Question

Which of the following is a weightless pollutant ?

• A. Sewage and exhaust emissions
• B. SO2 and NO2
• C. Photochemical smog
• D. Heat, sound and radioactive wastes

Answer 1

The correct option is D Heat, sound and radioactive wastes

Radiation, that is given off by nuclear waste is extremely damaging to organisms, because it causes mutations at a very high rate.

At high doses, nuclear radiation is lethal but at lower doses, it creates various disorders, the most frequent of all being cancer. Therefore, nuclear waste is an extremely potent pollutant.

Heated (thermal) waste waters flowing out of electricity-generating units, e.g., thermal power plants, constitute another important category of pollutants.

Thermal waste water eliminates or reduces the number of organisms sensitive to high temperature, and may damage the indigenous flora and fauna.

Noise is an unwanted sound, or sound which produces unpleasant effects and discomfort on the ears. Sound becomes unwanted when it either interferes with normal activities such as sleeping, conversation, or disrupts or diminishes one's quality of life.
All the three are pollutants but does not have any physical weight.

So the correct answer is "Option D"