When white is grey
The impact of air pollution is not restricted to living organisms alone. It has been cited as one of the key factors causing the degradation of historical buildings and monuments. Pollutants in the air cause corrosion, discolouration and ultimately destruction of these priceless monuments. Built eons ago, these reminders of our cultural heritage are being eroded by smoke, smog and waste materials, that we create.
Here are five sites in India that have suffered the ignominy of ill-usage. Can you identify them?