Traffic fumes 'impair children's lung development' » Health » 24dash.com

Traffic fumes from motorways can seriously impair the lung development of children, new research suggests.

A large-scale study in California found that 10-year-olds who lived within 500 metres of a motorway suffered a "substantial" loss of lung function by the age of 18.

The effect became less the further away a child lived from the road.

A similar impact was seen on both boys and girls, and there was little influence from social background, other pollution sources, or exposure to tobacco smoke.

Between the ages of 10 and 18, a period of rapid lung growth occurs. This can be assessed with tests which measure the amount of air a child can blow into a tube.

The scientists carried out annual lung function tests on 3,677 Californian children for eight years.

Those living at least 1,500 metres from a major road were used as a baseline. Compared with them, children living closer to motorways had less "puff" at the age of 18.

The researchers, led by Dr James Gauderman, from the University of Southern California in Los Angeles, reported in The Lancet medical journal: "Pronounced deficits in attained lung function at age 18 years were recorded for those living within 500 metres of a freeway."

For one test, their average performance was 3% lower than that of the baseline children. Another test showed an almost 7% reduction, but individual children had deficits of up to 10%.

The scientists said their findings pointed to diesel pollution as being a prime culprit.

Fine carbon particles, largely generated by diesel exhausts, had previously been shown to damage the lungs of children.

The "freeway effect" was seen in sub-groups of non-asthmatic and non-smoking teenagers, indicating that otherwise healthy children were being harmed.

The researchers wrote: "Since lung development is nearly complete by age 18 years, an individual with a deficit at this time will probably continue to have less than healthy lung function for the remainder of his or her life.

"In many urban areas, population growth is forcing the construction of housing tracts and schools near to busy roadways, with the result that many children live and attend school in close proximity to major sources of air pollution. In view of the magnitude of the reported effects and the importance of lung function as a determinant of adult morbidity (illness) and mortality, reduction of exposure to traffic-related air pollutants could lead to substantial public health benefits."

Commenting on the findings, Stephen Holgate, Medical Research Council Clinical Professor of Immunopharmacology at the University of Southampton, said: "This study in California once again draws attention to the toxic effects of traffic pollution on children's health.

"The finding that proximity of a child's residence from a busy road is linked to a marked reduction in lung function over an eight-year observation period builds on accumulating knowledge that the chemicals that are contained in the exhaust emissions of modern vehicles adversely effects the development of the lung through childhood. This is probably through their powerful oxidant effect on lung development in the first five-to-eight years of life.

"The implication of this study is that reduced lung function in childhood is a known risk factor for the development and worsening of asthma in children and the development of chronic obstructive pulmonary disease later in life, as well as reducing exercise tolerance and increasing the risk of serious lung infections in childhood."

Two Swedish experts, Dr Thomas Sandstrom and Dr Bert Brunekreef, from Umea University Hospital, pointed out in The Lancet that the influence of social factors was difficult to define and could not be completely ruled out.

But they added: "Gauderman and colleagues' paper does, combined with previous epidemiological studies on adverse health effects of traffic, focus on traffic emissions and risks of living close to major motorways. This finding leads to important questions for society about the structure of the transportation system, engines, fuels, combustion, and road dust in urban areas."

Dr John Moore-Gillon, president of the British Lung Foundation, said: "This study demonstrates the urgent need for more initiatives to reduce harmful emissions and improve the quality of the air we breathe. It also highlights the need for the Government to make lung disease a national priority.

"One in seven people in the UK suffers from some form of lung disease, but this is an area that is woefully under-resourced.

"Fifteen years ago the British Lung Foundation was among the first to highlight the fact that air pollution was a health and not simply an environmental issue. This latest study adds yet more weight to that view and highlights the need for further research into this vital field."

Copyrighty Press Association 2007