Over the last two months, Aoly Vilchez, whose child attends Gregori High School in Stanislaus County, has received more than 20 notifications from state authorities about pesticides being used near her son’s school. Gregori High is one of four county schools at high risk for pesticide exposure due to its proximity to agricultural fields.
On Tuesday, community members gathered in Modesto as part of a statewide action organized by Californians for Pesticide Reform. The event was held in five California cities and aimed to draw attention to concerns over new state rules on the use of 1,3-dichloropropene (1,3-D) and data showing increased application near schools and childcare centers.
Valley Improvement Projects (VIP), a local nonprofit, hosted the press conference at Tenth Street Plaza alongside similar events in Watsonville, Fresno, and Oxnard. Speakers criticized recent regulations finalized by the Department of Pesticide Regulation (DPR), which allow levels of 1,3-D exposure up to 14 times higher than what the Office of Environmental Health Hazard Assessment (OEHHA) considers an acceptable lifetime cancer risk.
Although banned in over 40 countries, 1,3-D remains widely used in Stanislaus County before planting crops like sweet potatoes, almonds, and cherries. Community advocates are pushing for a phaseout of all fumigant pesticides statewide and want school buffer zones expanded to at least one mile with these areas converted into organic farms or green spaces.
“We oppose a system that treats children as acceptable collateral damage,” said Bianca Lopez, co-founder of VIP and member of the Environmental Justice Advisory Committee at DPR.
The Department of Pesticide Regulation responded to The Bee with a statement: “The California Department of Pesticide Regulation (DPR) is committed to protecting public health and the environment through science-based regulation of pesticide use, including 1,3-dichloropropene (1,3-D). We recognize the concerns raised by community members and advocacy groups and take them seriously.”
DPR also stated it is working with OEHHA on further measures that could include larger buffer zones around applications sites and continued evaluation of exposure risks. These proposed rules would add to restrictions implemented in January 2024 following OEHHA consultation. If adopted, they will take effect January 1, 2026.
Field studies are underway between DPR and OEHHA regarding worker exposure to 1,3-D; results will inform future policy decisions. DPR added that Proposition 65 guidance issued by OEHHA serves a different purpose than regulatory limits: “While Prop. 65 is a guide for when a warning is needed (and can prod businesses to reduce use beyond what a regulation requires), DPR regulations restrict use,” according to their statement.
According to DPR figures cited during the event, emissions from 1,3-D dropped by nearly one-third from 2023–2024 after new fumigation methods were required starting in early 2024.
During the current academic year (2024–25), data compiled by VIP shows that more than ten thousand pounds of restricted-use pesticides were applied within a quarter-mile radius of twenty-four Stanislaus County schools. Chatom Elementary School along with nearby preschool programs were closest to some of the largest quantities applied.
Aoly Vilchez said through an interpreter: “Simply knowing what pesticide will be applied, when, and roughly where does not replace the need for precise, accessible and consistent data on the real levels of exposure in the air our children breathe every day.”
In recent years there have been two documented incidents involving pesticide drift onto school campuses—one at Modesto Christian School and another at Great Valley Academy—which affected twenty-five people who reported symptoms related to exposure. Bianca Lopez pointed out shortcomings in staff training on reporting such incidents: “What connects both incidents is something deeply concerning: School staff did not know how to properly report a pesticide drift incident.” She added that underreporting allows state officials to overlook problems.
Residents can sign up for alerts through “Spray Days,” an online notification system launched earlier this year that provides advance warnings about scheduled applications using restricted materials near homes or schools via interactive maps or text/email notifications.
Health experts warn that children face heightened risks from chemical exposures because their bodies are still developing. Mechelle Perea from Stanislaus State University’s School of Nursing noted how kids spend time close to surfaces where residues settle or play outside where drifting chemicals may accumulate. Exposure—including during pregnancy—has been linked with serious conditions such as cancer or neurological disorders.
“If we would never allow a bottle of poison to sit open on a counter, why would we allow fields of poison to surround our schools,” said Perea.
John Mataka from Grayson described disproportionate impacts on Latino and Indigenous farmworker communities as environmental racism. He referenced local efforts like the Stanislaus County Emissions Reduction Plan—a collaboration between VIP and Central California Asthma Collaborative—that aims both at reducing pollution sources ranging from agriculture chemicals to diesel emissions while promoting environmental justice initiatives like asthma education programs or incentives for organic farming practices.
Mataka urged local governments not just to wait for new state mandates but act now: “Waiting for Sacramento to do something is accepting continued harm,” he said.
