Ecological health risk assessment of soil heavy metals in eastern Yinan County, Shandong Province

This paper is the result of soil and agricultural geological survey engineering.

Objective The east of Yinan County is the representative of Shandong Province with developed mining and agriculture in China. It is of great significance for environmental protection to control the local soil heavy metal pollution and its ecological health risks.

Methods This study systematically investigated and analyzed 4779 surface soil samples, obtained the latest distribution data of Hg, Cd, Cr, Ni, As, Cu, Pb, Zn, and evaluated the ecological health risks and related problems by geoaccumulation index method, potential ecological hazard index method and health risk assessment model.

Results (1) The mean content of each heavy metal mentioned above is roughly equivalent to the soil background value in Linyi City, but the Hg content is slightly high and its coefficient of variation is the largest, indicating that Hg in local soil is significantly affected by human activities. Compared with the risk screening values for soil contamination of agricultural land in China, Cu, Cr and Ni are the main elements exceeding the standard, the As, Cd, Cu and Pb contents are many times of the standard, and all of them may cause ecological health hazards. (2) According to the values of geoaccumulation index, the soil in this area is generally pollution-free, and the pollution of Hg and Cu was slightly stronger than that of the other six elements. (3) In terms of ecological risk, Hg and Cd are the main ecological risk elements, followed by As and Cu. The high ecological risk area includes three zones: the southeast of Tongjing Town, the area around Jinchang Village at the northwest of Jiehu Town, and the main urban area in the west of the county town. (4) In terms of human health risks, heavy metals have no non-carcinogenic risks and carcinogenic risks for adults, but they have non-carcinogenic risk and carcinogenic risk for children in few areas. Cr and As are the main non-carcinogenic risk elements, and As has the highest carcinogenic risk.

Conclusions The soil quality is generally good in the eastern Yinan County. However, the southeast of Tongjing Town, the area around Jinchang Village at the northwest of Jiehu Town and the main urban area in the west of the county town are high ecological risk areas. Hg, Cr and As are the main elements with ecological health risks.