Pollution

Total Questions: 50

41. Which of the following are the reasons/factors for exposure to benzene pollution? [I.A.S. (Pre.) 2020]

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:

(a) 1, 2 and 3 only
(b) 2 and 4 only
(c) 1, 3 and 4 only
(d) 1, 2, 3, 4 and 5

Correct Answer: (d) 1, 2, 3, 4 and 5

Solution:Benzene is a chemical that is a colourless or light yellow liquid at room temperature. Benzene is formed from both natural processes and human activities and it evaporates into air very quickly. Automobile exhaust, tobacco smoke, wood burning and using varnished wooden furniture and products made of polyurethane, etc. are the factors/reasons for exposure to benzene pollution.

42. Which one of the following is not an instrumental device to check air pollution? [U.P.P.C.S. (Mains) 2013]

(a) Bag Filter
(b) Cyclone Collector
(c) Cyclone Separator
(d) Cyclone Divider

Correct Answer: (d) Cyclone Divider

Solution:Cyclone Divider is not an instrumental device to check air pollution; it's a term describing the physical separation process within a cyclone collector, not a specific device used to monitor air pollution.
Bag Filter: A device that uses fabric filters to trap particulate matter from air.
Cyclone Collector: A device that uses centrifugal force to separate particles from a gas stream by creating a swirling vortex.
Cyclone Separator: Another term for a cyclone collector, emphasizing its function of separating particles.

43. In the cities of our country, which among the following atmospheric gases are normally considered in calculating the value of Air Quality Index? [I.A.S. (Pre) 2016]

1. Carbon dioxide

2. Carbon monoxide

3. Nitrogen dioxide

4. Sulfur dioxide

5. Methane

Select the correct answer using codes given below:

(a) 1, 2 and 3 only
(b) 2, 3 and 4 only
(c) 1, 4 and 5 only
(d) 1, 2, 3, 4 and 5

Correct Answer: (b) 2, 3 and 4 only

Solution:Like other countries, India's Air Quality Index is based on 8 major pollutants-

(a) < 10 micro meter size particulate matter (PM)

(b) <2.5 micro meter size particulate matter (PM 2.5)

(d) Carbon Mono oxide (CO)

(e) Ozone (O3)

(f) Sulphur dioxide (SO2)

(g) Ammonia (NH3)

(h) Lead (Pb)

CO and O3 are measured on the average of 8 hours and other pollutants are measured on the average of 24 hours, Measurement unit for NO2 and O3 is microgram per cubic metre and for CO milligram per cubic meter. Notably, the National Air Quality Index was launched on 17 October, 2014 by Environment Forest and climate change Ministry. This index uses one -Number, One-colour, One- description method.

44. In the context of WHO Air Quality Guidelines, consider the following statements: [I.A.S. (Pre) 2022]

1. The 24-hour mean of PM2.5 should not exceed 15µg/ 2.5 m³ and annual mean of PM2.5 should not exceed 5µg/m³.

2. In a year, the highest levels of ozone pollution occur during the periods of inclement weather.

3. PM10 can penetrate the lung barrier and enter the bloodstream.

4. Excessive ozone in the air can trigger asthma.

Which of the statements given above are correct?

(a) 1, 3 and 4
(b) 1 and 4 only
(c) 2, 3 and 4
(d) 1 and 2 only

Correct Answer: (b) 1 and 4 only

Solution:The updated WHO guidelines state that annual average concentrations of PM2.5 should not exceed 5 µg/m3, while 24-hour average exposures should not exceed 15 µg/m3. PM2.5, fine particulate matter of 2.5 micrometres or less in diameter, is the most dangerous pollutant because it can penetrate the lung barrier and enter the blood system, causing cardiovascular and respiratory disease and cancers. Ozone gas, is one of the most common air pollutants. Ozone contributes to what we typically experience as "smog" or haze. Ozone triggers asthma because it is very irritating to the lungs and airways. It is well known that ozone concentration is directly related to asthma attacks.

45. National Clean Air Programme has been launched by the Central Government in the year: [U.P.P.C.S (Pre) 2020]

(a) 2018
(b) 2017
(c) 2020
(d) 2019

Correct Answer: (d) 2019

Solution:National Clean Air Programme was launched by the Ministry of Environment, Forest and Climate Change in January 2019. Its aim is to tackle the air pollution problem across the country in a comprehensive manner with targets to achieve 20-30% reduction in Particulate Matter (PM 10 & PM 2.5) concentrations by 2024 keeping 2017 as the base year.

46. In which year The air (Prevention And Control of Pollution) Act was enacted? [Uttarakhand P.C.S. (Pre) 2021]

(a) 1980
(b) 1974
(c) 1981
(d) 1986

Solution:The Air (Prevention and Control of Pollution) Act was enacted in 1981 and amended in 1987 to provide for the prevention, control and abatement of air pollution in India. The following are the definitions under the Air (Prevention and Control of Pollution) Act.

• Section 2(a) defines an 'air pollutants' as any solid liquid or gaseous substance which may cause harm or damage the environment, humans, plants, animals or even damage property. A 1987 amendment to the act also added 'noise' in the list of harmful substances.

