Cycling is becoming more popular in cities across Europe, Asia, Oceania and the Americas. There are now more than 500 bicycle-sharing schemes around the world and the number continues to grow. Spain is one of the countries with the largest number of bike-share systems. Barcelona’s Bicing, with 6,000 bicycles, is one of the world’s best-known systems, and Madrid recently launched BiciMAD, a system with 1,560 electric bicycles. But how safe is it to ride a bike in a city? Does air pollution make urban cycling unsafe? These are questions that many people have pondered while pedalling.
To answer these questions, we must first understand the dangers that cyclists are exposed to. European research projects such as TAPAS have identified the most common risks faced by urban cyclists, including air pollution and traffic accidents, as well as benefits like physical activity. For a given journey across a city, a cyclist engages in more physical activity and therefore inhales more polluted air than a person travelling in a car. Cyclists are also exposed to a greater risk of being involved in a traffic accident. However, people who ride a bicycle every day enjoy the health benefits associated with getting more exercise.
The benefits of physical activity outweigh the risks associated with air pollution and traffic accidents What happens when we consider these three factors together and weigh the risks and benefits of cycling? Several studies carried out in different countries have sought to answer this question, and they have all reached the same conclusion: The benefits of physical activity outweigh the risks associated with air pollution and traffic accidents. One such study, conducted in Barcelona, assessed the impact of the Bicing bike-share system on people’s health. The researchers found that the risk of death from pollution and traffic accidents is 70 times lower than the exercise-related benefits enjoyed by cyclists.
Choosing a better route can reduce exposure to pollution by up to 60%"
How to Reduce Exposure to Pollution?
These findings lead to another question: Is there anything cyclists can do to reduce their exposure to pollution? Some people wear anti-pollution masks, but is that really the best solution? Recent studies have evaluated the protective effects of these masks, particularly their ability to filter suspended particles, the most dangerous type of airborne pollutant. These studies have found that the commercially available masks for urban cyclists protect wearers from the largest particles but do not filter out smaller particles or certain gases found in polluted city air. So, instead of wearing masks, what should cyclists do to avoid polluted air? Choosing a better route can reduce exposure to pollution by up to 60%. Riding on roads with less motor vehicle traffic can reduce cyclists’ exposure to polluted air as well as their chances of being involved in a traffic accident.
Some solutions are up to the individual cyclist, but the best way to reduce exposure to pollution and risk of accidents is for cities to provide cycling infrastructure such as safe, segregated bike lanes. Even more effective at improving health—of both cyclists and the general population—are public policies that help to reduce the number of cars on city streets. Getting people to walk, ride a bike or take public transit instead of driving can reduce traffic congestion and greenhouse-gas emissions.
The PASTA study team members, at CREAL's facilities.
The Centre for Research in Environmental Epidemiology in Barcelona is currently conducting a study called PASTA (@PASTABCN on Twitter)that aims to determine how factors such as choice of route, mode of transport (bicycle, car, public transit or walking), and urban design can affect health. Epidemiologic studies have answered many of our questions, but many others remain unanswered. If you’d like to help answer new questions, you can register here and join us as a volunteer.