Pollution means city walkers and cyclists should watch their speed

Huffington Post featured an interview with Alex Bigazzi, a UBC civil engineering professor, who found exerting too much energy while walking or biking on city streets can increase the amount of airborne pollutants you inhale.

He explained what he calls minimum dose speed (MDS), or the optimal speed which leads to the least total pollution inhalation dose over a trip.

“Across a wide range of people, the MDS is three to six kilometres per hour walking and 12 to 20 kilometres per hour bicycling on level ground. The MDS is lower when going up hills. For the vast majority of people, the MDS corresponds to a moderate exercise intensity on relatively flat terrain,” he said.