UPSC Prelims 2014 · Question 38 of 100

UPSC Prelims 2014 question on Nanoparticles Concerns

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.

  1. 1 and 2 only
  2. 3 only
  3. 1 and 3 only
  4. 1, 2 and 3
Show answer

Answer: D. 1, 2 and 3

Verdict

The answer is 1, 2 and 3. Industrial nanoparticles raise concern because they persist, they enter food chains, and they generate free radicals.

Analysis

Statement 1 is CORRECT. Many engineered nanoparticles are chemically very stable and resist degradation, so they accumulate in soil and water. Statement 2 is CORRECT. Their extremely small size lets them cross biological membranes and be taken up by organisms, and their stability means they persist once inside, so they move up food chains. Statement 3 is CORRECT. High surface area and reactive surfaces let nanoparticles generate reactive oxygen species, producing oxidative stress in cells.

Source

Journal of the Royal Society Interface paper on nanoparticle risk.

How to crack it

This is applied reasoning from two properties you already have: nanoparticles are very small and often very stable. Small explains uptake and food chain entry, stable explains persistence and accumulation, and high surface reactivity explains free radicals. Derive each statement from a property rather than trying to recall a toxicology finding. When all listed concerns follow from the same physical property, all of them being correct is the likely answer and pattern instinct against all of the above should be resisted.

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