UPSC Prelims 2020 · Question 8 of 100

UPSC Prelims 2020 question on Benzene Pollution Sources

Which of the following are the reasons/factors for exposure to benzene pollution?

1. Automobile exhaust

2. Tobacco smoke

3. Wood burning

4. Using varnished wooden furniture

5. Using products made of polyurethane

Select the correct answer using the code given below:

  1. 1, 2 and 3 only
  2. 2 and 4 only
  3. 1, 3 and 4 only
  4. 1, 2, 3, 4 and 5
Show answer

Answer: D. 1, 2, 3, 4 and 5

Verdict

Correct statements: 1, 2, 3, 4 and 5 → Option (d).

Analysis

Active and passive exposure to tobacco smoke is a significant source of benzene exposure. Hence statement 2 is correct.

Natural sources of benzene include volcanoes and forest fires. Benzene is also a natural part of crude oil, gasoline, and cigarette smoke. Hence automobile exhaust (statement 1) and tobacco smoke (statement 2) are correct.

Wood burning (statement 3) is a correct source as wood dyes and finishes contain various chemicals including benzene-related compounds.

Wood finishes such as paints and some wood treatments (statement 4) can contain chemicals including toluene or butanol, and varnished wooden furniture can emit benzene. Hence statement 4 is correct.

During fires, polyurethane foams burn rapidly and produce dense smoke — carbon monoxide is most common but smoke also contains benzene, toluene, nitrogen oxides and hydrogen cyanide. Hence statement 5 is correct.

Automobile exhaust accounts for the largest source of benzene in the general environment.

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