KJS 10-26

Iowa is the country’s biggest corn and hog state. A few years ago, no candidate there would have mentioned farm pollution and cancer in the same breath. This year five of the six House, Senate and gubernatorial candidates who appeared at the State Fair discussed the state’s high cancer rate.

The numbers themselves are not in dispute. Iowa’s rate began rising in 2014 after more than a decade of decline, and it has been the second highest in the nation, behind Kentucky, since 2023. It is one of only three states where the rate is still climbing. Mortality so far is in line with the national rate.

Here is what every campaign shop needs to say out loud: nobody has established what is driving the increase. State and University of Iowa researchers found that 76% of Iowa’s higher rates for five common cancers can be attributed to demographic and behavioral risk factors. Researchers have not established a single environmental cause. A second phase of the state study will examine environmental factors.

Anyone who says glyphosate or nitrates did this is ahead of the evidence. So is anyone who says the water is irrelevant.

Voters are not waiting for the epidemiology. Their concern is driven partly by worries that worsening nitrate and chemical pollution in the water may be behind the spike. The legislative record made those worries personal.

In 2025 the Iowa Senate passed Senate File 394 by 26 to 21, a Bayer-backed bill that would make an EPA label sufficient to satisfy any duty to warn. The practical effect was to end the failure-to-warn lawsuits cancer plaintiffs depend on. Opponents who rallied in the Capitol rotunda called it the “Cancer Gag Act.” It was part of a push in about a dozen states. The Iowa House let it die. In June the Supreme Court did nationally what the Iowa House would not do.

That history now shapes the race. Democrat Josh Turek has tied water quality to the cancer crisis and proposed nitrate-removal infrastructure and incentives for farmers to plant land buffers and cover crops. His Republican opponent, Ashley Hinson, has called the rising rates unacceptable. For the first time, addressing the environmental causes of cancer appears in the campaign platforms of both parties. One Republican candidate is running on cleaning the water and regulating chemicals, which is unusual in his party.

Lessons for political officers

First, argue accountability, not causation. Causation will take years and will stay contested. Accountability can be settled now. Who is testing the wells? Who is disclosing what they know? Who voted to limit people’s ability to sue? Those questions have answers, and voters can act on them.

Second, farmers are the most exposed constituency, not the opposition. The voter with cancer in the family is often the one working the land. A message that casts agriculture as the villain loses that voter. A message that treats cancer concern as farmer-bashing loses the same voter from the other side. The candidates doing best are talking about water, prevention and screening, not blame.

Third, liability votes are now permanent exhibits. A vote to shield a chemical manufacturer can be reduced to a single sentence in a mail piece. It will outlast this cycle, and it will outlast the science.

Underneath all of this is something I think about for a living. The decisive variable here is not a carcinogen. It is whether voters believe the institutions explaining the numbers to them. The state’s lifestyle explanation may well turn out to be mostly right. But it will not land with people who watched those same institutions fight over who gets to warn them. The candidates who understand that distrust of the explanation can outweigh the explanation will be the ones still standing after this issue matures.

Polls close Tuesday. The cancer rate will still be there on Wednesday.

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