyl mercury production and bioaccumulation? Science of the Total Environment. 2006;368:407-417.

    Not in our library10.1016/j.scitotenv.2005.09.070

  210. 210.

    Mailman M, Stepnuk L, Cicek N, Bodaly RA. Strategies to lower methyl mercury concentrations in hydroelectric reservoirs and lakes: A review. Science of the Total Environment. 2006;368:224-235.

    Not in our library10.1016/j.scitotenv.2005.09.041

  211. 211.

    Mainville N, Webb J, Lucotte M, Davidson R, Betancourt O, Cueva E, Mergler D. Decrease of soil fertility and release of mercury following deforestation in the Andean Amazon, Napo River Valley, Ecuador. Science of the Total Environment. 2006;368:88-98.

    Not in our library10.1016/j.scitotenv.2005.09.064

  212. 212.

    Malm O. Gold mining as a source of mercury exposure in the Brazilian Amazon. Environmental Research. 1998;77:73-78.

    Not in our library10.1006/enrs.1998.3828

  213. 213.

    Malm O, Castro MB, Bastos WR, Branches FJP, Guimarães JRD, Zuffo CE, Pfeiffer WC. An assessment of Hg pollution in different goldmining areas, Amazon Brazil. Science of the Total Environment. 1995;175:127-140.

    Not in our library10.1016/0048-9697(95)04909-6

  214. 214.

    Manta DS, Angelone M, Bellanca A, Neri R, Sprovieri M. Heavy metals in urban soils: A case study from the city of Palermo (Sicily), Italy. Science of the Total Environment. 2002;300:229-243.

    Not in our library10.1016/s0048-9697(02)00273-5

  215. 215.

    Marvin-DiPasquale M, Lutz MA, Brigham ME, Krabbenhoft DP, Aiken GR, Orem WH, Hall BD. Mercury cycling in stream ecosystems. 2. Benthic methylmercury production and bed sediment-pore water partitioning. Environmental Science and Technology. 2009;43:2726-2732.

    Not in our library10.1021/es802698v

  216. 216.

    Mason RP, Sullivan KA. Mercury and methylmercury transport through an urban watershed. Water Research. 1998;32:321-330.

    Not in our library10.1016/s0043-1354(97)00285-6

  217. 217.

    Mason RP, Lawson NM, Sullivan KA. Atmospheric deposition to the Chesapeake Bay watershed—Regional and local sources. Atmospheric Environment. 1997;31:3531-3540.

    Not in our library10.1016/s1352-2310(97)00207-0

  218. 218.

    Matthews DA, Babcock DB, Nolan JG, Prestigiacomo AR, Effler SW, Driscoll CT, Todorova SG, Kuhr KM. Whole-lake nitrate addition for control of methylmercury in mercury-contaminated Onondaga Lake, NY. Environmental Research. 2013;125:52-60.

    Not in our library10.1016/j.envres.2013.03.011

  219. 219.

    Maurice-Bourgoin L, Quiroga I, Chincheros J, Courau P. Mercury distribution in waters and fishes of the upper Madeira rivers and mercury exposure in riparian Amazonian populations. Science of the Total Environment. 2000;260:73-86.

    Not in our library10.1016/s0048-9697(00)00542-8

  220. 220.

    Mauro JB, Guimarães JR, Melamed R. Mercury methylation in macrophyte roots of a tropical lake. Water, Air, and Soil pollution. 2001;127:271-280.

    Not in our library10.1023/a:1005222902966

  221. 221.

    May, J. T., R. L. Hothem, C. N. Alpers, and M. A. Law. 2000. Mercury bioaccumulation in fish in a region affected by historic gold mining: The South Yuba River, Deer Creek, and Bear River watersheds, California, 1999.

    Not in our library

  222. 222.

    Mazrui NM, Jonsson S, Thota S, Zhao J, Mason RP. Enhanced availability of mercury bound to dissolved organic matter for methylation in marine sediments. Geochimica et Cosmochimica Acta. 2016;194:153-162.

    Not in our library10.1016/j.gca.2016.08.019

  223. 223.

    Mazur M, Mitchell CPJ, Eckley CS, Eggert SL, Kolka RK, Sebestyen SD, Swain EB. Gaseous mercury fluxes from forest soils in response to forest harvesting intensity: A field manipulation experiment. Science of the Total Environment. 2014;496:678-687.

    Not in our library10.1016/j.scitotenv.2014.06.058

  224. 224.

    McCord SA, Beutel MW, Dent SR, Schladow SG. Evaluation of mercury cycling and hypolimnetic oxygenation in mercury-impacted seasonally stratified reservoirs in the Guadalupe River watershed, California. Water Resources Research. 2016;52:7726-7743.

    Not in our library10.1002/2016wr019061

  225. 225.

    McKee LJ, Gilbreath AN. Concentrations and loads of suspended sediment and trace element pollutants in a small semi-arid urban tributary, San Francisco Bay, California. Environmental Monitoring and Assessment. 2015;187:499.

    Not in our library10.1007/s10661-015-4710-4

  226. 226.

    Mehrotra AS, Sedlak DL. Decrease in net mercury methylation rates following iron amendment to anoxic wetland sediment slurries. Environmental Science and Technology. 2005;39:2564-2570.

    Not in our library10.1021/es049096d

  227. 227.

    Meier J, Piva A, Fortin D. Enrichment of sulfate-reducing bacteria and resulting mineral formation in media mimicking pore water metal ion concentrations and pH conditions of acidic pit lakes. FEMS Microbiology Ecology. 2012;79:69-84.

    Not in our library10.1111/j.1574-6941.2011.01199.x

  228. 228.

    Meister JF, DiNunzio J, Cox JA. Source and level of mercury in a new impoundment. American Water Works Association. 1979;71:574-576.

    Not in our library

  229. 229.

