For those of us who like to exercise outside, pollution is a growing worry – especially for those who live in cities.
Over the past few years, the research into the damage that pollution can do – not only to our lungs but to our whole self – has been very scary indeed. Scientists believe that 7 million people around the world die from pollution every year. For a figure that you're better able to understand: a report out of Bristol earlier this week found that five people a week in the city are dying from pollution-related issues.
Beth Gardiner is a journalist whose (incredibly readable) book on pollution, Choked: The Age Of Air Pollution And The Fight For A Cleaner Future, calls out London in particular. "London," she writes, "has a serious nitrogen dioxide problem, because the pollutant pours from the diesel cars Britain has foolishly encouraged people to buy." She uses the example of Frank Kelly, head of the Environmental Research Group at King’s College London who, when he started to look into the physiological effects of pollution in the 1990s, found that dead Londoners' lungs "were too compromised" even to study. London, he told Beth, "is a gas chamber".
Which is all very cheery news. Especially for those who, in lieu of increasingly expensive gym memberships, like to exercise outside. My run home takes me through Southwark, which lays claim to two of the top 10 most polluted areas in the city, and sometimes when I walk through my front door after my hourlong run, eyes streaming, nose running and chest tight, a thin veil of grime on my skin and in my hair, I feel anything but healthy. So my question is...is it really worth it? Pollution, as we now know, has an effect on nearly every organ in the body and has been linked to everything from Alzheimer's to diabetes to brain cancer. Is it possible I'm doing more damage to my body than good?
It’s a complicated one, says Andrew Grieve, the senior air quality analyst at King’s College London, who actually works under Frank Kelly. They’ve teamed up with Tenzing - a natural energy drink -to launch the Clean Air Tracker, which helps runners map out less polluted running routes around the city. "Are runners particularly at risk?" he asks. "On the one hand, you say 'yes' because obviously, when you’re running, you’re breathing a lot more than you are just walking along the street and your inhalation rate is massive so you’re bringing in more pollution." The difference in how much you’re breathing in is a lot; someone running a marathon will inhale the same amount of oxygen as a normal person would sitting down over two days. But before running-phobes get too excited about hanging up their trainers for good, he’s not done. "On the other hand, running and exercise is good for you..."
Andrew isn't aware of any studies into running and pollution but he does cite a study done on cyclists in Barcelona which weighed the cardiovascular health benefits from cycling against the slight increase in exposure to pollution that cyclists experience. The health benefits won. "Regarding running, I imagine that the health benefits of running would outweigh the disbenefits of extra exposure to pollution." He continues: "Running is good for you, exposure to pollution is bad for you. The best thing you can do is run in low pollution areas."
This turns out not, as I had expected, to include a trip to the countryside. For instance, just swerving off the heavily polluted Old Kent Road and taking the quieter roads behind will have more impact than I previously thought. "I’ve measured a lot [of air pollution levels] of backstreets across London," Andrew says. The difference from the main road to just one block back was on average about 50% less pollution – which is a lot. "I’m so dismayed to see people jogging up and down Euston Road and Marylebone High Street at lunchtime," he says. "Why would you run there when Regent’s Park is right there!"
He warns of summertime ozone episodes. "If it’s really sunny, then [the pollution] is going to start to build up from the morning and peak between four and six in the evening." The time, I note, that most people will be running home. "My advice is then in the summer to do it in the morning – so you can avoid that late afternoon peak." Boo.
What about masks? I ask. Early anti-pollution masks were derided as being useless but some of the contraptions I see people wearing on the Tube these days look positively space age. Dr Gary Fuller, one of Andrew’s colleagues who writes Pollutionwatch for the Guardian, says that how good your mask is depends on many things, including how well it fits, whether the user has facial hair which could prevent a good seal, the shape of the user's face and, indeed, if you’re even able to run while wearing something that makes it harder to breathe!
In short, don't stop working out or running outside if it's the type of exercise you love and a type of exercise that works for you. Finding something you're able to do regularly and willingly to help your cardiovascular health is incredibly hard to do.
But do your best to plan a route that deliberately avoids highly polluted areas – making sure you stick to safe routes, especially if you're running in the evening, in the dark, when many parks are closed and streets are in darkness. Check the Clean Air Tracker, check the London Air website and, if you can bear it, do your running in the morning.