Sweden started ringing the alarm bell more than 40 years ago, banning the weed killing chemical paraquat in 1983. One by one, other countries around the world did the same as evidence of paraquat risks to human health mounted. Even the Chinese government, which owns the longtime paraquat maker Syngenta, halted use of the pesticide a decade ago after conducting its own studies on paraquat safety and finding troubling results.

In the US, Vermont also recently banned paraquat, with lawmakers there citing risks that include an association between paraquat and Parkinson’s disease shown in years of scientific research.  And California regulators announced paraquat makers voluntarily agreed to stop selling the chemical after the state identified health concerns in new research. Several federal lawmakers have pushed for a nationwide ban.

Yet amid the global cloud of concern, the US Environmental Protection Agency (EPA) continues to greenlight paraquat use on millions of acres, and has downplayed the significance of science linking paraquat to Parkinson’s, an incurable brain disease. The agency said in June it would hold a roundtable over the summer to re-examine the “safety challenges” associated with paraquat. But no such event was held or has been scheduled.