Publications by authors named "T Koskentalo"

Background And Purpose: Daily variation in outdoor concentrations of inhalable particles (PM(10) <10 microm in diameter) has been associated with fatal and nonfatal stroke. Toxicological and epidemiological studies suggest that smaller, combustion-related particles are especially harmful. We therefore evaluated the effects of several particle measures including, for the first time to our knowledge, ultrafine particles (<0.

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The performance of a modified Harvard high-volume cascade impactor (HVCI) was evaluated in six field campaigns with size-segregated particulate samplings for chemical and toxicological characterization. The 7-week sampling campaigns in 2002-2003 in Duisburg (autumn), Prague (winter), Amsterdam (winter), Helsinki (spring), Barcelona (spring), and Athens (summer) were selected to represent contrasting urban environments and seasons of public health interest due to high particulate concentrations or previous findings in epidemiological studies. Particulate samples were collected in parallel with the HVCI (PM(10-2.

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In order to characterize and compare the chemical composition of diesel particulate matter and ambient air samples collected on filters, different extraction procedures were tested and their extraction efficiencies and recoveries determined. This study is an evaluation of extraction methods using the standard 16 EPA PAHs with HPLC fluorescence analysis. Including LC analysis also GC and MS methods for the determination of PAHs can be used.

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Special episodes of long-range transported particulate (PM) air pollution were investigated in a one-month field campaign at an urban background site in Helsinki, Finland. A total of nine size-segregated PM samplings of 3- or 4-day duration were made between August 23 and September 23, 2002. During this warm and unusually dry period there were two (labelled P2 and P5) sampling periods when the PM2.

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Objectives: The chemical composition and toxicity of wintertime urban-air particulate matter with an aerodynamic diameter of <10 microm (PM10), derived mostly from long-range transport and local combustion sources, were compared with those of springtime PM10 derived mostly from the resuspension of road dust.

Methods: Water-soluble ions and elements and polycyclic aromatic hydrocarbons (PAH) were analyzed from seasonally pooled PM10 samples collected at a busy traffic site in Helsinki in 1999. These PM10 samples were also tested for cytotoxicity [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide test] and the production of proinflammatory cytokines [tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6)] and nitric oxide (NO) in the mouse macrophage cell line RAW 264.

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