Date of Award
Level of Access Assigned by Author
Doctor of Philosophy (PhD)
Charles T. Hess
Second Committee Member
Third Committee Member
Additional Committee Members
7Be and 210Pb activities were measured in air sampling filters collected at The University of Maine campus from 2014 to 2019. The activities of 7Be were in the range of 1.178-98.8 Bq, with an average value of 32.13 Bq. The activities of 210Pb were in the range of 0.091 to 13.64 Bq, and an average value of 3.029 Bq. The distributions of activity for both radionuclides are lognormal. Both 7Be and 210Pb show seasonal variation with maximum values in the summer and minimum values in the fall, and the 7Be/210Pb ratio shows a clear seasonal variation with maxima in the spring and summer and minima in the winter. The measured activities of the two radionuclides are correlated (R=0.593, P
These results are compared with a sample of results from the literature, selected for similar latitude, showing consistency with some sampling sites in Europe, notably those with some influence from both oceanic and continental air flows. The likely mechanism for the seasonal variation in both radionuclides is increased atmospheric mixing in the warmer months, although a possible explanation for the variation in 7Be/210Pb ratio is influx of oceanic air at the sampling site during the spring. Further research includes correlating the 7Be data with the 11-year solar cycle and adjusting for its effects, and a more detailed analysis and classification of air flows arriving at the sampling site, and correlation between different air masses (oceanic versus continental, for example) and the measured radionuclide activities.
Deaton, James W., "Measurement of Airborne Radionuclides and Their Relation to Weather Patterns at Orono, ME" (2022). Electronic Theses and Dissertations. 3651.