The green panel was hearing a matter where it had taken cognisance of the online air quality bulletins of the Central Pollution Control Board across different cities from October 20 to November 1."The chief secretaries of the states where the cities' AQI has dipped to severe, very poor and poor, are directed to take immediate remedial action and submit action taken report before the tribunal on on or before the next date of hearing (Nov 10)," the tribunal said.