Regular exercise is needed to remain fit and healthy, but the rise of pollution in major cities across the world brings risks.
At the end of January 2018 London had already reached its legal air pollution limit for the entire year.
Exercise, like running outdoors, requires increased levels of oxygen.
London’s pollution, made up of heavy metals from tires and diesel fumes, can be damaging to your lungs and heart. It increases the chance of heart attacks, strokes, and even dementia, and people who run outside are exposed to this.
People run every day in London, from the marathon to a weekly jog, but pollution in the air means theIR exercise may be doing more harm than good.
On days with high levels of pollution, running around London has its risks. King’s College, London, has been monitoring air quality and publishing their forecasts, so people can see the air quality in their area.
To ensure runners are careful, they recommend choosing particular times of day and locations to prevent increased pollution levels. Avoiding running along a busy road, for example, is important.
Last year during a time of high pollution, Mayor of London Sadiq Khan tweeted recommending everyone to reduce physical exercise:
This is the highest level air quality alert. Everyone, from the most vulnerable to the physically fit, may need to reduce physical exertion.
— Mayor of London (@MayorofLondon) January 23, 2017
Khan has made the problem of pollution central in his governance, and recently saw his 2016 manifesto pledge to pedestrianise Oxford Street to “restore London’s air quality to legal and safe levels” blocked by Westminster Council.
The British Heart Foundation recommends avoiding spending a long time in polluted areas, especially at rush hour, but running outdoors means more time outside.
They say that the benefits of physical activity outdoors outweigh the risks, but advises people to be as active as they can indoors – especially on days with high pollution.
Over the past five years, there has been a slight decrease in pollution in London from vehicles.
Looking at certain gases that tend to be created by vehicles, we can see that despite a rise in 2016, pollution levels are down significantly since 2012.
Even though pollution is decreasing, its already high levels means there is a long way to go until running in London will be risk free for health.
Images and video: Clare ClarkeStatistics in video taken from Strava and BBCGraph looks at nitric oxide, nitrogen dioxide, oxides of nitrogen, ozone and sulphur dioxide pollution in London over the past five years from information provided by King's College London.