Pollution crosses pre-pandemic levels

A report by Centre for Science and Environment (CSE) states Bengaluru witnessed the worst winter air pollution this year compared to its last three winters.

The New Delhi-based public research and advocacy organisation analysed the winter pollution trends in five major cities across India — Delhi, Mumbai, Kolkata, Bengaluru, Chennai, and Hyderabad.

The study found that Mumbai and Kolkata were the most polluted cities after Delhi. However, Bengaluru and Chennai saw the fastest worsening PM2.5 levels. PM2.5 is an air pollutant that is a cause for health concern when levels are high.

Earlier this year, on January 27, Bengaluru’s daily PM2.5 level hit 152 µg/m³. “This is the highest average recorded in the city since the 2019-20 winter, when the 24-hour average recorded was 101,” says Avikal Somvanshi, lead at Urban Lab, CSE. The city’s peak winter pollution was 68% higher than the average of its previous three winter peaks.

Currently, Bengaluru has 12 ambient air quality monitoring stations — BTM Layout, BWSSB Kadubeesanahalli, Bapuji Nagar, City Railway Station, Hebbal, Hombegowda Nagar, Jayanagar, Peenya, RVCE Mylasandra, Saneguravanahalli, Shivapura, and Silk Board. “Not all stations have adequate data for the previous three years and some stations didn’t have PM2.5 monitors. So keeping those aside, we evaluated the data of nine stations,” explains Avikal.

Out of the nine stations, between October and February, Bapuji Nagar was the most polluted location in the city, with the seasonal average being 64 µg/m³, followed by RVCE Mylasandra (54 µg/m³) and Silk Board (45 µg/m³). In the last five months, Bengaluru had 33 “good” AQI (Air Quality Index) days. AQI between 0-50 is said to be “good”, as per the National Air Quality Index.

As per the report, November was the worst air quality month for Bengaluru. “While cities like Delhi and Kolkata have made a consistent effort to reduce air pollution, Bengaluru on the other hand is moving in the opposite direction,” says Avikal. “This winter, the pollution was even higher compared to the pre-pandemic levels in 2019,” he tells Metrolife. Overall, this year Bengaluru’s winter air was 15% more polluted than the previous three winters.

Main culprit

Bengaluru’s evergrowing vehicular travel is one of the main reasons for the worsening pollution levels, believes Avikal. “The public transport in the city needs to be improved to reduce the rising number of private vehicles on the road. This will help reduce pollution,” adds the environmentalist.

Bengaluru has over 1 crore vehicles in an area of around 800 sq km. “An increasing number people now prefer travelling by private vehicles. This adds to the problem,” says an official at Karnataka State Pollution Control Board. In addition to this, he also attributes the increase in pollution to “prolonged winter in the city”.

“During winter, we deal with this phenomenon called inversion. During this period, the atmospheric condition gets inverted. So, cool air goes above while warm air gets trapped below. This warm air acts as a cap, trapping pollutants,” he explains.