AMNA NAWAZ: For years, national conversations about cancer often focused on the so-called Cancer Alley in the Deep South or Appalachian states with high smoking rates.

But, recently, a different state has grabbed headlines.

Iowa.

It now has the second highest cancer incidence in the country, and is one of only three states where rates are rising.

Special correspondent Fred de Sam Lazaro went to Iowa and has this report on the search for answers.

FRED DE SAM LAZARO: For 35-year-old Becca Mataloni, it started in 2019 with a crackling noise every time she inhaled.

BECCA MATALONI, Iowa Resident: Kind of like dial-up Internet, is how I always describe what it sounded like.

FRED DE SAM LAZARO: In 2022, she developed pneumonia, in 2024, another bout of pneumonia.

Mataloni, who lives in the Des Moines area, had multiple scans and met with a pulmonologist, who delivered the diagnosis, a cancerous tumor on her lung.

BECCA MATALONI: It's really devastating to get a cancer diagnosis in your 30s.

And even though my pulmonologist told me that I was going to be OK, it sucks, and hearing I'm going to lose two-thirds of my lung.

Like, one of the first questions I asked was, am I still going to be able to do the things I love?

FRED DE SAM LAZARO: In rural Northern Iowa, Shelley Phelps lost her sister to breast cancer in 2015.

Two years later, her husband, Michael, was diagnosed with stage four colon cancer.

SHELLEY PHELPS, Iowa Resident: You think, how can I go through this again?

And how can my kids go through this again?

FRED DE SAM LAZARO: They had to drive at least an hour any time Michael needed treatment.

In 2020, he died at the age of 50.

SHELLEY PHELPS: I have always said that, if it wasn't for my faith, I would not have gotten through this, because you're always waiting for that next shoe to fall.

Who's going to be diagnosed next?

FRED DE SAM LAZARO: The stories represent a grim reality for Iowa, which was following national cancer trends until about 2013, when rates began to rise, driven by prostate, breast and lung cancer, as well as melanoma.

Now, for the third year in a row, it's got the second highest cancer incidence in the country.

Its rate among young people is also near the top.

As Iowa's high cancer rates have persisted in recent years, there's been growing public concern, with key unanswered questions.

What's to blame for them and what are state officials doing about it?

MARY CHARLTON, Iowa Cancer Registry: As much as we would love to reduce it down to one thing and figure this out and change Iowa's rates, we would do that.

But that's not how cancer works.

FRED DE SAM LAZARO: Mary Charlton leads the Iowa Cancer Registry, which has tracked the state's cancer data for over 50 years.

Charlton and her staff have been traveling Iowa's 99 counties, meeting with residents.

MARY CHARLTON: A lot of people that come to the meetings have had cancer, had a loved one diagnosed with cancer, and they want to know why.

That's a really maddening thing about cancer too is, people can be exposed to the same things and their immune system might process them differently.

It's not an excuse to not try to figure out what's causing the cancer and do something about it, but it kind of explains why it's kind of a slow slog to figure out what's causing our rates to be higher than the rest of the country.

FRED DE SAM LAZARO: Charlton does talk about some potential culprits and solutions.

Iowa has among the nation's worst binge-drinking rates.

It hasn't raised its cigarette tax, proven to reduce smoking, in almost 20 years.

And the entire state is labeled high risk for radon, a radioactive gas found naturally in the earth that can seep into homes and cause lung cancer.

Adam Shriver is the director of wellness and nutrition policy at The Harkin Institute of Drake University in Des Moines.

ADAM SHRIVER, The Harkin Institute, Drake University: We felt like a lot of the discussions in the state had been focusing on behavioral factors and genetic factors, but there was sort of this big elephant in the room in Iowa, which is the fact that we are one of the most intensively farmed states in the country.

FRED DE SAM LAZARO: Agriculture accounts for over 80 percent of Iowa's total land.

The state produces more corn, eggs, and pork than anywhere else in the country.

In March, Shriver and a team of researchers released a report that showed links between Iowa's most common cancers and certain environmental risk factors like pesticide use and nitrate run-off from fertilizers.

Dan Voss is a fifth-generation corn and soybean farmer near Cedar Rapids.

In 2012, Voss' wife, Susan, was having a routine checkup when doctors found a mass in her abdomen.

It was liver cancer.

She underwent treatment and surgery and is now cancer-free.

In 2024, after experiencing some issues with his hands, Dan was diagnosed with non-Hodgkin's lymphoma.

He's currently undergoing maintenance chemotherapy.

Have you wrestled with the mystery of what -- you know, what got you here?

DAN VOSS, Iowa Farmer: Well in my case, could it be ag?

Well, I think there's a chance.

Can I say it is with 100 percent certainty?

No.

I think the state needs to have a good honest discussion about where we're at, what we can do.

There are some things we can do on the ag side that would probably help.

FRED DE SAM LAZARO: For years, Voss has used farming techniques that reduce the amount of nitrates in the water.

DAN VOSS: Just because you talk about it, that's not an indictment of agriculture.

ADAM SHRIVER: I would definitely argue that, right now, public health is not part of the equation when we're deciding on agricultural policy.

And it seems like it really should be.

FRED DE SAM LAZARO: You are convinced that the fertilizers that you use today and the insecticides are safe if applied as directed on the label?

STEVE KUIPER, Vice President, Iowa Corn Growers Association: Yes.

FRED DE SAM LAZARO: Steve Kuiper is vice president of the Iowa Corn Growers Association, a major industry group in the state.

STEVE KUIPER: Too many people are poking farmers in the chest and saying, you're polluting, you're polluting, you're polluting.

Farmers are more than willing to make changes and make adjustments to their operations, but they need some data to support that.

A lot of products have gone -- had years and years of testing before they ever went to market.

So then, all of a sudden, everybody's like, well, this has got to be the problem.

FRED DE SAM LAZARO: Iowa Corn has joined a coalition mostly made up of health organizations working to solve the state's cancer crisis.

DR.

DANIEL KOLLMORGEN, Mahaska Health: When a patient comes to see me with a new cancer, they typically aren't asking about, why are the cancer rates in Iowa so high?

They're asking about, what do I do for mine.

It does pick up stuff.

FRED DE SAM LAZARO: Daniel Kollmorgen is the medical director of oncology at Mahaska Health in Oskaloosa, a city of about 12,000 about an hour east of Des Moines.

DR.

DANIEL KOLLMORGEN: Oftentimes, in a rural location, there can be delay from onset of symptoms to accessibility of diagnosis, getting a biopsy, getting scheduled.

I try to move them off the bubble of not knowing what's going on, I have a cancer and I'm going crazy, but they don't know what comes next, and to reassure them that there is treatment, that there's a pathway forward.

FRED DE SAM LAZARO: Although the incidence of cancer in Iowa is high, mortality rates so far are in line with the rest of the country.

It's one reason Kollmorgen says he'd like to see better cancer screening in rural areas, but also tighter regulation of farm chemicals and more water quality monitoring.

ZACH LAHN (R), Iowa Gubernatorial Candidate: It's about stopping the cancer crisis that is plaguing our state.

FRED DE SAM LAZARO: In November, Iowans will vote for a governor, U.S.

senator and agriculture secretary.

Tackling the state's cancer problem has already come up repeatedly on the campaign trail.

And while many residents want more action from lawmakers, people like Shelley Phelps are filling in the gaps where they can.

She's part of a foundation that's helped over 700 people in her county dealing with cancer.

More requests come every week.

For the "PBS News Hour," I'm Fred de Sam Lazaro in Iowa.