A synthesis of patterns of environmental mercury inputs, exposure and effects in New York State

Abstract

Mercury (Hg) pollution is an environmental problem that adversely affects human and ecosystem health at local, regional, and global scales—including within New York State. More than two-thirds of the Hg currently released to the environment originates, either directly or indirectly, from human activities. Since the early 1800s, global atmospheric Hg concentrations have increased by three- to eight-fold over natural levels. In the U.S., atmospheric emissions and point-source releases to waterways increased following industrialization into the mid-1980s. Since then, water discharges have largely been curtailed. As a result, Hg emissions, atmospheric concentrations, and deposition over the past few decades have declined across the eastern U.S. Despite these decreases, Hg pollution persists. To inform policy efforts and to advance public understanding, the New York State Energy Research and Development Authority (NYSERDA) sponsored a scientific synthesis of information on Hg in New York State. This effort includes 23 papers focused on Hg in atmospheric deposition, water, fish, and wildlife published in Ecotoxicology. New York State experiences Hg contamination largely due to atmospheric deposition. Some landscapes are inherently sensitive to Hg inputs driven by the transport of inorganic Hg to zones of methylation, the conversion of inorganic Hg to methylmercury, and the bioaccumulation and biomagnification along food webs. Mercury concentrations exceed human and ecological risk thresholds in many areas of New York State, particularly the Adirondacks, Catskills, and parts of Long Island. Mercury concentrations in some biota have declined in the Eastern Great Lakes Lowlands and the Northeastern Highlands over the last four decades, concurrent with decreases in water releases and air emissions from regional and U.S. sources. However, widespread changes have not occurred in other ecoregions of New York State. While the timing and magnitude of the response of Hg levels in biota varies, policies expected to further diminish Hg emissions should continue to decrease Hg concentrations in food webs, yielding benefits to the fish, wildlife, and people of New York State. Anticipated improvements in the Hg status of aquatic ecosystems are likely to be greatest for inland surface waters and should be roughly proportional to declines in atmospheric Hg deposition. Efforts that advance recovery from Hg pollution in recent years have yielded significant progress, but Hg remains a pollutant of concern. Indeed, due to this extensive compilation of Hg observations in biota, it appears that the extent and intensity of the contamination on the New York landscape and waterscape is greater than previously recognized. Understanding the extent of Hg contamination and recovery following decreases in atmospheric Hg deposition will require further study, underscoring the need to continue existing monitoring efforts.

Utility of Diffusive Gradient in Thin-Film Passive Samplers for Predicting Mercury Methylation Potential and Bioaccumulation in Freshwater Wetlands

“…The distribution and speciation of MeHg are also key factors for the bioaccumulation of MeHg in the aquatic food web. MeHg concentrations in aquatic organisms can be highly variable between different locations. − While such differences are partly attributed to the localized ecosystem food web structure and dietary preferences, the bioavailability of MeHg at key entry points of the food web is also an important driver. , MeHg species are composed of sorbed and aqueous complexes of CH 3 Hg + , which generally entail coordination to thiolate moieties associated with NOM. , …”

Global mercury concentrations in biota: their use as a basis for a global biomonitoring framework

“…In the northeastern United States, records are decades long for fish. The patterns here are complex, despite documented decreases in atmospheric deposition and regional Hg emissions to the atmosphere (Evers et al 2020 ). While fish of some species have shown long-term declines, gamefish (e.g., largemouth bass) have had stable Hg concentrations (Richter and Skinner 2020 ).…”

“…A recent example of robust Hg monitoring efforts happening at a local level that are linked to local and regional policy regulations to lower Hg emissions and releases from anthropogenic sources is within New York State in the United States. Here, over 47,000 Hg concentrations have been collected in biota over nearly a 50-year period alongside detailed measurements in atmospheric deposition (both wet and dry) across the state (Evers et al 2020 ). However, it was not until this information was collected into a standardized database designed to answer specific, policy-related questions that it was possible to adequately assess the status and trends of Hg contamination and risk, and to design more cost-effective monitoring programs in the future.…”

“…Lastly, published studies included here are those for which there is reasonable confidence about their validity, including those with: (1) sufficient description of the characteristics of the organism sampled (i.e., species, date, location, size/age, and tissue analyzed); (2) an appropriate method of sample collection; and (3) detailed information on sampling location (i.e., market-based fish Hg concentrations are excluded). For North America, extensive biotic Hg datasets published in response to three regional, one state, and one National Park synthesis efforts are included for the: (1) northeastern United States and eastern Canada (Evers and Clair 2005 ), (2) Great Lakes Region of the United States and Canada (Evers et al 2011a ), (3) western United States and Canada (Eagles-Smith et al 2016b ), (4) New York State (Evers et al 2020 ), and (5) Acadia National Park, Maine, United States (Burton et al 2024 ); although, all of the data are not mapped (Fig. 1 and see qualifiers “a” and “b”).…”

“…Contamination can arise directly from inorganic Hg point sources, such as those along rivers (Jackson et al 2011a ; Kinghorn et al 2007 ; Nguetseng et al 2015 ; Santschi et al 2017 ; Geyer and Ralston 2018 ), around lakes (Anderson et al 2008 ; Suchanek et al 2008 ; Kumari and Maiti 2019 ; Chen et al 2021 ), and in estuaries (Eagles-Smith and Ackerman 2009 ; Chen et al 2014 ; Buckman et al 2015 ; Sullivan and Kopec 2018 ). Owing to atmospheric transport, inorganic Hg sources may not be local (i.e., <100 km) and subsequent impacts to biota are well described in most continents, including North America (Evers and Clair 2005 ; Evers et al 2011a ; Ackerman et al 2016 ; Eagles-Smith et al 2016a , b ; Evers et al 2020 ; AMAP 2021 ), South America (Sebastiano et al 2016 ; May Junior et al 2017 ; Manhães et al 2022 ), Europe (Åkerblom et al 2014 ; Nguetseng et al 2015 ; Pacyna et al 2017 ), Asia (Kim et al 2012 ; Watanuki et al 2016 ; Abeysinghe et al 2017 ; Noh et al 2017 ), Africa (Hanna et al 2015 ; van Rooyen et al 2023 ), and multiple ocean basins (Carravieri et al 2014 , 2016 ; Peterson et al 2015 ; Drevnick et al 2015 ; Lee et al 2016 ; Bodin et al 2017 ; Drevnick and Brooks 2017 ; Chastel et al 2022 ).…”