The possible interference of
hexachlorobenzene and
octachlorostyrene (i.e., thermal byproducts from
hexachloroethane in
aluminum degassing) with
porphyrin metabolism was investigated in exposed workers. Urine specimens from 9 male
aluminum foundry workers (i.e., smelters) at 6 different companies and from 18 controls-matched for sex, age, residence, and socioeconomic status-were analyzed for total
porphyrins and
porphyrin isomers. Workers exposed to
hexachlorobenzene and
octachlorostyrene had a statistically significant increase in urinary total
porphyrins, compared with controls (mean +/- standard deviation: 13.63 +/- 11.13 micromol/mol
creatinine and 6.24 +/- 3.84 micromol/mol
creatinine, respectively; p = .02). The authors attributed the results mainly to differences in excretion of
coproporphyrins-notably
coproporphyrin III. Erythrocyte
uroporphyrinogen decarboxylase activity was similar in both groups. There was a high correlation between levels of
hexachlorobenzene and
octachlorostyrene, respectively, in plasma and urinary excretion of
porphyrins; these findings, however, relied heavily on 1 subject for whom extreme values were obtained. The results indicated that occupational exposure to
hexachlorobenzene and
octachlorostyrene in
aluminum degassing with
hexachloroethane may affect
porphyrin metabolism in a manner consistent with early secondary coproporphyrinuria-the first recognized step in the development of chronic
hepatic porphyria. It was also noted that changes remained detectable some years after exposure ceased.