Tree swallows (Tachycineta bicolor) were used to assess the effectiveness of reducing polychlorinated biphenyl (PCB) exposure to wildlife as a result of contaminated sediment removal at locations across the Great Lakes under two dredging scenarios, full or spot dredging. For comparative purposes, other locations where no dredging occurred were also assessed. Calculating accumulation rate, from the mass of a contaminant in tree swallow eggs and nestling carcasses, is a useful tool to assess the effectiveness of sediment removal. It has the advantage over more commonly used metrics such as cubic yards of sediment removed or kg of a contaminant removed, because it assesses a biotic endpoint that has more societal understanding. Egg and nestling concentrations of total PCBs and accumulation rate (μg of total PCBs accumulated per day) were compared pre- and post-dredge. At the most contaminated site, Waukegan Harbor, Illinois, the accumulation rate decreased by 95% because of dredging. At less contaminated locations in Wisconsin and Ohio, the accumulation rate was reduced by dredging as well, but not to such a large extent (~50%). Even at reference locations, there was a very small amount (0.01–0.06 μg/day) of PCBs accumulated each day because of the prevalence of this contaminant in the environment. The profile of individual PCB congeners also differed pre-and post-dredge and demonstrated significant changes as a result of dredging activities.

树燕 ( Tachycineta bicolor) 用于评估在两种疏浚方案（完全疏浚或点疏浚）下，在五大湖地区清除污染沉积物后，减少多氯联苯 (PCB) 暴露于野生动物的有效性。为便于比较，还评估了其他未发生疏浚的地点。根据树燕卵和雏鸟尸体中污染物的质量计算积累率是评估沉积物去除效果的有用工具。它比更常用的指标（例如去除的沉积物的立方码或去除的污染物的公斤数）更具优势，因为它评估了具有更多社会理解的生物终点。在疏浚前和疏浚后比较鸡蛋和雏鸟的总 PCBs 浓度和积累率（每天积累的总 PCBs 的微克数）。在污染最严重的伊利诺伊州沃基根港，由于疏浚，堆积率下降了 95%。在威斯康星州和俄亥俄州污染较少的地方，疏浚也降低了积累率，但幅度不大（~50%）。即使在参考地点，由于这种污染物在环境中的普遍存在，每天积累的多氯联苯数量也非常少（0.01-0.06 微克/天）。个别 PCB 同系物的分布在疏浚前和疏浚后也有所不同，并且由于疏浚活动而表现出显着变化。即使在参考地点，由于这种污染物在环境中的普遍存在，每天积累的多氯联苯数量也非常少（0.01-0.06 微克/天）。个别 PCB 同系物的分布在疏浚前和疏浚后也有所不同，并且由于疏浚活动而表现出显着变化。即使在参考地点，由于这种污染物在环境中的普遍存在，每天积累的多氯联苯数量也非常少（0.01-0.06 微克/天）。个别 PCB 同系物的分布在疏浚前和疏浚后也有所不同，并且由于疏浚活动而表现出显着变化。