In Search of Nontargeted Contaminants of Concern in Surface Waters

研究微量有机污染物（troc）及其转化产物（TPs）的发生和归宿，对于防止环境退化和水资源恶化至关重要。我们在这里提出了一种新的方法来跟上制造业和消费者实践的变化，这些变化对环境中troc的输入有直接影响。我们选择圣劳伦斯河（SLR）来应用拟议的研究计划，因为它是一个分水岭的主要河流，养活了约40%的加拿大人口。在短期内（5年），我的研究计划将回答三个重要问题：(1)SLR中最常见的非靶向troc是什么？我们计划进行为期一年的采样活动，并使用我们研究小组开发的被动采样器和非靶向筛选（NTS）方法识别未知的troc。为了对观察到的化合物进行优先排序，我们将采用基于沿SLR的4个不同位置的troc检测频率分布的时空方案。这样的概况将使我们能够整理数据并确定最相关的化合物。预期结果：在SLR中有潜在兴趣监测的未知troc列表。(2)中试流域观测到的有机碳总通量是否与环境相关？在这里，我们计划在室外人工分水岭设施中研究诸如sartans（心血管疾病药物）和轮胎添加剂等污染物的转化。然后，我们将查看在当地河流中观察到的tp，以验证它们与环境的相关性。预期结果：确定受关注污染物的新TPs及其分子结构，这对预测其毒性和了解其运输至关重要。(3)在单反中发现的最令人担忧的未知troc是什么？我们将通过开发两种预测模型来回答这个问题。第一种方法将用于半定量地确定未知TrOCs的浓度，而不需要分析标准。第二个是QSAR模型，该模型将使我们能够预测未知TrOCs对模型水生物种（水蚤）的毒性。预期结果：根据发现的未知TrOCs的生态毒理学风险对其进行排序。我的研究项目的总体影响：我的研究项目将有助于：(i)扩大非目标分析技术的适用性，并将其整合到水监测项目中；（ii）发现应在SLR和其他加拿大地表水中监测的值得关注的未知海洋污染物质；（三）开辟了研究现实条件下污染物环境转化的新途径；（四）开发新的模型，在没有分析标准的情况下预测未知污染物的浓度和毒性。这些贡献对于保护我们的水生生态系统和水资源至关重要，因为它们将减轻水污染的战略重点放在最受关注的外向型国家。

Research on the occurrence and fate of trace organic contaminants (TrOCs) and their transformation products (TPs) is critical to prevent environmental degradation and deterioration of water resources. We propose here a novel way to keep up with the changes in manufacturing and consumer practices that have a direct impact on the inputs of TrOCs in the environment. We selected the St. Lawrence River (SLR) to apply the proposed research program since it is the main river in a watershed that supports ~ 40 % of the Canadian population. Over the short term (5 years), my research program will answer three important questions: (1)What are the most frequently occurring nontargeted TrOCs in the SLR? We plan to perform a year-long sampling campaign and identify unknown TrOCs using passive samplers and a nontargeted screening (NTS) method developed by our research group. To prioritize the compounds observed, we will apply a spatiotemporal scheme based on the detection frequency profiles of TrOCs at 4 different locations along the SLR. Such profiles will allow us to sort out the data and identify the most relevant compounds. Expected outcome : a list of unknown TrOCs that are of potential interest to monitor in the SLR. (2)Are TPs of TrOCs observed in a pilot-scale watershed environmentally relevant? Here we plan to study the transformation of contaminants of concern such as sartans (pharmaceuticals for cardiovascular diseases) and tire additives in an outdoor artificial watershed facility. Then we will look the TPs observed in the local rivers to validate their environmental relevancy. Expected outcome: identify new TPs of contaminants of concern and their molecular structures which are critical to predict their toxicity and to understand their transport. (3)What are the most concerning unknown TrOCs found in the SLR? We will answer this question by developing two types of models of prediction. The first will be used to semi-quantitatively determine the concentration of unknown TrOCs without analytical standards. The second is a QSAR model that will allow us to predict the toxicity of unknown TrOCs towards a model aquatic species (Daphnia magna). Expected outcome: rank the discovered unknown TrOCs according to their ecotoxicological risk. Overall impact of my research program: My research program will contribute to: (i) widening the applicability of nontargeted analysis techniques and integrating them in water monitoring programs; (ii) discovering unknown TrOCs of concern that should be monitored in the SLR and other Canadian surface waters; (iii) developing a new way to study environmental transformation of contaminants under realistic conditions; and (iv) developing new models to predict concentrations and toxicity of unknown contaminants without analytical standards. These contributions are critical to protect our aquatic ecosystems and our water resources by focalizing water contamination mitigation strategies into the most concerning TrOCs.