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Biofuels Research at EPA
Citation:
BOYES, W. K. Biofuels Research at EPA. Presented at Toxicology and Risk Assessment conference, Cincinnati, OH, April 27 - 28, 2010.
Impact/Purpose:
In our lab we are interested in the potential health hazards of exposure to evaporative and combustion emissions resulting from biofuel use.
Description:
The development of sustainable and clean biofuels is a national priority. To do so requires a life-cycle approach that includes consideration of feedstock production and logistics, and biofuel production, distribution, and end use. The US Environmental Protection Agency is supporting research into the health and environmental impacts of all these life cycle stages for current and potential future biofuels. In our lab we are interested in the potential health hazards of exposure to evaporative and combustion emissions resulting from biofuel use. Currently, the primary biofuel in use for the US automotive fleet is a mixture of 10% ethanol with gasoline (ElO), with E85 available for some flexible fuel vehicles. There is potential for future increased use of these fuels and also introduction of other blended mixtures such as E 15. The switch from gasoline to ethanol/gasoline blends is associated with changing emission and exposure profiles for both evaporative and combustion emissions. Among these changes are increased evaporative emissions of ethanol and increased combustion emissions of acetaldehyde. The most sensitive health outcome for oral ethanol exposure is thought to be the developing nervous system, and acetaldehyde is a primary metabolite of ethanol that may be responsible for some of the toxicity of ethanol. There is little information regarding inhalation exposure to ethanol in a developmental context. We are undertaking a project to evaluate the potential hazards to the developing nervous system of exposure to ethanol vapor alone and in a mixture with other gasoline evaporative emissions, using a rat model. Physiologically-based pharmacokinetic (PBPK) models of ethanol alone and ethanol-gasoline mixed vapors will be created to predict tissue concentrations following exposures to the developing animal. Both oral and inhalation routes of exposure will be included, so that the extensive literature available for oral ethanol exposure can be used to quantify effects on the basis of target tissue dose (concentration in the brain). Experimental animal studies will involve inhalation exposures to pregnant rats of ethanol and ethanol/gasoline vapor blends. Dosimetric studies will assess concentrations of ethanol and gasoline index chemicals to evaluate the performance of the PBPK models. Toxicity studies will assess a variety of neurobehavioral, neurophysiological and physical parameters throughout the growth and development of the offspring. A range ofethanol blend ratios will be tested to build models capable of estimating the hazards of any new blend ratio that may come into the market. This abstract does not reflect EPA policy.