Humayun's Tomb Is Not Being Encroached Upon. It Is Being Dissolved.
The study is among the first to provide multianalytical laboratory evidence - using XRF, XRD, FTIR, SEM-EDX and CHNS analysis - that Delhi's air pollution is chemically altering the sandstone of a major UNESCO World Heritage Site, adding scientific weight to concerns about preventive conservation strategies at Humayun's Tomb and comparable monuments in similarly polluted cities.