In its latest pollution report using data from the World Health Organization (WHO), the Guardian identified cities across the globe where pollution levels are particularly dire. So dire, that after just 30 minutes of outdoor cycling or walking the benefits of cardio are negated by the detrimental effects of contaminated air.
The cities with the biggest issue are: Kaduna (Nigeria), Bamenda (Cameroon), Yunbu (Saudi Arabia), Kampala (Uganda), Tetovo (FYR Macedonia), Baghdad (Iraq), Doha (Qatar), Zabol (Iran), Gwalior (India), Alwar (India), Allahabad (India), Chittagong (Bangladesh), Beijing (China), Wuhan (China).
Researchers calculated the amount of time when the health payoff of exercise was outweighed by the danger of pollution, the “breakeven point,” and currently western commuters have nothing to fear.
“The benefits of active travel outweighed the harm from air pollution in all but the most extreme air pollution concentrations,” Audrey de Nazelle, one of the authors of the report, told the Guardian. “It is not currently an issue for healthy adults in Europe in general.”
That being said, last month London’s pollution levels exceeded those of Beijing — a city with a breakeven point of under an hour. The health hazards of pollution can be severe, so try to avoid cycling along the busiest junctions, no matter where you live.