    Meng B, Feng X, Qiu G, Cai Y, Wang D, Li P, Shang L, Sommar J. Distribution patterns of inorganic mercury and methylmercury in tissues of rice (Oryza sativa L.) plants and possible bioaccumulation pathways. Journal of Agricultural and Food Chemistry. 2010;58:4951-4958.

    Not in our library10.1021/jf904557x

  230. 230.

    Meng B, Feng X, Qiu G, Liang P, Li P, Chen C, Shang L. The process of methylmercury accumulation in rice (Oryza sativa L.). Environmental Science and Technology. 2011;45:2711-2717.

    Not in our library10.1021/es103384v

  231. 231.

    Meng B, Feng X, Qiu G, Anderson CW, Wang J, Zhao L. Localization and speciation of mercury in brown rice with implications for Pan-Asian public health. Environmental Science and Technology. 2014;48:7974-7981.

    Not in our library10.1021/es502000d

  232. 232.

    Meng M, Li B, Shao J-J, Wang T, He B, Shi J-B, Ye Z-H, Jiang G-B. Accumulation of total mercury and methylmercury in rice plants collected from different mining areas in China. Environmental Pollution. 2014;184:179-186.

    Not in our library10.1016/j.envpol.2013.08.030

  233. 233.

    Merritt KA, Amirbahman A. Methylmercury cycling in estuarine sediment pore waters (Penobscot River estuary, Maine, USA). Limnology and Oceanography. 2008;53:1064-1075.

    Not in our library10.4319/lo.2008.53.3.1064

  234. 234.

    Miller MB, Gustin MS. Testing and modeling the influence of reclamation and control methods for reducing nonpoint mercury emissions associated with industrial open pit gold mines. Journal of the Air and Waste Management Association. 2013;63:681-693.

    Not in our library10.1080/10962247.2013.778221

  235. 235.

    Mitchell CPJ, Gilmour CC. Methylmercury production in a Chesapeake Bay salt marsh. Journal of Geophysical Research—Biogeosciences. 2008;113:G00C04.

    Not in our library

  236. 236.

    Mitchell CP, Branfireun BA, Kolka RK. Total mercury and methylmercury dynamics in upland–peatland watersheds during snowmelt. Biogeochemistry. 2008;90:225-241.

    Not in our library10.1007/s10533-008-9246-z

  237. 237.

    Mitchell CPJ, Branfireun BA, Kolka RK. Assessing sulfate and carbon controls on net methylmercury production in peatlands: An in situ mesocosm approach. Applied Geochemistry. 2008;23:503-518.

    Not in our library10.1016/j.apgeochem.2007.12.020

  238. 238.

    Mitchell CP, Branfireun BA, Kolka RK. Methylmercury dynamics at the upland-peatland interface: Topographic and hydrogeochemical controls. Water Resources Research. 2009;45:W02406.

    Not in our library10.1029/2008wr006832

  239. 239.

    Monperrus M, Tessier E, Point D, Vidimova K, Amouroux D, Guyoneaud R, Leynaert A, Grall J. The biogeochemistry of mercury at the sediment–water interface in the Thau Lagoon. 2. Evaluation of mercury methylation potential in both surface sediment and the water column. Estuarine, Coastal and Shelf Science. 2007;72:485-496.

    Not in our library10.1016/j.ecss.2006.11.014

  240. 240.

    Montgomery S, Lucotte M, Rheault I. Temporal and spatial influences of flooding on dissolved mercury in boreal reservoirs. Science of the Total Environment. 2000;260:147-157.

    Not in our library10.1016/s0048-9697(00)00559-3

  241. 241.

    Mucci A, Montgomery S, Lucotte M, Plourde Y, Pichet P, Tra HV. Mercury remobilization from flooded soils in a hydroelectric reservoir of northern Quebec, La Grande-2: Results of a soil resuspension experiment. Canadian Journal of Fisheries and Aquatic Sciences. 1995;52:2507-2517.

    Not in our library10.1139/f95-841

  242. 242.

    Munthe J, Hultberg H. Mercury and methylmercury in runoff from a forested catchment—Concentrations, fluxes, and their response to manipulations. Water, Air, & Soil Pollution: Focus. 2004;4:607-618.

    Not in our library10.1023/b:wafo.0000028381.04393.ed

  243. 243.

    Munthe J, Bodaly RA, Branfireun BA, Driscoll CT, Gilmour CC, Harris R, Horvat M, Lucotte M, et al. Recovery of mercury-contaminated fisheries. Ambio. 2007;36:33-44.

    Not in our library10.1579/0044-7447(2007)36[33:romf]2.0.co;2

  244. 244.

    Murkin E, Cole DC, Kearney JP, Sheeshka J, Dawson J, Fish and Wildlife Nutrition Project. Fish consumption practices among frequent consuming fishers of five Ontario Great Lakes areas of concern (AOCs). Journal of Great Lakes Research. 2003;29:436-447.

    Not in our library10.1016/s0380-1330(03)70449-3

  245. 245.

    Naik AP, Hammerschmidt CR. Mercury and trace metal partitioning and fluxes in suburban Southwest Ohio watersheds. Water Research. 2011;45:5151-5160.

    Not in our library10.1016/j.watres.2011.07.023

  246. 246.

    New York State Department of Environmental Conservation and U.S. Environmental Protection Agency. Record of Decision: Onondaga Lake Bottom Subsite of the Onondaga Lake Superfund Site. 2005.

    Not in our library

  247. 247.

    Obrist D, Johnson DW, Lindberg SE, Luo Y, Hararuk O, Bracho R, Battles JJ, Dail DB, et al. Mercury distribution across 14 US forests. Part I: Spatial patterns of concentrations in biomass, litter, and soils. Environmental Science and Technology. 2011;45:3974-3981.

    Not in our library10.1021/es104384m

  248. 248.
  249. 249.

    O’Driscoll NJ, Lean DRS, Loseto LL, Carignan R, Siciliano SD. Effect of dissolved organic carbon on the photoproduction of dissolved gaseous mercury in lakes: Potential impacts of forestry. Environmental Science and Technology. 2004;38:2664-2672.

