Emissions research from King's College London has found nitrogen dioxide concentrations on Oxford Street to be worse than they are anywhere else on Earth, in the history of air pollution. David Carslaw, who led the research, said: "To my knowledge this is the highest in the world in terms of both hourly and annual mean." That's higher than Beijing and Dhaka, higher than anywhere where face masks are the norm and the streets seem to throng with lost medics, and more than 11 times the EU limit.

A spokesman for the mayor of London called the figures "misleading", and said that the capital's air pollution was lower than that in many world cities. The fact is, there is too much stop-start traffic, too many tall buildings, too much nitrogen dioxide. But if you were more interested in winning a debate than you are in the air your fellow Londoners were breathing, you could see this as room for manoeuvre.

I met a consultant for Transport for London recently who was very keen on this art project: a clean white canvas, with "fresh air" painted in a light glue across the middle of it. You'd stick it up in Vauxhall Cross, in central London, and over time the "fresh air" would go completely black. I wasn't wild about the idea, on the grounds of urban morale. What are you going to do, as you watch your local canvas get darker and darker, and imagine what that is doing to your internal workings? How will that help?

And yet, arrested by these figures, although unsurprised by them – having cycled down Oxford Street often enough to have seen the diesel fumes shimmering in the sun – I think there probably are things we can do.

First, learn to love the EU, without which we would have no statutory pressure at all, just a breezy mayor saying that everything is under control. Nobody is entirely solid on what David Cameron's plucky little Englander routine was meant to convey, so nobody really knows what rights, exactly, the Eurosceptics want to repatriate from Europe. And yet those who defend the EU do so mainly on the basis that its opponents are irrational. It would be preferable to embrace it for some positive reason: that it takes some long-term interest in the wellbeing of the people of Europe, for no better reason than that's what politics is supposed to be about.

Second, we should feel emboldened to make the incredibly obvious connections. Even though a parliamentary environment audit committee estimated in 2010 that the UK was seeing 50,000 premature deaths a year, pollution still isn't taken seriously as a health issue because it lags behind smoking, blood pressure and lack of exercise as a cause of ill health.

Yet, aside from smoking, everything else could be traced back to an obesogenic environment, which is defined as one that "encourages a sedentary lifestyle". The framing is, typically, all about individual choices, your sense of responsibility pitted against your elemental desire to sit on your arse. Don't buy it: what that actually means is the colonisation of public space by vehicles. It has nothing to do with your choices.

It's true that children don't tend to go to school in Oxford Street; yet the fact that only 2% of them cycle to school, compared with 50% in the Netherlands, is attributable to the fact that we don't take road safety seriously across the country. If we did, we would have widespread pedestrianisation. We would have a 20mph speed limit across every conurbation, calming all traffic and reducing the braking and rapid acceleration that have made nitrogen dioxide levels as high as they are. We would consolidate loads on the outskirts of the capital, and drive them in only overnight. If we were serious, in other words, we would make a concerted effort to make all our cities liveable, and stop splitting hairs about which was really damaging our health, between doing no exercise and creating cities in which exercise was undoable.

Third, at some point, we're surely allowed to ask some deeper questions about what this picture tells us. If we have the most polluted main street on the planet, then it is likely that we are taking on characteristics of developing nations: rapid development and urbanisation with insufficient regard for people who live around it, who most probably won't ever benefit from it. In London, the skyline is alive with cranes: the financial services group Deloitte uses words such as "in full swing", but to me the cranes look more predatory than creative. I don't get the sense, when I see another tower of glass, that sometime soon it's going to look like a thriving, mixed community.

We've become so accustomed to the mantra that businesses and developers are king that we've ceased to even make the demand for some kind of equity between their interests and ours.

We're pre-empting the inevitable derision. And that's fair enough: nobody likes to be told no, especially if the refusal is couched in terms that insist upon the pathetic naivety of the request. But these explanations need to be drawn out.

The more we get a Boris Johnson exposition on why the cornflake box must be vigorously shaken for the benefit of the uppermost cornflakes, and how the natural superiority of rich people must be preserved by putting them first at all times, the more widely evident its ridiculousness will be.

The problem with air is that you can't privatise it, so it doesn't deliver a natural political win – either by flogging or protecting it – for anyone but the Greens. But it does tell you quite a lot about the ambient political atmosphere, which right now is pretty toxic.

Twitter: @zoesqwilliams