A new report released Wednesday identifies links between environmental risk factors, including pesticides, PFAS, known as “forever chemicals,” nitrates and radon with increased cancer incidence and risk for numerous cancer types.

“Iowa has some of the highest nitrate levels in drinking water in the U.S., extensive and intensive pesticide use, elevated radon concentrations in homes and emerging concerns about PFAS contamination,” according to the report.

The report, titled “Environmental Risk Factors and Iowa’s Cancer Crisis,” was developed by the Iowa Environmental Council and the Harkin Institute for Public Policy and Citizen Engagement. The report used a mixed-methods research approach combined a literature review, qualitative data from Iowans gathered through listening sessions, and analysis of cancer and environmental data.

“While there is public awareness that behavioral factors such as smoking, alcohol consumption and exposure to UV light from the sun or tanning beds can cause cancer, environmental factors – what is in our water, soil, and air – are discussed far less,” the report said.

Report authors said they learned that all the most common cancers in Iowa (breast, prostate, lung, colorectal and skin melanoma) have associations with environmental risk factors (pesticides, nitrate, PFAS and radon.)

At a press conference held Wednesday, Sarah Green, executive director of the Iowa Environmental Council, said at the listening sessions held across the state they began by asking if attendees or a loved one has been diagnosed with cancer.

“Every time, every hand went up,” Green said. “That moment tells you everything you need to know about the scale of this crisis in Iowa. Cancer is touching every corner of the state. It cuts across geography, age and background, rural and urban, young and old, and behind those raised hands are stories that are just as heartbreaking as they are urgent.”

Iowa has the second-highest cancer incidence rate in the nation and is one of two states where the rate is rising. 

“While the U.S. has a declining overall cancer rate, Iowa’s is sharply increasing,” the report said. 

According to the report, Iowa has some of the highest pesticide application rates in the nation with the fourth-highest use of pesticides by weight between 2015-2019, exceed by California, Florida and Illinois. 

“Iowans come into contact with pesticides through drinking water, food residues, pesticide drift from fields, house dust and other occupational exposure,” the report said.

Adam Shriver, director of wellness and nutrition policy at the Harkin Institute, said that although the environment is not the only factor driving Iowa’s high and rising cancer rates, “it is absolutely clear” Iowans experience exposure to environmental risk factors for cancer “at levels not seen elsewhere in the United States.”

“Cancer is complex, and we need to work to reduce all of the risks connected to it,” he said.

The latest Cancer in Iowa report produced by the Iowa Cancer Registry, provided updated data, including an estimated 21,700 new cancer diagnoses expected among Iowans this year.

This year’s report also featured research on cancer rates in Iowa farmers. Farmers who apply pesticides are considered to be “highly exposed” to pesticides compared to the general population, so studying this population makes it more likely that researchers will be able to detect relationships between pesticide exposures and cancer risk when they exist, according to the report.

Iowa farmers in the study had 13% fewer cancers overall than expected compared to the general population in Iowa from 1994-2015. While the farmers’ study identified several pesticides that are associated with a higher risk of cancer in the most highly exposed farmers and spouses, lower rates of smoking and alcohol consumption among farmers and their spouses likely contributed to a lower burden of many cancers. 

The environmental risk factors report also charts links between cancer and nitrates.

“Nitrate load in Iowa’s waterways has grown over time, and concentrations continue to increase,” the report said.

It noted that the Des Moines and Raccoon rivers rank in the top 1% of rivers nationwide for nitrate concentration, with 80% originating from agricultural sources. 

“A growing body of evidence shows that nitrate levels far below the EPA standard [of 10 milligrams per liter] are associated with increased risks of cancer including colorectal, ovarian, bladder, thyroid and prostate cancer,” the report said. “One study observed a 200% increased risk of colorectal cancer among individuals consuming well water with nitrate concentrations above 2.5 milligrams per liter.”

The report included a range of policy solutions, such as asking the Iowa Department of Natural Resources to adopt standards for carcinogens in water, air, and soil that “protect public health and work across sectors to implement effective and efficient strategies” to limit exposure.

It also called for more environmental monitoring and transparency. 

“Iowa’s state agencies must partner with universities, federal stakeholders, local governments, and Iowans to implement systems that result in transparent and accurate monitoring and public reporting on the most concerning sources of carcinogens in Iowa’s water, air, and soil,” the report said.

Kerri Johannsen, senior director of policy and programs with the Iowa Environmental Council, said the group has advocated that Iowa lawmakers this session fund the Iowa water quality monitoring network at the University of Iowa hydroscience and engineering department.

“This is a network that gives us information about whether our water quality is improving or getting worse, which is something that is really important for us to know,” she said. “Right now, if those sensors are not funded, they are slated to go offline this summer.”