|
|
Determination of permeability of ulra-fine lead oxide aerosols through military filters
Kellnerova, E. ; Večeřa, Zbyněk ; Kellner, J. ; Zeman, T. ; Hylak, Č.
Military filters introduced in the Army of the Czech Republic are most commonly used when working with combat equipment and weapons and in manoeuvring activities in the terrain with the use of explosives or chemical warfare agents. During such activities, a large number of pollutants in the form of nanoparticles are released. Nanoparticles, irrespective of their chemical composition, are classified as carcinogenic to humans and therefore it is necessary to eliminate them from the air. Military filters, especially the combined ones, which contain a filtration as well as sorption component, are most widely used and are designed for the widest range of pollutants. However, the current methodology to evaluate the effectiveness of military filters does not fix a duty to monitor the ability of the filters to capture relevant pollutants across the whole range of sizes. The paper evaluates the efficiency of selected types of military filters using the methodology and instrumentation introduced in the accredited laboratories of the Institute of Analytical Chemistry of the Academy of Sciences of the Czech Republic. The testing has been carried out simultaneously with two concentrations of ultra-fine aerosols containing lead oxide nanoparticles ranging in size from 7.6 nm to 299.6 nm. It is an aerosol, the physicochemical and toxicological properties of which are known. During the work the basic parameters of permeability of aerosols tested by filters have been evaluated, especially: size and number of particles in front of and behind the filter, the efficiency and penetration of nanoparticles by the filter.
|
|
|
Influence of inhaled manganese oxides nanoparticles on mass of internal organs in mice
Zeman, T. ; Dočekal, Bohumil ; Mikuška, Pavel ; Buchtová, Marcela ; Míšek, Ivan ; Šerý, Omar ; Večeřa, Zbyněk
Results of the statistical analysis of a long-term inhalation experiment on laboratory mice are presented. During 17 weeks of the experiment, the experimental group was exposed to inhaled manganese oxides nanoparticles. Manganese oxides (MnO center dot Mn2O3) nanoparticles (MnONPs) were synthesized continuously via aerosol route in a hot wall tube flow reactor using a thermal decomposition of metal organic precursor manganese(II) acetylacetonate in the flow tube reactor (in vertical position) at temperature 750 degrees C in the presence of 30 vol% of oxygen. The concentration of produced MnONPs at the reactor output was in the range 1-3 x 10(7) particles/cm(3) and the size of generated nanoparticles MnO center dot Mn2O3 was in the range 7-50 nm. Before entering the inhalation chamber, MnONPs in the mixture of N-2, O-2 and air (at total flow rate of 3 L/min) were further diluted using filtrated humidified air (20 L/min) at temperature 21 degrees C resulting in the MnONPs concentration 2 x 10(6) particles/cm(3). At regular time intervals the mass of selected internal organs of mice from both experimental and control group was assessed. It has been proven that inhaled nanoparticles are able to influence the mass of internal organs of mice. Statistically significantly lower mass of kidneys, liver and spleen and higher mass of pancreas have been found in the experimental group compared to the control group.
|
|
| |
|
|
Influence of inhaled manganese oxides nanoparticles on mass of internal organs in mice
Zeman, T. ; Dočekal, Bohumil ; Mikuška, Pavel ; Buchtová, Marcela ; Míšek, Ivan ; Šerý, Omar ; Večeřa, Zbyněk
Results of the statistical analysis of a long-term inhalation experiment on laboratory mice are presented. During 17 weeks of the experiment, the experimental group was exposed to inhaled manganese oxides nanoparticles. Manganese oxides (MnO.Mn2O3) nanoparticles (MnONPs) were synthesized continuously via aerosol route in a hot wall tube flow reactor using a thermal decomposition of metal organic precursor manganese(II)acetylacetonate in the flow tube reactor (in vertical position) at temperature 750 °C in the presence of 30 vol% of oxygen. The concentration of produced MnONPs at the reactor output was in the range 1-3 × 107 particles/cm3 and the size of generated nanoparticles MnO.Mn2O3 was in the range 7-50 nm. Before entering the inhalation chamber, MnONPs in the mixture of N2, O2 and air (at total flow rate of 3 L/min) were further diluted using filtrated humidified air (20 L/min) at temperature 21 °C resulting in the MnONPs concentration 2 × 106 particles/cm3. At regular time intervals the mass of selected internal organs of mice from both experimental and control group was assessed. It has been proven that inhaled nanoparticles are able to influence the mass of internal organs of mice. Statistically significantly lower mass of kidneys, liver and spleen and higher mass of pancreas have been found in the experimental group compared to the control group.
