An international team of air pollution experts, led by the University of Surrey, monitored pollution hotspots in 10 global cities, namely São Paulo (Brazil); Dhaka (Bangladesh); Cairo (Egypt); Medellín (Colombia); Guangzhou (China); Addis Ababa (Ethiopia); Sulaymaniyah (Iraq); Chennai (India); Dar-es-Salaam (Tanzania); and Blantyre (Malawi). The study was published in the Environment International journal.
The Global Centre for Clean Air Research (GCARE) of the University of Surrey set out to find out whether the amount of fine air pollution particles (PM2.5) inhaled by drivers is linked to the time they spend in pollution hotspots and socio-economic indicators, like gross domestic product (GDP).
Across all the cities considered in the study, the researchers observed that even when drivers spent only a brief amount of time in the high pollution hotspots, they still inhaled a considerable amount of PM2.5 particles. For instance, drivers in Addis Ababa and Guangzhou spent 28% and 26% of their commute in hotspot areas and this contributed to 56% and 54% of the total amount of air pollution inhaled on their trip.
The team also noted that in cities where the drivers were exposed to maximum levels of PM2.5 pollution — for example, Blantyre, Dhaka, and Dar-es-Salaam — there were higher death rates per 100,000 commuting car population every year. The low PM2.5 levels in Sulaymaniyah, São Paulo and Medellín corresponded with very low death rates.
The researchers also evaluated the economic losses by quantifying a city’s death rate induced by PM2.5 car exposure against its GDP per capita. They found that lower GDP was directly associated with more economic losses caused by in-car PM2.5 exposure in a majority of cities. Dar-es-Salaam and Cairo were impacted the most with a loss of 10.2 and 8.9 million US dollars per year, respectively.
Except for Guangzhou, cities with higher GDP per capita have fewer hotspot areas during an average route trip and thus reduce the risk to drivers, noted the researchers.
Our global collaborative project has confirmed that air pollution disproportionately affects developing countries. Many countries are caught in a vicious cycle where their low GDP leads to higher pollution exposure rate for drivers, which leads to poorer health outcomes, which further damages the economy of those cities.
Prashant Kumar, Professor and Associate Dean (International) and Founding Director, GCARE, University of Surrey
Professor Kumar, who is also the Principal Investigator of the CArE-Cities Project, added, “This is discouraging news — but it should galvanise the international community to find and deploy measures that mitigate the health risks faced by the world's most vulnerable drivers.”
If we are ever to make a world where clean air is available to all, it will take a truly global collaborative effort—such as CArE-Cities. We hope to continue to work closely with Surrey and other global partners, sharing knowledge and expertise that will make a cleaner future a reality.
Shi-Jie Cao, Professor and a collaborative partner, Southeast University
“If developing countries are to not be left behind in the struggle against air pollution and climate change, it is important that we build the capacity and knowledge to gather on-the-ground data. This project is a small but a significant step in the right direction for Malawians; a direction which will lead to better decisions and cleaner air for Malawi, ” concluded Adamson Muula, Professor and a collaborative partner, formerly from the University of Malawi and now Head of Public Health, Kamuzu University of Health Sciences (KUHeS).
Kumar, P., et al. (2021) Potential health risks due to in-car aerosol exposure across ten global cities. Environment International. doi.org/10.1016/j.envint.2021.106688.