Perfluorinated alkylated substances, or PFAS, are a synthetic group of compounds that have a huge range of uses, from non-stick pans to waterproof and stain proof material, firefighting foam, and even jet engines. They are informally known as "forever chemicals" because they are extremely resilient and don't fully degrade.
This characteristic is a double-edged sword. On one hand, they are extremely versatile for manufacturing, on the other, it is very difficult to get rid of them once they enter the environment – and humans. Given how common they are and how often they are not disposed of safely, PFAS have shown up in high levels in humans and animals over the 70 years since their creation.
As always there’s a complexity to this issue, so it is important to analyze what is known, what’s being researched, and what is yet-to-be known about this broad class of chemicals.
PFAS And Human Health
There are around 4,700 different chemicals in the PFAS family so there has never been a case-by-case study of every single one of them. Two notorious ones, however, are perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), which have been at the center of environmental scandals.
PFOS is considered a possible carcinogenic to humans by the International Agency for Research on Cancer, a branch of the World Health Organization. In human studies, high exposure to this chemical has been linked to thyroid disease, liver damage, increased cholesterol level, and testicular and kidney cancer. There are also increased risks for pregnant women such as higher blood pressure, lower birth weight for the baby, and a reduced response to vaccines.
There are many other conditions, albeit with more tenuous links than those listed above. In general, there is still a lot that we don’t know about these chemicals, like the level of exposure needed to create an increased risk, the exact mechanism by which these chemicals cause severe reactions, and the potential effects on wild and domestic animals.
The exposure level is important given that these chemicals are present in almost all of us. However, several studies have shown that levels of PFOS and PFAS have lowered in the general population over the years, as they are used less and less in industrial processes and are now more regulated.
PFOA is not easily broken down by organic processes, water, light, or bacteria, so in the human body, it has a half-life of about three years. Until they are removed from the environment totally, it is very difficult not to be exposed to them.
Removing These Chemicals From The Environment
Exposure is obviously higher if you work directly with these chemicals, but exposure in everyday life can come from consumer goods, water (including bottled), and food. Water sources are of particular concern given the history of chemical companies dumping these chemicals in them.
There are several methods that have been employed to successfully remove the chemicals from water for public consumption. Over the last few years, there have also been investigations in techniques that can destroy the chemicals completely via electrochemical oxidation and even with a bacterium.
However, stricter regulations on the use and disposal of PFAs is vital as they are still largely unregulated. Governments need a plan to manage the entire class of PFAS to protect public health while safer alternatives are developed.