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Department of Pesticide Regulation Initiates Air Monitoring of Pesticides in Kern, Monterey and San Joaquin Counties

Media Contact: Lea Brooks
916-445-3974 |
March 1, 2011 (11-04)

SACRAMENTO – The Department of Pesticide Regulation (DPR) has launched an air monitoring network in three agricultural communities to expand its knowledge of the potential health risks of long-term exposure to pesticides, DPR Director Mary-Ann Warmerdam announced today. The network was set up last month in Shafter in Kern County, Salinas in Monterey County and Ripon in San Joaquin County.

“The air monitoring network is the first of its kind in the nation,” Warmerdam said. “Our intent is to make more accurate estimates of health risks based on long-term exposure rather than extrapolate from short-term monitoring data to determine if additional protective measures are needed.”

DPR will monitor for 34 pesticides, including six fumigants and 11 organophosphates. DPR selected these pesticides based on the amount of use and their potential health risks.

Shafter, Salinas and Ripon were selected from a list of 226 communities based on pesticide use on surrounding farmland and demographics, including percentage of children, the elderly and farm workers. Depending on resources, DPR may expand the air network in the future to include more frequent sampling, more pesticides or more communities.

“Communities surrounded by farmland should not be surprised when air monitoring detects pesticides, ” Warmerdam emphasized. “DPR has established levels for these pesticides in the air to protect human health and the environment. The network will provide valuable information to evaluate the effectiveness of protections that are in place, including label restrictions and requirements on fumigant applications.”

The network is a follow-up to DPR’s groundbreaking pilot projects in Parlier in Fresno County in 2006 and Lompoc in Santa Barbara County in 2000, which lasted 12 months and 10 weeks, respectively. These pilots helped DPR improve data collection and analysis methods, including: the ability to select communities for monitoring based on DPR risk assessment priorities and related criteria; detect multiple pesticides in a single sample; and use a geographic information system to compare pesticide use to detected concentrations.

DPR will monitor one site each in Shafter, Salinas and Ripon. One 24-hour sample will be collected from each site weekly. Data collected from Parlier demonstrated that monitoring a single location once a week provides adequate data to estimate long-term concentrations. Data collected by the network will be released annually beginning in 2012.

DPR will compare pesticide concentrations with screening levels developed by its scientists, track trends in air concentrations and correlate concentrations with use and weather patterns. In the absence of federal or state enforceable health-based limits on pesticide emissions in air, DPR set screening levels. Although not regulatory standards, the screening levels are guideposts for preliminary evaluations of air monitoring data.

State law requires DPR to continuously evaluate pesticides after they are in use. As part of this process, DPR conducts field studies to monitor exposure to workers and to measure how pesticides move and break down in air, soil and water. DPR uses this information to decide if further regulatory measures are necessary.

In 2009, pesticide use declined for the fourth consecutive year in California. Pesticide use varies from year to year depending on a number of factors, including weather, pest problems, economics and types of crops planted. However, growers are shifting from broad-based pesticides to new products more specific to the pest and less toxic to people and the environment.

More information on the air monitoring network, including the list of pesticides being monitored, is posted at:


One of five departments and boards within the California Environmental Protection Agency, DPR regulates the registration, sale and use of pesticides to protect people and the environment. For more information about DPR and previous IPM Innovators, see