Snail bioaccumulation of triclocarban, triclosan, and methyltriclosan in a North Texas, USA, stream affected by wastewater treatment plant runoff
Snail bioaccumulation of triclocarban, triclosan, and methyltriclosan in a North Texas, USA, stream affected by wastewater treatment plant runoff
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DOI：
10.1897/07-374.1
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发表时间：
2008-08-01
影响因子：
4.1
通讯作者：
La Point, Thomas W.
中科院分区：
文献类型：
--
作者：
Coogan, Melinda A.;La Point, Thomas W.
淡水蜗牛的放牧促进了藻类群落的养分周转。被放牧的藻类隔室可能包含抗微生物剂和代谢物，例如三氯卡班（TCC）、三氯生（TCS）和甲基三氯生（MTCS），这些物质在废水处理厂（WWTP）处理过程中无法完全去除。本研究量化了TCC、TCS和MTCS在Pecan Creek（美国德克萨斯州）排放口的蜗牛生物累积因子（BAF），丹顿市（美国德克萨斯州）污水处理厂的接收流Helisoma trivolvis（Say）是普遍存在的，在标准实验室条件下生长旺盛，导致其选择与刚毛藻属一起进行生物累积研究。沿着为附生植物生长提供基质，刚毛藻属（Cladophora spp.）为H提供食物和住所。三卷虫在被笼化两周后，从污水处理厂排放口收集藻类和蜗牛，沿着收集水柱样品，并通过同位素稀释气相色谱-质谱法分析TCS和MTCS，以及通过液相色谱-质谱法分析TCC。藻类和蜗牛样本进行了分析，暴露前，发现低于实际的定量限的所有抗菌剂。水样中三氯卡班、TCS和MTCS的ppt浓度较低（40-200 ng/L）。三氯卡班、TCS和MTCS在笼中蜗牛样品中升高至低ppb浓度（50-300 ng/g鲜重），在笼中藻类样品中升高至低ppb浓度（50-400 ng/g鲜重）。由此产生的蜗牛和藻类生物累积系数约为三个数量级，这支持藻类和成年笼中蜗牛在这个接收流出口的快速生物累积。结果进一步支持TCC，TCS和MTCS作为良好的候选标记化合物，用于评估痕量污水处理厂污染物的环境分布。
Grazing by freshwater snails promotes nutrient turnover in algal communities. Grazed algal compartments may include antimicrobial agents and metabolites, such as triclocarban (TCC), triclosan (TCS), and methyltriclosan (MTCS), which are incompletely removed by wastewater treatment plant (WWTP) processing. The present study quantifies snail bioaccumulation factors (BAFs) for TCC, TCS, and MTCS at the outfall of Pecan Creek (TX, USA), the receiving stream for the city of Denton (TX, USA) WWTP Helisoma trivolvis (Say) is ubiquitous and thrives under standard laboratory conditions, leading to its choice for this bioaccumulation study in conjunction with Cladophora spp. Along with providing substrate for epiphytic growth, Cladophora spp. provide a source of food and shelter for H. trivolvis. After being caged for two weeks, algae and snails were collected from the WWTP outfall, along with water-column samples, and analyzed by isotope dilution gas chromatography-mass spectrometry for TCS and MTCS and by liquid chromatography-mass spectrometry for TCC. Algal and snail samples were analyzed before exposure and found to be below practical quantitation limits for all antimicrobial agents. Triclocarban, TCS, and MTCS in water samples were at low-ppt concentrations (40-200 ng/L). Triclocarban, TCS, and MTCS were elevated to low-ppb concentrations (50-300 ng/g fresh wt) in caged snail samples and elevated to low-ppb concentrations (50-400 ng/g fresh wt) in caged algal samples. Resulting snail and algal BAFs were approximately three orders of magnitude, which supports rapid bioaccumulation among algae and adult caged snails at this receiving stream outfall. The results further support TCC, TCS, and MTCS as good candidate marker compounds for evaluation of environmental distribution of trace WWTP contaminants.