Publications by authors named "Vladimír Tomášek"

2 Publications

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Settled iron-based road dust and its characteristics and possible association with detection in human tissues.

Environ Sci Pollut Res Int 2019 Jan 30;26(3):2950-2959. Epub 2018 Nov 30.

Center for Advanced Innovation Technologies, VŠB-Technical University of Ostrava,, 70800, Ostrava, Czech Republic.

Settled road dust was examined to detect the presence of non-airborne submicron and nano-sized iron-based particles and to characterize these particles. Samples were collected from a road surface near a busy road junction in the city of Ostrava, Czech Republic, once a month from March to October. The eight collected samples were subjected to a combination of experimental techniques including elemental analysis, Raman microspectroscopy, scanning electron microscopy (SEM) analysis, and magnetometry. The data thereby obtained confirmed the presence of non-agglomerated spherical nano-sized iron-based particles, with average sizes ranging from 2 down to 490 nm. There are several sources in road traffic which generate road dust particles, including exhaust and non-exhaust processes. Some of them (e.g., brake wear) produce iron as the dominant metallic element. Raman microspectroscopy revealed forms of iron (mainly as oxides, FeO, and mixtures of FeO and FeO). Moreover, FeO was also detected in samples of human tissues from the upper and lower respiratory tract. In view of the fact that no agglomeration of those particles was found by SEM, it is supposed that these particles may be easily resuspended and represent a risk to human health due to inhalation exposure, as proved by the detection of particles with similar morphology and phase composition in human tissues.
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http://dx.doi.org/10.1007/s11356-018-3841-xDOI Listing
January 2019

On airborne nano/micro-sized wear particles released from low-metallic automotive brakes.

Environ Pollut 2011 Apr 17;159(4):998-1006. Epub 2011 Jan 17.

Technical University Ostrava, Nanotechnology Center, Ostrava-Poruba, Czech Republic.

The paper addresses the wear particles released from commercially available "low-metallic" automotive brake pads subjected to brake dynamometer tests. Particle size distribution was measured in situ and the generated particles were collected. The collected fractions and the original bulk material were analyzed using several chemical and microscopic techniques. The experiments demonstrated that airborne wear particles with sizes between 10 nm and 20 μm were released into the air. The numbers of nanoparticles (< 100 nm) were by three orders of magnitude larger when compared to the microparticles. A significant release of nanoparticles was measured when the average temperature of the rotor reached 300°C, the combustion initiation temperature of organics present in brakes. In contrast to particle size distribution data, the microscopic analysis revealed the presence of nanoparticles, mostly in the form of agglomerates, in all captured fractions. The majority of elements present in the bulk material were also detected in the ultra-fine fraction of the wear particles.
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http://dx.doi.org/10.1016/j.envpol.2010.11.036DOI Listing
April 2011