Older adults who live in southcentral Pennsylvania have higher rates of melanoma skin cancer, according to a study by Penn State researchers that found that counties with more farmland and herbicide use also have more melanoma, and not just among farmers.
"Our results showed that there was a strong signal or pattern that counties that had high melanoma rates also had higher amounts of agriculture, specifically cultivated crops," said Benjamin Marks, who is in his last year as a medical student at the Penn State College of Medicine and is first author of the paper. "And those counties also with high melanoma had an increased proportion of acres that were treated with pesticides, with herbicides showing the highest pattern.
The researchers analyzed five years of data for adults 50 and older in Pennsylvania. They looked at the percentage of land used for agriculture and the proportion of acres treated with pesticides and herbicides.
Even after adjusting for UV levels and socioeconomic factors, what emerged was a 15-county “hotspot,” which includes Centre County. They found that the adults in that cluster were 57% more likely to develop melanoma, the deadliest type of skin cancer.
“We're unable to say what is exactly causing the increased melanoma, but what we can say is that counties with high melanoma also had high agriculture, specifically croplands, row crops, and also had higher herbicide use," Marks said.
Marks cautioned that the study did not find that agriculture is causing the higher melanoma rates and there may be other factors involved.
"The takeaway — we don't want it (to cause) a panic — but it’s that people in these counties, especially older adults who might be outdoors more or might be exposed to pesticides, should be more intentional about sun protection and skin checks," Marks said.
He says he hopes to see more research into the topic. The findings were published in JCO Clinical Cancer Informatics.
