An analysis conducted by Respirer Reports, a part of Respirer Living Sciences in Pune, assessed the levels of carcinogenic PM2.5 concentrations, representing the toxicity in the air, in six major Indian capital cities facing air pollution challenges: Delhi, Mumbai, Bengaluru, Kolkata, Lucknow, and Patna from 2019 to 2023.
Mumbai pollution: City wakes up to smog, poor visibility
While both Delhi and Lucknow experienced worse air quality levels than Mumbai, they showed signs of improvement during this period. In contrast, Mumbai, along with Bengaluru and Kolkata, witnessed a steady rise in pollution levels, indicating a deterioration in air quality.
In the January–March quarter, Mumbai’s air quality consistently worsened, with PM2.5 levels increasing from 50.2 µg/m3 in 2019 to 80.6 µg/m3 in 2023, a significant 60.5% jump. During the October to December season of 2022, the average PM2.5 concentration in the air increased compared to the same period in 2021 but was slightly lower than that of 2020. These findings underscore the urgent need for Mumbai to intensify its efforts to reduce carbon emissions.
Notably, on a recent Tuesday, Mumbai’s air quality slipped into the ‘moderate’ category with an AQI of 150 for the first time in nearly eight months. Colaba emerged as the most polluted location in the city, with an air quality index (AQI) of 318, categorized as ‘very poor.’ Other monitored locations, such as Navi Mumbai, Malad, Mazagaon, and Andheri, recorded AQI values ranging from 161 to 201, all within the poor to moderate category. Factors contributing to this decline include reduced wind speed and high humidity.
It’s important to highlight that the annual and quarterly PM2.5 levels in these major cities, including Mumbai, since 2019 have consistently exceeded the CPCB’s ‘good’ level of 30 µg/m3 and WHO’s safe guideline of 5 µg/m3. The report’s data is based on information obtained from the Central Pollution Control Board (CPCB) website as of September 30, 2023, using daily and annual averages from government air quality monitoring stations.
Aarti Khosla, director of climate trends, emphasized the need for deeper research to understand the factors contributing to air quality improvements, such as emissions sources and meteorological conditions. Vehicular pollution, construction site dust, garbage burning, and industrial emissions are cited as significant contributors to Mumbai’s pollution. The city’s AQI typically worsens after the monsoon due to a combination of high moisture, low wind speed, and humidity, leading to the lingering presence of smoke and dust in the air, especially during the winter months.
In some instances between November 2022 and March 2023, Mumbai’s AQI even surpassed that of Delhi, a city known for its severe pollution issues, underscoring the gravity of the air quality challenge faced by Mumbai. Addressing this issue requires a scientific, sustained approach, including adopting an airshed approach to air quality management.