[Translation] Rainwater around the world is too toxic to drink, study finds

Author: Becky Ferreira

Original: Rainwater Everywhere Now Considered Too Toxic for Safe Consumption, Study Finds

Originally posted: https://www.vice.com/en/article/m7gban/rainwater-everywhere-now-considered-too-toxic-for-safe-consumption-study-finds

Scientists say there are very high levels of "permanent chemicals" in the atmosphere, and according to safety guidelines, rainwater around the world contains toxic substances that are unsafe for humans to drink for a long time.

Hazardous pollutants called perfluorinated and polyfluoroalkyl substances (PFAS) are so high in the environment around the world that scientists believe the ubiquitous pollutant has exceeded Earth's safe boundaries. PFAS are also known as "permanent chemicals" because they break down very slowly.

These chemicals are in the air we breathe, in the water we drink, in the rainwater in our communities, and even in our blood. PFAS pollution is known to affect our immune system, but the full impact on human and ecological health is unknown.

Given the unknowns about this pollution, scientists led by Ian Cousins, a professor of environmental studies at Stockholm University, conducted field tests on four PFASs and analyzed countless other measurements. The team, which published the findings in the recent issue of Environmental Science & Technology, warned: "Even in remote and sparsely populated areas, such as Antarctica and the Tibetan Plateau, the strictest PFAS guidelines are exceeded. standard."

Of course part of this has to do with the guidelines for developing PFAS standards. As evidence of the negative effects of PFAS has grown, many countries have significantly lowered PFAS standards. For example, the US Environmental Protection Agency (EPA) recently issued a guideline for healthy drinking water for a carcinogen PFA that is 1/37.5 millionth of the old standard.

"Initially, we thought people lived in areas that were polluted and therefore not meeting the guidelines," Cousins said in an email. "We were surprised by the low lifetime intake values for PFOS and PFOA in the EPA's newly published drinking water health recommendations. Our report was not finalized when the new values were published."

A major finding of the study, Cousins added, is that rainfall around the world exceeds these standards.

For this reason, the researchers concluded that PFAS pollution has crossed an atmospheric boundary. According to the team that first introduced the concept in 2009, it's the limit of "maintaining a safe operating space for humans with the Earth's system functioning properly." Boundaries are broken when anthropogenic pressure causes irreversible damage to Earth's ecosystems and to our own well-being.

"Based on a study of four perfluoroalkanoic acids (PFAAs), we concluded that in many human-inhabited regions, PFAAS have exceeded atmospheric boundaries, contaminating media such as rainwater, surface water and soil," the researchers said. The level of contamination exceeds the standards of the new guidelines."

"We can therefore conclude that the global diffusion of these four PFAAs in the atmosphere has led to the transgression of chemically polluted Earth's boundaries," they added.

Beginning in the 1940s, manufacturers developed thousands of different PFASs for products such as nonstick cookware, stain-resistant fabrics, and waterproof clothing. The strong molecular bonds that make PFAS commercially useful, once a pollutant that seeps into the water cycle, can cause endless trouble.

The dangers of PFAS have been known for decades, which is why most manufacturers in most countries, except China, have stopped producing PFAS. However, Cousins and his colleagues found that the four PFAS they tracked did not disappear significantly because they were so persistent.

"The four substances we studied have been phased out for some time (with the exception of China)," Cousins said. "They (and the so-called precursors that degrade into these four substances) circulate between the Earth's surface and the atmosphere. There is little going on. production or use. These four PFASs are extremely persistent, so they remain in the environment and continue to circulate (mainly in the hydrosphere) even if primary emissions are stopped.”

While there are cleaning technologies that can help remove these chemicals, they are expensive and do not filter out sufficient amounts of PFAS to meet new safety standards.

"These technologies can be used to clean drinking water, wastewater or contaminated soil, but as far as I know, the level of cleanliness falls short of the EPA guidelines," Cousins said. "The new regulations are also barely measurable."

"There's nothing we can do but ask China to stop producing and consuming the four PFASs in this study," Cousins said.

He concluded: “They will slowly dilute into the deep sea. We can also prevent leaching of old landfills (by sealing landfills and treating leachate) and ensure that old waste is incinerated at high temperatures. As for other PFAS, only in Use them only when absolutely necessary. Or replace PFAS with safe, sustainable alternatives.”

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