Arsenic interrupts some of your body’s most basic and common biochemical pathways. Arsenic, particularly As³⁺ and As⁵⁺ oxides, interferes with the citric acid cycle and respiration (specifically reduction of NAD+ and ATP synthesis—see “Biochemistry”). If that weren’t enough to kill you, and it probably is, arsenic also boosts the level of hydrogen peroxide in your body, which causes another whole set of problems. Unfortunately, these toxic forms of arsenic are not only water soluble but can be found in well water from natural sources and man-made contamination from mining.