Air pollution has reduced average life expectancy around the world by 1.67 years, according to the Health Effects Institute (HEI) who have released their annual State of Global Air report.
The report includes the latest worldwide results on air pollution exposure and its health burden based on the 2017 GBD (Global Burden of Disease) study, which has been tracking causes of deaths since 1990.
It ranked air pollution fifth among all mortality risk factors globally, accounting for nearly 5 million early deaths and 147 million years of healthy life lost.
Ambient PM2.5 accounted for 2.9 million deaths, while household air pollution accounted for 1.6 million deaths.
It also found that in 2017, 92% of the world’s population still lived in areas where PM2.5 exceeds the World Health Organisation’s (WHO) guideline for healthy air.
Other findings in the study were:
- Nearly half of the world’s population, a total of 3.6 billion people, were exposed to household air pollution in 2017.
- In 2017, exposure to PM2.5 was the third leading risk factor for type 2 diabetes deaths, after high blood sugar and high body mass index.
- Since 1990, the percentage of people living in areas that fail to meet even the least-stringent PM2.5 target of IT-1 (35 µg/m3), has remained steady at around 54%.
Life expectancy in developing countries was greatly reduced as often ambient air pollution is high and cooking with solid fuels is common.
In South Asia, life expectancy loss from air pollution is 2 years and 6 months whereas in sub-Saharan Africa, where more than 80% of people cook with solid fuels, life expectancy is cut by almost 2 years.
Scientists used PM2.5 data from monitoring stations around the world but in developing countries where the technology was unavailable, researchers combined available ground measurements with observations from satellites and information from global chemical transport models.
They then estimated annual average concentrations of PM2.5 across the entire globe divided into blocks or grid cells.
To estimate the annual average PM2.5 exposures for the population in a specific country, scientists combined the concentrations in each block with the number of people living within each block to produce a population-weighted annual average concentration.
The report concludes: ‘The growing burden of disease from air pollution is among the major challenges facing national governments and public health officials, with far-reaching implications for national economies and human well-being.
‘Better understanding the sources of air pollution and key contributors to its health burden is a critical next step for implementing effective air pollution control policies.
‘In each country, it is important to parse the critical interplay among trends in air pollution levels, population structure, underlying disease, and economic factors that contribute to the estimates of health burden and loss of life expectancy.’