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[Evolvement and pollution of heavy metals in core sediments from Yamenqi Lake in Lianhuan Lake, China].

One sediment core was obtained from the center of Yamenqi Lake at the Songnen Plain in eastern China in August 2010 using a gravity corer. The sediment samples were digested using HNO3-HClO4-HF. Concentrations of the metals Cr, Cu, Mn, Ni, Fe, Pb, Zn, Cd, Al, Ba, Ca, K, Li, Mg, Na and Sr were determined using inductively coupled plasma-mass spectrometry (ICP-MS). With the dating approach, the characteristics and polluted history of heavy metals in lake sediments were determined. The heavy metal pollution of sediment was discussed based on the enrichment factor. The results are listed as following:(1) the contents of all elements had a smooth variation trend before 1950,and fluctuated severely from 1950 to 1990. The contents of Mn, Zn, Cd, Pb, Fe, Ni, Cr, Cu, Ca, Li and Sr increased obviously since 1990. (2) Mn, Zn, Pb and Cd showed light contamination degree. Contents of Ni, Cr and Cu were below the contamination level.