    Not in our library10.1021/es034702a

  250. 250.

    Olsen TA, Brandt CC, Brooks SC. Periphyton biofilms influence net methylmercury production in an industrially contaminated system. Environmental Science and Technology. 2016;50:10843-10850.

    Not in our library10.1021/acs.est.6b01538

  251. 251.

    Ordonez A, Loredo J, De Miguel E, Charlesworth S. Distribution of heavy metals in the street dusts and soils of an industrial city in Northern Spain. Archives of Environmental Contamination and Toxicology. 2003;44:160-170.

    Not in our library10.1007/s00244-002-2005-6

  252. 252.

    Orem W, Gilmour C, Axelrad D, Krabbenhoft D, Scheidt D, Kalla P, McCormick P, Gabriel M, et al. Sulfur in the South Florida Ecosystem: Distribution, sources, biogeochemistry, impacts, and management for restoration. Critical Reviews in Environmental Science and Technology. 2011;41:249-288.

    Not in our library10.1080/10643389.2010.531201

  253. 253.

    Oremland RS, Culbertson CW, Winfrey MR. Methylmercury decomposition in sediments and bacterial cultures—Involvement of methanogens and sulfate reducers in oxidative demethylation. Applied and Environmental Microbiology. 1991;57:130-137.

    Not in our library10.1128/aem.57.1.130-137.1991

  254. 254.

    Orihel DM, Paterson MJ, Blanchfield PJ, Bodaly RA, Gilmour CC, Hintelmann H. Temporal changes in the distribution, methylation, and bioaccumulation of newly deposited mercury in an aquatic ecosystem. Environmental Pollution. 2008;154:77-88.

    Not in our library10.1016/j.envpol.2007.12.030

  255. 255.

    Ortiz VL, Mason RP, Evan Ward J. An examination of the factors influencing mercury and methylmercury particulate distributions, methylation and demethylation rates in laboratory-generated marine snow. Marine Chemistry. 2015;177:753-762.

    Not in our library10.1016/j.marchem.2015.07.006

  256. 256.

    Oswald CJ, Heyes A, Branfireun BA. Fate and transport of ambient mercury and applied mercury isotope in terrestrial upland soils: Insights from the METAALICUS watershed. Environmental Science and Technology. 2014;48:1023-1031.

    Not in our library10.1021/es404260f

  257. 257.

    Parks JM, Johs A, Podar M, Bridou R, Hurt RA, Smith SD, Tomanicek SJ, Qian Y, et al. The genetic basis for bacterial mercury methylation. Science. 2013.

    Not in our library10.1126/science.1230667

  258. 258.

    Paterson MJ, Blanchfield PJ, Podemski C, Hintelmann HH, Gilmour CC, Harris R, Ogrinc N, Rudd JWM, et al. Bioaccumulation of newly deposited mercury by fish and invertebrates: An enclosure study using stable mercury isotopes. Canadian Journal of Fisheries and Aquatic Sciences. 2006;63:2213-2224.

    Not in our library10.1139/f06-118

  259. 259.

    Peng X, Liu F, Wang W-X, Ye Z. Reducing total mercury and methylmercury accumulation in rice grains through water management and deliberate selection of rice cultivars. Environmental Pollution. 2012;162:202-208.

    Not in our library10.1016/j.envpol.2011.11.024

  260. 260.

    Perron T, Chetelat J, Gunn J, Beisner BE, Amyot M. Effects of experimental thermocline and oxycline deepening on methylmercury bioaccumulation in a Canadian Shield Lake. Environmental Science and Technology. 2014;48:2626-2634.

    Not in our library10.1021/es404839t

  261. 261.

    Pham AL-T, Morris A, Zhang T, Ticknor JL, Levard C, Hsu-Kim H. Precipitation of nanoscale mercuric sulfides in the presence of natural organic matter: Structural properties, aggregation, and biotransformation. Geochimica et Cosmochimica Acta. 2014;133:204-215.

    Not in our library10.1016/j.gca.2014.02.027

  262. 262.

    Philippe A, Schaumann GE. Interactions of dissolved organic matter with natural and engineered inorganic colloids: A review. Environmental Science and Technology. 2014;48:8946-8962.

    Not in our library10.1021/es502342r

  263. 263.

    Pickhardt PC, Folt CL, Chen CY, Klaue B, Blum JD. Algal blooms reduce the uptake of toxic methylmercury in freshwater food webs. Proceedings of the National academy of Sciences of the United States of America. 2002;99:4419-4423.

    Not in our library10.1073/pnas.072531099

  264. 264.

    Pickhardt PC, Folt CL, Chen CY, Klaue B, Blum JD. Impacts of zooplankton composition and algal enrichment on the accumulation of mercury in an experimental freshwater food web. Science of the Total Environment. 2005;339:89-101.

    Not in our library10.1016/j.scitotenv.2004.07.025

  265. 265.

    Pirrone N, Cinnirella S, Feng X, Finkelman RB, Friedli HR, Leaner J, Mason R, Mukherjee AB, et al. Global mercury emissions to the atmosphere from anthropogenic and natural sources. Atmospheric Chemistry and Physics. 2010;10:5951-5964.

    Not in our library10.5194/acp-10-5951-2010

  266. 266.

    Podar M, Gilmour CC, Brandt CC, Soren A, Brown SD, Crable BR, Palumbo AV, Somenahally AC, et al. Global prevalence and distribution of genes and microorganisms involved in mercury methylation. Science Advances. 2015;1:e1500675.

    Not in our library10.1126/sciadv.1500675

  267. 267.

    Porvari P, Verta M. Methylmercury production in flooded soils—A laboratory study. Water, Air, and Soil pollution. 1995;80:765-773.

    Not in our library10.1007/bf01189728

  268. 268.

    Porvari P, Verta M, Munthe J, Haapanen M. Forestry practices increase mercury and methyl mercury output from boreal forest catchments. Environmental Science and Technology. 2003;37:2389-2393.

