Per- and polyfluoroalkyl substances

In News: A recent study published in Environment Science and Technology has found that rainwater from many places across the globe is contaminated with “per- and polyfluoroalkyl substances,” (PFAs).

What are PFAs?

• According to the US Centre for Disease Control and Prevention (CDC), 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.
• They are called as “forever chemicals” because of their tendency to stick around in the atmosphere, rainwater and soil for long periods of time.
• 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 if they are repeatedly exposed to the chemicals.

What harm do PFAs cause?

• A variety of health risks that are attributed to PFA exposure, include 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 these chemicals be removed from rainwater?

• While there is no known method that can extract and remove PFAs from the atmosphere itself, there are many effective, albeit expensive, methods to remove them from rainwater that has been collected through various rainwater harvesting methods.
• 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.

Source: Indian Express

Previous Year Question

Q.1) With reference to polyethylene terephthalate, the use of which is so widespread in our daily lives, consider the following statements: (2022)

1. Its fibres can be blended with wool and cotton fibres to reinforce their properties.
2. Containers made of it can be used to store any alcoholic beverage.
3. Bottles made of it can be recycled into other products.
4. Articles made of it can be easily disposed of by incineration without causing greenhouse gas emissions.

Which of the statements given above are correct ?

1. 1 and 3
2. 2 and 4
3. 1 and 4
4. 2 and 3