Winter Air Pollution in Maharashtra and Gujarat Reaches a Four-Year High

A new analysis by the Centre for Science and Environment (CSE) has found that the winter of 2022-23 in Maharashtra and Gujarat was the most polluted in the last four years. The analysis, conducted between 1st October 2022 and 28th February 2023, reveals that winter pollution typically sets in during late November and early December when cooler and calmer conditions trap local pollution.

Executive Director, Research and Advocacy, CSE, Anumita Roychowdhury, stated that the rapid increase in winter PM2.5 levels in both big cities and smaller towns reveals the spread of air pollution in this region. She believes that the increase in local pollution in developing cities, coupled with regional influence, is worsening the challenge and overpowering the advantages of natural ventilation from the coastal climate. Roychowdhury called for an immediate roadmap to control pollution from key sources across the region.

Although Gujarat has higher pollution levels in absolute terms, Maharashtra’s levels are increasing more rapidly. Mumbai and Navi Mumbai are the most polluted locations in the region, while Vapi and Surat are among the most polluted locations in Gujarat. Nagpur recorded the highest increase in pollution, with a 105% rise compared to the previous winter.

The analysis forms part of the third edition of Urban Lab’s Air Quality Tracker Initiative, which started in the winter of 2020-21. The analysis is based on real-time data from air quality monitoring stations in these two states, and the winter period is defined as the time between 1st October 2022 and 28th February 2023.

Key Findings of the CSE Analysis

The average PM2.5 concentration across cities in the west stood at 69 microgramme per cubic metre (µg/m³) this winter. This concentration is 10% higher than the mean of the previous three winter seasons, and the daily peak for the region this winter happened on 24th October 2022, the day after Diwali, when the level was 127 µg/m³.

Winter pollution has been rising in Maharashtra on a yearly basis and stood at 66 µg/m³ this winter. Gujarat was the more polluted of the two states in absolute terms, with a winter average of 73 µg/m3. Gujarat registered an increase of 6% compared to the mean of the previous three winters, while winter pollution was on a decline in Gujarat since 2019 but spiked up this winter.

Gujarat had its daily peak of PM2.5 at 158 µg/m3 on 24th October 2022, which was the highest regional peak in the last four years and was 19% higher than the mean of the previous three winter peaks. Maharashtra’s daily peak PM2.5 happened on 2nd December 2022.

Conclusion

The analysis reveals that winter pollution is a significant challenge for cities in Maharashtra and Gujarat, with pollution levels reaching a four-year high. The increasing local pollution in developing cities and regional influence is making the challenge worse, overpowering the benefits of natural ventilation from the coastal climate. It is important to establish an immediate roadmap to control pollution from key sources across the region to tackle this issue.