UPSC CSE Prelims
Question 36
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 ?
View correct answer and explanation
Correct answer: D
Correct Option: D (2 and 3)
Explanation: Nanoparticles exist naturally as well as artificially; certain metal-oxide nanomaterials are used in cosmetics, and some nanoscale releases raise toxicological risks.
Statement / Pair / Item-wise Analysis:
1. False / does not qualify - Volcanic ash, sea spray and natural combustion can produce nanoparticles without humans.
2. True / qualifies - Titanium-dioxide and zinc-oxide nanoscale particles occur in some sunscreens/cosmetic products.
3. True / qualifies - Some engineered nanoparticles released to air, water or food chains can pose health/environmental risks.
Option-wise Analysis:
A. Incorrect-includes 1 even though Volcanic ash, sea spray and natural combustion can produce nanoparticles without humans.; omits 2 even though Titanium-dioxide and zinc-oxide nanoscale particles occur in some sunscreens/cosmetic products.; omits 3 even though Some engineered nanoparticles released to air, water or food chains can pose health/environmental risks.
B. Incorrect-omits 2 even though Titanium-dioxide and zinc-oxide nanoscale particles occur in some sunscreens/cosmetic products.
C. Incorrect-includes 1 even though Volcanic ash, sea spray and natural combustion can produce nanoparticles without humans.; omits 3 even though Some engineered nanoparticles released to air, water or food chains can pose health/environmental risks.
D. Correct-selects exactly the correct statements/items identified above.