When children have breathing problems

Increasing numbers of children around the world are suffering from respiratory problems – coughing, wheezing and asthma attacks. Although the key external causes of these diseases were identified a long time ago (traffic and industrial air pollution), it had not previously been possible to distinguish clearly between these two factors so as to have a targeted impact on them. Researchers at the Helmholtz Centre for Environmental Research (UFZ) and the University of Leipzig carried out research in this area together with colleagues from the University of La Plata and can now confirm that air pollution caused by industry has even more grave effects than vehicle exhaust fumes.

The recently completed study on 'Combined effects of airborne pollutants as risk factors for environmental diseases' was conducted as part of a long-standing collaborative venture, supported by the international office of the German Federal Ministry of Education and Research, between the Helmholtz Centre for Environmental Research (UFZ), the University of Leipzig and the University of La Plata in Argentina. The results have been published in several internationally-respected journals, including the Journal of Allergy and Clinical Immunology and Toxicology.

The UFZ researchers, who work in the Division of Health Research in Leipzig, concentrated on three courses of analysis: "Firstly," says Leipzig-based biologist Andrea Müller, "we used measurement techniques to draw accurate conclusions about the actual pollution of breathing air. We filtered out particulate matter of different grain sizes, polycyclic aromatic compounds, such as benzo(a)pyrene, that adhere to these particles, and volatile organic compounds, such as benzene and hexane. Secondly, we tested their toxic and mutagenic properties. We selected four comparative source regions: a residential area in the immediate vicinity of Argentina's largest oil refinery, an area with heavy traffic in the centre of La Plata, a suburban area and a rural area."

The children whose health formed the basis of the third course of analysis were selected from the same four areas. Around 1200 girls and boys aged between six and twelve were involved in the research that lasted about two years. With a parent-completed questionnaire data about the children's health symptoms were asked, such as coughs, wheezing, pneumonia and asthma attacks. Some of the children from each of the four regions were also invited to take a lung function test by the local paediatricians involved in the project. During the test the children were asked to blow into measuring devices – first hard and then slowly. This provided a measurement of the extent to which their bronchial tubes were constricted and therefore limited in function.

When all these measurements were concluded in La Plata at the end of 2006, thousands of pieces of data had to be compiled and correlated. It is possible to draw some notable conclusions from the columns of numbers and tables. They show, for instance, that the different respiratory disease symptoms in the industrial areas included in the study affect between a quarter and a third of all children. In the suburbs and in the countryside only half as many children tend to be affected and even in the city centre only around one or two per cent more children are affected than in the relatively unpolluted areas. The lung function of children from the industrial area was also significantly impaired. The researchers had not been expecting to find such a marked contrast.