Nursita Ayulungit I, Singh Balwant, Lees Edith
The University of Sydney, NSW 2006, Australia.
Ecotoxicol Environ Saf. 2009 Sep;72(6):1767-73. doi: 10.1016/j.ecoenv.2009.05.009. Epub 2009 Jun 3.
Proisotoma minuta are widely distributed in Australian soils, especially in rehabilitated mine sites and in cotton fields. Laboratory studies were conducted to evaluate the accumulation of cadmium (Cd) in the Collembolan, P. minuta, using four Australian soils. Cadmium accumulation in body tissues was measured by atomic absorption spectroscopy of acid digests of the Collembola. Cadmium soil bioavailability of four Australian soils was determined using a sequential extraction method. The highest soluble-exchangeable Cd concentration was observed in Box Hill soil with the lowest pH, organic carbon, CEC, clay and very low iron content. Robertson soil with high pH, CEC, organic carbon, clay and iron content had the highest Cd organic- and oxide-bound concentrations. This may explain why there was higher Cd accumulation in P. minuta in the Box Hill soil than in the Robertson soil. The Cd uptake of P. minuta was predominantly correlated with soluble-exchangeable Cd concentration in soils followed by organic- and oxide-bound Cd concentrations. Presumably, soluble-exchangeable Cd is more readily available for P. minuta uptake than other Cd fractions.
微小原等节跳虫广泛分布于澳大利亚的土壤中，尤其是在矿山复垦地和棉田中。利用四种澳大利亚土壤，开展了实验室研究以评估弹尾目昆虫微小原等节跳虫体内镉（Cd）的积累情况。通过对弹尾目昆虫进行酸消解后用原子吸收光谱法测定其身体组织中的镉积累量。采用连续提取法测定了四种澳大利亚土壤中镉的土壤生物有效性。在pH值最低、有机碳、阳离子交换量、粘土含量及铁含量极低的Box Hill土壤中，观察到了最高的可溶性可交换镉浓度。pH值、阳离子交换量、有机碳、粘土及铁含量较高的Robertson土壤中，镉的有机结合态和氧化物结合态浓度最高。这或许可以解释为什么Box Hill土壤中的微小原等节跳虫比Robertson土壤中的积累了更多的镉。微小原等节跳虫对镉的吸收主要与土壤中可溶性可交换镉浓度相关，其次与有机结合态和氧化物结合态镉浓度相关。据推测，与其他镉组分相比，可溶性可交换镉更容易被微小原等节跳虫吸收。
