[Effect of climatic changes on the phenology of plants and the presence of pollen in the air in Switzerland]. / Influence du changement climatique sur la phénologie des plantes et la présence de pollens dans l'air en Suisse.

The phenologic observations carried out in Switzerland since 1951 show a clear tendency to the earlier appearance of the spring phases of development of the vegetation during last decades. As these phases are strongly influenced by the temperature, these results reinforce the hypothesis according to which the climatic reheating in progress strongly influences the development of the vegetation. The flowering and the release of the pollen of the plants allergens are significant phenologic phases for human health. Modifications in their dates of manifestation lead to a displacement of the periods of allergic risk. The analysis of the aerobiologic data of the Swiss stations over one duration of more than 20 years showed that the species which flower in winter and in spring were subject to the influence of the soft winters of the years 1990 to 2000. In certain areas the pollen of birch, for example, is nowadays waited on average 3 weeks earlier than 20 years ago, whereas the pollen of ash appears with one month in advance. The phenologic and aeropalynologic studies thus prove sensitive witnesses of the climatic change in progress. This last intervenes like an indirect but significant component of human health, in particular when the field of the allergies is considered.

Phytophenological trends in Switzerland.

Nation-wide phenological observations have been made in Switzerland since 1951. In addition to these observation programmes, there are two very long phenological series in Switzerland: leaf bud burst of horse-chestnut trees has been observed in Geneva since 1808 and full flowering of cherry trees in Liestal since 1894. In addition to the presentation of these two long phenological series, trends for 896 phenological time series have been calculated with national data from 1951 to 1998. The earlier bud burst of horse-chestnut trees in Geneva can be attributed mainly to the city effect (warmth island). This phenomenon was not observed with the cherry tree flowering in Liestal. A clear trend towards earlier appearance dates in spring and a weak tendency towards later appearance dates in autumn could be shown with data from the national observation network. It must be noted that different phenophases and plant species react differently to various environmental influences.

[Swiss Study on Air Pollution and Lung Diseases in Adults (SAPALDIA)]. / Etude suisse sur la pollution de l'air et les maladies respiratoires chez l'adulte (SAPALDIA). Swiss Study on Air Pollution and Lung Diseases in Adults.

Long-term health effects of moderate ambient air pollution are rarely investigated. In Switzerland, no large-scale study has addressed this issue so far. Important results of the Swiss Study on Air Pollution and Lung Disease in Adults (SAPALDIA) are presented. During the period 1991-1993, SAPALDIA investigated a random population sample (18-60 years) in eight Swiss areas with different environmental characteristics (Aarau, Basel, Davos, Geneva, Lugano, Montana, Payerne, Wald). In total, 9651 adults (60%) participated in the cross-sectional investigation (part 1, 1991), consisting of the following standardized procedures: questionnaire (interview), forced expiratory lung function test, bronchial challenge with methacholine, atopy assessment (Phadiatop, unspecific total IgE), allergy skin tests, and endexpiratory CO-measurements. Subjects with a history of respiratory symptoms, increased bronchial reactivity, reduced lung function (FEV1/FVC < 80% predicted) and 150 healthy never-smokers were included in the subsequent diary study (part 2; n = 3281, 1992/93). Peak flow (morning and evening), symptoms, medication, personal activity and visits to the doctor were monitored. Across regions, annual mean values ranged from 9 to 52 mg/m3 (NO2) and 10 to 33 mg/m3 (PM10) respectively. Air pollution had effects on prevalence of dyspnea (+41% per 10 mg/m3 increment of the annual mean PM10, 95% CI 20-65%), on symptoms of chronic bronchitis (+31%, 10-55%), on FVC (-3.1%; -3.7 to -2.6%), and FEV1 (-1.1%; -1.7% to -0.5%), on the incidence of respiratory symptoms and the length of symptomfree intervals (11% change per 10 mg/m3 PM10), but not on the prevalence of asthma. Environmental tobacco smoke (ETS) showed impact on wheezing (OR 1.94; 1.39-2.70), asthma (1.39; 1.04-1.86), bronchitis (1.60; 1.24-2.08) and chronic bronchitis (1.50; 1.11-2.02). Health effects of moderate air pollution were confirmed in Switzerland. Although for the individual the relative risks are small, the public health impact may be considerable. An ongoing follow-up will investigate the mortality profile of the SAPALDIA cohort.

SAPALDIA: methods and participation in the cross-sectional part of the Swiss Study on Air Pollution and Lung Diseases in Adults.

SAPALDIA--the Swiss Study on Air Pollution and Lung Diseases in Adults--focuses on the long term health effects of low to moderate levels of air pollutants as typically seen in different parts of Switzerland. The aim of the SAPALDIA cross-sectional study carried out in 1991 was to determine the prevalence of bronchial asthma, chronic bronchitis and allergic conditions in the adult population of Switzerland and to identify and to determine the respective importance of potentially influencing factors. These could be both personal (smoking habits, allergy status, family history, occupation) and environmental (outdoor and indoor pollution, aeroallergens, climate). A further aim of the cross-sectional study consisted in the identification of individuals susceptible to present symptoms during a two year observation period and to be included in the SAPALDIA follow-up study. This technical report represents the methodological documentation for the cross-sectional study of SAPALDIA. The instruments and the methods of standardisation are presented and discussed. The medical examination consisted of a computerised interview using a standardised questionnaire, the taking of a blood sample for serological tests, allergy skin testing, the measurement of end expiratory CO and body height, and pulmonary function testing followed by methacholine challenge testing or bronchodilatation testing. The pattern of participation and the 9651 participants of the study, representing 59.3% of the sample, are described. Based on information on non-participants gained by telephone interviews and mailed short questionnaires, possible selection biases are quantified and discussed.

[Phenology, an indicator for environmental changes]. / Phänologie, ein Indikator für Umweltveränderungen.

After a short introduction to phenology, the complex environmental factors influencing vegetation are explained and discussed. Three special phenological series are presented and analyzed (flowering time of summer lime trees at Liestal, 1951 to 1989, and of the cherry trees at Liestal, 1894 to 1990, and the time of appearance for leaves of chestnut trees at Geneva, 1808 to 1991). The temporal progress of the evolution of the vegetation between 1951 to 1990 in Switzerland shows that the "early", "normal" and "late" years succeed one another irregularly. For the processing of phenological data, the fact that growth and development of a plant are determined by numerous and complex environmental factors has also to be considered.