The Toxicology of Chemical Mixtures Risk Assessment for Human and Ecological Receptors

Mixtures of chemicals represent a concern in all areas of toxicology and a challenge to risk assessors as most sites with environmental contamination, including Department of Defense sites, involve simultaneous or sequential exposures of multiple chemicals to human or ecological receptors. A major concern with mixtures is that they may lead to outcomes health effects or increased toxicity synergism not expected from the risk characterization of individual chemicals at the site. The focus of this literature review is 0 examine the principles used to determine toxicity in chemical mixtures risk assessment for human and ecological receptors at hazardous waste sites. This review provides an overview of current practices useful to a remedial project manager or risk assessor prior to their first chemical mixtures risk assessment.