Limits...
Cosmogenic (22)Na, (7)Be and terrestrial (137)Cs, (40)K radionuclides in ground level air samples collected weekly in Kraków (Poland) over years 2003-2006.

Błażej S, Mietelski JW - J Radioanal Nucl Chem (2014)

Bottom Line: Presented frequency distributions for activity concentration and correlation between the obtained results are discussed.The activity concentration results confirmed seasonal variation of activity to be different for all the investigated radionuclides.Limitations of the applied model were identified.

View Article: PubMed Central - PubMed

Affiliation: The Henryk Niewodniczański Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Kraków, Poland.

ABSTRACT

A low background gamma spectrometer with an Etruscan, 2500 years old lead shield and a muon veto detector were applied to study (22)Na and (7)Be activity concentration in ground level air aerosol samples collected weekly over the years 2003-2006 in Kraków. Each sample was formed with ca 100 000 m(3) of passed air, collected with two parallel ASS-500 high volume air samplers. The results for (40)K and (137)Cs are also presented for reference and comparison. Presented frequency distributions for activity concentration and correlation between the obtained results are discussed. The activity concentration results confirmed seasonal variation of activity to be different for all the investigated radionuclides. Moreover, the seasonal variation in nucleus activity ratio was also noticed for (22)Na and (7)Be. Cosmogenic radionuclides being mainly of stratospheric origin, are subsequently attached to fine aerosols, via which they are transported to the ground level air. The mean aerosol transport time within the troposphere was estimated as equal to 7.5 days on average, reaching even 50 days in warm seasons. Limitations of the applied model were identified.

No MeSH data available.


Correlation plots for 7Be and 22Na activity concentration in ground level air in Kraków in years 2003–2006
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Fig4: Correlation plots for 7Be and 22Na activity concentration in ground level air in Kraków in years 2003–2006

Mentions: High correlation can be expected for activity concentration of radionuclides of similar origin: cosmogenic (7Be, 22Na) and terrestrial (137Cs, 40K). Table 2 presents the correlation between activity concentration for all four radionuclides and four seasons. The correlation between 7Be and 22Na (see also Fig. 4) was the highest for spring (squared Pearson factor r2 = 0.49, significance level p < 0.0001) and only slightly lower was for summer (r2 = 0.43, p < 0.0001), whereas it was much lower for autumn (r2 = 0.30, p = 0.0022), and the lowest value was found for winter (r2 = 0.12, p = 0.0215). The correlation plot (Fig. 4) for winter might suggest at least two correlation lines to be present: one with a slope of about 6 × 103 (similar to that of warm seasons), and the second one, much stepper with 2 × 104.Table 2


Cosmogenic (22)Na, (7)Be and terrestrial (137)Cs, (40)K radionuclides in ground level air samples collected weekly in Kraków (Poland) over years 2003-2006.

Błażej S, Mietelski JW - J Radioanal Nucl Chem (2014)

Correlation plots for 7Be and 22Na activity concentration in ground level air in Kraków in years 2003–2006
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4514665&req=5

Fig4: Correlation plots for 7Be and 22Na activity concentration in ground level air in Kraków in years 2003–2006
Mentions: High correlation can be expected for activity concentration of radionuclides of similar origin: cosmogenic (7Be, 22Na) and terrestrial (137Cs, 40K). Table 2 presents the correlation between activity concentration for all four radionuclides and four seasons. The correlation between 7Be and 22Na (see also Fig. 4) was the highest for spring (squared Pearson factor r2 = 0.49, significance level p < 0.0001) and only slightly lower was for summer (r2 = 0.43, p < 0.0001), whereas it was much lower for autumn (r2 = 0.30, p = 0.0022), and the lowest value was found for winter (r2 = 0.12, p = 0.0215). The correlation plot (Fig. 4) for winter might suggest at least two correlation lines to be present: one with a slope of about 6 × 103 (similar to that of warm seasons), and the second one, much stepper with 2 × 104.Table 2

Bottom Line: Presented frequency distributions for activity concentration and correlation between the obtained results are discussed.The activity concentration results confirmed seasonal variation of activity to be different for all the investigated radionuclides.Limitations of the applied model were identified.

View Article: PubMed Central - PubMed

Affiliation: The Henryk Niewodniczański Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Kraków, Poland.

ABSTRACT

A low background gamma spectrometer with an Etruscan, 2500 years old lead shield and a muon veto detector were applied to study (22)Na and (7)Be activity concentration in ground level air aerosol samples collected weekly over the years 2003-2006 in Kraków. Each sample was formed with ca 100 000 m(3) of passed air, collected with two parallel ASS-500 high volume air samplers. The results for (40)K and (137)Cs are also presented for reference and comparison. Presented frequency distributions for activity concentration and correlation between the obtained results are discussed. The activity concentration results confirmed seasonal variation of activity to be different for all the investigated radionuclides. Moreover, the seasonal variation in nucleus activity ratio was also noticed for (22)Na and (7)Be. Cosmogenic radionuclides being mainly of stratospheric origin, are subsequently attached to fine aerosols, via which they are transported to the ground level air. The mean aerosol transport time within the troposphere was estimated as equal to 7.5 days on average, reaching even 50 days in warm seasons. Limitations of the applied model were identified.

No MeSH data available.