“Forever chemicals” in rainwater exceed safe levels


PFAS found in rain in Tibet

New research shows that rainwater in most locations on Earth contains levels of chemicals that “far exceed” safe levels.

These synthetic substances called PFAS are used in non-stick pans, firefighting foam and water-repellent clothing.

Called “forever chemicals”, they persist for years in the environment.

Such is their prevalence now that scientists say there is no safe place on Earth to avoid them.

Researchers from Stockholm University say it is “vitally important” to quickly curb the use of these substances.

Scientists fear that PFAS may pose health risks, including cancer, although research so far is inconclusive. In recent years there has been increasing concern about the proliferation of PFAS.

PFAS stands for poly- and perfluoroalkyl substances.

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, non-stick cookware, rain gear, glues, paper and paints.


Firefighting foams often contain PFAS chemicals

Safety concerns have also been raised regarding the presence of these long-lived substances in drinking water.

Earlier this year, a BBC investigation found PFAS in water samples in England at levels that exceeded European safety levels, but did not exceed the current safety level in England and Wales.

This new study, which looks at four specific chemicals in the category, suggests that levels of a PFAS in rainwater around the world often “far exceed” US drinking water advisory levels.

Soil around the world is similarly polluted, the data show.

The study’s findings lead the authors to conclude that a planetary boundary has been crossed—that there is simply no safe place on Earth to avoid these substances.

“We’re arguing here that we’re no longer in that safe operating space, because now we have these chemicals everywhere and these safety tips, we can’t achieve them anymore,” said lead author Professor Ian Cousins ​​from Stockholm University. .

“I’m not saying we’re all going to die from these effects. But we’re now in a place 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 certain conditions.

Many of these security levels in place are advisory, meaning they are not legally enforceable.

Other scientists believe that action on these chemicals should wait until the health risks are more clearly demonstrated.

Much research has been done on the health risks of PFAS, and scientists say that exposure to high levels may be associated with an increased risk of certain cancers, fertility issues and developmental delays in children.

However, such associations do not prove cause and effect, and other studies have found no link between PFAS and disease.

But for those who have spent years working closely with PFAS, the evidence in the new research paper underscores the need for a proactive approach.

“In this rainfall, the levels are higher than those environmental quality criteria already. This means that over time, we will have a statistically significant effect of these chemicals on human health,” said Professor Crispin Halsall from the University of Lancaster. . He did not engage in the Swedish study.

“And how will that play out? I’m not sure, but it will play out over time because we’re getting past concentrations that will cause some harm, because of people’s exposure to drinking water.”

Removal of the chemicals in the study from drinking water in treatment plants is possible, if expensive.


Rainwater around the planet exceeds US safety guidelines, scientists say

But getting below the US advisory levels is extremely difficult, according to the authors.

As scientists have gained more knowledge about PFAS over the past 20 years, the safety guidelines have been steadily reduced.

The same has happened with the presence of these chemicals in the soil – and this also causes problems.

In the Netherlands in 2018, the infrastructure ministry set new limits on PFAS concentrations in soil and dredged material.

But this caused the halt of 70% of building projects involving the removal of soil or the use of excavated material. After protests, the government relaxed the guidelines.

According to the new study, this type of relaxation of safety levels is likely to occur 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’re going to do the same thing with the US drinking water advisories because it’s impractical to implement.

“It’s not because there’s anything wrong with the risk assessment. It’s just because you can’t implement these things. It’s just impossible, financially, to implement any of these guidelines.”


A construction site in the Netherlands – many projects in the country had to stop due to restrictions on PFAS

The main challenge with these chemicals is their persistence, not their toxicity, the study authors say.

While some harmful PFASs were phased out by manufacturers two decades ago, they remain in water, air and soil.

One way PFAS circulates in the environment is in the form of tiny particles that are carried by sea spray into the air and then back to land.

This inability to break down in the environment means that PFASs are now even found in remote areas of Antarctica, as Professor Halsall recently reported.

While there are moves at European level to limit the uses of these chemicals and to find more benign substitutes, there are also hopes that industry will move quickly away from the use of PFAS.

“We need persistent chemicals and substances, we want our products to last as long as we use them,” Professor Cousins ​​said.

“And while there are conservative voices in the industry, there are also progressives. I’m very optimistic when I see these progressive industries working together.”

The research was published in the journal Environmental Science & Technology.

Follow Matt on Twitter @mattmcgrathbbc.

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