Original scientific paper
RADIOACTIVE MATTER IN THE ZAGREB AIR FROM 1961 TO 1996
Zdenko Franić
; Institut za medicinska istraživanja i medicinu rada Jedinica za zaštitu od zračenja Ksaverska cesta 2, p.p. 291, HR-10001 Zagreb, Hrvatska
Dobroslav Cesar
; Institut za medicinska istraživanja i medicinu rada Jedinica za zaštitu od zračenja Ksaverska cesta 2, p.p. 291, HR-10001 Zagreb, Hrvatska
Gordana Marović
; Institut za medicinska istraživanja i medicinu rada Jedinica za zaštitu od zračenja Ksaverska cesta 2, p.p. 291, HR-10001 Zagreb, Hrvatska
Jasminka Senčar
; Institut za medicinska istraživanja i medicinu rada Jedinica za zaštitu od zračenja Ksaverska cesta 2, p.p. 291, HR-10001 Zagreb, Hrvatska
Abstract
This paper presents the results of long-term investigations of radioactive matter gathered from the air in the city of Zagreb. The total beta-activity in the air has been measured ever since 1961. A gamma-spectrornetric air analysis has been carried out continuously since 1983, and the determination of 90Sr since 1987. The data presented indicate that the radioactive matter in the Zagreb air, as well as in the whole of Croatia, from 1961 to 1996, has been manifesting a constant exponential decrease in quantity. The only exception was naturally produced 7Be, with almost unchanged specific activity concentrations throughout the measurement period. The main sources of radioactive matter in the air are still the nuclear
explosions conducted in the atmosphere in the 1960s. The Chernobyl nuclear accident caused a significant increase in air radioactivity only in 1986. However, in the few subsequent years it decreased to pre-Chernobyl values. Despite the constant presence of radioactive matter in the Zagreb air, in the last thirty-six years, activity values have never exceeded the legal limit.
Keywords
radioactivity; air; derived activity concentrations; Chernobyl
Hrčak ID:
67764
URI
Publication date:
17.12.1997.
Visits: 1.046 *