Vermont has become the first U.S. state to ban the herbicide paraquat, with Governor Phil Scott signing legislation on Tuesday citing concerns about studies linking the chemical to Parkinson's disease.

The new law, which takes effect November 1, prohibits the use of paraquat based on research indicating the weedkilling pesticide substantially increases the risk of developing Parkinson's disease, an incurable neurological condition that affects movement and coordination.

The legislation includes a limited exception allowing state regulators to issue special permits for paraquat use on fruit-producing tree orchards, berries, and other small fruit crops through December 31, 2030. This provision provides a transition period for agricultural operations that may rely on the chemical for specific crop protection needs.

Paraquat is widely used in commercial agriculture as a herbicide to control weeds and grasses. The chemical has faced increasing scrutiny from public health advocates and researchers who have documented associations between exposure and elevated Parkinson's disease rates.

Vermont's action comes as pressure mounts for broader restrictions on paraquat use across the United States. The state's ban represents the most significant regulatory action taken against the herbicide at the state level, potentially setting a precedent for other jurisdictions considering similar measures.