Chennai: To monitor air quality in real time without spending crores on expensive equipment, the Tamil Nadu Pollution Control Board (TNPCB) has decided to install 80 digital low-cost monitors across the state. The bulk of these monitors will be installed in cities.These monitors will be different from the continuous ambient air quality monitoring (CAAQM) system that uses high-end equipment and is more accurate. “The locations haven’t been decided yet. Though the accuracy will be slightly lower, it is cheaper and therefore more can be procured and installed at several locations. Naturally, the air quality index (AQI) will be representative of more locations from the city, and we can get a near-accurate depiction of the pollution level,” a senior official with TNPCB said.While a single CAAQM unit costs about ₹1-2 crore, including installation and annual maintenance, a digital monitor can be installed for less than ₹10 lakh. Additionally, the equipment uses sensors and Internet of Things (IoT)-based monitoring, which requires less maintenance.“We can have nearly 10 digital monitors for the same cost as one CAAQM. The sensors will also be able to track humidity and suspended particulate matter levels,” the official said. The environment department has allocated ₹8 crore towards this initiative.TNPCB chairperson Anurag Mishra said the data provided by the sensors will be relayed live on the website.As of 2024, Tamil Nadu had 34 CAAQMs. Eight of these are in Chennai, including those installed by the Central Pollution Control Board. However, real-time data on the website is only from 11 of them. Environmentalists welcome the move to increase the number of stations, but say accuracy shouldn’t be compromised, especially in cities such as Chennai — which ranked 35 out of 48 cities in the clean air survey report released by the Union ministry for environment on Monday.“The govt must ensure that the monitors are installed in critically polluted places. To compensate for reduced accuracy, the machines must be able to capture what type of pollutant is prevalent in the area,” V N Prabhakaran, environmental engineer, Poovulagin Nanbargal.
