London faces new smog threat from switch to diesel fuel

London has a dirty secret.

Levels of the  air pollutant nitrogen dioxide at a city-centre monitoring station are the highest in Europe. Concentrations are greater even than in Beijing, where expatriates have dubbed the city’s smog the airpocalypse. 

It is the law of unintended consequences at work.  EU efforts to fight climate change favoured diesel fuel over  petrol because it emits less  CO2.  But diesel’s contaminants have overwhelmed the benefits from other measures that include a toll  to  drive in central London, a  bike-hire programme and  better public transport. 

“Successive governments knew more than 10 years ago that diesel was producing all these harmful pollutants, but they myopically  ploughed on with their CO2 agenda,” said Simon Birkett, founder of Clean Air in London. 

“It’s been a catastrophe for air pollution, and that’s not too strong a word. It’s a public health catastrophe.”

Tiny particles called PM2.5s probably killed 3,389 people in London in 2010, the government agency Public Health England said  last month. Like nitrogen dioxide, or NO2, they come from diesel combustion. Because the pollutants were found together, it was hard to identify deaths attributable only to NO2, said Jeremy Langrish, a clinical lecturer in cardiology at the University of Edinburgh.

“Exposure to air pollution is associated with increases in deaths from cardiovascular disease such as heart attacks and strokes,” Langrish said. “It’s associated with respiratory problems like asthma.”