DPR Releases 2025 Air Monitoring Reports

The California Department of Pesticide Regulation (DPR) has released two reports summarizing annual findings from its program to monitor pesticides in the air.

The 2025 Air Monitoring Network (AMN) Report summarizes DPR’s air monitoring activities and findings for 2025. This includes data collected across four monitoring sites for 40 pesticides and breakdown products. The Study 309 Report is DPR’s long-term 1,3-dicholopropene (1,3-D) air monitoring study and includes 1,3-D data from two air monitoring stations in Fresno and Merced Counties for 2025.

Both reports were updated to reflect the California Department of Food and Agriculture (CDFA) Center for Analytical Chemistry’s recall and voiding of some air monitoring data due to significant degradation of a laboratory reference standard. CDFA provides the independent lab analysis for DPR’s air monitoring program and recalled about nine months of 1,3-D and methyl bromide (MeBr) data. As a result, the 2025 AMN Report includes full‑year results for 38 pesticides and degradants and nine months of 1,3-D and methyl bromide data that were not affected by the recall. The Study 309 Report includes nine months of valid 1,3-D data from the two air monitoring stations in Parlier and Delhi.

In total, nine compounds were detected at quantifiable concentrations in 2025. All detected concentrations were below health based screening levels and regulatory targets.