• The Air Act defines 'air pollution' as the presence of any dangerous pollutant that makes the air unbreathable.

Section 2 (g) of the Act also set up the Central Pollution Control Board (CPCB) whose powers extended to the whole of India. To carry out the directives of the CPCB the act also called for the setting up of the State Pollution Control Board (SPCB) for the individual states of India. toyale (

47. The main air pollutant(s) in metropolitan cities is/are: [M.P.P.S.C. (Pre), 2018]

(a) O₃
(b) CO and SO₂
(c) CO₂ and NO₂
(d) None of the above

Correct Answer: (b) CO and SO₂

Solution:Typical sources of some Air Pollutants in a Ambient Air:

Sl. No.	Air Pollutants	Major Sources
1	Sulphur Dioxide (SO₂)	Fuel combustion, power station, industrial processes, chemical processes, diesel vehicles, solid waste disposal, smelters.
2	Nitrogen Oxide (NOₓ)	Transport (road, rail, passenger and commercial), fuel combustion, power station, industrial boilers, chemical processes, waste incinerators, smelters.
3	Particulate Matter (SPM, RSPM-PM10, RSPM-PM2.5)	Fuel combustion, power station, construction activities, industrial processes, diesel vehicle exhaust, suspended road dust, domestic refuse burning, domestic wood.

Sl. No.

Air Pollutants

Major Sources

Sulphur Dioxide (SO₂)

Fuel combustion, power station, industrial processes, chemical processes, diesel vehicles, solid waste disposal, smelters.

Nitrogen Oxide (NOₓ)

Transport (road, rail, passenger and commercial), fuel combustion, power station, industrial boilers, chemical processes, waste incinerators, smelters.

Particulate Matter (SPM, RSPM-PM10, RSPM-PM2.5)

Fuel combustion, power station, construction activities, industrial processes, diesel vehicle exhaust, suspended road dust, domestic refuse burning, domestic wood.

Sl. No.	Air Pollutants	Major Sources
4	Carbon Monoxide (CO)	Transport, combustion, industrial processes, solid waste disposal, refuse burning
5	Ozone (O₃)	Secondary pollutants formed during photochemical reactions
6	Organic Compounds	Transport, oil-based fuel combustion sources, chemical processes, solvent use, waste incinerator, vaporization of fuel
	Benzene	Petrol combustion products, petrol filling stations, chemical processes
	Poly-nuclear Aromatic Hydrocarbons (PAH)	Fuel combustion, industrial emission
	Volatile Organic Compounds (VOC)	Transport, solvents (especially used in industrial and domestic sectors)
7	Trace Metals	Fuel combustion, chemical processes, transport, metal production and finishing operations, product manufacture
	Lead (Pb)	Lead additives in gasoline, soil-originated particles
	Cadmium (Cd)	Fuel combustion, metal production processes, transport

48. Consider the following statements: [I.A.S. (Pre) 2017]

1. Climate and Clean Air Coalition (CCAC) to Reduce Short-Lived Climate Pollutants is a unique initiative of the G20 group of countries.

2. The CCAC focuses on methane black carbon and hydro-fluorocarbons.

Which of the statements given above is/are correct?

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Correct Answer: (b) 2 only

Solution:The climate and Clean Air Coalition (CCAC) is a voluntary partnership of over 160 governments intergovernmental organizaions and non-governmental organisations found in February, 2012. Notably in 2012 the government of Bangladesh, Canada, Ghana, Mexico, Sweden and the United States alongwith UNEP, initiated efforts to treat short-linked in climate pollutants as an urgent and collective challenge. Along with spreading awareness about the effects of short-lived climate pollutants, the coalition also works for its mitigation strategy and to promote new operations at the regional and national level. Along with this, the allies of the coalition also recognize the fact that minimization of short-lived climate pollutants is capable of working as supplementary and supplement in global efforts to minimize carbon dioxide.

49. Carbon monoxide, emitted by vehicles which turn to carbon dioxide by the catalyst converter, whose ceramic disc is controlled by? [R.A.S./R.T.S.(Pre) 1994]

(a) Silver
(b) Gold
(c) Copper
(d) Palladium

Correct Answer: (d) Palladium

Solution:A catalytic converter is an emission control device that converts toxic gases and pollutants in the exhaust gas to less toxic pollutants by catalyzing a redox reaction. The catalyst itself is most often a mix of precious metals. Palladium and Platinum are two such precious metals used.

50. Smog is essentially caused by the atmospheric presence of: [U.P.P.C.S. (Pre) 2019]

(a) Oxygen and ozone
(b) Ozone and nitrogen
(c) Oxygen and nitrogen
(d) Oxide of nitrogen and sulphur

Correct Answer: (d) Oxide of nitrogen and sulphur

Solution:Smog is a type of intense air pollution. The word 'smog' is a contraction of the words smoke and fog to refer the smoky fog. It is a kind of visible air pollution and is composed of nitrogen oxides, sulphur oxides, ozone, smoke and other particulates. Man-made smog is derived from coal combustion emissions, vehicular emissions, industrial emissions, forest and agricultural fires and photochemical reactions of these emissions.

« Previous 1 2 3 45