Sunday, Feb 05, 2023

Smog towers, and the fog of pollution fight

Anumita Roychowdhury writes: As always, winter smog is a combined impact of inversion and calm winds, high local pollution and constant intrusion of pollution from neighbouring regions, including seasonal biomass burning.

An aerial view of the smog tower at Anand Vihar Metro Station in New Delhi. (Express Photo by Tashi Tobgyal)

Written by Anumita Roychowdhury

Delhi is wrapped in the season’s first severe smog, which is expected to be one of the longest smog episodes in recent times. Since Diwali, the Air Quality Index has remained elevated in the ‘severe’ category. In response to this health emergency, the Supreme Court has asked the city for an immediate response plan or a lockdown.

As always, winter smog is a combined impact of inversion and calm winds, high local pollution and constant intrusion of pollution from neighbouring regions, including seasonal biomass burning.

This seasonal scourge has once again raised questions about the city’s preparedness in controlling the killer smog. This time too, temporary measures have been routinely announced, targeting dust pollution, garbage burning, decomposition of paddy straw, monitoring of pollution hotspots, and vehicular pollution.

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Also included are the two giant smog towers in Anand Vihar and Connaught Place to purify dynamic outdoor air within a 1-km radius. Anand Vihar is still among the top five worst polluted locations in the city this winter.

However, as of now, there is no assessment available on the effectiveness of these systems. How can these expensive devices clean up the ‘ambient air’, when the total air exchange transports billions of cubic metres of air per day, bringing in more pollution? How can they make a dent in the 3,200 tonnes/year of total particulate load generated in the city (as per a 2018 study by the TERI and Automotive Research Association of India)?

Every year, the official focus routinely shifts to temporary measures, when enforcement itself is the weakest link. This year too, Central Pollution Control Board (CPCB) data show that of the total public complaints received during the second half of October, the departments concerned could attend to only 11 per cent of all incidents. Emergency measures thus become necessary during smog episodes.

Walk the talk


The seasonal ‘noise’ about pollution has to bring the focus back on the effectiveness of solutions to meet time-bound, monitorable and verifiable clean air benchmarks.

While steps taken so far in Delhi have bent the long-term pollution curve, as is evident in the CPCB data, it is not enough. More aggressive measures are needed. Delhi has closed all coal power plants, expanded natural gas in industry, banned dirty fuels, moved public transport and local commercial vehicles to CNG, banned old vehicles, and restricted truck entry.

But big gaps in action remain. The continuous estimates of contribution of eight different local sources of pollution to Delhi’s air quality, done by the Indian Institute of Tropical Meteorology (IITM), Pune, has established that this winter, vehicles have emerged as the biggest contributor to air pollution in the capital.


Clearly, the explosive motorisation (1.3 crore vehicles in one city), coupled with inadequate public transport services, the huge deficit in walking and cycling infrastructure, and lack of restraint measures in terms of parking policy and low emissions zones, has increased emissions from urban commuting.

Even though the city has expanded its use of natural gas in industrial estates and notified a clean fuel policy, implementation across all industrial units in municipal areas and unauthorised areas has been ineffective. The city also needs efficient collection of industrial waste to ensure the waste is not burnt. In fact, all industrial units need to be mandated to display ‘consent to operate’ as well as be transparent about their emission management systems.

While every winter the focus is on preventing burning of waste in the open, the city has done little to improve the collection and processing efficiency of waste. Out of the 11,144 metric tonnes per day of total municipal solid waste generated in Delhi, only 47 per cent is processed and reutilised. More than half goes to landfills, making them prone to spontaneous fires.

On the other hand, in the construction sector, Delhi has set up more processing capacity of construction and demolition waste than what it generates. According to the Delhi Pollution Control Report, the total generation is 3,711.64 tonnes per day against the processing capacity of 4,150 tonnes per day. But at the ground level, due to inefficient collection, the entire waste does not reach the processing plants. This also requires a mandate for all construction agencies to utilise the recycled aggregate and material (like the way the new building of the Supreme Court has done).

The IITM estimates also show that pollution from household sources is substantial. This requires clean fuel access to all poor households and open eateries.


Clearly, all departments in each sector have to map out the gaps in the current infrastructure and systems to set targets for time-bound action. These multi-sector solutions, department-wise responsibilities and accountabilities, and budgets should have been worked out and provided for way in advance to enable a massive transformation this year.

The writer is Executive Director, Research and Advocacy, Centre for Science and Environment, New Delhi

First published on: 14-11-2021 at 03:44 IST
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