Iowa county seeks answers on high cancer rates

The family farm where Horsley grew up was one of more than 1,200 farms in Palo Alto County in 1970. In her memory, the county’s 13,000 residents enjoyed a thriving agricultural-based economy and close-knit neighbors. Cows grazed in verdant pastures. And seemingly endless acres of corn marched to the horizon.

“We had good crops, corn and soybeans,” Horsley said of her family’s farm along the West Fork of the Des Moines River. “You could make it on a small amount of farmland. You felt safe. It was a good life.”

Two generations later Emmetsburg and Palo Alto County have been radically transformed into a place where many residents worry that the farms that have sustained their livelihoods are also the source of the health problems that have plagued so many families.

Horsley, a certified nurse practitioner who still lives in the county, is among many Iowa residents who ask whether the farms that make up the lifeblood of Iowa’s economy have become a source of disease and death due to the toxic chemicals and other pollutants indelibly linked to modern agricultural practices.

“We drank the water on our farm,” Horsley said in an interview. “My sister had breast cancer. She was only 27 when she died. She grew up here. My other sister had uterine cancer. As a nurse practitioner I’m aware of five people now with pancreatic cancer. I know 20 people who have other cancers or died of cancer here. Look at the obituaries in our newspaper. Everybody is aware this is going on.”

Palo Alto’s 2022 tally of 842 farms generates nearly $800 million in annual market value. But nearly 400 small farms have been absorbed into bigger operations or otherwise stopped operating over recent decades, and Palo Alto’s population has dropped by 4,200 people since 1970.

Today’s Iowa farms are largely focused on raising hogs and growing corn, both of which are linked to numerous environmental problems. Farmers growing corn, for example, often rely heavily on applications of toxic pesticides and fertilizers, while livestock operations generate millions of tons of manure annually. The chemicals and manure pollute food and water consumed by people even far from farm fields.

When nitrogen from fertilizer and manure combine with oxygen they create nitrates, which routinely drain from farm fields into groundwater, streams, and rivers, contaminating water sources. Babies can suffer severe health problems when consuming nitrates in drinking water, and a growing body of literature indicates potential associations that include an increased risk of cancer. Exposure to elevated levels of nitrates in drinking water has been linked by researchers to cancers of the blood, brain, breast, bladder, and ovaries.

As well, there are years of research showing that many herbicides and other pesticides applied to farm fields are linked to cancer and other diseases. The National Cancer Institute and the National Institute of Environmental Health Sciences have been funding research to investigate the links between disease and farming for more than 30 years, focusing their work on people in Iowa and North Carolina. Among the findings are links between pesticides and malignant brain tumors, multiple myeloma, pancreatic cancer, and certain breast cancers.

Concerns about connections between the farm pollutants and cancer have been mounting, particularly in Palo Alto County, which had the highest incidence of cancer of any county in the state and the second-highest incidence of cancer among all US counties, with 83 new cases of cancer on average each year, in a population of 8,996, according to a 2023 report by US News.

The five-year incidence rate for cancer in Palo Alto County is 658.1, far higher than the national five-year average of 442 new cancer cases reported for every 100,000 people, according to the National Cancer Institute.

The concerns are not limited to Palo Alto County: Iowa has the second-highest and fastest-rising cancer incidence among all US states, according to a 2024 report issued by the Iowa Cancer Registry. Cancer incidence in Iowa stayed mostly steady from 2001 to 2010, then dropped briefly before starting an upward climb after 2013, according to federal data.

Medical experts and state health authorities say it is difficult to pinpoint exactly what may be causing the prevalence of cancer in Palo Alto and Iowa overall. But many residents believe there is little doubt that the answers lie in the tide of farm pollutants pervading the environment.

“We are so heavily into agriculture in Iowa,” said Horsley. “Big chemical use. Big nutrient applications. What effect is that having on people? There needs to be more research on that.”

David Dunn and his wife, Sharon Kendall-Dunn, reside in Davenport, some 300 miles south and east of Palo Alto County. Still, they wrestle with their own concerns about the impacts farming and farm-related pollution may have on their health. Ten years ago the couple learned that a mass in David’s abdomen was non-Hodgkin lymphoma, a cancer common in farm country nationally. 

Though the couple did not work or live on a farm, their doctor indicated the environment could be to blame. Sharon remembers that when she asked the doctor how her husband could have gotten the disease, he told the couple simply: “You live in Iowa.” 

Two years ago Sharon was also diagnosed with cancer, a type called chronic myeloid leukemia, which begins in the bone marrow. So far, treatment has helped keep her disease under control.

“I was in so much pain,” she said. “It’s better now.”

David’s cancer is also undergoing treatment. But the impact on his life and his future has been dramatic. 

“This is some kind of crazy,” said David. “I stopped dreaming. I stopped dreaming about retirement. I stopped dreaming about the kids graduating from college. I didn’t think I’d see them get married. I didn’t think I was going to hold a grandkid.”

Both Sharon and David grew up in Iowa. Other friends and family members have also been diagnosed with cancers, and some have died. 

In the tiny farming town of Long Grove, Chris Green mourns the 2019 death of her husband, who was stricken by the deadly brain cancer known as glioblastoma. With aggressive treatment, Jim Green lived nearly two years following his diagnosis but ultimately succumbed.   

“He said to me, ‘You know, I can’t do this anymore.’” Chris recalled. “So we had hospice come in. Jim passed in the living room… surrounded by family.”

Before he died at age 65, Jim worked nearly 39 years on the maintenance staff of an aluminum plate rolling mill in Davenport. His exposures to various industrial chemicals there could have been a factor in his disease, but some studies also link pesticides, such as those used commonly on farms, to glioblastoma.

Chris said she knows of at least nine other people in her community who have died from glioblastoma in the last several years.

“What you’re seeing in Iowa is a problem,” said Molly Jacobs, an epidemiologist at the University of Massachusetts. “You can see it from the experience on the ground. The message from me is to put energy into reducing exposure to the known harms.”