Researchers studying a sharp rise in cancers in Iowa have honed in on a number of factors that have made the state America’s unlikely epicenter of new cases.
The state has the fastest growing rate of new cancers and the second highest cancer rate in the country for the second year in a row.
This trend left many Midwesterners and officials baffled because neighboring states, with similar demographics and agricultural practices, actually saw a decline in cancer rates.
But now officials are pointing to a unique environmental cause for the uptick.
It may be, at least in part, to do with a geographic anomaly – a radioactive gas that is leeching from the Earth thanks to geological changes that took place during the last ice age.
Each year, the Iowa Cancer Registry and University of Iowa release a report on how the state’s cancer cases line up with the rest of the country.
Pesticide use is one of the five factors likely contributing to the rise of cancer cases in Iowa, officials say.
Radon, a naturally occurring gas that gets released from weathered bed rock, is the number one cause of lung cancers in non smokers according to the Environmental Protection Agency (EPA).
Thousands of years ago, Iowa, and other parts of the Midwest, were covered by a gigantic glacier that began eroding that bedrock. Today, it’s worn down enough in specific areas that it can leach into soil and get into people’s homes.
Experts have now identified five potential factors why lung, breast, prostate and skin cancers are all rising at high rates across the Hawkeye state: obesity, radon exposure, tobacco habits, farming practices and alcohol use.
The interplay of these five factors is likely to blame for this cancer crisis, Mary Charlton, the director of Iowa Cancer Registry and professor in the University of Iowa College of Public Health Department of Epidemiology told the Telegraph Herald.
‘The unfortunate, unsatisfying answer I have for everybody is, it’s not one thing,’ Dr Charlton said. ‘It can’t be. We’re high in so many different types of cancer, and they all have different patterns, different geography patterns, different populations.’
Two in five Iowa residents will be diagnosed with cancer, according to the 2024 Cancer in Iowa report. That’s roughly 21,000 new cases, of which, 6,100 people are projected to die.
The state currently outpaces the national average for number of new cancer diagnosis – with roughly 480 new cases per 100,000 people, compared to the national average of 442 per 100,000.
In recent years, people have become clued in to how environmental factors, like pesticide use, could increase cancer risk, especially in rural areas.
It’s likely, experts said, that pesticide and fertilizer use plays a role in the Iowa cancer cases. The state, after all, uses more farming chemicals than any other: piling on 237million pounds of weed killer and 11.6billlion pounds of fertilizer annually.
When these chemicals bleed into the water supply, they can build up in the human body, and have been linked to cancers of the immune system, brain, breast, bladder, liver bile duct and ovaries.
But other environmental factors, like radon, might be just as important, the Telegraph Herald reported.
Radon is a naturally occurring radioactive gas that is produced when rocks and soil are worn down.
When gigantic glaciers covered the entire Midwest during the last ice age, they began grating on the rocks and other surfaces that covered this large, flat region.
Those same rocks were worn down enough that they are now releasing small amounts of the gas into soil across the Midwest, particularly in Iowa.
From the soil, radon can get into your home, the Iowa department of Health and Human Services warned. It can sneak through tiny holes made for wiring, service pipes or cracks in a building’s foundation, where it builds up undetected, unless the space is equipped with radon testing kits.
When someone inhales high levels of radon gas, it damages the lining of their lungs, leading to mutations that may eventually turn into cancer, the National Cancer Institute reported.
About 70 percent of homes in Iowa are at risk for radon exposure, according to the EPA.
In non-smokers, radon is the number one cause of lung cancer, the EPA reports. Another factor that Iowan officials are taking note of is obesity.
Obesity has been linked to multiple types of cancer. In Iowa, an average obesity rate and other factors, like alcohol use and radon exposure, compound to raise the overall rates of cancer in the state.
One of the risk factors that officials think may be contributing to cancer cases in Iowa is the drinking habits of the average Iowan.
Roughly 37 percent of Iowan adults are obese. That’s on par with national averages – where 41.9 percent of adult Americans were obese in 2023, according to the Trust for America’s Health.
Obesity incidence might add on to Iowans’ overall risk – pushing them into the high rate category.
Obesity has been identified as a risk factor for liver, kidney, gastric, breast, throat, thyroid and ovarian cancer, amongst others, according to the National Cancer Institute.
‘Overweight and obesity represent a public health crisis and any cancer-prevention strategy must include effective weight-loss strategies,’ Dr Andrew Nish, an interventional radiologist and director of the John Stoddard Cancer Center in Iowa, said.
Most of the studies that have unearthed this link have been observational – meaning scientists cannot definitively prove that obesity causes cancer. But the link is strong in some kinds of the disease.
For example, severely obese people are seven more likely to develop endometrial cancer, which affects the uterus, than people with a standard BMI.
There are a number of theories for this.
One is that obesity sometimes causes the body to suffer frequent inflammation, the NCI reported. Constant inflammation can put the cells in your body under stress, leading to DNA damage, which can in turn lead to cancer.
Another theory is that fat tissue produces estrogen. Too much estrogen over a sustained period of time has been linked to a number of cancers, the NCI reported.
Officials also highlighted the need to stay away from well-known risk factors, like alcohol and tobacco.
Dr Charlton noted that though smoking habits have been on a downward trend in Iowa, the state has been slower to throw away their cigarettes than the rest of the country.
In 2021, 14 percent of Midwesterners reported smoking, compared to 11.5 percent of all Americans, the Telegraph Herald reported.
Drinkers are five times more likely to develop throat or mouth cancer than non drinkers, the 2024 Cancer in Iowa report said. liver, throat, colorectal, lip oral and breast cancers.
Roughly 22 percent of Iowans binge drink, compared to 17 percent of Americans across the country.
‘Compared to other states, more Iowans drink, and in greater amounts. This may be why Iowa has the 4th highest incidence of alcohol-related cancers in the U.S., and the highest rate in the Midwest,’ the 2024 Cancer in Iowa report said.
Considering these five factors may help explain why across different corners of the state, new kinds of cancers are rising, Mary Rose Corrigan, the public health director for the city of Dubuque in Iowa, told the Telegraph Herald.
‘There’s a lot of things that contribute to it together, and it boils down to lifestyle, access, our environment and policies that help people have healthy lifestyles,’ Ms Corrigan said.
