Resources & Environment·Plant Protection
Shuhua RU, Wanqiang XU, Ouya ZHAO, Shiyou SUN, Lei LIU, Guangmin XIAO, Limin HOU
In order to understand the characteristics and potential risks of heavy metals accumulation in farmland soils and agricultural products in typical areas of Hebei Province,soil samples (0—20 cm)and agricultural products were collected from metal smelting areas,sewage irrigation areas and vegetable areas,the contents of heavy metals Cr,Cd,Pb,As,Hg,Cu,Zn and soil pH were determined. The environmental quality of farmland soil in typical areas of Hebei Province was evaluated by the method of combining single-factor pollution index with nemerow comprehensive pollution index,the safety of agricultural products was evaluated. The results showed that the descending order of single pollution index of 7 heavy metals was Cd,Zn,Cu,As,Cr,Pb and Hg,and the single pollution index of Cd,Pb,Cu,Zn in some soil samples was more than 1.0,the environmental quality was above grade Ⅲ,and the rate of exceeding the standard of soil Cd was the highest (18.51%). Cd,Cu,Pb and Zn in the soils of the smelting area exceeded the standard,and the exceeding rate was 92.31%,69.23%,34.62% and 26.92%,respectively. The accumulation of Cd and Zn in the soil of sewage irrigation area was the most obvious,and the over-standard rate was 8.70%. The accumulation of Cd in vegetable soil was the most obvious,and the over-standard rate was 9.94%. Overall,the comprehensive pollution index of 7 heavy metals in farmland of Hebei Province was 0.64,and the soil environmental quality was in grade Ⅰ,which was clean. The soil environmental quality grades of smelting area,sewage irrigation area and vegetable area were in grade Ⅲ(light pollution),Grade Ⅰ(safety)and Grade Ⅰ(safety),respectively. According to the relevant food safety standards (NY 861—2004,GB2762—2022),the excess rates of Pb,Cd and Zn in wheat grains around the smelting area were 40.00%,40.00% and 60.00%,respectively. The excess rates of Zn,Pb and Cd in wheat grains were 57.45%,8.51% and 6.38%,respectively. The content of heavy metals in all vegetables in the vegetable area was not exceeding the standard,and the quality of vegetables is safe. Therefore,the soil environmental quality and the quality safety of agricultural products in smelting and sewage irrigation areas should be paid enough attention.