EPA’s Immediate Ban on Dangerous Herbicide: A Closer Look
In a rare and urgent move, the U.S. Environmental Protection Agency (EPA) has issued an immediate ban on the herbicide DCPA, commonly known as Dacthal. This decision follows significant concerns about the chemical's impact on human health, particularly for pregnant women and their unborn children. The ban comes after DCPA, which has been used for nearly 70 years, was found to pose serious health risks, including potential harm to fetal brain development.
The Ban and Its Justification
Immediate Action and Health Risks
The EPA's emergency order, announced on Tuesday, represents a rare regulatory intervention, marking the first such action by the agency in nearly 40 years. The decision to suspend all use of DCPA was driven by evidence that the chemical can adversely affect the developing brains of babies in the womb. Assistant Administrator for the Office of Chemical Safety and Pollution Prevention, Michal Freedhoff, emphasized the severity of the risk, stating, “It’s EPA’s job to protect people from exposure to dangerous chemicals.”
Despite these urgent measures, the EPA's findings on the herbicide's risks are not entirely new. The agency had previously identified DCPA as potentially harmful to fetal thyroid levels, which can lead to low birth weight, impaired brain development, decreased IQ, and motor skills deficits—some of which may be irreversible.
Historical Context and Advocacy
Advocates have long criticized the delay in banning DCPA. The chemical was labeled a "possible human carcinogen" by the EPA in the 1990s, and the European Union had already banned it fifteen years ago. Alexis Temkin, Senior Toxicologist at the Environmental Working Group, described the emergency order as “welcome news, but it’s long overdue,” highlighting ongoing concerns about the chemical’s health risks.
Use and Contamination in California
Prevalence and Application
DCPA has been used extensively in California, particularly on crops such as broccoli, onions, Brussels sprouts, and cabbage. According to recent federal data, California growers used nearly 200,000 pounds of DCPA in both 2021 and 2022, out of less than half a million pounds used nationwide. The highest concentrations of use were reported in Monterey County, where studies revealed that over half of nearly 100 Latina girls aged 14 to 16 living in farmworker communities had been exposed to DCPA.
Groundwater Contamination
Traces of DCPA have been detected in groundwater in various California farm regions. The state Department of Pesticide Regulation found concentrations of breakdown products of DCPA ranging from 66 to 159 parts per billion in wells near Guadalupe in Santa Barbara County, and up to 101 parts per billion in a well near Greenfield in the Salinas Valley. Although these levels are below the state’s health-protective drinking water limits, they have raised concerns, particularly in light of new studies showing potential birth effects.
Regulatory Response and Industry Reactions
State and Federal Coordination
The California Department of Pesticide Regulation (DPR) has stated that it lacked sufficient information to independently ban DCPA and would have needed to conduct its own risk assessment and regulatory process, which could have taken months or years. Leia Bailey, the department's deputy director of communications and outreach, noted that the EPA's action had expedited the process of addressing the chemical's risks.
Industry Compliance and Ongoing Review
AMVAC Chemical Corp., the manufacturer of DCPA, has stated its compliance with the EPA's emergency order. Anthony Young, AMVAC's director of investor relations, confirmed that the company had voluntarily withdrawn the herbicide from the market in May and is working to ensure that its products are no longer used.
The EPA’s decision follows a protracted review process, during which AMVAC missed several deadlines for submitting critical data. The agency has been pushing for this data since 2013, including studies on thyroid function in fetuses and children. The delayed submissions prompted the EPA to issue a temporary suspension before the final ban.
Addressing Health Risks
The EPA's immediate ban on DCPA underscores the serious health risks associated with the herbicide, particularly for vulnerable populations such as pregnant women and their unborn children. The move reflects a growing recognition of the need to protect public health from dangerous chemicals, even as it highlights ongoing concerns about the timeliness of such regulatory actions. As California grapples with the fallout from this ban, the focus will now shift to monitoring the impacts of DCPA's removal and ensuring that such health risks are addressed more promptly in the future.