The US Environmental Protection Agency is preparing to issue a draft regulation limitation of two fluorinated chemicals, known by their abbreviations PFOA And PFOS, in drinking water. These chemicals are two types of PFAS, a broad class of substances often referred to as “forever chemicals” because they are very persistent in the environment.
PFAS are widely used in hundreds of products, from non-stick cookware to food packaging, stain- and water-resistant clothing, and fire-fighting foam. Studies show that high levels of exposure to PFAS can lead to health effects that includes reduced immune system functionincreased cholesterol levels and increased risk of kidney or testicular cancer.
Population surveys over the past 20 years show that most Americans have been and have been exposed to PFAS detectable levels in their blood. The new regulation aims to protect public health by setting an enforceable maximum standard that limits how much of the two target chemicals can be present in drinking water – one of the main human exposure routes.
These three articles from the archives of The Conversation explain the growing concern about the health effects of PFAS exposure and why many experts support national regulation of these chemicals.
1. Ubiquitous and persistent
PFAS are useful in many types of products because they resist water, grease and stains and protect against fire. Studies have shown that most products labeled stain or water resistant contain PFAS, even if those products are labeled “non-toxic” or “green.”
“Once people are exposed to PFAS, the chemicals remain in their bodies for a long time — months to years, depending on the specific compound — and can build up over time,” Middlebury College environmental health scientist wrote. Kathryn Crawford. A 2021 review of PFAS toxicity studies in humans “concluded with a high degree of confidence that PFAS contributes to thyroid disease, elevated cholesterol, liver damage, and kidney and testicular cancer.”
The review also found strong evidence that exposure to PFAS in the womb increases the likelihood that babies will be born with low birth weights and have a reduced immune response to vaccines. Other possible effects that have yet to be confirmed include “inflammatory bowel disease, decreased fertility, breast cancer, and an increased chance of miscarriage and developing high blood pressure and preeclampsia during pregnancy.”
“Collectively, this is a formidable list of diseases and conditions,” Crawford noted.
Read more: What are PFAS? An environmental scientist explains
2. Why national regulation is needed
Under the Safe Drinking Water Act, the Environmental Protection Agency has the authority to establish enforceable national regulations for drinking water contaminants. It may also require state, local and tribal governments, which manage drinking water supplies, to monitor public water systems for the presence of contaminants.
However, so far the agency has not set binding standards limiting exposure to PFAS, although it has issued non-binding advisory guidelines. In 2009, the agency set a health advisory level for PFOA in drinking water of 400 parts per trillion. In 2016, it lowered this recommendation to 70 parts per trillion, and in 2022 lowered this threshold to almost zero.
But many scientists have found fault with this approach. EPA’s one-by-one approach to assessing potentially harmful chemicals “doesn’t work for PFAS, given the sheer volume and the fact that manufacturers commonly replace toxic chemicals with ‘deplorable substitutes’ — similar, lesser-known chemicals that also affect the health of the threaten humans and the environment,” wrote the North Carolina State University biologist Carol Kwiatkowski.
In 2020, Kwiatkowski and other scientists pushed the EPA for it manage the entire class of PFAS chemicals as a group, instead of one by one. “We also support an ‘essential uses’ approach that would limit their production and use to products that are critical to health and the proper functioning of society, such as medical devices and safety equipment. And we have recommended developing safer non-PFAS alternatives,” she wrote.
Read more: PFAS ‘forever chemicals’ are widespread and threaten human health – here’s a strategy to protect the public
AP Photo/Mike Groll
3. Break down PFAS
PFAS chemicals are ubiquitous in water, air, soil and fish around the world. Unlike some other types of pollutants, there is no natural process that breaks down PFAS once they enter water or soil. Many scientists are working on ways to capture these chemicals from the environment and break them down into harmless components.
There are ways to filter PFAS from water, but that’s just the beginning. “Once PFAS is captured, you have to remove the PFAS loaded activated carbon, and PFAS is still moving around. If you bury contaminated materials in a landfill or elsewhere, PFAS will eventually leach. That’s why it’s essential to find ways to destroy it,” Michigan State University chemists wrote ADaniel Jones And Hui Li.
Combustion is the most common technique, they explained, but that typically requires heating the materials to about 1,500 degrees Celsius (2,730 degrees Fahrenheit), which is expensive and requires special incinerators. Several chemical processes offer alternatives, but the approaches developed so far are difficult to scale up. And converting PFAS into toxic by-products is a major concern.
“If there’s one lesson we can learn, it’s that we need to think through the entire product lifecycle. How long do we really need chemicals to last?” Jones and Li wrote.
Read more: How to destroy a ‘forever chemical’ – scientists discover ways to eliminate PFAS, but this growing global health problem won’t go away anytime soon
Editor’s Note: This story is a collection of articles from the archives of The Conversation.
