According to a team at Birmingham University, research indicates a link between high levels of pollution from cars and thousands of deaths from pneumonia.

Scientists examined death rates from the disease and pollution levels in 352 local authorities between 1996 and 2004 and engine exhaust emissions were one of the pollutant levels analysed; the figures were then cross-checked with a range of pollutant levels.

The researchers say while other social factors may also play a part, a “strong correlation” between the two was observed.

They made their calculations by looking at how many deaths there were in each locality in excess of the national average.

The Birmingham scientists found a total of 386,374 people died of pneumonia during the eight year study period but significant regional variations were seen, with Lewisham in London with the highest number of deaths per capita and Berwick-on-Tweed the lowest.

In the 35 local authorities with the highest rates of pneumonia, there were 14,718 more deaths than the national average, and the researchers say these areas also tended to see higher rates of some cancers, chronic obstructive pulmonary disease (COPD) and rheumatic heart disease.

Professor George Knox, the author of the report says high mortality rates were seen in areas with elevated ambient pollution levels and the strongest single effect was an increase in pneumonia deaths.

Professor Knox says the chief source of the emissions was road transport but it was not possible to discriminate between the different chemical components.

The research team estimate that the annual number of excess deaths which could be attributed to pollution could equate with those from the 1952 London smog, which killed 4,000 people.

Environmentalists say the research highlights the need for traffic congestion and pollution to be urgently addressed.

The study is published in the Journal of Epidemiology and Community Health.