Report and Revised Risk Management Scope . The two reports document the ubiquity of PFAS (also known as "forever chemicals"), the threats they pose to humans and wildlife, and proposed actions to reduce exposure.
The environmental and clinical threats from microplastics, which include many PFAS , are significant, as numerous previous studies have shown. More recent studies are equally concerning.
On September 16, JAMA Network Open published online a case series showing that microplastics were found in the olfactory bulbs of eight deceased individuals, suggesting that the olfactory pathway is a potential entry route for microplastics into the brain.
On September 17, a study published online in Nature' s Journal of Exposure Science & Environmental Epidemiology documented evidence that 3601 chemicals that leach into food during storage, processing, and packaging end up in the human body, 80 of which entail known serious health risks.
Dozens of companies have geared up to eliminate PFAS from landfills, water systems, and products known to leach into the bloodstream of humans, pets, and wildlife in Canada and globally, using an array of technologies in various stages of development. One such company, a University of British Columbia (UBC) spin-off called ReAct Materials, Vancouver, British Columbia, Canada, recently showed that its novel system for trapping and destroying PFAS can be used effectively to clean up municipal water systems and undertake industrial projects such as waste stream cleanup.
Will these efforts in Canada and elsewhere solve the problem? Maybe.
"In Canada, there are guidelines for acceptable levels of PFAS, but there is no regulation saying that something has to be done if levels aren't acceptable," Johan Foster, PhD, an associate professor of chemical and biological engineering at the University of British Columbia in Vancouver, told Medscape Medical News . Foster is a cofounder of ReAct Materials with Raphaell Moreira, PhD, a professor at Universität Bremen in Bremen, Germany.
What Are PFAS?
PFAS are a class of thousands of substances used as surfactants, lubricants, and repellents for dirt, water, and grease, according to Canada's health information on the substances. PFAS are used in firefighting foams, food packaging, drugs, cosmetics, sunscreens, pesticides, carpets, furniture, clothing, cars, trucks, and electronics products, among others.
PFAS releases from municipal solid waste (MSW) landfills, MSW incineration, composting of PFAS-containing food packaging, wastewater treatment systems, and the application of biosolids to land are potential pathways of PFAS exposure to the environment and humans.
In short, PFAS are just about everywhere. Part of the reason is that they impart desirable characteristics, such as waterproofing, to products that people use daily. Indeed, one recent study identified more than 200 use categories and subcategories for more than 1400 individual PFAS, including not only the well-known categories mentioned above but also products as diverse as ammunition, climbing ropes, guitar strings, and artificial turf.
PFAS also are used as coatings on many products, said Foster. An example is men's slacks. One television commercial showed a man pouring coffee all over his pants, and the coffee just ran right off, thanks to a perfluorinated coating. "On one side, they're fantastic molecules that work very well for what they do, like waterproofing. The problem is they last forever. And the other problem is they get into the human body and cause problems."
Among the problems facing those who want to get rid of these substances are that people are accustomed to them and it's difficult to find replacements, Moreira told Medscape Medical News . "We now face two challenges: How to destroy the PFAS that are already out there and how to create things to replace them." Other hydrophobic coatings are not as effective as PFAS, he said. And there are no replacements for products such as fire extinguishers.
"As a society, we need to accept the fact that these things maybe shouldn't last forever, especially when we're looking at sustainability and a green economy," said Moreira. "We can't use these forever chemicals and have something that's biodegradable. The two are mutually exclusive."
Clinical Consequences
While governments, organizations, and individuals seek acceptable replacements for PFAS, exposures continue, with potentially dire consequences for human health. "Studies across the globe show that PFAS exposures may increase the risk for thyroid disease, high cholesterol, high blood pressure, diabetes and steatotic liver disease, and kidney and testicular cancer , and may also reduce fertility in females and males," Dania Valvi, MD, PhD, an associate professor and codirector of the MS in Epidemiology program at the Icahn School of Medicine at Mount Sinai in New York City, told Medscape Medical News
"Of particular concern are exposures occurring in pregnancy and early life, as PFAS can pass through the placenta and later via breast milk from the mother to the child, increasing the risk of newborns' developing severe chronic diseases in later life," she said. "PFAS may also affect the immune system and have also been linked with reduced response to vaccinations in children."
