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Biofuels health research at the EPA: Initial studies with inhaled ethanol in rats.
Citation:
BUSHNELL, P. J., T. E. BEASLEY, W. K. BOYES, H. A. EL-MASRI, P. A. EVANSKY, J. Ford, D. W. HERR, W. R. Lewfew, S. A. Martin, K. MCDANIEL, M. E. GILBERT, E. MCLANAHAN, D. K. MacMillian, V. C. MOSER, AND W. M. OSHIRO. Biofuels health research at the EPA: Initial studies with inhaled ethanol in rats. Presented at Society of Toxicology (SOT) Annual Meeting, Washington, DC, March 06 - 10, 2011.
Impact/Purpose:
Potential neurological and immunological effects from developmental exposure to evaporative emissions from ethanol-gasoline blends are particular concerns. We have therefore begun a research effort involving computational modeling and animal experimentation, with the goal of estimating quantitatively the toxicity of inhaled vapors from gasoline blended with any concentration of ethanol
Description:
The Energy Independence and Security Act of 2007 mandates increased use of alternative fuels in the American automobile fleet. Currently, the primary alternative to petroleum fuels is ethanol, and the public health risk associated with adding ethanol to gasoline at concentrations above 10% is uncertain. Potential neurological and immunological effects from developmental exposure to evaporative emissions from ethanol-gasoline blends are particular concerns. We have therefore begun a research effort involving computational modeling and animal experimentation, with the goal of estimating quantitatively the toxicity of inhaled vapors from gasoline blended with any concentration of ethanol. Modeling approaches include PBPK models parameterized in pregnant rats for inhaled ethanol (SA Martin abstract) and complex mixtures (WR LeFew abstract). The experimental model system involves exposing pregnant female rats to vapors of ethanol and gasoline-ethanol blends from gestational day 9 through 20, and determining dose-response relationships in their offspring, using behavioral, neurophysiological, and immunological assessments. Initial studies demonstrated that pregnant female Long-Evans rats (N = 8/group) tolerated a high concentration of inhaled ethanol (20,000 ppm, 6 hr/day for 12 days) without apparent distress and delivered viable litters. No significant differences in maternal weight gain, litter size, or offspring brain weight were observed, nor was fear conditioning affected in the pups at post-natal day (PND) 60. However, compared to controls, exposed pups grew more slowly, and motor activity was increased in females at PND 13 and decreased in males at PND 21. These effects remain to be replicated in a larger study with additional exposure concentrations. Future studies will compare dose-effect relationships across a range of gasoline ethanol blend ratios. This abstract does not reflect EPA policy