hrvatski

Radioaktivnost i elementi platinske skupine u zraku Zagreba

Systematic monitoring of radioactivity in the environment of the Republic of Croatia has been performed at the Institute of Medical Research and Occupational Health (IMROH) since 1959, while air quality research began in the 1960s. Various analyses are carried out, including gamma spectroscopic measurements of air samples and physicochemical analysis of particulate matter. 40K and 210Pb are terrestrial radionuclides of natural origin. Platinum group elements due to their specific properties have significant application in different branches of the industry. The most widely used applications are those of platinum (Pt), palladium (Pd) and rhodium (Rh) in the production of automotive catalytic converters, whose purpose is to reduce the emission of harmful gases from motor vehicles to the air. This paper presents the results of measurements of 40K and 210Pb radioactivity and mass concentrations of Pt, Pd and Rh bound to airborne particulate matter with an aerodynamic diameter smaller than 10 μm (PM10) during 2016 at one location in Zagreb (urban background station). Average activities of 40K and 210Pb were 0.011 mBq m-3 and 0.587 mBq m-3, respectively. Average mass concentrations of Pt, Pd and Rh were 0.091 pg m-3, 1.895 pg m-3 and 0.734 pg m-3, respectively. All of the measured elements/isotopes showed characteristic variations with the highest values during the colder part of the year. Concentration ratio Pt:Pd:Rh was 1.1:6.7:1 which is similar to the ratio of these elements in newer automobile catalytic converters (0-1 : 8-16:1). Traffic is indicated as a dominant source of Pt, Pd and Rh at this location in Zagreb. A statistically significant correlation (p<0.05) was found between Pd and 40K, and between Pt and 210Pb. Rh correlated with Pt, Pd and 210Pb. These results could indicate their common origin, but to make a final conclusion it is necessary to continue the investigation on a larger number of samples.

40K i 210Pb radioaktivnost, lebdeće čestice, paladij, platina, rodij

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