Mixtures of insecticides : pyrethroids, organophosphorus compounds, and carbamates : DRAFT

The purpose of this profile is to investigate the possible joint actions of pyrethroid insecticides, organophosphorus insecticides and carbamate insecticides on neurological end points in humans. In assessing the available information on possible interactions among these chemicals, this profile concludes with recommendations for conducting screening level assessments of public health concerns from joint exposure to mixtures of these chemical classes.The purpose of an Interaction Profile is to evaluate data on the toxicology of the \u201cwhole\u201d priority mixture (if available) and on the joint toxic action of the chemicals in the mixture in order to recommend approaches for the exposure-based assessment of the potential hazard to public health. Joint toxic action includes additivity and interactions. A weight-of-evidence approach is commonly used in these documents to evaluate the influence of interactions in the overall toxicity of the mixture. The weight-of- evidence evaluations are qualitative in nature, although ATSDR recognizes that observations of toxicological interactions depend greatly on exposure doses and that some interactions appear to have thresholds. Thus, the interactions are evaluated in a qualitative manner to provide a sense of what influence the interactions may have when they do occur.201