Agricultural Health Study Archives

July 25, 2024

Pesticide exposure as risky as smoking, study finds

By Shannon Kelleher

People who don’t farm, but live in US agricultural communities where pesticides are used on farms, face an increased cancer risk as significant as if they were smokers, according to a new study.

The study, published July 25 in the journal Frontiers in Cancer Control and Society, analyzed cancer incidence data from nearly every US county and looked at how that data corresponded to federal data on agricultural pesticide use. Researchers reported that they found the higher the pesticide use, the higher the risk for every type of cancer the researchers looked at.

“Agricultural pesticide usage has a significant impact on all the cancer types evaluated in this study (all cancers, bladder cancer, colon cancer, leukemia, lung cancer, non-Hodgkin’s lymphoma, and pancreatic cancer); and these associations are more evident in regions with heavy agricultural productivity,” the study states.

“Pesticide-associated cancers appear to be on par for several smoking-associated cancer types,” the study states. It has been well established that smoking increases cancer risk, with at least 70 of the thousands of chemicals in tobacco smoke considered carcinogens.

The findings add to a wealth of research on pesticides and human health risks that point to shortcomings in US pesticide regulations, said Dana Barr, and environmental health researcher at Emory University who was not involved in the study.

“Right now, I don’t think the regulations for pesticides are the most health-protective, and they seem to presume that a chemical is safe until it is proven toxic, not the other way around,” she said. “I do think we need policy reform that puts the onus on the manufacturers to do a better job of evaluating safety before allowing new registrations.”

October 27, 2022

Amid calls for ban on weed killer linked to Parkinson’s, a battle over science

By Carey Gillam

When US regulators issued a 2019 assessment of the widely used farm chemical paraquat, they determined that even though multiple scientific studies linked the chemical to Parkinson’s disease, that work was outweighed by other studies that did not find such links. Overall, the weight of scientific evidence was “insufficient” to prove paraquat causes the brain disease, officials with the US Environmental Protection Agency (EPA) declared.

The EPA reiterated its assessment in a 2021 report. The agency said after extensive analysis of numerous factors, including concerns about Parkinson’s risk, it determined farmers could safely continue to apply the weed killer across millions of US acres to help in the production of soybeans, corn, cotton and an array of other crops.

The determination has been significant for Syngenta, the longtime maker of paraquat weed killers. The company is facing calls in the US for a paraquat ban, as well as more than 2,000 legal claims brought by farmers and others alleging they developed Parkinson’s disease because of their exposure to paraquat.

Syngenta cites the EPA assessment of the science on paraquat in defense of the pesticide, and says scientific research “does not support” a causal relationship between the chemical and the disease. On a Syngenta-run paraquat information website, the company highlights several studies it says also backs that position, including many conducted by company scientists or by outside scientists who received company funding for their work.

Last week the Guardian and The New Lede reported that internal corporate records show Syngenta had knowledge of science linking paraquat to Parkinson’s decades ago but sought both to refute the evidence with various secret tactics. The documents are available at the Paraquat Papers Media Library.

US farmworker, health and environmental advocacy groups say in contrast to the corporate science, research conducted by independent scientists provides abundant evidence of paraquat’s ability to cause Parkinson’s and other health dangers, and the EPA is improperly discounting that body of research.

More than 50 groups have called for the US to follow the lead of dozens of other countries in banning paraquat. The Michael J. Fox Foundation for Parkinson’s Research submitted a petition to the EPA with 107,000 signatories calling for a ban. The foundation cited a study that found people exposed to paraquat in their teens or as young adults had an increased Parkinson’s risk of 200 to 600 percent, depending on the overall exposure.