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Study on the Accumulation and Elimination of Pb and Cd in Patinopecten yessoensis

The accumulation and elimination of heavy metals in shellfish are greatly affected by many factors including the type of the heavy metal, the size, tissue, and organ of the shellfish. External environmental factors are also involved such as the temperature, p H, and the concentrations of the heavy metal. Here we investigated the accumulation and elimination of two heavy metals(Pb and Cd) in Patinopecten yessoensis in a semi-static system. We measured the concentrations of Pb and Cd in different organs of P. yessoensis with different sizes. Using the two-compartment model with non-linear curve fitting, we obtained kinetic parameters such as bioconcentration factor(BCF), uptake rate constant(k1), elimination rate constant(k2) and biological half-life(B1/2). P. yessoensis had high capacity of the bioaccumulation and elimination of Cd and Pb. BCF for Pb in large-size scallops and small-size scallops were 1671 and 896 respectively, and the values for Cd were 7433 and 1123 respectively. This indicated that the size of P. yessoensis had impact on the accumulation of heavy metals, and that large-size scallops had higher capacity. Given the same size, BCF for Cd was higher than Pb, which implied a preference in the bioaccumulation of Cd. The accumulation of Pb in different organs showed the order gill visceral mass adductor muscle, and the order for Cd was visceral mass gill adductor muscle. The B1/2 for both Pb and Cd was higher in large-size P. yessoensis, which suggested that large-size scallops were more capable of eliminating Pb and Cd. The elimination rate of Cd in the visceral mass was the highest among the organs, and there was no difference between the gill and the adductor muscle. Our study provided insights into the toxic effects of heavy metals in shellfish.