Diazinon in municipal effluents and ambient waters for the upper Trinity River, Texas




Crocker, Philip A., Jack R. Davis, Terry A. Hollister, and Evan Hornig

Journal Title

Journal ISSN

Volume Title


U.S. Environmental Protection Agency, Water Management Division, Water Quality Management Branch, Technical Section and the Texas Water Commission, Water Quality Standards and Assessment Section


Diazinon is a broad spectrum organophosphate insecticide used widely both around the home and in agriculture for the control of soil insects, such as wireworms, cutworms, fire ants, etc. In spite of its broad usage in Texas and other Region 6 states, there has been little in the way of environmental monitoring for diazinon to assess its potential effects on aquatic life. Diazinon is highly toxic to numerous benthic macroinvertebrate and zooplankton species, particularly midges, amphipods and daphnids, with an acute LC50 value for Ceriodaphnia dubia of 0.36 ug/l. Low levels are also chronically toxic to fish species following long-term exposure.


36 pgs.


diazinon, toxicants, water quality, municipal effluents, ambient water, upper trinity river