Controlling pollution isn’t entirely in your hands, but the amount of the pollution air you inhale is entirely in your hands – by controlling your walking and cycling speed.
That’s according to researchers at University of British Columbia who have revealed that if you maintain your cycling speed between 12 and 20 kilometres per hour and walking speed between 2 and six kilometres per hour on city roads you will effectively be reducing the amount of polluted air you inhale and still garner the health benefits of cycling and walking.
Researchers say that if you move faster, you will be required to breathe harder to compensate the need for fresh oxygen and because air is polluted in cities, you will be effectively inhaling more polluted air. To find a balance between cycling and walking speed and the amount of polluted air that is inhaled, Alex Bigazzi, a UBC transportation expert in the department of civil engineering and school of community and regional planning, carried out an analysis of U.S. Census-based computer model of 10,000 people.
Bigazzi calculated ideal travel speeds that he calls the minimum-dose speeds (MDS) for different age and sex groups. For female cyclists under 20, the ideal speed linked to the least pollution risk is 12.5 kilometres per hour on average on a flat road. For male cyclists in the same age group, it’s 13.3 kilometres per hour. Ideal travel speeds were at 13 and 15 kilometres per hour for female and male cyclists in the 20-60 age group.
Female and male pedestrians under 20 years old should be walking at speeds around three kilometres per hour, while their older counterparts should look at reaching at least four kilometres per hour, to breathe in the least amount of pollution over a trip. Bigazzi also computed these ideal travel speeds for other road grades.
The findings, which build on Bigazzi’s recent research on the high amounts of toxic chemicals absorbed by cyclists on busy city streets, are described in a paper published recently in the International Journal of Sustainable Transportation.