Vijver Martina G, Koster Marijke, Peijnenburg Willie J G M
Laboratory for Ecological Risk Assessment, National Institute for Public Health and the Environment, Bilthoven, The Netherlands.
Environ Sci Technol. 2007 Apr 1;41(7):2255-60. doi: 10.1021/es061212k.
We studied the interaction between toxic stress and accumulation in the earthworm Aporrectodea caliginosa, as induced by different soil copper pools and soil constituents (especially pH). Earthworms were exposed in quartz sand, spiked soils, and field soils with different Cu concentrations and varying soil composition. The copper content in the earthworms was determined in the following: the cytosolic fraction, a granular fraction and a fraction consisting of tissue fragments, cell membranes and intact cells. The highest amount of Cu was found in the cytosolic fraction. The other fractions varied only slightly in response to changes in any of the copper pools in soil. Cytosolic copper was the best predictor of Cu availability to earthworms collected from soils at constant pH, as statistically significant correlations were obtained with pore water pCu at constant pH in earthworms exposed in quartz sand. This correlation was lost for cytosolic Cu concentrations in earthworms exposed to spiked soils and field soils at differing pHs. Instead, cytosolic copper correlated well to Cu in either pore water or solid phase. Soil pH not only plays an important role in the availability of metals and therefore on their uptake fluxes, but internal competition of Cu2+ and H+ at physiologically active binding sites also explained these apparent contradictions and increased the predictability of body burdens significantly.
我们研究了不同土壤铜库和土壤成分（特别是pH值）所诱导的毒性应激与蚯蚓（Aporrectodea caliginosa）体内累积之间的相互作用。将蚯蚓暴露于不同铜浓度和不同土壤组成的石英砂、加标土壤及田间土壤中。测定蚯蚓体内以下部分的铜含量：胞质部分、颗粒部分以及由组织碎片、细胞膜和完整细胞组成的部分。胞质部分中铜的含量最高。其他部分随土壤中任何一种铜库的变化仅略有差异。在pH恒定的土壤中采集的蚯蚓，胞质铜是蚯蚓可利用铜的最佳预测指标，因为在石英砂中暴露的蚯蚓体内，在pH恒定时，胞质铜与孔隙水pCu之间存在统计学上的显著相关性。对于暴露于不同pH值的加标土壤和田间土壤中的蚯蚓，这种相关性在胞质铜浓度方面消失了。相反，胞质铜与孔隙水或固相中的铜相关性良好。土壤pH不仅在金属的有效性及其吸收通量方面起着重要作用，而且Cu2+和H+在生理活性结合位点的内部竞争也解释了这些明显的矛盾，并显著提高了对体内负荷的预测能力。
