Hexachlorobenzene contamination: its effects in a Louisiana population.

Plasma hexachlorobenzene (HCB) residues in a Louisiana population exposed through the transportation and disposal of chemical waste containing HCB averaged 3.6 plus or minus 4.3 parts per billion (ppb) in a sample of 86 people. The highest level was 345 ppb in a waste disposal facility worker while the highest level in the general population was 23 ppb. There was no evidence of cutaneous porphyria by history or skin examination. Males had significantly higher residues than females (4.71 vs. 2.79 ppb) but there were no age differences. A possible association between HCB residues and coproporphyrin and lactic dehydrogenase was found. Only 2 of 48 meals sampled were positive for HCB. There was a correlation between HCB levels in household dust and plasma levels. Perchloroethylene and carbon tetrachloride production workers had plasma HCB levels of up to 233 ppb.