Environmental and Resource Studies Program, Trent University, Peterborough, Ontario, Canada; Nanjing University, School of Environment, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province, People's Republic of China.
J Hazard Mater. 2013 Oct 15;261:746-52. doi: 10.1016/j.jhazmat.2013.03.068. Epub 2013 Apr 6.
Size of organisms is critical in controlling metal bioavailability and bioaccumulation, while mechanisms of size-related metal bioaccumulation are not fully understood. To investigate the influences of different sources of particle-associated Cu on body size-related Cu bioavailability and bioaccumulation, zebra mussels (Dreissena polymorpha) of different sizes were exposed to stable Cu isotope ((65)Cu) spiked algae (Chlorella vulgaris) or sediments in the laboratory and the Cu tissue concentration-size relationships were compared with that in unexposed mussels. Copper tissue concentrations decreased with mussel size (tissue or shell dry weight) in both unexposed and algal-exposed mussels with similar decreasing patterns, but were independent of size in sediment-exposed mussels. Furthermore, the relative contribution of Cu uptake from algae (65-91%) to Cu bioaccumulation is always higher than that from sediments (9-35%), possibly due to the higher bioavailability of algal-Cu. Therefore, the size-related ingestion of algae could be more important in influencing the size-related variations in Cu bioaccumulation. However, the relative contribution of sediment-Cu to Cu bioaccumulation increased with body size and thus sediment ingestion may also affect the size-related Cu variations in larger mussels (tissue weight >7.5mg). This study highlights the importance of considering exposure pathways in normalization of metal concentration variation when using bivalves as biomonitors.
生物体的大小对于控制金属的生物可利用性和生物积累至关重要，而与大小相关的金属生物积累机制尚未完全了解。为了研究不同来源的颗粒相关铜对生物体大小相关铜生物可利用性和生物积累的影响，实验室中使用稳定的铜同位素（(65)Cu）标记的藻类（普通小球藻）或沉积物暴露不同大小的斑马贻贝（Dreissena polymorpha），并比较暴露和未暴露贻贝的铜组织浓度-大小关系。在未暴露和藻类暴露的贻贝中，铜组织浓度随贻贝大小（组织或壳干重）而降低，且具有相似的降低模式，但在沉积物暴露的贻贝中，铜组织浓度与大小无关。此外，藻类（65-91%）对铜生物积累的吸收对铜生物积累的相对贡献始终高于沉积物（9-35%），这可能是由于藻类-Cu 的生物可利用性更高。因此，与大小相关的藻类摄食可能在影响铜生物积累的大小相关变化方面更为重要。然而，随着生物体大小的增加，沉积物-Cu 对铜生物积累的相对贡献增加，因此沉积物摄食也可能影响较大贻贝（组织重量>7.5mg）中与大小相关的 Cu 变化。本研究强调了在使用双壳类动物作为生物监测器时，考虑暴露途径对金属浓度变化归一化的重要性。
