How dangerous is the air where you live? UK's most polluted towns and cities revealed

Millions of people in the UK are inhaling air considered too dangerous to breathe by the World Health Organisation (WHO), a report has revealed.

WHO's air quality database showed 44 out of 51 British towns and cities had failed its tests for fine sooty particles smaller than 2.5 microns across.

The particles, known as PM2.5s, have been linked to causing heart disease and premature death and they should not exceed 10 micrograms per cubic metre of air, according to the organisation.

But a significant number of places exceeded the amount required to keep air safe.

Dr Toby Hillman, one of the report's authors from the Royal College of Physicians, said: "There isn't a safe limit for the amount of pollution that's been defined as yet and we know the effects of poor air quality run from cradle to grave; it's a lifetime threat to human health.

"This is a really direct and tangible impact on UK health from the drivers of climate change, and taking action on air quality should be a priority."

:: Here is a list of the worst places in the UK for air quality according to average annual PM2.5 numbers (in micrograms):

Glasgow - 16

Scunthorpe - 16

Eastbourne - 15

Leeds - 15

London - 15

Salford - 15

Southampton - 15

Armagh - 14

Birmingham - 14

Cardiff - 14

Chepstow - 14

Gibraltar - 14

Oxford - 14

Port Talbot - 14

Portsmouth - 14

Stanford-le-Hope - 14

Stoke-on-Trent - 14

Thurrock - 14

Warrington - 14

Bristol - 13

Leamington Spa - 13

Manchester - 13

Newport - 13

Norwich - 13

Wigan - 13

Belfast - 12

Carlisle - 12

Hull - 12

Liverpool - 12

Nottingham - 12

Plymouth - 12

Prestonpans - 12

Swansea - 12

York - 12

Birkenhead - 11

Brighton - 11

Londonderry - 11

Middlesbrough - 11

Saltash - 11

Southend-on-Sea - 11

Chesterfield - 10

Newcastle upon Tyne - 10

Reading - 10

Stockton-on-Tees - 10

Wrexham - 10

Aberdeen - 9

Bournemouth - 9

Grangemouth - 9

Sunderland - 9

Edinburgh - 8

Inverness - 6