Commuters make their way amid smoggy conditions in New Delhi [File: Prakash Singh/AFP]

New Delhi, June 14 (RHC)-- Microscopic air pollution caused mostly by burning fossil fuels is reducing life expectancy by nearly 10 years in the Indian capital, one of the most polluted cities in the world, according to a new study.

The study by Energy Policy Institute at the University of Chicago (EPIC), released on Tuesday, said lung and heart disease caused by so-called PM2.5 pollution reduces life expectancy in the Indian states of Uttar Pradesh and Bihar – home to 300 million people – by eight years.

Across South Asia, an average person would live five years longer if levels of fine particulate matter met World Health Organization standards, according to the Air Quality Life Index published by EPIC.  Worldwide, air pollution is shortening lives by more than two years, it said.

PM2.5 pollution – 2.5 microns across or less, roughly the diameter of a human hair – penetrates deep into the lungs and enters the bloodstream. In 2013, the United Nations classified it as a cancer-causing agent.

The WHO says PM2.5 density in the air should not top 15 microgrammes per cubic metre in any 24-hour period, or 5mcg/m3 averaged across an entire year.

Faced with mounting evidence of damaging health effects, the WHO tightened these standards last year, the first change since establishing air quality guidance in 2005.

“Clean air pays back in additional years of life for people across the world,” lead research Crista Hasenkopf and colleagues said in the Air Quality Life Index report.  “Permanently reducing global air pollution to meet the WHO’s guidelines would add 2.2 years onto average life expectancy.”

Almost all populated regions in the world exceed the WHO guidelines, more so in Asia: by 15-fold in Bangladesh, 10-fold in India, and nine-fold in Nepal and Pakistan, said the report.

Surprisingly, PM2.5 pollution in 2020, the most recent data available, was virtually unchanged from the year before despite a sharp slowdown in the global economy and a corresponding drop in carbon dioxide (CO2) emissions due to COVID-19 lockdowns.

“In South Asia, pollution actually rose during the first year of the pande
mic,” the authors noted.