Mercury (Hg) and polychlorinated biphenyls (PCBs) are widespread environmental toxicants in urban environments with negative impacts to fish health. The present study evaluated the potential association between muscle tissue contaminant (total Hg and total PCB) concentrations and indicators of health in benthic and predatory fish collected from four Forest Preserves of Cook County lakes in the Chicago metropolitan area. Common carp (carp; Cyprinus carpio) and largemouth bass (LMB; Micropterus salmoides) were sampled three times a year (spring, summer, fall) during 2019 and 2020. Water quality analyses (temperature, color, turbidity, dissolved oxygen, total alkalinity, pH, chloride, nitrate, phosphate, ammonium, and pH) were performed concurrently with fish collections. Tissue (skin-on fillet) contaminant concentrations were compared between lake types and fish species and assessed for any relationship with fish morphometric data and pathologic lesions. Main health indicator endpoints included muscle lipid content, parasite burden, and pathologic lesions. Mean total PCB concentrations were greater in carp (203.1 ± 152 µg/kg, wet weight), and mean Hg concentrations were greater in LMB (0.11 ± 0.1 mg/kg, wet weight). In most fish, concentrations of both toxicants surpassed the EPA's lowest threshold to restrict fish consumption for sensitive cohorts (0.029 mg/kg for Hg and 1.5 µg/kg for PCBs). In both species, Hg positively correlated with splenic pigmented macrophage aggregate area (P < 0.001). In carp, Hg also positively correlated with hepatocellular pigmentation (P < 0.01). Mercury correlated with standard length in both species (LMB: P < 0.001, carp: P = 0.95), but polychlorinated biphenyls only correlated with standard length in carp (P < 0.001). No association was found between intraspecific contaminant concentrations and parasite burden, year, or lake type, though differences were noted among individual lakes. The contaminant burden appeared well-tolerated with only mild Hg-associated and no appreciable PCB-associated lesions. However, possible effects on reproduction or behavior were not fully assessed, and future studies are warranted.

汞 (Hg) 和多氯联苯 (PCB) 是城市环境中广泛存在的环境毒物，对鱼类健康有负面影响。本研究评估了从芝加哥大都市区库克县四个森林保护区采集的底栖鱼类和掠食性鱼类的肌肉组织污染物（总汞和总 PCB）浓度与健康指标之间的潜在关联。鲤鱼 (carp; Cyprinus carpio ) 和大嘴鲈鱼 (LMB; Micropterus salmoides) 在 2019 年和 2020 年期间每年（春季、夏季、秋季）采样 3 次。进行了水质分析（温度、颜色、浊度、溶解氧、总碱度、pH、氯化物、硝酸盐、磷酸盐、铵盐和 pH 值）与鱼类收藏同时进行。比较湖泊类型和鱼类种类之间的组织（带皮鱼片）污染物浓度，并评估与鱼类形态数据和病理损伤的任何关系。主要健康指标终点包括肌肉脂质含量、寄生虫负荷和病理损伤。鲤鱼的平均总 PCB 浓度较高（203.1 ± 152 µg/kg，湿重），LMB 的平均汞浓度较高（0.11 ± 0.1 mg/kg，湿重）。在大多数鱼类中，两种有毒物质的浓度都超过了 EPA' s 限制敏感人群鱼类消费的最低阈值（汞为 0.029 毫克/千克，多氯联苯为 1.5 微克/千克）。在这两个物种中，Hg 与脾脏色素巨噬细胞聚集面积呈正相关（P  < 0.001)。在鲤鱼中，Hg 也与肝细胞色素沉着呈正相关（P  < 0.01）。汞与两种鱼的标准长度相关（LMB：P  < 0.001，鲤鱼：P  = 0.95），但多氯联苯仅与鲤鱼的标准长度相关（P  < 0.001）。尽管个别湖泊之间存在差异，但未发现种内污染物浓度与寄生虫负荷、年份或湖泊类型之间存在关联。污染物负担似乎耐受良好，只有轻微的 Hg 相关损伤，没有明显的 PCB 相关损伤。然而，对生殖或行为的可能影响尚未得到充分评估，未来的研究是必要的。