Heinrich Duhme

Increasing prevalence of hay fever and atopy among children in Leipzig, East Germany.

BACKGROUND Several surveys in children and adults have shown significantly lower prevalences of asthma and allergic diseases in eastern Europe than in western countries. In the former East Germany tremendous changes towards western lifestyle have occurred since unification. The aim of this survey was to investigate time trends in the prevalence of asthma and allergic diseases among children living in the eastern part of Germany. METHODS In 1995-96, 2334 (87.5%) schoolchildren in Leipzig participated in a cross-sectional study that used the same methods as a previous survey done shortly after the fall of communism in 1991-92. A self-administered questionnaire was distributed to the parents. Children underwent cold-air challenge and allergy skinprick tests to six common aeroallergens. FINDINGS The prevalence of hay fever (2.3% [34/1454] vs 5.1% [115/2252], p<0.0001) and atopic sensitisation (19.3% [252/1303] vs 26.7% [434/1624], p<0.0001) increased significantly between 1991-92 and 1995-96. However, there was no significant change in the prevalence of asthma, asthma-related symptoms, or bronchial hyper-responsiveness. INTERPRETATION These findings suggest important differences in the development of atopic disorders. The children were born about 3 years before unification and were therefore exposed to western living conditions only after the third birthday. Thus, factors operating very early in life may be particularly important for the acquisition of childhood asthma, whereas the development of atopic sensitisation and hay fever may also be affected by environmental factors occurring beyond infancy.

Urban traffic and pollutant exposure related to respiratory outcomes and atopy in a large sample of children

Conflicting results have been reported for the relationship between traffic exposure and inception of atopy. The effect of traffic on the prevalence of asthma and atopy at school age was investigated in a representative population. Random samples of schoolchildren (n=7,509, response rate 83.7%) were studied using the International Study of Asthma and Allergies in Childhood phaseII protocol with skinprick tests, measurements of specific immunoglobulin E and lung function. Traffic exposure was assessed via traffic counts and by an emission model which predicted soot, benzene and nitrogen dioxide (NO2). Traffic counts were associated with current asthma, wheeze and cough. In children with tobaccosmoke exposure, traffic volume was additionally associated with a positive skinprick test. Cough was associated with soot, benzene and NO2, current asthma with soot and benzene, and current wheeze with benzene and NO2. No pollutant was associated with allergic sensitisation. High vehicle traffic was associated with asthma, cough and wheeze, and in children additionally exposed to environmental tobacco smoke, with allergic sensitisation. However, effects of socioeconomic factors associated with living close to busy roads cannot be ruled out.

Are asthma and allergies in children and adolescents increasing? Results from ISAAC phase I and phase III surveys in Münster, Germany.

Objective: To assess time trends in symptoms of asthma, allergic rhinitis, and atopic eczema among children in Münster, Germany.

The association between self-reported symptoms of asthma and allergic rhinitis and self-reported traffic density on street of residence in adolescents

&NA; We examined the association between self‐reported symptoms of asthma and allergic rhinitis and self‐reported exposure to motor vehicle traffic in adolescents in Münster, Germany. A total of 3,703 German students age 12‐15 years completed a written and video questionnaire in 1994‐1995. We found positive associations between both wheezing and symptoms of allergic rhinitis during the past 12 months and self‐reported frequency of truck traffic. The sex‐ and age‐adjusted prevalence odds ratios and 95% confidence intervals (CI) for truck traffic, contrasting the categories “frequent” and “constant” against “never,” were, for wheezing obtained by written questionnaire: 1.53 (95% CI = 1.15‐2.05) and 2.15 (95% CI = 1.44‐3.21); for wheezing obtained by video questionnaire: 1.61 (95% CI = 1.26‐2.07) and 2.47 (95% CI = 1.74‐3.52); and for symptoms of allergic rhinitis: 1.71 (95% CI = 1.36‐2.15) and 1.96 (95% CI = 1.40‐2.76), respectively. We found a similar positive association with self‐reports on traffic noise. Putative confounding variables, including indicators of socioeconomic status, smoking, etc, did not alter these associations substantially. The results correspond closely with findings of a survey carried out in 1991 in Bochum, Germany. Our results support the hypothesis that exposure to motor vehicle traffic is related to symptoms of asthma and allergic rhinitis in children, but we cannot rule out misclassification due to self‐reports of traffic exposure. (Epidemiology 1996;7:578‐582)

