School of Geographic and Oceanographic Sciences, Nanjing University, 163 Xianlin Road, Nanjing, Jiangsu 210023, China.
School of Geographic and Oceanographic Sciences, Nanjing University, 163 Xianlin Road, Nanjing, Jiangsu 210023, China.
Environ Pollut. 2018 Sep;240:709-716. doi: 10.1016/j.envpol.2018.05.006. Epub 2018 May 16.
Long-term trends of sediment compositions are important for assessing the impact of human activities on the sediment and protecting the sediment environment. In this study, based on the contents of heavy metals and the Pb isotope ratios in lake sediments, atmospheric dustfall and soil in Yixing, China, the representative heavy metals (Zn, Pb, Cr and Cd) in lake sediments from western Taihu Lake were studied. The evolution history of heavy metals in the local environment was constructed for the past 100 years. From 1892 to the 1990s, the anthropogenic fluxes of the representative heavy metals were negligible, indicating minimal anthropogenic emissions of heavy metals. Since the 1990s, anthropogenic fluxes of the representative heavy metals began to increase, concurrent with the economic growth and development in the western Taihu Lake Basin after the Chinese economic reform. The maximum flux percentage of the heavy metals in the sediments, caused by human activities, is 23.0% for Zn, 31.6% for Pb, 39.5% for Cr and 85.3% for Cd, indicating that most of the Cd comes from human activities. The Cd content in the western Taihu Lake Basin was significantly higher than that in the other areas, and the rapid development of the industry in the western Taihu Lake Basin and ceramics in Yixing led to the enrichment of heavy metals in local sediments. Since the 21st century, measures have been taken to control the pollution of heavy metals, including the increase in local government attention and the deployment of environmental monitoring technology. However, heavy metal content remains high, and the Pb content is still increasing. The ratios of Pb isotopes show that the main sources of heavy metals in the western Taihu Lake sediments, the local soil of Yixing and the atmospheric dustfall are coal combustion, leaded gasoline combustion, industrial wastewater and domestic sewage.
在过去的 100 年里，构建了当地环境中重金属的演变历史。1892 年至 20 世纪 90 年代，代表重金属的人为通量可以忽略不计，表明重金属人为排放很少。自 20 世纪 90 年代以来，随着中国经济改革后太湖西部流域经济的增长和发展，代表重金属的人为通量开始增加。人类活动引起的重金属在沉积物中的最大通量百分比为 Zn 的 23.0%、Pb 的 31.6%、Cr 的 39.5%和 Cd 的 85.3%，表明大部分 Cd 来自人类活动。太湖西部流域的 Cd 含量明显高于其他地区，太湖西部流域工业和宜兴陶瓷的快速发展导致当地沉积物中重金属的富集。自 21 世纪以来，已经采取了控制重金属污染的措施，包括提高地方政府的重视和部署环境监测技术。然而，重金属含量仍然很高，Pb 含量仍在增加。Pb 同位素比值表明，太湖西部湖底沉积物、宜兴当地土壤和大气降尘中重金属的主要来源是煤炭燃烧、含铅汽油燃烧、工业废水和生活污水。
