| Concentrations of As, Hg, Pb, Cd in soils and herbal medicine samples from cultivated regions of Anguo City in Hebei Province were analyzed and assessed, and the bioconcentration factors of different herbal medicines were studied and discussed as well. The results showed that the average contents of As, Hg, Pb, Cd in soils from herbal medicine cultivated regions were 12.9, 0.036, 15.6, 0.118 mg·kg-1, respectively. Concentrations of heavy metals in soils were lower than classⅡof the soil environmental quality standard. When local soil background values of heavy metals were used as assessment standard, among the 16 cultivated regions the percentage of As, Hg, Pb, Cd belonging to lightly pollution class were 18.75%, 43.75%, 0%, 100%, respectively based on the single pollution index. And the Nemerow index results were between 1 and 2, which suggested the soils were at slight pollution level. However, when quality standard class Ⅱ was used, both the single pollution index and Nemerow index did not exceed 0.7, which means that soils investigated were generally safe for cultivation of Chinese herbal medicines. The assessment of heavy metals in herbal medicines showed that the pollution indices of most herbal samples (<95%) were lower then 1. Cd bioconcentration factors of Aster tataricus L. and Anemarrhena asphodeloides Bunge, Hg bioconcentration factors of Angelica dahurica (Fisch.ex Hoffm.)Benth.et Hook.f. and Glehnia littoralis F.Schmidt ex Miq. were above 1. Therefore, the accumulation characteristic of heavy metals in Chinese herbal medicines should be fully concerned when GAP base soil quality assessment was taken. |
