Amid rising pollution, CAQM mulls dust sensors on Delhi-NCR roads

Amidst growing concerns of pollution in the Capital, the Commission for Air Quality Management (CAQM), the air pollution mitigation body, is exploring the installation of dust sensors along major roads across Delhi and the wider NCR to monitor road dust, one of the city’s biggest contributors to particulate pollution.

Discussions are underway with experts to evaluate the accuracy and reliability of the technology and the stretches where it can have the most impact.

Delhi has been battling severe air quality episodes like every winter, with pollution levels frequently slipping into the ‘severe’ category.

Road dust, especially coarse particles (PM10), forms a large share of the region’s pollution load and spikes dramatically during dry, stagnant conditions.

On Friday, the Indian Institute of Tropical Meteorology’s Decision Support System estimated that the transport sector alone contributed 19.88% to Delhi’s PM2.5 concentration.

What are dust sensors & how do they work?

Dust sensors are compact devices that detect and measure particulate matter (PM) suspended in the air, typically PM10 and PM2.5, which are the most harmful to health. Most sensors use optical technology in which a beam of light is passed through sampled air, and particles scatter that light. The amount and pattern of scattered light help determine the concentration and size of particles.

Modern dust sensors can be mounted on lamp posts, traffic signals, roadside infrastructure or even moving vehicles. When placed at multiple locations, they create a high-resolution, real-time map of dust levels across road networks.

How these sensors can help Delhi check pollution

Real-time sensor data can identify dust hotspots, guide targeted action, assess the effectiveness of GRAP restrictions and construction bans by showing whether dust levels actually dip after interventions. They can also detect rule violations, including uncovered construction material, poorly maintained roads, or excessive movement of heavy vehicles. They can even support long-term planning by indicating which roads require redesigning, resurfacing or better traffic management to minimise dust resuspension.

Globally, several cities have experimented with similar systems. In Shanghai, for example, over a hundred taxis are fitted with particulate sensors that transmit real-time data on stretches with the highest dust levels.