Pollution levels inside of cars are higher for motorists that drive with their windows down, according to a World Health Organisation (WHO) study. The research suggests that those who keep their windows down are exposed to 80% more air pollution.
The research team investigated PM2.5 and PM10 exposure levels inside vehicles in 10 cities in ODA countries during peak hours in the morning and evening, as well as off-peak hours in the middle of the day. The scientists measured how exposure levels changed when drivers used recirculation systems, fans and simply opened the windows.
Irrespective of the city and car model used, a windows-open setting showed the highest exposure, followed by fan-on and recirculation. Pollution exposure for windows-open during off-peak hours was 91% percent and 40% less than morning and evening peak hours, respectively. The study also found that the windows-open setting exposed car passengers to hotspots of air pollution for up to a third of the total travel length.
The study found that commuters who turn on the recirculation are exposed to around 80% less harmful particles than those who open their car windows. Car cabin filters were more effective in removing pollution than fine particles, suggesting that if new cars had more efficient filters, it could reduce the overall exposure of car commuters.
Air pollution kills an estimated seven million people worldwide every year and nine out of 10 people breathe air with high levels of pollutants. It was discovered that drivers in some of the world’s poorest cities experienced higher levels of in-car pollution.
Professor Prashant Kumar, director of Global Centre for Clean Air Research (GCARE) at the University of Surrey, said, “To be blunt, we need as many cars as possible off the road, or more green vehicles to reduce air pollution exposure. This is yet a distant dream in many ODA countries. Air-conditioned cars are unattainable for many poor and vulnerable commuters across the world, but our data is clear and coherent for all 10 participating cities.
“We must now work with our global partners to make sure they have the information needed to put in place programs, policies and strategies to protect the most vulnerable in our communities and find realistic solutions to these serious problems.”
Professor Abdus Salam from the University of Dhaka said, “The study has drawn important conclusions that can help commuters make decisions in their day-to-day lives to protect their health. Simple choices, like traveling during off-peak hours, can go a long way in reducing their exposure to air pollution.”
The study, published by the Science of the Total Environment journal, a global team of researchers led by Surrey’s Global Centre for Clean Air Research (GCARE) investigated air pollution exposure levels for commuters in 10 different global cities – Dhaka (Bangladesh), Chennai (India), Guangzhou (China), Medellín (Colombia), São Paulo (Brazil), Cairo (Egypt), Sulaymaniyah (Iraq), Addis Ababa (Ethiopia), Blantyre (Malawi), and Dar-es-Salaam (Tanzania).
The study was part of the Clean Air Engineering for Cities (CArE-Cities) project, a seed funding project awarded by the University of Surrey under Research England’s Global Challenge Research Funds. CArE-Cities involves 11 Development Assistance Committee-listed (DAC) 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.