Some of the world’s cities suffer disproportionate economic losses because of the health consequences of in-car air pollution, according to a new study by an international team led by researchers at the University of Surrey (UK).

Surrey’s Global Centre for Clean Air Research (GCARE) set out to investigate whether the amount of PM_2.5 drivers inhaled is connected to the duration drivers spend in pollution hotspots and socio-economic indicators such as gross domestic product (GDP). For the study, published in the journal Environment International, the team monitored pollution hotspots in 10 global cities: Dhaka (Bangladesh); São Paulo (Brazil); Guangzhou (China); Medellín (Colombia); Cairo (Egypt); Addis Ababa (Ethiopia); Chennai (India); Sulaymaniyah (Iraq); Blantyre (Malawi); and Dar-es-Salaam (Tanzania). 

Across all the cities in the study, researchers found that drivers only needed to spend a short amount of time in high-pollution hotspots to inhale a significant amount of PM_2.5 particles. For example, drivers in Guangzhou and Addis Ababa spent 26 and 28% of their commute in hotspot areas, which contributed to 54 and 56% of the total amount of air pollution inhaled on their trip.

The researchers found that the cities where drivers were exposed to the highest levels of PM_2.5 pollution—Dar-es-Salaam, Blantyre and Dhaka—also experienced higher death rates per 100,000 commuting car population per year. The low PM_2.5 levels in Medellín, São Paulo and Sulaymaniyah corresponded with very low death rates.

The international study assessed economic losses by measuring a city’s death rate caused by PM_2.5 in-car exposure against its GDP per capita. It found that, for most cities, lower GDP linked directly to more significant economic losses caused by in-car PM_2.5 exposure—with Cairo and Dar-es-Salaam being impacted the most (losses of 8.9 and 10.2 million US dollars per year, respectively).

The team also found that, except for Guangzhou, cities with higher GDP per capita have less hotspot areas during an average route trip, thus decreasing the risk to drivers.

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. 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.

—Professor Prashant Kumar, Principal Investigator of CArE-Cities Project, Associate Dean (International) and Founding Director of GCARE at the University of Surrey

The study was part of the Clean Air Engineering for Cities (CArE-Cities) project and builds upon its previous work around car exposure. CArE-Cities is a seed funding project awarded by the University of Surrey under the Research England’s Global Challenge Research Funds. CArE-Cities involves 11 Development Assistance Committee (DAC) listed countries and aspires to bring cleaner air to cities by building a knowledge exchange platform. Its activities include joint workshops, researchers exchange and pilot studies to address urban development and health impact assessment agendas in ODA countries.

Resources

• Kumar, P., Hama, S., Abbass, R. A., Nogueira, T., Brand, V. S., Abhijith, K. V., de Fatima Andrade, M., Asfaw, A., Aziz, K. H., Cao, S. J., El-Gendy, A., Khare, M., Muula, A. S., Nagendra, S. M. S., Ngowi, A. V., Omer, K., Olaya, Y., Salam, A. (2021) “Potential health risks due to in-car aerosol exposure across ten global cities.” Environment International 155, 106688 doi: 1​0​.​1​0​1​6​/​j​.​e​n​v​i​n​t​.​2​0​2​1​.​1​0​6​6​8​8