In many city centers cycling is on the rise. In 2018, members of the popular bike app Strava in the US uploaded over 11 million bike commutes, up 30.8% from 2017. Cities have invested in bike lanes because cycling has social benefits (and driving has social costs). Cyclists combine exercise and commuting. Electric bikes also enable people to use their bike for trips they previously thought were too uphill or too long. But is cycling in the middle of diesel fumes and road dust good for you?
Unsurprisingly, research shows that areas used for cycling leisure trips are less exposed to air pollution than areas used for commuter trips. After all, when you finally have time for a cycling trip during the weekend, why on earth would you target the heavily congested road in the city center that you have to use the rest of the week? However, that means those biking to work are much more likely to be exposed to high levels of air pollution than those biking on their free time – all the more so since they’re likely to repeat those trips alongside polluting buses and cars much more often than those cycling for leisure.
Drop that surgical mask
OK, so commuters have a problem. what can they do about it? If you use a cotton surgical mask or buff against air pollution, you may as well stop bothering. Those will not at all stop the particles that are likely to hurt your lungs the most, as their size is perhaps 1/400th of a millimeter. Research suggests even more advanced masks (so-called N95 and N99 masks that are supposed to remove 95-99% of particles) work much better in the lab than when people actually wear them.
The more you move your head and face, the lower the chance that the mask prevents unfiltered air from seeping in around the edges. And cyclists do tend to move. Efficiency is reduced further if you have facial hair (ignore this advice if you are a woman, or a middle-aged man in lycra; in the latter case you presumably already abide by Velominati Rule #50).
Some anti-pollution masks likely do reduce your exposure so much that you might choose to ignore that they make you look like a prominent Star Wars figure actively engaged in biological warfare. The best ones even come with an exhale valve that reduces condensation. Useful comparisons can be found here and here.
Sell bike and buy bus card? Don’t.
Does all this tempt you to stop commuter cycling? Don’t. Researchers conclude that health benefits outweigh the air pollution risks – if you’re not commuting to one of the Chinese and Indian cities with the most extreme pollution levels (above 100 µg/m³), that is. Instead of heading towards the sofa and selling your bike, try avoiding the streets and roads you think are most polluted.
In theory, cyclists could also reduce speed to reduce the impact of air pollution. That way we would breathe in at a slower pace, and need to take less deep breaths, hence our lungs will be exposed to fewer liters of polluted air. Everyone remotely familiar with cycling – even commuter cycling – knows slowing down is just a theoretical possibility, and will remain so.