Tens of thousands of people are dying early because of where they live - and the government is not doing enough to address the problem, a report has said.
Rising air pollution levels are blamed on traffic
The Royal Commission on Environmental Pollution says obesity, air pollution and traffic accidents all contribute to lower life expectancy.
The report says these problems are worse in towns and cities - where 80% of the UK population now lives.
It calls for an "over-arching" strategy on urban environments and health.
Members of the commission visited 11 British cities and towns to conduct their research, including Edinburgh, Swansea and Belfast.
FACTS OF URBAN LIFE
24,000 premature deaths from air pollution in one year
Urban residence linked to prevalence of psychiatric disorders
Some disease transmission rates higher in urban areas
And they concluded that the stresses and strains of urban living contribute to tens of thousands of deaths each year.
They say in 1995-96 air pollution resulted in 24,000 people dying on average eight to 10 months earlier than they would have done.
The report says: "Major issues include climate, obesity and mental health.
"Most of these problems are not unique to urban areas, but are important because of the high numbers of people living there and the aggravating impact of factors associated with urban areas, such as high levels of vehicle emissions, poor housing and a lack of good quality green space."
Members of the commission were "astonished" to find the government did not have an over-arching strategy to deal with the pollution impact of housing, transport and energy use in towns and cities.
Commission chairman Sir John Lawton said: "Urban air pollution, for example, is now on the increase again, particularly because of the increase in the number of vehicles on the roads.
"Government has consistently failed to address that."
House building warning
He said he feared the government was not taking seriously the environmental aspects of the large-scale house-building plans in the South East of England.
"We are not convinced that the government have grasped the scale of the issues that confront them in building new areas in the South East.
He said the issues were "in water supply, in the adequate provision of public transport and the whole design of these areas so people can get about more easily without using their cars".
The report said some positive initiatives were being taken in individual areas, such as London Mayor Ken Livingstone's congestion charge scheme.
The Department of Communities and Local Government pointed out that the RCEP report had been three years in the making.
It said over the same period government activity included new policies on sustainable development and climate change, a timetable towards zero carbon homes, and emphasis on more parks and green spaces.
A spokeswoman said: "It is a shame such changes could not have been considered in the report,
"However, it is a welcome contribution to the debate and the government will respond in due course."