中国地理科学 ›› 2016, Vol. 26 ›› Issue (6): 755-769.doi: 10.1007/s11769-016-0835-9

• 论文 • 上一篇    下一篇

A 150-year Isotopic Record of Lead Deposition in Yancheng Coastal Wetland, China

BAO Kunshan1, SHEN Ji1, QUAN Guixiang2, LIU Fugang3   

  1. 1. State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China;
    2. School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China;
    3. School of Science, Qiqihar University, Qiqihar 161006, China
  • 收稿日期:2015-06-25 修回日期:2015-10-18 出版日期:2016-12-27 发布日期:2016-11-05
  • 通讯作者: BAO Kunshan.E-mail:ksbao@niglas.ac.cn E-mail:ksbao@niglas.ac.cn
  • 基金资助:

    Under the auspices of Natural Science Foundation of Jiangsu Province, China (No. BK20131058), NSFC-CNRS (National Natural Science Foundation of China-Centre National de la Recherche Scientifique (National Center for Scientific Research)) Joint Research Project (No. 41611130163), National Natural Science Foundation of China (No. 41301215) and National Basic Research Program of China (No. 2012CB956100)

A 150-year Isotopic Record of Lead Deposition in Yancheng Coastal Wetland, China

BAO Kunshan1, SHEN Ji1, QUAN Guixiang2, LIU Fugang3   

  1. 1. State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China;
    2. School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China;
    3. School of Science, Qiqihar University, Qiqihar 161006, China
  • Received:2015-06-25 Revised:2015-10-18 Online:2016-12-27 Published:2016-11-05
  • Contact: BAO Kunshan.E-mail:ksbao@niglas.ac.cn E-mail:ksbao@niglas.ac.cn
  • Supported by:

    Under the auspices of Natural Science Foundation of Jiangsu Province, China (No. BK20131058), NSFC-CNRS (National Natural Science Foundation of China-Centre National de la Recherche Scientifique (National Center for Scientific Research)) Joint Research Project (No. 41611130163), National Natural Science Foundation of China (No. 41301215) and National Basic Research Program of China (No. 2012CB956100)

摘要:

Radioactive markers are useful in dating lead (Pb) deposition patterns from industrialization in sedimentary archives. As a well-known natural reserve in the world, Yancheng coastal wetland in Jiangsu Province is one of areas most sensitive to global sea level change and is located in the most developed and polluted region of China. Two cores were collected in Yancheng wetland in October 2013 and dated using 210Pb and 137Cs radiometric techniques. Sediments in both cores were sectioned into depth bands and examined systematically for dry bulk density, water content, magnetic susceptibility and grain-size. Multiple elements including Pb were also measured using inductively coupled plasma systems. Unsupported 210Pb activities decreased with depth in both of the two cores, and 210Pb chronologies were established (covering 150 years) using the constant rate of supply (CRS) model. The measured Pb contents ranged from 14.97 mg/kg to 29.40 mg/kg with average values of 17.17-22.79 mg/kg, and the Pb fluxes ranged from 41.70 mg/(m2·yr) to 172.70 mg/(m2·yr) with averages of 95.59-123.41 mg/(m2·yr). Temporal variations of Pb flux, enrichment factors and Pb isotopes show a gradual and continuous increase over time and clearly reflect increased emissions from anthropogenic activities in the region. The Pb isotopic compositions show that most of Pb deposition in Yancheng wetland is input from natural sources by water flows and has the same levels of Pb as in the surface sediment of the Yangtze River and the Pacific mineral aerosol. We also stress the anthropogenic Pb contribution in Yangcheng wetland sediment and the reason of our Pb isotopes not showing anthropogenic signature is likely the instability of anthropogenic Pb in high Fe/Mn oxide conditions. Therefore, more attention should be paid to current local pollution problems, and society should take action to seek a balance between economic development and environmental protection.

关键词: coastal wetland, Pb deposition rate, Pb isotope, 210Pb dating, metal pollution

Abstract:

Radioactive markers are useful in dating lead (Pb) deposition patterns from industrialization in sedimentary archives. As a well-known natural reserve in the world, Yancheng coastal wetland in Jiangsu Province is one of areas most sensitive to global sea level change and is located in the most developed and polluted region of China. Two cores were collected in Yancheng wetland in October 2013 and dated using 210Pb and 137Cs radiometric techniques. Sediments in both cores were sectioned into depth bands and examined systematically for dry bulk density, water content, magnetic susceptibility and grain-size. Multiple elements including Pb were also measured using inductively coupled plasma systems. Unsupported 210Pb activities decreased with depth in both of the two cores, and 210Pb chronologies were established (covering 150 years) using the constant rate of supply (CRS) model. The measured Pb contents ranged from 14.97 mg/kg to 29.40 mg/kg with average values of 17.17-22.79 mg/kg, and the Pb fluxes ranged from 41.70 mg/(m2·yr) to 172.70 mg/(m2·yr) with averages of 95.59-123.41 mg/(m2·yr). Temporal variations of Pb flux, enrichment factors and Pb isotopes show a gradual and continuous increase over time and clearly reflect increased emissions from anthropogenic activities in the region. The Pb isotopic compositions show that most of Pb deposition in Yancheng wetland is input from natural sources by water flows and has the same levels of Pb as in the surface sediment of the Yangtze River and the Pacific mineral aerosol. We also stress the anthropogenic Pb contribution in Yangcheng wetland sediment and the reason of our Pb isotopes not showing anthropogenic signature is likely the instability of anthropogenic Pb in high Fe/Mn oxide conditions. Therefore, more attention should be paid to current local pollution problems, and society should take action to seek a balance between economic development and environmental protection.

Key words: coastal wetland, Pb deposition rate, Pb isotope, 210Pb dating, metal pollution