This story was originally published by Louisiana Illuminator
A new report is sounding the alarm over the presence of harmful chemicals and heavy metals in Southeast Louisiana’s drinking water.
The Southeast Louisiana Residential Water Quality Study, conducted by the Water Collaborative of Greater New Orleans, tested for contaminants in home tap water from seven parishes. Nearly every home among the 107 total tested in St. James, St. John the Baptist, St. Charles, Jefferson, Orleans, St. Bernard and Plaquemines parishes had at least trace amounts per- and polyfluoroalkyl substances, or PFAS for short.
The consumption of PFAS – also known as “forever chemicals” because they don’t naturally degrade – has been linked to high cholesterol, liver damage, increased risk of thyroid disease and reduced vaccine response in children.
PFAS have widespread uses in consumer and industrial products, including nonstick cookware, cleaning products, carpets, waterproof clothing and firefighting foam. As contaminants, they have been found in air, water, soil and fish.
The study was conducted to inform residents about the long-term health risk of low-level exposures to lead, arsenic and PFAS “even when most detections fall below enforceable limits,” according to the study.
Out of 107 homes tested in the study, 105 had at least one detectable PFAS. The study did not report any differences between parishes that get their drinking water from aquifers – St. James and St. John – and those that draw their supply from the Mississippi River.
The study also tested for other contaminants, including excessive heavy metals and salt levels.
Varying amounts of arsenic were found in 70% of samples, and lead was present in 67%. Salt levels exceeded the Environmental Protection Agency’s recommended thresholds for drinking water quality in 100% of the samples taken during low water levels for the Mississippi River.
Taya Fontenette, who led the study as policy coordinator for the Water Collaborative, said that while the testing provides just a snapshot of what people can be exposed to in drinking water, “these small amounts of exposures can add up, which is why ongoing monitoring and mitigation is important.”
The amounts of PFAS and heavy metals detected were below levels federal health officials deem harmful, but there is consensus among physicians that no amount is safe.
PFAS concentrations measured in the study ranged from trace amounts to one instance in Plaquemines Parish where the sample measured 43% above the pending federal limit.
Regulations limiting the amount of PFAS allowed in drinking water, first introduced during the Biden administration in May 2024, were partially rolled back under the Trump administration this past May. The effective date for the new limits was also pushed forward from 2029 to 2031, with some PFAS maximums removed entirely.
“Something that makes PFAS unusual, compared to the vast majority of chemicals that we toxicologists study, is that PFAS dissolve in water. Now PFAS also contaminate the drinking water of millions of Americans,” said Jennifer Schlezinger, an environmental health professor and toxicologist at Boston University School of Public Health who assisted in the study.
Researchers tested for 18 different PFAS compounds, seven of which were detected at least once across the study. Perfluorooctanoic acid and perfluorooctane sulfonic acid were, by far, the most frequently encountered, appearing in 97.2% and 72.9% of tap water tested, respectively.
Homes were chosen for testing to reflect the makeup of Louisiana’s population, Fontenette said. The results revealed “sharp disparities” in terms of who was exposed to contaminants. While white households had more frequent detections, Black and lower-income households recorded the highest concentrations when it came to heavy metals.
This same trend in heavy metal exposure appeared across income and educational differences.
Study subjects with a high school education or less, as well as those earning under $25,000 a year, recorded the highest peaks in heavy metal exposure, while more educated, higher-income groups recorded generally lower levels of exposure.
PFAS appeared to contaminate more uniformly across race, education and income, with widespread detection in smaller amounts.
“That variation shows how different the challenges can be depending on where you live, how your water is treated and how your water is delivered to you, either through public or private plumbing,” Fontenette said. “Our results show that stronger safeguards are needed to protect Louisiana residents.”
“Clearly there is a need to regulate PFAS. We know that they’re found in drinking water, and we know that they are dangerous to human health,” Schlezinger said.