Over several years, Delhi has turned into one of the most polluted cities in India. With an average Air Quality Index (AQI) of above 250, the average PM2. 5 concentration was more than 200 micrograms per cubic metre in 2020. Delhi’s atmosphere is three times worse than the safe standard. High quantities of sulfur dioxide, nitrogen oxide, and carbon monoxide in the air have only worsened the localite’s respiratory strength.
To combat this, Delhi government installed a 24-metre tall smog tower at Baba Kharak Singh Marg in Connaught Place. The tower acts as a large-scale air purifier that will help purify 1,000 cubic meters of air in a second. The tower supposedly can absorb polluted air from within a km and can purify air through the 40 fans attached to its lower structure. After purification, the tower recirculates air into the atmosphere. These towers were built by Tata Projects Limited (TPL) with technical assistance from IIT Bombay and in collaboration with IIT Delhi.
AAP frontman Arvind Kejriwal who inaugurated the tower, claimed it to be the first of its kind within the country. However, fact-checking sources have revealed the prior installation of similar towers – a 20-ft tall smog tower installed by East Delhi MP Gautam Gambhir in January 2020 in Lajpat Nagar’s Central market. This smog tower can clean 2,50,000 to 6,00000 cubic meters of air every day.
Nutan Labs, a nanotechnology-based Bengaluru startup has also installed a similar tower within the city in March.
However, there is no evidence of smog towers curbing pollution within the country. “While smog towers might appear as a visible solution to air pollution, there is no scientific evidence — even globally — to support that they can filter outdoor air effectively,” said Tanushree Ganguly, program lead at the Delhi-based Council on Energy, Environment, and Water (CEEW).aid
Short-term relief from air pollution will not be feasible in the long run. These towers are expensive and lack enough evidence to support their durability and potency. Experts have directed state governments to address the root of pollution to solve the problems.