ToxSci Advance Access originally published online on April 1, 2009
Toxicological Sciences 2009 109(2):296-305; doi:10.1093/toxsci/kfp063
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Neurobehavioral Effects of Acute Exposure to Four Solvents: Meta-analyses
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* Human Studies Division, Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711
Department of Psychology, University of North Carolina, Chapel Hill, North Carolina
Neurotoxicology Division
Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711
1 To whom correspondence should be addressed at Human Studies Division, Mail Code B105-06, US Environmental Protection Agency, Research Triangle Park, NC 27711. Fax: (919) 541-4849. E-mail: benignus.vernon{at}epa.gov.
Received February 2, 2009; accepted March 20, 2009
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Abstract |
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Meta- and reanalyses of the available data for the neurobehavioral effects of acute inhalation exposure to toluene were reported by Benignus et al. The present study was designed to test the generality of the toluene results in as many other solvents as possible by further meta- and reanalyses. Sufficient data for meta-analyses were found for only four solvents; toluene, trichloroethylene, perchloroethylene, and 1,1,1-trichloroethane. The results for these solvents showed that rats were less affected by each of the solvents when they were tested in highly motivating situations, for example, rewarded for rapid or correct responding or escape from electrical shock, compared with less motivating circumstances. The four solvents did not differ significantly in potency on any outcome measure when dose was expressed as molar brain concentration. When tested in tasks with low-motivational contingencies, the dose-effect curves of humans (reaction times) and rats (electrophysiological responses to visual stimuli) were not significantly different. However, on an exploratory follow-up analysis, humans were less sensitive than rats. No human data were found to test whether species differed under strong motivation. Dose-equivalence curves were derived for extrapolating to human effects from rat data.
Key Words: toxicity; acute nervous system; volatile organic compounds.
This manuscript has been reviewed by the National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, and approved for publication. Approval does not signify that the contents necessarily reflect the policies of the agency nor does mention of trade names or commercial products constitute endorsement or recommendation for use.