Battle wages over selenium levels in war over mountain top removal in WV.

Anna Sale of West Virginia Public Broadcasting recently aired a story on a new front in the battle over mountain removal involving selenium and deformities in fish.  According to the news cast, a human health and environmental problem occurs when earth is disturbed with practices like mountaintop-removal mining.  Selenium builds up in water and then moves up the food chain.  The news story is found at http://www.wvpubcast.org/newsarticle.aspx?id=1920.  We expect this same battle will  be waged in eastern Kentucky where moutain top removal is used to mine coal.

 

Some background on selenium may be helpful to understand the concern over selenium building up in the waterways in West Virginia.  In its pure form, selenium exists as metallic gray to black hexagonal crystals, but in nature it is usually combined with sulfide or with silver, copper, lead, and nickel minerals. Selenium is often associated with organic-rich deposits including coal and black shale, both of which are present in the Pennsylvanian-age rocks that occur at or near the surface in the Appalachian Plateaus province. Available data on the geochemistry of Pennsylvanian-age coal beds show that those very beds that are included in the mountaintop mining sequence (Clarion, Brookville, No. 5 block, Stockton, Coalburg, and Winifrede) have high concentrations of selenium.  For example, median concentrations in these coal beds range from about 4.5 to 7 PPM and concentrations exceeding 10 PPM have been observed.  

 

Selenium is a trace mineral that is essential to good health for animals and humans, but required only in small amounts.  Selenium is incorporated into proteins to make selenoproteins, which are important antioxidant enzymes. The antioxidant properties of selenoproteins help prevent cellular damage from free radicals. Free radicals are natural by-products of oxygen metabolism that may contribute to the development of chronic diseases such as cancer and heart disease. Other selenoproteins help regulate thyroid function and play a role in the immune system. 

 

About 25 different selenoproteins have so far been observed in human cells and tissues. Because a lack of selenium deprives a cell’s ability to synthesize selenoproteins, many health effects of low selenium intake are believed to be caused by the lack of one or more specific selenoproteins.  However, too much selenium in one’s diet causes toxic effects and often leads to selenium poisoning. The threshold between essential and toxic concentrations of this element is rather narrow (the factor is in the range of 10-100).  Plant foods are the major dietary sources of selenium in most countries throughout the world. The content of selenium in food depends on the selenium content of the soil where plants are grown or animals are raised.  

 

According to U.S. EPA, the human health effects from selenium are:  

 

Short-term exposure: Selenium is an essential nutrient at low levels. However, U.S. EPA has found selenium to potentially cause the following health effects when people are exposed to it at levels above the MCL for relatively short periods of time: hair and fingernail changes; damage to the peripheral nervous system; fatigue and irritability.

 

Long-term exposure: Selenium has the potential to cause the following effects from a lifetime exposure at levels above the MCL: hair and fingernail loss; damage to kidney and liver tissue, and the nervous and circulatory systems.

 

Selenium is regulated by the Safe Drinking Water Act and enforceable standard called a Maximum Contaminant Level (MCL) is 0.05 PPM. The Safe Drinking Water Act was originally passed by Congress in 1974 to protect public health by regulating the nation’s public drinking water supply. The law was amended in 1986 and 1996 and requires many actions to protect drinking water and its sources: rivers, lakes, reservoirs, springs, and ground water wells. The Safe Drinking Water Act does not regulate private wells which serve fewer than 25 individuals.