TOXICOLOGICAL AND IMMUNE FINDINGS IN WORKERS EXPOSED TO PENTACHLOROPHENOL (PCP)

Pentachlorophenol (PCP) is a pesticide used worldwide in industrial an d domestic applications. Data available on the effects of technical-gr ade PCP on the immune system are insufficient and equivocal; some data indicate inhibitory effects, whereas others suggest stimulating effec ts. This study was performed to evaluate toxicological and immune find ings in 32 subjects who had prolonged exposure to PCP in a wood factor y and in 37 controls. PCP concentrations were determined in plasma and urine of all subjects. Lymphocyte subsets of CD3-, CD4-, and CD8-posi tive cells were evaluated, and the proliferative response of periphera l blood mononuclear cells (PBM) to mitogens was assessed. The results suggested the absence of major laboratory and clinical signs of PCP-de pendent immune deficiency. A weak effect of long-term exposure to PCP on the functional immune response could not be ruled out because of th e finding of a decreased response to 5% PHA in the high-exposure group . A weak effect against hepatocyte membrane was evidenced by the findi ng of raised serum concentration of glycocholic, taurodeoxycholic, and glycochenodeoxycholic acids in subjects directly exposed to PCP for m ore than 10 y.