- Sulphur dioxide is responsible for turning Taj Mahal yellow.
- It also gets dull due to mineral impurities present in the marble get oxidised and create brown stains.
- The Air Pollution Monitoring Laboratory at Agra has found that the level of air pollutants such as Sulphur-di-oxide and Nitrous Oxide gases - are generally responsible for turning Taj Mahal yellow.
- It happens due to a large number of power plants and industries structured around Taj Mahal.