Air pollution: Forecasters predict cleaner air on Friday
4 April 2014 Last updated at 06:58 BST
Recent high levels of air pollution over parts of the UK could ease of Friday as "clean Atlantic air" blows in, according to forecasters.
Government data showed London and south-east England had the maximum pollution level of 10 on Thursday.
Levels in eastern England reached nine, with north-west England, Yorkshire, the Humber, the Midlands and south Wales also affected.
Chris King reports.