It must look as though I am a thief, or at the very least up to no good. You see, I can no longer expose my lower face to the streets of London. When I was younger, and Converse soles beat city streets, I’d hop from bar to bar exposing many things: legs, torso, an adolescent need for acceptance, a too-high tolerance for alcohol.

Now, walking on city pavements, it feels as though I have put an exhaust pipe in my mouth and sucked hard, like the final cigarette I had. I have gone from mocking tourists who wear masks – looking as though they are about to embark on vigorous floorboard sanding – to browsing shops for similar.

Of course, the campaign for clean air has been significantly harmed by white people with dreadlocks and dudes with This Machine Kills Fascists stickers. But fill in your postcode on a government website and it will tell you exactly how much your child will be choked on her way to school, the daily filth fillings her lungs. Not to be a downer, but the World Health Organisation has estimated that air pollution kills 7 million people a year worldwide. OK, that is quite a downer.

For those of us who live in cities, arriving in the countryside is… well, I imagine it is how footballers feel when they sleep in hyperbaric chambers. Like being held underwater, guttering, choking, drowning, to quote Wilfred Owen, and then bobbing up cork-like. The country roads I moaned about on trips as a kid, the stench of cow pat, the scratches from brambles, are a small price to pay now for the absence of diesel taste on the tongue. How much I love the wind whipping up the salty ether of the Cumbrian coast and dissipating the tense, muscular knots of responsibility.

A Canadian company is even selling compressed air from the Rocky Mountains. The jars hold (apparently) about 160 breaths and cost $32, about £20. Orders are big from India and China. Quitting fags made me crave better and bigger breaths because when the cilia in my windpipe started to work again, I realised what I had been missing. You don’t know what you haven’t got until it returns.

Finland, I have learned, has the best air quality in the world. Of course it does. Finland is the best at everything. Finland is the straight-A student who never even bothers to revise. I want to go to Finland then, sit on the edge of a lake with my feet in the water and gulp for eternity.