A MORBIDITY STUDY OF FORMER PENTACHLOROPHENOL-PRODUCTION WORKERS

Pentachlorophenol (PCP) is a pesticide that was once widely used for w ood preservation. Commercial PCP contained impurities including higher chlorinated dibenzo-p-dioxins (CDDs) and chlorinated dibenzofurans (C DFs). We investigated the effects of occupational exposure to PCP and its CDD and CDF contaminants on the skin, liver, porphyin metabolism, and central and peripheral nervous systems. In 1986 we conducted a med ical survey of 366 workers who had been engaged in the production of P CP at a single plant between 1938 and 1978. The referent group consist ed of 303 workers from the same plant who were not exposed to these or related compounds. Exposure was determined from computerized personne l records. The medical survey included an administered questionnaire, medical record review, physical examination by dermatologists, interni sts, and neurologists, and analysis of 24-hr urine for quantitative po rphyrins among other tests. In this paper we present the results of an alyses of the general health, chloracne, and porphyrin metabolism end points. The general health status of PCP workers was similar to unexpo sed workers, but 17.8% of PCP workers had evidence of current or past chloracne. PCP workers with chloracne had significantly higher mean ur inary excretion of coproporphyrins (117.0 vs. 90.6 mu g/24 hr) than un exposed workers after controlling for potential confounders. Workers w ith chloracne who had worked with both PCP and polychlorinated bipheny ls had significantly higher mean urinary excretions of hepta-, penta-, and coproporphyrins than unexposed workers. We conclude that occupati onal exposure to PCP is associated with chloracne and biochemical abno rmalities which may persist years after exposure.