Populations have always been exposed to high arsenic levels in food, drinking water, wine, and other sources. Arsenic is abundant in seafood, but in an organic form, arsenobetaine, that is not toxic and rapidly absorbed and excreted in the urine and bile.
Exposure to inorganic arsenic in drinking water is associated with health risks related to the duration and level of exposure, particularly above 300 ppb. Acute poisoning is associated with vomiting, bloody diarrhea, abnormal heart rhythm, esophageal and abdominal pain, and sometimes death because of cardiopulmonary collapse. Classical syndromes of chronic arsenic exposure include hyperkeratosis, corns, and warts on the feet (blackfoot) and hands.
In contrast to adverse effects of arsenic, small amounts of the metal may be essential to the body. Approximately 10 to 50 ppb might be necessary to maintain homeostasis of the body.