India, Nov. 10 -- LUCKNOW A thick blanket of acrid smoke invaded living rooms and reduced midnight road visibility to a bare 200 metres on Sunday as unbridled firecracker bursting plunged Lucknow and much of Uttar Pradesh into a post-Diwali respiratory crisis.

While winds offered the state capital a breather by Tuesday - bringing the Air Quality Index (AQI) down to a 'moderate' 172 - the preceding 48 hours left asthma patients gasping.

"Lucknow witnessed a steady deterioration in air quality over a three-day period. Its average AQI, based on readings from six monitoring stations, rose from 207 on November 7 to 233 on Diwali (November 8) and further to 245 on Monday. PM2.5 was the prominent pollutant," an expert said analysing the CPCB d...