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 Regul ation toxic air contaminant program. Monitoring was done in several co mmunities in a county of high use during the month of expected peak us e of a particular pesticide in order to assess general population expo sure. Additional sampling was conducted adjacent to snecific agricultu ral 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 adsorbe nt resin), followed by laboratory analysis, Concentrations measured ar ound specific applications would be expected to be representative of o ther areas, especially in California, with comparable application rate s, crops, and weather conditions. Since the program began in 1986, mon itoring has been conducted for 22 pesticides. Results for three soil f umigants were of potential public health concern and led to the suspen sion of permits for the use of one pesticide and were used in the deve lopment of use modifications and buffer zones for two others.