Bálint Alföldy

Particulate matter analysis at elementary schools in Curitiba, Brazil.

The particulate matter indoors and outdoors of the classrooms at two schools in Curitiba, Brazil, was characterised in order to assess the indoor air quality. Information concerning the bulk composition was provided by energy-dispersive x-ray fluorescence (EDXRF). From the calculated indoor/outdoor ratios and the enrichment factors it was observed that S-, Cl- and Zn-rich particles are of concern in the indoor environment. In the present research, the chemical compositions of individual particles were quantitatively elucidated, including low-Z components like C, N and O, as well as higher-Z elements, using automated electron probe microanalysis low Z EPMA. Samples were further analysed for chemical and morphological aspects, determining the particle size distribution and classifying them according to elemental composition associations. Five classes were identified based on major elemental concentrations: aluminosilicate, soot, organic, calcium carbonate and iron-rich particles. The majority of the respirable particulate matter found inside of the classroom was composed of soot, biogenic and aluminosilicate particles. In view of the chemical composition and size distribution of the aerosol particles, local deposition efficiencies in the human respiratory system were calculated revealing the deposition of soot at alveolar level. The results showed that on average 42% of coarse particles are deposited at the extrathoracic level, whereas 24% are deposited at the pulmonary region. The fine fraction showed a deposition rate of approximately 18% for both deposition levels.

Aerosol Drug Delivery Optimization by Computational Methods for the Characterization of Total and Regional Deposition of Therapeutic Aerosols in the Respiratory System

The intake of medicines in form of aerosols is becoming increasingly popular, especially in the treatment of different lung diseases and allergies. In addition, there is a great interest to utilize the inhalation pathway for systemic therapy. Hence, determination of the required local distribution of inhaled therapeutic aerosols within the respiratory system is a key issue of modern aerosol drug design. In general, deposition characteristics of inhaled particles depend on the properties of the aerosols, the breathing mode and the geometry of the airways. All three parameters must be analyzed for the optimal design of therapeutic aerosols. A recommended way of drug inhalation may differ for various illnesses and patients. There are two different modeling directions for the description of deposition characteristics of inhaled drugs in the respiratory system. One way is the application of lung deposition models for the determination of total, regional and airway generation-specific deposition, and the other way is the usage of computational fluid dynamics techniques for the characterization of local deposition patterns, which, at present, cannot be applied to the whole respiratory system. This computational fluid dynamics approaches will be analyzed in another study. This work describes the general background of aerosol drug delivery optimization, summarizes previous important studies in the field, and provides a comprehensive discussion about numerical lung modeling and the salient features of the newest models and techniques. In the last part, the stochastic lung deposition model is applied to determine the optimal particle size and breathing technique for bronchial and pulmonary drug delivery.

Determination of trace elements in lithium niobate crystals by solid sampling and solution-based spectrometry methods

Solid sampling (SS) graphite furnace atomic absorption spectrometry (GFAAS) and solution-based (SB) methods of GFAAS, flame atomic absorption spectrometry (FAAS), inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS) were elaborated and/or optimized for the determination of Cr, Fe and Mn trace elements used as dopants in lithium niobate optical crystals. The calibration of the SS-GFAAS analysis was possible with the application of the three-point-estimation standard addition method, while the SB methods were mostly calibrated against matrix-matched and/or acidic standards. Spectral and non-spectral interferences were studied in SB-GFAAS after digestion of the samples. The SS-GFAAS method required the use of less sensitive spectral lines of the analytes and a higher internal furnace gas (Ar) flow rate to decrease the sensitivity for crystal samples of higher (doped) analyte content. The chemical forms of the matrix produced at various stages of the graphite furnace heating cycle, dispensed either as a solid sample or a solution (after digestion), were studied by means of the X-ray near-edge absorption structure (XANES). These results revealed that the solid matrix vaporized/deposited in the graphite furnace is mostly present in the metallic form, while the dry residue from the solution form mostly vaporized/deposited as the oxide of niobium.

A measurement based analysis of the spatial distribution, temporal variation and chemical composition of particulate matter in Munich and Augsburg

The objective of the studies presented in this paper is to present an analysis of spatial distribution and temporal variation of particulate matter in Munich and Augsburg, Germany, and to identify and discuss the factors determining the aerosol pollution in both areas. Surface-based in-situ and remote sensing measurements of particle mass and particle size distribution have been performed in, around, and above the two cities. Two measurement campaigns were conducted in Munich, one in late spring and one in winter 2003. Another campaign has been on-going in Augsburg since 2004. Spatial and temporal variations are analyzed from this data (PM 10 , PM 2.5 and PM 1 ). There are higher particle mass concentrations at the urban site than at the surrounding rural sites, especially in winter. No significant difference in the major ionic composition of the particles between the urban and the rural site was detected. This is considered to be related to the spatial distribution of secondary inorganic aerosol that is more homogeneous than aerosol resulting from other sources like traffic or urban releases in general. During the measurement campaigns mixing layer heights were determined continuously by remote sensing (SODAR, ceilometer, RASS). Significant dependence of particle size distribution and particle mass concentration on mixing layer height was found. This finding paves the way to new applications of satellite remote sensing products.

Size Distribution, Pulmonary Deposition and Chemical Composition of Hungarian Biosoluble Glass Fibers

Compared to spherical particles, inhaled fibers may cause enhanced adverse health effects because of their specific shape, thus acting as so-called physical carcinogens. The chemical composition of fibers plays a determining role on the durability and hence may play a potential role in related health effects due to their toxic components. The physical properties, that is, length, diameter, and size distribution, and the chemical composition of fiberglass materials sampled at a Hungarian glass wool factory were investigated. The morphology of the particles was studied by optical microscopy and scanning electron microscopy (SEM), while for the chemical analysis instrumental neutron activation analysis (INAA) and SEM combined with energy-dispersive x-ray analysis (EDX) were used. Deposition fractions of the fibers in different regions of the lung and in the whole human respiratory system were computed by a stochastic lung deposition model for different flow rates and equivalent diameters, using experimentally determined size distributions.

Budapest airport air quality long-term studies by remote sensing with DOAS and FTIR with focus upon runway emissions

Airport air quality is influenced by traffic mainly. Near runway the aircrafts are the main source. The quantification of these emission sources requires remote sensing methods because the airport operations should not be disturbed. DOAS is used in open-path mode to detect continuously NO2 cross the runway during nearly one year. Those runway emission studies were performed for the first time. During the measurement campaign these findings were compared with corresponding aircraft taxiway emission measurements. The concentration measurements of CO2 which are necessary to calculate emission indices are provided by open-path FTIR spectrometry. Aircraft emission indices of CO, NO and NO2 could be determined at taxiway only. Open questions and required further developments will be discussed.