Toward a Better Understanding of Mercury Emissions from Soils

Author(s):  
Hong Zhang ◽  
Steve Lindberg ◽  
Mae Gustin ◽  
Xiaohong Xu
Keyword(s):  
Author(s):  
Jonathan M Gendzier

Exposure to organic mercury (methylmercury) occurs almost universally due to ingestion via contaminated fish and shellfish tissue. Ultimate sources of mercury consist of air release by domestic industrial combustion, mining, and international mercury emissions transported via a global cycle. Deposition of mercury from air to surface waters results in methylation to organic methylmercury and bioaccumulation in the aquatic food web. Health effects from methylmercury exposure consist mainly of neurological and neurodevelopmental effects, with fetuses particularly sensitive. Thus regulation of methylmercury exposure has concentrated on acceptable exposure levels and reference doses aimed toward protecting developing fetuses. The risk of methylmercury exposure in humans is regulated largely by the federal government, especially by the Environmental Protection Agency (EPA) and the Food and Drug Administration (FDA). The EPA imposes limits on mercury emissions and seeks to research methylmercury levels in fish and humans. The EPA sets a reference dose for methylmercury exposure. The FDA conducts uses date on methylmercury levels in fish to advise consumers on how to make informed decisions regarding fish consumption. There are numerous shortcoming to government regulation of this issue. Further scientific research, improved implementation of available data and scientific conclusions, and improved public communication of risk would all lead to more effective treatment of the risk of methylmercury exposure via ingestion of fish and shellfish. This could include more effective monitoring systems of human and fish methylmercury levels, research into the process of bioaccumulation, and implementation of stricter fish labeling standards, as well as research into higher-risk subpopulations allowing for targeted standards and recommendations.


2021 ◽  
pp. 125060
Author(s):  
Yaqin Guo ◽  
Lin Xiao ◽  
Bin Chen ◽  
Zhujuan Wu ◽  
Huanxin Chen ◽  
...  

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2361
Author(s):  
Yinjiao Su ◽  
Xuan Liu ◽  
Yang Teng ◽  
Kai Zhang

Coal combustion is an anthropogenic source of mercury (Hg) emissions to the atmosphere. The strong toxicity and bioaccumulation potential have prompted attention to the control of mercury emissions. Pyrolysis has been regarded as an efficient Hg removal technology before coal combustion and other utilization processes. In this work, the Hg speciation in coal and its thermal stability were investigated by combined sequential chemical extraction and temperature programmed decomposition methods; the effect of coal rank on Hg speciation distribution and Hg release characteristics were clarified based on the weight loss of coal; the amount of Hg released; and the emission of sulfur-containing gases during coal pyrolysis. Five species of mercury were determined in this study: exchangeable Hg (F1), carbonate + sulfate + oxide bound Hg (F2), silicate + aluminosilicate bound Hg (F3), sulfide bound Hg (F4), and residual Hg (F5), which are quite distinct in different rank coals. Generally, Hg enriched in carbonates, sulfates, and oxides might migrate to sulfides with the transformation of minerals during the coalification process. The order of thermal stability of different Hg speciation in coal is F1 < F5 < F2 < F4 < F3. Meanwhile, the release of Hg is accompanied with sulfur gases during coal pyrolysis, which is heavily dependent on the coal rank.


2008 ◽  
Vol 42 (22) ◽  
pp. 8564-8570 ◽  
Author(s):  
Matthew J. Eckelman ◽  
Paul T. Anastas ◽  
Julie B. Zimmerman

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