Despite a growth in vehicle vehicle ownership and vehicle distance travelled between 2010 and 2015, the global fraction of air pollution-related premature deaths by tailpipe emissions stayed nearly the same.
In fact, they dropped slightly, from 11.7 per cent of deaths by all sources of air pollution in 2010 to 11.4 per cent in 2015, even as the global population grew by 5.7 per cent.
Some countries were particularly successful in reducing the impact of transportation on air pollution and, consequently, on health.
From 2010 to 2015, total concentrations of PM.2.5, ozone and black carbon from transportation declined in all regions that implemented world-class standards for fuel quality and new vehicle emissions, including the United States and Canada, EU and the European Free Trade Association countries, and Japan.
The researchers estimate that other regions that have implemented “progressive stages” of emission controls, including Brazil, Argentina, Chile, Russia and Australia have also seen declines in concentrations of these pollutants.
These successes belie an ongoing struggle, however: in absolute numbers, deaths by transport emissions increased– from 361,000 to 385,000, because of a growth in overall deaths by air pollution.
In 2015, that translated to 7.8 million years of life lost and approximately $1 trillion (2015 US$) in health damages globally from PM2.5 and ozone concentrations from tailpipe emissions alone.
“Transportation-attributable health impacts declined in the United States, European Union, and Japan as vehicle emission standards have been implemented, but these reductions have been offset by growing impacts in China, India, and other parts of the world,” said lead author of the study and an associate professor at the George Washington University Milken Institute School of Public Health, Susan Anenberg.
“Unless the pace of transportation emission reductions is accelerated, these health impacts are likely to increase in the future as the population grows, ages, and becomes more urbanized,” she said.
The researchers expect regions with world-class standards to see even further reductions as old vehicle fleets retire, but they encourage decision makers to get the momentum going, as there’s a demonstrated time-lag between putting in place relevant policies, like new vehicle and fuel standards, and realizing their full health benefits— not least because in-use vehicle fleets and related equipment have long lifetimes.