Neurophysiological and psychophysical measurements reveal effects of acute low-level organic solvent exposure in humans

Abstract

The organic solvent tetrachloroethylene (Per) is proposed to be a human neurotoxicant. In order to evaluate whether the sensory system is affected by Per at low concentrations, two groups of male volunteers were exposed in an inhalation chamber to 10 and 50 ppm Per, respectively. During the inhalation exposure, which lasted for 4 h per day on four consecutive days, visually evoked potentials (VEPs) and brainstem auditory evoked potentials (BAEPs) were measured. In addition, in some of these volunteers, the visual contrast sensitivity was determined psychophysically. In the group exposed to 50 ppm Per, the VEP peak latencies N75, P100 and N150 increased in the course of the inhalation period. A comparison of the two groups revealed statistically significant differences of these latency changes during Per exposure. In contrast, the BAEPs of the two groups did not differ significantly during the whole exposure period. The contrast sensitivity functions showed a tendency of increased threshold contrasts at low and intermediate spatial frequencies during exposure to 50 ppm Per. The results indicate visual system dysfunctions in terms of delayed neuronal processing time and altered contrast perception due to acute Per exposure.

Assessment of Neurophysiologic and Neurobehavioral Effects of Environmental Pollutants in 5- and 6-Year-Old Children

“…Alterations in VEPs have been reported, e.g., after exposure to organic solvents (Stewart et al, 1974;Altmann et al, 1990) and after occupational exposure to mercury vapor (Ellingsen et al, 1993). Chemicals such as acrylamide and methyl mercury have been shown to reduce the CS (Merigan et al, 1985(Merigan et al, , 1988.…”

Response to letter from J.E. Storm and colleagues concerning the paper “Review of the epidemiologic literature on residential exposure to perchloroethylene”

“…There are actually a relatively substantial number of occupational studies and controlled-chamber experiments suggesting that subtle neurobehavioral effects from PERC have a threshold of approximately 10-25 ppm (68-170 mg/m 3 ). For example, male volunteers undergoing controlled exposure to either 68 mg/ m 3 or 340 mg/m 3 PERC showed significant changes in visually evoked potentials and on some neurobehavioral tests at the higher exposure, but not at the lower one (Altmann et al, 1990;1992). Limited data on VCS testing suggested decrements at the high exposure, but improvements at the lower one (Altmann et al, 1990).…”

“…For example, male volunteers undergoing controlled exposure to either 68 mg/ m 3 or 340 mg/m 3 PERC showed significant changes in visually evoked potentials and on some neurobehavioral tests at the higher exposure, but not at the lower one (Altmann et al, 1990;1992). Limited data on VCS testing suggested decrements at the high exposure, but improvements at the lower one (Altmann et al, 1990). Occupational studies similarly suggest a threshold of perhaps 68-136 mg/m 3 for subtle neurosensory changes (Bukowski, 2011).…”

Tetrachloroethylene exposure and risk of schizophrenia: Offspring of dry cleaners in a population birth cohort, preliminary findings

“…It has been reported to have neurotoxic effects in animals (Wang et al 1993). Neurobehavioral deficits have been reported in people living near a dry cleaning facility (Altmann et al 1995) and PCE exposure may disturb neuronal processing and alter visual function (Altmann et al 1990). …”