Objective  In order to realize the safe utilization and control of heavy metal polluted farmland soil, the pollution status, source, spatial distribution characteristics and potential ecological risk of heavy metals are needed to research in paddy field soil of Eastern Hebei plain.

  Method  The contents of Cr, Ni, Cu, Zn, Cd, Pb, Hg and As in paddy soil (0-20 cm) were determined by taking the surface soil sample of paddy field (0-20 cm) collected in the field as the research object. Single factor pollution index method, Nemero comprehensive pollution index evaluation, principal component analysis, cluster analysis and other multivariate statistical analysis methods were used to calculate the degree of heavy metal pollution in regional soil, and the source of heavy metal pollution were further analyzed.

  Result  Taking the risk screening value in soil environmental quality-Standard for risk control of soil pollution on agricultural land (Trial) (GB 15618−2018) as the evaluation benchmark of heavy metal pollution, it is concluded that some areas of paddy soil in the study area are obviously threatened by pollution, from the perspective of single heavy metal element. Cd pollution could not be ignored, and its exceeding standard rate reached 23.2%, which is the main element of soil pollution in the region. From the spatial distribution of heavy metal elements in soil, the main areas of heavy metal pollution were in the middle and west of the research area, and the area with serious Cd pollution was mainly concentrated in the middle area. The results of source analysis of heavy metals showed that the soil pollution of paddy field in Eastern Hebei plain is mainly affected by human activities, followed by soil forming parent materials, in which Cr and Zn are mainly affected by soil forming parent materials, and Ni, Pb, Cu, Hg and As are mainly affected by soil forming parent materials and human activities, which belongs to common mixed pollution. Cd is obviously affected by human activities. Sewage irrigation, vehicle exhaust emissions and atmospheric deposition are the main factors leading to the increase of Cd content.

  Conclusion  The contents of heavy metals in paddy soil in the eastern Hebei plain exceeded screening values. Differentiated safety utilization and control measures should be taken according to the potential ecological risk and in combination with the sources of heavy metal pollution in soil.