苯并[a]芘在两种海洋生物体内的富集动力学比较

Kinetic study of the bioaccumulation of benzo [a] pyrene in two sea creature's tissues

应用半静态双箱动力学模型在室内模拟了脊尾白虾(Exopalaemon carinicauda)、三疣梭子蟹(Portunus trituberculatus)对苯并[a]芘(benzo[a]pyrene,Ba P)的生物富集实验,通过对富集与释放过程中两种海洋生物体内Ba P的非线性曲线拟合,获得两种海洋生物对Ba P的吸收速率常数k1、释放速率常数k2、生物富集因子BCF、平衡状态下生物体内Ba P含量CAmax、生物学半衰期B1/2等动力学参数.拟合结果显示:脊尾白虾k1的平均值为18.80,k2的平均值为0.08,BCF的平均值为228.02,CAmax的平均值为46.78ng/g,B1/2的平均值为8.95d;三疣梭子蟹k1的平均值为22.55,k2的平均值为0.14,BCF的平均值为158.11,CAmax的平均值为32.70ng/g,B1/2的平均值为5.43d.两种海洋生物对Ba P的k1、k2、BCF均随Ba P暴露浓度的增大而减少,CAmax、B1/2随Ba P暴露浓度的增大而增大.表明Ba P容易在两种海洋生物体内富集,脊尾白虾对Ba P的最高富集量高于三疣梭子蟹,前期富集速率高于后期,对Ba P的释放主要集中在前期,后期释放速率放缓.

Benzo [a] pyrene （BaP） was one of the most important pollutants in the marine environment. To understand the bioaccumulation characteristics of BaP in Exopalaemon carinicauda and Portunus trituberculatus, the kinetic parameters （uptake rate constant （k0, elimination rate constant （k2）, bioaccumulation factor （BCF）, and biological half-life （B1/2） of the BaP bioaccumulation and elimination in crustaceans E. carinicauda and P. trituberculatus tissues were determined used the semi-static two-compartment kinetic model. The range of kl, k2, BCF, CAmax and Bl/2was 12.34 to 24.96, 0.06 to 0.10, 208.41 to 248.03, 12.40 to 93.79ng/g, 6.89 to 11.71 days, respectively, the average value of kl.k2, BCF, CAmax and Bl/2 was 18.80, 0.08, 228.02, 129.07ng/g, 8.95days for BaP in the E. carinicauda tissues. And in the P. trituberculatus tissues, the range of kl, k2, BCF, CAm,x and Bl/2was 8.59to 66.20, 0.09to 0.19, 147.11to 171.79, 8.59 to 66.20ng/g, 3.65 to 7.70 days, respectively, the average value of kl, k2, BCF, Chmax and B1/2 was 22.55, 0.14, 158.11, 32.70ng/g, 5.43 days. It was found that the uptake rate constant （kl）, elimination rate constant （k2） and bioaccumulation factor （BCF） in E. carinicauda and P. trituberculatus tissues generally decreased with the increase in BaP exposure concentration in ambient seawater, the CAmax, B1/2was increased with the increase in BaP exposure concentration in ambient seawater. The results showed that BaP could easily cause bioaccumulation in E. carinicauda and P. trituberculatus tissues, the bioaccumulation contents in E. carinicauda tissues was higher than in P. trituberculatus tissues, the bioaccumulation rate in early stage was higher than the bioaccumulation stage in later, where the release rate of BaP become slower in later stage.