Project 4: Dynamic Transport and Exposure Pathways of Contaminants in Karst Groun

项目摘要 拟议的项目研究与超级基金有关的有机污染物的归宿和迁移， 控制其流动性、持久性、分布和潜在暴露途径的过程，和/或 岩溶地下水系统修复区。该项目的具体目标是描述命运 典型岩溶地下水系统中污染物的运移过程和浓度分布 通过可变导管和/或扩散为主的流动，如在北方波多黎各发现的那些。这个地区有 研究接触超级基金危险化学品及其潜在危险的工作重点领域 导致波多黎各早产率高，是美国司法管辖区中最高的， 全球仅次于马拉维。该项目的重点是氯化挥发性有机化合物 （CVOCs）和邻苯二甲酸酯作为模型污染物，因为它们无处不在， 潜在的健康影响。该研究将建立在物理，数据和协作研究基础设施上 在项目的前三年，研究人员开发了这一系统。 岩溶地下水系统提供了美国40%以上的饮用地下水，发展 在可溶性岩石中，如石灰岩和碳酸盐岩。这些系统中的流动可能通过裂缝发生， 管道和岩石基质。在这样的系统中，管道可以将来自直接排放的水和污染物浓缩。 源和/或扩散流，并将它们快速输送到潜在暴露的排放点，例如泉。 它们还可以将污染物输送到“捕获”扩散流区，这可能导致长期储存， 随后释放污染物。发展评估和预测污染物迁移的能力， 这类含水层中的污染物的潜在暴露对于了解和防止 地下水污染物对健康的影响。 该项目将描述和量化影响岩溶中污染物归宿和迁移的因素 系统.利用实验数据和现场测量，时空污染物分布和 将对运输特性进行表征、量化和统计建模。基本知识 从实验室规模的模型中的水力和运输实验中开发出来的技术将被整合到实地， 通过使用地质统计学方法进行比例尺测量和示踪剂试验。在现场规模，污染物 将测量波多黎各北方岩溶系统地下水威尔斯和泉水中的浓度 在雨季和旱季。现场规模的模型将填充历史污染，水质， 和水文地质数据从北方波多黎各岩溶地下水，并用于描述空间和 污染物分布的时间变化，提供了预测潜在动态暴露的能力， 我们还将继续努力消除岩溶地下水系统中的污染物，并制定保护公众健康的战略。

PROJECT SUMMARY The proposed project studies the fate and transport of Superfund-related organic contaminants and the processes controlling their mobility, persistence, distribution, and paths toward potential exposures and/or remediation zones in karst groundwater systems. The project's specific aims are directed at characterizing fate and transport processes and concentration distributions of contaminants in karst groundwater systems typified by variable conduit and/or diffusion dominated flow, as those found in northern Puerto Rico. This region is the focal area of PROTECT's work to study exposure to Superfund hazardous chemicals and their potential contribution to high rates of preterm birth in Puerto Rico, which are the highest among U.S. jurisdictions, second second only to Malawi globally. The project focuses on chlorinated volatile organic compounds (CVOCs) and phthalates as model contaminants because they are ubiquitous and have been shown to have potential health impacts. The research will build on the physical, data, and collaborative research infrastructure developed by the investigators during the first three years of the project. Karst groundwater systems, which provide over 40% of the groundwater used for drinking in the U.S., develop in soluble rocks, such as limestone and dolomites. Flow in these systems may occur through fractures, conduits, and the rock matrix. In such systems, conduits can concentrate water and contaminants from direct sources and/or diffuse flow and convey them rapidly to potential-exposure discharge points such as springs. They can also convey contaminants to "trapping" diffuse-flow zones, which can result in long-term storage and subsequent release of contaminants. Developing the ability to assess and predict contaminant transport and potential exposure to contaminants in these type of aquifers is essential to understanding and preventing health effects stemming from contaminants in the groundwater. This project will characterize and quantify the factors affecting fate and transport of contaminants in karst systems. Using experimental data and field measurements, spatiotemporal contaminant distributions and transport properties will be characterized, quantified and statistically modeled. Fundamental knowledge developed from hydraulic and transport experiments in laboratory-scale models will be integrated into field- scale measurements and tracer tests through the use of geostatistical methods. At the field scale, contaminant concentrations in groundwater wells and springs in the karst system of northern Puerto Rico will be measured during wet and dry seasons. Field-scale models will be populated with historical contamination, water quality, and hydrogeologic data from the karst groundwater of northern Puerto Rico, and used to describe spatial and temporal changes in contaminant distribution, providing the ability to predict potential dynamic exposure to contaminants in karst groundwater systems and establish strategies to protect public health.