Urban centre covered in Smog in winter, high volume of pollution from coal fired sources in the city centre.

Every winter the National Capital Region of India is covered in a cloud of thick smog. Air quality index monitors max out with ratings of 999 and pollution reaches 50 times the level deemed safe by the World Health Organization, making breathing Delhi,s air as bad as smoking 50 cigarettes. Some of the biggest emitters are Delhi,s more than 10 million vehicles, like cars and trucks. Dust from the city,s construction boom is also a contributor to the city,s smog. Brick kilns that burn solid fuels are another factor. So is coal-fired power generation.