There is some concern regarding the nanoparticles of some chemical elements that are used by the ind

Q: What is UPSC Prelims?

UPSC Prelims is a competitive examination conducted in India. This question is from the 2014 UPSC Prelims Environment & Ecology paper.

Q: How can I prepare for UPSC Prelims Environment & Ecology?

To prepare for UPSC Prelims Environment & Ecology, practice previous year questions (PYQs), understand concepts thoroughly, and solve mock tests regularly. This 2014 question covers Water Pollution – Sources, Eutrophication & Treatment topic.

Q: What is the difficulty level of this question?

This UPSC Prelims 2014 Environment & Ecology question has a hard difficulty level and is marked as an important question.

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Question

There is some concern regarding the nanoparticles of some chemical elements that are used by the industry in the manufacture of various products. Why?They can accumulate in the environment and contaminate water and soil.They can enter the food chains.They can trigger the production of free radicals.Select the correct answer using the code given below.

Accepted Answer

Correct Answer: D — 1, 2 and 3Step-by-step Solution:Nanoparticles are particles with dimensions between 1 and 100 nanometres. Many industrial nanoparticles (silver, titanium dioxide, zinc oxide, carbon nanotubes, quantum dots, etc.) have unique properties at the nanoscale that make them commercially valuable but also potentially hazardous. All three concerns are valid:Item 1 — Can accumulate in environment and contaminate water and soil: This is correct. Many engineered nanoparticles are chemically stable and highly persistent in the environment — they do not degrade easily. Once released (from consumer products, industrial effluents, manufacturing processes), they can: accumulate in water bodies and soil; bind to sediments; persist for long periods. Silver nanoparticles (from antibacterial products), titanium dioxide nanoparticles (from sunscreens), and carbon nanotubes all accumulate in the environment. ✓Item 2 — Can enter the food chains: This is correct. Due to their extremely small size, nanoparticles can be absorbed by: plants (through root uptake from soil and water); microorganisms (bacteria, algae); invertebrates and small organisms in water. Through trophic transfer (bioaccumulation and biomagnification), they can move up the food chain — from soil/water microorganisms → invertebrates → fish → birds/mammals. ✓Item 3 — Can trigger production of free radicals: This is correct. Many nanoparticles can induce oxidative stress in biological cells — specifically by triggering the generation of reactive oxygen species (ROS) or free radicals. Free radicals are highly reactive molecules that can damage DNA, proteins, and cell membranes, leading to: inflammation, cell death, mutagenesis, and potentially cancer. This mechanism of nanotoxicity is well-documented in scientific literature for nanoparticles of zinc oxide, silver, titanium dioxide, and others. ✓Key Concept: Nanotoxicology: Study of the toxic potential of nanomaterials; major concerns: ability to cross biological barriers (blood-brain barrier, lung-blood barrier, placental barrier); the novel properties of nanomaterials (large surface area to volume ratio, quantum effects) can make them behave differently from bulk materials of the same composition. Regulatory challenges: Standard toxicology tests may not adequately characterise nano-specific risks. India's Nano Science and Technology Initiative (NSTI) promotes nanotechnology development while awareness of safety concerns is growing.

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