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Characterisation of road dust
Abstracts
699
a background monitoring station (Bily Kriz, 49” 30’ N, 18” 23’ E, 940 m.a.s.1.) in the Czech Republic. The purpose of the study is to characterize the influence of various sources in Central Europe on the ambient aerosol. A total of 299 24 h samples were collected during the monitoring campaign and analysed with PIXE (particle induced X-ray emission). The PIXE analysis quantified 18 elements (Si, S, Cl, K, Ca, Ti, V, Mn, Fe, Ni, Cu, Zn, Ga, As, Se, Br, Sr and Pb) in a majority of the samples. An absolute multivariate source/receptor model (absolute principal component analysis; APCA) indicated that there are six relevant source types affecting the Bily Kriz sampling site. These are (1) a combination of ferrous and non-ferrous smelters (K. Mn, Fe, Cu, Zn, Ga and Pb) and traffic (Br and Pb), (2) soil dust (Si, Ca, Ti, Fe, Sr), (3) oil combustion (V, Ni), (4) coal combustion (As, Se), (5) secondary sulphate (S) and (6) sea spray (Cl). The station is believed to be affected by the heavily industrialized region around Katowice and Krakow in Poland, the Czech town of Ostrava, the coal-burning Erzgebirge region in the Czech Republic, the Donetsk region in Ukraine, the Ruhr area in Germany and the Benelux countries. A more detailed analysis of the origin of the various pollutants will be performed by studying three-dimensional back trajectories.
CHARACTERISATION L. Hdkan Environmental
Physics,
Department
OF ROAD DUST Johansson
of Physics,
CTH S-412 96 Giiteborg,
Sweden
Abstract-During dry periods in the winter, road dust particles can dominate over exhaust particles in areas where studded tires are common. An aerosol sampling was made during February and March 1993 near a busy street in Goteborg. The impactor used (virtual dichotomous Sierra-Andersen) fractionates particles into two size intervals, d, c 2.5 pm and 2.5 < d, -c 10 pm. The samples were weighed and analysed for elemental composition with EDXRF technique. Factor analysis was made on the concentrations of the elements to investigate possible sources for the particles. Four factors were clearly identified and are attributed to the following sources: engine emissions from the traffic, road dust, sea salt and long distance transport. Both sea salt and road dust contributed to the variance of the coarse particle mass, but if occasions with westerly winds were excluded the sea salt factor disappears. Regression analysis was made on the coarse particle mass and on elements clearly identified with road dust (occasions with westerly winds were excluded) to give the concentration of these elements in road dust. Major components were Cl (23%), Fe (2.8%), Ca (1.2%) and K (0.75%). Trace elements were Ti (16OOppm), Zn (880 ppm), Pb (670 ppm), Mn (440 ppm), V (160 ppm), Cr (100 ppm) and Ni (50 ppm).
RADON AND AEROSOLS A. Reineking Isotopenlabor
fur biologische
und medizinische
Forschung,
Burckhardtweg
2, D-37077
Giittingen,
Germany
Abstract-The inhalation of the short-lived radon and thoron decay products in the domestic environment yields the largest amount of natural radiation exposure of the human public. From risk calculations it can be estimated that about 5-10% of all lung cancers are due to the inhalation of these natural airborne radionuchdes. The deposition of the “unattached” and aerosol-associated decay products in the human lung depends primarily on the particle size. Besides the airborne activity concentrations and biological parameters, the size characteristics of these decay products and the magnitude of the “unattached” activities are two of the most important parameters in all models for dose calculations. The size characteristics are also essential for understanding and describing the behaviour of the airborne activity in indoor and outdoor environments. The behaviour and the size distribution of the radon decay products in houses are determined by the following processes: (a) (b) (c) (d)
formation of the “unattached” decay products, cluster growth and neutrahsation, attachment to the aerosol particle and formation of a radioactive aerosol, desorption of the particle surfaces, deposition or plate-out on surfaces in a room.
After a brief description of these fundamental processes, measurement techniques for size analysis of short-lived radon/thoron decay products and actual results of aerosol sizes in homes and the outdoor environment will be discussed.
