First up is Hans Peter Arp, a professor of environmental chemistry at the Norwegian Geotechnical Institute and Norwegian University of Science and Technology in Oslo. He also sits on the management board of the European Chemicals Agency (ECHA).*

Hans Peter has been researching the environmental effects of persistent chemicals such as PFAS for several years. We wanted to ask him: Just how big is the PFAS problem?

Hans Peter, please explain why PFAS are a “planetary threat”.

Well, let’s start with a cautionary tale. The late environmentalist James Lovelock was the first to detect chlorofluorocarbons (CFCs) in the atmosphere back in the early 1970s. He believed they were harmless, stating that they pose “no conceivable hazard”.

What he didn’t realise was that the breakdown of CFCs in the stratosphere would pose a serious threat to the ozone layer. Even as concerns emerged about ozone depletion, Lovelock remained sceptical.

But scientific evidence grew about the mechanism of chlorine radicals released from CFCs destroying ozone, and then the ozone hole was discovered. This prompted the Montreal Protocol in 1987. Global production of CFCs plummeted. The agreement saved the planet. There are projections that if this did not happen, plant life would have been largely wiped out by now due to the depleted ozone layer.

“TFA appears to exhibit similar toxic impacts to other PFAS”

Are you saying PFAS are like CFCs?

Actually, I would like to make a different point. The story of the Montreal Protocol is one of substituting CFCs with chemicals that turned out to have other harmful effects. This is the cautionary tale. The Montreal Protocol banning CFCs was a great first chapter, but its story is not over.

In the second chapter, CFCs were replaced by other, much less ozone-depleting, chemicals (HCFCs). But these turned out to be potent greenhouse gases. So they were replaced with another set of chemicals (HFCs) in the third chapter of the Montreal Protocol. These were less powerful greenhouse gases and were not ozone depleting. They belong to a group of gases called F-gases (fluorinated gases) because they do not contain chlorine. However, many of these HFCs lead to the formation of trifluoroacetic acid (TFA), an extremely persistent and mobile short-chain PFAS.

In 2016, in an attempt to lower the greenhouse gas impacts, these chemicals were replaced by hydrofluoroolefins (HFOs) – another type of F-gas – which have even less global warming potential. However, these break down into even larger quantities of trifluoroacetic acid (TFA), an extremely persistent and mobile short-chain PFAS. A major reason is that the Montreal Protocol does not consider PFAS formation a key concern.

As a result, TFA is now accumulating rapidly everywhere at an unprecedented rate for any PFAS – in arctic ice cores, in leaves, and in groundwater. It is found in everything we drink, from beer and wine to tea and juice. I recently saw a study that showed extreme levels in insects. Of course it is found in human blood. That’s a big PFAS problem.

But some people say TFA is harmless?

That was the original assumption. It was the long-chain PFAS chemicals, such as PFOA and PFOS, that were considered toxic.

But scientific understanding of TFA is rapidly evolving. TFA appears to exhibit similar toxic impacts to other PFAS – it is mainly the dose required to manifest this risk that is different.  This has been shown with chronic liver toxicity in rats. There is emerging data suggesting that TFA affects the immune system, and pharmacologists have long recognized links to neurotoxicity.

And now, ECHA’s risk assessment committee may be about to propose that TFA be classified as toxic to reproduction. Safety thresholds for TFA will probably fall, like they have for other PFAS, while dietary exposure is likely to increase in coming years as additional sources of TFA enter the environment and food systems.

So just how big is the PFAS problem?

TFA is just one aspect of the current PFAS problem. Thousands of tonnes of PFAS are emitted into the environment annually. There are some 23,000 known sites contaminated with PFAS in Europe. A further 21,000 are presumed to be contaminated. New sites are being discovered all the time.

This extent of the TFA and PFAS crisis is why I have said it threatens to exceed planetary boundaries. This means the planet at some point the planet won’t be able to cope with more, and permanent changes will result. Disturbances in the Earth’s homeostasis are clear at PFAS hotspots, and we don’t know what impact this will have in the long term.

Because PFAS are extremely mobile in the environment, the effect is global — and hard to reverse. PFAS produced today will exist in the plants and blood of animals for the entire future of this planet, as well as to the future generations of our grandchildren.

“Because PFAS are extremely mobile, the effect is global”

How do you propose we solve this PFAS crisis?

We have the tools to flatten the curve of TFA and other PFAS building up in the blood of future generations.

Three important measures are: one, we need to stop using PFAS and switch to PFAS- and TFA-free alternatives. That’s pretty straightforward. Many innovators are at the ready of solution, they just need the regulatory clarity and incentives to make this green economic transition. Two, there must be financial incentives to move away from the biggest sources of exposure. And three, TFA and other PFAS should be removed from active sources and hotspots, ideally under the polluter-pays principle.

An important point why preventative solutions are needed is that remediation technology, which is costly and ineffective, will not help if emissions continue. The cost of inaction will inevitably increase if PFAS continue to be produced. The only true way forward is to transition to society that stops using and emitting PFAS.