Consider the following statements : 1. Other than those made by humans, nanoparticles do not exist in nature. 2. Nanoparticles of some metallic oxides are used in the manufacture of some cosmetics. 3. Nanoparticles of some commercial products which enter the environment are unsafe for humans. Which of the statements given above is/are correct ?
- (a) 1 only
- (b) 3 only
- (c) 1 and 2
- (d) 2 and 3 ✓ UPSC's answer
Why the answer is (d)
• Statement 1 is wrong: nanoparticles occur naturally — in volcanic ash, sea spray, forest-fire smoke, dust and even biological structures.
• Statement 2 is correct: nanoparticles of titanium dioxide and zinc oxide are used in sunscreens and cosmetics for transparent UV protection.
• Statement 3 is correct: engineered nanoparticles released into water and soil can be taken up by organisms and enter food chains, and some (e.g. nano-silver, certain metal oxides) are toxic to humans and wildlife.
• Regulators are still developing standards for nanomaterial safety.
• Hence 2 and 3, option (d).
Why the other options are wrong
- (a) 1 only
- Statement 1 is wrong: nanoparticles exist in nature.
- (b) 3 only
- Statement 2 on cosmetics is also correct.
- (c) 1 and 2
- Statement 1 is wrong; statement 3 is correct.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2022, held on 5 June 2022. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.