699
a background monitoring station (Bily Kriz, 49” 30’ N, 18” 23’ E, 940 m.a.s.1.) in the Czech Republic. The purpose of the study is to characterize the influence of various sources in Central Europe on the ambient aerosol. A total of 299 24 h samples were collected during the monitoring campaign and analysed with PIXE (particle induced X-ray emission). The PIXE analysis quantified 18 elements (Si, S, Cl, K, Ca, Ti, V, Mn, Fe, Ni, Cu, Zn, Ga, As, Se, Br, Sr and Pb) in a majority of the samples. An absolute multivariate source/receptor model (absolute principal component analysis; APCA) indicated that there are six relevant source types affecting the Bily Kriz sampling site. These are (1) a combination of ferrous and non-ferrous smelters (K. Mn, Fe, Cu, Zn, Ga and Pb) and traffic (Br and Pb), (2) soil dust (Si, Ca, Ti, Fe, Sr), (3) oil combustion (V, Ni), (4) coal combustion (As, Se), (5) secondary sulphate (S) and (6) sea spray (Cl). The station is believed to be affected by the heavily industrialized region around Katowice and Krakow in Poland, the Czech town of Ostrava, the coal-burning Erzgebirge region in the Czech Republic, the Donetsk region in Ukraine, the Ruhr area in Germany and the Benelux countries. A more detailed analysis of the origin of the various pollutants will be performed by studying three-dimensional back trajectories.
CHARACTERISATION L. Hdkan Environmental
Physics,
Department
OF ROAD DUST Johansson
of Physics,
CTH S-412 96 Giiteborg,
Sweden
Abstract-During dry periods in the winter, road dust particles can dominate over exhaust particles in areas where studded tires are common. An aerosol sampling was made during February and March 1993 near a busy street in Goteborg. The impactor used (virtual dichotomous Sierra-Andersen) fractionates particles into two size intervals, d, c 2.5 pm and 2.5 < d, -c 10 pm. The samples were weighed and analysed for elemental composition with EDXRF technique. Factor analysis was made on the concentrations of the elements to investigate possible sources for the particles. Four factors were clearly identified and are attributed to the following sources: engine emissions from the traffic, road dust, sea salt and long distance transport. Both sea salt and road dust contributed to the variance of the coarse particle mass, but if occasions with westerly winds were excluded the sea salt factor disappears. Regression analysis was made on the coarse particle mass and on elements clearly identified with road dust (occasions with westerly winds were excluded) to give the concentration of these elements in road dust. Major components were Cl (23%), Fe (2.8%), Ca (1.2%) and K (0.75%). Trace elements were Ti (16OOppm), Zn (880 ppm), Pb (670 ppm), Mn (440 ppm), V (160 ppm), Cr (100 ppm) and Ni (50 ppm).
RADON AND AEROSOLS A. Reineking Isotopenlabor
fur biologische
und medizinische
Forschung,
Burckhardtweg
2, D-37077
Giittingen,
Germany
Abstract-The inhalation of the short-lived radon and thoron decay products in the domestic environment yields the largest amount of natural radiation exposure of the human public. From risk calculations it can be estimated that about 5-10% of all lung cancers are due to the inhalation of these natural airborne radionuchdes. The deposition of the “unattached” and aerosol-associated decay products in the human lung depends primarily on the particle size. Besides the airborne activity concentrations and biological parameters, the size characteristics of these decay products and the magnitude of the “unattached” activities are two of the most important parameters in all models for dose calculations. The size characteristics are also essential for understanding and describing the behaviour of the airborne activity in indoor and outdoor environments. The behaviour and the size distribution of the radon decay products in houses are determined by the following processes: (a) (b) (c) (d)
formation of the “unattached” decay products, cluster growth and neutrahsation, attachment to the aerosol particle and formation of a radioactive aerosol, desorption of the particle surfaces, deposition or plate-out on surfaces in a room.
After a brief description of these fundamental processes, measurement techniques for size analysis of short-lived radon/thoron decay products and actual results of aerosol sizes in homes and the outdoor environment will be discussed.