the predominance of aldrin and dieldrin suggested that the two OCPs were the main cancer risk factor in the shallow groundwater of TLR. In all the shallow groundwater samples of TLR, cancer risk from p, p′-DDD and p, p′-DDT in the shallow groundwater were lower than the acceptable risk level (1 × 10−6) recommended by US EPA for carcinogens, indicating the carcinogenic risk levels caused by them were acceptable.