Toxic smog smothering India's capital smashes WHO limit

Cooler temperatures and slow-moving winds trap deadly pollutants. At dawn on Wednesday, "hazardous" pollutant levels in parts of the sprawling urban area of more than 30 million people topped 806 micrograms per cubic metre, according to monitoring firm IQAir. That is more than 53 times the World Health Organization recommended daily maximum of fine particulate matter -- dangerous cancer-causing microparticles known as PM2.5 pollutants that enter the bloodstream through the lungs. Many in the city cannot afford air filters...