Forever Chemicals
So here’s the situation.
You’ve probably heard of PCB’s. They were banned because of the widespread and persistent contamination in people and animals since they began to be used in the 1960’s, found as far as the polar regions. Then there’s also DDT, an insecticide to have detrimental effects on wildlife and their reproduction, which was also eventually banned in 1986 in the UK. These both come under something known as POP’s i.e., persistent organic pollutants.
A list of 12 POPs known as the “dirty dozen” – including PCBs and DDT – were banned in 2004 by an international treaty known as the ‘Stockholm Convention’, and more chemicals have been added since. To date, 185 parties have signed the treaty, promising to implement control measures on these pollutants.
Unfortaunely our toxic contamination of the planet hasn’t seemed to have stopped there.
PFAS (Per- and poly- fluoroalkyl substances) are a highly persistent group of several thousand chemicals. They can be found in food packaging, cosmetics, cookware, waterproof clothing, carpets, mattresses, electronics and fire-fighting foams.
PFAS have a wide variety of properties. They can make products waterproof, stain-resistant and grease-proof, and can withstand a lot of heat. They're also very unreactive, so their strong bonds mean they don't break down easily aka they don’t biodegrade so they stay in the environment. This means they don’t break down in the environment, hence their nickname, forever chemicals.
PFAS are also able to move in water very easily. They have been found in rivers, seawater and even drinking water as water treatment plants are currently unable to effectively remove them. Once in the sea they have to ability to build up in the fatty tissue of marine animals if ingested. Once in the food chain, these chemicals can “biomagnify” as they pass from prey to hunter, reaching higher concentrations in top predators.
Alongside this terrible effect, the climate crisis may play a role also, by speeding up the movement of these forever chemicals around the planet.
As temperatures rise, POPs will evaporate even more easily into the atmosphere. In the future, this “grasshopper effect”, by which pollutants evaporate in warmer regions and travel in air currents to cooler places, could have an even greater impact on people, animals and places thousands of miles away from the source of pollution. So the issue is: it’s not as simple as one would think to just ‘go collect them up and get rid of them’ …
So what’s being done?
A lot of action comes down to policy and legislation, as we’ve seen in the history of chemicals.
The Stockholm Convention mentioned earlier calls for PCBs to be phased out in equipment by 2025 and all PCBs to be eliminated by 2028. So far the treaty has not succeeded in turning off the tap for much of this toxic pollution. Only 17% of the total amount of PCBs has been eliminated worldwide, with 83% (14m tonnes) still to be dealt with, according to the UN Environment Programme. An estimated 1m tonnes of PCB-contaminated material are waiting to be destroyed in Europe alone.
For PFAS, PFOS and PFOA have already been banned or restricted because of their toxic, persistent and bioaccumulative effects, but there are concerns about others on which there is less toxicity evidence available because they have been less studied.
Countries that are partners to the Stockholm Convention agreed on 17th June 2022 to add PFHxS (which is in the family of PFAS), its salts, and related compounds to a list of compounds they pledge to eliminate in the Convention. PFHxS is just one in the group that has been widely detected in human blood and found in drinking water supplies.
Though this is great to see their elimination in use, we are talking about a large group of chemicals, so regulating by a chemical-by-chemical approach is taking far too long. As stated by Sara Brosché, science advisor to the International Pollutants Elimination Network:
“PFHxS elimination “is an important step towards banning more of these toxic ‘forever chemicals’ that pollute the environment and humans all over the world, threatening the health of millions of people. But the chemicals industry keeps replacing banned PFAS with different but equally harmful PFAS. That’s why there is an urgent need to ban all PFAS rather than addressing them one by one.””
What’s the future of forever chemicals?
The threat of persistent chemicals is not new. PCBs continue to wreak havoc decades after they were banned. The only option to prevent PFAS pollution in the environment is to stop them at source. We must act now to prevent PFAS leaving a similar, if not worse, legacy to PCBs for future generations.
PFAS exposure has been linked to impacts on the immune function of sea otters, neurological impacts in polar bears as well as negative effects on fish and seabirds. Exposure to humans has been associated with decreased thyroid hormone levels, adverse effects on development, and liver problems.
These are not isolated incidents and chemical pollution has already been revealed to be one of the main drivers of the current biodiversity crisis.
Work is underway in the US looking into ways to remove them from the environment as well as ways to destroy or decontaminate POPs. The most effective way to get rid of POP’s is by incineration at extremely high temperatures, an expensive and sometimes logistically impossible process.
In Europe, Germany, Denmark, the Netherlands, Norway and Sweden have signalled their intention to ban the manufacture of PFAS, most of their uses and their placement on the EU market this year.
So work is being done, whether it’ll be fast enough we don’t know. We need to speak louder, get the information out there to hopefully speed up this process. But this is a great start, and hopefully we see an integration of all PFAS into the Stockholm Convention to be banned soon and in time, eliminated from the environment.
