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Reigniting controversy, EPA issues use particulars for paraquat


Photo: fatihhoca/iStockphoto

Washington — The Environmental Protection Agency on Aug. 1 reapproved the use of the toxic herbicide paraquat in limited aerial applications, reigniting debate over the controversial, restricted-use substance that has been linked to an increased risk of Parkinson’s disease among agricultural workers.

Used annually for weed control and as a defoliant on certain crops before harvest, paraquat can be administered only by certified applicators. The agency’s interim decision reverses course on a draft interim decision issued in October that proposed a ban of all aerial applications other than those for cotton desiccation.

EPA’s actions under the interim decision, which is final, include:

  • Limiting aerial applications to a maximum of 350 acres per applicator per 24 hours for all uses apart from cotton desiccation.
  • Requiring 50- to 75-foot residential buffers for all aerial applications.
  • Prohibiting pressurized handgun and backpack sprayer applications.
  • Requiring enclosed cabs for applications to more than 80 acres in a 24-hour period.
  • Requiring enclosed cabs or respirators for applications to 80 acres or fewer in a 24-hour period.
  • Increasing the Restricted Entry Interval for several crops.

“The agency has taken proactive steps to ensure paraquat is used in a manner that will not cause unreasonable adverse effects to human health or the environment and is consistent with the label directions,” EPA says.

A 2011 study found that workers who are exposed to paraquat have more than double the risk of developing Parkinson’s disease. However, an updated study in 2020 “did not replicate” the findings, according to EPA, which acknowledges “many studies on paraquat and Parkinson’s disease that range in quality and provide conflicting results.”

EPA says that, after reviewing “the best available science” – as required under the Federal Insecticide, Fungicide, and Rodenticide Act of 1947 – the agency “has not found a clear link between paraquat exposure from labeled uses and adverse health outcomes such as Parkinson’s disease and cancer.”


A press release from the nonprofit Center for Biological Diversity cites 2019 research from the environmental group showing that paraquat, which is banned in the European Union, China and Brazil, “has resulted in the deaths of at least 30 people” in the United States over the past 30 years.

“It’s extremely disappointing that the Biden EPA is reapproving this dangerous pesticide, which is outlawed across a lot of the world,” Nathan Donley, environmental health science director at the center, said in the release. “Instead of banning a weed killer linked to Parkinson’s disease in farmworkers, reproductive harm in small mammals and increased death rates for birds, this administration is bowing to the wishes of the chemical industry and allowing it to be sprayed on crops from the air. This is a huge step in the wrong direction for a president who insists he’s prioritizing both environmental health and environmental justice.”

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