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The human use of toxic heavy metals is here to stay. In addition to intentional poisoning with arsenic (40)(arsenic levels in the hair of Napoleon Bonaparte approached 40 ppm, more than 1,000 times above allowable levels), medical, agricultural, and industrial uses of arsenic present major human problems (5, 40, 41). Arsenic catastrophes are occurring today, most notably as the high arsenic levels present in drinking water in East Bengal and West Bengal, where over 40 million people are being exposed to more than 50 ppb of arsenic (8); this level was the limit accepted by the World Health Organization before that organization (and later the US government) set the allowable limit fivefold lower, at 10 ppb. Bangladesh maintains an allowable limit of 50 ppb, and the limit in Canada is 25 ppb. The arsenic found in Bengalese drinking water is present naturally in the sediment but is released only by humans, primarily …