(i) In the process of development of cities, natural features were flattened out and transformed in response to the growing demand for space for factories, housing and other institutions.
(ii) Large, quantities of waste material and refuge polluted the air, water.
(iii) Excessive noise became a feature of urban life.
(iv) Widespread use of coal in homes and industries in 19th century England raised serious problems in industries cities like Leeds, Bradford and Manchester.
(v) In India calcutta (Kolkata) too had a long history of pollution.
(vi) High levels of pollution were a consequence of the use of dung and wood as a fuel.
(vii) The main polluters were the industries and establishments that used coal.