Question

The best indicator(s) for monitoring of air pollution is/are

• A. Sulphur dioxide
• B. Sulphur dioxide and suspended particles
• C. Oxides of nitrogen and polyaromatic hydrocarbons
• D. Carbon monoxide

Hint:

Community air quality monitoring classically combines a gaseous pollutant with particulate matter.

Answer 1

The Correct Option is B

This question asks which pollutant or pair of pollutants is used as the standard way to track how polluted the air in a community is.

1. Sulphur dioxide: This gas comes mainly from burning coal and diesel, but tracking it alone misses dust and smoke particles floating in the air, so it does not give the full picture on its own.
2. Sulphur dioxide and suspended particles: Pairing a gas marker with a particle marker covers both combustion gases and solid or liquid particles in the air. This combined pair became the classical, widely used index for judging community air quality.
3. Oxides of nitrogen and polyaromatic hydrocarbons: These matter a lot for vehicle exhaust and combustion byproducts specifically, but they are not the routine pair used for general community air monitoring.
4. Carbon monoxide: This gas is important near traffic or in closed spaces, but on its own it is not the general indicator used to judge overall community air quality.

Combining a gaseous pollutant with a particulate one gives a fuller and more balanced read on air quality than any single pollutant alone.

So the best indicator for monitoring air pollution is sulphur dioxide together with suspended particles.