Links between environmental exposures and maternal health outcomes remain underexplored, despite recent efforts to catch up.
By Dan Ross, Capital & Main
This story is produced by the award-winning journalism nonprofit Capital & Main and co-published here with permission.
Deborah Bell-Holt lives near a decades-old drilling site in South L.A., where oil sucked to the surface comes laced with dangerous pollutants like benzene, formaldehyde, methane and toluene. What comes up must go somewhere, and Bell-Holt is sick at the prospect of how much toxic pollution ends up inside the bodies of her family and friends.
“There are moments where I’m so furious,” says Bell-Holt, 69, who has fostered six children. All of them, like her, suffer chronic asthma, a problem linked to the proximity of oil drilling. Some children have terrible skin problems. Her husband has been battling leukemia for several years. As if that wasn’t enough, Bell-Holt now worries about a new generation. “My oldest child is 26, and she has a child that’s 3 years old, and they’re both asthmatic, and they both live here.”
Pregnant mothers living close to oil drilling sites, for example, are at greater risk of giving birth to an underweight baby, a leading cause of infant mortality. More than 2.1 million Californians live within 2,500 feet of an operational oil well.
Bell-Holt said her granddaughter’s asthma has worsened. “She’ll tell you, ‘My chest hurts. I can’t breathe.’ And my daughter takes her immediately off to the children’s hospital. And then she’ll get a breathing treatment, antibiotics and steroids. But the steroids are not good for her to have. She’s a baby — what does she need to be on steroids for to breathe?”
A growing body of research links prolonged exposure to dangerous pollutants and toxic chemicals in the air, drinking water and neighborhood environment, as well as everyday cleaning and beauty products, to serious health problems for mothers, young infants and babies in the womb.
Black and Latino communities appear particularly vulnerable. In L.A. County, these communities are found disproportionately in heavily polluted neighborhoods, and they suffer disproportionately higher rates of maternal and infant death.
All sorts of social determinants — such as poverty, quality of housing, access to good health care and obesity rates — can play a role in infant and maternal health outcomes. But experts have determined that institutionalized discrimination is the overarching cause for the high death rate among Black mothers and their infants. Over time, the stress this causes has a corrosive “weathering” effect on the body, predisposing Black women to chronic conditions like hypertension and gestational diabetes that put them at higher risk during pregnancy.
Environmental health experts say that exposure to toxic pollutants adds another layer of stress — another burden for the overburdened to shoulder. A March of Dimes report from last year, for example, found that environmental exposure was a key factor explaining the Black-white disparity in preterm births, a leading cause of infant mortality that’s linked to lifelong conditions such as behavioral development issues, learning difficulties and chronic disease.
Nevertheless, these same experts also warn that the overlap between environmental exposures and infant and maternal health outcomes is still largely unexplored. “Our system of health care is not doing its job,” says Tanya Khemet Taiwo, co-director of the Community Engagement Core at the UC Davis Environmental Health Sciences Center. “There are many people in power who are just waking up to the environmental part of this.”
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“So many factors go into the health of a baby,” says Bhavna Shamasunder, associate professor in the Urban and Environmental Policy Department at Occidental College. As such, she warns that parents need to be “super vigilant” about how chemical exposure in fetuses and very young children can damage their growing organs and bodily systems.
In the bread basket of California, the farming region of the San Joaquin Valley, children exposed to a common pesticide in the womb have been found to be more likely to develop attention disorders years later. Even miniscule levels of lead exposure in young children can cause neuropsychiatric disorders and antisocial behavior, and in pregnant women can cross the placenta to cause miscarriages, low birth weight and premature births.
“There’s a complex set of exposures that we have to think about that have genetic and environmental and long-term health implications that shape your life,” Shamasunder says, pointing out how fetuses and very young infants are often bombarded with many different toxic pollutants at once. The thing is, she adds, “We’re very bad at [determining] cumulative exposures.”
On that front, however, science is beginning to play catch-up.
Since 2015, a team of researchers out of the University of Southern California (USC) has been involved in a study examining the cumulative risks from living in environmentally and economically burdened regions like the heavily contaminated community around the former Exide lead-battery recycling facility in East L.A. The Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) study has primarily involved low income Latino women, with particular focus on maternal and childhood obesity outcomes.
“This is very much a high-risk population,” says Tracy Bastain, an associate professor at USC, and director of the MADRES Center for Environmental Health Disparities. Hispanic women are significantly more likely to suffer pregnancy-related obesity, for example, while Hispanic children are twice as likely as white kids to be obese by age 2. “The number of challenges that occur because of structural inequities really contribute to those poor outcomes that we’ve seen,” Bastain says, connecting the dots between pollution, poverty and poor health.
So far, more than 1,000 women have been enrolled and 800 babies have been born. And yet, “MADRES is still relatively new,” says Bastain. “The most important studies are yet to come.”
That said, those findings already published have helped peel the curtain back on some of the dangers for pregnant women who live in heavily polluted neighborhoods.
One key area of focus for the researchers has been air pollution, which disproportionately impacts people of color in the U.S. “Generally speaking, air pollution is not good for birth outcomes,” says Bastain. The MADRES researchers have found a “significant relationship” between exposures to multiple air pollutants and impaired growth of the fetus, with one common pollutant called PM10 — found in both industrial emissions and wildfire smoke — linked to reduced fetal weight mid-pregnancy, for example. Even short-term exposures to severe air pollutants can dangerously heighten a pregnant mother’s stress levels.
