The primary sources of selenium in the environment are geologic and industrial. Selenium closely resembles sulfur chemically, and sulfur or sul­fide deposits of bismuth, copper, iron, lead, mercury, silver, and zinc ...

Hexachlorobenzene is a commercially produced chemical of high annual tonnage production used as a feedstock for many chemical manufacturing processes. It is a chemical listed by the U.S., Environmental Protection Agency ...

The primary source of 2,4,5-trichlorophenol (2,4,5-TCP) contamination in the environment is industrial effluents. The compound itself is used as a germicide and also as a reagent in the synthesis of certain herbicides, ...