The air quality of India’s financial capital, Mumbai, has deteriorated in the last few weeks due to weather conditions and emissions from various sources. Dust emissions from construction activities have surfaced as a key contributor. Construction activities play a significant role in increasing the levels of PM10 – a pollutant with a diameter of 10 microns or less (one-tenth the diameter of human hair) – that can enter human lungs. In the last few weeks, PM 10 has been consistently responsible for the poor readings in the air quality index in Maharashtra’s capital.
Mumbai is undergoing a massive transformation which requires the construction of infrastructure. A review of recent reports shows that construction activities in the Brihanmumbai Municipal Corporation (BMC) area have increased by 68 per cent since 2022 and 142 per cent compared to 2021. In the Mumbai Metropolitan Region (MMR), it has grown 36 per cent since 2022 and 98 per cent since 2021. With over 11,000 private building construction sites and public projects such as the Metro, Mumbai Trans Harbor Link (MTHL), Navi Mumbai Airport, roads and other utility infrastructure, the construction sector has emerged as a major contributor to dust emissions in the city.
Demolition and construction processes involve hammering, crushing, cutting, trimming, drilling, grinding, mixing, excavating, dumping, and transporting – vertically or horizontally – throughout the day. This leads to fugitive emissions, which, when not controlled, get dispersed in the atmosphere and deposited on surrounding surfaces. These settled dust particles get re-suspended due to wind flow, human activities, traffic movement and other external factors. When such construction sites are in residential areas, these emissions pose a threat to the health of vulnerable populations, including children, the elderly and people with lung diseases and associated comorbidities.
At the same time, managing construction dust offers a huge opportunity for reducing air pollution in Mumbai. We need to imagine a transition of the building industry from the current construction technologies and practices to clean-air-oriented practices where controlling emissions is at the centre of planning and execution.
Some measures can enable this transition. Mapping pollutant sources in air sheds (an area whose topography and meteorology limit the dispersion of pollutants) and creating detailed emission inventories can help Identify hotspots. This can then inform a long-term coordinated action approach. An institutional setup to enable regional coordination among cities holds the key. Engagement with all stakeholders in the ecosystem could help advance the agenda.
Standard operations procedures for builders and mitigation measures to help reduce emissions from construction activities can be mandated in regulations. The BMC is doing this to an extent by framing a mitigation plan. However, specific guidelines need to be established for large-scale infrastructure projects. The BMC’s guidelines should be adopted by other municipal corporations and development authorities in the Mumbai Metropolitan Region.
The guidelines need to be enforced. This is where multi-stakeholder engagement becomes critical. The BMC has planned a task force to ensure enforcement. It needs to get access to real-time data. For this purpose, air quality data sensors can be installed at construction sites and connected to a central server at the municipality’s office. This can help target high polluters.
Merely framing guidelines for builders may not yield results immediately unless they understand the new procedures. Builders, contractors, site engineers, architects and project management consultants need to be sensitised and the information required to implement the mitigation measures must be clearly communicated to them. This would require a commitment from all stakeholders to participate in learning activities.
Many of the products required to capture dust emissions from construction activities are not commonly available in the market. For instance, machines that simultaneously absorb dust while also serving cutting purposes are not commonly used in construction — such products, however, are used in industries. BMC needs to catalyse innovation and ensure market-ready construction technologies and equipment to reduce emissions from the sector. Builders and construction sites that are implementing mitigation measures should be recognised and their practices should be shared widely so that others can follow their lead.
As Mumbai undergoes an infrastructure transformation, a blanket ban on construction when air quality worsens is likely to come at an economic cost – the construction industry is the second largest contributor to India’s GDP. The implementation of many of these measures will have to be gradual. In the first year, the municipality can focus on identifying solutions and building strategies towards achieving these goals. By the following year, stricter enforcement measures should be in place. Mumbai’s vibrant real estate industry can support the city in becoming a leader in mitigating air pollution while also contributing to its economic growth. A clean construction transition that takes environmental considerations into account could pave the way for sustainable development in Indian cities.
Sree Kumar Kumaraswamy is the Program Director, Clean Air at WRI India, and Madhav Pai is the CEO at WRI India. Views are personal