|
|
|
The first experiencies with new exposure system for the whole body inhalation experiments with small animals
Večeřa, Zbyněk ; Mikuška, Pavel ; Moravec, Pavel ; Smolík, Jiří
The first experiences with an inhalation chamber constructed for long-term exposure studies of small animals to nanoparticles under strictly controlled experimental conditions. The inhalation chamber was build from a glass and stainless steel and allows possible long-term inhalation procedures with up to four discrete groups of mice or of rats population under controlled illumination, temperature, relative humidity and pressure. Doses up to 1 x 10(6) particles/cm(3) and size (10-60 nm) of nano-sized particles were synthesized via aerosol route in a hot wall tube flow reactor using thermal decomposition of metal organic precursors. The function of exposure system for whole body inhalation experiments was studied under real conditions in period from May to September 2012. No animals were used within this trial experiment.
|
|
| |
|
|
Synthesis of Lead and Lead Oxide Nanoparticles for Inhalation Experiments
Moravec, Pavel ; Smolík, Jiří ; Ondráček, Jakub ; Vodička, Petr ; Fajgar, Radek
From the three tested methods of NP's generation the evaporation/condensation of metallic Pb seems to be the most suitable for long lasting inhalation experiments due to its simplicity, unambiguous mechanism of NP′s formation and well defined composition. Nevertheless, NP′s can change their composition, at least on the surface layer, during the time-lag between their formation and inhalation. Thermal decomposition of PbTHD2 can produce sufficiently high concentration of NP′s but there is some uncertainty about their composition due to presence of OC in NP′s. Oxidation of PbTHD2 produces carbon free NP′s, but the number concentration of NP′s is somewhat low.
Plný tet: SKMBT_C22013101814595 -  PDF
Plný text: content.csg - PDF
|
|
|
Generation of Pb/PbOx Nanoparticles for Inhalation Experiments
Moravec, Pavel ; Smolík, Jiří ; Ondráček, Jakub ; Vodička, Petr ; Fajgar, Radek
Health aspects of nanoparticles (NP′s) on living beings are considered to be important. However, the real data of the impact of NP′s inhalation are rather rare. A study of allocation of MnOx nanoparticles in organs of laboratory animals in inhalation chamber was presented by Večeřa and Mikuška (2012). For these experiments a source of continual generation of nanoparticles in duration of days or even weeks and in appropriate concentration is necessary. In this work a study of continual generation of Pb/PbOx nanoparticles in hot wall tube reactor are presented.
Plný tet: SKMBT_C22013091912130 - PDF
Plný text: content.csg - PDF
|
|
|
Inhalace nanočástic MnxOy
Mikuška, Pavel ; Večeřa, Zbyněk ; Dočekal, Bohumil
Příspěvek se zabývá inhalací nanočástic MnxOy malými experimentálními zvířaty a studiem alokace Mn v orgánech exponovaných myší. Obsah Mn v orgánech exponovaných myší byl porovnán s obsahem Mn v orgánech kontrolního vzorku myší, které inhalaci nanočásticemi MnxOy nebyly podrobeny.
|
|
|
Unique exposure system for the whole body inhalation experiments with small animals
Večeřa, Zbyněk ; Mikuška, Pavel ; Moravec, Pavel ; Smolík, Jiří
The especially inhalation chamber is constructed for chronic exposure studies of small animals to nanoparticles under strictly controlled conditions in frame of project „Study of transport of inhalated nano-sized particles (Pb, Cd) and their allocation in organs“. The inhalation chamber builds from a glass and stainless steel and makes possible long-term inhalation procedures (up to 60 days, 24 hours/day) with up to four discrete groups of mice population (up to 60 individuals each) or of rats population (up to 20 individuals each) under controlled illumination, temperature, relative humidity, doses (0.5 x 106 - 5 x 106 particles/cm3) and size (10-60 nm) of nano-sized particles which are synthesized via aerosol route in a hot wall tube flow reactor using metal organic precursors.
|
host ::
RSS.