By Mike Ekberg, manager of water resource monitoring and analysis
You’ve probably heard about PFAS, but what are they and why are they such a hot topic today?
PFAS or per- and polyflouroalkyl substances are a group of chemicals developed in the 1940s that can repel water, dirt, and grease; tolerate high temperatures; make fabrics stain resistant; and can be used to extinguish fires. They are nearly indestructible and last for a really long time. According to the U.S. Food and Drug Administration, there are nearly 5,000 PFAS compounds in existence today.
Widely used in consumer products
PFAS are widely used in consumer products such as cookware, pizza boxes and stain repellants. The properties of PFAS make them well suited for the creation of nonstick cookware surfaces, water resistant fabrics, stain resistant carpets, and for use in some firefighting foams. These products are popular with consumers but the PFAS chemicals used in their production are bad for the environment.
PFAS are bad news for the environment
Unfortunately, some of the same properties that make PFAS valuable in manufacturing, make them bad news for clean air, soil and water. The chemical bonds that hold PFAS molecules together make them highly resistant to breaking down in the natural environment. Once they get into soil and water, they persist for very long periods of time. Because PFAS are so persistent, they can buildup (bioaccumulate) in fish and wildlife. They can also accumulate in the blood and serum of people. Studies have shown that low levels of PFAS are commonly present in municipal wastewater sludge and effluent as well in many rivers and streams where treated or untreated human sewage is discharged. The issue of PFAS in the environment is not going to go away anytime soon.
Widespread exposure to PFAS in the U.S. population
Humans can be exposed to PFAS by consuming PFAS-contaminated food and water or by using products that contain PFAS.
Studies have shown widespread exposure of PFAS in humans. (link to study Fourth National Report on Human Exposure to Environmental Chemicals, Updated Tables). Yet, no one knows for sure the effects on human health, according to the Centers for Disease Control and Prevention.
Human health effects uncertain
Studies of laboratory animals given large doses of PFAS have found that some PFAS may affect growth and development, reproduction, thyroid function, the immune system, and injure the liver. Epidemiologic studies have examined a number of health effects and associated exposure to some PFAS compounds with the following:
- High cholesterol
- Increased liver enzymes
- Decreased vaccination response
- Thyroid disorders
- Adverse reproductive and developmental effects
Nonetheless, more research is needed to better assess human health effects from exposure to PFAS. For more information on human health related effects of PFAS and what people can do to minimize exposure to these compounds visit Ohio EPA’s PFAS webpage.
PFAS what’s next?
Science is working to better understand how PFAS interacts with the human body and what levels of exposure are safe. Meanwhile industry is phasing out certain PFAS chemicals and replacing them with others. Whether these new PFAS compounds are safer is unknown.
A lack of coherent policies and standards for PFAS in drinking water at the federal level has, in many cases, led to state regulatory agencies adopting their own standards. This has led to a hodgepodge of different drinking water standards for various PFAS chemicals across the country.
Public water systems with PFAS in their source water find themselves in the unenviable position of having to make decisions without federal guidance as to which standards they should apply and what treatment options are most cost effective and ensure consumer safety. The way forward on this issue remains a work in progress.
Most manufactured chemicals we use end up in the environment
Perhaps the most striking point in dealing with the issue of PFAS in the environment is these compounds are a reminder to us all that most manufactured chemicals we use as consumers end up in the natural environment in one way or another.
Our consumer-driven society creates strong incentives to create new chemical compounds in manufacturing and industry each year. Yet, our knowledge of the ultimate fate of these compounds and their potential impacts on human health and the environment is often sorely lacking.
In Part II, I’ll take a closer look at the issue of PFAS in source waters for public drinking water systems and how this issue is being addressed at the national, state, and local levels.