300 pollution sensors to patrol Delhi streets this winter

At least 300 mobile sensors will ‘move’ around Delhi’s streets this winter to keep a tab on the city’s deteriorating air quality, caused mostly by vehicular emissions on busy roads and intersections.

These low-cost pollution sensors will be developed and installed by a team of scientists from IIT-Delhi and Indraprastha Institute of Information Technology on 300 buses belonging to the Delhi Integrated Multi-Modal Transit System Limited (DIMTS).

A second team of scientists from IIT-Kanpur will analyse the data to find out how and on which roads vehicular emission was pushing up pollution levels.

These sensors will be in addition to the 38 automatic air quality monitoring stations and 10 manual stations already been set up by the Central Pollution Control Board, Delhi Pollution Control Committee and SAFAR in Delhi.

“In the first phase, we plan to install five sensors on buses. Thereafter, the number will be scaled up to 300. While initial talks have been held with DIMTS officials, bus routes and other modalities will be finalised by September-end,” said Rijurekha Sen, assistant professor of computer science department at IIT-Delhi. Sen is the principal investigator of the project.

The palm-sized low-cost sensors will able to indicate the level of particulate matter– the primary pollutants in Delhi’s air—and come fitted with cameras through which scientists will be able to see what kinds of vehicles are nearby.

Inbuilt GPS devices will tell scientists from which location the pollution data is coming so that they can identify the most polluted roads of Delhi.

The pilot project, which would be carried out between November 2018 and February 2019, is being funded by the department of science and technology. The five sensors that would be installed in October will be used mainly to train bus drivers on the do and don’ts that could hamper the reading.

“Data generated by these 300-mobile sensors criss-crossing the city, along with the existing 38 stationary automatic stations, could give us an interesting insight into the variations of particulate matter every few hundred metres or so at any given point of time. As these sensors would be installed on buses and remain close to the ground level, we will also get an idea of the actual pollution levels and vehicular emissions we are being exposed to every day,” said SN Tripathi, coordinator of the Centre for Environmental Science and Engineering at IIT-Kanpur.

A section of experts said unlike stationary monitoring stations, which cost crores of rupees but give accurate data on pollution levels, low-cost sensors cost only a few thousand rupees but their data have high error margins.

“Due to high uncertainty in measurements, the ambient air quality monitoring by sensors are only recommended for indicative purposes. This may be a good tool for survey, hotspot identification, but never recommended for regulatory monitoring,” said a senior official of the Central Pollution Control Board.

First Published: Sep 22, 2018 03:16 IST