Dangerous Drift

Photo: File/Thinkstock
Photo: File/Thinkstock

In the predawn hours of Oct. 3, 2012, two farm labor crews arrived at fields southeast of Salinas to harvest lettuce. A light breeze blew from the north across rows of head lettuce and romaine. As the sun rose higher in the sky, the workers started to smell an acrid odor that some described as paint, others as cilantro seeds or diesel fumes. The workers’ eyes began to burn and water; many complained of nausea, headache, dizziness and shortness of breath. No pesticides were being sprayed at the time, but still, the workers were displaying classic symptoms of pesticide illness.

The source of the odor was drift from a pre-plant strawberry field—a 25-acre barren plot of soil that had been fumigated the day before with a mixture of highly toxic and volatile chemicals 1,3-dichloropropene (also called 1,3-D and sold under the brand name Telone) and chloropicrin.

On the morning of Oct. 2, the fumigant had been injected into the soil through a drip irrigation system beneath high- barrier tarps. Eighteen hours later, 43 people—many of them working as far away as 2,000 feet south of the field—were sickened from poisonous gases that had escaped.

This case, like so many others listed in the state’s Pesticide Illness Surveillance Program, highlights a major problem with pesticides—they don’t necessarily go where they’re intended and, once applied, they don’t necessarily stay there.

When most people think of pesticide drift, they think of spray drift, which happens during application as droplets are carried by wind. But post-application drift happens hours, days or even weeks after a pesticide is applied.

Some pesticides that settle into soil will travel in the wind with dust. Other more volatile pesticides will vaporize into a gaseous state at relatively low temperatures, diffusing into the air much as vapors from a sliced onion will fill a room and irritate your eyes. Volatilized pesticides rapidly travel wherever the wind is blowing. In the 2012 incident near Salinas, the fumigant likely volatilized as the morning sun warmed the field, and the chemicals subsequently drifted downwind to where workers were harvesting lettuce.

When investigators from the Monterey County Agricultural Commissioner’s Office arrived shortly before noon on Oct. 3, they found no tears or holes in the tarps. Because they determined that no pesticide laws had been broken when the fumigant was applied, they issued no violations to pest control applicators.

Current state pesticide laws and regulations were written specifically to govern illegal drift that occurs from application violations—leaving a legal gray area around the more difficult- to-control drift that occurs after an application.

“How volatilization is dealt with in California is an ongoing issue and a very big problem,” says Pearl Kan, an attorney with the Salinas office of California Rural Legal Assistance. “It doesn’t protect farmworkers or community members from exposure.”

Pesticide drift is often insidious, present in concentrations too low to cause immediate noticeable symptoms. No one really knows how this silent drift affects us. Few studies have looked at long-term, cumulative health effects in humans exposed to low concentrations of pesticides—and even fewer have looked at synergistic effects of exposure to a cocktail of different chemicals.

Driving south down Highway 101 toward Salinas, you can see a shimmering sea of plastic stretching for miles across the fluvial valley. Plastic tarps cover much of this farmland to contain fumigants that are pumped into the soil to kill the nematodes, fungi and bacteria that threaten Monterey County’s $869.5-million strawberry industry. Together with the Pajaro Valley to the north, this Central Coast region encompasses nearly half the state’s acreage devoted to strawberry production. But in order to produce the 4.5 million trays per week that are projected for the peak season, strawberry farmers depend on toxic soil fumigants.

For decades, the use of the fumigant methyl bromide has allowed California’s strawberry industry to burgeon into the $2.6-billion industry it is today. California grows nearly 90 percent of the nation’s strawberries, many produced on Central Coast farms. But this lucrative industry comes at a cost. The colorless, odorless fumigant is a neurotoxin that can damage the brain, slow fetal growth and has been associated with an elevated risk of prostate cancer. It also diffuses into the stratosphere, where it damages the planet’s protective ozone layer.

Methyl bromide’s ozone-depleting properties are what led to its international ban under the Montreal Protocol, with a complete phase-out planned for 2005. But the treaty allowed for economic hardship exemptions, which California strawberry growers have eagerly embraced.  California strawberry growers received 90 percent of the exemptions issued globally in 2014, according to recent report from the Center for Investigative Reporting (CIR).

