Acta Geographica Sinica ›› 2017, Vol. 72 ›› Issue (5): 892-905.doi: 10.11821/dlxb201705010

• Land Use and Environmental Change • Previous Articles     Next Articles

Heavy metal enrichment and pollution of historical cultural layers in Kaifeng City, Henan Province

Yanfang CHEN1(), Jianhua MA1,2(), Dexin LIU1, Lei GU1   

  1. 1. Institute of Natural Resources and Environment, Henan University, Kaifeng 475004, Henan, China
    2. Collaborative Innovation Center on Yellow River Civilization of Henan Province & Key Research Institute of Yellow River Civilization and Sustainable Development, Henan University, Kaifeng 475001, Henan, China;
  • Received:2016-09-26 Revised:2017-02-08 Online:2017-05-20 Published:2017-05-20
  • Supported by:
    National Natural Science Foundation of China, No.41171409;Major Project of the Key Research Base of Human Science, National Educational Ministry of China, No.12JJD790023;Joint Project of the Ministry of Education of China and Henan Province for Developing Henan University, No.SBGJ090101


Several dynasty palaces in Kaifeng City were buried by flood sediments of the Yellow River, forming the unique spectacle of city overlapping city, which were taken as excellent and rare samples to assess heavy metal enrichment and pollution of historical cultural layers. Three sedimentary cores with a length of 25 m were drilled in April, 2012, of which two were located in the urban area of Kaifeng City (ZKsz and ZKyz), and the other one was located in the western suburbs of the city (ZKjm). Each core was split into 10 cm intervals mostly, for a total of 657 soil samples. Concentrations of Pb, Cd, Cu, Zn, Ni, Cr and Co in samples were measured by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), while Hg and As were analyzed with Atomic Fluorescence Spectrometer (AFS). The dating frameworks of all the cultural layers in different dynasties were established according to AMS14C dates, archaeological explorations and historical documents. The results showed that six cultural layers were found in all the three sedimentary cores, including the Warring States, Song-Jin Dynasty, early Ming Dynasty, mid-Ming Dynasty, late Ming Dynasty and Qing Dynasty. Enrichment factors (EF) were calculated to assess the enrichment of heavy metals in cultural layers. Enrichment of most heavy metals occurred in the cultural layers, and Hg contributed to the highest enrichment level. Enrichment levels of Hg in the cultural layers of the two urban cores (ZKsz and ZKyz) before the early Ming Dynasty were from significant to extremely high. Pollution load index (PLI) was used to identify pollution levels of heavy metals in cultural layers. Most cultural layers showed slight to moderate pollution, while Song-Jin cultural layers of the two urban cores were considered as moderate pollution. Mercury was the main pollutant of the two urban cores while Cu, Pb and Zn had minor effects on the pollution, due to the wide use of cinnabar with high Hg contents in the history. As for the cultural layers of ZKjm core, Cd, Cr, Hg and Pb made more contributions to the pollution. The results also showed the positive linear relationships between metal PLI of cultural layers and their corresponding population densities. The decreasing PLI values from the early Ming to late Ming Dynasty were influenced probably by the frequent floods of the Yellow River.

Key words: Kaifeng City, cultural layer, heavy metal, enrichment factor, pollution assessment