d B is a standard abbreviation used for the quantitative expression of

Step-by-step solution

Noise pollution is a physical form of pollution that affects the receiver directly. dB (decibel) is a standard abbreviation used for the quantitative expression of noise. Noise or pollutant sound has a value of 80 ~dB and above, it harms hearing system. The WHO has fixed 45 ~dB as the safe noise level for a city.