There is some concern regarding the nanoparticles of some chemical elements that are used by the industry in the manufacture of various products. Why? 1. They can accumulate in the environment, and contaminate water and soil. 2. They can enter the food chains. 3. They can trigger the production of free radicals. Select the correct answer using the code given below.
- (a) 1 and 2 only
- (b) 3 only
- (c) 1 and 3 only
- (d) 1, 2 and 3 ✓ UPSC's answer
Why the answer is (d)
• Engineered nanoparticles (silver, titanium dioxide, zinc oxide) used in cosmetics, textiles and coatings are so small and reactive that they persist and accumulate in water and soil (1), are taken up by organisms and move through food chains (2), and their high surface reactivity can generate reactive oxygen species (free radicals) causing oxidative damage to cells (3).
• These concerns drive nano-toxicology research and regulation.
• Hence 1, 2 and 3, option (d).
Why the other options are wrong
- (a) 1 and 2 only
- Free-radical generation is also a concern.
- (b) 3 only
- Accumulation and food-chain entry are also concerns.
- (c) 1 and 3 only
- Food-chain entry is also a concern.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2014, held on 24 August 2014. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.