Distribution of ¹³⁷Cs activities in clams, Tivela mactroidea collected along the northern coast of Venezuela and the island of Margarita

Abstract

Clam meats were obtained directly from the fishermen on the beaches in front of where the clams were collected at eight sites; seven along the northern coast of Venezuela and one on the northern coast of the island of Margarita (Venezuela). Marine sediments were also collected in the same corresponding areas as the clams. ¹³⁷Cs was determined both in clam meats and the marine sediments by high resolution gamma-ray spectrometry employing a hyperpure germanium detector. About 5 kg portions of clam meats were washed and dried in the laboratory, before 500 cm³ volumes were transferred and weighed in the measuring containers. Similarly, 500 cm³ volumes of marine sediments that were dried and ground to pass a 85 μm sieve were transferred to the measuring containers. The samples were counted for 150,000 seconds of real time. The ¹³⁷Cs activity of the clam meats ranged from <0.011 Bq·kg⁻¹ (our detection limit) to 0.36 Bq·kg⁻¹ (dried weigh). These values are all within the range of values considered for environmental fallout from the nuclear weapons tests. Finally, all the values for the corresponding marine sediments were below our detection limit of 0.1 Bq·kg⁻¹ of ¹³⁷Cs (dried weigh).