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California pressured to ban paraquat

Groups claim common herbicide is harming agricultural communities

by Britt E. Erickson
November 10, 2022 | A version of this story appeared in Volume 100, Issue 40


Chemical structure of paraquat.

Environmental groups are urging California to ban the herbicide paraquat, which is acutely toxic and lethal if ingested. Several studies have also linked paraquat exposure to Parkinson’s disease.

In a letter to California pesticide regulators, the Center for Biological Diversity and Californians for Pesticide Reform call for immediate suspension of paraquat, claiming that “the continued use of this pesticide presents immediate substantial danger to human health and the environment.”

Use of paraquat in the US has doubled in the last decade, the groups say. California is one of the biggest users. The herbicide is banned in dozens of countries because of risk to farmworkers.

Last year, the US Environmental Protection Agency announced that paraquat could stay on the market with new safety measures to protect agricultural workers. The Center for Biological Diversity and other environmental groups sued the EPA, challenging that decision. In September, the EPA told the court that it needs to reevaluate paraquat’s risks and benefits and its potential to volatilize. The case is ongoing.

Meanwhile, companies that make and distribute paraquat are facing a flood of lawsuits from agricultural workers who claim they developed Parkinson’s because of exposure to the herbicide. The number of cases is approaching 2,000 and growing rapidly.


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