Gonzales Annelise K, Donaher Sarah E, Wattier Bryanna D, Martinez Nicole E
Department of Environmental Engineering and Earth Sciences, Clemson University, Clemson, South Carolina, USA.
Center for Nuclear Environmental Engineering Sciences and Radioactive Waste Management, Clemson, South Carolina, USA.
Environ Toxicol Chem. 2023 Nov;42(11):2412-2421. doi: 10.1002/etc.5720. Epub 2023 Aug 22.
A variety of processes, both natural and anthropogenic, can have a negative impact on surface waters, which in turn can be detrimental to human and environmental health. Few studies have considered the ecotoxicological impacts of concurrently occurring contaminants, and that is particularly true for mixtures that include contaminants of emerging concern (CEC). Motivated by this knowledge gap, the present study considers the potential ecotoxicity of environmentally relevant contaminants in the representative aquatic plant Lemna minor (common duckweed), a model organism. More specifically, biological effects associated with exposure of L. minor to a ubiquitous radionuclide (uranium [U]) and a fluorinated organic compound (perfluorooctanoic acid [PFOA], considered a CEC), alone and in combination, were monitored under controlled laboratory conditions. Lemna minor was grown for 5 days in small, aerated containers. Each treatment consisted of four replicates with seven plants each. Treatments were 0, 0.3, and 3 ppb PFOA; 0, 0.5, and 5 ppb U; and combinations of these. Plants were observed daily for frond number and signs of chlorosis and necrosis. Other biological endpoints examined at the conclusion of the experiment were chlorophyll content and antioxidant capacity. In single-exposure experiments, a slight stimulatory effect was observed on frond number at 0.3 ppb PFOA, whereas both concentrations of U had a detrimental effect on frond number. In the dual-exposure experiment, the combinations with 5 ppb U also had a detrimental effect on frond number. Results for chlorophyll content and antioxidant capacity were less meaningful, suggesting that environmentally relevant concentrations of PFOA and U have only subtle effects on L. minor growth and health status. Environ Toxicol Chem 2023;42:2412-2421. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
多种自然和人为过程会对地表水产生负面影响，进而损害人类健康和环境健康。很少有研究考虑同时存在的污染物的生态毒理学影响，对于包含新出现的关注污染物（CEC）的混合物而言尤其如此。受这一知识空白的驱动，本研究考察了具有代表性的水生植物小浮萍（Lemna minor，一种模式生物）中与环境相关的污染物的潜在生态毒性。更具体地说，在受控实验室条件下，监测了小浮萍单独和联合暴露于一种普遍存在的放射性核素（铀[U]）和一种氟化有机化合物（全氟辛酸[PFOA]，被视为一种CEC）时的生物效应。小浮萍在小型充气容器中培养5天。每个处理组有四个重复，每组七株植物。处理组分别为0、0.3和3 ppb的PFOA；0、0.5和5 ppb的U；以及它们的组合。每天观察植物的叶片数量以及黄化和坏死迹象。在实验结束时检测的其他生物终点包括叶绿素含量和抗氧化能力。在单暴露实验中，0.3 ppb的PFOA对叶片数量有轻微刺激作用，而两种浓度的U对叶片数量均有不利影响。在双暴露实验中，含有5 ppb U的组合对叶片数量也有不利影响。叶绿素含量和抗氧化能力的结果意义较小，表明与环境相关浓度的PFOA和U对小浮萍的生长和健康状况仅有细微影响。《环境毒理学与化学》2023年；42:2412 - 2421。© 2023作者。《环境毒理学与化学》由威利期刊有限责任公司代表SETAC出版。
