Researchers at The Pennsylvania State University have found that people living in or near cultivated croplands face a significantly higher risk of melanoma, the deadliest form of skin cancer.

According to a Penn State news release, adults over age 50 who lived within a 15-county region in South Central Pennsylvania were 57% more likely to develop melanoma between 2017 and 2021. The increased risk was seen in both rural and metropolitan areas.

The findings challenge the assumption that melanoma risk is limited to farmers or those who spend long hours outdoors in remote settings, says Dr. Charlene Lam, a board-certified dermatologist with Penn State Health and co-author of the study.

“Melanoma is often associated with beaches and sunbathing, but our findings suggest that agricultural environments may also play a role,” she said. “And this isn’t just about farmers. Entire communities living near agriculture, people who never set foot in a field, may still be at risk.”

The study, published in JCO Clinical Cancer Informatics, accounted for ultraviolet radiation levels across Pennsylvania as well as socioeconomic factors that can influence cancer rates. Even after these adjustments, the researchers found clear patterns: counties with more cultivated cropland and higher herbicide use consistently reported higher melanoma rates.

Previous studies have raised concerns that agricultural chemicals may contribute to skin cancer risk through direct exposure or by contaminating the surrounding environment. Certain chemicals can increase light sensitivity, disrupt the endocrine and immune systems, and cause DNA damage in animals and plants.

The Penn State analysis found that every 10% increase in cultivated land corresponded to a 14% rise in melanoma cases. A 9% increase in herbicide use was linked to a 13% increase in melanoma incidence.

Lam emphasized that the elevated risk extended beyond agricultural workers. Chemicals can drift through the air, enter water systems, and settle into nearby homes. “You don’t have to be a farmer to face environmental exposure,” she said. “Our findings suggest that melanoma risk could extend beyond occupational settings to entire communities.”

Although the study does not prove a direct cause-and-effect relationship between agricultural chemicals and skin cancer, researchers say the correlation warrants deeper investigation.

“The data suggest that areas with more cultivated land and herbicide use tend to have higher melanoma rates, but many other factors could be at play like genetics, behavior or access to health care,” noted Benjamin Marks, co-author and a medical student at Penn State College of Medicine. “Understanding these patterns helps us protect not just farmers, but entire communities living near farmland.”

Lam added that similar associations have been reported in agricultural regions of Poland, Italy, and parts of Utah. She advises people who are concerned to perform regular skin checks and to use sun-protective clothing and sunscreen.

While ultraviolet radiation remains the primary risk factor for melanoma, the authors say the new findings underscore the need to better understand how pesticides and other farming chemicals may interact with sun exposure to increase skin cancer risk.