Vingskes Anna Katharina, Spann Nicole
Department of Animal Ecology, Faculty of Biology, Bielefeld University, Bielefeld, Germany.
Ecotoxicology. 2018 May;27(4):420-429. doi: 10.1007/s10646-018-1905-9. Epub 2018 Feb 6.
Many widely used healthcare products contain antiseptics, whose persistence in aquatic environments, soils, and sediments leads to the contamination of ecosystems and adversely affects wildlife. Recently, the impact not only of high but also low doses of contaminants and mixtures of several chemicals has become a focus of concern. In this study, toxicity tests of the antiseptics triclosan (TCS) and triclocarban (TCC) were performed in an aquatic test medium using the nematode Caenorhabditis elegans. Nominal concentrations of TCS and TCC were tested in separate single-substance toxicity tests (96-h-exposure), focussing on growth and reproduction endpoints. Median effective concentrations (EC50s) from the single-substance tests were subsequently used to set up five different ratios of TCS:TCC mixtures leading to the same toxicity. Six dilutions of each mixture ratio were tested for effon reproduction of C. elegans. In the single-substance tests, TCC was about 30 times more toxic than TCS when considering effects on growth and concerning reproduction, TCC was about 50 times more toxic than TCS. For both substances, the toxic effect on reproduction was more pronounced than the one on growth. Low doses of TCS (1-10 µmol L) stimulated reproduction by up to 301% compared to the control, which might be due to endocrine disruption or other stress-related compensation responses (hormesis). Neither antiseptic stimulated growth. In the mixtures, increasing amounts of TCC inhibited the stimulatory effects of TCS on reproduction. In addition, the interactions of TCS and TCC were antagonistic, such that mixtures displayed lower toxicity than would have been expected when TCS and TCC mixtures adhered to the principle of concentration addition.
许多广泛使用的医疗保健产品都含有防腐剂，这些防腐剂在水生环境、土壤和沉积物中的持久性会导致生态系统受到污染，并对野生动物产生不利影响。最近，不仅高剂量，而且低剂量的污染物以及几种化学物质的混合物所产生的影响已成为人们关注的焦点。在本研究中，使用线虫秀丽隐杆线虫在水生测试介质中对抗菌剂三氯生（TCS）和三氯卡班（TCC）进行了毒性测试。在单独的单物质毒性测试（96小时暴露）中测试了TCS和TCC的标称浓度，重点关注生长和繁殖终点。随后，将单物质测试中的半数有效浓度（EC50）用于设置导致相同毒性的五种不同比例的TCS:TCC混合物。对每种混合物比例的六种稀释液进行了秀丽隐杆线虫繁殖效应测试。在单物质测试中，考虑到对生长的影响，TCC的毒性比TCS高约30倍；就繁殖而言，TCC的毒性比TCS高约50倍。对于这两种物质，对繁殖的毒性作用比对生长的毒性作用更明显。与对照组相比，低剂量的TCS（1-10μmol/L）可使繁殖率提高301%，这可能是由于内分泌干扰或其他与应激相关的补偿反应（兴奋效应）。两种防腐剂均未刺激生长。在混合物中，TCC含量的增加抑制了TCS对繁殖的刺激作用。此外，TCS和TCC之间的相互作用是拮抗的，因此混合物的毒性低于TCS和TCC混合物遵循浓度相加原则时预期的毒性。
