�Ա���ij�����Ӵ�����������ũ��������Ϊ�о����󣬲��õ��ۻ�ָ������DZ����̬Σ��ָ������������Cd ��Ni ����Ⱦ״�����з������ۡ��������������ұ�����Ĵ��Ӵ����������������� Cd ��Ni ��Ⱦ���أ�������������������ֵ; �Ӵ��������ؽ��������̶�ΪCd �� Ni������Cd �����̶ȴ�5 ����Ϊ����Ⱦ���Ե�����������ֵ��Ϊ�α�ֵ�������ۣ��ú��������ضȵ�DZ����̬Σ���̶ȣ��ؽ�������̬Σ��˳��ΪCd �� Ni��

For investigation of the risk assessment of Cd and Ni pollution in soil��the authors used geo-accumulation index and potential ecological risk index methods��taking the soils in riverbed and farmland of one river in North China as an example�� The results showed that the soils from riverbed and farmland near waste smelting center were severely polluted by Cd and Ni��which were higher than the local background soil value�� The enrichment degree of heavy metals in riverbed was Cd �� Ni��and the Cd reached grade 5 ( heavy pollution degree) �� Compared with the local soil background value��the concentration of heavy metals in the river showed serious ecological risk�� and the order of potential ecological risk of the two heavy metals was Cd �� Ni��