Historical record of trace elements input and risk in the shallow freshwater lake, North China

Approximately 80-year input of trace elements (Cr, Cu, Mn, Ni, Zn, Fe, and P) based on Pb-210 analysis in sediment cores was studied to assess the contamination status of these elements in the Baiyangdian Lake in China. The pollution concentration and enrichment factor, geoaccumulation index, and ecological risk index of these metals indicate that the degree of pollution and risk of these metals in the lake is higher in the upper layers (0-5 cm) and in recent years (1997-2012), but still at a moderate level. Among these metals, Cr and Ni may cause slight adverse biological effects in the area. Although the study indicated that the lake was not significantly affected by anthropogenic activities, a good logarithmic relationship (R-2 >= 0.85) between the ecological risk index and gross domestic product per capita in Baoding City, China, during 1943-2012 confirmed the effect of increasing human activity on the lake. The correlation and principal component analyses indicated that Cr, Zn, Mn, and Fe mainly originated from natural input with weathering and erosion of rocks and soil parent materials; however, Cu, Ni, total organic carbon, and P mainly originated from anthropogenic activities such as agriculture, industry, and sewage effluents. (C) 2015 Elsevier B.V. All rights reserved.