BMC to install five new air quality monitors in city by year end

For the first time, the Brihanmumbai Municipal Corporation (BMC) is set to install and operate five of its own continuous ambient air quality monitoring stations (CAAQMS) in the city by the end of the year, as part of its mandate to increase the number of Air Quality Index (AQI) monitoring stations under the Mumbai Climate Action Plan (MCAP)

For the first time, the Brihanmumbai Municipal Corporation (BMC) is set to install and operate five of its own continuous ambient air quality monitoring stations (CAAQMS) in the city by the end of the year, as part of its mandate to increase the number of Air Quality Index (AQI) monitoring stations under the Mumbai Climate Action Plan (MCAP).

Currently, the other two bodies operating such stations in Mumbai include the Maharashtra Pollution Control Board (12 stations) and the Indian Institute of Tropical Meteorology, Pune (8 stations), which operates these under its System for Air Quality Forecasting and Research (SAFAR). (PTI)

This will take the total number of AQI monitors in Mumbai city and suburbs to 26. Currently, the other two bodies operating such stations in Mumbai include the Maharashtra Pollution Control Board (12 stations) and the Indian Institute of Tropical Meteorology, Pune (8 stations), which operates these under its System for Air Quality Forecasting and Research (SAFAR).

“The locations of the proposed monitors have not been decided but we will be installing them in places or wards which are not yet covered by the existing network. Budgetary allocations allow for five monitors, which will be made operational this year. A proposal for the same is currently being drawn up and will be shared with the municipal commissioner for approval,” said Atul Rao, who heads the BMC’s environment department, which is the nodal office for implementation of the MCAP.

Rao added that while these monitors will be operated and maintained entirely by the municipal corporation, they will be integrated with the existing network of SAFAR stations.

The MCAP, released in March this year states that the concentration of PM2.5 (particulate matter up to 2.5 micrometres in diameter) and PM10 (particulate matter up to 10 micrometres in diameter) pollutants in the city have recorded a decline over the last six years. From an annual average of PM10 level of 120μg/m3 in 2015-16, Mumbai recorded a dip to 91μg/m3 in 2020-21. This is still higher than the safe limit of 60μg/m3 prescribed by the Centre’s National Ambient Air Quality Standards (NAAQS).

For PM2.5, the concentration fell from about 80μg/m3 to 46μg/m3 in the same time period; the safe limit prescribed by NAAQS is 40μg/m3.

“The average annual concentrations of PM2.5 and PM10 have declined over the past few years but remain above the NAAQ standards. The hazardous concentrations range from 1.5 times to twice the permissible limits between 2015 to 2019, making them critical pollutants for Mumbai. Individual monitoring stations—Bandra Kurla Complex, followed by Mazgaon, Andheri and Malad—emerge as areas of high concentration based on SAFAR data,” the MCAP noted.

Experts have agreed that the MCAP accurately depicts declining concentrations of particulate matter, but have also cautioned that this overall trend provides a very limited picture of air pollution in Mumbai, given the dearth of monitoring stations across the city, and the emergence of hotspots which are not captured under the city’s existing monitoring network.

To fix this issue, the BMC has proposed to establish the country’s largest intra-city network of low-cost air quality sensors to provide real-time, localised data on air pollution. 128 devices will be installed at a density of one every four sq.km. However, the civic body has not set a deadline for the same.