Analysis of chlorpyrifos agricultural use in regions of frequent surface water detections in California, USA.
Chlorpyrifos is a common surface water contaminant in California, USA. We evaluated five years of chlorpyrifos use and surface water monitoring data in California's principal agricultural regions. Imperial County and three central coastal regions accounted for only 10% of chlorpyrifos statewide use, but displayed consistently high aquatic benchmark exceedances (13.2%-57.1%). In contrast, 90% of use occurred in Central Valley regions where only 0.6%-6.5% of samples exceeded aquatic benchmarks. Differences among regions are attributable to crop type, use intensity, irrigation practices and monthly application patterns. Application method did not appear to be a factor.
Environmental Monitoring Branch, California Department of Pesticide Regulation, 1001 I Street, Sacramento, CA 95812, USA. xzhang@cdpr.ca.gov
Xuyang
X
Zhang
Keith
K
Starner
Frank
F
Spurlock
D000383:Agriculture / Q000379:methods*; D002140:California; D004390:Chlorpyrifos / Q000032:analysis*; D004784:Environmental Monitoring; D007306:Insecticides / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data
D007306:Insecticides; D014874:Water Pollutants, Chemical; D004390:Chlorpyrifos