Tobacco tax, pesticide monitoring could help address Iowa’s high cancer rates, researchers say

Researchers told Iowa House lawmakers Wednesday that legislation raising taxes on tobacco and implementing more pesticide monitoring requirements could help lower the state’s high cancer rates and provide more information on its causes.

The House Health and Human Services and Environmental Protection committees held a joint meeting Wednesday where they heard from speakers with the University of Iowa’s College of Public Health about key factors driving Iowa’s cancer rates.

These UI researchers and staff presented preliminary information gathered in a yearlong research project conducted through a UI partnership with the Iowa Department of Health and Human Services. Lawmakers had approved $1 million in funding last year for the project, seeking to identify the factors leading to Iowa’s ranking as having the second-highest rate of new cancer cases in the country, and as one of only two states with a rising rate of new cancers in 2025.

The preliminary data, first presented in a news conference with Gov. Kim Reynolds in February, identified that Iowa has higher rates of prostate, breast, lung cancer and melanoma, when compared to national trends. The initial study released did not examine environmental and genetic factors, but examined demographic and behavioral factors related to cancer incidences.

When compared to other states with similar rates of certain risk factors, like binge drinking, obesity, insurance rates as well as factors like income and college education in the Midwest, Iowa had similar cancer trends in many cancers, but had significantly higher instances of lung cancer and mortality rates when compared to both the national rate and other Midwest states.

The UI staff reiterated to lawmakers many of the points they made in their initial presentation of the data — there is likely not one single factor behind Iowa’s growing cancer rates. Researchers also said that the factors that have caused Iowa to begin having a statistically significant higher cancer rate than the national average beginning in 2013 and 2014, may have come from issues in Iowa a decade or more prior.

Jacob Oleson, a professor of biostatistics at the University of Iowa College of Public Health, said the data collected for these initial results came from established national and state sources like the Iowa Cancer Registry, Centers for Disease Control and Prevention and the U.S. Census to provide a baseline on both known risk factors contributing to cancer in Iowa, as well as identifying which types of cancer and which areas of the state deviated from expected cancer instances.

“We wanted to start as soon as we can, and not spend time collecting data,” Oleson said. “We wanted to get whatever results we could as fast as we could. In order to do that, we had to use existing data. So we turned to what nationally we could look at immediately, and what statewide we could look at immediately, and what states that we could look at — comparing Iowa to other states — immediately within this year timeframe. So that’s broadly the data that we have. And then as we move forward, we can start looking at more specific information, such as the environmental data that we’re working on collecting.”

But as the researchers enter their next stage of analysis, they said getting the data necessary to assess environmental and genetic factors that may be contributing to Iowa cancer rates is expected to be more difficult.

Democrats and environmental protection advocates have pointed to high nitrate levels in Iowa waterways as a potential factor contributing to the state’s cancer rates. When asked by House lawmakers about the potential impacts of nitrate, Dr. Mary Charlton, UI professor of epidemiology and the Iowa Cancer Registry director, said nitrate levels and water quality will be assessed within the next phase of the project, but said there are many factors making it difficult to properly assess the impact.

“I don’t know how many of you in this room have ever only drank from one water source in your life,” Charlton said. “Probably not very many. We don’t have longitudinal records of where you have all lived and all the water sources you drink from, and the nitrate levels in those water sources. And the nitrates you may be ingesting now, don’t have anything to do with the cancer rates now. That will take decades to develop. So that is the trick with those but we’re going to do the best we can with the available data.”

In Iowa cities, Charlton said there is typically “pretty good monitoring data on nitrate levels” that will be used in research. However, she said, another factor that could present significant problems is private wells. Charlton said there are an estimated 300,000 people who get their water from private wells in Iowa, which are not regulated.

“We have a lot of people that are not checking their wells,” Charlton said. “Those are not regulated. There’s no way to know what’s in there unless you check them. So I think that’s a huge area of opportunity for people concerned about that.”

Another factor that Charlton said will be difficult for researchers to gather meaningful data on is how exposure to pesticides may contribute to Iowa cancer rates. She pointed to California’s pesticide reporting system as an example of how the state could collect data on where and what pesticides are applied, which could be compared to cancer data.

“What we don’t know in Iowa is, what is the exposure to non-farmers or non-occupational people in terms of agriculture exposure?” Charlton said. “We don’t even know if and how they’re exposed to pesticides. … We talk a lot about water quality, and we should. We don’t talk a lot about air quality. What’s in the air relative to people who may live near farms. It may not increase their risk, but it might, and we don’t know. We don’t have those types of surveillance systems or monitoring systems, we don’t even have anything to plug into our models.”

Charlton said pesticide exposure may not play a factor in rising cancer rates, but that because this information isn’t collected in a way that allows researchers to examine whether proximity to lands where pesticides are used has any correlation to the state’s cancer rates, there is no way to tell.

“There are systems that are already laid out there in the country, like in California, that we could do, and I would argue that we should do, in Iowa,” she said. “We use a lot of pesticides. We should know. Again, it might turn out that it’s not a very big exposure, that people living near farms aren’t exposed very much to those, but it may turn out that they are. It may turn out that they’re inhaling it, it may turn out that it’s in the dust in their homes, and their small children are licking it off of toys — we don’t know.”

She advocated for implementing a pesticide monitoring system, as well as investing in state entities like the Iowa Department of Natural Resources, State Hygienic Laboratory and UI Occupational Environmental health professionals, that would be able to provide helpful data in cancer research.

Rep. Brett Barker, R-Nevada, asked the researchers to comment on proposals to raise tobacco taxes in the state. The governor put forward a measure to increase taxes on cigarettes and tobacco products and to institute a new tax on consumable hemp and vape products in her “Make America Health Again” bill. But that provision was taken out of the legislation as it advanced through the House.

Barker introduced a separate proposal, House File 2406, to raise taxes on cigarettes and other nicotine products, like e-cigarettes and pouches, which has not been scheduled for a subcommittee meeting.

Barker, a pharmacist, said he believes he “raised some eyebrows” when he put the measure forward, but said his experience as a health care provider led him to consider the measure. Higher taxes have been shown to lower tobacco usage in some places — a significant concern as the research highlighted the state’s high lung cancer instances and mortality rates, he said.

Charlton said when Iowa raised the state tobacco tax in 2007, there was a “significant decrease” in smoking rates in Iowa. She said though this will not completely eliminate lung cancer risks, it would contribute to healthier outcomes in Iowa.

“Everybody knows people who smoked their entire lives and never got lung cancer, and people who never smoked and still got lung cancer, that’s the complicated part and the maddening part of it,” Charlton said. “But raising the tobacco tax is the single most impactful public health intervention, period, across the board, that has been shown to save lives, reduce cancer, reduce cancer deaths.”

In addition to raising the tobacco tax, researchers said measures to provide resources for individuals wanting to stop smoking, as well as for people wanting to test their homes for radon and mitigate radon if found would help lower lung cancer rates.

The cancer research project is ongoing. The team members said they plan to have modeling and mapping analysis for lung, melanoma, colorectal and HPV-associated cancers completed by July 1, 2026. They plan to prepare a report for the governor and lawmakers with findings that include environmental and genetic data, as well as recommendations for evidence-based cancer prevention programs in the second year of the project.