The Role of Environmental Risk Factors in Iowa's Increasing Cancer Rate

As a non-partisan organization, IEC is thrilled to witness across-the-aisle collaboration on efforts to address Iowa’s alarming cancer rates. Governor Kim Reynolds introduced a proposal to allocate $1 million towards cancer research, including associated genetic, behavioral, and environmental risk factors. Ottumwa Representative Hans Wilz introduced a bill targeting radon exposure in aging Iowa homes, seeking to curb the state’s increasing lung cancer rate. Additionally, IEC supports ongoing research designed to highlight, address, and mitigate alcohol-related cancer risks. It's clear there is momentum on this issue. 

Amidst this flurry to intervene on Iowa’s increasing cancer rate, these efforts miss one contributor that is routinely masked, forgiven, and unchallenged by policymakers – industrial agriculture. The nation’s agricultural lobby is more influential than big pharma or big oil, and its impact on Iowans’ public health is unparallelled. How can we expect legislators to genuinely tackle environmental cancer risk while bending to powerful agricultural interests? How can we hold the industries accountable when they’re ever-present in our legislative process? 

Existing Cancer Research, Publications, and Prevention 

Unfortunately, cancer is remarkably difficult to predict and pinpointing its cause is even harder. According to the 2024 Iowa Cancer Registry report, Cancer in Iowa, “There is no one cause for cancer; rather it is the complex interplay of different genetic, behavioral, environmental, and structural factors that alter the way cells function and produce cancer.” The report continues to discuss the rise of alcohol-related cancers throughout Iowa as a justification for high cancer rates. However, it does not explain the discrepancy between other states with higher alcohol consumption, nor does it explain the significant increase of cancer over the past 30 years, or other risk factors. Despite cancer’s evasive nature, trends in Iowa are undeniable. 

The Iowa Cancer Plan, published by the Iowa Cancer Consortium and endorsed by Governor Kim Reynolds, Iowa Department of Health and Human Services Director Kelly Garcia, and others, strategizes cancer reduction goals through 2027. The report chapters focus on health equity, cancer prevention, early detection, diagnosis, and survivorship. Of the eight priorities of cancer prevention, five tackle behavioral causes of cancer, and only three address environmental causes of cancer: 

Priority 1: Reduce exposure to tobacco and secondhand smoke.
Priority 2: Enhance opportunities for Iowans to access nutritious food and be physically active.
Priority 3: Decrease alcohol consumption.
Priority 4: Increase immunization rates for vaccines shown to reduce the risk of cancer and protect cancer patients from preventable diseases.
Priority 5: Prevent, diagnose, and treat hepatitis C virus (HCV).
Priority 6: Reduce exposure to environmental carcinogens.
Priority 7: Decrease exposure to radon.
Priority 8: Reduce exposure to ultraviolet (UV) radiation from the sun and indoor tanning devices. 

Environmental Causes of Cancer 

Many Iowans are aware of the behavioral causes of cancer, such as cigarette smoking, poor diet, and a lack of physical activity. However, trends in Iowa indicate that there are external factors at play. Environmental causes of cancer include exposure to toxins in the air, water, food, or workplace that compromise an individual’s health, commonly exemplified with the connection between prolonged sun exposure and skin cancers. In Iowa, environmental causes of cancer are largely researched in connection with the agricultural industry. This includes concentrations of animal feeding operations, fertilizer and pesticide use, and runoff into beaches and waterways that have all grown exponentially since the 1990s. 

Last year, IEC updated our report Nitrate in Drinking Water: A Public Health Concern for All Iowans, which examines the links between unnaturally elevated nitrate concentrations in drinking water and public health risks. Peer-reviewed scientific research demonstrates links between nitrate in drinking water and increased risk of birth defects, colorectal cancer, bladder cancer, and other types of cancer. Nitrate pollution in Iowa primarily comes from agricultural sources such as fertilizers used on crop fields, livestock manure, and soil tillage, but it can also come from urban and other rural sources such as fertilized lawns, leaking septic tanks, and wastewater treatment systems. 

Similarly, Iowa’s corn and soybean industries use fertilizers, pesticides, and herbicides each year on millions of acres to assure an abundant yield. Iowa farms use significantly more crop nutrients than other states, including the well-researched carcinogenic pesticide glyphosate. Prolonged exposure to pesticides can increase an individual’s risk of various cancers, including non-Hodgkin lymphoma, leukemia, breast cancer, and prostate cancer. 

https://www.frontiersin.org/journals/cancer-control-and-society/articles/10.3389/fcacs.2024.1368086/full

While runoff impacts our soil and water, industrial agricultural releases, antiquated coal plants, and exhaust emissions also have devastating impacts to surrounding air quality. In cities proximate to coal plants, like Council Bluffs, Sioux City, and Ottumwa, respiratory cancer risk spikes due to toxic air particulates. In 2021, ProPublica released a report and associated map tool about cancer rates in relation to air pollution. The report found that elevated industrial and agricultural air pollution can increase an individual's cancer risk, depending on the duration, acuteness, and proximity. In 2024, IEC complemented these findings in our Coal in Siouxland: MidAmerican Energy’s Legacy of Air Pollution and Health Impacts report, focusing on adverse risks in western Iowa. 

Next Steps 

Advancements to address Iowa’s cancer concerns should not avoid the causes that set Iowa apart. We must hold our legislators accountable to create and support policies that mitigate environmental causes of cancer. Better yet, we must publicly and loudly criticize polluters in their many forms: CAFOs emitting toxic odors near schools and neighborhoods, crop fields overusing fertilizers running into our rivers and streams, and heavy pesticide use exposure on farmhands, consumers, and livestock. Industrial polluters, like Iowa’s dirty coal plants, manufacturing facilities, and agricultural processing plants, should face scrutiny in their own right. 

IEC and our partners who work on water quality, air pollution, and land stewardship see it: Iowa’s cancer crisis is worsening fast. Progress will be made — and lives saved — only if we have the courage to acknowledge the minefield ahead of us. We’re continuing our work at the Capitol to advocate for Iowans exposed to environmental causes of cancer and center conversations around environmental risk factors. 

If you have thoughts or questions, contact Sarah Howe at howe@iaenvironment.org for more information.