Mumbai gets sensor-based monitors as low cost air monitoring feasibility study begins

The sensors will monitor particulate matter (PM10, PM2.5), ozone, oxides of nitrogen (NOx), and sulphur oxides (SOx).

Installations of low-cost sensor based air quality monitoring equipment has been completed across 15 locations in Mumbai for the first-of-its kind study in India using this technology to accurately measure harmful pollutant concentration in the air, the Maharashtra Pollution Control Board (MPCB) said.

Low-cost monitoring sensors measure ambient air quality based on light scattering technology using much smaller equipment as compared to existing air quality measuring technology. (HT PHOTO)

Low-cost monitoring sensors measure ambient air quality based on light scattering technology using much smaller equipment as compared to existing air quality measuring technology.

In July, MPCB and the Indian Institute of Technology, Kanpur (IIT-K) signed a memorandum of understanding (MoU) to undertake the sensor technology assessment between November 1, 2020 and May 31, 2021.

Readings from the air quality equipment will begin being relayed to MPCB and IIT-K servers from November 1. “The installation of the monitors has begun. Now we are awaiting the data acquisition for final project implementation within a couple of days. Once data starts flowing into MPCB or IIT-K servers, it will help us understand and develop the interfaces. We are planning a formal launch soon,” said Sudhir Srivastava, chairman, MPCB.

“The basic idea is to get a sense of the liability, accuracy, and reproducibility of the result of these monitors. It will also help us understand the effectiveness of existing CAAQMS data. Once the feasibility is confirmed, it will be scaled across the state,” said Srivastava.

Such monitors would be rolled out across 18 non-attainment cities in Maharashtra to identify pollution hotspots through hyper-local air monitoring, source distribution and associated health impacts, he said.

Manual monitors to measure air quality have been used since 1984-85 by the Central Pollution Control Board (CPCB), which was later renamed the National Air Quality Monitoring Programme (NAMP) network. It presently consists of 793 operating stations covering 344 cities and towns in 29 states and six union territories in India. The manual method involves analysis of pollutants measured once every six days where data is transferred manually for overall assessment, and the cost is Rs. 8 lakh per station per annum including purchasing cost, maintenance, and number of pollutants measured (according to MPCB). CAAQMS monitors cost Rs. 1.5 crore per station per annum including all additional costs and are automatic monitors providing real-time data that is easy to interpret.

Low-cost monitors are bought for Rs. 50,000 to Rs. 2 lakh (including maintenance) based on the number of pollutants they measure, said independent researchers.

“For hyper local monitoring, these sensors are indispensable. However, one is required to do extensive validation for accuracy and precision of sensor data over a wide range of meteorological and environmental conditions,” said Professor SN Tripathi, head of civil engineering, IIT-K and apex committee member, National Clean Air Program.

“This is the first experiment in India which is currently being conducted in collaboration with MPCB covering the entire CAAQMS or government network of the greater Mumbai region. This will enable us to conclusively determine the accuracy and stability of sensor data and will pave the way for large-scale sensor deployment in Maharashtra in particular and India in general,” Tripathi said.