UPSC Prelims 2020 GS Paper I · Q48 of 99 Environment & Ecology medium

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. (a) 1, 2 and 3 only
  2. (b) 2 and 4 only
  3. (c) 1, 3 and 4 only
  4. (d) 1, 2, 3, 4 and 5 ✓ UPSC's answer

Why the answer is (d)

• Benzene is a volatile aromatic hydrocarbon and a known carcinogen (leukaemia); exposure comes from combustion and from products containing it.

• Automobile exhaust and petrol vapour (1) and tobacco smoke (2) are the largest sources of public exposure; wood and biomass burning (3) also emits benzene.

• Indoor sources include varnishes, paints and glues on wooden furniture (4) and polyurethane foams, adhesives and plastics (5), which off-gas benzene.

• Hence 1, 2, 3, 4 and 5, option (d).

Why the other options are wrong

(a) 1, 2 and 3 only
Varnished furniture and polyurethane products also release benzene.
(b) 2 and 4 only
Vehicle exhaust, wood burning and polyurethane are also sources.
(c) 1, 3 and 4 only
Tobacco smoke and polyurethane products are also sources.

Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2020, held on 4 October 2020. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.

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