Sadiq Khan issues 'very high' air pollution alert in London
The very first 'very high' pollution alert has been issued in London by mayor Sadiq Khan.
The warnings are being issued at bus stops, tube stations and roadsides in London.
Episodes of pollution with high concentrations occur a few times per year in London, but very high pollution episodes are rare.
High and very high levels of pollution can cause people with asthma to need to use their inhaler more.
In the capital, the London Air Quality Network run by King's College, London, said the cold, calm and settled conditions over the weekend caused a build up of local emissions from traffic and wood burning, combined with pollution from the continent.
Very high levels of particulates are expected through Monday in London and into Tuesday, with highest levels of pollution expected in the centre of the city and along busy roadsides.
Here are London's most polluted areas with Camden, the City of London and Westminster ranked very high.
10 - Camden
10 - City of London
10 - Westminster
9 - Ealing
9 - Kensington and Chelsea
9 - Richmond
8 - Enfield
8 - Greenwich
8 - Redbridge
7 - Brent
7 - Lambeth
7 - Lewisham
7 - Tower Hamlets
6 - Bexley
6 - Croydon
6 - Havering
6 - Reading
6 - Southwark
6 - Sutton
6 - Thurrock
6 - Wandsworth
5 - Hackney
5 - Windsor and Maidenhead
4 - Barking and Dagenham
4 - Hammersmith and Fulham
4 - Kingston
3 - Islington
3 - Reigate and Banstead
3 - Sevenoaks
2 - Brentwood
2 - Castle Point
1 - Haringey
0 - Merton