Quick Take
For more than 30 years, science has warned that organophosphate pesticides damage developing brains, especially in pregnant women and children, writes local activist and retired nurse Kathleen Kilpatrick. Yet the Monterey Bay region remains a hotspot for exposure, with some of the highest rates in California. The consequences show up not only in labs, but also in Pajaro Valley schools where Kilpatrick worked, in special education rolls and long-term social costs. It’s time to stop managing the damage and phase out these toxic, outdated chemicals for good, she writes.
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Thirty years ago, I was a grad student at the University of Washington, studying to be a nurse practitioner and taking additional courses in occupational and environmental health. I got a summer job as a nurse collecting exposure samples from kids whose parents applied pesticides in the Wenatchee Valley.
We were looking to see if the fathers’ exposures were being passed on to their kids. One evening, we were standing in front of a trailer talking with a pesticide applicator and his family when a small plane flew over a nearby orchard, dousing us all with spray.
“Malathion,” the dad said.
What he didn’t say, and might not have known, is that malathion, an organophosphate pesticide (OP), is a potent neurotoxin.
Little was known then about the impacts of perinatal exposure to organophosphates, so we weren’t asking the moms anything about their pregnancies. We didn’t know that exposure to even small amounts at key developmental periods or by sensitive individuals could cause lifelong consequences.
PESTICIDES IN THE PAJARO VALLEY: Read more Lookout news and Community Voices opinion coverage here
The dangers of acute poisoning from these pesticides have been known for decades now. In the years of Hitler’s Nazi regime, they were developed as chemical warfare agents and insecticides. Their use in agriculture exploded in the 1960s and 1970s to replace DDT and other organochlorines, which were being banned and restricted after the publication of Rachel Carson’s “Silent Spring.”
OPs break down more quickly than DDT and its ilk. But it turns out that exposure to even tiny amounts may have lingering effects, especially on vulnerable groups like pregnant women and young children.
Sadly, our Monterey Bay region remains a likely hotspot for exposure, particularly for pregnant women.
This year, a group of researchers published a report based on state pesticide use data from 2016 to to 2021. They wanted to look at whether OP use had declined after California banned a particularly potent OP, known as chlorpyrifos, after Dec. 31, 2020.
In most of the state it had, but much less so in the Salinas Valley and the surrounding area. The researchers used a metric from the CHAMACOS study on perinatal exposure that correlated risk of harm with living one kilometer (0.6 miles) from a field where OPs were applied during a mother’s pregnancy.
Statewide, that was 7.5% of women. In Monterey County, it was over 50% of women.
In Santa Cruz County in 2021, 29% of pregnant women lived within a kilometer of OP-sprayed fields. In the Pajaro Valley, that percentage would be considerably higher, and many of those pregnant women also worked in the fields.
The project I worked on years ago was one of a series of three on organophosphate exposure of Wenatchee Valley kids. Researchers in that series discovered that even more OPs accumulated inside people’s homes than in the yards outside homes where kids played. The closer a family was to the orchards, the more OPs were in their homes. Having a parent working in agriculture raised home levels.
But they also found OPs in carpets in the control houses farther away, and in homes with parents who didn’t work in agriculture.
Pesticides in outdoor soil decreased after spraying. However, the accumulated levels from house dust in workers’ homes tended to increase over time.
“We probably induced more than one heart attack when we presented our results to the leaders of the tree fruit industry,” Richard Fenske said at the time.
The responses were disappointing. Basically, those leaders ignored or dismissed the studies, calling the levels “too low to cause any harm” and “not our problem.”
But industry leaders “did start thinking about children’s health, especially their own children, many of whom lived amidst the orchards,” Fenske said.
Air, dust, on skin, clothes, in food and water: these are OP pathways into our bodies. We’ve known these chemicals are toxic, that children are especially sensitive, and that they have been exposed in agricultural communities like the Pajaro Valley for more than 30 years.
Yet 14 OPs are still approved for use in California, and our Monterey Bay region is disproportionately affected by OP use.
Fenske was one of my professors 30 years ago at the University of Washington. He investigated pesticide poisons found in carpets where kids crawled. His focus was chlorpyrifos, a highly toxic OP used in agriculture but also available then to kill insects indoors, usually through aerosol canisters sold over the counter.
Kids were literally dying from flea bombs, yet it took until 2000 to get chlorpyrifos banned from indoor use.
