Babies in Louisiana's industrial pollution hotspots face over four times the risk of heart defects, study finds

Babies born to mothers in parts of Louisiana with high levels of industrial pollution are more than four times more likely to suffer severe congenital heart defects than infants from low-pollution areas, a study of babies hospitalised in New Orleans has found.

The study, published last week in the journal Environmental Health, reviewed medical records for 454 infants at the two major Louisiana hospitals that can provide surgery for heart defects in babies. Researchers traced back where the mothers of these infants lived.

Using the US Environmental Protection Agency's risk-screening database, the researchers measured the levels of industrial toxic pollution in those mothers' communities. Compared to infants from low-pollution areas, the odds of congenital heart defects were 4.3 times higher for infants from toxic hotspots, and 3.1 times higher for infants from places with intermediate levels of pollution.

Some of the babies in the study were patients of Dr Kelly Gajewski, a paediatric cardiologist at Manning Family Children's Hospital and a professor at Louisiana State University Health Sciences Center. She said it is very anxiety-producing to have a baby that has congenital heart disease.

When Dr Gajewski moved to Louisiana more than a decade ago, she thought she was seeing a lot more cases of severe congenital heart disease in children. She had suspicions that there was something in the state leading to higher rates, and that led her to explore environmental factors as possible contributors.

The study's lead author, Kimberly Terrell, a research scientist with the Environmental Integrity Project, said the study shows the impact of industrial pollution on Louisianans' health starts in the womb. Serious health effects are usually associated with cancer and chronic lung disease from long-term exposures, she said, but developmental impacts come from fairly short exposures.

Terrell added that early in pregnancy is the critical window for heart development and the development of other body systems, so there is a narrow three-month window where reducing these exposures is especially critical.

The researchers looked at infants born from 2018 to 2021 and their mothers' potential exposure to 20 toxins known to cause adverse effects during early development, including benzene, formaldehyde and toluene. Cases where the mother was recorded as having smoked, consumed alcohol or had diabetes during pregnancy were left out of the study.

Explaining that exclusion, Terrell said the team wanted to focus on the births that would be expected to be healthy, and that it can confidently be said this risk is not attributable to smoking, alcohol or diabetes.

Louisiana has among the highest rates of infant mortality and industrial emissions in the United States. Previous studies have linked the state's toxic air pollution to low birthweights and high cancer rates among Black and impoverished communities. Petrochemical facilities are the largest source of toxic pollution in the state.

According to the Centers for Disease Control and Prevention, a baby is born with a heart defect in the US every 15 minutes. About 15 percent of infants born with critical forms of heart defects do not survive their first year of life. Of the 454 babies in this study, 194 of the cases were severe and 38 of the babies died during the study's timeframe.

Dr Gajewski said that although modern medical care can save the lives of babies born with serious heart defects, almost all of these children will continue to need specialised care and will face higher risks of learning disabilities, mental health disorders, heart failure or other organ problems during their lifetime. She added that the parents of some of her patients move to New Orleans to be closer to the hospitals where their children are receiving care.

The study team suggests that fewer babies in south-east Louisiana would be born with life-threatening heart defects if maternal exposure to industrial pollution was reduced. On whether that can happen, Terrell said that if there is political will, it can.