New study links pneumonia deaths with pollutionIt blames thousands of deaths on fumes

15 April 2008

Thousands of people have died in recent years from pneumonia caused by pollution, a study out today suggests.

There is a 'strong correlation' between the deaths, engine exhaust fumes and other transport-related substances, it said.

Details on atmospheric emissions, published causes of death and expected causes of death were examined for the research.

Pollution and death rates

The data, which came from 352 local authority areas in England between 1996 and 2004, were used to calculate the impact of pollution on death rates.

In total, 386,374 people died from pneumonia in the whole of England during the eight-year period but there were widespread regional variations.

In the 35 (10%) local authorities with the highest disease-specific death rates, there were 53,821 pneumonia deaths.

This was 14,718 more pneumonia deaths than the expected national rate, the study showed.

'Strong link'

Calculations revealed that pneumonia, peptic ulcer, coronary and rheumatic heart diseases, lung and stomach cancers and other diseases were all associated with a range of combustion emissions, as well as social deprivation, smoking, binge drinking and living in the North.

When the social factors were taken into account, the data still revealed that deaths from pneumonia were strongly and independently linked to emissions, with the exception of sulphur dioxide from coal burning.

Professor George Knox, emeritus professor at the University of Birmingham, carried out the study which was published in the Journal of Epidemiology and Community Health.

Correlations with pneumonia deaths were exceptional

He wrote: 'Correlations with pneumonia deaths were exceptional.

'High mortality rates were observed in areas with elevated ambient pollution levels. The strongest single effect was an increase in pneumonia deaths.

'Road transport was the chief source of the emissions responsible, although it was not possible to discriminate between the different chemical components.'

London smog

He said many of the pneumonia deaths were probably caused by 'direct chemical injury,' as in the 1952 London smog, which killed 4,000 people.

'Total annual losses as a result of air pollution, through pneumonia, probably approach those of the 1952 London smog,' he said.

Prof Knox said evidence suggests the pollutants directly damage lung tissue because the links are so strong across all categories of exposure and deaths were so much higher than would be expected.

Engine exhaust fumes

He concluded: 'The main finding was a strong correlation between deaths from pneumonia and engine exhaust emissions, together with other transport-related substances. The pneumonia correlations far exceeded those of all other SMR (disease-specific standardised mortality ratios) in every class of exposure, suggesting a direct lung contact injury.

'Excess deaths assigned to COPD (chronic obstructive pulmonary disease) and rheumatic heart disease, two diseases with chronic respiratory inadequacy, can also be interpreted as directly contact toxic.'

Cancer

Prof Knox added: 'The excess deaths from lung and stomach cancers and peptic ulcer are more difficult to interpret but the same pollutants may have acted as adjuvants to other agents, facilitating their access to sensitive tissues.

'The lung cancer and stomach cancer associations were identical in men and in women, reducing the likelihood of a specific occupational effect.

'Apart from these two diseases and the special case of childhood cancer, there was no evidence from these data that combustion emissions contributed to overall cancer mortality.'

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