Oct. 18, 2019
There isn't enough evidence to conclude paraquat causes Parkinson's Disease, the US Environmental Protection Agency said in a health effects assessment released Tuesday.
For occupational exposures, "there is limited, but insufficient epidemiologic evidence of a clear associative or causal relationship," EPA said in the human health effects document. The agency's draft ecological risk assessment identifies potential risks to mammals, birds, adult honey bees, terrestrial plants, and algae.
EPA based its conclusion on Parkinson's "on mixed findings in both the [Agricultural Health Study] cohort and other study populations. These studies may all be subject to uncertainty due to limitations in their design, exposure assessment approach, and potential for bias."
The Center for Biological Diversity swiftly criticized the Parkinson's conclusion. "EPA's analysis discounted considerable evidence that paraquat has been shown to more than double the risk of developing Parkinson's disease in farmworkers and others suffering occupational exposure," the group said.
The assessments carry a 60-day comment period and are part of EPA's registration review of the widely used herbicide.