Asia at a crossroads: estimates and 25-year trends of the global burden of disease attributable to ambient air pollution

The Lancet has published another systematic analysis from the Global Burden of Disease Study 2015 (GBD 2015), this time exploring spatial and temporal trends in mortality and burden of disease attributable to ambient air pollution from 1990 to 2015 at global, regional and country levels. GBD 2015 estimates the burden of disease attributable to 79 risk factors in 195 countries and identifies air pollution as a leading cause of global disease burden, especially in low-income and middle-income countries.

Exposure to ambient air pollution increases mortality, morbidity and shortens life expectancy. Air pollution is a complex mixture of gases and particles whose sources and composition vary spatially and temporally. The study uses population-weighted annual mean concentrations of particle mass with aerodynamic diameter less than 2.5μm (PM2.5) and tropospheric ozone as indicators for quantifying exposure to air pollution. In 2015, PM2.5 caused an estimated 7.6% of total global mortality and was the fifth-ranking global mortality risk factor.

The findings of the study paint a particularly bleak picture for low- and middle income countries in Asia. Deaths attributable to long-term exposure vary substantially among countries but South and East Asia contributed 59% of the 4.2 million deaths attributable to ambient PM2.5 in 2015. The highest age-standardized rates of death due to PM2.5 exposure can be found in South Asia (133.4 per 100.000 population), Central Asia (85.2 per 100.000 population) and East Asia (83.2 per 100.000 population). Rates in high-income North American, Asian and European countries were four to eight times lower. The Lancet found that ambient PM2.5 ranked among the top ten risk factors for mortality in the world’s ten most populous countries. China and India combined, account for 52% of attributable deaths and 50% of Disability Adjusted Life Years (DALYs) globally. Additionally, Pakistan, India and Bangladesh have the highest age-adjusted mortality rates, more than seven time higher than those of the United States and Japan.

Deaths attributable to ambient particulate matter pollution in 2015

Source: The Lancet

Global mortality due to ambient PM2.5 increased from 1990 to 2015, rising from 3.5 million in 1990 to 3.8 million in 2000, finally reaching 4.2 million in 2015 as a result of increases in pollution and the absolute number of deaths from noncommunicable diseases, especially in China and India, where populations grow and age at the same time. Household air pollution stemming from the burning of solid fuels significantly adds to the problem in low- and middle-income countries.

The authors of the study emphasise the potential for lowering exposure to ambient air pollution and its associated burden of disease. They point towards experiences in the United States, where aggressive air quality management programs focusing on major pollution sources, such as coal combustion and transport, led to increased life expectancy over short timeframes. NCDAPA shares this view and furthermore urges governments at national and subnational level to join the fight against ambient air pollution. Even on the city-level, innovative steps to curb the concentration of PM2.5 and far-sighted urban planning measures can alleviate the burden of air pollution and counter the alarming trends in Asia and worldwide.

by Moritz Laqua: Moritz has been working with NCDAPA since 2015. Before joining, he completed a traineeship in GIZ’s corporate development department, contributing to alliance building and strategic partnership management. At NCDAPA he works on external relations and policy, regularly providing articles and updates on political and legal developments within the field of NCDs. Moritz holds postgraduate degrees in Law and International Relations from the University of Munich and the London School of Economics and Political Science (LSE). He is currently positioned in Southeast Asia.