Cost of breathing bad air? 11.9 years in Delhi and 11.2 years in Gurugram: Study
Delhi is the most polluted megacity in the world with Noida and Gurugram next in line with average loss of life of more than 11 years
People living in Delhi stand to lose nearly 12 years of their lives because of air pollution, the worst in all megacities of the world, a global report released on Tuesday found, with the Capital’s satellite cities of Noida and Gurugram next in line with average loss of life of more than 11 years.
The average Delhi resident might lose 11.9 years of their lives on an average to air pollution, the Air Quality Life Index 2023 report of the University of Chicago’s Energy Policy Institute (EPIC) has stated.
The report, which calculated the loss in life expectancy globally across 245 countries and territories, analysed the annual average PM2.5 levels recorded across different Indian cities and states, with 2021 taken as the base year. The data was compared with the standard set by the World Health Organization (WHO) for particulate matter less than 2.5 microns thick (PM2.5) of 5 micrograms per cubic metre (µg/m3). PM2.5 can cause severe health problems and early mortality.
Last year’s report considered 2020 as the base year, and found Delhi residents were losing 10.1 years of their lives to severe air pollution. It also considered the revised WHO standards of 5µg/m3 per for PM2.5, as compared to 10µg/m3 earlier.
To be sure, the Covid-19 lockdown was clamped down across India in 2020, shutting down nearly all major activitiess.
After Delhi, the average resident of Gautam Budh Nagar (which comprises Noida and Greater Noida) may lose 11.3 years of their lives, followed by Gurugram (11.2 years), Faridabad (10.8 years) and Ghaziabad (10.7 years), indicating that the entire metropolitan area requires immediate attention in tackling air pollution.
Across India, for which the average life expectancy loss is 5.3 years, the second-most impacted state was Uttar Pradesh (8.8 years), followed by Haryana (8.3 years).
“The most polluted region of India is the northern plains, home to more than a half billion people and 38.9% of the country’s population. In this region, the average resident is on track to lose about 8 years of life expectancy, if the pollution level persists,” the EPIC report said.
“The region contains the capital city of Delhi, the most polluted megacity in the world with annual average particulate pollution of 126.5 micrograms per cubic metre — more than 25 times the WHO guideline,” the report said, finding that average annual particulate pollution increased by 61 between 1998-2021, reducing life expectancy by 3.2 years during the period.
Even if Delhi were to reduce air pollution to national standards, residents would still stand to lose around 8.5 of their lives, with Gautam Budh Nagar and Gurugram residents losing 7.8 years, Faridabad 7.4 years and Ghaziabad residents still losing 7.2 years from average life expectancy. The annual national standard for PM2.5 is 40µg/m3.
EPIC’s life expectancy calculations 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. One of them found that sustained exposure to an additional 10µg/m3 of PM10 reduced life expectancy by 0.64 years. An additional 10 micrograms per cubic metre of PM2.5 reduced life expectancy by 0.98 years.
While particulate matter pollution is largely exacerbated in northern India by geological and meteorological factors, human activity also played a key role in the severe air pollution, the report found.
“This is likely due to the fact that the region’s population density is nearly three times that of the rest of the country, meaning more pollution from vehicular, residential and agricultural sources,” it said. “A denser population also means more human lives are impacted by each pollution source.”
The world’s 50 most polluted districts based on PM2.5 levels are part of the northern plains of India, which was a concern for the country, according to Christa Hasenkopf, director of air quality programmes at EPIC.
“In fact, the top 77 most polluted districts in the world all are in India. It cannot be overstated - there is no greater public health opportunity in the world than to improve the extraordinarily poor air quality currently breathed in by more than half a billion citizens in northern India,” she said in a statement.
Professor SN Tripathi from IIT Kanpur, who is also part of the Steering Committee of the National Clean Air Programme, said the report highlights a well-known problem of severe air pollution not just limited to Delhi-NCR, but to the Indo-Gangetic Plain as a whole.
“This entire region is fertile and has a high population that is densely packed together. There are anthropogenic activities, industries and a rapid rise in vehicles over the years, which, when combined with unfavourable meteorological conditions or local factors like stubble burning, has led to such high pollution. However, the trend over the last few years has been positive and cities and states are working hard to meet the National Clean Air Programme (NCAP) targets, which should be the first goal, followed by the goal of meeting the annual standard of 40 micrograms per cubic metre,” Prof Tripathi said.