Patna records ‘cleanest’ post-Diwali air quality

PATNA: For a change, Patna had the cleanest post-Diwali air quality in years with ‘moderate’ air quality index (AQI) hovering between 156 and 174 on Tuesday. As per the Central Pollution Control Board (CPCB) daily bulletin, the AQI of Patna was recorded at 172, thanks to moderate winds triggered by cyclone Sitrang in the neighboring West Bengal and other meteorological reasons.
Despite the bursting of firecrackers, many locations where continuous ambient air quality monitoring stations are installed in the city, showed the AQI reading ‘moderate’, except DRM office-Khagaul that recorded 207 AQI, which is in ‘poor’ zone. The AQI reading of Eco Park was 185, Planetarium (176), BIT-Mesra, Patna (172), Patna City (147) and SK Memorial Hall (138).

The city recorded AQI with PM 10 (particulate matter less than 10 micron) at 100 micrograms per cubic metre (g/m3) and PM 2.5 (particulate matter less than 2.5 micron) at 60 g/m on Monday. These are the main sources of pollutants in Patna.
On Diwali, the city’s AQI was 154 post the firecracker-bursting period in the night. While a day before Diwali celebrations, the air quality of Patna was in poor zone with AQI at 212.
An AQI between zero and 50 is considered ‘good’, 51 and 100 ‘satisfactory’, 101 and 200 ‘moderate’, 201 and 300 ‘poor’, 301 and 400 ‘very poor’, and between 401 and 500 as ‘severe’. Moderate pollution may cause breathing difficulties in people with lung disease like asthma and discomfort to children, elderly people and those with heart disease.
Pollution experts attributed several reasons for better air quality in Patna during Diwali and post-celebration, which included the effect of cyclonic conditions and high wind velocity in neighbouring state, awareness among masses and early celebrations compared to previous years.
Ashok Ghosh, chairman of Bihar State Pollution Control Board (BSPCB), said this Diwali was so far the cleanest in terms of air pollution, owing to early arrival of festival of light, the comparatively low bursting of firecracker compared to previous years and favourable weather conditions due to effect of cyclone in West Bengal, which helps in dispersion of suspended pollutants in the air.
“This year, we have seen people’s participation in protecting environment by celebrating green Diwali. For the last few years, we are trying to encourage people not to burst crackers and its positive impact was clearly visible this time. Besides, several measures taken by the state government under ‘Comprehensive Clean Air Action Plan for Patna’ also helps in improving the air quality of the city,” Ghosh said.
The mixing layer height, which is the height from the ground level up to which pollutants can be dispersed, was also favourable on Tuesday, which led to lesser accumulation of pollutants near the earth surface.
Arun Kumar, senior scientist and air pollution expert at BSPCB, said environment awareness among people and the windy conditions leading to lesser accumulation of pollutants helped in early dispersion of pollutants.