Use of Predictive Toxicology Methods to Estimate Relative Risk of Complex Chemical Waste Mixtures

Abstract

ABSTRACT

This paper provides an overview of methodologies and toxicological procedures which may be used to evaluate the relative health risk posed by exposure to hazardous waste mixtures. The pragmatic approach to risk assessment at hazardous waste sites includes a three-phased study. Phase one is the determination of the nature and quantity of the toxic chemicals present. This involves monitoring for potential toxic chemicals in the air, all bodies of water, particularly drinking water, and soil. The next step is to evaluate environmental media pathways to determine the greatest potential for human exposure. The demographic characteristics and sensitivity of the human populations at risk and their proximity to the toxic waste must be defined. Finally, an estimation of anticipated toxicological effects associated with these various exposures must be examined. The establishment of dose-response relationships is a priori to predicting correlations between identified toxic chemicals and an adverse human health effect.

The emphasis of this paper is on predictive toxicology tests and parameters which can be used to establish dose-response relationships at hazardous waste sites. Extrapolating laboratory animal toxicity data to man and deriving meaningful appraisals of human health risks remains a perplexing problem in toxicology. A more complete understanding of structure-activity relationships, pharmacokinetic factors and mechanisms of toxicity must be achieved to adequately address this issue within the context of hazardous waste risk assessment.