Statistics from the World Health Organization (WHO) show that air pollution kills an estimated seven million people throughout the globe every year and nine out of ten people are exposed to high levels of pollutants. A new study has shown that people who drive and ride in cars from the world’s least affluent cities are exposed to a disproportionate amount of in-car air pollution due to the fact that they rely heavily on opening their windows for ventilation.
A global team of researchers led by Surrey’s Global Centre for Clean Air Research(GCARE) investigated levels for commuters in ten different global cities in the following countries – India, Bangladesh, Brazil, Egypt, Columbia, Iraq, Tanzania, China, Malawi, and Ethiopia.
The team examined levels of two air pollution components – PM2.5 (fine particles that are 2.5 microns or smaller) and PM10 (fine particles that are 10 microns of less). PM2.5 is more harmful since the particles are smaller and have a higher probability of going deeper into the lungs and causing harm.
They investigated exposure levels inside vehicles during peak driving hours in the morning and evening in addition to off-peak hours in the middle of the day. They also measured how levels of exposure changed when drivers used re-circulation systems, fans or simply opened the windows of the car.
They discovered that drivers in some of the world’s poorest cities had higher levels of in-car pollution. Irrespective of the model of the car and the city, a windows-open setting indicated the highest exposure followed by fan-on and re-circulation. Exposure to pollution for windows-open during off-peak hours was 91% and 40% less than the morning and evening peak hours, respectively. The team also found that the windows-open setting exposed passengers to hotspots of air pollution for up to a third of the total length of travel.
The study showed that commuters who turn on the re-circulation are exposed to about 80% less harmful particles than those who open the windows of their car. Car cabin filters were more effective in removing pollution than fine particles which suggests that if new cars had more efficient filters it could lower the overall exposure of car commuters.
The team reports that we need as many cars as possible off roads or more green vehicles to reduce exposure to air pollution. However, this is a distant dream in many ODA (Official Development Assistance) countries. Cars that are air conditioned are unattainable for many vulnerable and poor commuters across the globe. The data is clear and coherent for all of the ten participating cities.
The team believes that they must now work with global partners to insure they have the information needed to put in place policies, programs and strategies to protect the most vulnerable in their communities and find realistic solutions to these serious problems.
The study has shown important conclusions that can help commuters make decisions throughout their day to day lives to protect their health. Even simple choices such as traveling during off-peak hours can go quite far in reducing their exposure to air pollution.
Through working with GCARE and global collaborators on the study, the team was given access to affordable technology to be able to collect novel data sets that had not been available for cities in the parts of the world they studied. They also got to see where the cities stood in comparison to other global cities in developing countries. This gave them the capability to share much needed knowledge and best practices.
To view the original scientific study click below
In-car particulate matter exposure across ten global cities.
