As Diwali approaches, Mumbai’s skyline of tall buildings is set to play a significant role in amplifying the effects of air pollution caused by firecrackers. With a mix of dense construction, limited ventilation between high-rises, and increased population density, the city’s evolving architectural landscape poses unique challenges during the festival season.
Impact of Firecrackers on Air Quality
Firecrackers, an integral part of Diwali celebrations, release harmful pollutants such as particulate matter (PM2.5 and PM10), sulfur dioxide (SO2), nitrogen oxides (NOx), and heavy metals like lead and mercury into the air. These pollutants drastically increase after firecracker bursts, leading to a significant rise in Air Quality Index (AQI) levels during and after the festival.
In previous years, AQI levels in cities like Mumbai have spiked to hazardous levels. For instance, Diwali 2023 saw Mumbai’s AQI soaring above 300 in certain areas, a level considered “very unhealthy.” Given that air pollution is already a year-round issue in the city, the introduction of high levels of pollutants during Diwali is a growing health concern.
The Role of Tall Buildings
- Restricted Airflow: Mumbai’s tall buildings, especially in areas like South Mumbai, Bandra-Kurla Complex (BKC), and Worli, form urban canyons that trap air and restrict the natural dispersion of pollutants. This leads to higher concentration levels of pollutants between buildings. The narrow corridors created by high-rises act as barriers to the natural wind flow, making it harder for pollutants to disperse.
- Thermal Inversions: Mumbai often experiences thermal inversions during the cooler months, including around Diwali. These inversions trap colder, denser air close to the ground while warmer air lies above. In areas with high-rise buildings, this effect is magnified, preventing pollutants from rising and dispersing, thus concentrating them near the ground.
- Population Density: As more people live in high-rise apartments, the use of firecrackers in and around these buildings increases. The cumulative effect of firecrackers from multiple floors leads to localized pockets of high pollution, affecting the health of residents directly. The limited open spaces in high-density regions make it difficult for air to circulate, exacerbating the pollution issue.
Predicted Air Quality Impact for Diwali 2024
Experts predict that Mumbai’s AQI during Diwali 2024 could reach hazardous levels, particularly in areas dominated by tall buildings. Current models indicate that pollution levels could rise by 20-30% compared to non-Diwali days, with localized AQI readings potentially exceeding 400 in areas with high-rise concentrations. With PM2.5 levels expected to double during the festivities, respiratory illnesses, asthma, and other pollution-related health issues are likely to spike.
Mitigating Strategies
- Green Crackers: Authorities have promoted the use of green firecrackers which reduce emissions by 30%. However, their adoption has been slow, and their impact is limited when used in densely populated areas surrounded by high-rise buildings.
- Improved Ventilation in Building Designs: Urban planners and architects in Mumbai are focusing on ventilation-friendly designs for future buildings to improve airflow between high-rises. However, these efforts will not mitigate the immediate risks for Diwali 2024.
- Government Interventions: Local authorities could enforce time restrictions on firecracker use, promote community firework events in open spaces, and ramp up awareness campaigns about the health impacts of air pollution during the festival.
Conclusion
Mumbai’s tall buildings are likely to exacerbate the negative environmental impact of Diwali firecrackers, creating pollution hotspots and heightening health risks. Without coordinated efforts from both the public and the government, the combination of urban architecture and festive celebrations will continue to pose significant air quality challenges for the city. Small measures, such as using green crackers and restricting firecracker use, while helpful, may not be enough to mitigate the compounded effects brought on by dense, high-rise urban landscapes.
