Iowa’s cancer rates remain the second highest in the nation

Cancer rates in the state of Iowa and Montgomery County continue to be on the rise.
Recently, the Iowa Environmental Council, in partnership with the Iowa Farmer’s Union, and the Nishnabotna Water Defenders hosted a special session on the “Environmental Risk Factors and Iowa’s Cancer Crisis” at the Red Oak Public Library.
Discussion was led by Colleen Fowle, the water program director at the Iowa Environmental Council, and Kerri Johannsen, the senior director of policy and programs. The goal of the session was to share the research that examines how environmental health may be playing a role in Iowa’s ongoing cancer crisis, spark discussion about what is happening in the state and listen to how that is impacting people’s lives. Fowle said the news regarding cancer rates in Iowa was not good.
“For the second year in a row, Iowa was ranked second for the rate of new cancers in the U.S, and we’ve been number two ever since 2024. We are also only one of three states where the rates are increasing. Experts are clear that multiple factors contribute to a person’s cancer risk. However, while some risk factors are well known and openly discussed, like lifestyle choices such as smoking, alcohol consumption, and tanning, other potential causes were not part of the discussion. And that’s what motivated us at the Iowa Environmental Council to undertake a rigorous review of the scientific research about the environmental risk factors associated with cancer so we can get a fuller picture of the cancer in our state,” advised Fowle.
The IEC published a report this past March entitled Environmental Risk Factors in Iowa’s Cancer Crisis.  The IEC convened a panel of scientific experts, including those from environmental health, epidemiology, and oncologists, to help focus the report and take into account what they have heard from Iowans during listening sessions held last summer.
“We reviewed over 250 studies and analyzed data from long-term research that was published in professional journals over the course of the year. We also went through a very rigorous review process that involved more than two dozen state and national experts who provided feedback on various drafts of the report before publication. For the first time, it summarized the most concerning environmental risk factors for cancer in Iowa and their relationship to our cancer rates,” commented Fowle.
Johanssen spoke to the attendees about the cancer in Iowa statistics, pesticides, and PFAS-synthetic chemicals used in products like non-stick cookware, water-resistant fabrics, and food packaging, as well as nitrates and radon. Johanssen said sometime between 2012 to 2014, something started to change in our state.
“Iowa’s rates started to climb even as national rates overall were declining. There are many things that can increase the risk of developing cancer, including the lifestyle factors we mentioned earlier. There are also things in our environment that, when we are exposed to them, can lead to cancer. Our body, of course, is always making new cells, right? Cell replication is a part of something that we do all the time. And mutations are also pretty normal, and our immune system typically can come up and fix those mutations as they happen, and they do not develop into cancer,” explained Johanssen. “However, when we’re exposed to carcinogens in the environment, they can act on our body in a couple of ways. One, they can increase the mutations so that we are getting more mutations happening more often. They can also suppress our immune response so that the little guys who used to come in and fix the mutations are now not doing their job. When you have a lot of exposures, you end up getting a system that’s really out of balance where the immune system isn’t really able to respond that way, and you end up with more especially solid-state tumors.”
Johanssen said according to the Iowa Cancer Registry 2026 Cancer in Iowa report, they projected that 21,700 Iowans will be diagnosed with cancer, and 85 of those folks are projected to be here in Montgomery County.
“Our analysis showed that rural counties in Iowa are being hit harder with cancer. Of the 25 counties with the highest cancer rates, 80% of those are rural, while only 70% of Iowa counties overall are considered rural. Of particular concern here in Iowa is that we are seeing rising cancer rates in people under 50 years old. Iowa is also second nationally in this category, while rates nationally in people under 50 are flat. Cell mutations tend to increase as people get older, but the fact that this is happening in younger folks is a red flag,” Johanssen stated.
As they spoke to experts about the research they had done over time and they flagged the general categories, Johanssen said the first one that they looked at was pesticides.
“It’s an umbrella category that includes herbicides, insecticides, fungicides, and rodenticides. The pathways for pesticides to enter our bodies include through our skin, by eating or drinking the residues, and through breathing them in. People can be exposed to pesticides when they are using them, or part of manufacturing pesticides, and when they end up in the air or water soil and are trapped into our homes and end up in the dust that we all know piles up over time. Iowa is an outlier for use of three herbicides. In the most recent years, we’ve been by far the highest user of one of them, 80% more than the next highest state of Nebraska,” commented Johanssen. “There’s a list of cancers found in scientific research to be associated with the specific pesticides or pesticide mixtures. Colorectal, kidney, lung, prostate, and pancreatic cancers tare among those that are either increasing in Iowa or are higher here than the national average. Only ovarian cancer is not rising.”
Another category of concern for environmental pollution that has been associated with cancer is PFAS, manufactured chemicals that have special properties. They’ve been around since about the 1930s, in industrial and consumer products to resist stains and repel water, reduce friction, and withstand high temperatures. Teflon is probably the best-known product in this family for its use in cookware. They’re called forever chemicals because they do not break down in the environment because chemical bonds that form when these are created are some of the strongest that exist in the natural world. Because of their widespread use, people are exposed in many ways.
