The distribution of mercury (Hg) and methylmercury (MeHg) in paddy soil and rice grain (polished), and Hg in surface waters and gaseous elemental Hg (GEM) in atmosphere at the Yanwuping Hg mining district (YMM), Guizhou Province, China was investigated. Results exhibited high total Hg (Hg(T)) and MeHg concentrations in soil at sites adjacent to calcine pile and tailings, and ranged from 5.6 to 240mgkg(-1) and 0.66 to 7.3μgkg(-1), respectively. Concentrations of Hg(T) in rice ranged from 10 to 45μgkg(-1), and high MeHg concentrations were also observed ranging from 3.2 to 39μgkg(-1). The elevated Hg(T) and MeHg concentrations in soil in the vicinity of calcine pile and tailings reflected in high MeHg concentrations in rice. Those data were significantly correlated with MeHg concentration in soil confirming that soil is the major source of MeHg in rice. The highest Hg concentrations in water, otherwise rather low, ranging from 3.8 to 51ngl(-1) for Hg(T) and of 0.14 to 2.7ngl(-1) for MeHg(T), were found at the proximity of calcine pile suggesting that untreated mine wastes are the principal source of Hg in the nearby area. Huge emissions of GEM were also detected from calcines affecting the whole area, ranging from 12 to 180ngm(-3) with an average of 46±35ngm(-3). The distribution patterns of Hg and MeHg observed in the environmental compartments suggest an elevated contamination of Hg in the region. Elevated high MeHg concentrations in rice might pose a potential health risk to local populations.
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http://dx.doi.org/10.1016/j.envres.2013.01.008 | DOI Listing |
Environ Toxicol Chem
January 2025
New Jersey Water Science Center, U.S. Geological Survey, Lawrenceville, NJ, United States.
Rapid warming in polar regions is causing large changes to ecosystems, including altering environmentally available mercury (Hg). Although subarctic freshwater systems have simple vertebrate communities, Hg in amphibians remains unexplored. We measured total Hg (THg) in wetland sediments and methylmercury (MeHg) in multiple life-stages (eggs to adults) of wood frogs (Rana sylvatica) and larval boreal chorus frogs (Pseudacris maculata) from up to 25 wetlands near Churchill, Manitoba (Canada), during the summers of 2018-2019.
View Article and Find Full Text PDFChemosphere
January 2025
Department of Biology, Wilfrid Laurier University, Waterloo, ON, Canada. Electronic address:
Wild-caught fish are an important subsistence food source in remote northern regions, but they can also be a source of exposure to mercury (Hg), which has known health hazards. We investigated factors and mechanisms that control variability of Hg concentrations in Lake Whitefish (Coregonus clupeaformis) among remote subarctic lakes in Northwest Territories, Canada. Integrating variables that reflect fish ecology, in-lake conditions, and catchment attributes, we aimed to not only determine factors that best explain among-lake variability of fish Hg, but also to provide a whole-ecosystem understanding of interactions that drive among-lake variability of fish Hg.
View Article and Find Full Text PDFSci Total Environ
January 2025
College of Marine Sciences, South China Agricultural University, Guangzhou 510642, China. Electronic address:
Mangrove ecosystem has attracted global attention as a hotspot for mercury (Hg) methylation. Although numerous biotic and abiotic parameters have been reported to influence methylmercury (MeHg) production in sediments, the key factors determining the elevated MeHg levels in mangrove wetlands have not been well addressed. In this study, Hg levels in the sediments from different habitats (mudflats, mangrove fringe, and mangrove interior) in the Futian mangrove wetland were investigated, aiming to characterize the predominant factors affecting the MeHg production and distinguish the key microbial taxa responsible for Hg methylation.
View Article and Find Full Text PDFEnviron Int
January 2025
IRD, Univ Brest, CNRS, Ifremer, LEMAR, IUEM, F-29280 Plouzané, France.
Humans are exposed to toxic methylmercury mainly by consuming marine fish, in particular top predator species like billfishes or tunas. In seafood risk assessments, mercury is assumed to be mostly present as organic methylmercury in predatory fishes; yet high percentages of inorganic mercury were recently reported in marlins, suggesting markedly different methylmercury metabolism across species. We quantified total mercury and methylmercury concentrations in muscle of four billfish species from the Indian and the Pacific oceans to address this knowledge gap.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Chongqing Vocational Institute of Engineering, Chongqing 402260, China.
Seasonally inundated areas (SIA) within aquatic systems are characterized by elevated methylmercury (MeHg) production. Nevertheless, the response characteristics of dissolved organic matter (DOM) quality in SIA sediments, including its molecular compositions and structure, and their impacts on the MeHg production are not yet fully understood. This research gap has been addressed through field investigations and microcosm experiments conducted in a metal-polluted plateau wetland.
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