A pilot study of serum polychlorinated biphenyl levels in persons at high risk of exposure in residential and occupational environments.

A pilot study was conducted to determine whether persons at high risk of exposure to three waste sites in the area of Bloomington, Indiana, have abnormally elevated serum polychlorinated biphenyl (PCB) levels. In addition, we attempted to determine which environmental pathways might have contributed most to these exposures. First, a screening questionnaire survey of 995 individuals was conducted; on the basis of these data, 114 of the persons who had the greatest potential for exposure were selected for inclusion in this pilot exposure assessment study. People near these waste sites have higher average serum PCB levels, and a greater percentage have abnormally elevated serum PCB levels, compared with previously characterized populations in the United States. However, we could not distinguish specific pathways of exposure and uptake, with the exception of persons with occupational exposures and, possibly, among persons who reportedly salvaged metal from discarded electrical equipment. Exposures in this community require further evaluation.