GEOFF BENNETT: About a fifth of America's total petrochemical production is concentrated on a stretch of land along the Mississippi River in Southeastern Louisiana.

Those facilities provide many of the essentials of modern life, plastics, fertilizer, and even medical equipment.

But that production also comes with serious risks.

The area has also long been known as Cancer Alley because of the high rates of cancer among people who live near those plants.

As William Brangham reports, a new study now documents how those risks may fall on the next generation as well.

TEESHA, Mother: All right.

WILLIAM BRANGHAM: Not long ago, Teesha couldn't imagine making memories like this with her son, Cairo (ph).

TEESHA: You sharing with mommy?

WILLIAM BRANGHAM: He was born prematurely, almost two months early, weighing just four pounds.

He had to live in this incubator, had a slow heart rate, and sometimes stopped breathing entirely.

TEESHA: My first time seeing him after birth, I was holding him, and he looked so peaceful.

And I was like, oh, my God, he's so peaceful.

And I took a picture.

And, seconds later, his alarms went off.

He had stopped breathing.

And -- and, of course, just me being new to the experience, it was very overwhelming.

There we go.

WILLIAM BRANGHAM: Teesha, who asked we not use her last name for privacy reasons, has lived in Louisiana's St. John the Baptist Parish most of her life.

The community sits within an 85-mile stretch of land that's home to some 200 fossil fuel and petrochemical operations.

TEESHA: Growing up, we knew nothing about how those things were affecting us.

You know, you just had asthma, you just had eczema.

You just had all of these other different issues.

Your grandmother had cancer,a lot of people, women I know with fertility issues, a lot of women I know trying to get pregnant and can't, or experiencing a lot of miscarriages or early births.

And we just thought that that was normal life.

WILLIAM BRANGHAM: Last month, researchers at Tulane University found that, in Louisiana's most polluted areas, pregnant women had a 25 percent higher risk of low birth weights and a 36 percent higher risk of premature births.

Prematurity is the leading cause of death among infants in the U.S. Black and low-income women in those areas face the highest risks.

KIMBERLY TERRELL, Tulane Environmental Law Clinic: It's a wake-up call in terms of how we think about the consequences of industrial pollution.

And what you emit today affects the health of somebody who's going to be born in six months or nine months, right?

It's not decades from now.

WILLIAM BRANGHAM: Kimberly Terrell is a staff scientist at Tulane's Environmental Law Clinic and was lead author of the study.

KIMBERLY TERRELL: What was really surprising was the proportion of adverse birth outcomes that could be attributed to pollution exposure in Louisiana.

So, our study suggests that a third of the cases of low birth weight and about half the cases of preterm birth in the state can be linked to pollution exposure.

STATE SEN. EDDIE LAMBERT (R-LA): The Mississippi River is full of petrochemical plants, as well as grain elevators, because they are truly the gateway to the world.

WILLIAM BRANGHAM: Louisiana Republican state Senator Eddie Lambert chairs the Environmental Quality Committee, which oversees the agency that regulates the chemical industry.

I'm sure your committee has seen the number of studies that have linked living in these areas to disproportionately high negative health outcomes.

You don't accept that as a premise?

STATE SEN. EDDIE LAMBERT: I don't accept that as a complete truism.

I mean, there may be some correlations.

I mean, I'm going to tell you, let's start looking vaccines.

We have had an explosion of vaccines in the last 20, 30 years.

Now you have autism.

Is there a connection there?

I don't know.

There's a lot of people who think they are.

WILLIAM BRANGHAM: There's a lot of people who think there are, but there's no good evidence that they are connected.

STATE SEN. EDDIE LAMBERT: And that may be the same thing with some of the situations with the chemical plants.

There's circumstantial evidence that's there.

But you know what?

Let's really dig down and see, what is the -- what is there?

WILLIAM BRANGHAM: He says there are other reasons women in these areas may be experiencing poor birth outcomes.

STATE SEN. EDDIE LAMBERT: Is it economically depressed, their health?

What kind of prenatal care are they doing?

I mean, there's all kind of factors.

WILLIAM BRANGHAM: But Terrell argues, those factors were accounted for in her study, and they aren't exclusive.

KIMBERLY TERRELL: They are compounding.

It doesn't make sense to say, well, we're just going to ignore pollution and focus on poverty or health care access.

If we know pollution is a risk factor -- and we do.

We absolutely know that pollution is linked to low birth weight and preterm birth across the board.

Why aren't we addressing that?

WILLIAM BRANGHAM: You think, on balance, right now, you guys are hitting that correct balance of economic development versus protecting people's health?

STATE SEN. EDDIE LAMBERT: We could probably be doing a little bit better on both.

I would like to see no pollution.

That's a perfect scenario.

Now, how much of a negative impact there is?

I don't know.

But I know they also bring a lot of things to us that we could not exist without them.

Would it not be for the chemical industries, especially fertilizer, you could not support the world's population.

WILLIAM BRANGHAM: A recent report from Human Rights Watch found that, for decades, the Louisiana department of environmental quality, or LDEQ, has repeatedly failed to enforce the minimum standard set by the federal government and to protect the environment and human health.

And Terrell says that agency still hasn't acknowledged the racial disparities in who gets exposed to pollution.

From 2019 to 2021, the department allowed industrial emissions of pollution that were seven to 21 times higher in mostly Black communities compared to mostly white ones.

In an e-mail to the "NewsHour," the department declined to comment.

KIMBERLY TERRELL: I think the key is that the DEQ needs to take an unbiased approach to environmental justice analysis in its permitting decisions.

And what that means is, when a facility wants to build a new plant in a community of color, DEQ needs to say, OK, what's the existing burden of pollution here?

And is this community overburdened?

WILLIAM BRANGHAM: Two years ago, the Environmental Protection Agency opened up a civil rights investigation looking at whether state regulators here in Louisiana were allowing oil and gas and petrochemical companies to build and pollute in a way that disproportionately harms Black communities.

In response, Louisiana's then-attorney general and now governor, Jeff Landry, sued the EPA, and the agency dropped the investigation.

The EPA declined to comment, citing pending litigation.

ASHLEY GAIGNARD, Rural Roots Louisiana: We're going to focus on mitigation with climate change.

WILLIAM BRANGHAM: In Ascension Parish, another community with concentrated petrochemical plants, Ashley Gaignard is counting on a younger generation to enact change.

She founded the organization Rural Roots Louisiana to teach kids about environmental issues.

ASHLEY GAIGNARD: That creates another generation of awareness.

It preserves our land.

It sustains what we have, because, if we don't start preserving it, the industry is going to buy out every piece of clean property that they can.

WILLIAM BRANGHAM: All three of Gaignard's children were born premature and with low birth weights.

She says, at the time, she didn't connect her baby's poor health with the air she breathed when she was pregnant.

ASHLEY GAIGNARD: My son born with an undeveloped lung, and he's had really horrible asthma all his life.

And to have a kid get told he can't take recess anymore, when you learn you got formaldehyde in the air and methyl ethylene in the air and benzene in the air, and all of those chemicals have effects on your respiratory system, you get angry.

WILLIAM BRANGHAM: Back in St. John the Baptist Parish, Teesha says, even now, she worries about how the air could be harming her son.

If you could, would you move far away from here?

Is that something you have thought about?

TEESHA: It's something that I thought about, but I love here.

I don't want to be anywhere else.

I want to be home, and I want my baby to know home and love home the way that I do.

So what do you do when you need to be home, and home is, unfortunately, where the problem is?

WILLIAM BRANGHAM: For the "PBS NewsHour," I'm William Brangham in Southeastern Louisiana.