Drift happens. Highly hazardous agricultural pesticides–linked to cancer, birth defects and nervous system damage–drift in harmful concentrations far from their intended targets, even onto school grounds where vulnerable children breathe and ingest them.
How do we know? While there’s an enormous amount of evidence all over the globe, we don’t need to look much further than the state air-monitoring reports of pesticides in Salinas and Watsonville and ongoing studies of Salinas Valley mothers and children.
The California Department of Pesticide Regulation reports that the toxic air contaminant and carcinogen 1,3-dichloropropene exceeded state cancer risk regulatory levels in the Salinas air in 2011 and in Watsonville in 2012. The Watsonville air monitor is on the grounds of Ohlone Elementary School.
Another toxic fumigant and lung damaging agent, chloropicrin, has been measured above or near regulatory levels of concern at the Salinas airport in the past two years. The CHAMACOS study by UC Berkeley scientists found brain-harming chlorpyrifos dust in large proportions of Salinas Valley homes near fields applied with the pesticide.
This is no surprise to our state and county regulatory bodies. It is illegal to expose people to drifting pesticides, yet our government agencies admit that drift is inevitable. The California Department of Pesticide Regulation (DPR) says: “[D]rift into surrounding air is expected with all pesticide applications.” But rather than prevent the crime of exposing us to toxic pesticides, the DPR and our county agricultural commissioners have chosen to “manage” the damage.
Sometimes the damage is in the form of dangerous, immediate, acute poisonings that make the news, like the 2009 drift incident at a local elementary school, described by the DPR:
In Monterey County, 940 feet north of an elementary school, a helicopter was spraying a spinach field with two fungicides, fenamidone and fosetyl-aluminum, when a physical education class came out into the school yard. When they saw the helicopter, the teacher brought the students back into the building and had them wash. Eleven of the thirty-two students and the teacher developed symptoms, which included eye irritation, nausea, headache, vomiting, and skin irritation. 
But the pesticide drift damage that is not so much in the headlines, the long-term illnesses that develop and manifest over time, may be an even greater pesticide danger. Damage to the brain, reproductive and respiratory systems, and cancer, among other documented pesticide-linked health threats, can take years or decades to be observable in individuals. At a Salinas news conference last year, teenage Alisal High student, Miguel Valdivia, expressed this concern when he observed, “If pesticides do have an effect on people, we’ll get to know. But sadly, we’ll know once it’s too late; once people are already affected by them.”
It is also no surprise to our state and county regulatory bodies that pesticide damage is focused in Latino populations. The state published data showing Latino children in Monterey County were 3.2 times more likely than white children to attend schools within a quarter mile of the heaviest use of the most highly hazardous pesticides. The University of California’s CHAMACOS studies have found significantly higher amounts of harmful organophosphate pesticides in urine samples of Salinas Valley Latinas than in the general U.S. population. As the executive director of the Center for Farmworker Families, Dr. Anne Lopez, has pointed out, the lack of protection from hazardous pesticide exposure for largely Latino populations is a form of environmental racism.
While a good deal of the rest of the world is moving away from—even banning—drift-prone fumigants, we have been much slower to take that responsibility in the United States and California. One step in the right direction, however, is the DPR’s current exploration of a statewide policy toward regulating the use of agricultural pesticides near schools. The state has not agreed to prevent drift from happening, but appears willing to address significant ways to reduce the likelihood children will be exposed to pesticides at school.
Among the most promising possibilities is the implementation of a significant protective zone where pesticides are not sprayed—a larger “buffer zone”—around all schools. Because many pesticides, especially fumigants, blow in the wind and volatize and drift long after applications, the buffer zones need to be large to be protective.
Scientific research going back at least 20 years has found that the closer homes are to pesticide treated fields, the increasing likelihood of exposure to pesticides, as measured by house dust and levels of metabolites in children’s urine. Greater distances from these fields, like buffer zones, reduces the risk of threats from drift and pesticide exposure.
