Delhi dwellers losing 7.8 years to PM2.5 pollution: Report

New Delhi
Delhi residents are losing 7.8 years of their life expectancy to increased PM2.5 concentration, according to a report published by a US-based research institute, which said the loss can be mitigated by reducing the level of the pollutant to the World Health Organization (WHO) standard of 5 micrograms per cubic metre (µg/m3)
The report, on Air Quality Life Index (AQLI) published by the Energy Policy Institute at the University of Chicago (EPIC) on Wednesday is based on analysis of 2022 pollution data. It said that even containing the level of PM2.5 — particulate matter having diameter less than 2.5 microns, a major pollutant in Delhi — to the national standard ormore lenient level of 40µg/m3 can increase life expectancy of 18.7 millionDelhi residents by 4.3 years.
The AQLI is a pollution index that quantifies the causal relationship between long-term human exposure to air pollution and life expectancy. The life expectancy calculations made by AQLI are based on a pair of peer-reviewed studies. By comparing two subgroups of the population that experienced prolonged exposure to different levels of particulate air pollution, the studies were able to plausibly isolate the effect of particulate air pollution from other factors that affect health.
To be sure, Delhi’s average PM2.5 concentration in 2022 was 84.3µg/m3. This made Delhi the most-polluted state or Union territory in the country, the report said.
According to WHO, life expectancy at birth in India was 67.3 years in 2021. This is up by nearly five years from the average life expectancy of 62.1 years in 2000.
“If all of India were to reduce particulate pollution to meet the WHO guideline, residents in Delhi—India’s capital and most populous city—would see the maximum benefits, with its residents gaining 7.8 years of life expectancy. In North 24 Parganas – a district in West Bengal and the country’s second most populous district, residents would gain 3.6 years of life expectancy,” said report on Tuesday.
Delhi consistently ranks among the world’s most polluted cities each year, impacted by a cocktail of pollutants that are at their peak in the winter months from November till January. Pollution in Delhi spikes following the harvesting of crop in the northern plains, which often clashes with Diwali, leading to a mixture of smoke from residue burning and firecrackers hanging over the capital’s air for weeks. Other than these, Delhi is also impacted by localised sources such as industries, vehicles and burning of waste, keeping levels of pollutants well above permissible standards.
The report found that after Delhi, Uttar Pradesh was the most polluted, with an annual average PM2.5 level of 65.5µg/m3, with residents of the state expected to gain 5.9 years if the WHO standard is met and 2.5 years if the national standard is met. For Haryana, the corresponding figures were 5.2 years and 1.8 years, respectively.
The report, despite showing Delhi residents losing considerable years in terms of life expectancy, nevertheless posits an improvement from a previous study done on 2021 PM2.5 level.
Last year’s EPIC report, based on 2021 data, revealed Delhi’s PM 2.5 level was 126.51µg/m3 — up from the level of 111.6µg/m3 recorded in 2020. The previous report posited an increase of 11.9 years in life expectancy if WHO standards were met and 8.5 years if national standard of 40µg/m3was met.
The report found that not just Delhi, but other states and UTs also showed an improvement in 2022. The average PM2.5 concentration for India reduced from 49µg/m3 in 2021 to 41.4µg/m3 in 2022, which is still over eight times the WHO standard, but close to the national standard.
“If these reductions are sustained, an average Indian is likely to live nine months longer compared to what they would have if they were exposed to levels similar to the last decade. Further, if pollution in India met the WHO guideline, Indian citizens could gain an additional 3.6 years onto their life expectancy,” the report said.
Tanushree Ganguly, director of AQLI, said that over the years, Delhi’s PM2.5 concentration has largely remained over 100 µg/m3, barring 2020, when Covid-19 curbs kept levels low.
“In 2022, PM2.5 levels in Delhi were 17% lower than 2021 and the average of 2016 to 2021. While it is difficult to conclusively separate the effects of weather from policy implementation in explaining this decline — especially since the entire South Asian region, including Bangladesh, Nepal, and Pakistan, reported reduced particulate concentrations — sustaining these reductions in Delhi could increase average life expectancy in the city by 1.6 years,” she said.
Environmental activist Bhavreen Kandhari said even if there is an improvement in relation to 2021, 7.8 years was a significant sum of years being lost to bad air. “It is important the national standards are also brought down, as the WHO standards are closer to clean air. We still need to work hard to bring down the years being lost and that can only be done if both state and the Centre acknowledge the health risk associated with air pollution,” she said.
Anumita Roychowdhury, executive director, research and advocacy at the Centre for Science and Environment (CSE), said Delhi still has a long way to go to bring down its PM2.5 level, but an aggressive and stringent approach towards electrification, integrated public transport and low-emission zones with cycling or walking facilities could help in this regard.
“We also need to improve our waste management, which means 100% waste collection, segregation and processing. This eliminates burning of waste and landfills. We also need to replace dirty fuels for cooking with cleaner fuels and implement clean energy across all sectors,” she said.