Kim Hyuck Soo, Kim Kwon-Rae, Kim Won-Il, Owens Gary, Kim Kye-Hoon
Division of Chemical Safety, Department of Agro-Food Safety, National Institute of Agricultural Sciences, Wanju, 55365, Korea.
Department of Agronomy and Medicinal Plant Resources, Gyeongnam National University of Science and Technology, Jinju, 52725, Korea.
Arch Environ Contam Toxicol. 2017 Feb;72(2):260-268. doi: 10.1007/s00244-016-0344-y. Epub 2016 Dec 20.
The urban agricultural (UA) environment near active roadways can be degraded by traffic-related particles (i.e., exhaust gases and road dust), which may contain heavy metals. The current study investigated changes in heavy-metal [cadmium (Cd), copper (Cu), chromium (Cr) nickel (Ni), lead (Pb) and zinc (Zn)] concentrations in soils located near highly trafficked roads in Korea and the subsequent uptake of these metals by Chinese cabbage. Heavy-metal plant concentrations were determined in both washed and unwashed plant leaves to determine whether foliar deposition played any role in plant metal uptake. Soil concentrations of Cd, Cu, Pb, and Zn were all lower than the Korean standard soil limits and showed no significant influence from road traffic. In contrast, both Ni and Cr concentrations in soils collected within 10 m of the road were 4 and 5 times greater, respectively, than those in soils collected 70 m from the road. Heavy-metal concentrations in unwashed Chinese cabbage leaf collected at 5 m from the road were consistently greater than those of washed leaf samples, thus indicating the deposition of traffic-related particles on the plant surface. With the exception of Cu, all heavy-metal concentration in washed plant samples collected at 5 m also showed greater accumulation compared with samples collected further away. This was mainly attributed to increased total soil heavy-metal concentrations and increased metal phytoavailability induced by decreases in soil pH near the road. However, overall heavy-metal soil concentrations were well lower than the allowable concentrations, and the levels observed in plants collected in this study were considered not to currently pose a significant risk to human health. However, some traffic-related heavy metals, in particular Cr and Ni, were being accumulated in the roadside UA environment, which may warrant some caution regarding the environment and/or health issues in the future.
靠近繁忙道路的都市农业（UA）环境可能会因交通相关颗粒物（即废气和道路灰尘）而退化，这些颗粒物可能含有重金属。本研究调查了韩国交通繁忙道路附近土壤中重金属[镉（Cd）、铜（Cu）、铬（Cr）、镍（Ni）、铅（Pb）和锌（Zn）]浓度的变化，以及随后大白菜对这些金属的吸收情况。通过测定清洗和未清洗的植物叶片中的重金属含量，以确定叶面沉积是否在植物对金属的吸收中发挥作用。土壤中Cd、Cu、Pb和Zn的浓度均低于韩国标准土壤限值，且未显示出道路交通的显著影响。相比之下，在距离道路10米内采集的土壤中，Ni和Cr的浓度分别比距离道路70米处采集的土壤高4倍和5倍。在距离道路5米处采集的未清洗大白菜叶片中的重金属浓度始终高于清洗后的叶片样本，这表明交通相关颗粒物沉积在植物表面。除Cu外，在距离道路5米处采集的清洗后植物样本中的所有重金属浓度与更远距离采集的样本相比也显示出更高的积累。这主要归因于道路附近土壤pH值降低导致土壤中总重金属浓度增加以及金属植物有效性增加。然而，土壤中重金属的总体浓度远低于允许浓度，本研究中采集的植物中观察到的水平目前被认为不会对人类健康构成重大风险。然而，一些与交通相关的重金属，特别是Cr和Ni，正在路边的都市农业环境中积累，这可能需要在未来对环境和/或健康问题保持一定的谨慎。
