| Popis: |
Certain heavy metal contaminated site is taken as the example to determine whether the four pollutants, namely As, Cr, Cr (VI) and Ni, exceed the screen levels of soil pollutants for health risk assessment of residential lands specified in Screening Levels for Soil Environmental Risk Assessment of Sites (DB11/T 811-2011) through sampling analysis. In allusion to the main exposure pathway of sensitive population, RBCA model is adopted to assess the health risk of this site, and the results show that the carcinogenic risks of Cr (VI) and As in the three layers of tested sample soils both exceed 10-6 with Cr (VI) and Ni in the first and second layers have larger non-carcinogenic quotient. At last, 10-6 and 1 are regarded as acceptable risk levels, then the RBCA model is used to adversely deduce the pollution remediation target values of the site, and the calculated results are compared with Grade A standards specified in the Assessment Standards for Soil Environmental Quality of Exhibition Lands (Provisional) (HJ350-2007). Then the background values of local soil environment for correction and finally the relatively rational soil pollution remediation target values have been obtained: Cr (VI): 2mg•kg-1, As: 20mg•kg-1, Ni: 50mg•kg-1, Cr: 190 mg•kg-1. |
