NATURAL RADIOACTIVITY AND EFFECTIVE DOSE DUE TO THE BOTTOM SEA AND ESTUARIES MARINE ANIMALS IN THE COASTAL WATERS AROUND PENINSULAR MALAYSIA

Malaysia is among the countries with the highest fish consumption in the world and relies on seafood as a main source of animal protein. Thus, the radioactivity in the mostly consumed marine animals such as fishes, crustaceans and molluscs collected from the coastal waters around Peninsular Malaysia has been determined to monitor the level of human exposure by natural radiation via seafood consumption. The mean activity concentrations of naturally occurring radionuclides Ra-226 (U-238), Ra-228 (Th-232) and K-40 ranged from 0.67 +/- 0.19 Bq kg(-1) (Perna viridis) to 1.20 +/- 0.70 Bq kg(-1) (Rastrelliger), from 0.19 +/- 0.17 Bq kg(-1) (Teuthida) to 0.82 +/- 0.67 Bq kg(-1) (Caridea) and from 34 +/- 13 Bq kg(-1) (Caridea) to 48 +/- 24 Bq kg(-1) (Teuthida), respectively. The mean annual committed effective dose due to the individual radionuclides shows an order of Ra-228 > Ra-226 > K-40 in all marine samples. The obtained doses are less than the global internal dose of 290 mu Sv y(-1) set by the United Nations Scientific Committee on the Effects of Atomic Radiation, discarding any significant radiological risks to the populace of Peninsular Malaysia.