St Paul's Cathedral and the Shard seen through the smog from Primrose Hill in north London. Photograph: Daniel Leal

Slough, London and Leeds among worst locations on map showing air pollution above WHO limits

Virtually every home in the UK is subjected to air pollution above World Health Organization guidelines, according to the most detailed map of dirty air to date.

More than 97% of addresses exceed WHO limits for at least one of three key pollutants, while 70% of addresses breach WHO limits for all three.  ...