Long-Term Effects of 2,3,7,8-Tetrachlorodibenzo-<i>p</i>-Dioxin on the Peripheral Nervous System

Abstract

This work was set up to investigate the possible presence of peripheral nervous system involvement as a long-term effect of the exposure to dioxin in 152 subjects with chloracne from the Seveso area; 123 age- and sex-matched subjects living in nearby towns with similar environmental pollution formed the control group. The accident in Seveso took place in July, 1976, and this study was carried out from October, 1982, to May, 1983. Although a peripheral neuropathy was not found in any of the subjects, a significant increase of the number of individuals presenting at least two bilateral clinical signs (p < 0.05) or one abnormal electrophysiological parameter (p < 0.02) was found in the Seveso group. Principal component analysis did not show any subdivision between these two groups. The Fisher approach to discriminant analysis reveals a clear subdivision between the group of the most exposed subjects and randomly selected subgroups of control subjects. In conclusion, clinical and electrophysiological signs of peripheral nervous system involvement occur with a statistically increased frequency in the Seveso population 6 years after the accident, although a peripheral neuropathy was not evident in any of the chloracne patients using the World Health Organization diagnostic criteria.

Histologic evidence for a toxic polyneuropathy due to exposure to 2,3,7,8 - tetrachlorodibenzo-p-dioxin (TCDD) in rats

“…However, data on peripheral nervous system affections are sparse and not conclusive. Barbieri and co-workers investigated 152 exposed subjects from the Seveso area 6 years after the chemical accident (10). They found some clinical and electrophysiological signs of peripheral nerve affection.…”

Reflections on the assessment of the toxicity of “dioxins” for humans, using data from experimental and epidemiological studies

“…Studying Seveso residents, clinical and electrophysiological signs of peripheral nervous system involvement were observed [139], but no peripheral neuropathy according to the WHO criteria. No clinical or electrophysiological signs of peripheral neuropathy were reported in 193 persons with chloracne 9 years after the Seveso accident [61].…”

Cranial nerve function in workers exposed to polychlorinated dioxins and furans

“…Workers with chloracne have an increased risk to develop peripheral nerve dysfunction as shown by a number of studies mainly reporting a distal symmetric sensory neuropathy in the legs (or more pronounced in the legs) (1–8). These studies are in accordance to experimental findings showing a dose‐related histologically and neurophysiologically proven axonal neuropathy after a single intraperitoneal injection of TCDD in rats (23, 24).…”

“…Polychlorinated dioxins and furans (PCDD/F) were repeatedly shown to cause peripheral nerve dysfunction (1–8). The manifestation is mainly as a distal symmetric sensory neuropathy in the legs (or more pronounced in the legs) in severely exposed persons.…”