They are in makeup, dental floss and menstrual products. They come in nonstick pans and takeout food wraps. Same with rain jackets and firefighting equipment, as well as pesticides and artificial turf on sports fields.
These are PFAS: a class of man-made chemicals called per- and polyfluoroalkyl substances. They are also called “forever chemicals” because the bonds in their chemical compounds are so strong that they do not break down for hundreds to thousands of years, if at all.
They are also in our water.
A new study of more than 45,000 water samples worldwide found that about 31 percent of the groundwater samples tested that were not near any obvious source of contamination had levels of PFAS considered that is harmful to human health by the Environmental Protection Agency.
About 16 percent of the surface water samples tested, which were also not near any known source, had similarly dangerous levels of PFAS.
This finding “sets off alarm bells,” said Denis O’Carroll, a professor of civil and environmental engineering at the University of New South Wales and one of the study’s authors, who published Monday in Nature Geoscience. “Not just for PFAS, but also for all the other chemicals we put into the environment. We don’t know their long-term effects on us or the ecosystem.”
High level of Exposure to some PFAS chemicals has been linked in higher cholesterol, damage to the liver and immune system, hypertension and pre-eclampsia during pregnancy, as well as kidney and testicular cancer.
The EPA has proposed strict new drinking water limits for six types of PFAS and could announce its final rule as early as this week.
For their research, Dr. O’Carroll and his colleagues compiled nearly 300 previously published studies on PFAS in the environment. Together, these studies included 12,000 samples from surface water — streams, rivers, lakes and ponds — and 33,900 samples from groundwater wells, collected over the past 20 years. These samples do not cover the entire planet: they are concentrated in areas with more environmental researchers, such as the United States, Canada, Europe, Australia and the Pacific Coast of Asia.
The samples were likely concentrated in areas where people are already concerned about PFAS contamination, said Dr. O’Carroll. He warned that, as a result, the findings of this new study could be skewed to show higher levels of contamination than a true global average. There is reason to believe, however, that there is some level of PFAS contamination almost everywhere on the planet, he said.
Among the countries where the studies were done, the United States and Australia had particularly high concentrations of PFAS in their water samples.
Among the available samples, the highest levels of contamination were typically found near places like airports and military bases, which regularly use PFAS-containing foam to practice firefighting. About 60 to 70 percent of both groundwater and surface water samples near these types of facilities have PFAS levels in excess of EPA Hazard Indexwhich measures how dangerous mixtures of certain chemicals are to human health, and also exceeds the limits in the EPA’s proposed new drinking water regulations.
This research does an impressive job of collecting available data and highlighting the extent of global contamination from PFAS chemicals, said David Andrews, a senior scientist at the Environmental Working Group, an organization of research and advocacy not involved in this study.
Scientific research on the health effects of PFAS has changed dramatically in the past 10 to 20 years, he said, and what are considered safe exposure levels today are a fraction of what they were decades ago. ago
The proposed EPA drinking water rules, depending on their final language, would be a big step forward, he said.
Michael Regan, the EPA administrator, said his agency intends to require utilities to treat their water so that levels of some PFASs are close to zero. This requirement would make the United States one of the strictest countries in terms of regulating PFAS in water.
Dr. added. Andrews, however, that while treating drinking water is important, it won’t solve the entire problem. His own research has shown that PFAS chemicals are also prevalent in wildlife.
“Once they’re released into the environment, it’s incredibly difficult to clean them up, if not impossible in many cases,” he said. “They can be removed from drinking water, but the ultimate solution is not to use them in the first place, especially in areas where there are clear alternatives.”
For example, some outdoor clothing brands are moving away from PFAS for waterproofing their products and toward alternatives such as silicones. Fast food restaurants may wrap their burgers in heat-treated paper to make them resistant to grease, or coated with PFAS-free plastic instead. The Department of Defense is beginning to replace traditional firefighting foam with an alternative called fluorine-free foam, or F3.
Meanwhile, said Dr. O’Carroll, “I’m not in any way trying to say that we shouldn’t drink water.
It’s more that I’m trying to say, from a societal point of view, we need to be careful what we put into the environment.”
