The Taj Mahal and other heritage monuments in and around Agra are facing a major threat from dust-laden air

Unabated construction is making the city's green cover disappear and drying up water bodies, adding to the dust levels

"The collision (of the dust with the marble) results in micro-scratches that retain moisture which attracts pollutants and gaseous substances," said P.C. Gupta, head of the Archaeological Survey of India's (ASI) chemical department.