“There are thousands of different PFAS chemicals, and current testing does not capture all of these, so we’re likely underestimating how much PFAS is in our water and soil. Research on the links between cancer and PFAS is newer than some of the other areas we looked at, but there are strong links between PFAS exposure and kidney and testicular cancer, which are either rising or above the national average in Iowa, or both. There is evidence of links between PFAS and prostate cancer, ovarian cancer, and non-Hodgkin lymphoma as well.
Johanssen also shared details on nitrates and the possible link to increased cancer cases in Iowa. While nitrogen is found naturally in the environment, when it is transformed through chemical and biological processes with oxygen, it has the potential to turn into nitrate.
“Nitrate is found naturally in the soil. It’s also found in animal and human waste, and then also in synthetic fertilizers that are applied to our fields and our lawns. Only a fraction of the applied nitrogen fertilizer is taken up by plants, and the rest remains in the soil, and can also be transported into the air, or dissolved in the groundwater, which then flows to our surface water bodies. Another statistic related to nitrate that makes Iowa an outlier is the number of concentrated animal feeding operations in the state. Iowa has two and a half times more of these facilities than the next closest state, and a lot of these facilities actually are not permitted,” said Johanssen. “The livestock in these facilities are estimated to generate 110 billion pounds of manure annually, which is then spread on the ground as fertilizer, and that’s in addition to approximately 12 billion pounds of synthetic fertilizer. Some of these facilities have had issues with leaks, spills, and excess application of manure that contributes to nitrate contamination in our state. And that presents an enormous challenge for public water suppliers.”
According to Johanssen only 4% of the public water supplies in the state have the treatment capability to remove nitrate. That means that 80% of Iowans are receiving their drinking water from a community system that has to use other methods in order to meet the EPA limit of 10 milligrams per liter. In addition, Iowans who obtain their water from private wells have to be wary as well.
“The scientific research is showing that there’s connections to cancer even below that 10 milligrams per liter limit, down to five milligrams per liter. Some research even says three milligrams per liter. The cancer that has been studied the most in association to nitrates is colorectal cancer followed by ovarian and bladder cancer. Those are most strongly associated with nitrate. The other cancer sites, including kidney and renal, pelvis, thyroid, prostate, and childhood brain cancer have less research studies about them, but the ones that have been conducted show an association. It’s also very important to note when it comes to nitrate that it’s been studied longer than some of the other contaminants that we’re talking about,” Johanssen advised.
Johanssen closed out the session with discussion on Radon, which is a colorless, tasteless, and odorless gas that’s formed during the radioactive decay of radium, which is a naturally occurring metal in our environment.
“Radon gas then enters the buildings that we live in and the places we work through floors, ceilings, walls, ventilation ducts, any other cracks that allow that gas to seep into your home. Iowa is a hot spot for radon, and this is due to our natural geology and geography, not pollution. When we look at the cancer connections with radon, radon is the second leading cause of lung cancer in Iowa, and we know that lung cancer is the deadliest cancer in Iowa. When we remove smokers from that group, then radon is actually the leading cause of lung cancer in the state. When we look at a smoker’s risk, then Radon actually exacerbates their risk to get lung cancer if they are also exposed to it,” said Johanssen.
Other research also indicates that radon exposure at high levels is potentially linked to melanoma and stomach cancer as well. Johanssen said the key takeway is that Iowa is an outlier for exposure to environmental risk factors, and specifically for nitrate, pesticides, and radon.
“The research indicates that all of the most common cancers in Iowa have associations with environmental risk factors, and that those associated cancers are also rising in Iowa. In fact, 80% of the cancer types are associated with environmental pollution examined in the report, between pesticides, PFAS, radon, and nitrate. It’s clear that federal and state laws are not adequate to protect Iowans from carcinogens in the environment. We know that protective policies usually lay behind scientific research,” Johanssen stated. “Pesticide regulations are not adequately ensuring our safety. PFAS, we know, are entering the water and air with minimal controls. Nitrate is under-regulated in our drinking water sources, and we leave radon up to homeowners to monitor and mitigate. The bottom line is that there is significant evidence in both the associations with cancer and specific biological studies that tell us how cells are mutating in our body after being exposed to these chemicals. And those are contributing to our high cancer rates in Iowa.”
To help mitigate cancer risk, attendees were advised to participate in safe and informed individual pesticide use; transition to PFAS-free alternatives in household and personal care products; test for and mitigate nitrate in drinking water supplies; participate in private well testing programs through the county environmental health department or sanitarian, and test for and mitigate radon and other carcinogens inside the home.
Moving forward, solutions to the problem include sharing information with families, friends, and communities; sharing personal stories; having conversations with decision-makers, working with others to make sure voices are heard, and moving leaders to prioritize the health and lives of Iowans.
To get the full IEC report on cancer, maps, and graphics, visit iaenvironment.org/cancerproject.