Arsenic-laced water ups TB risk: report
http://www.nlm.nih.gov/medlineplus/news/fullstory_107366.html
http://www.nlm.nih.gov/medlineplus/news/fullstory_107366.html
"New evidence from a region in Chile with a history of arsenic contamination in drinking water suggests the chemical may have a surprising effect: tuberculosis (TB)."