Explained: What are ‘forever chemicals’ that are contaminating rainwater globally?

Source: The post is based on the article “Explained: What are ‘forever chemicals’ that are contaminating rainwater globally?” published in Indian Express on 22nd August 2022.

What is the News?

A study has found that rainwater from many places across the globe is contaminated with “per- and polyfluoroalkyl substances”(PFAs) which are called “forever chemicals” because of their tendency to stick around in the atmosphere, rainwater and soil for long periods of time.

What are per-and polyfluoroalkyl substances(PFAs)?

PFAs are man-made chemicals used to make nonstick cookware, water-repellent clothing, stain-resistant fabrics, cosmetics, firefighting forms and many other products that resist grease, water and oil.

PFAs can migrate to the soil, water and air during their production and use. Since most PFAs do not break down, they remain in the environment for long periods of time. Some of these PFAs can build up in people and animals (bioaccumulation) if they are repeatedly exposed to the chemicals.

In April 2024, the Environmental Protection Agency released its first regulations concerning PFAS levels in drinking water.

What harm do PFAs cause?

The United States Environmental Protection Agency(EPA) lists a variety of health risks that are attributed to PFA exposure including decreased fertility, developmental effects in children, interference with body hormones, increased cholesterol levels and increased risk of some cancers. 

Recent research has also revealed that long-term low-level exposure to certain PFAs can make it difficult for humans to build antibodies after being vaccinated against various diseases.

How can PFAs be removed?

There is no known method that can extract and remove PFAs from the atmosphere itself. However, there are many effective methods to remove them from rainwater.

One way to do this would be to use a filtration system with activated carbon. The activated carbon will need to be removed and replaced regularly. Also, the old contaminated material must be destroyed.

Another method is to first place a PFA compound in a solvent called DMSO (dimethyl sulfoxide). Then mixed it with sodium hydroxide (lye) in water. When this mixture was heated up to boiling temperature, the PFA compound began to degrade. However, this method doesn’t work for all PFAs and only works for certain PFA subsets.