Key Laboratory of Geographic Information Science, Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, China.
Key Laboratory of Geographic Information Science, Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, China.
Sci Total Environ. 2018 Apr 1;619-620:1349-1357. doi: 10.1016/j.scitotenv.2017.11.177. Epub 2017 Nov 23.
Vegetable fields have a high risk of heavy metal contamination from pollution sources in suburban and industrial areas of cities. Eighty-seven soil samples, 106 leafy vegetables and 48 road dust samples were collected from industrial areas of Shanghai, China. We studied the levels of heavy metals, health risk through consumption of leafy vegetables, and sources of Pb in soils, road dust and leafy vegetables. Soil Cd, Zn, Pb, Cu, Hg and As concentrations exceeded the soil background values in 73.6%, 97.7%, 52.3%, 37.8%, 95.1% and 20.2% soil samples, respectively, but were below the criteria for agricultural soil in China, with the exception of Hg. The concentrations of Cd, Zn, Pb, Cu and As in road dust were significantly higher than concentrations in soils, while Hg concentration in road dust was lower. Cd, Zn, Pb, Hg and Cu concentrations in soils and Zn, Pb and Cu concentrations in road dust were greatest near the municipal solid waste incineration power plant. Heavy metal concentrations in the edible tissues of vegetables were not correlated with their total values in soils and varied among vegetable species. The trends in transfer factors (TFs) in different vegetables were Cd>Zn>Cu>As>Hg>Pb. There was low health risk from heavy metal exposure by consumption of vegetables based on Hazard Quotients (HQ): As was the major contributor to HQ, followed by Cd and Pb. Parent material of the Yangtze River Estuary was the major source of Pb in soils, while coal-fired, stationary industrial emissions and municipal waste incineration emissions were the major sources of Pb in dust and vegetables based on use of the lead isotopic tracing method. Accumulation of Pb in leafy vegetables was through foliar uptake and directly related to atmospheric Pb.
蔬菜地受到城市郊区和工业区污染的影响，存在较高的重金属污染风险。本研究采集了中国上海市工业区的 87 个土壤样本、106 份叶菜类蔬菜和 48 份道路灰尘样本，研究了土壤、道路灰尘和叶菜类蔬菜中重金属的含量、通过食用叶菜类蔬菜摄入重金属的健康风险以及 Pb 的来源。土壤中 Cd、Zn、Pb、Cu、Hg 和 As 的浓度分别有 73.6%、97.7%、52.3%、37.8%、95.1%和 20.2%的样本超过土壤背景值，但除了 Hg 之外，所有样本的浓度均低于中国农业土壤标准。道路灰尘中的 Cd、Zn、Pb、Cu 和 As 浓度明显高于土壤中的浓度，而 Hg 浓度则较低。临近城市生活垃圾焚烧发电厂的土壤和道路灰尘中 Cd、Zn、Pb、Hg 和 Cu 的浓度最大。蔬菜可食用部分中的重金属浓度与其在土壤中的总量没有相关性，且不同蔬菜种类之间的重金属浓度也存在差异。不同蔬菜的转移系数（TFs）的变化趋势为 Cd>Zn>Cu>As>Hg>Pb。根据危害商数（HQ），食用蔬菜导致的重金属暴露的健康风险较低：As 是 HQ 的主要贡献者，其次是 Cd 和 Pb。基于铅同位素示踪法，长江口母岩是土壤中 Pb 的主要来源，而燃煤、固定工业排放和城市垃圾焚烧排放则是灰尘和蔬菜中 Pb 的主要来源。叶菜类蔬菜中 Pb 的积累是通过叶面吸收，与大气 Pb 直接相关。