Current buffer zones around schools don’t work. When cancer-risk levels of pesticides are measured in school grounds’ air, as the state found in 2012 at Ohlone Elementary, obviously the current buffer zones don’t work. The biggest reason is they are way too small. While Monterey County claims a “practice” of a 500-foot buffer around schools during schools hours, and Santa Cruz County has a 200-foot protective zone, a number of other counties have implemented buffer zones of a quarter mile for applications of restricted pesticides. Imperial County permit conditions go further and specify buffer zones of one mile for aerial applications and soil injection applications, and a half mile for ground applications of restricted pesticides.
San Luis Obispo County requires half-mile protection zones for aerial applications of restricted pesticides. The San Bernardino County ordinance requires up to a quarter-mile protection zone around schools for most applications of pesticide products labeled “Danger-Poison.”
While far larger than the buffer zones in the Monterey Bay area, these more expansive protective areas are still too short. The UC Davis MIND Institute study, the UC Berkeley CHAMACOS study, and the California Childhood Leukemia Study, all conducted in California, have shown that even quarter-mile buffer zones are insufficient to protect California’s children from unsafe pesticide exposures. The UC Davis MIND Institute study documented significantly increased rates of autism in children of mothers who lived up to one mile from fields. The CHAMACOS study has documented chlorpyrifos contamination in homes up to 1.8 miles from treated fields and the California Childhood Leukemia study found elevated concentrations of several pesticides in dust of homes up to three quarters of a mile from treated fields.
Given these experiences and scientific studies of the dangers of pesticide drift exposure within one mile of applications, we are calling for our pesticide regulators to push the use of drift-prone pesticides to at least one mile away from school grounds.
The Department of Pesticide Regulation visited Salinas last June for a workshop to hear from the public about what we want in terms of pesticide use policy near schools. The Cesar Chavez Library was packed, and the people were loud and clear: “One Mile Buffer! Our Children Shouldn’t Suffer!” Some of the speakers envisioned pesticide-free farming “innovation zones” around schools.
If the state DPR won’t act—and they’ve thus far scheduled a justice-delayed timeline of spring 2017 for implementation of a new pesticides and schools policy—then our county ag commissioners can. They have the authority to institute significant protective buffer zones any time they want. Let’s make sure they do.
Drift happens. Drift is a crime. Drift must end, and until then, schoolchildren at the very least should be protected from its dangers.
Want to join the fight against drift-prone pesticides and for sustainable farming? Safe Strawberry Monterey Bay Working Group meets every second Thursday at 6:30 p.m. at the Monterey Bay Central Labor Council in Salinas, 931 E. Market St., and every fourth Thursday at 5:30 p.m. at the Pajaro Valley Federation of Teachers in Watsonville. 734 E. Lake Ave.
Weller is organizer of Californians for Pesticide Reform for the Monterey Bay Central Labor Council. He can be reached at (831) 325-1681 or firstname.lastname@example.org
 Fenske RA, Lu C, Barr D, Needham L. Children’s exposure to chlorpyrifos and parathion in an agricultural community in central Washington state. Environ Health Perspect. 2002;110:549–553.
Simcox NJ, Fenske RA, Wolz SA, Lee IC, Kalman DA. Pesticides in household dust and soil: exposure pathways for children of agricultural families. Environ Health Perspect. 1995;103:1126–1134.
 The buffer zones in the San Bernardino ordinance apply only to properties adjacent to schools.
 Shelton, Janie F., et al. “Neurodevelopmental Disorders and Prenatal Residential Proximity to Agricultural Pesticides: The CHARGE Study.” Environmental Health Perspectives, June 23, 2014. doi:10.1289/ehp.1307044.
 Harnly, ME, et. al. “Pesticides in dust from homes in an agricultural area” Environmental Science and Technology, 43:8767-8774. 2009.
 Gunier, RB, et. al. “Determinants of agricultural pesticide concentrations in carpet dust.” Environmental Health Perspectives, 119:970-976, 2011.