Part 1: The silent spread of PFAS
What it means for our health and planet
This article is the first in a series exploring PFAS1 – a type of pollutant that has infiltrated nearly every aspect of modern life. Often called "forever chemicals," these substances are everywhere. I started to look into the topic (and problem) of PFAS last autumn and have been concerned since then. In this article I explore why hikers, cooks and firefighters benefit from this innovation while also examining its lasting impact on (planetary) health.
Foto von Matt & Chris Pua auf Unsplash
PFAS: A modern plague.
PFAS are synthetic human-made compounds renowned for their ability to repel water, grease and stains. They are also chemically very stable and heat-resistant. These properties make them excellent for keeping our pans slick, our rain jackets waterproof and even for extinguishing fires. Next to these uses, PFAS is widely used in countless industrial processes as seals, lubricants or membranes. What exactly do we mean when we talk about PFAS? First, PFAS isn’t a single substance, but it is a family of of more than 15,000 different chemicals2. Second, from a chemistry perspective, PFAS are persistent organic substances all built around a carbon chain in which hydrogen atoms are fully or partly replaced by fluorine3. Their advantage? Near-indestructibility. Their problem? The same.
The extraordinary resistance to degradation has led to widespread use, but also widespread contamination of air, soil, water and even the human body. Water-soluble forms of PFAS can leach into ground4water and rivers, creating contamination hotspots and leading to accumulation in the food chain5. PFAS are even detected in remote Arctic environments and deep ocean sediments, far from their original sources6. In short: they don’t break down and they just keep spreading.
What exactly is so bad about PFAS in living organisms?
Unlike many other harmful substances, PFAS binds to proteins in the blood and organs – instead of being stored in fat7 – where they can interfere with critical biological processes leading to a range of health concerns8. Their persistence combined with bioaccumulative properties9 causes PFAS to be present at high levels in living organisms.
Scientific studies have linked PFAS exposure to numerous health problems, including:
Higher risks of cancer, particularly kidney and testicular cancer10
Weakened immune system, making it harder to fight infections11
Hormonal imbalances that affect metabolism and growth12
Pregnancy complications, like high blood pressure and reduced fertility13
Developmental issues in children, including low birth weight and behavioral changes
Even at low exposure levels, PFAS can disrupt the body's natural systems, leading to long-term health consequences and increased healthcare costs in the upcoming decades. A recent study14 by the U.S. Environmental Protection Agency (EPA) highlights the severe health risks posed indirectly by using sewage sludge from wastewater treatment as fertilizer, as the presence of PFOA and PFOS can exceed acceptable safety thresholds when land-applied or surface-disposed15.
Not all PFAS chemicals are equally toxic, but none of them studied are benign to living organisms. Research16 shows evidence of toxicity for specific subgroups - and the list of such subgroups is continuously expanded. For a long time there has been a general perception that short-chain PFAS are less problematic than long-chain forms but this has turned out to be an oversimplified view. There are other factors besides the extremely strong bond between carbon and fluoride that may affect the stability of the molecule; its structure, for example17. Some of the most harmful PFAS, like PFOS and PFOA18, are restricted under the Persistent Organic Pollutants (POPs) Regulation19 in Europe and designated as hazardous substances by the U.S. EPA20. Recently the EU is pushing for one of the broadest restrictions to date21 aiming to restrict over 10,000 PFAS compounds across all industries.
PFAS pollution in drinking water is a major concern, with 20 million Europeans exposed to levels above the proposed new limits. The safe intake threshold for certain PFAS has been slashed to 4.4 ng/kg body weight — just a fraction of the recommendation 10 years ago. The scale of contamination is alarming, in England alone there are estimated 10,000 PFAS contaminated locations where the recommended limits are exceeded22.
Cleaning up the mess
More pollution not only leads to higher health costs, but also to higher costs to clean up our mess. Recently the Guardian reported that the estimated global societal costs of PFAS pollution could reach $17.5 trillion with cleanup costs being the largest financial burden.
In Minnesota alone, removing PFAS from wastewater could cost up to $28 billion over two decades23. The price of remediation vastly outweighs the cost of production – destroying just one pound (around 0.45 kg) of PFAS from municipal wastewater can cost up to $18 million while producing it costs $50 to $1,00024. Meanwhile, legal settlements are piling up: Chemours, DuPont, and Corteva25 settled PFAS contamination claims for $1.19 billion in 2023, while 3M agreed to pay $10.3 billion over 13 years for PFAS cleanup in drinking water26. As regulations tighten and costs soar, industries face mounting pressure to take responsibility for PFAS contamination.
In short: PFAS are everywhere, they last forever, are harmful and have to be cleaned up. Read our next blog post (a more positive one!) on how we can get rid of PFAS and which scientists are working on breakthrough technologies in that space. If you share concerns about PFAS and are working on hardware solutions to mitigate its impact, we’d love to hear from you! (feel free to write to scientists@positron.vc)
Per- and polyfluoroalkyl substances (PFAS).
Currently there is no internationally agreed definition of PFAS, but in 2021 OECD (the international organisation for economic cooperation and development) concluded on a PFAS definition which has gained wide acceptance: PFAS = substances that contain at least one fully fluorinated methyl group (-CF3) or fully fluorinated methylene group (-CF2-) without any hydrogen, chlorine, bromine, or iodine atoms attached to it.
Therefore, leading to their pervasive presence in animals and humans.
There is considerable evidence to suggest that the longer the fluorinated carbon chain is, the greater the bioaccumulation. (Source)
One example of a structural form similar to long-chain PFAS is short-chain PFAS ethers, which feature strong oxygen-bridge bonds connecting multiple short perfluorinated chains into a single long and stable chain.
Compounding the issue, newer short-chain PFAS compounds are up to 70% more expensive to remove and destroy compared to older long-chain variants.