Determination of birch pollen allergens in different aerosol sizes

Allergens in fine particles may cause symptoms inallergic asthmatics. In order to assess the exposureof susceptible persons, a method to measure theallergen load in fine and coarse particles wasdeveloped. Aerosols are collected with a high-volume air samplerby multistage impaction. They are separated into fivesize classes, ranging from >10 μm to 10 μm). In smallersized fractions, the allergen load is often close tothe detection limit. When clearly detectable amountsof allergen are present, in the fine size fraction theallergen load shows only a weak correlation to thepollen counts and the allergen concentrations in thecoarse particle fractio

Validity of Annoyance Scores for Estimation of Long Term Air Pollution Exposure in Epidemiologic Studies: The Swiss Study on Air Pollution and Lung Diseases in Adults (SAPALDIA)

In air pollution epidemiology, estimates of long term exposure are often based on measurements made at one fixed site monitor per area. This may lead to exposure misclassification. The present paper validates a questionnaire-based indicator of ambient air pollution levels and its applicability to assess their within-area variability. Within the framework of the SAPALDIA (Swiss Study on Air Pollution and Lung Diseases in Adults) cross-sectional study (1991), 9,651 participants reported their level of annoyance caused by air pollution on an 11-point scale. This subjective measure was compared with annual mean concentrations of particulate matter less than 10 μm in diameter (PM10) and nitrogen dioxide. The impact of individual factors on reported scores was evaluated. Nitrogen dioxide concentrations at home outdoors (measured in 1993), smoking, workplace dust exposure, and respiratory symptoms were found to be predictors of individual annoyance scores. Regression of population mean annoyance scores against annual mean PM10 and nitrogen dioxide concentrations (measured in 1993 and 1991, respectively) across areas showed a linear relation and strong correlations (r > 0.85). Analysis within areas yielded consistent results. The observed associations between subjective and objective air pollution exposure estimates suggest that population mean scores, but not individual scores, may serve as a simple tool for grading air quality within areas. Reported annoyance due to air pollution should be considered an indicator for a complex environmental condition and thus might be used for evaluating the implementation of environmental policie

Field study of natural, mechanical and hybrid ventilation systems of 27 office buildings in the temperate zone country Switzerland

Analyses in this study focus on characteristics of three different clusters of ventilation for office buildings. These comprise natural, mechanical and hybrid ventilation. In a major project study, extensive data was collected from 27 office buildings. Besides physically measurable parameters, psycho-social-oriented surveys of building users and information about building-specific constructional or building technology were compiled. In a selection, results of indoor air quality (IAQ) and indoor environment quality (IEQ) were compared with current standards. Thom’s Discomfort Index (DI) suggested that, for all three clusters, populations feeling discomfort are to be expected during the summer months. Responses for certain aspects corresponding to IEQ and IAQ showed a remarkable seasonal divergence of satisfaction with air temperature for naturally ventilated buildings. The appearance of stagnant air is found to occur in its strongest form in naturally and hybrid ventilated buildings. Mechanically ventilated buildings were reported as having the lowest values for satisfaction with air humidity in winter. Each ventilation system comprises characteristic advantages and disadvantages. A tendency might favour, at least seasonally, mechanically or hybrid ventilated buildings. Differences between these two systems are not significant in this sample. The result raises the question of how much technical effort is actually necessary to provide satisfactory ventilation