High Levels of Toxic PFAS Chemicals Giving Alligators Lupus: Study

A new scientific study has found that high levels of toxic PFAS* discharged from an industrial plant into the Cape Fear River in North Carolina has contaminated the water and is the likely culprit for making alligators sick with autoimmune disorders that appear similar to human diseases like lupus.


Study overview

The new study compared Cape Fear alligators with a cohort from Lake Waccamaw in a neighboring watershed not subjected to direct PFAS pollution.  Researchers found that alligators living near the industrial plant that is dumping PFAS into the water have extremely high levels of PFAS compounds and markers of immune disease in their blood.

Additionally, the expressions of interferon-alpha responsive genes in the Cape Fear River alligators were 400 times higher than those alligators in the control group from Lake Waccamaw.  (Alligators further from the industrial plant showed lower levels of PFAS and lower expressions of interferon alpha.) Interferon alpha is a secreted immune protein involved in stimulating immune response, and the type that the research team checked for responds to viral infections. In humans, long-term high expression of this gene set is an important indicator of autoimmune disease, especially lupus.

The most unusual finding was a high number of unhealed or infected lesions on the alligators’ skin, which is highly uncommon–alligators’ lesions usually heal quickly, and this finding suggests immune system interference.

*PFAS are a class of about 12,000 chemicals often used to make personal care, cosmetics, clothing, cooking and home care products resist water, stain and heat. They are called “forever chemicals” because they do not naturally break down in the environment or the bodies of humans or other animals. PFAS chemicals are known endocrine-disruptors (triggering hormonal imbalance and subsequent health problems) and are linked in scientific and medical studies to cancer (including prostate cancer), liver problems, thyroid disease, birth defects, kidney disease, immune system dysfunction (like ulcerative colitis), adverse effects to the gut microbiome (triggering digestive disorders), and other serious health problems.

Journal reference: T. C. Guillette, Thomas W. Jackson, Matthew Guillette, James McCord, Scott M. Belcher. Blood concentrations of per- and polyfluoroalkyl substances are associated with autoimmune-like effects in American alligators from Wilmington, North Carolina. Frontiers in Toxicology, 2022; 4 DOI: 10.3389/ftox.2022.1010185

Sun, M., et al. Legacy and Emerging Perfluoroalkyl Substances Are Important Drinking Water Contaminants in the Cape Fear River Watershed of North Carolina, Environmental Science & Technology Letters, DOI: 10.1021/acs.estlett.6b00398

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