摘要:工业化和城市化带来的重金属污染对环境质量、食品安全、人体健康及社会经济可持续发展构成严重威胁和挑战。为了掌握典型城市化区域蔬菜生产的重金属污染特征与食用健康风险，从而为快速城市化区域的农业实践提供依据，本研究选取珠三角电镀、染织等工业密集典型城市化区域的蔬菜和土壤为研究对象，通过采集蔬菜和表层土壤样品，使用单因子污染评价和内梅罗综合污染指数法对蔬菜样品中Cd、Ni、Cr、As、Pb 5种重金属进行污染评价，使用目标危害商数法进行健康风险评价。研究发现，该地区菜地土壤存在Cd污染。研究区蔬菜中重金属的富集吸收能力为Cd > Ni > Cr > As > Pb，叶菜类对Cd的富集最多，豆角类对Ni的富集较多。单因子污染评价结果显示蔬菜中重金属超标率按大小排序为Ni > Cr > Cd > Pb=As，Ni、Cr和Cd超标率分别为10.53%、2.63%和1.32%，Pb和As均未超标；综合污染指数的评价显示叶菜类样品处于轻度污染水平，豆角类处于中度污染水平，瓜类尚未受到重金属污染。健康风险评价结果表明，叶菜类和豆角类的综合目标危害商数（TTHQ）均大于1，长期食用叶菜类和豆角类会对健康造成影响，成人和儿童的综合目标危害商数排序均为叶菜类>豆角类>瓜类，儿童摄食蔬菜的重金属健康风险高于成人。总体来说，研究区蔬菜重金属健康风险基本处于可接受范围，但叶菜类Cd和豆角类Ni造成的健康风险需引起重视。
关键词:典型城市化区/
蔬菜/
重金属/
累积特征/
污染评价/
健康风险
Abstract:Heavy metal pollution-related problems due to industrialization and urbanization are of great concern, and they pose severe threats and challenges to environmental quality, food safety, human health, and sustainable socioeconomic development. This study examined vegetables and soils in areas with intensive electroplating and dyeing industries. Vegetable and soil samples were collected, and single-factor pollution assessment and the Nemero comprehensive pollution index were used to evaluate the pollution levels of five heavy metals, i.e., Cd, Ni, Cr, As, and Pb, in vegetable samples. Further, the target hazard quotient method was used to assess health risk. Pollution by Cd was found in the vegetable soil in the study area. Enrichment and absorptive capacity of heavy metals in vegetable samples in the study area were in this order:Cd > Ni > Cr > As > Pb. Leafy vegetables had the highest Cd enrichment, whereas beans had the highest Ni enrichment. Single-factor pollution assessment revealed that the over-standard rate of heavy metals in the vegetable samples was in this order:Ni > Cr > Cd > Pb=As; moreover, the over-standard rates of Ni, Cr, and Cd were 10.53%, 2.63%, and 1.32%, respectively, and the content of Pb and As in the vegetable samples did not exceed the standard content. Nemero evaluation of the samples revealed that leafy vegetables had a mild level of pollution, beans had a moderate level of pollution, and melons were not contaminated by heavy metals. Health risk assessment revealed that the comprehensive target hazard quotient (TTHQ) of leafy vegetables and beans was>1 and that the long-term consumption of leafy vegetables and beans in the study area would adversely affect health. The TTHQ for adults and children was as follows:leafy vegetables > beans > melons. The health risks posed by the intake of heavy metals in food were higher for children than for adults. In general, the health risks posed by heavy metals in vegetables in the study area were within the acceptable range, but the health risks posed by Cd in leafy vegetables and Ni in beans need serious consideration.
Key words:Typical urbanized area/
Vegetables/
Heavy metals/
Residual characteristics/
Pollution assessment/
Health risk
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