Description: Das Projekt "Characterisation of ultrafine particles (nano particles) for workplace protection (part 2)" wird vom Umweltbundesamt gefördert und von Universität Gießen, Medizinisches Zentrum für Ökologie, Institut und Poliklinik für Arbeits- und Sozialmedizin durchgeführt. To assess the increased biological effects of ultrafine particles 100 nm in diameter not only the free primary particles, but also the aggregates and agglomerates (A+A) of these primary particles, the stabilities of these A+A and the solubility of the primary particles have to be considered. According to environmental measuring programs workplace measurements of ultrafine aerosols are performed with instruments like the scanning mobility particle sizer (SMPS), that classify particles according to their diameter, but do not distinguish between massive particles and A+A which consist of ultrafine primary particles. Therefore, in comparison with measurements from SMPS, a method for the characterisation of ultrafine aerosols by transmission electron microscopy (TEM) has been developed. In addition to free primary particles and aggregates the number and the size of primary particles within the A+A can be registered. It is intended - to optimize this measuring method until it generates reproducible results for a duration of sampling of 1 hour and to apply it to relevant work places, - to characterise the stability of the A+A within aqueous suspension (i.e. to detect differences as they already have been observed between the A+A from diesel soot and from fume of metal inert gas welding) and - to analyse 6 of the ultrafine samples of the 19 granular dust samples that were tested on rats in the carcinogenicity study of Pott and Roller 2003. Free primary particles and aggregates are registered with the condensation particle counter. Simultaneously the ultrafine particles are sampled on nuclepore filters. TEM-analysis is performed at magnification x 40,000 in 10 to 25 TEM-fields using direct and indirect preparation. Information is obtained on - the morphology of the ultrafine particles - their composition of A+A - the number and the surface estimate of all primary particles - the size distribution of the A+A - distinction between liquid and solid particles - on the solubility of the ultrafine particles - on the stability of the A+A in aqueous suspension, when adequate dispersion agents are used. It is expected that the results on the concentrations of primary particles per mg or per A+A, which are generated for ultrafine aerosols in certain work places are useful to characterise the ultrafine aerosols and may be generalized for these work places.Dust volume, particle size and surface influence the response of granular biopersis-tent dust (GBS). From the reanalysis of the GBS administered in an intratracheal test using the transmission electron microscopy (TEM), tumour rates could be predicted sufficiently with a combination of volume and surface (R2 = 0,7) or volume and number of aggregates und agglomerates (A+A) or of primary particles (PT) per mg of the dust. Air measurements of the mass concentration and of the number concentration of the particles which were analysed by TEM were evaluated using these doses met-ric...
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Gießen ? Kanzerogenität ? Schadstoffgehalt ? Transmissionselektronenmikroskopie ? Ultrafeinstaub ? Biologische Wirkung ? Karzinogenese ? Morphologie ? Ökologie ? Staubgehalt ? Staub ? Dieselruß ? Prognose ? Aerosol ? Feststoff ? Partikelgrößenverteilung ? Ratte ? Rauch ? Filter ? Suspension ? Metall ? Partikelanzahl ? Flüssiger Stoff ? Persistenter Stoff ? Löslichkeit ? Messprogramm ? Messverfahren ? Dispersion ? Stoffbewertung ? Größenverteilung ? Studie ? Arbeitsschutz ? Tumor ? Vergleichsanalyse ? Messung ? Arbeitsplatz ? Luftschadstoff ? Kondensation ? Nanopartikel ? Partikel ? Schweißen ? Ballungsraum ? Sozialmedizin ? Staubanalyse ? Staubprobe ? Anzahlkonzentration ?
Region: Hessen
Bounding box: 9° .. 9° x 50.55° .. 50.55°
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 2004-07-01 - 2007-12-31
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