PERIPHERAL NEUROPATHY AFTER OCCUPATIONAL EXPOSURE TO 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD)

Reports of human exposure to 2.3,7,8-tetrachlorodibenzo-p-dioxin (TCDD ) describe signs and symptoms consistent with exposure-related periphe ral neuropathy. In a cross-sectional study, prevalence of peripheral n europathy was measured in 265 workers exposed 15 years earlier to chem icals contaminated with TCDD and in 244 unexposed, age-, race-, gender - and community-matched comparisons. Cases of peripheral neuropathy we re defined from examination, electrophysiologic and quantitative senso ry tests, and symptoms. Exposure was assessed by measuring lipid-adjus ted serum TCDD levels. The mean serum TCDD level for workers (220 part s per trillion (ppt)) was significantly higher than for referents (7 p pt) (p < .0001). Thirty-two percent of both worker and referent groups met the case definition for peripheral neuropathy. In the logistic re gression analyses, serum TCDD level was not related to peripheral neur opathy. These data suggest that despite continued high serum TCDD leve ls, peripheral neuropathy is not a long-term sequela of high exposure to TCDD-contaminated chemicals. However, the study cannot preclude the occurrence and subsequent resolution of acute effects caused by high exposure, as experienced in Seveso and possibly by some workers, while exposed to high levels of TCDD-contaminated substances.