High Levels of Forever Chemicals PFAS Exposure Causes Adverse Immune System Effects on Cape Fear Gators

Gators in the Cape Fear River were the subject of a recent study that discovered the animals had elevated blood serum levels of 14 different perfluoroalkyl and polyfluoroalkyl (PFAS) chemicals in addition to genetic and clinical indicators of impacts on the immune system.

The study expanded the body of research linking PFAS exposure to unfavorable immune system effects.

49 Gators, 23 Forever Chemicals PFAS

On 49 alligators that lived along the Cape Fear River between 2018 and 2019, the research team, under the direction of Scott Belcher, an associate professor of biology from the North Carolina State University, collected blood samples and assessed the health of the animals.

These findings were contrasted with the 26 alligators from the nearby Lumber River basin's Lake Waccamaw, which were the reference population.

Belcher said that they examined 23 different PFAS and discovered distinct variations in the types and concentrations of PFAS detected in the two populations.

Comparatively, the Lake Waccamaw population had an average of five distinct PFAS, while the Cape Fear River samples had an average of ten different PFAS.

Additionally, according to Belcher, Alligators from the Cape Fear River basin had higher blood concentrations of fluoroethers like Nafion byproduct 2, whereas these levels were much lower, or close to undetectable, in alligators from Lake Waccamaw.

Their findings demonstrated that overall PFAS concentrations decreased as the research transitioned downstream from Wilmington towards Bald Head Island.

Long-Lasting Lesions

The team's most peculiar discovery, however, was that a number of the Cape Fear gators had unhealed or infected lesions.

Belcher said that gators very rarely get infected and do get wounds, but they typically recover quickly.

Concerned by infected lesions that haven't been healing properly, the team decided to focus on the relationships between PFAS, or forever chemicals exposure, and alterations in the alligators' immune systems.

A qRT-PCR genetic analysis found that the interferon-alpha (INF-α) responsive genes were 400 times more abundant in the Cape Fear River alligators than in the Lake Waccamaw gators, which had much lower blood concentrations of PFAS.

Belcher explained that a secreted immune protein called INF-α plays a role in triggering an immune response.

The group examined a set of INF-α responsive genes that are typically associated with viral infections.

Long-term or chronic high expression of this group of genes in humans is a significant sign of autoimmune disorders, particularly lupus.

Furthermore, some human PFAS exposures have been associated with long-term autoimmune conditions like ulcerative colitis and thyroid disease.

He explained further that, therefore, elevated INF-α expression in these alligators indicates a disruption in one or more aspects of their immune systems.

According to NC State University News, the researchers are in a good position to continue observing PFAS exposure and health differences in both individuals and the larger alligator populations within both habitats because they have data samples for the past five years, much of it collected from the same gators on an annual basis.

Human Health Too

According to Belcher, alligators are sentinel species that signal health risks to humans.

These connections between exposure to PFAS and impaired immune function in Cape Fear River gators provided evidence that PFAS exposure has negative effects on both human and animal health, Phys Org reported.

The National Institute of Environmental Health Sciences, the North Carolina Policy Collaboratory, and the North Carolina Sea Grant all provided funding for the research that was published in Frontiers in Toxicology.

The project, which was created in association with Cape Fear River Watch and the PFAS testing network, has Belcher as its corresponding author.