Ambient air concentrations of pesticides in California

The California Air Resources Board conducted ambient air monitoring of pesticides in support of the California Department of Pesticide Regulation toxic air contaminant program. Monitoring was done in several communities in a county of high use during the month of expected peak use of a particular pesticide in order to assess general population exposure. Additional sampling was conducted adjacent to snecific agricultural applications to assess maximum short-term concentrations to which the public might be exposed. Medium and low volume samplers were used with appropriate collection media (e.g., Teflon filters, XAD-2 adsorbent resin), followed by laboratory analysis, Concentrations measured around specific applications would be expected to be representative of other areas, especially in California, with comparable application rates, crops, and weather conditions. Since the program began in 1986, monitoring has been conducted for 22 pesticides. Results for three soil fumigants were of potential public health concern and led to the suspension of permits for the use of one pesticide and were used in the development of use modifications and buffer zones for two others.