Cover News trainee reporter Ma Xiaoyu
At present, the world is polluted with multiple perfluorinated and polyfluoroalkyl substances (PFAS), which are also known as "permanent chemicals" and "toxic time bombs" because they are not easily degraded in the environment and the human body. PFAS has become the world's most concerned pollutant, and how individuals can prevent and control the impact of PFAS has become one of the most concerned issues for the public.
According to the "Capitol Hill" local time on the 5th, the new research report released by the US Geological Survey shows that at least 45% of tap water in the United States contains toxic perfluorinated and polyfluoroalkyl substances (PFAS).
However, this is not the first time PFAS has appeared in the public eye. According to the British "Guardian" reported on May 24, two British environmental public welfare organizations analyzed the public data of the British Environment Agency and found that 81% of rivers and lakes in England have toxic "permanent chemicals". Environmentalists have suggested that the UK government should ban the unnecessary use of PFAS in cosmetics, food packaging and other fields, and set safety standards to avoid the "chemical cocktail effect".
In addition, the Tokyo Metropolitan Government announced on July 5 that three leaks of foam extinguishing agents containing organic fluorine compounds occurred at the U.S. military's Yokota base in the Tama area of Tokyo between 2010 and 2012. A blood test released in June showed higher concentrations of PFAS in the blood of local residents. The petition from the Liaison Council states that many Tokyo residents are concerned about the health effects of PFAS and that it is necessary to address this anxiety as soon as possible.
Yokota Air Base
"Permanent chemicals" PFAS are everywhere around you
According to the data, PFAS includes PFOS and PFO, which are widely used in plastic processing and manufacturing processes, especially fluoroplastics and high-performance engineering plastics. Because PFAS are widely used, long-acting chemicals, they are difficult to degrade, accumulate in the environment and the human body, and are often referred to as "permanent chemicals."
PFAS can be found in water, soil, air, and food, as well as materials in homes or workplaces, including drinking water, soil and water in or near waste sites, landfills, disposal sites, and hazardous waste sites, fire fighting foams, electronics, and certain textile and paper manufacturers, food packaging, household products and dust, personal care products, etc. And can accumulate over time in people, animals and the environment.
U.S. peer-reviewed scientific studies have shown that exposure to certain levels of PFAS may be associated with effects such as reduced fertility in pregnant women, delayed childhood development, increased risk of cancer, decreased immunity, interference with the body's natural hormones, and increased risk of obesity. Previous studies have found that some PFAS are associated with serious health problems.
How should PFAS, which is restricted by many countries, be governed?
EPA Administrator Michael Reagan has said that "communities in this country have long been affected by the threat of PFAS pollution." That's why President Biden initiated a whole-of-government approach to these harmful chemicals, and the EPA is leading the way."
In December 2022, Mike Roman, Chairman and CEO of American Industries, announced that he would retire from the production of per- and polyfluoroalkyl substances (PFAS) and work to end the use of PFAS in his portfolio by the end of 2025.
In February, the EPA announced $200 million from President Biden's bipartisan infrastructure law to address contaminants in drinking water nationwide and expand PFAS monitoring in drinking water. In April, the Biden-Harris administration proposed the first national standard to protect communities from PFAS in drinking water.
According to the official website of the Ministry of Ecology and Environment, the "List of New Pollutants under Key Control" implemented by the mainland on March 1 this year includes perfluorooctane sulfonic acid and its salts and perfluorooctane sulfonyl fluoride (PFOS), perfluorooctanoic acid and its salts and related compounds (PFOA), perfluorohexyl sulfonic acid and its salts and related compounds (PFHxS). All three categories of pollutants are listed under the Stockholm Convention on Persistent Organic Pollutants and have been banned internationally except for exempted uses.
List of New Pollutants under Key Control
At present, countries have begun to issue bans on the outflow of PFAS products, so how can the pollution caused by PFAS be effectively controlled? Deng Shubo, a professor at Tsinghua University and a member of the POPS Special Committee of the Chinese Society of Environmental Sciences, once said in an interview with China Environment News that among the many technologies for removing PFAS in water, adsorption technology is the most practical and commonly used technology, which can remove PFAS while removing traditional pollutants. However, PFAS are usually removed from water, and the treatment cost is high.
According to the data, semi-permeable membrane treatment processes such as reverse osmosis and nanofiltration (NF) have been shown to be effective in removing PFAS, but there are still major problems in the treatment of concentrates containing PFAS.
According to a new study in the journal Water Research, PFAS removal efficiency in NF concentrates can be achieved by 90% using the new technology Foam fractionation (FF). The researchers also added cationic cosurfactants to the FF process to improve the removal efficiency of short-chain PFAS by 94%. Among them, the removal efficiency of PFPeA was 37%, PFHxA was 9%, and the removal efficiency of PFBS was 34%, respectively.
Individuals may be able to reduce the impact through a fiber-rich diet
So based on the long-term harm of PFAS, how can individuals prevent it? The University of Kentucky seems to have a viable approach. Its researchers say a fiber-rich diet can reduce the risk of disease associated with exposure to perfluorooctane sulfonate (PFOS), counteracting the adverse health effects of environmental pollutants.
According to information released in April this year, Dr. Pan Deng of the SRP Center at the University of Kentucky led a team to study the effects of different fibers (including inulin and pectin, another soluble fiber) on the liver and gut health destruction induced by PFOS in mice.
The results showed that inulin and pectin-fed mice were less susceptible to metabolic outcomes of PFOS exposure, such as liver damage and lipid accumulation, compared to mice fed a standard diet. Mice fed soluble fiber also had lower levels of PFOS in plasma and liver, and had higher gene expression, preventing PFOS-induced atherosclerosis or fat accumulation in and on arterial walls.
Project leader Dr Bernhard Hennig said more research is needed in the future to understand the exact mechanisms involved in the preventive properties of dietary fiber for environmental damage. The team next plans to further understand how positive lifestyle changes, such as healthy nutrition and increased physical activity, will alter the disease risk mechanisms associated with PFAS exposure.
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