Evaluation on the Heavy Metal Pollution in the Soil of Agricultural Land in Changtai District

In order to clarify the pollutionre situation of heavy metal in agricultural land in Changtai District of Zhangzhou City, and to assess its risk, 71 soil samples of agricultural land in Changtai District were collected to measure the contents of 8 heavy metals such as Cd, Pb, Cr, Cu, Zn, Ni, As and Hg in the soil in 2020. The risk assessment of pollution was carried out by using the methods of single pollution index, Nemerow comprehensive pollution index and geo-accumulation index. The results showed that the average single pollution index of 8 heavy metals in 71 monitoring areas was less than 1, but the single pollution index of some heavy metals was greater than 1 in 20 monitoring areas. The average Nemerow composite index was 0.66, and the average pollution degree was Ⅰ, but the pollution degree of 7 monitoring areas reached Ⅲ. The average geo-accumulation index was 0.40, and the average pollution degree was 1, but some heavy metals were accumulated in 66 monitoring areas. In general, the contents of 8 heavy metals in the soil of agricultural land in Changtai District were not higher than the screening values specified by the standard, and the contents of heavy metals in some monitoring areas have exceeded the screening value of soil pollution risk. The main pollution elements included Cd, Pb and Hg. Therefore, some active and effective countermeasures should be taken in time to avoid affecting the agricultural ecology and the quality and safety of agricultural products.