Today, California strawberry farmers use about half the methyl bromide they did 10 years ago. But the chemicals that are replacing methyl bromide are far from benign.

“These chemicals are highly volatile—and they are applied at hundreds of pounds per acre,” says Mark Weller, community organizer for Californians for Pesticide Reform. The volatility of fumigants is what makes them so effective at sterilizing soil. Because they vaporize into gas when they are injected underground, they quickly diffuse across the air space between soil particles, killing anything that lives there. But they also volatilize out of the soil and into the air.

Tarps are intended to slow down the release of fumigants, but they don’t stop the release. Different tarps have different levels of permeability, and some gas escapes through tarp edges. Gases also escape when a tarp is removed, accidentally torn or blown open by the wind.

“Poisonings from post-application drift have occurred at least a half mile away, and symptoms have been reported up to a couple miles away,” says Susan Kegley, principal scientist at the Pesticide Research Institute. She adds that many different pesticides have been found in High Sierra lakes, as well as within the bodies of frogs that live in the lakes.

Every few years there is a large-scale drift event in California caused by the volatilization of agricultural pesticides. A 2011 study showed that nine out of the 10 largest drift events from 1998 to 2006 were in California. The biggest drift event during that period occurred in 2005, when chloropicrin drifted into a residential area of Salinas, affecting more than 300 people who lived within 3 miles of the application site. Californians living in agricultural regions have a 69 times higher risk of poisoning from pesticide drift than residents of other regions.

Since the ban on methyl bromide, most California strawberry growers have simply switched to other toxic chemicals as pesticides. Use of soil fumigants overall has increased 20 percent over the past decade, according to the CIR report. This increase largely comprises the same two fumigants that poisoned field crews in the Salinas Valley incident in 2012— chloropicrin and 1, 3-D.

Chloropicrin was used during World War I as a vomiting gas—its high volatility allowed it to penetrate gas masks, forcing combatants either to choke on their vomit or rip off their masks, exposing them to additional chemical weapons. Chloropicrin irritates the eyes and respiratory system, and prolonged exposure damages lung tissue. Two laboratory studies have shown that chloropicrin causes tumors in mice and rats, and a Department of Pesticide Regulation toxicology report states “Due to the high toxicity of chloropicrin, it may be difficult to demonstrate its carcinogenicity or genotoxicity in vivo without affecting survival.” In other words, chloropicrin is so toxic that lab rats exposed to the chemical often die before they have a chance to get cancer.

More than 9 million pounds of chloropicrin were applied throughout California in 2012. It remains the highest-use pesticide as far as pounds applied in both Monterey and Santa Cruz counties.

The fumigant 1,3-D is recognized by the state of California as a carcinogen. For over a decade, the Department of Pesticide Regulation has allowed growers to exceed regulatory limits for 1,3-D, knowingly placing residents in over 100 California communities at a higher cancer risk. The fumigant has the third highest application rate in the state, with more than 12 million pounds applied throughout California in 2012.

Fumigants aren’t only used for strawberries; in the Central Coast region they are also used to grow raspberries, lettuce, spinach, carrots, wine grapes and brussels sprouts. And though fumigants are highly drift-prone, they aren’t the only pesticides that travel through the air. Monterey County’s $44.7-billion agricultural industry relies on a soup of chemicals. In 2012, more than 9 million pounds of pesticide active ingredients were applied in the county.

Silent effects

Gerardo Garcia carries his medical records in a backpack he wears slung over one shoulder. We meet at the transit center in Salinas, where he’s just bused in from Soledad, a farm-working community about an hour’s ride to the south. Garcia is on his way to Natividad Medical Center because he’s been feeling light-headed and dizzy again—a sign that he’s not getting enough oxygen. The 39-year-old can only walk short distances before he has to pause to catch his breath.

“I have a milky liquid in my lungs,” he says in Spanish, lifting his shirt to show the sutures in his chest that hold his skin together where doctors have taken two biopsies of lung tissue. “I don’t know exactly when it happened. The only thing the doctors told me is that what I have in my lungs was caused by many years of exposure to pesticides.”

