Abstract:
In accordance with the Environmental Quality Standard for Soils(GB15618-1995) and the background value of heavy metals for soils of Yunnan Province, we analyzed concentrations of As, Cd, Pb and Zn in 561 paddy soil samples from 50 agricultural production areas in Gejiu City of Yunnan Province, and then assessed the pollution and ecological risk of these heavy metals.Results showed that average concentrations of As, Cd, Cr, Pb and Zn were 129, 1.6, 104, 212 and 249 mg·kg
-1, single factor pollution index of As, Cd, Cr, Pb and Zn were 4.31, 6.73, 0.44, 0.79 and 1.05, and comprehensive pollution index of all the heavy metals was 4.06, respectively; which implied the pollution of heavy metals was at severe level in agricultural production areas of Gejiu City, especially with a combined pollution of As and Cd.Moreover, the risk index of As and Cd in these areas were 70.2 and 218.2, with moderate and severe level, respectively; the potential total ecological risk index was 319.5, with a severe level in general.Therefore, the safety of agricultural production areas should attact the attention of the relevant departments in Gejiu City.