Iowa’s cancer rate has recently received a lot of attention. As the report from the Iowa Environmental Council and The Harkin Institute (2026) states, Iowa is now an outlier for cancer in America. Iowa is now one of only two states in the USA with an increasing rate of cancer. We also have the second-highest rate of cancers diagnosed each year. The Interim Findings Report of the Key Drivers of Cancer in Iowa Project (University of Iowa College of Public Health, 2026) concluded that demographic and behavioral factors cannot account for the increased cancer rates in several Iowa counties, including Woodbury and Cherokee. As a consequence, many Iowans are asking how environmental risk factors for cancer could effect our rates of developing cancer. For some Iowans, it is past time that these risk factors must be considered, as they contribute to the development of other diseases in addition to cancer in humans and to the degradation of our ecosystems.
Consider our air quality, for example. Step outside in Sioux City, and you will find a large number of industrial giants surrounding you, releasing clouds of particles that include PM 2.5. PM 2.5 is a carcinogenic form of air pollution in which particles have a diameter of 2.5 micrometers or less (IEC, 2026). How this pollution effects us is not surprising. In Iowa, Woodbury County has the highest asthma rates in adults older than 18, and people ages 5-65 years old “had higher average rates for asthma-related emergency department visits when compared to statewide rates” (Smith, 2024).
Asthma is not where the health concerns stop, however. COPD (chronic obstructive pulmonary disorder) is another common disease in the Siouxland area, which is unusual due to our urban setting and population size. Woodbury County has higher rates of COPD than larger counties such as Polk, Linn, and Scott (Smith, 2024). It is important to note that this pollution does not effect everyone equally. Native Americans make up only 1.6% of the population just across the Missouri River in Nebraska, but they accounted for 13.6% of COPD cases between 2016 and 2020.
Water pollution also negatively effects Iowans. Most of our water issues stem from agricultural and urban runoff, as well as industrial discharges. Approximately 85% of Iowa’s land is used for agriculture, and Iowa has one of the highest pesticide use rates in the nation (IEC, 2026). Pesticides can attach to soil particles that blow up into the air, contributing to air pollution. However, the primary means of exposure to pesticides is likely after they have washed off the fields and into the streams and rivers that supply our drinking water. Studies have consistently found these chemicals and their breakdown materials in surface waters, public and private wells, and groundwaters in Iowa (IEC, 2026). Pesticides can harm our reproductive and endocrine systems, be toxic to our nervous system, and cause cancers (IEC, 2026).
Nitrate concentrations in the waters of Iowa often exceed the EPA’s recommended safe levels (10mg/L) for a portion of every year. Studies show that continued exposure to nitrate levels as low as one-quarter of the EPA limit is correlated with increased risks of developing several types of cancer (IEC, 2026). On June 18, 2026, the water quality gauge in the Floyd River, just north of Sioux City, in James, showed that the nitrate + nitrite level was 15.8 mg/L (IWQIS), more than 50% higher than the safe limit. Earlier in June, the nitrate + nitrite level exceeded 17 mg/L, reaching 18 mg/L. High levels of nitrogen in our waters are associated with the application of fertilizers and with waste from animal feeding operations.
PFAS (per- and polyfluoroalkyl substances) chemicals are also found in Iowa’s waters and can attach to PM 2.5 air particles. PFAS are a suite of chemicals often called “forever chemicals” because they do not break down readily in the environment. While they can be found in household products, they are also used in industry, including in pesticide manufacturing (IEC, 2026). One study reported that PFAS were found in 94% of surface waters in Iowa and in 30% of groundwater samples. PFAS exposure has been linked to an increased risk of developing certain types of cancer, such as kidney and testicular cancer (IEC, 2026).
While these data on air and water pollution in Iowa are shocking, all is not lost. We can protect our families and neighbors by pushing our leaders to prioritize regulations that reduce these pollutants in our state. We need more air monitors in our communities, and we need to hold big polluters accountable. Currently, Iowa has inadequate air monitoring standards (IEC, 2025). With help from the Iowa Environmental Council, several residents have placed PurpleAir Monitors around Sioux City, but we need more monitors and stronger air-monitoring standards. Similarly, we need additional water quality monitoring stations and regulations to reduce water pollution. All Iowans deserve clean air and water. We need to do better, and we deserve a healthy environment to live in.
Sources:
Iowa Environmental Council. (June 13, 2025). Air Quality Monitoring Data Show Additional Steps Needed to Protect Public Health. https://www.iaenvironment.org/newsroom/council-news/air-quality-monitoring-data-show-additional-steps-needed-to-protect-public-health?shem=rimspwouohc,
Iowa Environmental Council and the Harkin Institute for Public Policy and Citizen Engagement. (2026). Environmental Risk Factors and Iowa’s Cancer Crisis: A 2026 Report. https://www.iaenvironment.org/webres/File/Environmental%20Risk%20Factors%20and%20Iowa’s%20Cancer%20Crisis%20-%20Report(1).pdf
Iowa Water Quality Information System. https://iwqis.iowawis.org/app/
Smith, C. (2024, May). Coal in Siouxland: MidAmerican Energy’s Legacy of Air Pollution and Health Impacts. Iowa Environmental Council. https://www.iaenvironment.org/webres/File/Coal%20in%20Siouxland%20-%20Final%20Report.pdf
University of Iowa College of Public Health. (2026, March 11). Key Drivers of Cancer in Iowa: Project Progress Update. https://www.legis.iowa.gov/docs/publications/HMD/1602513.pdf
By David Hoferer
