F. Da Costa Fernandes1
1Navy Technology Center
Abstract:
The Brazilian Navy is monitoring the concentration of the radionuclides Cesium 137 and Strontium 90 in samples of water, sediment, fish, and mussels from the marine environment along the Brazilian Coast since 1996. The aim of this work is to establish the background of these radionuclides to assess possible increase of the values due to human activities with nuclear test, nuclear power station accident or other event. The results are stored in a database at the Admiral Paulo Moreira Marine Research Institute. Twenty three sites are annually monitored, between the latitudes of 0º 36’ 49"S and 32º 02’ 06"S and longitudes of 34º 50’ 0" W and 52º 05’ 55" W. The highest values of Cesium 137 measured were 4.1 Bq.m-3 in seawater at Atafona, in 2001; 4.14 Bq.kg-1 in the sediment at Santos, in 1998; 1.72 Bq.kg-1 in fish at Macae, in 2000; and 1.75 Bq.kg-1.in mussels at Angra dos Reis, in 2000. The highest values of Strontium 90 measured were 0.23 Bq.kg-1 in fish at Santos, in 2000 and 0.175 Bq.kg-1 in mussels at Vitoria, in 2006. The only source known of these radionuclides is probably from the nuclear atmospheric tests made before the end of the II World War.
