A study on natural and anthropogenic radionuclides in farmed fish and shellfish in Singapore

With a target to increase local seafood production to fulfil Singapore's goal of producing 30% of its nutritional needs by 2030, the local population is expected to consume more seafood produced domestically as part of their daily diet. It is therefore valuable to acquire radioactivity levels to evaluate the radiation exposure to the public from consumption of these domestic seafood produce. In this study, we evaluated domestically farmed fish and shellfish for natural and anthropogenic radionuclides using gamma spectrometry and inductively coupled plasma mass spectrometry. Mean activity concentrations of ²²⁸Ra, ²²⁶Ra, ⁴⁰K, ¹³⁷Cs, ²³⁸U and ²³²Th in farmed fish were determined to be 0.166 Bq/kg, 0.277 Bq/kg, 119.9 Bq/kg, 0.069 Bq/kg, 0.0190 Bq/kg and 0.0026 Bq/kg respectively, while activity levels observed in shellfish were 0.272 Bq/kg for ²²⁸Ra, 0.195 Bq/kg for ²²⁶Ra, 39.2 Bq/kg for ⁴⁰K, < MDA for ¹³⁷Cs, 0.2390 Bq/kg for ²³⁸U and 0.2013 Bq/kg for ²³²Th. The derived annual total effective dose arising from the intake of radionuclides has also been found to be significantly lower than the maximum dose of 1 mSv/yr allowable to the public. (author)