Consider the following statements:Other than those made by humans, nanoparticles do not exist in nat

Q: What is UPSC Prelims?

UPSC Prelims is a competitive examination conducted in India. This question is from the 2022 UPSC Prelims Science & Technology paper.

Q: How can I prepare for UPSC Prelims Science & Technology?

To prepare for UPSC Prelims Science & Technology, practice previous year questions (PYQs), understand concepts thoroughly, and solve mock tests regularly. This 2022 question covers Nanotechnology, Robotics & Emerging Technologies topic.

Q: What is the difficulty level of this question?

This UPSC Prelims 2022 Science & Technology question has a easy difficulty level.

Q: Where can I find more UPSC Prelims previous year questions?

You can find more UPSC Prelims previous year questions on AspirantMitraa. Browse by subject, topic, year, and difficulty level to practice effectively.

Question

Consider the following statements:Other than those made by humans, nanoparticles do not exist in nature.Nanoparticles of some metallic oxides are used in the manufacture of some cosmetics.Nanoparticles of some commercial products which enter the environment are unsafe for humans.Which of the statements given above is/are correct?

Accepted Answer

Correct Answer: D — 2 and 3Step-by-step Solution:Statement 1 — Nanoparticles exist only when made by humans: This is incorrect. Nanoparticles occur widely in nature — this is a well-established scientific fact. Natural sources of nanoparticles include: (a) Interplanetary dust — a significant fraction of cosmic dust falling on Earth (thousands of tonnes per year) is in the nanoparticle size range; (b) Atmospheric particles — volcanic ash, sea spray, forest fire smoke; (c) Biogenic sources — viral particles, some biological molecules; (d) Geological processes — iron oxides, iron sulfides, silver, and gold nanoparticles occur naturally in the environment. ✗Statement 2 — Metal oxide nanoparticles used in cosmetics: This is correct. Many cosmetic products (especially sunscreens and skin creams) contain metal oxide nanoparticles: (a) Titanium dioxide (TiO₂) nanoparticles — used in sunscreens for UV protection, providing transparency while blocking UV rays; (b) Zinc oxide (ZnO) nanoparticles — similarly used in sunscreens; (c) Silver nanoparticles — used in deodorants and some skin products for antimicrobial properties; (d) Gold nanoparticles — used in some anti-aging skincare products. ✓Statement 3 — Nanoparticles from commercial products entering the environment are unsafe: This is correct. There is growing scientific evidence that certain nanoparticles from commercial products can pose health and environmental risks when they enter the environment: (a) Silver nanoparticles from clothing and antibacterial products wash into waterways, affecting aquatic organisms; (b) Titanium dioxide nanoparticles from sunscreens affect coral reefs; (c) Workers exposed to manufactured nanoparticles during production face occupational health risks; (d) Consumers using products containing nanoparticles may absorb them through skin, inhalation, or ingestion. ✓Why other options are incorrect:Options A, B, and C: Incorrect because statement 1 is wrong — nanoparticles do exist naturally.Key Concept: Nanotechnology: Materials science at the nanoscale (1–100 nm); nanoparticles exhibit different properties than bulk materials (different optical, electrical, magnetic, chemical properties); applications: medicine (drug delivery, cancer treatment), electronics, energy, cosmetics, textiles. Nanotoxicology: Study of potential toxic effects of nanoparticles; concerns about: accumulation in organisms (bioaccumulation), ability to cross biological barriers (blood-brain barrier, lung-blood barrier), reactive oxygen species generation, antimicrobial resistance when silver nanoparticles enter aquatic ecosystems.

Master UPSC Prelims with Our Test Series

More Questions from Nanotechnology, Robotics & Emerging Technologies

Frequently Asked Questions

Master UPSC Prelims with Our Test Series

More Questions from Nanotechnology, Robotics & Emerging Technologies

Frequently Asked Questions