Proven solutions rooted in science, not unproven technological improvements, will reduce air pollution
Two new smog towers have been inaugurated recently in Delhi. Bengaluru and Chandigarh have also installed smog towers this year. Mumbai’s Clean Air Plan indicates a financial requirement of ₹25 crore to set up air filtration units at major traffic intersections in the city. While these efforts indicate that governments are taking cognizance of air pollution, the deployment is often driven by symbolism rather than science. For example, the Delhi government claims that the newly installed smog tower in Connaught Place can reduce air pollution levels by up to 80%. But there is no scientific evidence of smog towers or any other outdoor air filtration units improving air quality in cities. The smog tower installed in Xi’an, China and another one in Beijing did not prove effective nor was it extended.
Smog towers create the illusion of progress towards cleaner air and divert millions of public money away from proven solutions. Moreover, they mislead policy makers and citizens by diverting attention from sectors demanding immediate action. Therefore, governments investing in external filtration systems should postpone their deployment plans.
In addition, data on the effectiveness of newly installed smog towers should be made publicly available for independent evaluation. Unless there is scientific consensus on their effectiveness, every new tower installed is a breach of taxpayers’ money and citizens’ trust.
what can we do
In the meantime, governments should increase investment in proven solutions to reduce air pollution. First, policymakers should expand air pollution monitoring to areas with limited or no air quality monitoring and strengthen forecasting capacity in cities. Of the 132 cities in the country that currently do not meet the national ambient air quality standards, 75 do not have a single real-time monitoring station. For areas with monitoring infrastructure, alternatives such as low-cost air quality monitors in combination with satellite observations should be explored to plug existing data gaps. Also, cities should strengthen their air quality forecasting systems by collaborating with scientific institutions to be transparent about their perspectives and findings. These forecasts should be used to implement preventive measures such as travel restrictions, halting business activities or encouraging work from home on potentially high pollution days.
Second, city-level emissions inventories should be updated periodically. Until last year, more than 75% of our city’s clean air plans did not contain critical information about emissions from various pollution sources. These data are important to identify the major sources of air pollution and to design effective clean air plans according to the local context. While many academic institutions conduct emission inventory and source segmentation studies, these studies should not become a one-time exercise.
Third, targeted efforts should be made to improve air quality for urban slum dwellers who do not have access to clean cooking energy. In a recent study, we found that nearly half of urban slum households in six states still depend on biomass and other polluting fuels for their cooking needs. In addition, household emissions tend to increase during the winter, especially when the need for fuel for non-cooking tasks such as space heating increases. This increases exposure to indoor air pollution and poses a health risk. Therefore, policy makers should focus on providing LPG connections to these households along with ensuring continued use of LPG as the primary fuel.
Lastly, and most importantly, cities must strengthen their enforcement by investing in people and systems that can monitor around the clock both serious and relevant pollutants. India is witnessing a growing democratic demand for clean air. But this cannot be accomplished with unproven technical improvements. Instead, we must strictly follow the solutions rooted in science to bring back blue skies.
Tanushree Ganguly is Program Lead and Mihir Shah is Strategic Communications Lead at Council on Energy, Environment and Water
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