Join host Ryan Feldman in an insightful episode of "The Poison Lab" as he sits down with Dr. John Downs, Director of the Virginia Poison Center, and one of the leading experts on per- and polyfluoroalkyl substances (PFAS), commonly known as "forever chemicals." Known for their persistence in the environment and human body, PFAS have raised significant public health concerns over the past few decades. Dr. Downs shares his journey through occupational medicine, toxicology, and public health, which uniquely positioned him to provide expertise on PFAS exposure, health risks, and ongoing regulatory efforts. Together, they delve into the origins, uses, and potential health effects of these ubiquitous compounds, while examining government policies, environmental impact, and strategies to reduce exposure. A must-listen for anyone interested in the intersection of environmental health and toxicology!

Episode Breakdown:

• 2:42 – What Are Forever Chemicals?
• 8:01 – History of PFAS and Associated Health Concerns
• 15:41 – Government Regulation of PFAS
• 20:42 – Shortcomings in PFAS Regulation
• 25:20 – How Individuals Can Mitigate Risk
• 31:15 – Testing for PFAS Levels and Exploring Treatment Options
• 41:14 – Future Directions and Research Needs for PFAS
• 45:29 – Conclusion and Outro

Key Topics Discussed

2:42 – What Are Forever Chemicals?

• PFAS are a large group of man-made chemicals that are persistent in the environment and human body.
• The podcast focuses primarily on PFOA (perfluorooctanoic acid) and PFOS (perfluorooctanoic sulfonic acid), as these were the first compounds identified as having very long elimination half-lives, measured in years, and not undergoing significant human metabolism
• The podcast mentions that there are potentially thousands of different PFAS compounds and that more research is needed to determine if they all induce the same health effects as PFOA and PFOS
• Commonly used for their water- and oil-resistant properties in nonstick cookware, fast food wrappers, firefighting foams, and more.

8:01 – History of PFAS and Associated Health Concerns

• First created by Dupont chemical, used widely in 1940's in Teflon
• Large contamination of water by PFAS identified in West Virginia town
• Led to landmark study in West Virginia (the C8 study) on epidemiological data of PFAS-related health risks.
• Effects noted: High cholesterol, thyroid dysfunction, ulcerative colitis, hypertension in pregnancy, decreased immune response to vaccine, and certain cancers (testicular and kidney cancer).

PFAS in the Environment

• PFAS are not easily degraded, leading to bioaccumulation in humans and animals.
• Non-stick cookware: Teflon, the trade name for non-stick cookware, was one of the earliest applications of PFAS, utilizing PFOA.
• Firefighting foam: PFAS was used in firefighting foams, particularly for aviation fuel fires. This has led to contamination of groundwater around military installations and airports.
• Fast food wrappers and other consumer products: PFAS are used to make products water and oil resistant, including fast food wrappers, clothing, upholstery, and popcorn bags.
• Biosolids: The nitrogenous waste produced after wastewater treatment, have been found to contain concentrated PFAS. These biosolids are sometimes sold to farms as fertilizer, potentially contaminating water and crops.
• Ski wax: Ski waxers have been found to have a high degree of PFAS exposure10.
• Major sources contaminated drinking water, military bases, and consumer product (Teflon, waterproof jackets, popcorn bags etc...)

15:41 – Government Regulation of PFAS

• EPA Health Advisory Limits (2009): These were the first non-enforceable limits set for PFOA and PFOS in drinking water. These limits were revised several times over the next 15 years, becoming progressively lower.
• EPA Enforceable Limits (2024): The EPA published its final rule for enforceable limits, known as maximum contaminant levels (MCLs), in April 2024.
• The goal is for PFOA and PFOS to be completely non-detectable in drinking water
• Recognizing that non-detect is difficult to achieve, the EPA set an MCL of 4 parts per trillion for both PFOA and PFOS.
• A combined limit of 10 parts per trillion was set for four other unspecified PFAS compounds.

Practical Steps for Individuals

• Tips for reducing personal PFAS exposure, such as using alternative cookware, avoiding certain fast-food packaging, and considering home water filtration.

The Future of PFAS Management

• Ongoing need for more research to fully understand PFAS health impacts and develop effective mitigation strategies.
• He discusses potential alternatives to PFAS and the importance of balancing industrial needs with public health concerns.

Additional Resources

• Books: Exposure by Rob Bilott (inspiration for the film Dark Waters)
• CDC and EPA websites for information on PFAS and water quality testing
• Dr. Downs guidance from the American College of Medical Toxicology