Health Risk Assessment of Soil Heavy Metals in the Urban-Rural Area of Lanzhou City, Gansu Province, China

Abstract

To investigate the health risks of typical soil heavy metals to surrounding residents of industrial land in the urban-rural area of Liuquan Town, Xigu District, Lanzhou City, China. The contents of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn were analyzed using an X-ray fluorescence spectrometer. Non-carcinogenic and carcinogenic risks of the heavy metals to children and adults were evaluated. Results showed higher soil Hg, Pb, and Zn contents in the study area than the corresponding background values of Gansu Province. The Hg pollution was the most serious, showing higher contents than the background water at 56.41% of the soil sampling sites. As, Cr, Cu, Ni, and Pb showed normal distributions, while Cd, Hg, and Zn exhibited skewed distributions. Hg and Cd showed the highest coefficients of variation of 0.966 and 0.548, respectively. Health risk evaluation results showed higher total non-carcinogenic risk (HI) and total carcinogenic risk (TCR) for children than those for adults by 5.411 and 2.156, respectively, indicating children are more susceptible to non-carcinogenic and carcinogenic risks. In addition, As, Cr, and Pb were the main contributors to the non-carcinogenic risk, while As and Cr were the main contributors to the carcinogenic risk.