DPR operates four monitoring stations in areas with high pesticide use
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SACRAMENTO — The California Department of Pesticide Regulation released its annual Air Monitoring Report, which found that no air samples taken at monitoring sites in 2023 detected pesticides at or above health-protective screening levels or regulatory targets.
DPR operates four monitoring stations in areas with high pesticide use: Oxnard, Santa Maria, Shafter and Watsonville. The stations collect weekly air samples, which are tested for 40 pesticides.
The 2023 data found that 95% of all samples collected had no detectable pesticides. Twenty-one pesticides were not detected at all, and 11 were detected at very low, trace levels which indicates unlikely risk to or impact on people’s health.
Seven pesticides were detected at quantifiable levels, with detections falling below health-protective screening levels or regulatory targets. Those pesticides were 1,3-dichloropropene, captan, dichlorvos (DDVP), methyl isothiocyanate (MITC), malathion, methyl bromide and pendimethalin.
DPR is evaluating concentrations of one pesticide, chloropicrin, which peaked at just below the health screening level (7% below) to inform any necessary future action.
Screening levels are developed by DPR scientists through scientific evaluation to conservatively estimate when a pesticide air concentration may have any impact on human health. DPR measures air against screening levels and regulatory targets. Regulatory targets are screening levels associated with a regulatory requirement to mitigate pesticide risks or impacts. A pesticide detection below a specific screening level or regulatory target indicates that adverse health effects are unlikely, including short-term (acute) pesticide impacts, such as eye or throat irritation, nausea, headaches or blurred vision, or long-term (chronic) pesticide risks such as birth defects or nervous system problems. DPR also measures for exposures that could increase the lifetime risk for cancer.
Pesticide concentrations measuring near and above a screening level are evaluated by DPR to examine what conditions may have caused the elevated reading or to inform any future mitigation that may be needed to protect the health of people in high pesticide use areas and throughout California. Specifically for chloropicrin, DPR is conducting a detailed evaluation of pesticide use data and historical weather patterns, in addition to modeling and additional monitoring to better understand potential sources and exposures in the area. DPR plans to release its analysis specific to the chloropicrin detection in 2025.
Air monitoring is an important element of DPR’s continuous evaluation process, which includes tracking, monitoring and evaluating the risk and impact of legal pesticide use in California to inform any actions or mitigation measures needed to continue to protect people and the environment.
“Monitoring the air in communities with high pesticide use is critical to keeping California safe for everyone,” said DPR Director Julie Henderson. “I am encouraged to see that all of the 2023 pesticide concentrations fall below our health screening levels. We are still evaluating the concentrations of chloropicrin and are committed to continue collecting and reviewing our data rigorously to identify areas of potential concern, trend lines or anomalies that indicate a need for closer investigation or action.”
The fumigants detected by DPR’s air monitoring stations – 1,3-dichloropropene, chloropicrin, methyl bromide, and MITC – are all restricted material pesticides, requiring applicator training and licensing, mandatory setbacks from buildings, the use of tarps to cover treated areas or other application methods with comparable levels of emission reduction, and other restrictions on use. New regulations restricting the use of 1,3-dichloropropene went into effect January 2024, and include requirements for larger setbacks from buildings, new tarp and soil application requirements, and additional restrictions to protect residential bystanders (people living near agricultural fields) from potential exposure. DPR is developing new regulations to further restrict the use of 1,3-dichloropropene to add specific protections for occupational bystanders (people that may work near an area where the pesticide was applied).
DPR will be presenting the results from the 2023 air monitoring study at the department’s Pesticide Registration and Evaluation Committee meeting, scheduled for 10 a.m. Oct. 25, at the California Environmental Protection Agency building in Sacramento (1001 I St.). The meeting is also available online via Zoom or view-only through the CalEPA webcast. DPR is also accepting public comments on the report through 5 p.m. Nov. 12; comments can be submitted online via the department’s public comment portal.
December 12 Virtual Community Meeting on 2023 AMN Report:
DPR is hosting a virtual meeting to provide information on the 2023 air monitoring results for communities where monitors are located (Oxnard, Santa Maria, Shafter and Watsonville). The meeting will be available in Spanish and English. To request interpretation in additional languages, please email languageaccess@cdpr.ca.gov by Friday November 29, 2024.
- Date: December 12, 2024
- Time: 6 p.m.-7:30 p.m.
- Location: Zoom (virtual). You can login using this link prior to the start of the meeting. You will be prompted to enter an email address to join. This is a Zoom requirement.
Visit DPR’s website to view the full 2023 Air Monitoring Report.
For more on DPR’s air monitoring program, including past air monitoring reports, see our website.
–California Department of Pesticide Regulation
(Photo: Josh Hild, Unsplash)