Road Dust in Delhi

@ Hindustan Times -  “The major problem faced by Delhi is of particulate matter,” says Mukesh Sharma, a professor at IIT Kanpur and lead author of a study about the sources of air pollution. The study found that road dust makes up more than 50% of the total PM10 particles, that are 10 micrometres or less in diameter, and about 38% of PM 2.5 particles (that are 2.5 micrometres or less). PM10 and PM2.5 levels in Delhi regularly rise to five the times safety mark. According to the US Environmental Protection Agency road dust is “earthen material or dirt that becomes airborne, primarily by the friction of tires moving on unpaved dirt roads and dust-covered paved roads”. With about 33,198km roads and nearly 97,04,741 registered vehicles, the wheels on the city’s poorly maintained roads grinds up a dust storm.

Also see "what's polluting Delhi"