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Publikation Spatial variability of different fractions of particulate matter within an urban environment and between urban and rural sites(Taylor & Francis, 2000) Röösli, Martin; Braun-Fährlander, Charlotte; Künzli, Nino; Bayer-Oglesby, Lucy; Theis, Gaston; Camenzind, Markus; Mathys, Patrick; Staehelin, JohannesThe spatial variability of different fractions of particulate matter (PM) was investigated in the city of Basel, Switzerland, based on measurements performed throughout 1997 with a mobile monitoring station at six sites and permanently recorded measurements from a fixed site. Additionally, PM10 measurements from the following year, which were concurrently recorded at two urban and two rural sites, were compared. Generally, the spatial variability of PM4, PM10, and total suspended particulates (TSP) within this Swiss urban environment (area = 36 km2) was rather limited. With the exception of one site in a street canyon next to a traffic light, traffic density had only a weak tendency to increase the levels of PM. Mean PM10 concentration at six sites with different traffic densities was in the range of less than ±10% of the mean urban PM10 level. However, comparing the mean PM levels on workdays to that on weekends indicated that the impact of human activities, including traffic, on ambient PM levels may be considerable. Differences in the daily PM10 concentrations between urban and more elevated rural sites were strongly influenced by the stability of the atmosphere. In summer, when no persistent surface inversions exist, differences between urban and rural sites were rather small. It can therefore be concluded that spatial variability of annual mean PM concentration between urban and rural sites in the Basel area may more likely be caused by varying altitude than by distance to the city center.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Single pollutant versus surrogate measure approaches: Do single pollutant risk assessments underestimate the impact of air pollution on lung cancer risk?(Lippincott Williams & Wilkins, 2003) Röösli, Martin; Künzli, Nino; Schindler, Christian; Theis, Gaston; Bayer-Oglesby, Lucy; Mathys, Patrick; Camenzind, Markus; Braun-Fahrländer, CharlotteCancer risk as a result of air pollution may be quantified by different approaches. We compared the sum of unit risk based effects of single pollutants with an epidemiology-based method by using PM10 as a surrogate of the total air pollution. The excess rate for lung cancer cases attributable to an increase of 10 μg/m3 in average PM10 exposure was estimated from available cohort studies. Applying the epidemiology-based risk method to the air pollution situation in the Basel area (Switzerland) resulted in 13.3 (95% CI = 6.9–19.8) excess lung cancer cases per 100,000 person years. This estimate was considerably higher than the unit risk-based estimate yielding 1.1 (range, 0.45–2.8) cancer cases per 100,000 person years. We discuss these discrepancies in light of inherent differences between approaches in toxicology and epidemiology.01A - Beitrag in wissenschaftlicher Zeitschrift