According to animal research by University of Pittsburgh scientists set to be published in the December issue of the Journal of Clinical Investigation, and available online now at http://www.jci.org/articles/view/35092 , arsenic at EPA-approved levels for drinking water causes pores in liver blood vessels to close, potentially leading to cardiovascular disease and hypertension.
… Rural (so-called Red States) are prime targets for the death dealers at the EPA: The current federal standard for arsenic in public water systems not only may be too high, but it only applies to drinking water sources that serve more than 20 people.