Potentiation of Toxicity in Mixtures

Organic Pollutants An Ecotoxicological Perspective, Second Edition 

Most statutory toxicity testing is done on individual compounds. In the natural environment, however, organisms are exposed to complex mixtures of pollutants. Toxicity testing procedures are described for environmental samples that contain mixtures of different chemicals. 

Particular attention is given to the development of new mechanistic biomarker assays and bioassays that can be used as indices of the toxicity of mixtures. These biomarker assays are typically based on toxic mechanisms such as brain acetylcholinesterase inhibition, vitamin K antagonism, thyroxin antagonism, Ah-receptor-mediated toxicity, and interaction with the estrogenic receptor. They can give integrative measures of the toxicity of mixtures of compounds where the components of the mixture share the same mode of action. They can also give evidence of potentiation as well as additive toxicity. 

Bioassays can be used for cost-effective biomonitoring and rapid screening of environmental samples to detect the presence of mixtures of toxic chemicals and to identify hot spots. 

and Leonzio, C. (1994). Nondestructive Biomarkers—A collection of detailed reviews of nondestmctive biomarkers. 

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