The toxic effects of pollution have been known about for years. "Just two things of which you must beware: Don’t drink the water and don’t breathe the air!" sang 1960s satirist Tom Lehrer.
Over recent decades, though, pollution has dropped down our list of things to worry about, thanks to seemingly more pressing concerns such as climate change, the rise of AI, global conflicts and species collapse.
That doesn’t, unfortunately, mean the problem has expired. Air quality often exceeds safe limits, with far-reaching and crippling effects on our health.
But there’s good news. We can take direct, effective, evasive action. We know this thanks to illuminating new research on what’s going into our lungs – some of it being done by citizen scientists on bikes. You and me, in other words.
I was one of those citizen scientists in 2023. As I cycled every day in and around my home town of York in the north of England, doing my normal routes, a Plume sensor on my handlebars the size of a cigarette lighter analysed the air quality and uploaded data to a research project named the York Air Map.
It also displayed air-quality measurements in real time on an app, Flow 2, on my phone.
And what it told me often induced a sharp intake of breath.
Sometimes the dire figures weren’t so surprising. Train stations, of course, have awfully dirty air. Eleven platforms of diesel engines under York’s vaulted roof, what did I expect?
Other readings came as a shock. Innocent-looking country lanes, far from a main road, might flash red with danger warnings. Yet, on the other hand, a breezy day could produce pollution-free readings even on a main road.
I couldn’t even escape lung damage inside my own house, as I found when recharging my sensor. Sometimes, the living-room air quality was terrible.
At times, closing the window made it better; at others, puzzlingly, that made things worse.
More predictably, when I was stuck at the traffic lights behind a vigorously idling exhaust, the numbers went off the scale.
So what were these figures? Sensors typically display real-time figures for PM1, PM2.5, PM10, NO2 and VOC: the core information about what your lungs will tell you one day if they haven’t already (the damage is slow, imperceptible and insidious).
‘PM’ is ‘Particulate Matter’: “little bits of material… including smoke from fires, exhaust fumes, smoking or the dust from brake pads on cars… we can breathe them in without noticing,” the website Clean Air Hub informs us. PM2.5 measures particles below 2.5 microns across, and so on (a human hair is about 100 microns wide).
PMs are terrible news for your lungs. Picture your vacuum cleaner’s filter after a year of uncleared use 24/7.
‘NO2’ meanwhile is nitrogen dioxide, a nasty by-product of burning fossil fuels. It’s not to be confused with N2O, which is nitrous oxide, or ‘laughing gas’.
Indeed, NO2 is no laughing matter. Along with other nitrogen oxides (often lumped together as ‘NOx’), it ravages your airways in various reactively ingenious ways.
It’s only one of many chemical pollutants in each breath: sulphur dioxide (SO2) for instance, a lively generator of acid rain; ammonia (NH3), copiously generated by farm slurry; the lung irritant ozone (O3); the silent sleeper-killer carbon monoxide (CO) and depressingly many others.
We’re not finished. ‘VOC’ stands for ‘Volatile Organic Compounds’: hazardous fumes given off by chemicals in furniture, paint, varnishes and other interior finishes, plus hairsprays, cleaning products and more. Air quality indoors can be worse than in the traffic jam outside.
Something in the air
We know all this is vandalising our health. Beth Gardiner’s book, Choked, looking at the human cost of air pollution around the world, is an uncomfortable but eye-opening read.
As if the wheezing, coughing and struggling up the stairs wasn’t bad enough, air pollution is strongly implicated in everything from heart conditions to Alzheimer’s.
However, establishing precise links is a scientific challenge. We’re trying to quantify the effects of something tiny, accumulated over decades, amid myriad other potential factors of modern industrial society (processed food, a sedentary lifestyle, microplastics, 5G, non-stick pans, etc, etc…).
And it’s harder when so many vested interests want us to keep driving cars, burning oil, eating intensively farmed meat and buying fireproof sofas.
Look at ULEZ, the scheme that charges polluting vehicles to enter London’s ‘ultra low emission zone’. Those with vested interests have incited public opinion against it, sometimes violently, using misinformation and well-funded, well-targeted press releases and social media activity.
Winds of change
So far, so bad. But what can we do about it? This is where the York Air Map project comes in – and you too.
