Isaret Jeffers-Chavez of Colectivo Arbol offers masks and face shields to farmworkers in Florida in 2021.Ivy Ceballo/Tampa Bay Times/ZUMA
Last week, the Environmental Protection Agency announced it was permanently suspending its approval of the widely used pesticide, Dacthal, amid a barrage of evidence of damaging, lasting effects on reproductive and fetal health—most notably among pregnant farmworkers. It is the most significant action the agency has taken on a pesticide in decades.
Dacthal, the trade name of dimethyl tetrachloroterephthalate (DCPA), is used to prevent weeds from growing and has been used on a variety of crops like strawberries, spinach, celery, and garlic since the late 1950s.
The historic action comes after years of delays, mostly on the part of its manufacturer, the agricultural conglomerate AMVAC, which took 11 years to submit full data on its product—forcing the EPA to delay its decision on the chemical. The agency classified the chemical as a potential carcinogen in 1995; it has been banned in the European Union since 2009.
“We’ve known for quite a long time that [Dachtal] is really precarious in terms of exposure to mothers during pregnancy or in the preconception period,” said Carmen Messerlian, a reproductive health scientist at Harvard University’s T.H. Chan School of Public Health. “The data is pretty conclusive, showing significant risk to unborn fetuses, specific outcomes related to neurodevelopmental problems, as well as low birth weight and IQ.”
“We’re happy that they’re going to suspend it. That’s a really big step, because I think it’s been 40 years since EPA has taken a step like that to suspend a pesticide,” said Jeannie Economos, coordinator of the Pesticide Safety and Environmental Health Program of the Farmworker Association of Florida.
“We know that the bureaucratic process is long, we know that EPA does have to negotiate with [AMVAC], so we take that all into consideration, and we’re grateful for all the work that went into it,” said Economos. “But at the same time, it is terrifying that these pesticides are allowed in the market in the first place.”
Another harmful aspect of DCPA is how long it lingers on and around crops and fields treated with the pesticide. Its manufacturer claims that fields treated with Dachtal are safe to enter after 12 hours—but the EPA said it had evidence that fields retained unsafe levels of the pesticide for up to 25 days.
It also tends to travel beyond the crops it’s intended to work on. This concept, called pesticide drift, also means that workers and adjacent communities are at risk because of the toxicity of DCPA—especially given that its labeling downplays that risk.
Pesticides like DCPA remain on the market even as scientific evidence increasingly confirmed carcinogenic and other detrimental health impacts in part because such products, by default, are treated as safe unless shown otherwise. The onus is on agencies like the EPA and FDA to gather direct scientific evidence that products do harm, not on the manufacturers to prove they don’t.
That dynamic doesn’t exist in much of Europe, or in Canada; under those systems, any evidence-based concerns about the safety of industrial products, like pesticides, necessitate that manufacturers prove the product is safe before exposing the public to it.
“I think DCPA is a really good case study about how the pesticide regulatory system is really broken,” said Alexis Temkin, a senior toxicologist at the Environmental Working Group, an advocacy organization that works to protect human and environmental health from toxic chemicals.”It’s supposed to be that the most vulnerable are protected—that’s the most highly exposed, like farmworkers and the most sensitive, like pregnant people and children time and time again, we’ve seen it play out that that’s not necessarily the case.”
Temkin has been studying DCPA since 2018, when she analyzed USDA data which eventually showed how prevalent it was in kale. She was concerned that people attempting to eat healthier might be exposed to more of a toxic chemical than they realized.
“About 60 percent of those kale samples” contained DCPA, Temkin said. “As soon as I started investigating what the health effects were, we started to see: it had impacts on the thyroid, as well as the liver and lungs.”
Messerlian points out that despite regulatory inaction, responsibility for DCPA’s continued harm to the public lies with its manufacturer. AMVAC “failed to do due diligence to protect the public,” she said. “Thousands of babies have been exposed. Mothers have been exposed, fetuses have been exposed, and the cost of that is human life, human suffering, at the benefit of companies that continue to profit off agricultural workers.”
