The Arsenic in Our Drinking Water
The element is naturally occurring arsenic, which swirls in a dark, metalloid shimmer in soil and rock across much of the United States and in many other countries. It seeps into groundwater, but because the contamination tends to be minor in this country, for many years its presence was mostly noted and dismissed by public health researchers.
They’ve changed their minds. Long famed for its homicidal toxicity at high doses, a number of studies suggest that arsenic is an astonishingly versatile poison, able to do damage even at low doses. Chronic low-dose exposure has been implicated not only in respiratory problems in children and adults, but in cardiovascular disease, diabetes and cancers of the skin, bladder and lung.
Article continues: http://well.blogs.nytimes.com/2013/09/20/the-arsenic-in-our-drinking-water/?ref=health