Experts advise SC against smog towers
In any given hour, the amount of air passing through Delhi is over five trillion cubic metre/hour. The capacity of the smog tower in China’s Xi’an city is a fraction of that.
SARATH GUTTIKUNDA,
Care for Air scientific advisor
NEW DELHI: A group of environment experts have written an open letter to the Supreme Court requesting directions to not allow government agencies to install smog towers, on grounds of ineffectiveness and calling them a “waste of public money”.
In the open letter, experts from environment NGO Care for Air said outdoor air purifiers are ineffective and might even contribute to more pollution as its dirty filters will end up in the “already overflowing landfills”.
“We earnestly request you – please don’t direct any governments, local state or Central, to spend public money to buy expensive smog towers. These are completely useless in bringing down PM2.5 levels by any significant amount... Resources for environmental protection are scarce. Why spend them on ineffective band-aids,” the letter reads.
“Air pollution, specifically the most lethal particulate matter PM2.5 (ultra fine particulate matter with diameter less than 2.5 micrometres), can only be controlled by eliminating emissions at all known sources. Any other way is inefficient, ineffective and unscientific, and is only meant to buy time, which we are paying with our breaths every day,” the letter adds.
Jyoti Pande Lavakare, co-founder and president of Care for Air, said the letter was written as a technical advisory to the apex court so that an informed direction is given to govts. “We had a meeting with our in-house experts, who gave us the details of how outdoor purifiers do not work. Not just them but experts everywhere in the world have agreed that this is only a waste of public money,” Lavakare said.
Earlier this week, the Supreme Court had asked the Centre to take a concrete decision within 10 days on smog towers in Delhincr to combat pollution, which the court said has “shortened the lifespan of millions of citizens”.
The direction came after pollution levels in Delhi peaked after October 28. The air quality index broke the “emergency” mark on three days and the PM2.5 levels remained above the danger levels of 300ug/m3 for over 86 hours in November.
Lavakare said the NGO’S scientific advisor Sarath Guttikunda, who is also the co-director of air pollution repository Urbanemissions.info, had said that an air purification tower like the one in China’s Xi’an city can, at 100% efficiency, only purify 0.00007% of Delhi’s air.
“If you assume Delhi is like a room, the atmospheric height is at least 1km. Let us assume an average wind speed of 2 metre/ second. So, in any given hour, the amount of air that is passing through the city is over 5 trillion cubic metre/hour. The capacity of the smog tower in China is a fraction of that,” Guttikunda was quoted in the statement issued by Care for Air. He added, “Even assuming 100% efficiency of the tower all the time, the percentage of air that it could purify every hour is just 0.00007%.”
HT could not independently contact Guttikunda for comments.