Prof Frank Kelly of the environmental research group at King’s College London warned us that “we have this new problem that we cannot see: it is tiny particles of nitrogen dioxide.” But the health impact of poor air quality in the UK, which is among the worst in Europe, is clear for all to see.

Kelly estimates that about 30,000 people died from air pollution in Britain in 2008, with individuals “losing on average three years of their life.” In London, where the Green mayoral candidate Jenny Jones is putting press on Boris Johnson to act urgently on air quality, the mayor’s own health impact study estimated that the equivalent of 4,267 deaths in 2008 were attributable to long-term pollution.

Road traffic emissions are still the primary culprit, due to the quantity of particulate matter (PM10) and nitrogen dioxide (NO2) – and also due to the way in which traffic permeates our towns and cities. Pollution from vehicles is released directly into our streets at a low height level, where it has little opportunity to disperse before being inhaled by those who live and work in heavily populated urban areas.
Caroline Lucas, MP

30,000 is a very big number – it’s about 5% of all deaths.

And by coincidence, 30,000 is about the same as the number of people killed and seriously injured by accidents on UK roads each year.

So it goes.