More needs to be done to protect people from harmful air pollution, health officials have said after new estimates suggest thousands die every year as a result of poor air quality.
In London there were 3,389 deaths in 2010 of people over the age of 25 attributable to air pollution, with 155 of these in Croydon and 92 in Sutton.
Public Health England (PHE) said long-term exposure to air pollution led to around 25,000 deaths in England during that year.
Last week swathes of England and Wales suffered extremely high pollution levels.
The dip in the air quality was caused by a combination of dust from the Sahara Desert, emissions from the continent, low south-easterly winds and domestic pollution.
A fresh air mass pushed the pollution away from Britain last Friday.
Health officials said that the latest estimates are for long-term exposure to pollutants, not short-term exposure to poor air quality as seen last week.
But they said short-term exposure can cause a range of adverse effects such as exacerbation of asthma and effects on lung function.
The estimates are calculated using the average annual concentrations of man-made particles less than 2.5 microns in diameter, and the impacts on health.
PHE said that air quality has improved "considerably" in the UK in recent decades due to new cleaner technology and tighter environmental legislation.
But it said that local action can be taken to reduce the emissions of these man-made particles and people's exposure to air pollution.
PHE's director of health protection and medical director Dr Paul Cosford said: "Policies that encourage a shift from motorised transport to walking and cycling would be expected to reduce total vehicle emissions, including particulate pollution.
"If this could be achieved in towns and cities, then we could expect local improvements in air quality. There would also be health benefits from increased physical activity through walking and cycling.
"Local authorities could also consider other measures to improve air quality, such as implementing low emission strategies as well as the appropriate design of green spaces."
And British Lung Foundation chief executive Dr Penny Woods said: "With the high levels of pollution we experienced last week there has been a lot of discussion about the short-term effects it can have on people's health, particularly to those living with a lung condition.
"However, this new report further highlights just how serious exposure to pollution can be to people's health in the long-term - this is something we urgently need to tackle."