Zidar Primoz, Van Gestel Cornelis A M, Strus Jasna
Department of Biology, Biotechnical Faculty, University of Ljubljana, Vecna pot 111, SI-1000 Ljubljana, Slovenia.
Ecotoxicol Environ Saf. 2009 Nov;72(8):2075-82. doi: 10.1016/j.ecoenv.2009.06.009. Epub 2009 Jul 8.
This study aimed at determining effects of Zn, Cd and their equitoxic mixtures on metal assimilation and food consumption of the terrestrial isopod Porcellio scaber, in relation to metal availability in the food. Cd was four times less water-extractable than Zn. Cd or Zn extractability was affected neither by metal concentration nor by the presence of the other metal. In single metal exposures, assimilation efficiency (AE) was up to five times higher for Cd than for Zn. In a mixture, AE of Cd significantly increased at low mixture concentrations and decreased at high mixture concentrations. AE of Zn significantly increased at intermediate mixture concentrations. Effects of the Zn and Cd mixture on food consumption were additive (28-day EC(50,total)=1.10TU; EC(50,water-extractable)=1.18TU) when based on total and water-extractable concentrations but antagonistic when related to internal metal concentrations in the isopods (EC(50,internal)=1.40TU).
本研究旨在确定锌、镉及其等毒性混合物对陆生等足动物鼠妇金属同化和食物消耗的影响，并探讨其与食物中金属可利用性的关系。镉的水提取率比锌低四倍。镉或锌的提取率不受金属浓度或另一种金属存在的影响。在单一金属暴露中，镉的同化效率（AE）比锌高五倍。在混合物中，镉的AE在低混合物浓度下显著增加，在高混合物浓度下降低。锌的AE在中等混合物浓度下显著增加。基于总浓度和水提取浓度时，锌和镉混合物对食物消耗的影响是相加的（28天EC(50,总)=1.10毒性单位；EC(50,水提取)=1.18毒性单位），但与鼠妇体内金属浓度相关时则是拮抗的（EC(50,体内)=1.40毒性单位）。
