Newly posted state air monitoring data reveal that the average annual level of the fumigant pesticide 1,3-dichloropropene (1,3-D) near the Fresno County town of Parlier reached 0.35 parts per billion (ppb) in 2025 — 31% above the 0.27 ppb “action level” set by the California Department of Pesticide Regulation (DPR) as the trigger for further review and mitigation. DPR posted the results on its website with no public notice, and has yet to disclose the exceedance to the community or announce the follow-up review, as required by its own regulations.
“Once again, DPR is sitting on bad news instead of telling the people breathing this air,” said Angel Garcia, co-director of the statewide coalition Californians for Pesticide Reform. “The Department loves a press release when a number goes down. When a number blows past their own safety trigger, they bury it in a spreadsheet and hope nobody notices. That’s not regulation — that’s public relations for the pesticide industry.”
DPR’s Air Monitoring Network tracks 1,3-D at six sites across the state. Four of the six monitored communities saw annual average levels rise in 2025 over the prior year:
- Parlier (Fresno County): 0.16 ppb → 0.35 ppb (59% → 131% of the action level)
- Delhi (Merced County): 0.11 ppb → 0.16 ppb (40% → 58% of the action level)
- Santa Maria (Santa Barbara County): 0.04 ppb → 0.07 ppb (15% → 25% of the action level)
- Watsonville (Santa Cruz County): 0.03 ppb → 0.07 ppb (10% → 28% of the action level)
1,3-D is classified by the state of California as a human carcinogen and Toxic Air Contaminant. DPR established the 0.27ppb annual action level specifically as an early-warning threshold — a level meant to trigger review and consideration of mitigation. Parlier residents, especially those near the monitoring site, were breathing air that exceeds that line, in a community already overburdened by agricultural chemical exposure.
Concerns are compounded by the fact that DPR’s trigger for review of 0.27 ppb is almost 7 times higher than the 1,3-D Cancer No Significant Risk Level (NSRL) set by OEHHA, which is equivalent to 0.04 ppb. Annual and longer-term air levels at some of these monitoring sites exceed the NSRL many times over.
Under its own regulatory framework, DPR is required to follow up when the action level is exceeded. As of this release, DPR has not issued any public statement or press release about the Parlier exceedance, nor disclosed what, if any, follow-up review or mitigation steps are underway. DPR has also failed to notify residents, schools, or local health officials in the affected community.
“DPR needs to take a hard look at why air levels rose at more than half of their air monitoring sites after new regulations were put in place,” said Anne Katten with California Rural Legal Assistance Foundation.
The Californians for Pesticide Reform coalition is calling on DPR to:
- Disclose what mitigation measures, if any, are being considered or implemented
- Immediately and publicly notify Parlier residents, the local school district, and county health officials of the exceedance
- Commit to real-time, proactive public notification whenever any Air Monitoring Network site exceeds a DPR action level — not passive posting of raw data
- Explain why four of six monitoring sites saw 1,3-D levels rise in 2025, and evaluate whether the current regulations and action level are adequate to protect public health.