Norwich has been identified as one of 32 cities around the country exceeding air pollution levels.
The World Health Organisation (WHO) data shows the areas have fine particle air pollution levels above its limit of 10 micrograms per cubic metre.
Norwich has a score of 11, the body says, and is joined on the list by cities including Thurrock, Leeds, Liverpool and London.
Port Talbot, in Wales, has the highest figure at 18.
Fine air particle pollution is linked to diseases including stroke, heart disease, lung cancer and respiratory infections, the WHO says.
The report said that seven million people a year are dying due to poor air quality, and nine out of 10 people worldwide are exposed to levels of air pollution that are dangerous to their health.
Particular areas in Norwich have been identified as having especially high levels, such as Castle Meadow in the city centre, which has several bus stops.
Simon Gillespie, chief executive of the British Heart Foundation, said: 'The UK Government needs to show leadership by adopting WHO air quality guidelines into national legislation and in doing so, help to protect the nation's heart and circulatory health.'
Alison Cook, director of policy at the British Lung Foundation, said: 'This report reconfirms that air pollution is one of the leading environmental public health crises in the UK today.
'Action to reduce the toxic particles in the air we breathe can no longer be delayed.
'How much more evidence do we need to see before the Government sets new legal limits on pollution levels to protect the nation's lung health?'
A Defra spokesman said: 'While air quality in the UK has improved significantly since 2010, this report from the WHO clearly shows the impact air pollution is having on the health of men women and children in the UK and across the world.
'Tackling this important issue is a priority for this government which is why we have a £3.5bn plan to improve air quality and reduce harmful emissions and will set out further actions through a comprehensive Clean Air Strategy later this year.'
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here