What we know about this emerging threat to our water and health
By Paul Mathewson, Staff Scientist
Per- and polyfluoroalkyl substances (PFAS) are an emerging class of chemicals with alarming health impacts. They have been in the news quite a bit recently, so this issue’s column will provide a basic overview of what they are and why we are concerned about them.
PFAS are a class of over 3,000 synthetic chemicals that have been produced since the 1940s. The unique physical and chemical characteristics of PFAS make them resistant to oil, water and temperature. These properties make PFAS very useful chemicals for a wide variety of products.
One of the best-known uses of these chemicals is in firefighting foam. Military bases, airports, and firefighting training areas where these foams are used are among the first places where PFAS contamination has been identified in groundwater here in Wisconsin.
Perhaps the most troubling instance of PFAS pollution is in Marinette, where PFAS from firefighting foam used at the Tyco Fire Products training center has seeped into groundwater, contaminating private wells with PFAS at levels over 27 times higher than what the EPA advises as safe for human health.
PFAS are also commonly used in textile manufacturing (think waterproof outerwear or stain-resistant carpet or upholstery), paper products (e.g., fast food wrappers, pizza boxes), household products (Teflon non-stick cookware), metal plating processes, medical products, personal care products (shampoos, dental floss), and many other products.
Another defining characteristic of PFAS chemicals is a carbon-fluorine chain. The carbon-fluorine bond is very strong, so PFAS do not break down easily, leading some to refer to PFAS as “forever chemicals.” This strong bond means that once PFAS get into the environment, or our bodies, they stick around and accumulate.
There are four primary pathways to the environment that have been identified:
- Fire training and response sites, as mentioned earlier, have been identified due to the use of firefighting foam.
- Facilities that manufacture PFAS-containing products can release PFAS through wastewater discharges, waste disposal, and air emissions.
- Landfills, where the myriad PFAS-containing consumer products and other waste streams ultimately end up, contribute PFAS to the environment through their leachate. Older, unlined landfills, in particular, may be important sources of PFAS to the environment.
- Wastewater treatment plants, where traditional treatment techniques do not remove PFAS, are important pathways via discharge of treated wastewater and land application of biosolids.
Researchers are still working to better understand the health effects of PFAS. So far studies have shown that there can be multiple effects from PFAS exposure: impaired development in infants and children; reduced female fertility; hormone interference; increased cholesterol levels; impaired immune function; increased cancer risk.
Based on the current state of knowledge, the primary way people are exposed to PFAS is through contaminated drinking water and eating food containing PFAS (some PFAS bioaccumulate in fish) or contaminated by its packaging. Inhalation and incidental ingestion of household dust is also a potential pathway, particularly for younger children.
There are currently no Federal or Wisconsin drinking water or groundwater standard for PFAS. The EPA has committed to starting the process of developing a standard for some PFAS compounds by the end of the year. However, this process will likely take up to a decade before a standard is established.
Clean Wisconsin is working at the state level encourage the passage of health standards here in Wisconsin sooner than that. These toxic chemicals are not going anywhere and it is important that we work to ensure that all Wisconsinites can safely drink their water.