    Not in our library10.1021/es0340174

  269. 269.

    Poulin BA, Ryan JN, Nagy KL, Stubbins A, Dittmar T, Orem W, Krabbenhoft DP, Aiken GR. Spatial dependence of reduced sulfur in everglades dissolved organic matter controlled by sulfate enrichment. Environmental Science and Technology. 2017;51:3630-3639.

    Not in our library10.1021/acs.est.6b04142

  270. 270.

    Qiu G, Feng X, Li P, Wang S, Li G, Shang L, Fu X. Methylmercury accumulation in rice (Oryza sativa L.) grown at abandoned mercury mines in Guizhou, China. Journal of Agricultural and Food Chemistry. 2008;56:2465-2468.

    Not in our library10.1021/jf073391a

  271. 271.

    Ranchou-Peyruse M, Monperrus M, Bridou R, Duran R, Amouroux D, Salvado JC, Guyoneaud R. Overview of mercury methylation capacities among anaerobic bacteria including representatives of the sulphate-reducers: Implications for environmental studies. Geomicrobiology Journal. 2009;26:1-8.

    Not in our library10.1080/01490450802599227

  272. 272.

    Randall PM, Chattopadhyay S. Mercury contaminated sediment sites—An evaluation of remedial options. Environmental Research. 2013;125:131-149.

    Not in our library10.1016/j.envres.2013.01.007

  273. 273.

    Rask M, Verta M, Korhonen M, Salo S, Forsius M, Arvola L, Jones RI, Kiljunen M. Does lake thermocline depth affect methyl mercury concentrations in fish? Biogeochemistry. 2010;101:311-322.

    Not in our library10.1007/s10533-010-9487-5

  274. 274.

    Rea A, Lindberg S, Scherbatskoy T, Keeler GJ. Mercury accumulation in foliage over time in two northern mixed-hardwood forests. Water, Air, and Soil pollution. 2002;133:49-67.

    Not in our library10.1023/a:1012919731598

  275. 275.

    Reichelt-Brushett AJ, Stone J, Howe P, Thomas B, Clark M, Male Y, Nanlohy A, Butcher P. Geochemistry and mercury contamination in receiving environments of artisanal mining wastes and identified concerns for food safety. Environmental Research. 2017;152:407-418.

    Not in our library10.1016/j.envres.2016.07.007

  276. 276.

    Rice KC. Trace-element concentrations in streambed sediment across the conterminous United States. Environmental Science and Technology. 1999;33:2499-2504.

    Not in our library10.1021/es990052s

  277. 277.

    Robins N, Hagan N, Halabi S, Hsu-Kim H, Espinoza Gonzales RD, Morris M, Woodall G, Richter D, et al. Estimations of historical atmospheric mercury concentrations from mercury refining and present-day soil concentrations of total mercury in Huancavelica, Peru. Science of the Total Environment. 2012;426:145-154.

    Not in our library10.1016/j.scitotenv.2012.03.082

  278. 278.

    Rodrigues SM, Coelho C, Cruz N, Monteiro RJR, Henriques B, Duarte AC, Romkens P, Pereira E. Oral bioaccessibility and human exposure to anthropogenic and geogenic mercury in urban, industrial and mining areas. Science of the Total Environment. 2014;496:649-661.

    Not in our library10.1016/j.scitotenv.2014.06.115

  279. 279.

    Rothenberg SE, Feng X. Mercury cycling in a flooded rice paddy. Journal of Geophysical Research: Biogeosciences. 2012;117:G03003.

    Not in our library10.1029/2011jg001800

  280. 280.

    Rothenberg SE, Feng X, Dong B, Shang L, Yin R, Yuan X. Characterization of mercury species in brown and white rice (Oryza sativa L.) grown in water-saving paddies. Environmental Pollution. 2011;159:1283-1289.

    Not in our library10.1016/j.envpol.2011.01.027

  281. 281.

    Rothenberg SE, Windham-Myers L, Creswell JE. Rice methylmercury exposure and mitigation: A comprehensive review. Environmental Research. 2014;133:407-423.

    Not in our library10.1016/j.envres.2014.03.001

  282. 282.

    Rothenberg SE, Anders M, Ajami NJ, Petrosino JF, Balogh E. Water management impacts rice methylmercury and the soil microbiome. Science of the Total Environment. 2016;572:608-617.

    Not in our library10.1016/j.scitotenv.2016.07.017

  283. 283.

    Roulet M, Lucotte M, Farella N, Serique G, Coelho H, Passos CJS, da Silva ED, de Andrade PS, et al. Effects of recent human colonization on the presence of mercury in Amazonian ecosystems. Water, Air, and Soil pollution. 1999;112:297-313.

    Not in our library10.1023/a:1005073432015

  284. 284.

    Roulet M, Lucotte M, Canuel R, Farella N, Courcelles M, Guimaraes JRD, Mergler D, Amorim M. Increase in mercury contamination recorded in lacustrine sediments following deforestation in the central Amazon. Chemical Geology. 2000;165:243-266.

    Not in our library10.1016/s0009-2541(99)00172-2

  285. 285.

    Rowland AP, Neal C, Scholefield P, Halford AP, Vincent CD, Hockenhull K. Mercury in rivers in NW England: From rural headwaters to the heartlands of the historic industrial base. Journal of Environmental Monitoring. 2010;12:2299-2306.

    Not in our library10.1039/c0em00398k

  286. 286.

    Rudd, J., R. Harris, and P. Sellers. 2016. Advice on mercury remediation options for the Wabigoon-English River System. Final Report.

    Not in our library

  287. 287.

    Rudd JWM, Turner MA, Furutani A, Swick AL, Townsend BE. The English Wabigoon river system. 1. A synthesis of recent research with a view towards mercury amelioration. Canadian Journal of Fisheries and Aquatic Sciences. 1983;40:2206-2217.

