Babies from the most polluted neighborhoods of southeast Louisiana were 4.3 times as likely to have a severe congenital heart defect as babies from the least polluted ones, according to a peer-reviewed study published last week in the journal Environmental Health. Babies from neighborhoods with intermediate pollution had 3.1 times the odds.
The neighborhoods in question sit along the Mississippi River between Baton Rouge and the Gulf, the stretch known as Cancer Alley, where more than 350 industrial facilities, mostly petrochemical plants, operate. The communities around them are disproportionately Black and low-income. The researchers matched the infants they compared on race, so the gap they found is not explained by it.
The team, led by Dr. Kelly Gajewski, a pediatric cardiologist at Manning Family Children’s Hospital and LSU Health Sciences Center, looked at 454 infants born with congenital heart defects between 2018 and 2022 and treated at Manning or Ochsner Children’s Hospital, the only two facilities in Louisiana that can perform surgery for these defects. Of those babies, 194 had defects serious enough to need an operation. Thirty-eight died during the study period.
Exposure was estimated from the EPA’s risk-screening database, which draws on emissions that companies report themselves, run through a scientific model. The chemicals include benzene, formaldehyde and toluene, plus at least 17 others known to harm unborn babies. The Environmental Integrity Project says the study is the first peer-reviewed work to document a clear link between toxic industrial air and severe heart defects.
“Our study suggests that Louisiana’s health burden from industrial pollution starts in the womb,” said Dr. Kimberly Terrell, a co-author with the Environmental Integrity Project.
The limits are real, and the authors state them. Modeled exposure cannot capture where a mother actually spent her days or what she breathed indoors. A case-control design shows an association, not proof of cause, and unmeasured factors such as income cannot be fully ruled out.
But the finding lands on ground already marked by earlier work. Terrell’s 2022 study in Environmental Research Letters found that the link between toxic air and cancer was strongest in neighborhoods with more Black or poor residents. Louisiana’s infant mortality rate in 2022 was 7.4 per 1,000 live births, against 5.6 nationally, and the state’s industrial plants emitted 48 million pounds of pollutants that year, compared with a national average of 10 million.
The study’s authors call for new research on whether the EPA’s “acceptable risk” thresholds actually protect the most exposed, and for better air monitoring to guide cuts in emissions. The article reports no response from industry or state officials.
Those thresholds were set without asking the families who live behind the fence line. A state that permits plants to pile up in Black neighborhoods owes those families a monitor on every block and a cap that is judged by what happens to their newborns. Louisiana’s regulators now have the data to start.
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