Last year, Garcia was diagnosed with pulmonary alveolar proteinosis, a rare, incurable lung disease that has been associated with chronic pesticide inhalation. Garcia had been working in the fields since 1997, when he came to California from Guanajuato, Mexico. To stay busy year-round, he tended grapevines in the winter and harvested a variety of crops the rest of the year. Eventually, he worked his way up to a foreman position, and one of his duties was giving pesticide trainings to his field crew. He never had an incident of acute exposure that he knows of—just years of background exposure.

Garcia’s lungs are so debilitated that he can no longer work. The doctors say that in the near future he will likely need supplemental oxygen to survive. “People don’t know pesticides damage you because they don’t hurt,” he says. “I didn’t feel pain until recently when I couldn’t breathe … but the contamination adds up and it keeps growing and growing.”

In 1999, researchers from UC Berkeley began studying how pesticides affect the health of people living in the Salinas Valley. Through the university’s Center for the Health Assessment of Mothers and Children of Salinas—or CHAMACOS, which is an informal Mexican Spanish term for “little kids”—researchers have studied hundreds of Latino families, many with parents who work in agriculture.

Mothers in the study had higher levels of metabolites from organophosphate pesticides in their urine than women in the general population. Related to chemicals developed during World War II for nerve gas, organophosphates are neurotoxins. Children of mothers with the highest levels of organophosphates were more likely to have developmental problems, including abnormal reflexes, autism-related conditions, low IQ and indicators of attention deficit hyperactivity disorder, the study found.

Whether or not drift played a role in the mothers’ pesticide exposure is hard to tell, says Kim Harley, a professor of maternal and child health at UC Berkeley, and one of the study’s investigators. But another study looking at the dust inside the homes of participants correlated levels of the organophosphate pesticide chlorpyrifos in house dust with the amount of chlorpyrifos applied to nearby fields the month before.

“We know that chlorpyrifos doesn’t break down in the dust,” Harley explains. “It breaks down quickly outside in the sunlight and fresh air, but in dark places, like the dust balls under a bed, it can persist for a long time.”

This is significant for children living in agricultural regions because they are more affected by pesticide exposure than adults are, says Harley. “Children are a lot smaller than us. They eat, drink and breathe more per body weight than adults do. They are crawling on the floor and sticking their fingers in their mouths, so they have higher exposure from hand-to-mouth activity.”

She adds that young children are less able to break down some pesticides because they haven’t developed the necessary enzymes yet. And because childhood is a time of great brain development, children are extremely susceptible to the effects of neurotoxins.

A separate study by researchers at the UC Davis MIND Institute found that women in California who lived near agricultural fields where pesticides were applied when they were pregnant were more likely to give birth to children with autism spectrum disorder. And the rate increased with proximity: the closer a woman lived to a field, the higher her likelihood of having a child with the disorder.

A regulatory tangle

Kan, the CRLA attorney, frequently sees farmworkers and rural residents who have been sickened from pesticide volatilization—and, in many cases, no one is held accountable. If no pesticide application rules have been violated, the investigation is often dropped. “Basically, there is no comprehensive way of dealing with volatilization,” says Kan.

The problem is the Department of Pesticide Regulation’s Pesticide Drift Incident Response Policy, a document that gives a framework for County Agricultural Commissioners to use when investigating pesticide incident reports. The document clearly states, “Drift does NOT include the movement of pesticide and associated degradation compounds off the target area after the application, such as by translocation, volatilization, evaporation, or the movement of pesticide dusts or pesticide residues on soil particles that are windblown after application.”

When asked about the drift response document, Marylou Verder-Carlos, chief science advisor of Department of Pesticide Regulation, responded: “That policy has been updated.” But the wording on the actual document hasn’t changed—the updates are in the form of a compendium issued in 2009.

The compendium acknowledges that post-application movement of pesticides may occur, though it states, “The responsibility for off-site movement of pesticides is less clear. Volatilization is a characteristic of the pesticide itself, which cannot be controlled by the applicator.”