    Not in our library10.1139/f83-257

  288. 288.

    Rumbold DG, Fink LE. Extreme spatial variability and unprecedented methylmercury concentrations within a constructed wetland. Environmental Monitoring and Assessment. 2006;112:115-135.

    Not in our library10.1007/s10661-006-0767-4

  289. 289.

    Rytuba JJ. Mercury mine drainage and processes that control its environmental impact. Science of the Total Environment. 2000;260:57-71.

    Not in our library10.1016/s0048-9697(00)00541-6

  290. 290.

    Sampaio Da Silva D, Lucotte M, Roulet M, Poirier H, Mergler D, Santos EO, Crossa M. Trophic structure and bioaccumulation of mercury in fish of three natural lakes of the Brazilian Amazon. Water, Air, and Soil pollution. 2005;165:77-94.

    Not in our library10.1007/s11270-005-4811-8

  291. 291.

    Schaefer JK, Rocks SS, Zheng W, Liang L, Gu B, Morel FMM. Active transport, substrate specificity, and methylation of Hg(II) in anaerobic bacteria. Proceedings of the National academy of Sciences of the United States of America. 2011;108:8714-8719.

    Not in our library10.1073/pnas.1105781108

  292. 292.

    Schaefer JK, Szczuka A, Morel FMM. Effect of divalent metals on Hg(II) uptake and methylation by bacteria. Environmental Science and Technology. 2014;48:3007-3013.

    Not in our library10.1021/es405215v

  293. 293.

    Schetagne, R. and J. Therrien. 2013. Suivi environnemental du complexe La Grande. Évolution des teneurs en mercure dans les poissons. Rapport synthèse 1978-2012. Hydro Quebec.

    Not in our library

  294. 294.

    Scheuhammer AM, Meyer MW, Sandheinrich MB, Murray MW. Effects of environmental methylmercury on the health of wild birds, mammals, and fish. Ambio. 2007;36:12-18.

    Not in our library10.1579/0044-7447(2007)36[12:eoemot]2.0.co;2

  295. 295.

    Schroeder WH, Munthe J. Atmospheric mercury—An overview. Atmospheric Environment. 1998;32:809-822.

    Not in our library10.1016/s1352-2310(97)00293-8

  296. 296.

    Schuster PF, Shanley JB, Marvin-Dipasquale M, Reddy MM, Aiken GR, Roth DA, Taylor HE, Krabbenhoft DP, et al. Mercury and organic carbon dynamics during runoff episodes from a northeastern USA watershed. Water, Air, and Soil pollution. 2008;187:89-108.

    Not in our library10.1007/s11270-007-9500-3

  297. 297.

    Schuster PF, Striegl RG, Aiken GR, Krabbenhoft DP, Dewild JF, Butler K, Kamark B, Dornblaser M. Mercury export from the Yukon River Basin and potential response to a changing climate. Environmental Science and Technology. 2011;45:9262-9267.

    Not in our library10.1021/es202068b

  298. 298.

    Scudder, B. C., Chasar, L.C., Wentz, D.A., Bauch, N.J., Brigham, M.E., Moran, P.W., and Krabbenhoft, D.P. 2009. Mercury in fish, bed sediment, and water from streams across the United States, 1998–2005. Scientific Investigations Report 2009-5109. U.S. Geological Survey.

    Not in our library

  299. 299.

    Selin NE. Global biogeochemical cycling of mercury: A review. Annual Review of Environment and Resources. 2009;34:43-63.

    Not in our library10.1146/annurev.environ.051308.084314

  300. 300.

    Selin, H., S.E. Keane, S. Wang, N.E. Selin, K. Davis, and D. Bally. 2018. Linking science and policy to support the implementation of the Minamata Convention on Mercury. Ambio. 10.1007/s13280-017-1003-x.

    Not in our library10.1007/s13280-017-1003-x

  301. 301.

    Sellers P, Kelly C, Rudd J, MacHutchon A. Photodegradation of methylmercury in lakes. Nature. 1996;380:694.

    Not in our library10.1038/380694a0

  302. 302.

    Shanley JB, Mast MA, Campbell DH, Aiken GR, Krabbenhoft DP, Hunt RJ, Walker JF, Schuster PF, et al. Comparison of total mercury and methylmercury cycling at five sites using the small watershed approach. Environmental Pollution. 2008;154:143-154.

    Not in our library10.1016/j.envpol.2007.12.031

  303. 303.

    Sherman LS, Blum JD, Dvonch JT, Gratz LE, Landis MS. The use of Pb, Sr, and Hg isotopes in Great Lakes precipitation as a tool for pollution source attribution. Science of the Total Environment. 2015;502:362-374.

    Not in our library10.1016/j.scitotenv.2014.09.034

  304. 304.

    Shiklomanov IA, Rodda JC. World water resources at the beginning of the twenty-first century. 2004.

    Not in our library

  305. 305.

    Simmons DBD, Wallschläger D. A critical review of the biogeochemistry and ecotoxicology of selenium in lotic and lentic environments. Environmental Toxicology and Chemistry. 2005;24:1331-1343.

    Not in our library10.1897/04-176r.1

  306. 306.

    Simmons-Willis TA, Clarkson TW, Ballatori N. Transport of a neurotoxicant by molecular mimicry: The methylmercury-l-cysteine complex is a substrate for human L-type large neutral amino acid transporter (LAT) 1 and LAT2. Biochemical Journal. 2002;367:239-246.

    Not in our library10.1042/bj20020841

  307. 307.

    Sinclair KA, Xie Q, Mitchell CPJ. Methylmercury in water, sediment, and invertebrates in created wetlands of Rouge Park, Toronto, Canada. Environmental Pollution. 2012;171:207-215.

    Not in our library10.1016/j.envpol.2012.07.043

  308. 308.

    Skyllberg U, Liu G, Cai Y, O’Driscoll N. Chemical speciation of mercury in soil and sediment. Environmental chemistry and toxicology of mercury. 2012;219-258.

