Neurological effects of environmental exposure to arsenic in dust and soilamong humans

Persons living in a small town in Georgia, USA, were studied because of kno wn environmental exposure to arsenic-containing dust. To assess the effects of this exposure on the nervous system, a cross-sectional epidemiological study was performed. The health outcome assessments of the study were based on a priori selected clinical examination results and quantitative electro physiologic and behavioral outcome measures. Because the primary goal was t o identify cases of peripheral neuropathy, a clinically relevant case defin ition, based on results of these outcomes was created. Historical exposure reconstructions were performed on a subset of the exposed subjects for whom such information was available. Of the 238 persons enrolled in the study, 133 were classified as non-exposed (i.e., did not reside in the area of kno wn exposure) and 105 were classified as exposed (i.e., did reside in the ar ea of known exposure). Following exclusions of persons with occupational ex posure to neurotoxicants, pre-existing conditions associated with periphera l nerve impairment, or age below 18 years, 118 unexposed subjects and 85 ex posed subjects were available for inclusion in the analyses of peripheral n erve outcomes. A total of 4 (3.4%) of the unexposed subjects and 13 (15.3%) of the exposed subjects met the case definitions for peripheral neuropathy (OR=5.1; p=0.004). Comparison of three exposure groups (none, low, high) d id not yield statistically significant differences. Statistically significa nt exposure group differences were observed on quantitative tests of standi ng steadiness, vibrotactile threshold and tremor intensity but not for nerv e conduction measures. These results demonstrate a strong association betwe en community arsenic containing dust exposure and peripheral neuropathy amo ng participants in this investigation. (C) 2000 Intox Press, Inc.