- According to the study, rainwater all over the Earth contains “perpetual chemicals” that are unsafe to drink.
- Per- and polyfluoroalkyl substances (PFAS), linked to cancer, enter homes and the environment.
- Researchers say PFAS levels across the planet are dangerous and the substances should be limited.
According to a group of environmental scientists, rainwater is no longer drinkable anywhere on Earth under US pollution regulations.
That’s because rainwater around the planet now contains dangerous chemicals called per- and polyfluoroalkyl substances (PFAS). In a paper published in the journal Environmental Science & Technology on August 2, researchers at Stockholm University, who have been studying PFAS for a decade, found evidence that the substances have spread throughout the atmosphere, leaving no place untouched.
There are thousands of PFASs, all man-made, used in food packaging, water-repellent clothing, furniture, carpets, non-stick coatings for pots and pans, fire-fighting foam, electronics, and some shampoos and cosmetics. They may be released into the air during manufacturing and daily use. They are also washed into ocean water and become sea spray aerosol. From there, they spread through the atmosphere and fall back to Earth during rain.
They are often called “perpetual chemicals” because they persist for long periods of time without breaking down, allowing them to accumulate in humans, animals, and the environment.
PFAS have been found in Antarctica and in Arctic sea ice. Their prevalence on the planet poses a threat to human health, as peer-reviewed studies link them to some cancers, reduced fertility, reduced vaccine response, high cholesterol, and developmental delays in children.
Like microplastics, it is difficult to determine all the long-term health effects of PFAS exposure because they contain so many different compounds and are so widespread in the environment. A new paper suggests that everyone on Earth is at risk.
According to EPA restrictions, “rainwater will be deemed unsafe for drinking everywhere”
Perhaps the best known of these substances are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). In June, based on new data on health effects, the Environmental Protection Agency significantly tightened its guidelines for how much PFOA and PFOS can be safely present in drinking water.
The EPA previously set the acceptable level for both substances at 70 parts per trillion. The new guidelines cut that by a factor of 17,000, limiting safe levels to 0.004 parts per trillion for PFOA and 0.02 parts per trillion for PFOS.
Stockholm University researchers assessed the levels of PFOA, PFOS and two other PFASs in rainwater and soil around the planet and compared them to regulatory limits. Levels of both substances in rainwater “often significantly exceed” EPA limits, the study authors concluded.
“Under the latest U.S. guidelines for PFOA in drinking water, rainwater everywhere will be deemed unsafe for drinking,” Ian Cousins, lead author of the study and a professor in Stockholm University’s Department of Environmental Sciences, said in a press release.
“Although in the industrialized world we don’t often drink rainwater [directly]many people around the world expect it to be safe to drink, and it supplies many of our drinking water sources,” Cousins added.
The paper also found that soil around the world is “pervasively contaminated” with PFAS. Because PFAS persist for so long and circulate so efficiently through the planet’s oceans, atmosphere, and soil, researchers expect levels to continue to be dangerously high.
Ultimately, the researchers concluded that PFAS exceeded a safe “planetary limit” for human health.
“It is vital that the use and release of PFASs be rapidly limited,” they wrote.