Air Pollution Linked to Over 7% of Daily Deaths in Major Indian Cities: Study

On average, 7.2 percent of daily deaths in ten of India’s largest and most polluted cities, including Delhi, Bengaluru, and Mumbai, are associated with PM2.5 levels exceeding World Health Organization (WHO) safe exposure guidelines, according to a study published in The Lancet Planetary Health journal.

Delhi exhibited the highest proportion of both daily and annual deaths attributable to PM2.5 air pollution, caused by particulate matter 2.5 micrometers or smaller in diameter. Major sources of this pollution include vehicular and industrial emissions. Researchers found that daily exposure to PM2.5 pollution in Indian cities is linked to an increased risk of death, with locally generated pollution likely contributing to these fatalities.

The international research team included experts from Banaras Hindu University in Varanasi and the Centre for Chronic Disease Control in New Delhi. They discovered that an increase of 10 micrograms per cubic meter in the two-day average of PM2.5 pollution (short-term exposure) was associated with a 1.4 percent rise in daily mortality. When focusing on pollution levels below Indian air quality standards, the risk doubled to 2.7 percent per 10 microgram per cubic meter increase.

Indian air quality standards allow up to 60 micrograms per cubic meter of PM2.5 over a 24-hour period, compared to WHO’s stricter guideline of 15 micrograms per cubic meter. The study found a 0.31 percent increase in daily mortality per 10 micrograms per cubic meter rise in PM2.5 in Delhi, while Bengaluru saw a 3.06 percent increase.

The study highlighted stronger links between daily exposure to PM2.5 pollution and locally generated pollutants, suggesting that local pollution might be causing these excess deaths. The causal effects were particularly strong in cities with lower air pollution concentrations, such as Bengaluru, Chennai, and Shimla.

Titled “the first multi-city, time series analysis of short-term exposure to PM2.5 and daily mortality in India,” the study analyzed approximately 3.6 million daily deaths across ten Indian cities from 2008 to 2019. The other cities included in the analysis were Ahmedabad, Hyderabad, Kolkata, Pune, Shimla, and Varanasi.