DPR Releases 2024 Air Monitoring Data
SACRAMENTO – The California Department of Pesticide Regulation (DPR) today released its 2024 Air Monitoring Network (AMN) Report, which analyzed over 200 samples collected in four California communities, comparing pesticide detections to health protective thresholds. Last year, no pesticides detected at DPR air monitoring stations exceeded those thresholds.
Long-term monitoring is critical for DPR to ensure the department’s analysis of current pesticide use laws and regulations are protecting people and the environment. The AMN is part of DPR’s continuous evaluation of pesticide uses to inform broader actions to regulate pesticides. The network includes four monitoring stations located in Oxnard, Shafter, Santa Maria and Watsonville — agricultural communities with high pesticide use. The stations collect weekly air samples, each of which is tested for 40 pesticides and breakdown products that have higher toxicity, use, or likelihood of becoming airborne. DPR also collects an additional 104 samples at two locations – Parlier and Delhi – to specifically test for 1,3-dichloropropene (1,3-D).
In 2024, 13 pesticides were detected at quantifiable levels, including 1,3-D, chloropicrin, methyl bromide (MeBr), and methyl isothiocyanate (MITC). All were detected below health protection thresholds, which means health effects are unlikely to occur.
“Monitoring air in agricultural communities helps us better understand potential pesticide exposure and evaluate the effectiveness of our protections,” said DPR Director Karen Morrison. “It is critical we are in the areas where the most pesticides are being used so we have the data to understand where there are potential exposure concerns. This work is a key part of how we use science and data to protect public health and the environment, and we welcome continued input from all parties interested and impacted by pesticide use to inform our actions to address risks.”
Several fumigants detected in 2024 — 1,3-D, chloropicrin, methyl bromide, and MITC —are subject to strict requirements in California that prohibit their use except with a specific license and annual permit reviewed by the local county agricultural commissioner. DPR also has several evaluations underway as part of its broader mission to foster sustainable pest management. The department is currently conducting a reevaluation of chloropicrin, and an independent study focused on alternatives to pre-plant fumigants such as MITC and methyl bromide is anticipated for release in 2026. DPR is also developing additional regulatory actions to restrict the use of 1,3-D.
DPR will host a series of virtual public meetings in December to provide information on the 2024 AMN Report for the communities where monitors are located.
More information on the meetings is available on DPR’s website.