With reference to perfluoroalkyl and polyfluoroalkyl substances (PFAS) that are used in making many consumer products, consider the following statements : 1. PFAS are found to be widespread in drinking water, food and food packaging materials. 2. PFAS are not easily degraded in the environment. 3. Persistent exposure to PFAS can lead to bioaccumulation in animal bodies. Which of the statements given above are correct ?
- (a) 1 and 2 only
- (b) 2 and 3 only
- (c) 1 and 3 only
- (d) 1, 2 and 3 ✓ UPSC's answer
Why the answer is (d)
• PFAS are a family of thousands of synthetic chemicals used since the 1940s for their water-, grease- and stain-repellent properties — in non-stick cookware, waterproof fabrics, firefighting foam and food packaging.
• Statement 1 is correct: they leach from products and contaminate drinking water, food and packaging; surveys find them in the blood of most people tested.
• Statement 2 is correct: the carbon–fluorine bond is among the strongest in chemistry, so PFAS resist natural breakdown — hence the name 'forever chemicals'.
• Statement 3 is correct: because they persist and bind to proteins, they accumulate in animal and human tissues, and are linked to cancers, thyroid disease and immune effects.
• Hence 1, 2 and 3, option (d).
Why the other options are wrong
- (a) 1 and 2 only
- Statement 3 on bioaccumulation is also correct.
- (b) 2 and 3 only
- Statement 1 on widespread contamination is also correct.
- (c) 1 and 3 only
- Statement 2 on persistence is also correct.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2024, held on 16 June 2024. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.