Air pollution reducing life expectancy in India by 5 years: Study

Air pollution is the greatest threat to human health in India reducing life expectancy by five years with Delhi, the most polluted state, standing to gain it by 10 years on average if annual average pollution levels did not exceed five micrograms per cubic metres, according to Energy Policy Institute at the University of Chicago (EPIC)'s Air Quality Life Index (AQLI) released on Tuesday. In contrast, child and maternal malnutrition reduces average life expectancy by about 1.8 years and smoking by 1.5 years, it said.

Delhi was also the most polluted state with around 9.7 years of life expectancy lost on average as per AQLI's analysis last year based on the old revised World Health Organisation (WHO) target of 10 micrograms per cubic metre for reducing the burden of disease. As per this year's analysis, Uttar Pradesh, Bihar, Haryana and Tripura are among the top five polluted states, which stand to gain the most in life expectancy if the pollution levels are met.

Globally, India is the second most polluted country preceded by Bangladesh, where life expectancy reduced by 6.9 years in 2020 due to poor air and followed by Nepal (4.1 years), Pakistan (3.8 years) and the Democratic Republic of Congo (2.9 years).

The AQLI found that particulate air pollution takes 2.2 years off global average life expectancy, or a combined 17 billion life years. The impact on life expectancy is comparable to that of smoking, more than three times that of alcohol use and unsafe water, six times that of HIV/AIDS, and 89 times that of conflict and terrorism, the analysis said.

"It would be a global emergency if Martians came to Earth and sprayed a substance that caused the average person on the planet to lose more than two years of life expectancy. This is similar to the situation that prevails in many parts of the world, except we are spraying the substance, not some invaders from outer space," said Milton Friedman Distinguished Service Professor in Economics Michael Greenstone, the AQLI's creator along with his colleagues at the EPIC. "Fortunately, history teaches us that it does not need to be this way. In many places around the planet, like the United States, strong policies, supported by an equally strong willingness for change, have succeeded in reducing air pollution."

All of India's 1.3 billion people live in areas, where the annual average particulate pollution level exceeds the WHO limit. Over 63% of the population lives in areas that exceed the country's own national annual air quality standard of 40 micrograms per cubic metre, the analysis found.

Since 1998, average annual particulate pollution has increased by 61.4%, leading to a further reduction in average life expectancy of 2.1 years. About 44% of the world's increase in pollution has come from India since 2013.

In the Indo-Gangetic plains, 510 million residents, nearly 40% of India's population, are on track to lose 7.6 years of life expectancy on average, if current pollution levels persist. Residents of Lucknow stand to lose 9.5 years of life expectancy if pollution levels persist.

AQLI translates particulate air pollution into its impact on life expectancy. It quantifies the causal relationship between long-term human exposure to air pollution and life expectancy.

For its fresh analysis, the AQLI team used air pollution data from 2020 when Covid-19-related restrictions were imposed globally. "According to new and revised satellite-derived PM2.5 data, the global population weighted-average PM2.5 level declined slightly between 2019 and 2020, from 27.7 to 27.5 micrograms per cubic metres — more than five times the WHO's revised guideline of 5 micrograms per cubic metres—despite a rapid slowdown in economic activities across the globe. In fact, global particulate pollution concentrations today are roughly the same as they were in 2003," the analysis said.

Since 1998, average annual particulate pollution has increased by 61.4%, leading to a further reduction in average life expectancy of 2.1 years. About 44% of the world's increase in pollution has come from India since 2013.

In the Indo-Gangetic plains, 510 million residents, nearly 40% of India's population, are on track to lose 7.6 years of life expectancy on average, if current pollution levels persist. Residents of Lucknow stand to lose 9.5 years of life expectancy if pollution levels persist.

AQLI translates particulate air pollution into its impact on life expectancy. It quantifies the causal relationship between long-term human exposure to air pollution and life expectancy.

For its fresh analysis, the AQLI team used air pollution data from 2020 when Covid-19-related restrictions were imposed globally. "According to new and revised satellite-derived PM2.5 data, the global population weighted-average PM2.5 level declined slightly between 2019 and 2020, from 27.7 to 27.5 micrograms per cubic metres — more than five times the WHO's revised guideline of 5 micrograms per cubic metres—despite a rapid slowdown in economic activities across the globe. In fact, global particulate pollution concentrations today are roughly the same as they were in 2003," the analysis said.

AQLI Director Christa Hasenkopf said this shows that air pollution is a very stubborn problem which requires consistent and strong action.

South Asia bears the highest burden of air pollution. India, Pakistan, Bangladesh, and Nepal remain among the top five most polluted countries in the world. South Asia accounts for more than half, 52%, of the expected lost life years globally due to high pollution. In each of these countries, the impact of air pollution on life expectancy is substantially higher than that of other large health threats.

The average resident of the four countries is exposed to particulate pollution levels that are 47% higher than at the turn of the century. If pollution levels in 2000 remained constant over time, the residents in these countries would be on track to lose 3.3 years of life expectancy.

India globally faces the highest health burden of air pollution due to its high particulate pollution concentrations and large population. The particulate pollution levels have increased from 53 micrograms per cubic metre in 2013 to 56 micrograms per cubic metre today—roughly 11 times higher than the WHO limit.

China stands to lose 2.5 years of life expectancy but it has also gained two years due to the reduction in pollution levels since 2013. China's pollution has been decreasing since the country began a "war against pollution" in 2014. This decline continued through 2020, with pollution levels down 39.6% compared to 2013, the analysis said. Due to these improvements, the average Chinese citizen can expect to live two years longer, provided the reductions are sustained. Beijing recorded the largest decline in air pollution between 2013 and 2020, with PM2.5 levels falling from 85 to 38 micrograms per cubic metre in just seven years—a 55% decline. From 2019 to 2020, Beijing's pollution fell by 8.7.