Quantification of local deposition patterns of inhaled radon decay products in human bronchial airway bifurcations.

Aerosol deposition studies with tracheobronchial casts and models have demonstrated that inhaled particles are preferentially deposited within transitional bifurcation zones, exhibiting hot spots in the vicinity of carinal ridges. The goal of the present study is to quantify the inhomogeneity of theoretically predicted deposition patterns by local deposition enhancement factors. First, inspiratory particle deposition patterns of unattached (1 nm), ultrafine (10 nm and 20 nm), and attached (100 nm and 200 nm) radon progeny within three-dimensional models of segmental bronchial airway bifurcations were simulated by a numerical fluid dynamics and particle trajectory model.

Multielemental characterization of several brands of fullerenes and fullerene precursors by instrumental neutron activation analysis.

The characterization of the purity of fullerenes is based on the concept of defining the percentage amount of the main component (e.g., C(60), C(70), etc.

Microprocessor controlled portable TLD system.

An up-to-date microprocessor controlled thermoluminescence dosemeter (TLD) system for environmental and space dose measurements has been developed. The earlier version of the portable TLD system, Pille, was successfully used on Soviet orbital stations as well as on the US Space Shuttle, and for environmental monitoring. The new portable TLD system, Pille'95, consists of a reader and TL bulb dosemeters, and each dosemeter is provided with an EEPROM chip for automatic identification.

Distribution of toxic and radiation components in air particulates.

The concentrations of several toxic heavy metals and volatile organic compounds (VOCs) in various types of Hungarian fly-ash fine particulates were investigated by means of instrumental neutron activation analysis, X-ray fluorescence analysis and gas chromatography, coupled with mass spectrometry. Within a power station, particulate samples were taken from the boiler zone (BO), from the electrostatic dust filter chamber (FI) and from the flue-gas at the top of the stack (ST). Enrichment rates of the toxic metals both in FI and ST particulate fractions related to the BO concentrations were calculated to enable the temperature dependence on the adsorption of the toxic components to be studied.

Long-term clearance of accidentally inhaled 60Co aerosols in humans.

Long-term body retention was measured in six workers who accidentally inhaled 60Co aerosols during manipulation with a high-activity 60Co source. Improved whole body counting and calibration techniques provided good conditions to follow body clearance over 5 y. A two-detector profile scanning arrangement was used to measure the activity distribution in vivo over the lung region.