Aside from air pollution, researchers have looked at the health toll from heavy metals commonly found in the air, soil and drinking water of polluted regions, which lead to increased risk for pregnancy complications and stunted fetal growth. Newer, so-called emerging chemicals routinely found in the marketplace are proving potentially just as dangerous, like per- and polyfluoroalkyl substances (PFAS), a large family of ubiquitous “forever” chemicals found in everyday items such as clothing, food packaging and carpets.
There are more than 6,300 individual PFAS variants, and most people in the U.S. have at least one of them in their blood. One MADRES study has found that high blood levels of just one common PFAS chemical is linked to smaller fetal head circumference, and researchers speculate that PFAS exposures during critical periods of a baby’s growth can cause long-term developmental harm. A recent Environmental Working Group review of 40 separate studies found that every single one reported a wide range of PFAS in umbilical cord blood.
“When we see pregnant women who have chemicals that we know about, as well as chemicals that are newer on the scene that we don’t know much about, we really have to pay attention and figure out what their health consequences are,” says Matt Gillman, director of a National Institutes of Health program called Environmental Influences on Childhood Health Outcomes (ECHO). The program boasts about 70 participating groups around the country, including USC’s MADRES study.
Rather than seeking a direct link between toxic exposures and infant and maternal deaths, the ECHO program examines the way in which one’s environment can contribute to underlying health problems that make deaths more likely. In mothers, these problems include heart disease, strokes, high blood pressure and cardiomyopathy. The leading causes of death in babies include low birth weight, preterm births and chromosomal abnormalities.
“If we find that certain chemicals are related to adverse birth outcomes, what we want to know is the sources of those chemicals so we can take actions to reduce their harmful impact,” says Gillman, about a key aim of the program.
Worryingly for mothers and their families, chemicals suspected to cause some of these morbidities are found routinely inside the home as well as in the outside environment.
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Janette Robinson Flint is executive director of Black Women for Wellness, a South L.A. based nonprofit. Her work includes educating families about the potential health risks of using certain beauty and cleaning products. And she’s frustrated.
“It’s understudied — absolutely understudied,” Robinson Flint says, of the relationship between chemicals found in commonly used beauty and cleaning products and any effect they may have on pregnant women and their babies. But what is clear, she says, is that communities of color “are overexposed and underprotected.”
Irrespective of socioeconomic status, women of color are disproportionately exposed to more toxic chemicals than white women, and to more endocrine disruptors in particular. These are chemicals that can alter the body’s hormone response networks. Shanna Swan, a noted expert in endocrine toxicology, has found a link between endocrine disrupting phthalates and Bisphenol A — chemicals found in common items like plastic food packaging — and declining fertility rates. Black women in America suffer higher rates of endocrine-related health issues like diabetes, fibroids and certain cancers.
“Exposure to hormone disrupting chemicals changes the probability of having a healthy and successful pregnancy and birth,” says Robin Dodson, associate director of research operations with the Silent Spring Institute, an independent scientific research organization.
To get a better understanding of the problem, Black Women for Wellness and Silent Spring teamed up with a number of local organizations on a recent study looking at the use of personal consumer products among a racially and ethnically diverse array of women in California.
The researchers behind the Taking Stock study concluded that women of color in California — and Black women in particular — are at higher risk of being exposed to cancer-causing chemicals through their use of everyday consumer products than other groups. The report advocates for an overall reduction in beauty product usage, especially fragranced products and those containing endocrine disrupting parabens and phthalates. But the recommendations of Robinson Flint and other experts go only so far — what would help more is a health care workforce better trained and educated in environmental health.
“What is it going to take to bring environmental education into medical schools?” says UC Davis’ Tanya Khemet Taiwo. “Part of the problem is that schools don’t really want to teach anything that’s not on the board. They’re worried students won’t pay attention if it’s not on the board. So, why don’t we change the board exams?”
Experts also urge the nation’s public health departments to better educate and protect vulnerable communities.
“There have been some conversations but there’s not a lot of programmatic work at this point,” says Deborah Allen, deputy director of the L.A. County Department of Public Health, about forging stronger links between the department’s separate programs for environmental health and infant and maternal health. “But it is something I’m very interested in. In particular, in communities where there has been something found that is a smoking gun environmentally — a Superfund site or a lead exposure.”
Ultimately what’s needed, many environmental experts argue, is systemic change of the nation’s overly permissive chemical regulations, in order to remove dangerous toxins before they enter the air and water. Removing pollutants at the root source would most benefit those least able to escape harm’s way — people like Bell-Holt, who would like to move to cleaner greener pastures but can’t afford to.
“For the size of the house we have, it would cost me a great amount to move elsewhere,” says Bell-Holt, about the six-bedroom Victorian home in which she has raised her children. And though she champions a new California law that will prohibit the drilling of new oil wells within 3,200 feet of residential neighborhoods, it doesn’t ban existing wells within those areas. Says Bell-Holt about herself and her family, “We don’t matter.”
Copyright 2022 Capital & Main.
This article was produced as a project for the USC Annenberg Center for Health Journalism’s 2022 California Impact Fund.