Clinical and metabolic abnormalities associated with occupational exposure to polychlorinated biphenyls (PCBs)

A cross-sectional study of 120 male workers was conducted to determine the prevalence of increased polychlorinated biphenyl (PCB) absorption as well as the presence of potentially related clinical and metabolic abnormalities. Three exposure categories ("exposed", "nominally exposed", "nonexposed") were defined. Complete work histories, clinical histories, physical examinations and laboratory tests, including plasma PCB determinations were obtained. In addition, fat PCB levels were determined in randomly selected subjects in each exposed group. Evidence of dermatotoxicity was observed and elevated PCB levels were noted more frequently in the exposed group (p less than .0001), correlating well with age and duration of employment. These correlations were stronger for fat (p less than .001) than for plasma (p less than .01) PCB levels. In the exposed group, significant correlations were found between plasma PCB and serum triglyceride (p less than .0001) and serum glutamic oxaloacetic transaminase (SGOT) levels (p less than .01). These correlations remained significant after controlling for either age or length of employment. No significant correlations were found between PCB levels and levels of cholesterol, high-density lipoprotein cholesterol or levels studied on liver function tests other than SGOT. Further analyses relating frequency of reported direct contact with PCB levels suggested a dermal route of exposure. An analysis by union affiliation demonstrated that those in crafts involving greater direct exposure had correspondingly higher elevations of PCB levels.