For the first time in almost 40 years, the U.S. Environmental Protection Agency has issued an emergency order to stop the use of a pesticide that can cause irreversible damage to fetuses.
The pesticide dimethyl tetrachloroterephthalate, also known as DCPA or Dacthal, is used as a weedkiller on crops like strawberries, broccoli, Brussels sprouts, cabbage and onions. But when a pregnant woman is exposed to it, the chemical can alter fetal thyroid hormone levels, and those changes can cause irreversible effects like low birth weight, impaired brain development, decreased IQ and impaired motor skills later in life, the EPA said in its announcement.
"DCPA is so dangerous that it needs to be removed from the market immediately," said Michal Freedhoff, assistant administrator for the Office of Chemical Safety and Pollution Prevention. "It's EPA's job to protect people from exposure to dangerous chemicals. In this case, pregnant women who may never even know they were exposed could give birth to babies that experience irreversible lifelong health problems."
DCPA has been on the market since 1958, but for several years, the EPA has been requesting data from the pesticide's sole manufacturer, AMVAC Chemical Corporation, to ensure its safety for humans and the environment.
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In 2013, the EPA required AMVAC to submit more than 20 studies, including on DCPA's effect on thyroid development in fetuses and adults, to support its registration by 2016. But the agency said multiple submitted studies were insufficient, and studies on thyroid effects weren't submitted at all.
Ten years later, after AMVAC had submitted the thyroid study the year prior, the EPA released an assessment linking DCPA use with health risks, most seriously to fetuses and pregnant women, even when the user wore protective gear. This revealed some pregnant women could expose their fetuses to four to 20 times the safe level of DCPA if they'd handled DCPA products.
The EPA issued a public health warning in April stating its intent to pursue action due to the identified health risks. It issued the order Tuesday under the Federal Insecticide, Fungicide and Rodenticide Act. Because of DCPA's risk, the suspension will be effective immediately.
Within 90 days, the EPA said it would issue a notice of intent to permanently cancel DCPA products. The process of fully eliminating such chemicals can take months or years.
Environmentalists, like the Environmental Working Group, say the decision to suspend DCPA is "welcome news, but it's long overdue," citing an EPA document in which the chemical was listed as a possible human carcinogen in 1995.
"For years, EWG and other public health advocates have warned about the serious risks the weedkiller poses to farmworkers, pregnant people and other vulnerable populations," said Dr. Alexis Temikin, EWG senior toxicologist. "Countless people have been exposed to DCPA while the EPA abdicated its responsibility. The agency should have taken action decades ago, when it first identified the human health risks posed by this toxic crop chemical."
