You can find per- and polyfluorinated substances (PFAS) in drinking water, cookware, food packaging and many other sources. They are called forever chemicals for a reason — the strong carbon-fluorine links characterizing this group of over 9,000 molecules are virtually unbreakable, which is why they are so good at waterproofing coats and making makeup shiny. They can also cause serious health problems. Now, University of British Columbia engineers are working toward a solution.
How common are PFAS in drinking water?
Scientists invented PFAS in the 1930s, and since then, these chemicals have made their way into drinking water worldwide. Rivers, lakes, groundwater, wells and tap water often contain the chemicals. PFAS can take centuries to break down in the environment.
Although many people are concerned about PFAS in drinking water, you likely interact with them whenever you order takeout, use cleaning products or even floss your teeth. Almost every person in the world has some level of PFAS in their blood because the chemicals are ubiquitous in modern life. However, that does not mean they are safe for human consumption.
In 2023, the University of British Columbia (UBC) began piloting real-world tests of a new water treatment method. The team developed a filter that removes long- and short-chain PFAS and captures them inside porous beads. The beads are potentially recyclable or reusable in other filters, including those in homes, municipal centers and industrial sites.
Additionally, the team created new methods for breaking down the leftover PFAS and rendering them harmless. Destroying PFAS is crucial in preventing them from ending up in the environment. Existing methods for filtering PFAS usually create byproducts containing high levels of the chemicals. Waste workers then incinerate the compounds at high temperatures — since burning them does not destroy their molecular bonds — or dump them in landfills, neither of which is a sustainable solution. At worst, filters simply divert PFAS back into waterways after filtering them out of homes.
Which filters currently remove PFAS?
A few devices adequately filter out PFAS and other chemicals from the water supply. They include:
Reverse osmosis filters
Reverse osmosis filters are a type of high-pressure membrane and are the most expensive technology for removing PFAS. They push high-pressure water through a membrane with tiny pores to separate the molecules from water. These filters are effective against short-chain PFAS.
Unfortunately, reverse osmosis requires a large volume of water. It also discharges PFAS-contaminated water back into septic or sewer systems, which can reintroduce the chemicals into the environment.
Granular activated carbon filters
Granular activated carbon systems are the least expensive option. They bind long-chain PFAS — such as PFOA and PFOS, which cause several health problems — to a porous carbon surface.
You can use a granular activated carbon filter on faucets, sinks, refrigerators, pitchers and household units that filter water for the entire house. These filters are only effective against long-chain PFAS.
Ion exchange resins
These devices act like magnets that attract PFAS particles. Some types remove up to 100% of PFAS in drinking water. Ion exchange resins contain highly porous, polymeric material insoluble to acids, bases and water. Positively charged anion exchange resins (AER) can remove negatively charged chemicals.
These systems are effective at trapping short-chain PFAS and typically work better than activated carbon filters. However, you eventually have to replace the resin.
A nanofiltration device is another type of high-pressure membrane filter. Unlike reverse osmosis filters, which remove salts and other minerals from the water, nanofiltration systems allow sodium chloride to pass through. The pores on a nanofiltration membrane are not as tight as those on a reverse osmosis filter.
Nanofiltration and reverse osmosis filters effectively remove a wide range of PFAS from drinking water. However, they leave the PFAS intact to pass on into another water system, ultimately contaminating the environment. This technology is best suited for homeowners since it is easier to dispose of a small stream of PFAS-contaminated water than on an industrial scale.
How do PFAS affect human health?
There are thousands of PFAS, and scientists have yet to determine how each affects the human body. However, some are well known for their adverse effects on people’s health.
PFOA and PFOS are human carcinogens that disrupt the endocrine system. The body readily absorbs these chemicals but takes years to eliminate them. Known health problems associated with these PFAS include harmful effects on the thyroid and liver, cancer, and harm to developing fetuses.
The main route of exposure for PFOA and PFOS is through ingestion. Over 40% of U.S. drinking water comes from groundwater, and it is common to find these PFAS near airfields, landfills and industrial sites.
The effects of exposure to other PFAS are unclear. However, evidence suggests that high levels of certain PFAS may cause kidney and testicular cancer, high blood pressure or pre-eclampsia in pregnant women, a decreased vaccine response in children, lower infant birth weights, changes in liver enzymes and increased cholesterol levels. PFAS have also caused delayed development and newborn deaths in lab animals.
Conducting human trials involving deliberate PFAS exposure would be unethical. Therefore, it is hard to draw direct conclusions about how these chemicals affect the body. Researchers must look at correlations between PFAS levels in the blood and the development of health problems over time.
Regulating PFAS pollution
Filtering out and destroying existing PFAS in drinking water is a great step toward a cleaner world, but what if companies stopped manufacturing them in the first place?
In 2023, the U.S. Environmental Protection Agency (EPA) proposed nonenforceable maximum contaminant level goals (MCLGs) and enforceable maximum contaminant levels (MCLs) for six PFAS chemicals. This decision comes during growing discontent with PFAS in drinking water, packaging and industrial sources.
Many countries and U.S. states have banned certain PFAS, and some manufacturers have stopped producing them. The new EPA rules should make it even harder to manufacture and dispose of certain PFAS. However, businesses often skirt regulations by replacing a discontinued PFA chemical with a new type that has unknown health effects.
Dupont agreed to phase out a PFAS chemical called C8 in 2015. However, the corporation introduced a new chemical called GenX — no relation to the generation with the same name — to replace C8. It also created a spinoff company called Chemours to manufacture it in North Carolina.
Today, GenX permeates the Cape Fear River, and its effects on human health are still unknown.
New regulations should be more stringent to prevent companies from switching from one PFA chemical to another. A blanket ban might be the only way to enforce that, and although it would be expensive, and some products might lose their luster, it could profoundly benefit human health.
Fighting back against PFAS
Forever chemicals do not have to be forever. Although these insidious substances seem to permeate every sphere of modern life, new technological breakthroughs are getting the world close to a solution for filtering and destroying them.
Better yet, new regulations are forcing companies to phase some of them out altogether. Time will tell if a complete ban on PFAS is feasible, but in the meantime, focusing on removing them from water is a good place to start.