How Many Years Do We Lose To The Air We Breathe?

Published in
3 min readNov 27, 2018


Calculating Life Years Lost Per Person


The Air Quality Life Index, or AQLI, converts air pollution concentrations into their impact on life expectancy. Produced by the Energy Policy Institute at the University of Chicago (EPIC), the AQLI is based on frontier research by EPIC’s director Michael Greenstone that quantified the causal relationship between human exposure to air pollution and reduced life expectancy. Combining this analysis with highly localized pollution measurements yields unprecedented insight into the true cost of air pollution in communities around the world.

Methodology : Grid-Level Particulates and Population Estimates
The data sources used to construct the AQLI were chosen for their geographic completeness and their methodological consistency between data points across countries. The AQLI incorporates twenty years of annual ambient particulate pollution (PM2.5) concentration estimates. This satellite-derived data, provided by Van Donkelaar et al. (2016), covers the globe at the high resolution of 10km x 10km — in other words, for each year, there is a data point for every area about 1/8 the size of New York City, 1/15 the size of Delhi, or 1/40 the size of urban Beijing.

The AQLI uses population data from the 2015 LandScan Global Population Database, which uses spatial methods to disaggregate census population counts in each country into grid cells of length 30 arc-seconds. These grid cells are about 1 km2 around the Equator, and smaller elsewhere. After combining the detailed population data with the satellite estimates of PM2.5concentrations, the result is a global gridded database of ambient PM2.5 concentrations with associated population counts. The population counts are used as weights when aggregating PM2.5 concentrations and life expectancy results from the grid level up to the local, state, national, and global averages.

The research and results

New Index finds air pollution reduces global life expectancy by nearly 2 years, making it the single greatest threat to human health

Fossil fuel-driven particulate air pollution cuts global average life expectancy by 1.8 years per person, according to a new pollution index and accompanying report produced by the Energy Policy Institute at the University of Chicago (EPIC). The Air Quality Life Index (AQLI) establishes particulate pollution as the single greatest threat to human health globally, with its effect on life expectancy exceeding that of devastating communicable diseases such as tuberculosis and HIV/AIDS, behavioral killers like cigarette smoking, and even war. Critically, the AQLI reports these results in tangible terms that are relatable for most people.

“Around the world today, people are breathing air that represents a serious risk to their health. But the way this risk is communicated is very often opaque and confusing, translating air pollution concentrations into colors, like red, brown, orange, and green. What those colors mean for people’s wellbeing has always been unclear,” says Michael Greenstone, the Milton Friedman Professor in Economics and director of the Energy Policy Institute at the University of Chicago (EPIC).

Seventy-five percent of the global population, or 5.5 billion people, live in areas where particulate pollution exceeds the WHO guideline

“While people can stop smoking and take steps to protect themselves from diseases, there is little they can individually do to protect themselves from the air they breathe,” Greenstone said. “The AQLI tells citizens and policymakers how particulate pollution is affecting them and their communities and reveals the benefits of policies to reduce particulate pollution.”

Source : Michael Greenstone is the Milton Friedman Professor in Economics, the College, and the Harris School, as well as the Director of the Becker Friedman Institute and the interdisciplinary Energy Policy Institute at the University of Chicago.




adyog is an advisory, design, and software development company with a global reach. Learn more: [] []