Question 31 from UPSC CSE 2014 - Environme nt

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?
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.

Accepted Answer

Correct Option: D. 1, 2, and 3

Strategy: Evaluate each statement's plausibility based on nanoparticle properties. Link their small size to environmental accumulation and food chain entry, and connect toxicity studies to free radical generation. Confirm all statements are scientifically sound to select option D.

Key Info: Nanoparticles are materials with at least one dimension sized between 1 and 100 nanometers. Their unique physical and chemical properties, including high surface area and reactivity, make them valuable in various industries like electronics, medicine, cosmetics, and coatings. However, these same properties also contribute to environmental and health risks.

**Environmental Risks**

- **Environmental accumulation:** Due to high stability and persistence, nanoparticles can accumulate in soil, water bodies, and sediments. Industrial waste and product degradation release nanoparticles, leading to contamination of ecological niches.
- **Food chain entry:** Their nanoscale size allows easy penetration into living organisms. Plants can absorb nanoparticles from soil and water; these can then travel through trophic levels, entering food chains and accumulating in higher-order organisms through bioaccumulation and biomagnification.
- **Free radical generation:** Nanoparticles can catalyze redox reactions, resulting in the production of reactive oxygen species (ROS) or free radicals. These species can induce oxidative stress in cells, disrupting cellular components, damaging DNA, proteins, and lipids, and leading to toxicity, inflammation, or disease development.

**Regulatory and Health Concerns**

Studies highlight an incomplete understanding of nanotoxicology. Agencies such as the WHO, EPA, and OECD are developing guidelines for safe use and disposal. For example, titanium dioxide and silver nanoparticles in paints, sunscreens, or antimicrobial coatings have been shown to trigger ROS production and enter aquatic and terrestrial food webs.

**Conclusion**

The safe handling, risk assessment, and regulation of nanoparticles remain a major area of research due to their growing industrial application and potential for far-reaching ecological and human health impacts.

Answer

Option A: 1 and 2 only

Answer

Option B: 3 only

Answer

Option C: 1 and 3 only