Masks are back, construction banned and schools shut as toxic air engulfs New Delhi

Masks are back on the New Delhi streets as residents grapple with the annual surge in air pollution that has engulfed the Indian capital region. Primary schools have been ordered shut this week and polluting vehicles and construction banned as a thick cover of smog hangs over the city. Authorities have warned the pollution will worsen with Diwali, the Hindu festival of light that features the lighting of firecrackers, coming up this weekend. New Delhi tops the list almost every year of many Indian cities with poor air quality, particularly in the winter, when the burning of crop residues in neighboring states coincides with cooler temperatures that trap hazardous smoke.