Arsenic And Selenium Fact Sheets and Technical Papers
The reports linked below are based on a comprehensive review of the scientific literature on arsenic and selenium in the environment. TVA commissioned the international scientific and engineering consulting firm Exponent to conduct the review and produce the reports. Arsenic and selenium are present in coal ash in very low concentrations (trace amounts), and these reports are intended to provide an understanding of the effects that arsenic and selenium could have on environmental and human health. The fact sheets and technical papers have been updated by Exponent since first being made available on this site, with the most recent information on arsenic and selenium incorporated into these reports.
Environmental conditions affect the chemical form of selenium, which in turn affects the mobility of selenium in the environment and its uptake by algae and microorganisms. Selenium can bioaccumulate in organisms at the base of the food web to levels that are toxic to their consumers, such as fish and birds. The reproductive system generally is the most sensitive to selenium toxicity. However, ecosystems and animal populations can recover rapidly, within several years, from selenium effects once selenium is removed.
The chemical form of arsenic determines its mobility and toxicity, and the form of arsenic is also affected by the environmental conditions. The chemical forms of arsenic in microorganisms, fish, and animals generally are less toxic or are not toxic to them, so human exposure to arsenic is the main concern. Exposure to coal ash or to arsenic leached from coal ash can occur through soil, water, and air pathways; and the main human health concern about arsenic is the development of cancer due to chronic long-term exposure. The normal estimated lifetime dose of arsenic from exposure to coal ash mixed with soil would be very similar to the levels of arsenic found in a person’s diet and water. TVA continues to monitor the Kingston-area ecosystem to determine if there are impacts caused by the trace levels of arsenic and selenium known to be in the coal ash.
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