Atrazine and organophosphate insecticides

43 Atrazine and organophosphate insecticides Sometimes more surprising examples of interaction may be observed. 

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Pape-Lindstrom, P.A. and Lydy, M.J. (1997) Synergistic toxicity of atrazine and organophosphate insecticides contravenes the response addition mixture model, Environmental Toxicology and Chemistry 16 (11), 2415-2420. 

Belden, J. and Lydy, M. 2000. Impact of atrazine on organophosphate insecticide toxicity. Environ. Toxicol. Chem., 19, 2266-2274. 

Crop protection chemicals are an important group of contaminants that exhibit biologically mediated transformation in aerobic or anaerobic subsurface environments. We consider two well-known contaminants the insecticide parathion, which is an organophosphate compound, and the herbicide atrazine, from the triazine group. 

Systematic investigation of pesticides in the Chesapeake Bay watershed began in the 1970 s in response to the observed decline in SAV and fish populations during that period. Investigations typically spanned a few years and tested for specific families of herbicides (e.g., dUoro-s-triazines and chloroacetanilides) and insecticides (e.g., organophosphates and chlorinated hydrocarbons) in various media. Detection limits and consistency in the methods of data collection improved with time. The data that are sununarized below consist of measurements of concentrations of atrazine in the iiqruts to surface waters at several locations throughout the Bay. We should stress that data are sparse spatial and temporal distributions have to be estimated and/or extrapolated from measurements in the top 0.5-1.0 m of the surface layer. 

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