Assessing Joint Actions of Insecticides on Neurological Health: ATSDR Recommendations for Public Health Screening

The Agency for Toxic Substances and Disease Registry (ATSDR) has investigated potential joint effects of pyrethroid, organophosphorus, and carbamate insecticides on human neurological health. In examining the available information regarding interactions among these chemical classes, the published profile offers recommendations for conducting preliminary assessments of public health concerns arising from simultaneous exposure to mixtures of these chemicals.

ATSDR suggests that, for screening-level assessments of potential adverse health effects resulting from concurrent oral exposure to pyrethroids, organophosphorus, and carbamate insecticides, a default assumption of dose-additive joint action should be applied, especially concerning neurological endpoints. The assessments should include qualitative descriptions of weight-of-evidence evaluations for interaction data, indicating that greater-than-additive effects are possible between specific pyrethroids and organophosphorus insecticides. However, the data on interactions between pyrethroids and carbamates are inconclusive.

The evidence does not strongly support departing from a dose-additive approach for screening-level assessments, as the relevance of greater-than-additive interactions to environmental exposure levels remains uncertain.

MORE INFO ON: www.atsdr.cdc.gov