Amounts leading to toxicity: The average intake of mercury varies with location and diet. It may range from 10 mcg. to more than 500 mcg., mainly depending on air contamination. Industrial cities and heavily sprayed farmland have the highest levels. The average overall daily intake is probably about 30-50 mcg. Most humans can process at least that much daily without any problems.

Blood levels of mercury should be below .02 ppm, while hair levels may be higher, up to about 3-5 ppm. More than 5 ppm becomes a concern. When these levels are exceeded, we should look for the sources of increased exposure and work toward avoiding or eliminating them.

Who is susceptible? Anyone working with mercury, especially methyl or ethyl mercury or mercuric chloride, is more likely to have problems of mercury toxicity. Farmers using mercury products should be very careful with them and should be aware of mercury toxicity symptoms or have mercury levels checked every couple of years.

Treatment of toxicity: Drinking milk helps reduce the acute effects of mercury, as the mercury will act on the protein in the milk instead of on the stomach and intestinal lining. This may prevent the acute symptoms of gastrointestinal tissue irritation, such as vomiting and bleeding.

Penicillamine is a chelating drug that can pull mercury out of the circulation. It works best when given soon after exposure, rather than after tissue storage occurs. Penicillamine itself, however, is potentially toxic. Dimercaprol (BAL) has also been used. EDTA,