Abstract

Spatial distribution of radionuclides in marine sediments from Culebra Bay and the Gulf of Nicoya, Pacific coast, Costa Rica. Ten natural and artificial radionuclides (K40, Cs137, Bi212, Pb212, Bi214, Pb214, Ra226, Ac228, Pa234, U235) in marine sediments were studied in Culebra Bay and the Gulf of Nicoya, both on the Pacific coast of Costa Rica. A freshwater marsh and an offshore island (Coco Island) were used as reference sites. The concentration of radioactive elements from the time of Earth’s formation diminishes in older continental blocks. Higher concentrations are expected in the offshore island, as found in this study. The range of values of these elements are considered normal according to global reports. Some of them, like Potassium 40, seem to have an anthropogenic contribution in the Gulf of Nicoya, possibly related to the activities developed in the adjacent hydrographic basins. In all sampled sites, the artificial element Cesium-137 has been detected within normal ranges and values are very similar to those measured in the coast and in the interior of Costa Rica in previous studies. Rev. Biol. Trop. 56 (Suppl. 4): 83-90. Epub 2009 June 30.
Keywords: Costa Rica, radionuclides, Culebra Bay, Gulf of Nicoya, Cocos Island, marine sediments