    Not in our library

  309. 309.

    Skyllberg U, Drott A, Lambertsson L, Björn E, Karlsson T, Johnson T, Heinemo S-Å, Holmström H. Net methylmercury production as a basis for improved risk assessment of mercury-contaminated sediments. Ambio. 2007;36:437-442.

    Not in our library10.1579/0044-7447(2007)36[437:nmpaab]2.0.co;2

  310. 310.

    Skyllberg U, Westin MB, Meili M, Bjorn E. Elevated concentrations of methyl mercury in streams after forest clear-cut: A consequence of mobilization from soil or new methylation? Environmental Science and Technology. 2009;43:8535-8541.

    Not in our library10.1021/es900996z

  311. 311.

    Slotton DG, Reuter JE, Goldman CR. Mercury uptake patterns of biota in a seasonally anoxic northern California Reservoir. Water, Air, and Soil pollution. 1995;80:841-850.

    Not in our library10.1007/bf01189735

  312. 312.

    Soerensen AL, Schartup AT, Gustafsson E, Gustafsson BG, Undeman E, Björn E. Eutrophication increases phytoplankton methylmercury concentrations in a coastal sea—A Baltic Sea case study. Environmental Science and Technology. 2016;50:11787-11796.

    Not in our library10.1021/acs.est.6b02717

  313. 313.

    Sorensen R, Meili M, Lambertsson L, von Bromssen C, Bishop K. The effects of forest harvest operations on mercury and methylmercury in two boreal streams: Relatively small changes in the first two years prior to site preparation. Ambio. 2009;38:364-372.

    Not in our library10.1579/0044-7447-38.7.364

  314. 314.

    Southworth, G. R., M. Greeley, M. Peterson, K. Lowe, and R. Ketelle. 2010. Sources of Mercury to East Fork Poplar Creek Downstream from the Y-12 National Security Complex: Inventories and Export Rates. Oak Ridge National Laboratory, Oak Ridge.

    Not in our library

  315. 315.

    Spiegel SJ, Veiga MM. International guidelines on mercury management in small-scale gold mining. Journal of Cleaner Production. 2010;18:375-385.

    Not in our library10.1016/j.jclepro.2009.10.020

  316. 316.

    St. Louis VL, Rudd JW, Kelly CA, Beaty KG, Bloom NS, Flett RJ. Importance of wetlands as sources of methyl mercury to boreal forest ecosystems. Canadian Journal of Fisheries and Aquatic Sciences. 1994;51:1065-1076.

    Not in our library10.1139/f94-106

  317. 317.

    St. Louis VL, Rudd JW, Kelly CA, Bodaly R, Paterson MJ, Beaty KG, Hesslein RH, Heyes A, et al. The rise and fall of mercury methylation in an experimental reservoir. Environmental Science and Technology. 2004;38:1348-1358.

    Not in our library10.1021/es034424f

  318. 318.

    Stamenkovic J, Gustin MS, Dennett KE. Net methyl mercury production versus water quality improvement in constructed wetlands: Trade-offs in pollution control. Wetlands. 2005;25:748-757.

    Not in our library10.1672/0277-5212(2005)025[0748:nmmpvw]2.0.co;2

  319. 319.

    Stoken OM, Riscassi AL, Scanlon TM. Association of dissolved mercury with dissolved organic carbon in US rivers and streams: The role of watershed soil organic carbon. Water Resources Research. 2016;52:3040-3051.

    Not in our library10.1002/2015wr017849

  320. 320.

    Strickman R, Mitchell C. Accumulation and translocation of methylmercury and inorganic mercury in Oryza sativa: An enriched isotope tracer study. Science of the Total Environment. 2017;574:1415-1423.

    Not in our library10.1016/j.scitotenv.2016.08.068

  321. 321.

    Strickman RJ, Mitchell CPJ. Methylmercury production and accumulation in urban stormwater ponds and habitat wetlands. Environmental Pollution. 2017;221:326-334.

    Not in our library10.1016/j.envpol.2016.11.082

  322. 322.
  323. 323.

    Tang W, Cheng J, Zhao W, Wang W. Mercury levels and estimated total daily intakes for children and adults from an electronic waste recycling area in Taizhou, China: Key role of rice and fish consumption. Journal of Environmental Sciences. 2015;34:107-115.

    Not in our library10.1016/j.jes.2015.01.029

  324. 324.

    Tanner KC, Windham-Myers L, Fleck JA, Tate KW, McCord SA, Linquist BA. The contribution of Rice agriculture to methylmercury in surface waters: A review of data from the Sacramento Valley, California. Journal of Environmental Quality. 2017;46:133-142.

    Not in our library10.2134/jeq2016.07.0262

  325. 325.

    Tarras-Wahlberg NH, Flachier A, Lane SN, Sangfors O. Environmental impacts and metal exposure of aquatic ecosystems in rivers contaminated by small scale gold mining: The Puyango River basin, southern Ecuador. Science of the Total Environment. 2001;278:239-261.

    Not in our library10.1016/s0048-9697(01)00655-6

  326. 326.

    Telmer KH, Veiga MM, Mason R, Pirrone N. World emissions of mercury from artisanal and small scale gold mining. Mercury Fate and Transport in the Global Atmosphere: Emissions, Measurements and Models. 2009;131-172.

    Not in our library

  327. 327.

    Ticknor J, Kucharzyk KH, Porter KA, Deshusses MA, Hsu-Kim H. Thiol-based selective extraction assay to comparatively assess bioavailable mercury in sediments. Environmental Engineering Science. 2015;32:564-573.

    Not in our library10.1089/ees.2014.0526

  328. 328.

    Tjerngren I, Karlsson T, Bjorn E, Skyllberg U. Potential Hg methylation and MeHg demethylation rates related to the nutrient status of different boreal wetlands. Biogeochemistry. 2012;108:335-350.

    Not in our library10.1007/s10533-011-9603-1

  329. 329.

