Showers give Kolkata a break from severe air pollution in Dec – Times of India

Kolkata News

Kolkata: Rain in December ensured that the city got a break from experiencing severe pollution in what is usually one of the most polluted months of the year. There was not a single day in December 2021 when the AQI breached the 401 mark that denotes severe pollution. Usually, December and January are the worst months of the year when the air quality worsens drastically in Kolkata, sometimes even exceeding Delhi’s AQI.
In 2020, a year marked by lockdown when vehicle count on the road had dropped drastically and many commercial activities were shut for months, Kolkata had experienced only one severe day. That was recorded at the continuous ambient air quality monitoring station (CAAQMS) in north Kolkata’s Rabindra Bharati University on BT Road, which usually records the city’s worst air quality.
One of the biggest reasons for an improvement in the December ambient air in 2021 is meteorology. The late rain in early December, while being disastrous for agriculture, came as a blessing for the city’s ambient air. It not only cleansed the air of pollutants but brought one or two good (AQI:0-50) and two to three satisfactory (AQI:51-100) air days in December. This is rare.
“The impact of meteorology on the city’s air quality is overwhelming. This is why the air quality undergoes a magical transformation from the early spring. But our sustained mitigating measures are also giving very effective results. But being at the tail end of the Indo-Gangetic plain, Kolkata has its geographical disadvantage as it acts like a sink for atmospheric pollutants of the region,” said West Bengal Pollution Control Board chairman Kalyan Rudra.
However, with the drastic reduction of ‘severe’ and ‘very poor’ (AQI 310-400) days, there were rises in ‘poor’ (AQI: 201-300) days. “If the poor days also get reduced, there will be significant improvement of air quality in the city, ” said a WBPCB scientist.
The study of the AQI calendar of the city revealed the degradation of air quality was worst in Salt Lake, where very poor days increased from eight in 2020 to 15 in 2021 and poor days were marginally reduced from 18 in 2020 to 11 in 2021. Fort William experienced the best recovery of ambient air with very poor days reducing from seven in 2020 to just one in 2021 and poor days remaining constant at 13. Moderate days were also reduced from seven to four.

Source: https://timesofindia.indiatimes.com/city/kolkata/showers-give-kolkata-a-break-from-severe-air-pollution-in-dec/articleshow/89212562.cms