Supplementary data for "Co-deployment of passive samplers and mussels reveals major source of ongoing PCB inputs to the Anacostia River in Washington DC"

Remedial investigations of sites contaminated with legacy pollutants like polychlorinated biphenyls (PCBs) have traditionally focused on mapping sediment contamination to develop a site conceptual model and select remedy options. This sediment-focused approach often leads to an incomplete understanding of the impacts of ongoing inputs to the water column and over-estimation of potential effectiveness of sediment remediation. Here we demonstrate the utility of co-deployment of passive equilibrium samplers and freshwater mussels as dual lines of evidence to identify ongoing sources of PCBs from eight main tributaries of the Anacostia River in Washington, DC that has been historically polluted from industrial and other human activities. The freely dissolved PCB concentrations measured using passive samplers tracked well with the accumulation in mussels and allowed predictions of biouptake within a factor of 2 for total PCBs and a factor of 4 for most congeners. One tributary was identified as the primary source of PCBs to the water column and became a focus of additional ongoing investigations. Co-deployment of passive samplers and mussels provide strong lines of evidence to identify ongoing sources critical to control to achieve river water quality standards and reduce bioaccumulation in the aquatic food web.针对多氯联苯（polychlorinated biphenyls, PCBs）这类遗留污染物污染场地的修复调查，传统上聚焦于绘制沉积物污染图谱，以构建场地概念模型并选定修复方案。这种以沉积物为核心的研究思路，往往导致对水层中持续输入物的影响认识不全面，同时高估了沉积物修复的潜在成效。本研究证实，将被动平衡采样器（passive equilibrium samplers）与淡水贻贝联合部署作为双重证据链，可用于识别美国华盛顿特区阿纳卡斯蒂亚河八大主要支流的多氯联苯持续污染源——该流域曾因工业及其他人类活动遭受历史性污染。通过被动采样器测得的自由溶解态多氯联苯浓度，与贻贝体内的污染物累积量匹配度良好，据此可预测生物吸收情况：总多氯联苯的生物吸收偏差在2倍以内，多数同系物的偏差则在4倍以内。研究明确其中一条支流为阿纳卡斯蒂亚河水体多氯联苯的主要污染源，成为后续额外调查的重点对象。被动采样器与贻贝的联合部署，可为识别关键持续污染源提供强有力的证据支撑，这些污染源的管控对于达到河流水质标准、降低水生食物网中的生物富集水平至关重要。