Auflistung nach Autor:in "Hill, Matthias"

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  • Vorschaubild nicht verfügbar
    Publikation
    Iron, manganese and copper emitted by cargo and passenger trains in Zürich (Switzerland). Size-segregated mass concentrations in ambient air
    (Elsevier, 02/2007) Bukowiecki, Nicolas; Gehrig, Robert; Hill, Matthias; Lienemann, Peter; Zwicky, Christoph N.; Buchmann, Brigitte; Weingartner, Ernest; Baltensperger, Urs [in: Atmospheric Environment]
    Particle emissions caused by railway traffic have hardly been investigated in the past, due to their obviously minor influence on air quality compared to automotive traffic. In this study, emissions related to particle abrasion from wheels and tracks were investigated next to a busy railway line in Zürich (Switzerland), where trains run nearly exclusively with electrical locomotives. Hourly size-segregated aerosol samples (0.1–1, 1–2.5 and 2.5–10 μm) were collected with a rotating drum impactor (RDI) and subsequently analyzed by synchrotron radiation X-ray fluorescence spectrometry (SR-XRF). In this way, hourly elemental mass concentrations were obtained for chromium, manganese, iron and copper, which are the elements most relevant for railway abrasion. Additionally, daily aerosol filters were collected at the same site as well as at a background site for subsequent analysis by gravimetry and wavelength dispersive XRF (WD-XRF). Railway related ambient air concentrations of iron and manganese were calculated for the coarse (2.5–10 μm) and fine (<2.5 μm) particle fraction by means of a Mn/Fe ratio investigation. The comparison to train type and frequency data showed that 75% and 60% of the iron and manganese mass concentrations related to cargo and passenger trains, respectively, were found in the coarse mode. The railway related iron mass concentration normalized by the train frequency ranges between 10 and 100 ng mˉ³ h iron in 10 m distance to the tracks, depending on train type. It is estimated that the personal exposure next to a busy railway line above ground is more than a magnitude lower than inside a subway station.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild nicht verfügbar
    Publikation
    Trace metals in ambient air.  Hourly size-segregated mass concentrations determined by synchrotron-XRF
    (American Chemical Society, 28.06.2005) Bukowiecki, Nicolas; Hill, Matthias; Gehrig, Robert; Zwicky, Christoph N.; Lienemann, Peter; Hegedüs, Ferenc; Falkenberg, Gerald; Weingartner, Ernest; Baltensperger, Urs [in: Environmental Science & Technology]
    Trace metals are ubiquitous in urban ambient air, with mass concentrations in the range of a few μg/m³ down to less than 100 pg/m³. To measure such low concentrations represents a challenge for chemical and physical analysis. In this study, ambient aerosol was collected in Zürich (Switzerland) in 1-h intervals and three size fractions (aerodynamic diameters 0.1−1 μm, 1−2.5 μm, and 2.5−10 μm), using a three-stage rotating drum impactor (RDI). The samples were analyzed by energy-dispersive Synchrotron radiation X-ray fluorescence spectrometry (SR-XRF) to obtain size-segregated hourly elemental aerosol mass concentrations for Cr, Mn, Fe, Cu, Zn, Br, and Pb, along with S, Cl, and Ca under the selected experimental conditions. The high sensitivity of SR-XRF allowed for detection limits of <50 pg/m³ for most of the above elements, with a net analysis time of only 15 s per sample. The data obtained with this technique illustrate that there is a considerable gain of relevant information when time resolution for measurements is increased from 1 day to 1 h. The individual size fractions of a specific element may show significantly different short-term patterns.
    01A - Beitrag in wissenschaftlicher Zeitschrift