Peripheral neuropathy after occupational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)

Abstract

Reports of human exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) describe signs and symptoms consistent with exposure-related peripheral neuropathy. In a cross-sectional study, prevalence of peripheral neuropathy was measured in 265 workers exposed 15 years earlier to chemicals contaminated with TCDD and in 244 unexposed, age-, race-, gender- and community-matched comparisons. Cases of peripheral neuropathy were defined from examination, electrophysiologic and quantitative sensory tests, and symptoms. Exposure was assessed by measuring lipid-adjusted serum TCDD levels. The mean serum TCDD level for workers (220 parts per trillion (ppt)) was significantly higher than for referents (7 ppt) (p < .0001). Thirty-two percent of both worker and referent groups met the case definition for peripheral neuropathy. In the logistic regression analyses, serum TCDD level was not related to peripheral neuropathy. These data suggest that despite continued high serum TCDD levels, 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.