    Tomiyasu T, Matsuyama A, Eguchi T, Fuchigami Y, Oki K, Horvat M, Rajar R, Akagi H. Spatial variations of mercury in sediment of Minamata Bay, Japan. Science of the Total Environment. 2006;368:283-290.

    Not in our library10.1016/j.scitotenv.2005.09.090

  330. 330.

    Tong YD, Zhang W, Hu D, Ou LB, Hu XD, Yang TJ, Wei W, Ju L, et al. Behavior of mercury in an urban river and its accumulation in aquatic plants. Environmental Earth Sciences. 2013;68:1089-1097.

    Not in our library10.1007/s12665-012-1810-0

  331. 331.

    Tuomola L, Niklasson T, de Castro E Silva E, Hylander LD. Fish mercury development in relation to abiotic characteristics and carbon sources in a six-year-old, Brazilian reservoir. Science of the Total Environment. 2008;390:177-187.

    Not in our library10.1016/j.scitotenv.2007.09.030

  332. 332.

    Ukonmaanaho L, Starr M, Kantola M, Lauren A, Piispanen J, Pietila H, Peramaki P, Merila P, et al. Impacts of forest harvesting on mobilization of Hg and MeHg in drained peatland forests on black schist or felsic bedrock. Environmental Monitoring and Assessment. 2016;188:228.

    Not in our library10.1007/s10661-016-5210-x

  333. 333.

    Ullrich SM, Tanton TW, Abdrashitova SA. Mercury in the aquatic environment: A review of factors affecting methylation. Critical Reviews in Environmental Science and Technology. 2001;31:241-293.

    Not in our library10.1080/20016491089226

  334. 334.

    Ullrich SM, Ilyushchenko MA, Kamberov IM, Tanton TW. Mercury contamination in the vicinity of a derelict chlor-alkali plant. Part I: Sediment and water contamination of Lake Balkyldak and the River Irtysh. Science of the Total Environment. 2007;381:1-16.

    Not in our library10.1016/j.scitotenv.2007.02.033

  335. 335.

    Ullrich SM, Ilyushchenko MA, Tanton TW, Uskov GA. Mercury contamination in the vicinity of a derelict chlor-alkali plant: Part II: Contamination of the aquatic and terrestrial food chain and potential risks to the local population. Science of the Total Environment. 2007;381:290-306.

    Not in our library10.1016/j.scitotenv.2007.02.020

  336. 336.

    Ulrich PD, Sedlak DL. Impact of iron amendment on net methylmercury export from tidal wetland microcosms. Environmental Science and Technology. 2010;44:7659-7665.

    Not in our library10.1021/es1018256

  337. 337.

    United Nations Environment Programme. Global Mercury Assessment 2013: Sources, emissions, releases, and environmental transport. 2013.

    Not in our library

  338. 338.

    Van Furl C, Colman JA, Bothner MH. Mercury sources to Lake Ozette and Lake Dickey: Highly contaminated remote coastal lakes, Washington State, USA. Water, Air, and Soil pollution. 2010;208:275-286.

    Not in our library10.1007/s11270-009-0165-y

  339. 339.

    van Straaten P. Mercury contamination associated with small-scale gold mining in Tanzania and Zimbabwe. Science of the Total Environment. 2000;259:105-113.

    Not in our library10.1016/s0048-9697(00)00553-2

  340. 340.

    Vaze J, Chiew FHS. Study of pollutant washoff from small impervious experimental plots. Water Resources Research. 2003;39:1160.

    Not in our library

  341. 341.

    Veiga MM, Maxson PA, Hylander LD. Origin and consumption of mercury in small-scale gold mining. Journal of Cleaner Production. 2006;14:436-447.

    Not in our library10.1016/j.jclepro.2004.08.010

  342. 342.

    Veiga MM, Angeloci-Santos G, Meech JA. Review of barriers to reduce mercury use in artisanal gold mining. The Extractive Industries and Society. 2014;1:351-361.

    Not in our library10.1016/j.exis.2014.03.004

  343. 343.

    Velásquez-López PC, Veiga MM, Klein B, Shandro JA, Hall K. Cyanidation of mercury-rich tailings in artisanal and small-scale gold mining: Identifying strategies to manage environmental risks in Southern Ecuador. Journal of Cleaner Production. 2011;19:1125-1133.

    Not in our library10.1016/j.jclepro.2010.09.008

  344. 344.

    Verta, M., S. Rekolainen, and K. Kinnunen. 1986. Causes of increased fish mercury levels in Finnish reservoirs.

    Not in our library

  345. 345.

    Vost EE, Amyot M, O’Driscoll NJ, Liu G, Cai Y, O’Driscoll N. Photoreactions of mercury in aquatic systems. Environmental chemistry and toxicology of mercury. 2012;193-218.

    Not in our library

  346. 346.

    Wallschlager D, Hintelmann H, Evans RD, Wilken RD. Volatilization of dimethylmercury and elemental mercury from River Elbe floodplain soils. Water, Air, and Soil pollution. 1995;80:1325-1329.

    Not in our library10.1007/bf01189798

  347. 347.

    Wang Q, Kim D, Dionysiou DD, Sorial GA, Timberlake D. Sources and remediation for mercury contamination in aquatic systems—A literature review. Environmental Pollution. 2004;131:323-336.

    Not in our library10.1016/j.envpol.2004.01.010

  348. 348.

    Wang J, Feng X, Anderson CWN, Xing Y, Shang L. Remediation of mercury contaminated sites—A review. Journal of Hazardous Materials. 2012;221–222:1-18.

    Not in our library10.1016/j.jhazmat.2012.04.035

  349. 349.

    Wang X, Li B, Tam NF-Y, Huang L, Qi X, Wang H, Ye Z, Meng M, et al. Radial oxygen loss has different effects on the accumulation of total mercury and methylmercury in rice. Plant and Soil. 2014;385:343-355.

