近几十年来,稻田重金属污染问题已引起广泛关注。然而,大多数关于稻田重金属污染的研究偏向于土壤和/或水稻植物,不考虑大气沉积。在这项研究中,大气沉降,水稻土,从三个功能区(靠近工厂的区域,沿着路边,和郊区)在长株潭,湖南省。污染特征,易位,并重新评估了重金属的健康风险。研究结果表明,研究区土壤中的Cd和As污染更为严重,点超标率达到70%和35.9%,分别。砷的最高浓度,Ni,Cd,在路边发现了大气沉积中的铅,1.42μg/m2/天,3.21μg/m2/天,0.34μg/m2/天,和8.28μg/m2/天,分别。在靠近工厂的地区,大气中的As和Ni沉积显示最低,而郊区的Cd和Pb浓度最低。此外,工厂附近地区水稻籽粒中Cd和Pb的积累明显高于其他地区。人体健康风险评估表明,在工厂附近的地区,大米摄入造成的健康风险最高,需要引起注意,这主要是由于Cd的积累,HQ值达到3.19。相关试验表明,大气沉降对水稻籽粒重金属富集具有积极作用。进一步的随机森林分析显示,大气沉降中重金属向叶片和贝壳的迁移是影响As,Cd,水稻籽粒中Ni和Mg的积累。因此,应重视大气沉降对稻田重金属积累的影响,以维护作物的生产安全。
In recent decades, the problem of heavy metal contamination in rice paddies has attracted widespread attention. However, most studies on heavy metal contamination in paddy fields are biased towards soil and/or rice plants, without taking atmospheric deposition into account. In this study, atmospheric deposition, paddy soil, and rice samples were collected from three functional areas (area proximity to factories, along the roadside, and suburban) in ChangZhuTan, Hunan Province. The pollution characterization, translocation, and health risk of heavy metals were reassessed. The findings revealed that Cd and As contamination in the study area\'s soils was more severe, with point exceedance rates reaching 70 % and 35.9 %, respectively. The highest concentrations of As, Ni, Cd, and Pb in atmospheric deposition were found along the roadside, with 1.42 μg/m2/day, 3.21 μg/m2/day, 0.34 μg/m2/day, and 8.28 μg/m2/day, respectively. In area proximity to factories, As and Ni in atmospheric deposition showed to be lowest, whereas Cd and Pb concentrations showed lowest in suburban areas. Furthermore, the accumulation of Cd and Pb in rice grains in regions proximity to factories was significantly higher than in other regions. The human health risk assessment indicated the health risk caused by rice intake in areas proximity to factories was the highest and requires attention, which was mainly due to Cd accumulation, with HQ value reached 3.19. Correlation tests indicate that atmospheric deposition has a positive effect on heavy metal enrichment in rice grains. Further Random Forest analysis revealed that the transport of heavy metals from atmospheric deposition to leaves and shells were important influencing factors for As, Cd, Ni and Mg accumulation in rice grain. Therefore, more attention should be paid to the effects of atmospheric deposition on the accumulation of heavy metals in paddy fields in order to maintain the production safety of crops.