New research shows that rainwater in most places on Earth contains levels of chemicals that “far exceed” safe levels.
These synthetic substances — poly and perfluoroalkyl, known by their acronym PFAS — are used in products such as non-stick cookware, firefighting foam and waterproof clothing.
Dubbed the “eternal chemicals”, they persist for years in the environment.
Such is their prevalence now that scientists say there is no longer any place on Earth to avoid them.
Stockholm University researchers say it is “of vital importance” that the use of these substances is quickly restricted.
Scientists fear that PFAS could pose health risks, including cancer, although research so far has been inconclusive. They are increasingly concerned about the proliferation of PFAS in recent years.
There are about 4,500 of these fluorine-based compounds and they are found in nearly every home on Earth in hundreds of everyday products, including food packaging, raincoats, adhesives, paper and paints.
Safety concerns about the presence of these long-lasting substances in drinking water were also raised.
Risks still uncertain
Earlier this year, a BBC investigation found PFAS in water samples in England at levels that exceeded European safe levels, but did not exceed the current safe level in England and Wales.
New research published in the journal Environmental Science & Technology analyzes four class-specific chemicals and indicates that levels of the substances in rainwater around the world often “far exceed” recommended levels for US drinking water.
Soil around the world is similarly contaminated, evidence suggests.
The study’s findings lead the authors to conclude that a planetary boundary has been crossed — there is simply no safe space on Earth to avoid these substances.
“We argue here that we are no longer within that safe space, because now we have these chemicals everywhere,” said Professor Ian Cousins, lead author of the study done at Stockholm University.
“I’m not saying we’re all going to die from these effects. But we’re at a point where you can’t live anywhere on the planet and be sure the environment is safe.”
While this is undoubtedly cause for concern, there are some caveats.
Many of these security levels in place are advisory, meaning they are not legally enforceable.
Other scientists consider that action against these chemicals should not be taken until the health risks are more clearly proven.
Much research has been done on the health risks posed by PFAS, and scientists say exposure to high levels may be associated with an increased risk of some cancers, fertility problems, and developmental delays in children.
However, such associations do not prove cause and effect, and other studies have found no connection between PFAS and disease.
But for those who spent years working in roles that brought them into contact with PFAS, the evidence in the new research paper underlines the need for a precautionary approach.
“In the rain, the levels are already higher than the environmental quality criteria. This means that over time we will have a statistically significant impact of these chemicals on human health,” said Crispin Halsall of Lancaster University. He is not involved with the Swedish study.
“And how will that manifest? I’m not sure, but we’ll see over time, because we’re exceeding concentrations that are going to cause some harm, because of the exposure of humans in their drinking water.”
Removal of study chemicals from drinking water in treatment plants is possible, albeit expensive.
But staying below US counseling levels is extremely challenging, according to the authors.
As scientists have gained more knowledge about PFAS over the past 20 years, safety warnings have been continually reduced.
So has the presence of these chemicals in the soil – and that’s causing problems too.
economic pressure
In the Netherlands, in 2018, the Ministry of Infrastructure set new limits for PFAS concentrations in soil and dredging material.
But this caused 70% of construction projects involving soil removal or use of excavated material to be stopped. After protests, the government relaxed the guidelines.
According to the new study, this kind of relaxation of safety levels is likely to happen with water contamination as well.
“If you applied these guidelines everywhere, you wouldn’t be able to build anywhere,” said Professor Ian Cousins.
“I think they’ll do the same thing with US drinking water warnings, because they’re not practical to enforce. It’s not because there’s anything wrong with the risk assessment. It’s just because you can’t enforce these things. It’s just impossible, from an economic point of view, apply any of these guidelines.”
The main challenge with these chemicals is their persistence, not their toxicity, say the study authors.
Although some harmful PFAS were phased out by manufacturers two decades ago, they persist in water, air, and soil.
One way PFAS travel through the environment is in the form of small particles transported in spray from the sea to the air and then back to land.
This inability to break down in the environment means that PFAS are now found even in remote areas of Antarctica, as reported by Halsall recently.
While there are European-wide moves to restrict the use of these chemicals and find more benign substitutes, there are also hopes that the industry will quickly move away from the use of PFAS.
“We need persistent chemicals and substances, we want our products to last a long time while we use them,” said Professor Cousins.
“And while there are conservative voices in the industry, there are also progressive actors. It makes me very optimistic when I see these progressive industries working together.”
This text was published on the BBC News Brazil website.
