Calcutta (Kolkata) had a long history of air pollution. Explain any five reasons for it.

The reasons for air pollution in Calcutta were:

(i) Dung and wood were the most dependable fuels for the populace at that time.

(ii) Steam engines used by the industries were run on coal.

(iii) In 1855, the introduction of the railways brought coal from Raniganj which had a high content of ash, which polluted the air.

(iv)The fog in the city, combined with smoke to create thick smog.

(v) Due to the prevalence of marshy land, the resulting fog combined with smoke to generate thick smog.

Even though the Bengal Smoke Nuisance commission managed to control the industrial pollution, the levels of domestic pollution still remained high.