The Whole View, Episode 464:  Forever Chemicals: What are PFAS?
Welcome back to episode 464! (0:28)

Science has shown, pretty unequivocally, how harmful these chemicals are for decades. It's not recent science. And what we see in modern days is regulatory agencies not being able to keep up with capitalism demands.

This topic is difficult to see in something other than a "conspiracy" lens. But that is why it's important to Stacy and Sarah now, more than ever, to make sure they stick to scientific research as much as possible.

There are specific areas known to have high levels of PFAS. If you know you're in one of those areas, it's possible to test your blood for your exposure levels.

Stacy reminds the audience that she and Sarah are not medical professionals. So, if you have any health concerns around this topic, be sure to see a doctor.

 

What Are Forever Chemicals?
PFAS are a class of man-made chemicals used to make products greaseproof, waterproof, and stain-resistant. (7:30)

They are "forever chemicals" because they and their breakdown products are extremely persistent, lasting thousands of years or more. But, unfortunately, we have no way to speed up the breakdown, so they end up bioaccumulating in the environment and our bodies.

Of the more than 9,000 known PFAS compounds, the U.S. uses 600 alone!

Countless products, including firefighting foam, cookware, cosmetics, carpet treatments, and even dental floss, contain PFAS compounds.

PFAS stands for perfluoroalkyl and polyfluoroalkyl substances- chemicals with at least one aliphatic perfluorocarbon moiety (e.g., -CnF2n-).

PFAS includes multiple subclasses of chemicals:

PFAA - perfluoroalkyl acids and perfluoroalkylether acidsPFOS - perfluorooctanesulfonic acid 

PFOA - perfluorooctanoic acid (C8, used to make PTFE polytetrafluoroethylene, aka Teflon)




PFAA precursors

Fluoropolymers

Perfluoropolyethers

other (primarily less reactive) PFAS 


The most consistent feature within the class of PFAS is that their perfluorocarbon moieties do not break down or do so very slowly under natural conditions. This is why PFAS have often termed "forever chemicals."

Because PFAS are persistent, they accumulate or concentrate in the environment, including water, air, sediment, soil, and plants.

Elevated levels of PFAS and their widespread presence in environmental media and drinking water stem from industrial sites that produce or use PFAS, airports, military bases (fire-training and response areas), landfills, wastewater treatment plants, and the spreading of PFAS-contaminated biosolids.

Some PFAS are highly mobile in either air or water. This allows them to travel long distances from their sources. 

It's important to note that we don't metabolize PFAS molecules.

Sarah recommends this great article and this review for more information. 

 

How Do They Harm Health?
A better question might be how do they not harm health because their detriment is incredibly pervasive. (10:50)

Data from toxicokinetic studies of PFAA indicate that they are generally well-absorbed after ingestion.

After absorption, they distribute blood to organs and tissues that receive high blood flow, such as the liver, kidney, lung, heart, skin, testis, brain, bone, and spleen.

Because PFAA can occupy sites on multiple receptors, proteins, and cell interfaces in the body, they can produce physiological effects across various tissues.

Nine nuclear receptors are activated (controls gene expression), including PPAR-alpha, which controls fatty acid beta-oxidation and is a major regulator of energy homeostasis. 

They also bind to a variety of serum proteins, including steroid hormones and albumins, which are transport proteins (e.g., vitamin D-binding protein) 

Scientists have found direct links (with mechanisms identified) between PFAS exposure and kidney and testicular cancer, thyroid disease, liver damage, developmental toxicity, ulcerative colitis, high cholesterol, decreased fertility, pregnancy-