アサリによるアンチモン-125の蓄積と体内残留

抄録

Accumulation and retention of ¹²⁵Sb by short-necked clam Tapes japonica were investigated in order to elucidate the uptake mechanism of the nuclide in marine bivalves.
It was found that the accumulation of ¹²⁵Sb by the clam from the environmental water showed an initially relative rapid increase, followed by a gradual increasing pattern during the experimental period. The concentration factors for ¹²⁵Sb in the clam at the end of the experimental period were obtained as 1.2 for the soft part and 4.2 for the shell.
The loss of ¹²⁵Sb accumulated in the whole clam showed an initial decrease, followed by two slow elimination patterns. The long-lived biological half-life for ¹²⁵Sb in the clam was approximately 58 days.
Regarding the influence of chelating agent and co-existing element on the accumulation of ¹²⁵Sb by the clam, it was observed that the addition of stable antimony to the rearing sea watere enhanced the accumulation of ¹²⁵Sb by the soft part and shell of the clam to some extent; whereas, the accumulation of ¹²⁵Sb by the soft part and shell was not depressed in the presence of EDTA.
The accumulation of ¹²⁵Sb by the shell depends mostly on the surface adsorption phenomenon rather than that via metabolic process.