Van Wensem J, Krijgsman M, Postma J F, Van Westrienen R W, Wezenbeek J M
Biologisch Laboratorium, Vrije Universiteit, Amsterdam, The Netherlands.
Ecotoxicol Environ Saf. 1992 Oct;24(2):203-16. doi: 10.1016/0147-6513(92)90048-8.
The effects of metals on the isopod Porcellio scaber and the implication of metal pollution for the functioning of isopods in soil decomposition processes were determined. The experiments were carried out using two test systems, a simple test container without natural substrate and a micro-ecosystem with leaf litter, the latter being more comparable to the field situation. Metals were offered to the isopods by feeding artificially contaminated litter and litter from contaminated field sites. The Cd concentrations in isopods in test containers with ground litter as food were similar to those in isopods in micro-ecosystems with intact leaves as food. Exposure to artificially contaminated litter with Cd alone or litter from contaminated field sites with Cd, Pb, Zn, and Cu resulted in comparable Cd concentrations in the isopods. Growth of the isopods was not affected by Cd or by the combination of Cd, Pb, Zn, and Cu, but differed between the test systems. Fragmentation activity of isopods decreased in litter containing 155 nmol/g Cd and 33500 nmol/g Zn, sampled at a contaminated field site. CO2 production from micro-ecosystems decreased at a concentration of 1010 nmol/g Cd, but NH4 and NO3 concentrations in the litter did not respond to Cd. Isopod growth was better in micro-ecosystems. These systems are therefore recommended for ecotoxicity tests using isopods. After comparison with literature data it was concluded that the bioavailability of Cd in laboratory tests is often higher than the bioavailability in the field at the same total concentrations. This may be due to environmental heterogeneity; this gives animals food choice and is absent in many laboratory test systems. For the quantification of a laboratory-field extrapolation factor for general use, more detailed information is needed than is available now.
测定了金属对等足类动物鼠妇的影响以及金属污染对鼠妇在土壤分解过程中功能的影响。实验使用了两种测试系统，一种是没有天然基质的简单测试容器，另一种是带有落叶层的微生态系统，后者更接近野外环境。通过投喂人工污染的落叶层和来自污染场地的落叶层，将金属提供给鼠妇。以磨碎的落叶层为食物的测试容器中的鼠妇体内镉浓度，与以完整叶片为食物的微生态系统中的鼠妇体内镉浓度相似。单独暴露于含镉的人工污染落叶层或含镉、铅、锌和铜的污染场地落叶层，会使鼠妇体内镉浓度相当。鼠妇的生长不受镉或镉、铅、锌和铜组合的影响，但在不同测试系统之间存在差异。在一个污染场地采集的含155 nmol/g镉和33500 nmol/g锌的落叶层中，鼠妇的破碎活动减少。微生态系统中二氧化碳的产生在镉浓度为1010 nmol/g时下降，但落叶层中的铵和硝酸盐浓度对镉没有反应。鼠妇在微生态系统中的生长更好。因此，推荐这些系统用于使用鼠妇进行的生态毒性测试。与文献数据比较后得出结论，在相同总浓度下，实验室测试中镉的生物有效性通常高于野外的生物有效性。这可能是由于环境异质性；环境异质性使动物有食物选择，而许多实验室测试系统中不存在这种情况。为了量化普遍适用的实验室-野外外推因子，需要比目前更多的详细信息。
