Delhi's air pollution, at its worst ever, is a worrying indicator of serious environment degradation. So severe is the pollution, attributed in the beginning to the burning of crackers during Diwali, that schools have been kept shut for three days and all construction activity banned for five days.

Residents have been advised to stay indoors and work from home. The Delhi government is now scrambling to put emergency remedial measures in place, such as sprinkling water on roads and stopping burning at landfill sites.