Even three days after Diwali, the air quality in Chandigarh remained “poor”.

The city recorded air quality index of 259 on Wednesday afternoon. “Poor” quality air could cause breathing discomfort to most people on prolonged exposure.

An AQI between 0-50 is considered good, 51-100 satisfactory, 101-200 moderate, 201-300 poor, 301-400 very poor and 401-500 severe.

As per the data observed at continuous ambient air quality monitoring station (CAAQMS) at Panjab University Sector 25 here, the PM 2.5 levels stood at an average of 259 µg/m and maximum of 331 µg/m on Wednesday while PM10 levels were 167 µg/m on an average and maximum of 272 µg/m in the city.

The permissible limit for PM2.5 is 60 µg/m3while its 100 µg/m3 for PM 10. Both PM 10- (particulate matters with diameter of 10 microns or less) and PM2.5 (particulate matters less than 2.5 microns)-form of air pollution, can cause severe health problems.

The concentration of sulphur dioxide (SO2) and NOx, however, remained below the permissible levels.

Meanwhile, the high pollution level has also led to low visibility in the city.

Surender Pal, Director Meteorological Department, Chandigarh said that due to no movement in the air, stubble burning in neighboring states and high relative humidity, the air quality remains poor in Chandigarh even three days after the festival of Diwali.

Due to these factors, visibility has also been affected in Chandigarh, he said.

He also said that the western disturbances are approaching the region and light rainfall is expected in Punjab on November 2 and 3. The air quality in the region is likely to improve after rainfall, he added.

Notably, the air quality index was recorded above 300, which is categorized as “very poor”, at various locations in the city on Diwali, October 27.

As per the data with Chandigarh Pollution Control Committee, the air quality index (AQI) was 371 in Sector 22, 352 in IMTECH-Sector 39, 341 in CAAQMS Sector 25, 280 in PEC Sector 12 and 247 in Sector 17 on Diwali.

Following Court directions, bursting of fire crackers was only permissible between 8 PM to 10 PM on Diwali. But despite restrictions on bursting the crackers and awareness campaigns not to use crackers, PM 2.5 and PM10 level — particulate matter —was double than what it was last Diwali in the city.

The PM2.5 levels stood at 212 µg/m3 in Sector 22 (residential), 187 µg/m3 in Sector 39, 114 µg/m3 in Sector PEC -12, 173 µg/m3 in CAAQMS Sector 25 and 104 µg/m3 in Sector 17 on the night of Diwali.

As far as PM10 is concerned, it was also recorded above permissible limits in the city as PM 10 value of 280 µg/m3 was recorded in Sector 22, 173 µg/m3 in Sector 17, 141 µg/m3 in PEC -12, 240 µg/m3 in IMTECH -39,  236 µg/m3 in CAAQMS (Sector 25).