ONE IN every eight deaths in India last year could be attributed to air pollution, which now contributes to more disease burden than smoking, according to a study published in The Lancet Planetary Health journal. The states which recorded the highest exposure to particulate matter PM 2.5 were Delhi, Haryana and Punjab.
According to the study by the India State-Level Disease Burden Initiative, which offers the first comprehensive estimates of deaths, disease burden, and life expectancy reduction associated with air pollution in each state, 12.4 lakh deaths in India in 2017 were attributable to air pollution — 6.7 lakh due to outdoor particulate matter and 4.8 lakh due to household air pollution. Of these, over half were aged less than 70 years.
“The average life expectancy in India would have been 1.7 years higher if the air pollution levels were less than the minimal level causing health loss, with the highest increases in the northern states of Rajasthan (2.5 years), Uttar Pradesh (2.2 years), and Haryana (2.1 years),” said the study.
The estimates show that India, which accounts for 18 per cent of the global population, recorded a 26 per cent of the global premature deaths and disease burden due to air pollution.
“India has one of the highest annual average ambient particulate matter PM 2.5 exposure levels in the world. In 2017, no state in India had an annual population weighted ambient particulate matter mean PM 2.5 less than the WHO recommended level of 10 µg/m³, and 77 per cent of India’s population was exposed to mean PM 2.5 more than 40 µg/m³, which is the recommended limit set by the National Ambient Air Quality Standards of India,” it said.
PM 2.5 particles are those that are suspended in air and have a diameter lesser than 2.5 microns. While Delhi, Haryana and Punjab recorded the highest exposure to ambient particulate matter, Bihar, Uttar Pradesh, Rajasthan and Jharkhand recorded the highest levels of both ambient particulate matter and household air pollution.
However, high pollution levels do not necessarily translate into a high disease burden. Delhi, for example, has high ambient air pollution level but the number of deaths are comparatively lower.
Uttar Pradesh recorded the highest number of deaths attributable to air pollution (2.60 lakh), followed by Maharashtra (1.08 lakh) and Bihar (96,967).
Explaining the methodology of the study, senior author Dr Lalit Dandona, Distinguished Research Professor, PHFI, and Director, India State-Level Disease Burden Initiative, said: “Deaths caused by diseases linked to air pollution in each state of India were calculated based on the level of air pollution in those states. We used evidence from many studies from across the world, including India, to estimate the contribution of air pollution to deaths.”
The study noted that contrary to the popular association of air pollution with respiratory diseases only, in India, the disease burden included ischaemic heart disease, stroke, chronic obstructive pulmonary disease and lung cancer, which is commonly associated with smoking.
“The findings in this paper, that one out of every eight deaths in India can be attributed to air pollution, and that air pollution is now responsible for more disease burden in India than tobacco use, would help increase the momentum further for control of air pollution. With substantial variations between the states, the estimates of outdoor and household air pollution exposure for every state, and the state-specific number of deaths and life-expectancy reduction associated with air pollution would be useful to guide policy suitable for the situation in each state,” said Dr Dandona.
According to the WHO database of air pollution, 14 of the 15 cities with the worst air pollution in the world are in India. The study said the experience in controlling air pollution in Mexico City and Beijing could be “instructive” for dealing with the extremely high pollution levels in New Delhi and other cities of India.
The India State-Level Disease Burden Initiative is a joint initiative of the Indian Council of Medical Research (ICMR), Public Health Foundation of India (PHFI), and Institute for Health Metrics and Evaluation (IHME) in collaboration with the Ministry of Health and Family Welfare, along with experts and stakeholders associated with over 100 Indian institutions.
Releasing the report, Dr Balram Bhargava, Secretary, Health Research, said: “It is important to have robust estimates of the health impact of air pollution in every state of India in order to have a reference for improving the situation. Household air pollution is reducing in India, facilitated by the Pradhan Mantri Ujjwala Yojana. There is increasing political momentum in India to address air pollution. The findings reported today systematically document the variations among states, which would serve as a useful guide for making further progress in reducing the adverse impact of air pollution in the country.”
Responding to a question on whether air purifiers and masks are effective, Dr Bhargava said that while they do reduce inhalation of PM 2.5, “nothing is 100 per cent in biological systems”.