The compendium then refers County Agricultural Commissioners to state law, which consists of vague language that is open to interpretation. Pesticide applicators are directed to operate in a manner that prevents “substantial drift,” which is defined as a greater quantity of pesticide outside the target area than the quantity that would have resulted if the applicator had used “due care.”

Charlotte Fadipe, Department of Pesticide Regulation spokesperson, interprets the determination of due care by explaining that even if the pesticide is applied according to the label, drift may still have been foreseeable. “The County Agricultural Commissioner can still find a violation of off-site movement because maybe you could have foreseen that this would happen.”

In addition, she says, “If it was something that was foreseeable, anybody by law can go and file a lawsuit claiming negligence.”

“Even if it’s post-application drift, we’re going to investigate,” says Mary Lou Nicoletti, Santa Cruz County Agricultural Commissioner. “That being said, in following the pesticide rules and regulations, to give someone a violation or fine we have to have evidence the law or regulation has been violated.”

If the County Agricultural Commissioners don’t find any violations after investigating a case, the Department of Pesticide Regulation can review the case. “We look at the toxicology or another aspect of the chemical,” Verder-Carlos says,” and see if there are mitigations we should look at.”

Still, according to 2012 Pesticide Illness Surveillance Program data, in nearly half of agricultural pesticide-associated illnesses, there was no evidence of a safety violation—calling into question the adequacy of current regulatory controls.

Latino children disproportionately at risk

Ohlone Elementary School sits amid the strawberry and lettuce fields of North Monterey County, tucked behind a row of tall pine trees. Children dart across the playground, bouncing balls and climbing brightly painted play structures. Their shouts and laughter punctuate the still morning air. In the background, within a fenced-off area where the school garden used to grow, an R2-D2-looking machine quietly hums. Inside the inconspicuous white box is an air monitoring station that works like a human lung, with negative pressure drawing ambient air within. As air passes through, a sampling canister collects pesticides that drift across the playground.

The state installed the air monitor in 2011 as part of a settlement for a civil rights complaint, Angelita C. v. California Department of Pesticide Regulation. Angelita C., the parent of a 10-year-old student at Ohlone, banded together with five other Latino parents to represent the children and parents of six schools in agricultural areas of California. They filed a complaint with the federal Environmental Protection Agency in 1991, alleging that Department of Pesticide Regulation racially discriminated against Latino schoolchildren by allowing harmful levels of methyl bromide to be applied near schools populated mostly by Latino children.

Twelve years later, the EPA found that the Department of Pesticide Regulation had violated Title VI of the Civil Rights Act by disparately and adversely affecting Latino children. Internal investigations revealed that the children had been exposed to both short-term and chronic levels of methyl bromide above the EPA’s threshold of concern.

The EPA didn’t alert the families or their lawyers, however. And the agency didn’t provide any relief for victims of discrimination, or remedy for their complaints. Instead, they came to a settlement agreement, recommending that Department of Pesticide Regulation conduct air monitoring for two years and organize public outreach about the risks of pesticide exposure.

An Oxnard family that was involved in Angelita C. filed suit against the EPA in 2013 for its failure to enforce the Civil Rights Act. The case is now pending with the US 9th Circuit Court of Appeals.

In 2014, the California Department of Public Health released a report looking at agricultural pesticide use near schools in California. Monterey County ranked highest in the state for the percentage of students (25 percent) attending schools within a 1/4 mile of the highest pesticide applications.

Statewide, the study found that as the proportion of Latino children increased in the student population, the pounds of pesticides applied near schools increased. Latino students in Monterey County were 2.5 times more likely to attend a school near any pesticide use compared to white students—and 3.2 times more likely to attend schools near the highest pesticide applications. The study didn’t measure actual exposure in children or attempt to predict health outcomes. But still, teachers are concerned.

“The biggest thing is that it’s not something you’re going to wake up the next day and feel,” says Marcy Mock, who has been teaching special education at Ohlone for 14 years. “It’s something that’s going to affect you 20 years down the road. I think it’s really scary.”

