Drones spraying mist new stunt to check bad air in Delhi

Gopal Rai said more than 200 anti-smog guns are deployed across Delhi, spraying water along roads to reduce airborne dust

The Delhi government on Friday tested “drone-based mist spraying” at Anand Vihar, one of the city’s pollution hot spots, sending up a device with a capacity to hold as much water as a typical household water bucket.

Delhi minister Gopal Rai at the drone trial run. (PTI)

During the demonstration, environment minister Gopal Rai said more than 200 anti-smog guns are deployed across Delhi, spraying water along roads to reduce airborne dust.

“Hot spots have worse air quality than the rest of the city. The trucks (mounted smog guns) are sprinkling water in areas which are accessible but drones are being used in places that trucks cannot reach. A demonstration was carried out today and three more drones are being procured by the Delhi Pollution Control Committee (DPCC). We will experiment and study the impact in the coming days,” he added.

“Each drone can carry 15 litres of water. After sprinkling water, it will come down and again refill to sprinkle water at inaccessible sites. Today we have carried out a demonstration. DPCC has floated a tender for three drones to be used in different hot spots. The government will decide the future of the project based on study results,” he added.

Experts, however, have questioned the efficacy of such measures.

“Using drones to sprinkle water over pollution hotspots may seem innovative, but it has limited impact on air quality. Water sprinkling primarily settles larger PM 10 particles, with minimal effect on finer and more dangerous PM 2.5 particles, which can penetrate deep into the lungs and bloodstream. Logistically, the approach is also inefficient; a single drone carrying 15 litres of water is unlikely to cover enough area or provide lasting impact, especially in densely polluted areas,” environmentalist Bhavreen Kandhari said.

On October 25, the government had surveyed the Wazirpur hot spot in north Delhi with the help of a drone in a pilot project. The drone was operated at a height of 120 metres from the ground, covering a radius of 200 metres at an open ground in Wazirpur, in presence of Rai. Experts, on the other hand, said funds could be used for other schemes that target pollution at its source.

In 2018, DPCC and the Central Pollution Control Board (CPCB) had identified 13 pollution hot spots in Delhi based on their annual PM2.5 concentration. This includes Anand Vihar, Mundka, Wazirpur, Jahangirpuri, RK Puram, Rohini, Punjabi Bagh, Okhla, Bawana, Vivek Vihar, Narela, Ashok Vihar, and Dwarka.

On October 15, HT had reported that the Delhi government was looking to procure mist-spraying drones for pollution hot spots this winter. Monitor air pollution through drones is part of the government’s 21 point Winter Action Plan, announced on September 25.