佛山市禅城区蔬菜重金属污染现状及对人体健康风险分析

目的了解佛山市禅城区居民食用蔬菜重金属的污染状况，评价重金属经蔬菜途径摄入的健康风险。方法按照均匀分散多点的原则随机采集佛山市禅城区城郊4个主要种植地及市区内4个主要市场售卖的根茎、瓜果、叶菜3大类别73份蔬菜，对样品的锌（zn）、铜（Cu）、镉（cd）、铅（Pb）、铬（Cr）5种重金属元素含量进行测定。采用单因子污染和尼梅罗综合污染评价指数法评价蔬菜重金属污染状况，采用暴露剂量一反应外推法对蔬菜重金属进行健康风险评价。结果所抽取的蔬菜样品中有46．6％（34／73）的蔬菜重金属含量超标，Ph和cr超标率分别为32．9％（24／73）和19．2％（14／73），2种金属同时超标的有4份，其余金属无超标。根茎类和瓜果类的综合污染指数分别为1．27及1．06，属轻度污染，主要受污染的品种为马铃薯、芹菜、丝瓜、茄瓜；叶菜类的综合污染指数为0．65，属安全级别；蔬菜中Cr、Cd、Ph、zn、cu的年平均个人摄入健康风险评价结果分别为4．43×10^-6、4．44×10^-6、7．40×10^-8、8．18×10^-9、1．02×10^-7，联合作用评价结果为4．48×10^-4，高于美国环保局与国际放射防护委员会分别推荐的标准。结论佛山市禅城区居民经蔬菜途径摄入重金属对人体具有一定潜在的健康风险，其风险主要来自化学致癌物Cr。应加强对蔬菜从种植至市场各环节监督和管理，确保人们的饮食安全。

Contents of heavy metals in vegetables and their potential risks to human health in Chancheng District, Foshan City

Objective To investigate the heavy metal pollution condition in vegetables in Chancheng District in Foshan City and to assess its human health risk. Methods Adopting uniform stratified random sampling, 73 samples of 3 kinds of vegetables including root, fruit, and leaf vegetables were collected from 4 planting sites and 4 markets of Chancheng District in Foshan City. The contents of zinc （Zn）, copper （Cu）, cadmium （Cd）, lead （Pb）, and chromium （Cr） in the samples were detected. Single factor contaminant index and the Nemerow synthetical pollution index method were adopted to evaluate the condition of heavy metal pollution in vegetables, and exposure dose - response extrapolation was used to assess the potential risk to human health. Results The contents of heavy metals in 46.6% （ 34/ 73） of the samples were higher than the permitted level. Pb and Cr were the main pollution elements in vegetables in the district, and the standard - exceeding rates were 32.9% （ 24/73 ） and 19.2% （ 14/73 ）. Contents of both Pb and Cr exceeded the standard in 4 samples simultaneously. The synthetical pollution indexes of root and fruit vegetables were 1.27 and 1.06, respectively, as light pollution. The potato, celery, loofah, and aubergine were the main polluted vegetables. The synthetical pollution index of leaf vegetables was O. 65, within the range of safety level. The individual health risk assessments of heavy metal pollution were 4.43 × 10 ^-4 （ Cr）, 4.44 × 10 ^-6 （ Cd）, 7.40 ×10 ^-8 （ Pb）, 8.18 × 10^ -9 （ Zn）, and 1.02 ×10^ 7（Cu）. The synthetical assessment was 4.48 × 10^-4, higher than the standard of US EPA＆ICRP. Conclusion In Chancheng District, more attention should be paid to potential health risks from heavy metals in vegetables. The risks mainly caused by Cr, the chemical carcinogen. We must strengthen the surveillance and management of the vegetable planters and marketing links to ensure food safety.