Fast forward to 2018: a hearing in Sacramento by a state panel, the Office of Environmental Health Hazard Assessment (OEHHA), on agricultural use of chlorpyrifos in California. Multiple researchers found correlations between OP exposure and neuro-developmental problems such as learning disabilities, behavior changes, decreased IQ and autism. And multiple studies, done since their use was EPA-approved, associated perinatal exposure with these harms.
Locally, the CHAMACOS project, conducted in the Salinas Valley by the UC Berkeley School of Public Health, has followed children from before birth through young adulthood. Its team has published over 150 studies on pesticide impacts.
Chlorpyrifos, like other OP insecticides, kills insects and causes acute poisoning by scrambling signals in the nervous system. The OEHHA scientists reviewed studies that looked beyond acute symptoms and couldn’t find clear correspondence between markers of exposure in the blood and other kinds of effects.
They couldn’t pin down a safe level for pregnant women and infants, and there were also signs that some individuals might be more sensitive.
Without a quantifiable safe threshold, harmful pesticides can’t be well managed. And without a workable way to mitigate risks, they can’t be used. On these grounds, California removed registration for chlorpyrifos use on food products in 2020.
From zebrafish to humans, results of testing of OPs show harms to learning and alteration of behavior. It’s also become clear: knocking down these toxic pesticides one at a time will take too long. Too many people risk exposure and the consequences.
What are some potential costs of those harms?
I was a school nurse in the Pajaro Valley from 2000 to 2017, serving individual schools and students, as well as working on improving our health services overall. We dealt with all kinds of health issues that affected learning: vision and hearing, infections, asthma, life-threatening illnesses like cancer and kidney disease.
Kids I heard most about from teachers were those who struggled to learn, who couldn’t sit still or control their impulses, who made learning hard for the other students as well. The teachers wanted those kids to get help, which often meant referral for special education.
I live with a special ed teacher. I heard about those kids from him, too; his Pajaro Valley classes always had several. The same kinds of health, learning and behavioral issues that showed up in the labs where OPs were studied and in the human epidemiological studies like CHAMACOS were besetting our Pajaro Valley Unified School District students.
We’ll skip the details of what it takes to qualify for special education, how underresourced it is, and focus on potential long-term costs: If you had a specific learning disability in 2017, you had only a 46% chance of being in the workforce.
Another study from around the same time found that 20% of prisoners had been in special education. A few points of IQ loss might not have a big impact on one person, but can have a huge impact on a community or population; economic costs are huge, social costs might be even higher.
PVUSD, the district where my companion and I worked, has suffered falling enrollment in the years since we retired. The percentage of students in special ed, however, has increased, from around 11% to well over 15% – higher than the state average of 13% and the county average of 13.7%.
Our district schools have responded by increasing behavioral support services and counselors to support keeping struggling students in the classroom. Now, with budget shortfalls, most of those positions are on the chopping block.
Here’s another way of quantifying our children’s risk: There are 15 school districts between Aptos and San Ardo. From 2017 to 2022, close to the same time frame as this year’s study, over 1.5 million pounds of organophosphates were applied within their boundaries.
Over a third of a million pounds were applied in the three districts in and around the Pajaro Valley.
Are children affected by OPs once again being harmed by forces beyond their control?
Of course they are – and our kids and communities deserve better.
The current science showing harms from OP exposure to developing brains and bodies is compelling. The evidence from maps and tallies that show residents of the Pajaro and Salinas Valleys are disproportionately exposed is also compelling.
So what can we do?
We can increase buffers and notification; our ag commissioners have the power to do that, and our communities should demand they do. We can advocate for organically farmed buffers around schools.
But let’s also focus on phasing out all OPs, and let’s not take another 30 years to do it.
OP use has declined almost everywhere else in California, but in the Monterey Bay region, it’s stalled. Alternative methods are available and in use and should be adopted.
Monterey and Santa Cruz counties have a rich heritage of successful organic farming, small to large, old school to highly innovative.
OPs are harmful and obsolete. We can make our communities safer and grow better food without them.
Kathleen Kilpatrick has been a midwife, done pediatric and geriatric home care, worked in a farmworkers’ clinic, taught nursing, and worked in PVUSD from 2000 to 2017, after serving as team leader for district health services. She is committed to continue work on public health issues as key aspects of social and environmental justice.