Journal ArticleDOI
Distribution of total mercury and methyl mercury in water, sediment, and fish from south Florida estuaries.
Kurunthachalam Kannan,Ralph G. Smith,Richard F. Lee,H. L. Windom,P.T. Heitmuller,John M. Macauley,J. K. Summers +6 more
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TLDR
The relationship of total and methyl mercury concentrations in fish to those of sediments from corresponding locations was fish-species dependent, in addition to several abiotic factors, and among fish species analyzed, hardhead cat fish, gafftopsail catfish, and sand seatrout contained the highest concentrations of mercury.Abstract:
Concentrations of total mercury and methyl mercury were determined in sediment and fish collected from estuarine waters of Florida to understand their distribution and partitioning. Total mercury concentrations in sediments ranged from 1 to 219 ng/g dry wt. Methyl mercury accounted for, on average, 0.77% of total mercury in sediment. Methyl mercury concentrations were not correlated with total mercury or organic carbon content in sediments. The concentrations of total mercury in fish muscle were between 0.03 and 2.22 (mean: 0.31) μg/g, wet wt, with methyl mercury contributing 83% of total mercury. Methyl mercury concentrations in fish muscle were directly proportional to total mercury concentrations. The relationship of total and methyl mercury concentrations in fish to those of sediments from corresponding locations was fish-species dependent, in addition to several abiotic factors. Among fish species analyzed, hardhead catfish, gafftopsail catfish, and sand seatrout contained the highest concentrations of mercury. Filtered water samples from canals and creeks that discharge into the Florida Bay showed mercury concentrations of 3–7.4 ng/L, with methyl mercury accounting for <0.03–52% of the total mercury. Consumption of fish containing 0.31 μg mercury/g wet wt, the mean concentration found in this study, at rates greater than 70 g/day, was estimated to be hazardous to human health.read more
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Environmental threats and environmental future of estuaries
TL;DR: Detailed examination of the effects of pollution inputs, the loss and alteration of estuarine habitat, and the role of other anthropogenic stress indicates that water quality in estuaries, particularly urbanized systems, is often compromised by the overloading of nutrients and organic matter, the influx of pathogens and the accumulation of chemical contaminants.
Journal ArticleDOI
Mass-Dependent and -Independent Fractionation of Hg Isotopes by Photoreduction in Aquatic Systems
TL;DR: Large variations in MDF and MIF are observed in fish and provide new insights into the sources and bioaccumulation of Hg in food webs and the loss of methylmercury via photoreduction in aquatic ecosytems.
Journal ArticleDOI
Blood organic mercury and dietary mercury intake: National Health and Nutrition Examination Survey, 1999 and 2000.
TL;DR: Based on the distribution of BHg concentrations among the adult female participants in 1999-2000 NHANES and the number of U.S. births in 2000, > 300,000 newborns each year in the United States may have been exposed in utero to methyl mercury concentrations higher than those considered to be without increased risk of adverse neurodevelopmental effects associated with methyl mercury exposure.
Journal ArticleDOI
Role of the bacterial organomercury lyase (MerB) in controlling methylmercury accumulation in mercury-contaminated natural waters
Jeffra K. Schaefer,Jane Yagi,John R. Reinfelder,Tamara Cardona,Kristie M. Ellickson,Shoshana Tel-Or,Tamar Barkay +6 more
TL;DR: The results strongly support the hypothesis that the degradation of MeHg by mer-encoded enzymes by the water column microbiota of contaminated environments can significantly affect the amount of Mehg that is available for entry into the aquatic food web.
Journal ArticleDOI
Mercury methylation in estuaries: Insights from using measuring rates using stable mercury isotopes
TL;DR: In this article, rates of methylation and demethylation in sediment of the Hudson River, Chesapeake Bay and Bay of Fundy were measured using stable isotopes of mercury (Hg) and methylmercury (MeHg).
References
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Journal ArticleDOI
Comparison of distillation with other current isolation methods for the determination of methyl mercury compounds in low level environmental samples: Part 1. Sediments
TL;DR: In this paper, two isolation procedures for the separation of methyl mercury compounds (MeHg) from natural water samples, followed by aqueous phase ethylation, precollection on the Carbotrap, isothermal gas chromatography and cold vapour atomic fluorescence (CV-AFS) detection were compared and evaluated.
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Mercury methylation in aquatic systems affected by acid deposition
TL;DR: This work focuses on the hypothesis that sulfate-reducing bacteria are important mediators of metal methylation in aquatic systems and, moreover, that sulfATE-deposition may stimulate methylmercury production by enhancing the activity of sulfate, reducing bacteria in sediments.
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Factors affecting mercury accumulation in fish in the upper michigan peninsula
Thomas M. Grieb,George L. Bowie,Charles T. Driscoll,Steven P. Gloss,Carl L. Schofield,Donald B. Porcella +5 more
TL;DR: In this paper, fish were sampled from 35 drainage and seepage lakes in the upper Michigan peninsula and Wisconsin in conjunction with Phase II of the U.S. Environmental Protection Agency's Eastern Lake Survey to explore the relationship between physicochemical characteristics of lakes and mercury concentrations in fish tissue.
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Environmental distribution and transformation of mercury compounds
TL;DR: In this article, the authors provide a comprehensive evaluation of the chemical and physical processes that govern mercury distribution among the major environmental media, including physicochemical properties, partition coefficients, and intermedia transport parameters.