Wiki: Selenium is a chemical element with symbol Se and atomic number 34. It is a nonmetal with properties that are intermediate between those of its periodic table column-adjacent chalcogen elements sulfur and tellurium. It rarely occurs in its elemental state in nature, or as pure ore compounds. Selenium (Greek σελήνη selene meaning "Moon") was discovered in 1817 by Jöns Jacob Berzelius, who noted the similarity of the new element to the previously known tellurium (named for the Earth).
Selenium is found impurely in metal sulfide ores, where it partially replaces the sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores, most often during copper production. Minerals that are pure selenide or selenate compounds are known, but are rare. The chief commercial uses for selenium today are in glassmaking and in pigments. Selenium is a semiconductor and is used in photocells. Uses in electronics, once important, have been mostly supplanted by silicon semiconductor devices. Selenium continues to be used in a few types of DC power surge protectors, baby formula, and one type of fluorescent quantum dot.
Why do I care about selenium? Because the topic is going to come up with respect to mountaintop coal mining in West Virginia. Hence, before the hysteria gets to strong, we should know a few things about it. In West Virginia, selenium drains into streams from coal mining, and kills a lot of fish. Consider the following toxic substance:
Polychlorinated biphenyls (PCBs) were widely used as dielectric and coolant fluids, for example in transformers, capacitors, and electric motors. Due to PCBs' environmental toxicity and classification as a persistent organic pollutant, PCB production was banned by the United States Congress in 1979 and by the Stockholm Convention on Persistent Organic Pollutants in 2001.[1] According to the U.S. Environmental Protection Agency (EPA), PCBs have been shown to cause cancer in animals, and there is also evidence that they can cause cancer in humans.[2]
Now pcbs are very bad indeed, a much small concentration and humans get cancer. PCB is a manmade combination of a petrochemical, benzene and chlorine. Now pcbs have been spilled, misused and have caused great harm. The chemical that Freedom industries spilled in West Virginia is likely nasty stuff, it is also a manmade organic compound, a solvent designed to clean coal. It spilled from a storage tank and Freedom industries will likely go bankrupt as a result.
Here is what you need to know. Large concentrations of selenium in fresh water makes selenium water in which fresh water fish cannot survive. But fresh water fish also are poisoned by salt water run off. Fresh water fish do not survive in the great Salt Lake of Utah. But selenium, like salt, is naturally occurring and generally harmless, like salt. So when the debate about selenium pollution begins remember, this is more a water cleanliness problem and less a real toxic issue.
The main problem in West Virginia, the one I would object to, is the back filling and damning of streams as a way to dispense excess dirt and rock from coal mining. I would like to see that stopped first, and worry the selenium second.
