‘Forever Chemicals’ Thought to Be Making Alligators Sick in Cape Fear River

by Craig Garrett
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Very Large Alligator sunning itself - stock photo

A study found that alligators in North Carolina’s Cape Fear River exposed to “forever chemicals” may be experiencing autoimmune effects. The study, which was printed on Thursday in Frontiers in Toxicology, found that the animals had many infected lesions. The animals also showed genetic signs of impacts relating to their immune system, The Hill reports.

In a statement, Scott Belcher – a professor of biology at North Carolina State University said that alligators “rarely suffer from infections.” When they do get wounded, they normally heal quickly, Belcher explained. In order to study the alligator population, Belcher and his team collected blood samples and did health checks on 49 animals living along the Cape Fear River over the course of a year.

The animals had high levels of 14 different types of what are called “forever chemicals.” These chemicals are also known as per- and polyfluoroalkyl substances (PFAS). There are thousands of types of PFAS — manmade compounds that can last for decades in the environment. They have been linked to many health issues, like thyroid disease and kidney cancer. While you might only think of PFAS with their presence in jet fuel or firefighting foam. However, these chemicals are also key things found in a variety of household items, like non-stick pans and waterproof apparel.

For years, industries have discharged PFAS into the Cape Fear River basin located in central and coastal North Carolina, contaminating 9000+ square miles of waterways that serve 5.2 million residents. The authors noted that upstream contamination in Cape Fear largely has come from fluorochemical production, manufacturing, wastewater treatment discharges, and the use of firefighting foams.

The study found multiple PFAS present in alligator blood samples

Belcher and his team discovered that on average, 10 different types of PFAS existed in their blood samples. They compared them to a group of 26 alligators from Lake Waccamaw. This lake is located in the shared Lumber River basin. The scientists noted an average of five various types of PFAS present.

The researchers noted that overall PFAS concentrations decreased as they moved downstream from Wilmington. The authors’ most unexpected finding, however, was the sheer number of unhealed wounds on the alligators. “Seeing infected lesions that weren’t healing properly was concerning. [It] led us to look more closely at the connections between PFAS exposure and changes in the immune systems of the alligators,” Belcher explained.

The scientists did a genetic analysis. They discovered that the alligators had 400 times higher levels of genes responsive to an immune protein called interferon-alpha. This was in comparison to Lake Waccamaw alligators.

Belcher explained that the set of interferon-alpha responsive genes normally involved in viral infections were identified in the alligators. In humans, he continued, high expression of these genes is an important sign of autoimmune diseases- such as lupus. Some PFAS in people has already been linked to chronic autoimmune disorders, as Belcher observed.

“Alligators are a sentinel species – harbingers of dangers to human health,” Belcher explained. “Seeing these associations between PFAS exposure and disrupted immune function in the Cape Fear River alligators supports connections between adverse human and animal health effects and PFAS exposure,” he said. 

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