A recent study conducted by Indian institute of tropical meteorology (IITM), Pune shows that exposure to fine particulate matter in India reduces human life expectancy by about 3.4 ± 1.1 years. Delhi tops the list in the number of years lost to almost 6.3 ± 2.2 years due to exposure to particulate matter (PM) 2.5.

The study, titled 'Premature Mortalities due to PM 2.5 and Ozone Exposure in India', conducted in collaboration with the National Centre for Atmospheric Research (NCAR), Colorado, quantifies, present-day premature mortalities associated with the exposure to near-surface PM 2.5 and ozone concentrations in India using a regional chemistry model. 
 
The study which is based on data compiled in the 2011 census, reports the following:

•    In 2011, about 5,70,000 premature deaths in India were caused by exposure to PM 2.5 and an additional 12,000 were caused by exposure to ozone.

•    The Indo-Gangetic region accounts for a large part (42%) of the estimated premature mortalities. This includes Uttar Pradesh and Maharashtra. While UP recorded 15% of the country's deaths due to pollution, Maharashtra stood second with 10%. This is followed by West Bengal (9%) and Bihar (8%).

•    Andhra Pradesh, Tamil Nadu, Gujarat, Karnataka, Madhya Pradesh, Orissa and Rajasthan collectively account for 32% of the countrywide premature mortalities.

•    Mortalities due to exposure to harmful ozone pollution is 18% in UP which tops the list of total deaths. Bihar is (11%); West Bengal (9.5%) and Maharashtra (7%) come after that.
 
•    The economic cost of the estimated premature mortalities associated with PM 2.5 and ozone exposure together is about 640 billion USD in 2011, which is a factor of 10 higher than total expenditure on health by public and private expenditure.
 
ITM scientist Sachin Ghude, who was involved in the study, was quoted by The Times of India saying, "Although these results are in line with other global estimates, such as the World Health Organization (WHO) and the Global Burden of Diseases (GBD), there's no physical way to tell who has actually been killed by air pollution."

Ghude added, "The methods used in this study rely on statistical algorithms to construct estimates about a population's response to pollution exposure using previous concrete observations on pollution and public health.