Date of Award

9-1993

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Systems Engineering and Management

Abstract

This study refines risk analysis procedures for trichloroethylene (TCE) using a physiologically based pharmacokinetic (PBPK) model in conjunction with the Monte Carlo method. The Monte Carlo method is used to generate random sets of model parameters, based on the mean, variance, and distribution types. The procedure generates a range of exposure values for human excess lifetime cancer risk of lxl0 (exp-6), based on the upper and lower bounds and the mean of a 95% confidence interval. Risk ranges were produced for both ingestion and inhalation exposures. Results are presented in a graphical format to reduce reliance on qualitative discussions of uncertainty. A sensitivity analysis of the model was also performed. This method produced acceptable TCE exposures, for total amount TCE metabolized, greater than the Environmental Protection Agency's (EPA) by a factor of 23 for inhalation and a factor of 1.6 for ingestion. Sensitive parameters identified were the elimination rate constant, alveolar ventilation rate, and cardiac output. This procedure quantifies the uncertainty related to natural variations in parameter values. Its incorporation into risk assessment could be used to promulgate, and better present, more realistic standards.

AFIT Designator

AFIT-GEE-ENV-93S-3

DTIC Accession Number

ADA270464

Comments

The authors' Vita pages are omitted.

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