Iowa's Cancer Report Didn't Ask the Most Important Question. For Polk County, That Matters.

Iowa's annual cancer report dropped last week. The headline that spread across news feeds was reassuring: Iowa farmers have 13% fewer cancers than the general population.

What the report never examined is what those farmers — and what Polk County residents, and what rural Iowans across the state — are actually drinking.

The Number That Should Have Led the Report

Iowa's young adult cancer rate is the second highest in the nation. It is increasing. An estimated 21,700 Iowans will be diagnosed with cancer in 2026. The report acknowledges all of this — and then pivots to farmer cancer rates without ever connecting those two facts to Iowa's water.

About 230,000 Iowans rely on private wells. Nearly three-fourths of Iowa's contaminated private wells are in rural counties. No state or federal agency requires testing or treatment of those wells. Iowa recommends annual testing. It does not require it.

Research has associated long-term nitrate exposure — at levels below the federal legal limit — with increased risk of colorectal, bladder, ovarian, and breast cancer. A 2025 study found elevated cancer risk in Iowa women from nitrate concentrations in public water systems that are currently legal under federal standards.

This Is a Polk County Issue

I live in Des Moines, Polk County. This is not an abstract rural problem from across the state.

Des Moines Water Works draws from the Raccoon River — one of the most nitrate-contaminated waterways in Iowa. In 2015 Des Moines Water Works sued three upstream counties over drainage tile systems pumping nitrate directly into the watershed. The lawsuit was dismissed. The nitrate is still there.

Research has identified South-Central Iowa including Polk County as an area where nitrate contamination affects more than 28% of groundwater wells. Residents in Polk County and surrounding counties — Warren, Madison, Jasper, Marion — who rely on private wells are drinking unregulated, largely untested water in one of the most agriculturally intensive regions in the country.

Iowa's average nitrate contamination in public water systems jumped 29% between 2003 and 2017. It is not getting better.

What Iowa's Leaders Should Be Doing

The Iowa Environmental Council has outlined the solutions for years. Mandatory private well testing. State funding to help rural residents address contamination. Stronger nitrate limits that reflect current science rather than a 1962 standard. Agricultural nutrient management policies with real accountability.

None of this is moving through the Iowa legislature this session.

Iowa released a cancer report that studied farmers without asking what they drink. It found a population with lower smoking rates and a healthy worker advantage has fewer cancers overall — and called that reassuring news. Meanwhile Iowa's young adults have the second highest cancer rate in the nation and the water flowing into Polk County from upstream farm fields keeps getting worse.

Iowans deserve harder questions than the ones this report was willing to ask.

Read the full analysis on Medium: Iowa's Groundwater Is Contaminated With Cancer-Causing Nitrates. The State's New Cancer Report Never Once Mentions It.