Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing, Jiangsu 210096, China.
State Key Laboratory of Lake Science & Environments, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing, Jiangsu 210008, China.
Sci Total Environ. 2024 May 20;926:171800. doi: 10.1016/j.scitotenv.2024.171800. Epub 2024 Mar 18.
Lake Fuxian, the largest deep freshwater lake in China, has been suffering from increasing ecological and environmental issues along with the rapid urbanization and industrialization in the past 40 years. To better understand the historical pollution of persistent organic pollutants (POPs) in Lake Fuxian, comprehensive analyses of 209 polychlorinated biphenyl (PCB) congeners and 20 organochlorine pesticides (OCPs) were conducted in two intact sediment cores (Core V1 and Core V2). The total mass concentrations of PCBs ranged from 7.60 to 31.47 ng/g (dry weight basis) and 5.55 to 28.90 ng/g during the period of 1908-2019 in Core V1 and 1924-2019 in Core V2, respectively. PCBs exhibited a consecutive increasing trend from 1940s to 2019 in Core V1. The temporal trend of PCBs in Core V2 basically matched to the history of PCB usage and prohibition in China (increasing from 1940s to mid-1960s, a remarkable drop in mid-1970s, and then increasing until 2019). Moreover, low-chlorinated PCBs were dominant among PCB homologues. Mono-CBs, di-CBs, tri-CBs and tetra-CBs accounted for 86.71 %-98.57 % in sediment segments. The PCB sources included unintentional emission and atmospheric deposition, as well as biological transformation. The total mass concentrations of OCPs ranged from 0.74 to 3.82 ng/g in Core V1 and 0.35 to 2.23 ng/g in Core V2, respectively. Similar trend was observed in the two sediment cores with peaks in the early 1990s. The predominant OCPs were γ-hexachlorohexane (γ-HCHs), dieldrin and p,p'-DDD. The ecological risks posed by PCBs and p-p'-DDD in Lake Fuxian were relatively low. In contrast, dieldrin might pose a potential threat to exposed organisms and apparently adverse ecological effects were caused by γ-HCH. This study will provide important baseline information on historical POPs contamination of Lake Fuxian.
中国最大的深水湖泊抚仙湖，在过去 40 年中，随着城市化和工业化的迅速发展，面临着日益严重的生态和环境问题。为了更好地了解抚仙湖持久性有机污染物（POPs）的历史污染情况，对两个完整的沉积岩芯（V1 岩芯和 V2 岩芯）中的 209 种多氯联苯（PCBs）和 20 种有机氯农药（OCPs）进行了综合分析。在 V1 岩芯中，1908 年至 2019 年期间 PCBs 的总质量浓度范围为 7.60 至 31.47ng/g（干重基础），而在 V2 岩芯中，1924 年至 2019 年期间的 PCBs 总质量浓度范围为 5.55 至 28.90ng/g。V1 岩芯中，PCBs 的浓度从 20 世纪 40 年代开始呈连续上升趋势，到 2019 年达到峰值。V2 岩芯中 PCBs 的时间趋势与中国 PCB 使用和禁用的历史基本一致（从 20 世纪 40 年代到 60 年代中期增加，70 年代中期显著下降，然后一直增加到 2019 年）。此外，低氯代 PCBs 在 PCBs 同系物中占主导地位。在沉积段中，单体-CBs、二-CBs、三-CBs 和四-CBs 分别占 86.71%-98.57%。PCBs 的来源包括无意排放、大气沉降以及生物转化。在 V1 岩芯中，OCPs 的总质量浓度范围为 0.74 至 3.82ng/g，而在 V2 岩芯中，OCPs 的总质量浓度范围为 0.35 至 2.23ng/g。在两个沉积岩芯中观察到相似的趋势，峰值出现在 20 世纪 90 年代初。主要的 OCPs 为γ-六氯环己烷（γ-HCHs）、狄氏剂和 p,p'-DDD。抚仙湖 PCBs 和 p,p'-DDD 造成的生态风险相对较低。相比之下，狄氏剂可能对暴露的生物造成潜在威胁，γ-HCH 明显造成了不利的生态影响。本研究将为抚仙湖历史 POPs 污染提供重要的基线信息。
