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Abstract: Three kinds of fish from a natural fishpond in the north of Taiwan were collected and analyzed in this study. The three species were non-predatory Ctenopharyn odon idellus, predatory Aristichthys nobilis and predatory Mylopharyngodon piceus. The activity concentrations of 90Sr in bone and edible flesh of fish, as well as in water and soil of fishpond were measured by using the radiochemical analysis. Additionally, the concentration of stable calcium in fish bone, [Ca]bone, and that of stable strontium in fish bone, [Sr]bone, were measured by ICP-AES. From the results, the concentration factors of 90Sr, CF(90Sr), in fish bone was no statistic difference between non-predatory and predatory fish. Besides, the accumulation of 90Sr in the non-predatory fish remarkably decreased with increasing the fish weight. As for the predatory fish, they both showed no statistically significant correlations between the 90Sr activity concentration and the fish weight. Regarding the activity concentrations of 90Sr in fish bone, all the fish were observed positively correlated with the measured [Sr]bone. [Copyright &y& Elsevier]

Abstract: In this study, to improve the problem of waiting for the growth of 90Y for Cerenkov counting and save the time of 90Sr analysis, an organic cocktail sample was counted by a liquid scintillation counting system immediately after the purification of 90Sr without waiting for the growth of 90Y. The chemical separation and the measurement procedures for 90Sr radioactivity analysis can be completed in 24h. In order to verify the performance of the improved method, the activity of 90Sr in six environmental reference samples was determined after radiochemical purification with a crown-ether resin column, and subsequent measurement by both the Cerenkov and the organic cocktail liquid scintillation counting methods. The results revealed that the organic cocktail liquid scintillation counting was quicker and had higher efficiency and lower minimum detectable activity (MDA) than the Cerenkov counting. [Copyright &y& Elsevier]

Abstract: Oysters around the coast of Taiwan were collected, dried, spiked with a 209Po tracer for yield, digested with concentrated HNO3 and H2O2, and finally dissolved in 0.5N HCl. The polonium was then spontaneously deposited onto a silver disc, and the activity of 210Po was measured using an alpha spectrum analyzer equipped with a silicon barrier detector. Meanwhile, the internal effective dose of 210Po coming from the intake of oysters by Taiwanese was evaluated. The results of the present study indicate that 210Po average activity concentrations ranged from 23.4±0.4 to 126±94Bqkg−1 of fresh oysters. The oysters coming from Penghu island and Kinmen island regions contain higher concentrations of 210Po in comparison with oysters from other regions of Taiwan. The value of 210Po weighted average activity concentrations for all oyster samples studied is 25.9Bqkg−1. The annual effective dose of Taiwanese due to the ingestion of 210Po in oysters was estimated to be 4.1×10−2 mSvy−1. [Copyright &y& Elsevier]

Abstract: Radio pollutant removal is one of several priority restoration strategies for the environment. This study assessed the effect of low molecular weight organic acid on the lability and mechanisms for release of 137Cs from contaminated soils. The amount of 137Cs radioactivity released from contaminated soils reacting with 0.02M low molecular weight organic acids (LMWOAs) specifically acetic, succinic, oxalic, tartaric, and citric acid over 48h were 265, 370, 760, 850, and 1002Bqkg−1, respectively. The kinetic results indicate that 137Cs exhibits a two-step parabolic diffusion equation and a good linear relationship, indicating that the parabolic diffusion equation describes the data quite well, as shown by low p and high r 2 values. The fast stage, which was found to occur within a short period of time (0.083–3h), corresponds to the interaction of LMWOAs with the surface of clay minerals; meanwhile, during the slow stage, which occurs over a much longer time period (3–24h), desorption primarily is attributed to inter-particle or intra-particle diffusion. After a fifth renewal of the LMWOAs, the total levels of 137Cs radioactivity released by acetic, succinic, oxalic, tartaric, and citric acid were equivalent to 390, 520, 3949, 2061, and 4422Bqkg−1 soil, respectively. H+ can protonate the hydroxyl groups and oxygen atoms at the broken edges or surfaces of the minerals, thereby weakening Fe–O and Al–O bonds. After protonation of H+, organic ligands can attack the OH and OH2 groups in the minerals easily, to form complexes with surface structure cations, such as Al and Fe. The amounts of 137Cs released from contaminated soil treated with LMWOAs were substantially increased, indicating that the LMWOAs excreted by the roots of plants play a critical role in 137Cs release. [Copyright &y& Elsevier]