* Dust and dirt: The Taj Mahal is located in a dusty environment, and the dust and dirt that settles on the building can cause it to look dirty and tarnished.

* Pollution: The Taj Mahal is also exposed to pollution from vehicles and factories, which can cause the building to become discoloured.

* Biological growth: The Taj Mahal is also home to a variety of biological organisms, such as bacteria, algae, and fungi, which can grow on the building and cause it to look unsightly.

* Water damage: The Taj Mahal is also susceptible to water damage, which can cause the building to become stained and discoloured.