An integrated method of health risk assessment based on spatial interpolation and source apportionment

Soil heavy metals (SHMs) could cause environmental pollution, which had attracted great concern in China. In this study, a method was developed by integrating health risk assessment based on spatial interpolation and source apportionment (SSRA) to evaluate potential hazards of SHMs for human health. The optimized spatial interpolation provided global quality assurance for source apportionment, and quantified source contribution was introduced into health risk assessment. The six heavy metals of soil (Zn, Pb, Cd, Cr, As and Ni) from the electroplate factory in the southwest of Suzhou were investigated. The results of SSRA method were summarized as follows: (1) Ordinary kriging (OK) with R² and the slope (predicted value/observed value) closing 1 was more suitable for the spatial distribution of SHMs than inverse distance weighting (IDW). (2) Positive matrix factorization (PMF) showed better performance (R² closer to 1 and the suitable number of sources) than principal component analysis-multiple linear regressions (PCA-MLR). PMF extracted the accumulation of SHMs as traffic, natural, agricultural, atmosphere deposition and industrial sources. (3) The carcinogenic risks of As and Cr exceeded 1.0E-04, indicated that it would pose a potential risk to the human health. Moreover, higher total hazard index (THI)/carcinogenic risks (TCR) of source contribution was agriculture/industry, which accounted for 3.5E-01/2.6E-04, respectively. Control of agricultural and industrial sources could reduce hazard for residents. The integrated method of SSRA was reported, which could quantify the health risk of spatial related sources contribution and put forward competent environmental risk strategies for similar polluted area.