The effect of temperature, salinity, and sterility on the degradation of malathion, parathion, methyl parathion, diazinon, and methoxychlor in fresh and estuarine water has been determined under controlled laboratory conditions. Surface water samples of 1, 10, 20, and 28 ppt salinity were amended with the above insecticides and incubated in the dark at 30, 20, and 10C under sterile and nonsterile conditions. Insecticide abatement was followed by electron-capture gas-liquid chromatographic techniques. No significant differences between sterile and nonsterile treatments were observed for any of the insecticides studies, while the effect of increasing temperature was highly significant with regard to increased degradation of malathion, parathion, methyl parathion, and diazinon. Salinity effects were varied among the four organophosphates.

"This report was submitted in fulfillment of grant no. R803842 by the Gulf Coast Research Laboratory, Ocean Springs, MS, under the sponsorship of the Environmental Protection Agency"--Page iv. Includes bibliographical references (pages 18-19). Microfiche