There are too many PFAS in water and soil all over the world. This has irreversibly crossed a limit of the planet. Swedish researchers write that this week Environmental Science & Technology. The four most notorious substances are so widespread that they exceed limit values everywhere and affect people’s health.
PFAS, short for poly- and perfluoroalkyls, are thousands to millions of different chemicals that have been widely produced since the 1950s. The molecules contain bonds between carbon and fluorine atoms, which gives them unique but also extreme properties. The list of products they contain is endless. Many PFAS are both water and grease repellent. This is a special combination that makes them useful in, for example, pans and raincoats.
It is now also clear that the substances are harmful. They don’t break down, so they’ve accumulated in the environment for decades. A large proportion of the PFAS are also ‘bio-accumulative’, meaning they can accumulate in humans over life. And some PFAS are toxic: they disrupt the immune system. This reduces the effectiveness of vaccinations, especially in children. At higher concentrations, they can be carcinogenic, cause liver damage and raise blood pressure in women, among other things. RIVM established last year that the Dutch ingest so much PFAS through food and drinking water that it can be harmful to the immune system.
Now researchers show that four specific PFAS cross a “planetary boundary.” This means that the substances cause so much damage that the earth cannot offer sufficient resistance to counteract the harmful effects. Climate scientists introduced the concept in 2009, establishing the existence of nine planetary boundaries. Most boundaries have now been crossed, such as in the area of climate change and biodiversity loss.
“People already suspected that the planetary boundary had been crossed, now it appears that this is the case for at least these four PFAS,” says Annemarie van Wezel. She is professor of environmental ecology at the University of Amsterdam. “This again shows that we have to be extremely careful with the use of persistent substances in particular, which accumulate in the environment. We need to be more critical about whether such substances are really needed in everyday life, and regulations need to be much stricter.”
The researchers compared the PFAS levels in rainwater, soil and surface water worldwide with international and national guidelines in various areas. These are the substances PFOS, PFOA, PFHxS and PFNA, which are among the most widespread and more harmful PFAS. The concentrations in rainwater and surface waters far exceed American and European limit values. In addition, guidelines for soil quality proposed by the Netherlands are not being achieved worldwide, because PFAS ends up in the soil via rain.
The problem is virtually irreversible, the researchers write. This is because the substances in the environment do not break down and move effortlessly around the world via air and rainwater. The Netherlands has been working on a total ban on non-essential PFAS in Europe since last year. It is difficult to eliminate all PFAS, as many PFAS, for example in fire fighting foam, are of social value. PFOS and PFOA are already banned in most countries.
Also read: PFAS: harmful and unbreakable