Forever chemicals threaten human health and the environment.
Per- and polyfluoroalkyl substances (PFAS) refer to a broad class of thousands of synthetic chemicals widely used in all aspects of life. They are increasingly classified as environmental pollutants, some of which are associated with negative effects on human health.
This group of chemicals has been around since the 1940s and is used in the production of many consumer and industrial products, such as non-stick cookware, waterproof fabrics, and firefighting foams. PFAS are sometimes called “forever chemicals” because of their ability to persist in nature for thousands of years.
All of these compounds contain carbon-fluorine bonds, some of the strongest chemical bonds in organic chemistry. This means they resist breaking down when used or left in the environment, and most can easily migrate in nature long distances from their source.
What do PFAS compounds do?
Per- and polyfluoroalkyl substances (PFASs) possess a wide range of different physical and chemical properties and can exist in the form of gases, liquids, or solid polymers. They are widely used because of their unique desirable properties. For example, they are stable at high temperatures, and many are also surfactants, enabling different types of liquids to mix. They also prevent the absorption of water, oils, and grease, in addition to providing stability, durability, and reducing friction. Because of these unique properties, PFASs are used in a variety of products and applications, including food packaging, non-stick cookware, coatings, electrical wiring insulation, metal corrosion reduction, firefighting foams, waterproof clothing, textiles, and outerwear, stain-resistant carpets and textiles, and personal protective equipment.
PFASs are also used in industries such as semiconductors, plastics, composite resins, and others, as well as in aerospace, defense, automotive, and aviation industries.
How are people exposed to them?
Human exposure to per- and polyfluoroalkyl substances (PFASs) is widespread but varies depending on geography and the nature of the work.
Pers and polyfluoroalkyl substances are widely used in the manufacture of thousands of products, and over time, these substances can leach into soil, water, and air.
Humans are most likely exposed to these chemicals by consuming contaminated water or food, using products made from them, or breathing air containing their particles. Because they decompose slowly, they can accumulate in the blood over time in humans and animals. According to a US report issued by the Centers for Disease Control and Prevention, based on data from the National Health and Nutrition Examination Survey (NHANES), 97% of Americans have PFASs in their blood.
Per- and polyfluoroalkyl substances (PFASs) pose a public health concern because they are widely detected in blood and urine samples and are used in hundreds of products worldwide, increasing human exposure. These substances persist in nature for long periods, and as a result, humans may face the risk of bioaccumulation of large quantities of these chemicals. Because there are multiple types of PFASs, which are often found in complex mixtures and in various everyday products, researchers face challenges in studying them. More research is needed to fully understand all sources of exposure and whether and how they may cause health problems.
Who is most at risk?
Some adults are exposed to these chemicals at higher rates than others due to their occupation or where they live. For example, industrial workers involved in the manufacture or processing of PFASs or products containing them, or people living near their production facilities, may have greater exposure to these chemicals.
Children are among the most sensitive groups to the harmful effects of chemicals, including per- and polyfluoroalkyl compounds (PFASs), because they are still developing and are likely to be exposed to them more than adults. Children's water, food, and air intake are larger relative to their weight than adults. Additionally, children often pick up household dust from floors, carpets, and toys, which are contaminated with these compounds.
Key Health Risks
Once people are exposed to per- and polyfluoroalkyl compounds (PFASs), these chemicals remain in their bodies for a long time, from months to years, depending on the specific compound, and can accumulate over time.
Research consistently shows that per- and polyfluoroalkyl compounds (PFAS) are associated with a variety of adverse health effects. A review by a team of experts investigating the toxicity of these compounds concluded with a high degree of certainty that they are associated with a variety of health effects, including altered immune and thyroid function, liver disease, dysregulation of lipids and insulin, kidney disease, reproductive outcomes, developmental impairment, and cancer.
Furthermore, the study concluded that per- and polyfluoroalkyl chemicals also affect babies exposed in utero by increasing the likelihood of them being born with a lower birth weight, responding less effectively to vaccines, and impairing mammary gland development, which can negatively impact maternal health and breastfeeding.
The review also found evidence that PFAS may contribute to a number of other disorders, although more research is needed.