Allergic diseases appear more often in children who grow up near busy roads. This is the result of a study of several thousand children, now published in the American Journal of Respiratory and Critical Care Medicine.
Under the direction of the Helmholtz Zentrum München, a German research group studied in a longitudinal study, over six years, whether associations are identifiable between the onset of atopic diseases and exposure to air pollutants originating from traffic. The scientists based their analysis, on the one hand, on the corresponding distance of the parental home to streets busy with traffic, and on the other hand, modeled values, for the respective residencial addresses of the children, of air pollution with fine dust, diesel soot and nitrogen dioxide.
The research team led by Dr. Joachim Heinrich of the Institute of Epidemiology of the Helmholtz Zentrum München compared, with this, the data of 3,061 six-year old children from Munich and its surroundings. From birth, their development has been tracked within the scope of the so-called GINI and LISA studies. The studies are led by Prof. Dr. H.-Erich Wichmann of the Helmholtz Zentrum München, and, among other things, are aimed at the study of behavioral and environmental risk factors for allergic diseases. In the current analysis, the results of medical research and regular parental interviews were considered. Moreover, the appearance of the specific IgE antibodies against common allergens in blood serum was tested in children at the age of 6.
The scientists were able to estimate individual values of exposure of children to fine dust and nitrogen dioxide, with the help of calculation models. It was shown that an escalation of asthmatic bronchitis and allergic sensitization to pollen and other common allergens occurred with increasing exposure to fine dust. Increased exposure to nitric oxide was linked to increases in eczema. Connections were noted, in particular, between the appearance of asthmatic bronchitis, hay fever, eczema and allergic sensitization, on the one hand, and residential environment, on the other: compared with their contemporaries living in more distant places, children who lived less than 50 m from a very busy main road were between 1 % and 50 % more likely to contract these diseases. Statistical analysis of the data showed a lower risk with increasing distances to the main roads.
Joachim Heinrich and his colleagues consider the results of their research to be clear evidence of the disadvantageous effects of air pollution from traffic on the causes of allergies and atopic diseases. In the past, epidemiological studies on this subject failed to supply a clear picture, although the effects of laboratory experiments and inhalation studies are well-known.