Istanbul needs to be protected and constantly monitored water resources due to its increasing population and the decrease in precipitation. This study aims to comprehensively reveal surface sediments collected from reservoirs that supply water to Istanbul concerning POPs (PAHs, PCBs, and OCPs) and heavy metals; to identify possible sources of PAHs, and conduct their ecological risk assessment. Pollution indices in this study were used as contamination degree (CD) contamination factor (CF), geoaccumulation index (I_geo), pollution load index (PLI) and Sediment Quality Guidelines (SQGs). Total PAH concentrations of surface sediments at the sampling points ranged from 46.29 ng/g (A7) to 403.9 ng/g (A15). Benzo(b)fluoranthene (5.647–59.42 ng/g), Pyrene (3.625–83.10 ng/g), Fluoranthene (3.363–66.48 ng/g), Phenanthrene (3.115–52.48 ng/g), Chrysene (3.532–43.98 ng/g), Naphthalene (6.606–36.20 ng/g), Benzo(g,h,i)perylene (3.316–41.73 ng/g) and Indeno(1,2,3-c,d)pyrene (3.453–38.84 ng/g) are the dominant PAH compounds. PAH pollution may be caused by the village-town settlements near the dam and the O7-D020 highway. Total OCP concentration ranged from 2.233 ng/g (A12) to 7.337 ng/g (A1), while total PCB concentration ranged from 0.246 ng/g (A13) to 3.708 ng/g (A1). The lowest total OCP and PCB concentrations were found in surface sediments taken from Kazandere, Papuçdere and Alibey Dam lakes. DDT p,p (0.072–5.177 ng/g) has the highest concentration among all sediment samples. While the most dominant OCP compounds in the samples were DDT p,p, DDE p,p and DDD p,p, HCH alpha, HCH beta, respectively, PCB 153, 138 and 180 were the highest detected PCB congeners in the same samples. Total heavy metal concentration varied from 77,812 mg/kg to 267,072 mg/kg. According to PAH diagnostic analysis, the surface sediments of Terkos, Büyükçekmece, Elmalı, Darlık, Sazlıdere, Alibey and Ömerli Dams were polluted by petrogenic sources, while the surface sediments of Kazandere and Papuçdere Dams were affected by pyrogenic sources. None of the levels of POPs in the samples exceeded the ERM values. Slight and moderate contamination of heavy metals, such as Pb and Zn, were present in most of the sampling points according to CD, CF, PLI and I_geo values. The quality criteria of heavy metals showed that almost all of the sampling points had Cd, Pb and Hg concentrations below the ERL values. The Ni concentrations at most of the sampling points significantly exceeded the ERM values. The concentrations of As, Cr, Cu and especially Ni and Zn exhibit a significant toxic risk to aquatic organisms to sediment quality criteria.

由于人口增加和降水量减少，伊斯坦布尔需要得到保护并不断监测水资源。本研究旨在全面揭示从向伊斯坦布尔供水的水库收集的有关 POPs（PAHs、PCBs 和 OCPs）和重金属的表层沉积物；识别多环芳烃的可能来源，并进行生态风险评估。本研究采用污染指数作为污染度（CD）污染因子（CF）、地积指数（I _geo）、污染负荷指数（PLI）和沉积物质量指标（SQGs）。采样点表面沉积物的 PAH 总浓度范围为 46.29 ng/g (A7) 至 403.9 ng/g (A15)。苯并( b)荧蒽 (5.647–59.42 ng/g), 芘 (3.625–83.10 ng/g), 荧蒽 (3.363–66.48 ng/g), 菲 (3.115–52.48 ng/g), Chrysene (3.532–43.98 ng/g) , 萘 (6.606–36.20 ng/g), 苯并 ( g , h , i) 苝 (3.316–41.73 ng/g) 和茚并 (1,2,3-c,d)芘 (3.453–38.84 ng/g) 是主要的 PAH 化合物。PAH 污染可能由大坝附近的村镇聚落和O7-D020 高速公路造成。OCP 总浓度范围为 2.233 ng/g (A12) 至 7.337 ng/g (A1)，而 PCB 总浓度范围为 0.246 ng/g (A13) 至 3.708 ng/g (A1)。在从 Kazandere、Papuçdere 和 Alibey Dam 湖采集的表层沉积物中发现最低的 OCP 和 PCB 总浓度。DDT p,p (0.072–5.177 ng/g) 在所有沉积物样品中浓度最高。虽然样品中最主要的 OCP 化合物分别是 DDT p,p、DDE p,p 和 DDD p,p、HCH alpha、HCH beta，但 PCB 153、138 和 180 是相同样品中检测到的最高 PCB 同源物。总重金属浓度从 77,812 mg/kg 到 267,072 mg/kg 不等。根据 PAH 诊断分析，Terkos、Büyükçekmece、Elmalı、Darlık、Sazlıdere、Alibey 和 Ömerli 大坝的表层沉积物受到岩源污染，而 Kazandere 和 Papuçdere 大坝的表层沉积物受到热源的影响。样本中的持久性有机污染物含量均未超过 ERM 值。根据 CD、CF、PLI 和 I，大多数采样点存在轻度和中度重金属污染，例如 Pb 和 Zn_地理价值。重金属质量标准显示，几乎所有采样点的 Cd、Pb 和 Hg 浓度均低于 ERL 值。大多数采样点的 Ni 浓度显着超过 ERM 值。As、Cr、Cu，尤其是 Ni 和 Zn 的浓度对沉积物质量标准而言对水生生物具有显着的毒性风险。