Characteristics, spatiotemporal distribution, and risk assessment of Cu and Ni pollution in a farmland soil-corn system of arid oasis city in Northwest China

The rapid development of mining resources in the northwest oasis industrial and mining cities has brought many environmental problems. Previous research on heavy metals in cities in the Northwest Oasis mainly focused on the soil-wheat system, lacking research on the soil-corn system. As one of the main crops grown in the Northwest region, the pollution of heavy metals in corn grains is closely related to the physical health of the people in the Northwest region. The results show that the average content of Cu and Ni in the soil of the study area were 124.00 mg kg ^− 1 and 136.80 mg kg ^− 1 , respectively, which are both higher than the background value of the area. The content of various heavy metals varies among the various organs of corn, The contents of Cu and Ni were the highest in tassel. The spatial distribution characteristics of heavy metals show that Cu and Ni have similarities in spatial distribution and may have the same source. The average Bio-concentration and translocation factors of corn plants are Cu > Ni. The hazard quotient (HQ) value of both children and adults are less than 1, indicating that Cu and Ni have no significant health risks for both adults and children.