Question:
Why is it advised that industries should switch over to cleaner fuels such as CNG and LPG in the Taj Mahal zone in Agra?
Solution:
Pollutants in air are discolouring white marble of Taj Mahal. The Mathura Oil Refinery near Agra as well as various industries in and around Agra are
emitting gaseous pollutants such as sulphur dioxide and nitrogen dioxide into the air which cause acid rain.
Acid rain react with the carbonates present in marble (calcium carbonate) and limestone of a monument and corrode it slowly (dissolve it slowly).