State any three causes of air pollution in Calcutta in the 19th century

State any three causes of air pollution in Calcutta in the 19th century.

CALCUTTA had a long history of air pollution :

  1. High levels of pollution were a consequence of the huge population that depended on dung and wood as fuel in their daily life.
  2. The main polluters were the industries and establishments that used steam engines run on coal. The railway line introduced in 1855 brought a new pollutant into the picture - Coal from Raniganj. The high content of ash in Indian coal was a problem.
  3. In 1920, the Rice Mills of Tolly gunge began to burn rice husk instead of coal leading to air filled with black soot falling like drizzling rain.