"We know that PFAS can start to cause clinical problems at very, very small amounts — nanograms per liter of water," Foster added. For example, an amount equivalent to half of a small wooden toothpick would contaminate an Olympic-sized swimming pool. "That translates into about 20 nanograms of PFAS contaminating 2.5 million liters of water."
Adsorb and Destroy
Two classes of technologies are in development to help rid the environment of PFAS: Those that adsorb the PFAS and those that destroy them, Foster explained. Adsorption technologies can pull PFAS out of products and break them down, but the problem then is what to do with them. "If you throw them out, they end up in a landfill, and eventually they're going to get back into the water. So, you're just kicking the can down the road."
Many of the destruction technologies are not scalable or practical, he said. For example, one approach uses activated carbon, which adsorbs PFAS. The carbon can be regenerated by heating it to 300 °C, but this approach doesn't destroy the PFAS; it evaporates them. "You do end up with pure activated carbon in the end, but the PFAS are in the atmosphere. That's why we're finding them in glaciers, mountain lakes, killer whales, and, of course, humans."
While many of the current technologies can only adsorb, while others are designed to destroy PFAS, the UBC system combines an activated carbon filter with a patented catalyst that enables it to capture and trap the PFAS before breaking them down into harmless components on the filter material, Foster explained.
To treat water, he said, "We can put huge volumes of water through the catalyst, and it will adsorb the PFAS and destroy it in a quick two-step process." The team is trying to scale the system up with smaller units to treat single or multihost water systems, then expand into municipalities.
"These technological advances are important, but their cost-effectiveness at larger scales is still unclear," Valvi noted. "The most effective way to get rid of PFAS in the environment is to limit the production and uses of PFAS in the first place."
Reducing Exposure
The Canadian government is proposing a phased approach to do just that, starting with a regulation to restrict PFAS not already regulated in firefighting foams, followed by additional measures to prohibit other uses or sectors in relation to PFAS, according to an announcement of the recent PFAS draft update and risk management scope.
"Moreover," the announcement continued, "the government plans to publish the final version of the updated Prohibition of Certain Toxic Substances this fall 2024 to further restrict the manufacture, use, sale, offer for sale, and import of the three PFAS subgroups that are already regulated: Perfluorooctane sulfonate, perfluorooctanoic acid, and long-chain perfluorocarboxylic acids."
In addition, the government aims to take action to reduce exposures from PFAS at known federal contamination sites, which could include providing alternative drinking water sources, installing water treatment systems, implementing food consumption advisories, remediating specific areas of the sites to remove PFAS hot spots or source areas, and long-term monitoring to determine adherence to developed guidelines and screening values.
For individuals, Valvi advises, "we can use a certified water filter that removes PFAS in our home and workplace; limit the consumption of take-out and fast foods because many food containers are PFAS-coated; replace our nonstick cookware with stainless steel; and avoid products labeled as stain-resistant and water-resistant, such as clothing and furniture because many of these products contain PFAS."
As there is growing awareness of PFAS health risks, patients who suspect they have been exposed to PFAS through public water systems or other sources will almost certainly raise this issue more often with their healthcare providers, seeking guidance, she added.
PFAS blood testing should be more accessible and affordable for patients at risk, she added. "Clinicians should be aware of the potential benefits and limitations of blood PFAS testing, and of possible ways for reducing and preventing further exposure, to enable informed decisions with their patients, taking their medical history and other health risk factors into consideration.
"We can also advocate for stronger regulations that ban globally the use and presence of PFAS in consumer products and in our drinking water," Valvi said. "Most current legislations refer to a limited number of PFAS. However, we are exposed to thousands of PFAS. We need to go further than that."
"Having the pull from consumers to push the government to deal with these problems is essential," said Foster. "If nobody cares about the problem, nobody cares about the solutions. So, we need people to care about the problem."
Foster, Moreira, and Valvi declared no competing interests.
Marilynn Larkin, MA, is an award-winning medical writer and editor whose work has appeared in numerous publications, including Medscape Medical News and its sister publication MDedge, The Lancet (where she was a contributing editor), and Reuters Health.
Marilynn Larkin