4. iAs continues to poison the drinking water of tens of millions of people around the world

5. >63,000 wells over 10 yrs Max=800 ppb 1436 wells contaminated above 10 ppb Hundreds exceeded 50 ppb >63,000 wells over 10 yrs Max=800 ppb 1436 wells contaminated above 10 ppb Hundreds exceeded 50 ppb More than 2.3 million people in North Carolina use water from private, unregulated wells Sanders et al 2011 Data from 2009

6. Sanders et al 2011 Data from 2009 75,000 people More than 2.3 million people in North Carolina use water from private, unregulated wells >63,000 wells over 10 yrs Max=800 ppb 1436 wells contaminated above 10 ppb Hundreds exceeded 50 ppb >63,000 wells over 10 yrs Max=800 ppb 1436 wells contaminated above 10 ppb Hundreds exceeded 50 ppb

11. Cytochrome c oxidase The enzyme cytochrome c oxidase or Complex IV) is a large transmembrane protein complex found in bacteria and the mitochondrion. The complex contains two hemes a cytochrome a and cytochrome a 3, and two copper centers, the Cu A and Cu B centers

16. 1

17. 2

18. 3

22. Cd and Zn transporters

23. Methylmercury and methionine

32. Monovalent, divalent

36. elemental inorganic

43. Inhibits ability to make hemoglobin

50. Cr(VI) is generally considered 1,000 times more toxic than Cr(III) [EPA 1998; ATSDR 2000; Dayan and Paine 2001].

51. The toxicity of chromium compounds depends on the oxidation state of the metal. Occupational exposure to chromium(VI) compounds has been associated with increased incidence of lung cancer. Chromium(III) is an essential nutrient that can be toxic in large doses.