It’s a world that embraces art and science, nature and technology. It’s a world where a bike ride can be an artistic work, as well as valuable scientific research.
York Air Map is run by two cycling academics: artist Clare Nattress and air-chemistry researcher Daniel Bryant.
They teamed up in 2020 when Nattress was riding the Way of the Roses, a 170-mile coast-to-coast from Morecambe to Bridlington.
She was collecting pollution data en route, and sought expert assessment (as well as analysis of the face mask she wore, one conclusion of which was that face masks offer little worthwhile benefit against bad air).
Nattress's trip wasn’t simply a bike ride with a gadget. It was performative: an artwork. Art is more than creating nice things to look at to pass the time.
The York Air Map project is a fusion, using art to communicate the science.
While riding the Way of the Roses, Nattress stopped every time the pollution monitor showed a danger to health, and recorded the pause with a photo.
Over the three days, that happened 285 times. “The highest reading of PM10s and NO2 was in the middle of the Yorkshire Dales,” she recounts. “In the middle of fields, and 360-degree scenery!”
Other travel experiences have shown Nattress the global gravity and complexity of the pollution problem.
While cycling round the world with her partner in 2018–19 (on Bombtrack bikes, since you ask: see their YouTube video ‘Lost Captures’) the most dangerous atmosphere she breathed was in Nepal, and the cleanest in Tasmania.
Not that wind cares about human geography. Pollution can be transported anywhere. And is.
Bryant’s cycling is more the utility kind – zipping round York University campus to the Wolfson Atmospheric Chemistry lab, a facility involving 80 or so researchers.
He’s passionate about the knowledge-exchange aspect of his work: how do we articulate often complex science to a general audience, particularly policy makers?
Positive change, he says, will ultimately only come from consumer-driven demand.
Making that happen, having an influence, is not simply a matter of presenting facts, figures, stats and graphs.
Which is where the York Air Map comes in. Already there’s a colour-coded map of hotspots around the city to avoid at certain times of day or days of the year, and the data is being consolidated all the time by the citizen scientists.
The sensors are not very accurate – Daniel talks about it as 40 per cent – but the more data, the more we can weed out the dodgy readings. We have to take individual figures with a pinch of salt.
No change too small
Conscripting us proved easier than Nattress and Bryant expected – a few notices and the odd talk to the local cycle campaign, and willing volunteers queued up.
Lots of us, it seems, enjoy the idea of turning the effectively free resource of our regular cycle trips into something that advances scientific knowledge.
I often went out for an extra ride or took a different way route from usual, knowing it would provide useful data.
York Air Map’s funding comes from a variety of one-off academic and governmental grants; it’s proved enough so far, but it’s irregular, making long-term planning tricky.
If Bryant’s focus is on policy, pragmatics, and systemic change, Nattress talks a lot about personal agency, about enabling us to make decisions that benefit us.
As she says, compared to say climate change or microplastics contamination, it’s easier to make changes to help ourselves directly.
She points out that a small positive change over time – a commuter avoiding that particular stretch of road and that exact junction every day for instance – can have a strong cumulative effect. The York Air Map informs us to achieve that.
It made me realise how localised patches of harmful air can be. Right behind the exhaust of a car idling at the lights, the readings could be showing a red-alert, while just a few yards away on the footpath, the nasty stuff had dispersed to tolerable levels.
Don’t pay too much attention to the one-size-fits-all ‘air quality’ figures on weather forecasts: York may well be in for a day of clean air generally, but the cyclist’s Advanced Stopping Line at Bootham Bar traffic lights can still be like a Saturday night pub, pre-smoking ban.
Citizen science has other bike-safety applications. In Germany, the Open Bike Sensor project supplies cyclists with gadgets that measure passing distance of vehicles. It doesn’t identify individual vehicles, so there’s no data protection concerns or accusations of ‘vigilantism’.
Like the York Air Map, they hope the data gathered – in particular, about trouble hotspots – can help inform policymakers in an unbiased way to bring about the changes necessary to make things safer for all of us.
A cleaner, more sustainable world will only come about through coordinated global policy change. Don’t hold your breath. But meanwhile, the York Air Map and other projects are showing that some winds of change might just blow in our favour. And maybe you can help them, just by riding your bike.
