Mercury (Hg) inputs have particularly impacted the northeastern United States due to its proximity to anthropogenic emissions sources and abundant habitats that efficiently convert inorganic Hg into methylmercury. Intensive research and monitoring efforts over the past 50 years in New York State, USA, have informed the assessment of the extent and impacts of Hg exposure on fishes and wildlife. By synthesizing Hg data statewide, this study quantified temporal trends of Hg exposure, spatiotemporal patterns of risk, the role that habitat and Hg deposition play in producing spatial patterns of Hg exposure in fish and other wildlife, and the effectiveness of current monitoring approaches in describing Hg trends.
View Article and Find Full Text PDFMercury methylation frequently occurs at the active oxic/anoxic boundary between the sediment bed and water column of lakes and reservoirs. Previous studies suggest that the predominant mercury methylation zone moves to the water column during periods of stratification and that high potential methylation rates (K) in sediment require oxygenated overlying water. However, simultaneous measurements of methylmercury (MeHg) production in both the sediment and water column remain limited.
View Article and Find Full Text PDFAcid deposition has declined across eastern North America and northern Europe due to reduced emissions of sulfur and nitrogen oxides. Ecosystem recovery has been slow with limited improvement in surface water chemistry. Delayed recovery has encouraged acid-neutralization strategies to accelerate recovery of impaired biological communities.
View Article and Find Full Text PDFIn the mid-2000s a survey was conducted to evaluate fish mercury in lakes across New York State. Approximately 10 years later a second survey examining adult sportfish from 103 lakes and reservoirs was conducted to evaluate the response of fish mercury to recent declines in US mercury emissions. Of those lakes, 43 were part of the earlier survey and were examined to determine if mercury concentrations in four popular sport species, Yellow Perch, Walleye, and Small- and Largemouth Bass, declined in response to decreasing emissions.
View Article and Find Full Text PDFSurface waters in Europe and North America previously impacted by acid deposition are recovering in conjunction with declining precursor emissions since the 1980s. Lime has been applied to some impacted watersheds to accelerate recovery. The response to liming can be considered a proxy for future recovery from acid deposition.
View Article and Find Full Text PDFWe estimated for Australia the number of cases, hospitalizations, and deaths due to foodborne gastroenteritis in a typical year, circa 2000. The total amount of infectious gastroenteritis was measured by using a national telephone survey. The foodborne proportion was estimated from Australian data on each of 16 pathogens.
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