RESUMO
Air activity concentrations of (7)Be in Palermo determined for the period January 1995-December 2002 by gamma-ray spectrometric analysis of particulate samples collected on paper filter by a high-volume sampler (approximately 900 m(3) h(-1)) are reported. The temporal behaviour of (7)Be concentration presents the same characteristics already observed in the measurements carried out over the previous 13-year (1982-1994) investigated period. The mean value of 5.06 mBq m(-3) obtained from the analysis of the 4636 particulate samples collected from 1982 to 2002 can be considered a representative value of (7)Be air concentration at ground level in our geographical zone. The comparison of long-term variation in the (7)Be concentrations with the cyclic solar activity-extended to the whole period of 21 years-confirms the inverse correlation between the two quantities.
Assuntos
Berílio/análise , Radiação Cósmica , Radioisótopos/análise , Monitoramento Ambiental/história , História do Século XX , Itália , Espectrometria gamaRESUMO
A system for low-energy photon spectrometry using a planar germanium detector with appropriate specifications is presented. A spectrometric background investigation has been carried out with various detector shielding arrangements. The characteristics of the system for measurements of 210Pb in air-particulate matter on filters have been determined.
Assuntos
Absorciometria de Fóton/instrumentação , Absorciometria de Fóton/métodos , Poluentes Atmosféricos/análise , Exposição Ambiental/análise , Radioisótopos de Chumbo/análise , Monitoramento de Radiação/métodos , Algoritmos , Germânio , Doses de Radiação , Monitoramento de Radiação/instrumentaçãoRESUMO
210Pb activity concentrations in the air of Palermo were determined by gamma-ray spectrometric analysis of 323 particulate samples collected in the period September 1995-December 1996. For each sample, the air filtered through a cellulose filter paper was 8600 m3 on average. The values of the daily activity concentration of 210Pb were ranging from 136 to 3390 microBq/m3.