You are here:
APPLICATIONS OF DOSIMETRY MODELING TO ASSESSING NEUROTOXIC RISK.
Citation:
Boyes, W K., J E. Simmons, C Eklund, V A. Benignus, P. Janssen, AND P J. Bushnell. APPLICATIONS OF DOSIMETRY MODELING TO ASSESSING NEUROTOXIC RISK.
Description:
Risk assessment procedures can be improved through better understanding and use of tissue dose information and linking tissue dose level to adverse outcomes. For volatile organic compounds, such as toluene and trichloroethylene (TCE), blood and brain concentrations can be estimated using physiologically based pharmacokinetic models. Acute changes in the function of the nervous system can be linked to the peak concentration of test compounds in the brain, and not to other possible measures of tissue dose such as area under the curve. This set of information enables application to a number of risk assessment situations. For example, we have used this approach to recommend duration adjustments for acute exposure guideline levels (AEGL) for TCE such that the exposure limits at each exposure duration yield identical peak tissue concentrations. We have also used peak dose information to compare sensitivity across species, adjusting for species-specific pharmacokinetic differences. Finally this approach has enabled us to compare the relative sensitivity of different compounds on a tissue dose basis, leading in one case to expressing acute solvent exposure as ethanol-dose equivalents for purposes of estimating cost benefit relationships of various environmental control options. This is an abstract of a proposed presentation and does not reflect EPA policy.