Seasonal arsenic exposure from burning chromium-copper-arsenate-treated wood.

All eight members of a rural Wisconsin family experienced recurring neurological and medical illness over three years, especially during the winter months. Arsenic, in concentrations of 12 to 87 ppm, was noted in the hair of the mother and father, and analysis of hair and fingernails of all family members demonstrated pathological levels of arsenic. For four years the five-room home had been heated with a small wood stove in which outdoor or marine plywood and wood remnants had been preferentially burned. Stove ashes that contained more than 1,000 ppm of arsenic contaminated the living area, and the ratio of copper, chromium, and arsenic pentoxide in this ash matched the ratio used in the chromium-copper-arsenate-treated wood.