India, March 17 -- Out of 406 cities where PM 2.5 - the fine, respirable particulate matter - is monitored, only 214 are complying with national ambient air quality standards, the Union environment ministry informed the Lok Sabha on Monday.

Kirti Vardhan Singh, minister of state for environment, made the statement while responding to questions raised by leader of opposition Rahul Gandhi on whether it was true that several cities experiencing air pollution crisis lack air quality monitoring systems.

Gandhi further asked for details of cities where air quality monitoring systems are currently operational, and the steps taken by the Central Pollution Control Board (CPCB) to expand air quality monitoring network, along with details of inter...