Basel Area Research Articles

Single pollutant versus surrogate measure approaches: do single pollutant risk assessments underestimate the impact of air pollution on lung cancer risk?

Cancer 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 PM(10) as a surrogate of the total air pollution. The excess rate for lung cancer cases attributable to an increase of 10 microg/m3 in average PM(10) 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.

The Miocene Dislocations in the northern foreland of the Alps: Oblique subduction and its consequences (Basel area, Switzerland-Germany)

The Miocene Dislocations in the northern foreland of the Alps: Oblique subduction and its consequences (Basel area, Switzerland-Germany)

Erlebnisraum Augst-Pratteln im Kanton Basel-Landschaft

The geographical location of the canton of Basel in the trinational greater Basel area is highly favorable for many reasons. The benefits of the region, among them its excellent infrastructure, are to be used to create new future-oriented, value-creating jobs particularly in industrial and service companies. Already excellent housing facilities and the unspoiled landscape will be supplemented by an attractive leisure area drawing on the natural beauty of the region. On the Rhine plain between Augst and Pratteln potential exists for use of the location while ensuring that future development is combined and integrated in an exemplary way with the cultural heritage of the old Roman town of Augusta Raurica. New development at this nodal point is not only of importance to the two districts, but also to the future of the canton of Basel. Planning and development of this area is therefore a great challenge to regional planning professionals.

Plate interactions at the southern end of the Rhine graben

The southern end of the Rhine graben in the Basel area originated in the early Tertiary as an extensional structure. It is the site of a transfer zone that connected the Rhine graben with the Bresse–Rhone grabens. This transfer zone is located in an area into which a late Paleozic trough projects, which apparently was reactivated. From the beginning of Miocene to recent times, three distinct phases of slight compression were superimposed on the southern end of the Rhine graben. The first one in the Aquitanian–early Burdigalian is coeval with the development of the Helvetic nappes and the Insubric fault zone in the Alps. The second one in the Langhian–Tortonian interval occurred when the External Massifs and an important part of the Lombardic fold–thrust belt in the southern Alps developed, and the third, Pliocene to Recent one, is contemporaneous with the inactivation of this belt and its incorporation into the foredeep of the Northern Apennines. In the Aquitanian, the forebulge of the Alpine orogen is recognizable as a system of flexures that developed preferably on the margin of the late Paleozoic trough. The middle–late Miocene one gave rise to uplift of the Black Forest–Vosges domain and a river system flowing from this high to the south. In the Pliocene to Recent one Alpine rivers made their appearance, flowing first to the west into the Rhone system and then, as the Rhine, to the north. The Pliocene to Recent phase seems to be decoupled from the body of the Central and Southern Alps.

Temporal and spatial variation of the chemical composition of PM 10 at urban and rural sites in the Basel area, Switzerland

Particulate matter measurements of different size fractions (PM 4, PM 10, TSP) were performed in the Basel area (Switzerland) at seven urban sites throughout 1997 and at two urban and two rural sites during the following year (April 1998–May 1999). Based on a sample of filters which was chemically analyzed, we investigated the chemical composition of PM 10 both within the city of Basel and among urban and rural sites. The temporal and spatial variability of the chemical composition of PM 10 was evaluated taking into account additional data from meteorology and further air pollutants. The chemical analyses of PM 10 showed that carbonaceous substances (elemental carbon, organic matter) and inorganic substances of secondary origin such as sulfate, nitrate and ammonium were the most abundant component of PM 10 in the Basel area (approximately 60–70%). Difference in the PM 10 concentration between urban and rural sites was larger during the cold season than during the warm season. This was mainly due to the presence of an inversion layer between the city and the more elevated rural sites resulting in higher concentrations of nitrate, ammonium and organic matter in the city during the cold season. The higher PM 10 concentration on workdays compared to weekends was mostly a result of the temporal variation of the concentration of Ca, elemental carbon, Ti, Mn, and Fe, indicating that these compounds are for the most part caused by regional human activities. Although total PM 10 mass concentration was found to be in general uniformly distributed within the city of Basel, the chemical composition was more variable due to specific sources like road traffic and other anthropogenic emissions.

Spatial Variability of Different Fractions of Particulate Matter within an Urban Environment and between Urban and Rural Sites

ABSTRACT The 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.

Microzonation of the city of Basel

During the past centuries, the city of Basel has suffered damage caused by earthquakes. One extraordinary event described in historical documents is the strong earthquake which occurred in 1356. The 1356 event, one of the strongest earthquakes in northwest-Europe, was obviously much stronger than the low-magnitude earthquakes observed in the area during this century. Even though the present seismicity in the Basel area is low, strong earthquakes have to be expected due to the city's geographical location close to the northern boundary of the African-European convergence zone, at the southern end of the Rhinegraben. A crucial step towards preparedness for future events and mitigation of earthquake risk involves a microzonation study of the city. The study is carried out in three steps: (1) a detailed mapping of the geology and geotechnical properties of the area, (2) measurement, interpretation and modelling of ambient noise data, and (3) numerical modelling of expected ground motions during earthquakes. A qualitative microzonation of the centre of Basel is presented, and it is discussed by comparing it to the historically reported damage of the 1356 earthquake.

Evaluation of street facilities I, II and III in Basel

In June 1991 the city of Basel established the first low threshold centre (LTC) subsidized by the government after various private initiatives of "Live & Survive" aids. This low threshold facility which was supplemented in 1992 by two additional LTCs aimed at harm and risk reduction. The evaluation of LTCs was conducted by the institute for Social and Preventive Medicine of the University of Basel on behalf of the Federal Office of Health. Combining qualitative and quantitative research methods its structure was evaluated regarding the realization of its own objectives. The LTCs reached a great variety of drug addicts which were characterized by a remarkable heterogeneity. The majority of users were aged between 20 and 30, a quarter of them were female. Differences were found in housing conditions, subsistence and the degree of social integration. The facilities of the institutions were extensively used. In 1993 and 1994 a daily average of 250 to 300 visits was recorded in the injecting rooms only. the clientele were mainly residents of the Basel area. This lead to the conclusion that there was no attractive effect on more remote regions. As a consequence of the extensive use of the facilities a movement of the drug scene away from the street into the LTCs could be observed. In general, a stabilization or even an improvement of the physical condition of its users could be noticed. Another important feature was the improvement of the drug addicts' social integration. The main reason for this was the relationship between users and staff. Due to the shortage of personnel this promising base for further psychosocial work could not be adequately developed. The investigators not only concluded that there is a need for continuing maintenance of these facilities but also that additional efforts to improve the psychosocial services would be justified.