Epidemiological analyses of the relationship between environmental pollution and asthma

Epidemiological studies performed on children and young adults indicate that the prevalence of asthma has increased over the past decades in a number of countries. Since genetic determinants alone are unlikely to explain these findings, environmental factors are expected to have an important impact on the prevalence of this disease. Environmental pollution, among many other factors, may play a role in the initiation and manifestation of asthma. However, there is little epidemiological evidence for a causal association between the classical major outdoor air pollutants, such as SO2 or particulate matter, and asthma. Evidence for an association between air pollution from motor vehicles and asthma is still controversial. Thus the indoor environment and other environmental determinants--including lifestyle factors--are likely to be more important as causes of asthma. Epidemiological studies are able to evaluate the effects of environmental factors on the health of human populations in their usual environments. In addition, they can measure associations between long-term environmental exposures and health outcomes. By using refined techniques for exposure and disease assessment, as well as time and cost-effective study designs, environmental epidemiology will increase the knowledge about the role of pollution as a possible cause of asthma.

The International Study of Asthma and Allergies in Childhood (ISAAC): objectives and methods; results from German ISAAC centres concerning traffic density and wheezing and allergic rhinitis.

The International Study of Asthma and Allergies in Childhood (ISAAC) was founded to maximize the value of epidemiological research into asthma and allergic disease by establishing a standardized methodology and facilitating international collaboration and comparison of data. The ISAAC design comprises three phases: Phase I uses validated core questionnaires designed to assess the prevalence and severity of asthma and allergic disease in defined populations; Phase II will investigate possible aetiological factors suggested by findings of Phase I and apply lung, blood and skin tests; Phase III will be a repetition of Phase I after 5 years to assess time trends in the prevalence and severity of wheezing, rhinitis and eczema in each ISAAC centre. In 1991 a survey on wheezing and allergic rhinitis in 2050 12-15 year old adolescents in Bochum showed a positive correlation between the prevalence of wheezing as well as allergic rhinitis and indicators of traffic density, controlling for putative confounders such as age, sex, passive smoking, active smoking, etc. In 1994-1995 an ISAAC Phase I survey conducted on adolescents in Münster, applying methodology similar to that in Bochum, found positive associations between surrogate measures of traffic density and 12 months prevalence of wheezing and lifetime prevalence of allergic rhinitis of a magnitude very close to that found in Bochum. The results from the two German cities provide support to the hypothesis that exposure to automobile emissions is related to wheezing and allergic rhinitis in children.

Self-reported traffic density and atopic disease in children. Results of the ISAAC Phase III survey in Muenster, Germany.

Positive associations between traffic exposure and atopic respiratory disorders in children have been described in several studies. We analyzed data related to self‐reported truck traffic density and several symptoms and diagnoses of asthma and hay fever (12‐month wheezing and rhinitis symptoms, diagnoses of asthma and hay fever) from the ISAAC Phase III survey in Muenster, Germany, using core written and video questionnaires. Data were collected from representative school‐based samples (n = 7345) of 6–7‐ and 13–14‐yr‐olds. In 13–14‐yr‐olds, according to exposure levels categorized into rare, frequent, and constant, with the ‘never’‐category used as reference, the sex‐adjusted prevalence ratios were 1.29 (95% CI = 1.08–1.53), 1.58 (1.29–1.94), and 1.57 (1.18–2.10) for wheeze in the past 12 months, and 1.20 (1.06–1.34), 1.35 (1.17–1.55), and 1.69 (1.42–2.0) for rhinitis symptoms in the past 12 months. Prevalence ratios in 6–7‐yr‐olds and results for a diagnosis of asthma were less consistent while no positive association was detected between hay fever and truck traffic in both age groups. When analyses were based on a more general traffic indicator (self‐reported traffic noise), no consistent associations were observed. Our data provide support for the hypothesis that residential exposure to truck traffic may adversely affect the health of children.