Increasing numbers of people in cities are walking or cycling to work to get fit. But many have been asking the question: ‘Is it actually healthier when I have to breathe in all that air pollution?’ Now, a study published in the Journal Preventative Medicine has attempted to answer this question.
Unsurprisingly, the results depend on where you live. The good news is that, for the majority of cities around the world, walking or cycling to work will benefit your health. Though, that may be bad news if you are looking for an excuse to ditch the lycra and jump back into your car.
The study compares the risk-benefit trade-off for a range of air pollution concentrations and active travel scenarios (hours of walking or cycling). For the global average urban background concentration of fine particulate matter (PM 2.5 = 22 μg/m 3 ), benefits of physical activity by far outweigh the risks from pollution, even under the most extreme levels of active travel.
However, there are a few exceptions. Six of the most polluted cities in the world are in India, with a further three in Pakistan. Active travel in these cities would be more harmful than beneficial after only an 1 hour 30 minutes per day, or less than 1 hour a day in the dirtiest city Delhi (PM 2.5 > 150 μg/m 3 ).
That is no excuse for the rest of us though. In London, for example, where levels of pollutants are much
Slower, it is always better to walk or cycle than take public transport or a car. What’s more is that by doing so you will be helping to reduce the levels of air pollution – a win-win for everybody.