Over 56,000 people ran the London Marathon last weekend. We were out supporting - a wonderful atmosphere and congratulations to all the runners!* Unfortunately they were subject to unexpectedly high levels of ground-level (or tropospheric) ozone and wider pollution warnings.
Ozone is one of the less talked about pollutants - but we did cover it here. In the UK we are a bit less susceptible to it, but famously cities like Los Angeles - with all those exhaust fumes mixed with sunlight - suffer regularly from high levels of ozone.
Ozone can irritate your airways - and long-term exposure can aggravate respiratory conditions. It can immediately affect athletic performance - so if anyone reading this completed the marathon in a slower time than expected, this could be part of the story. Some have made the case that runners can acclimate to higher ozone (anyone preparing for the LA Olympics may wish to read the evidence carefully…) but others argue that the long-term damage this wilful exposure to ozone can do is not worth it.
Primary leads to secondary
So what can we do? The main thing is to reduce the nitrogen dioxide (NO2), so that the secondary pollutant of ozone can’t be created in the first place. The London Mayor has been reporting a 27% drop in NO2 as a result of the expansion of the Ultra-Low Emission Zone (ULEZ). This is great news, though we do still see very high readings at our Brixton monitoring node. Happily Sadiq reminded us of the improvements as we were leaving our marathon viewing at Tower Hill station…
London isn’t the only one. The great competition with Paris continues. Recent reports have talked about a 50% reduction in NO2 over the past two decades, as a result of radical policies to reduce traffic. This video has a great explainer including these images which we’ve seen doing the rounds a lot recently!
It’s not just the impact of the environment on runners, but the impact of marathon runners on the environment. Such a huge event inevitably has an impact - plastic water bottles, the logistics of transporting everything from the start to the finish line, the temporary loos, the branded t-shirts - you name it. London Marathon Events has just won a recognition of its sustainability work including loaned medals, collecting and re-using urine for fertiliser and offsetting the runners’ carbon impact from travel.
*If we were enjoying the marathon so much, why no photos? We just thought you didn’t need to see another photo of kids eating ice-cream while pained runners were coming up to mile 22….