    Not in our library10.1007/s11104-014-2239-x

  350. 350.

    Wang Y-J, Dang F, Zhao J-T, Zhong H. Selenium inhibits sulfate-mediated methylmercury production in rice paddy soil. Environmental Pollution. 2016;213:232-239.

    Not in our library10.1016/j.envpol.2016.02.021

  351. 351.

    Watras C, Morrison K. The response of two remote, temperate lakes to changes in atmospheric mercury deposition, sulfate, and the water cycle. Canadian Journal of Fisheries and Aquatic Sciences. 2008;65:100-116.

    Not in our library10.1139/f07-159

  352. 352.

    Watras CJ, Morrison KA, Host JS, Bloom NS. Concentration of mercury species in relationship to other site-specific factors in the surface waters of northern Wisconsin lakes. Limnology and Oceanography. 1995;40:556-565.

    Not in our library10.4319/lo.1995.40.3.0556

  353. 353.

    Wiederhold JG, Skyllberg U, Drott A, Jiskra M, Jonsson S, Björn E, Bourdon B, Kretzschmar R. Mercury isotope signatures in contaminated sediments as a tracer for local industrial pollution sources. Environmental Science and Technology. 2015;49:177-185.

    Not in our library10.1021/es5044358

  354. 354.

    Willacker JJ, Eagles-Smith CA, Lutz MA, Tate MT, Lepak JM, Ackerman JT. Reservoirs and water management influence fish mercury concentrations in the western United States and Canada. Science of the Total Environment. 2016;568:739-748.

    Not in our library10.1016/j.scitotenv.2016.03.050

  355. 355.

    Windham-Myers L, Marvin-DiPasquale M, Kakouros E, Agee JL, Kieu LH, Stricker CA, Fleck JA, Ackerman JT. Mercury cycling in agricultural and managed wetlands of California, USA: Seasonal influences of vegetation on mercury methylation, storage, and transport. Science of the Total Environment. 2014;484:308-318.

    Not in our library10.1016/j.scitotenv.2013.05.027

  356. 356.

    Windham-Myers L, Marvin-DiPasquale M, Stricker CA, Agee JL, Kieu LH, Kakouros E. Mercury cycling in agricultural and managed wetlands of California, USA: Experimental evidence of vegetation-driven changes in sediment biogeochemistry and methylmercury production. Science of the Total Environment. 2014;484:300-307.

    Not in our library10.1016/j.scitotenv.2013.05.028

  357. 357.

    Wip D, Warneke T, Petersen AK, Notholt J, Temme C, Kock H, Cordy P. Urban mercury pollution in the City of Paramaribo, Suriname. Air Quality, Atmosphere and Health. 2013;6:205-213.

    Not in our library10.1007/s11869-011-0162-3

  358. 358.

    Wolff BA, Johnson BM, Lepak JM. Changes in sport fish mercury concentrations from food web shifts suggest partial decoupling from atmospheric deposition in two colorado reservoirs. Archives of Environmental Contamination and Toxicology. 2017;72:167-177.

    Not in our library10.1007/s00244-016-0353-x

  359. 359.

    Yu R-Q, Reinfelder JR, Hines ME, Barkay T. Mercury methylation by the methanogen Methanospirillum hungatei. Applied and Environmental Microbiology. 2013;79:6325-6330.

    Not in our library10.1128/aem.01556-13

  360. 360.

    Zhang T, Hsu-Kim H. Photolytic degradation of methylmercury enhanced by binding to natural organic ligands. Nature Geoscience. 2010;3:473-476.

    Not in our library10.1038/ngeo892

  361. 361.
  362. 362.

    Zhang H, Feng X, Zhu J, Sapkota A, Meng B, Yao H, Qin H, Larssen T. Selenium in soil inhibits mercury uptake and translocation in rice (Oryza sativa L.). Environmental Science and Technology. 2012;46:10040-10046.

    Not in our library10.1021/es302245r

  363. 363.

    Zhang T, Kim B, Levard C, Reinsch BC, Lowry GV, Deshusses MA, Hsu-Kim H. Methylation of mercury by bacteria exposed to dissolved, nanoparticulate, and microparticulate mercuric sulfides. Environmental Science and Technology. 2012;46:6950-6958.

    Not in our library10.1021/es203181m

  364. 364.

    Zhang H, Feng X, Jiang C, Li Q, Liu Y, Gu C, Shang L, Li P, et al. Understanding the paradox of selenium contamination in mercury mining areas: High soil content and low accumulation in rice. Environmental Pollution. 2014;188:27-36.

    Not in our library10.1016/j.envpol.2014.01.012

  365. 365.

    Zhang T, Kucharzyk KH, Kim B, Deshusses MA, Hsu-Kim H. Net methylation of mercury in estuarine sediment microcosms amended with dissolved, nanoparticulate, and microparticulate mercuric sulfides. Environmental Science and Technology. 2014;48:9133-9141.

    Not in our library10.1021/es500336j

  366. 366.

    Zhao J, Li Y, Li Y, Gao Y, Li B, Hu Y, Zhao Y, Chai Z. Selenium modulates mercury uptake and distribution in rice (Oryza sativa L.), in correlation with mercury species and exposure level. Metallomics. 2014;6:1951-1957.

    Not in our library10.1039/c4mt00170b

  367. 367.

    Zouabi-Aloui B, Adelana SM, Gueddari M. Effects of selective withdrawal on hydrodynamics and water quality of a thermally stratified reservoir in the southern side of the Mediterranean Sea: A simulation approach. Environmental Monitoring and Assessment. 2015;187:292.

    Not in our library10.1007/s10661-015-4509-3

Cited by papers we hold 2

Reads

Read by people on this page

None yet.

Checked or read by AI through naulon

None yet.

A person counts once a day per paper. We keep no cookie and no address: a reader is a hash that changes every day. Any month under five reads shows no number.

Are you an author?

Is this your paper?

Claim it to add your note and be paid when agents cite it. Free.