Authorities in the Indian capital, Delhi, have shut all schools and colleges indefinitely amid the worsening levels of air pollution. Construction work has also been banned until 21 November but an exception has been made for transport and defence-related projects. Only five of the 11 coal-based power plants in the city have been allowed to operate. A toxic haze has smothered Delhi since the festival of Diwali. The levels of PM2.5 – tiny particles that can clog people’s lungs – in Delhi are far higher than the World Health Organization’s (WHO) safety guidelines. Several parts of the city recorded figures close to or higher than 400 on Tuesday, which is categorised as “severe”.(BBC)…[+]