Is city cycling bad for your health?

If you ride your bike in the city you probably think you are doing good things for your health. Cycling is obviously great exercise but it means that you are out and about in the pollution of a city. So is cycling in the city good or bad for you?

The first study looked to see how much pollution city cyclists absorb and comes from the journal Environmental Science & Technology. This study involved researchers studying the breath of cyclists in Portland, Oregon who rode on either off-street bike paths, local streets, or main roads. Using pollution detectors mounted on the bikes they found that on-road exposure levels to volatile organic compounds was 100 to 200 per cent higher in heavy traffic areas. Breath analysis showed that these VOCs in the breath were between 40 and 100 per cent higher in these high traffic areas too. So you are absorbing significantly more pollution when you cycle but is it enough to offset any benefits you get from cycling?

Based on their analysis they found that only one per cent of cities at the highest end of the World Health Organisation's Ambient Air Pollution Database had pollution levels high enough that the risks of air pollution would outweigh the benefits of cycling for half an hour every day.

This is exactly what was studied in a second study published in the journal Preventive Medicine. In this study researchers from the Universities of Cambridge and East Anglia used computer simulations to compare the risks and benefits of cycling in cities around the world. Based on their analysis they found that only one per cent of cities at the highest end of the World Health Organisation’s Ambient Air Pollution Database had pollution levels high enough that the risks of air pollution would outweigh the benefits of cycling for half an hour every day. This was true even for Delhi, one of the most notoriously polluted cities in the world.

In a city like London someone would have to cycle for five hours a week before the pollution effects would outweigh the health benefits.

So, for the vast majority of people it seems like bikes are part of the life cycle in cities after all.