Why does Mathura refinery pose problems to the Taj Mahal?
Answer:
Mathura oil refinery and other industries of the neighboring towns which burn fossil fuels are responsible for the discoloration of Taj Mahal. These industries release soot particles and gases like Sulphur dioxide and nitrogen oxides into the atmosphere. The soot particles turn the color of the marble to yellow and the gases react with water to form acid rain which corrodes the marble of the monument. This phenomenon is also called “marble cancer”.