Recently, Melissa Dennis, a third-grade teacher at Ohlone, took her students outside on a windy day. But when the dust was so heavy that she couldn’t see the classroom 50 yards across the quad, she shouted to all her students to run inside. “I closed the windows because I didn’t want to be breathing that,” she says. “Days earlier I’d seen people across from the school in full body suits, wearing gas masks, headgear, gloves and backpacks.”

Lack of transparency is one of the reasons people are scared, says Francisco Rodriguez, president of the district union, Pajaro Valley Federation of Teachers. “Notification would provide awareness. If a grower is taking precautions and a pesticide is determined to be safe, great—but we should be notified. Awareness is really key.”

There are no statewide regulations as far as notification, timing or method of application near schools. Instead, County Agricultural Commissioners set restrictions for each county. Because the Pajaro Valley school district straddles both Monterey and Santa Cruz Counties, the district deals with differing restrictions from each county commissioner. Both counties say they notify the district five days before a fumigation within 1/4 mile of a school, but not for other restricted pesticide applications.

Rich Buse, director of safety for the Pajaro Valley school district, says he alerts principals when he gets notification that a fumigation is scheduled near their respective schools. But there is no district policy that principals must notify staff. “It’s a recommendation,” says Buse.

Jared Boggs teaches math at Pajaro Valley Middle School, where rows of strawberries run perpendicular to the football field. The school is number two in the county for nearby pesticide applications, with more than 23,000 pounds of fumigants applied within 1/4 mile in 2010. Sometimes Boggs can smell the chemicals from his classroom. Yet, he says, “I have no memory of getting a notification.”

There are also no established state or federal health standards for concentrations of most pesticides that volatize into the air. Some pesticides, such as 1,3-D and methyl bromide, do have regulatory standards in place for air concentrations, but the vast majority do not.

The Department of Pesticide Regulation began monitoring for 32 airborne pesticides in three locations in California, including Salinas, in 2011. Later that year, as part of the civil rights settlement, the department began monitoring at Ohlone for methyl bromide and 1, 3-D.

In the absence of standards for airborne pesticides, the department developed health-screening levels (based on animal exposure studies) for the monitored pesticides. An internal memorandum reporting air-monitoring results explains,“ DPR primarily uses screening levels for pesticides for which it has not completed a comprehensive health evaluation (risk assessment) or established a regulatory goal.”

Health-screening levels are not regulatory enforceable standards. Department spokesperson Fadipe says they are more like a “check engine” light in your car. She explains, “Our screening level is our first indication that we’re beginning to see more of this pesticide than we want to see.”

In addition, monitoring sites are too few in number and too far from application sites, says Kegley. “The Salinas site is at the airport — It’s so far away from fields that we’re not going to see high levels. And it’s not even downwind from the fields. But we still do see levels of pesticides detected.”

Searching for solutions

As methyl bromide is phased out and the dangers of soil fumigants are becoming more clear, strawberry growers and researchers are conducting experiments to find alternatives to control soil borne pests without fumigants. The Department of Pesticide Regulation has allocated over $3 million in grants to support such projects at research facilities as well as smaller grassroots organizations.

Some alternatives under investigation include steam sterilization, soil solarization and the replacement of soil with different media such as peat, rice hulls and coconut fiber. Though the alternatives look promising, none have been identified that can be used on a large enough scale to support California’s current strawberry production.

Meanwhile, activists on the Central Coast have united to find ways to help protect children and the community. “One of our goals is to increase monitoring,” says Sarah Henne, a teacher on special assignment with the union. “We want more frequent monitoring and we want more monitors throughout the district.”

The union’s additional demands include at least a one mile* buffer zone around schools, a mandated 72-hour notice to schools prior to nearby pesticide applications, and an online public database showing pesticide use. “Like with crime statistics,” Rodriguez says, “we think there should be a statewide database so people can see trends of pesticide use and make an informed choice about where they want to live.”

“We want our food, we want it cheap – but there’s not enough attention to what’s happening to people in the community where the food is being produced,” says Boggs. “This is one situation where we need the government to step in and protect the people.”

*The story initially said that the requested buffer was 1/4-mile and has been corrected.

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