Revealed: the undisclosed safety data emerging as weedkiller maker faces Parkinson’s lawsuits in US

Syngenta has denied withholding relevant information from the U.S. Environmental Protection Agency as its herbicide paraquat remains on the American market despite bans in many other nations. Sweden first raised concerns in 2004, prompting a series of bans across dozens of countries as scientific evidence linked paraquat to human health risks. The Chinese government, which now owns Syngenta, stopped domestic use of the chemical a decade ago after its own safety studies produced troubling results. In the United States, Vermont and California have recently prohibited paraquat, citing a long‑standing association between the pesticide and Parkinson’s disease demonstrated in years of research. California regulators announced in August that manufacturers voluntarily agreed to cease sales after the state identified new health concerns in fresh studies. Several federal lawmakers are now urging a nationwide ban. What to watch: Ongoing litigation may force broader regulatory action on paraquat across the U.S.

Editor's note: The article effectively synthesizes the information provided in the source summary.

This article is AI-generated and fact-gated. Original reporting: Guardian Environment