From UPSC perspective, the following things are important :
Prelims level : Benzene pollution
Mains level : Not Much
A joint committee appointed by the National Green Tribunal (NGT) to study air pollution in Kerala has pointed out that petrol refuelling stations were a major source of benzene emissions and volatile organic compounds (VOCs).
Why such a move?
- Benzene is a major constituent of evaporative emission due to its high volatility.
Try this PYQ:
Q.Consider the following:
- Carbon monoxide
- Sulphur dioxide
Which of the above are released into atmosphere due to the burning of crop/biomass residue?
(a) 1 and 2 only
(b) 2, 3 and 4 only
(c) 1 and 4 only
(d) 1, 2, 3 and 4
What is Benzene?
- Benzene is a chemical that is a colourless or light yellow liquid at room temperature. It has a sweet odour and is highly flammable.
- It evaporates into the air very quickly. Its vapour is heavier than air and may sink into low-lying areas.
- It dissolves only slightly in water and will float on top of the water.
Its formation and uses
Benzene is formed from both natural processes and human activities.
- Natural sources of benzene include volcanoes and forest fires. Benzene is also a natural part of crude oil, gasoline, and cigarette smoke.
- Some industries use benzene to make other chemicals that are used to make plastics, resins, and nylon and synthetic fibres.
- It is also used to make some types of lubricants, rubbers, dyes, detergents, drugs, and pesticides.
- The major sources of benzene exposure are tobacco smoke, automobile service stations, exhaust from motor vehicles, and industrial emissions.
- Benzene is present in both exhaust and evaporative emissions. Motor vehicles account for approximately 85% of the total benzene emissions.
- However, ingestion and dermal absorption of benzene can also occur through contact with contaminated water.