Killer cars
Traffic pollution has been linked to thousands of deaths from pneumonia.
British researchers are suggesting that high levels of pollution may have contributed to the deaths in recent years of thousands of people in England from pneumonia.
According to a team at Birmingham University in the Midlands, their research indicates a link between the two.
The 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 crosschecked 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.
The made their calculations by looking at how many deaths there were in each locality in excess of the national average.
The scientists found that 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.
They say more detailed research needs to be carried out into the impact of air pollution before it is clear that exhaust fumes are linked to increased deaths from pneumonia.
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 that could be attributed to pollution could equate with those from the 1952 London smog, which killed 4,000 people.
Experts say more detailed research is needed before a clear link between pneumonia and exhaust fumes can be declared.
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.
