In Search of Nontargeted Contaminants of Concern in Surface Waters

研究痕量有机污染物（TrOCs）及其转化产物（TPs）的存在和归趋对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生产和消费者实践的变化，这些变化对环境中TrOC的投入有直接影响。我们选择圣劳伦斯河（SLR）应用拟议的研究计划，因为它是一个流域的主要河流，支持加拿大人口的40%。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，并使用被动采样器和我们研究小组开发的非靶向筛选（NTS）方法识别未知的TrOC。为了优先考虑观察到的化合物，我们将应用时空方案的基础上的检测频率分布图的TrOC在4个不同的位置沿着的SLR。这些图谱将使我们能够整理数据并识别最相关的化合物。 预期结果：在SLR中可能需要监测的未知TrOC列表。（2）在试点流域中观察到的TrOC的TP是否与环境相关？在这里，我们计划研究关注的污染物，如沙坦（心血管疾病的药物）和轮胎添加剂在室外人工流域设施的转化。然后，我们将研究在当地河流中观察到的TP，以验证其环境相关性。 预期成果：确定有关污染物的新的TP及其分子结构，这对于预测其毒性和了解其迁移至关重要。 （3）在SLR中发现的未知TrOC最令人关注的是什么？我们将通过开发两种类型的预测模型来回答这个问题。第一个将用于半定量测定未知TrOC的浓度，而无需分析标准品。第二个是QSAR模型，这将使我们能够预测未知的TrOCs对模型水生物种（大型蚤）的毒性。 预期结果：根据其生态毒理学风险对发现的未知TrOC进行排序。 我的研究计划的总体影响：我的研究计划将有助于：（一）扩大非目标分析技术的适用性，并将其纳入水监测计划;（二）发现未知的TrOC的关注，应在SLR和其他加拿大地表沃茨监测;（三）开发一种新的方法来研究污染物在现实条件下的环境转化;以及（iv）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，因为它们将水污染缓解战略集中在最受关注的TrOC上。

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.