Air pollution: High levels continue to affect UK
3 April 2014 Last updated at 12:22 BST
High levels of air pollution are continuing to affect parts of the UK, according to experts.
Data from Defra shows London and the South East has reached the maximum level 10 - meaning very high.
Levels in eastern England have reached nine - meaning high - with north-west England, the Midlands and south Wales also affected.
Aerial footage from the capital shows landmark buildings partially-obscured.