A New Strategy for Reducing Air Pollution Exposure on Your Bike?
If you ride in downtown San Francisco with any regularity, you know what it feels like to get a face full of exhaust. When you ride your bike in the city, you’re doing great things for your health — getting aerobic exercise, building muscle, and increasing your lung capacity — but you’re also sometimes breathing in some things that can make you feel downright sick.
Most cyclists have accepted that there’s only so much you can do to avoid air pollution. You can choose less high-traffic routes, so there are fewer cars and buses around to blow exhaust in your face, but that’s about it.
And in truth, the health benefits of cycling definitely outweigh the risks of being exposed to pollution. But it never hurts to find room for improvement, right?
That’s what one scientist in British Columbia, Canada thinks.
How fast or slow to go to avoid excess air pollution?
According to Bicycling.com:
“Alex Bigazzi, a University of British Columbia transportation expert who commutes by bike, is exploring the idea that there are optimal speeds at which cyclists and pedestrians looking to minimize pollution exposure should travel.
His findings so far were recently published in the International Journal of Sustainable Transportation, and per his results, he argues that riding within specific speed ranges allows us to stay healthier in traffic.”
So what is the ideal speed for staying out of the way of exhaust and air pollution?
Bigazzi created a computer model that included data for 10,000 different kinds of cyclists — people of all ages, genders, and body mass indices — and found what he called the “minimum-dose speed” that allowed all of those cyclists to ride at a healthy, brisk speed while minimizing their exposure to air pollution.
“The faster you move, the harder you breathe and the more pollution you could potentially inhale, but you also are exposed to traffic for a shorter period of time,” says Bigazzi. “We’re trying to look at minimizing the total volume of air inhaled over a fixed travel distance.”
In other words, the amount of pollution in the air doesn’t change. But the amount of it that you inhale does change, depending on how far and fast you are going and therefore, how long you are breathing in pollution air and how much extra air you are taking in during that time.
Bicycling.com reports on his findings for the optimal speed to reduce your air pollution intake while riding your bike in the city:
“The total MDS range for cyclists ended up being 12 to 20 kilometers per hour (7.45 to 12.43 miles per hour) when riding over flat ground. Because we work harder riding uphill and take in more air, our MDS adjusts. Bigazzi found that for grades up to five percent, bicycle MDS declines by 1.4 to 1.6kph) per one percent grade.
For example, for female cyclists under 20, MDS is 12.5kph on average, on a flat road. For male cyclists in the same age group, it’s 13.3kph.”
Is this possible to use in practice?
This study is only the first step for finding ways to reduce the amount of air pollution that cyclists take in every day. And unfortunately, it doesn’t offer a perfect diagnosis or action plan that every cyclist can use today.
Since it is based on models, it doesn’t offer a perfect MDS for every individual rider. Everyone has a slightly different age, weight, fitness level, riding environment, etc — there are simply too many factors to allow for you to make a perfect plan for balancing your speed and air pollution intake. Plus, it’s not always possible to ride at a designated speed for your entire route anyways.
However, this study does offer some useful ideas for the everyday cyclist.
The first tip — whenever possible — is to simply avoid high-traffic roads. The best way to reduce your exposure to air pollution is to put yourself in a place where it isn’t as great a factor. If there aren’t lots of side street options, try looking for creative solutions like parks, where you can ride in a completely car-free environment.
If you must ride on a busy road, the next tip is to ride at a steady rate that isn’t so fast that you’re breathing very deeply. You want to maintain a fairly regular, low intake of oxygen; breathing hard from cycling too fast will only cause you to take in more pollution. But don’t ride too slow, either; try to find a balance of moving with purpose, but not overexerting yourself.
Air pollution is hardly the biggest or most immediate risk factor for cyclists on a busy city street, but reducing the amount of noxious fumes and dirty air that you breathe in is always a good thing to consider.
Plus, it is encouraging to see researchers look at how cyclists can stay safer on the road in a holistic way. Progress like this is always a good thing, when it means people are helping cyclists to stay safe and healthy, which is what we are all working towards!
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