Dirty Old Town

Four of the capital's five worst roads for air pollution pass through some of the poorest areas of east London. In west London and the wealthy stockbroker belt the air is cleaner, with roads in Weybridge, East Molesey and Esher the cleanest of the 41,713 recorded last year.

Air pollution from traffic is linked to strokes, heart and respiratory diseases as well as some cancers and asthma. About 4,300 premature deaths a year are attributable to air pollution. Parliament's environmental audit committee estimates that outdoor air pollution causes 29,000 deaths a year in the UK, compared with fewer than 2,000 a year caused by road traffic accidents.

London has the highest levels of nitrogen dioxide (NO2) of any capital city in Europe. Fifteen other British cities and regions – including Manchester, Birmingham and Glasgow – are heavily polluted by traffic and, according to the government, are not going to meet the legal requirements for lowering emissions for at least seven years.

Last month the supreme court ruled that Britain was in breach of EU law on NO2 emissions from exhausts. The case will now be heard in the European court of justice, and the government could face stiff fines.