LUCKNOW, Nov. 7 -- A day before Diwali, when the use of firecrackers is comparatively lower than on the festival day, Lucknow's air quality deteriorated to the "poor" category on Saturday after remaining moderate for two days, hinting at more polluted days on and after Diwali. The data is based on the Central Pollution Control Board's (CPCB) 4 pm bulletin.

The last time the AQI had entered the poor category was on November 4, when it stood at 223.

Experts expect the AQI to cross the 300 mark and enter the "very poor" category on Diwali night, making the city's air quality worse. They also said increased vehicular movement due to the Diwali rush was adding to pollution.

Of the six live monitoring stations set up by the Uttar Pradesh Pol...