Q1. [2] deep thorough-understanding
Evaluate the effectiveness of the following two measures in controlling air pollution from factories: (i) replacing coal with oil or gas as fuel, and (ii) installing taller chimneys. Which measure addresses the root cause of pollution, and why?
Generated by claude-sonnet-4-6 · 2026-06-26 13:37 · grounding rag
Model Answer
(i) Replacing coal with oil or gas is more effective as it directly reduces smoke and harmful emissions at the source.
(ii) Taller chimneys only disperse pollutants over a wider area; they do not reduce pollution.
Measure (i) addresses the root cause because it eliminates the burning of coal — the primary source of smoke and pollutant gases like sulphur dioxide and carbon monoxide — rather than merely relocating the problem.
Source: Control of Environmental Degradation, Chapter 6
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Explanation
- The passage explicitly states: "Smoke can be reduced by using oil or gas instead of coal in factories" — use this as your evidence.
- Taller chimneys are not mentioned in the passage as a solution; the textbook focuses on fitting electrostatic precipitators, scrubbers, etc. — so taller chimneys only disperse, not reduce, pollution.
- The examiner wants you to distinguish between treating the symptom (dispersal via chimneys) vs. treating the cause (changing the fuel). Always link back to the source of pollution.