河南省大气重金属沉降高风险区蔬菜重金属含量及健康风险评估

Heavy metal concentrations and health risk assessment of vegetables in the high-risk area of atmospheric deposition in Henan Province

【目的】我们研究了大气重金属沉降高风险区菜地重金属的污染状况及污染来源,评价了研究区种植的蔬菜对不同人群(男性、女性、成人和青少年)产生的健康风险,并筛选了低累积重金属的蔬菜类型。【方法】在河南省大气重金属沉降风险高的蔬菜产区进行调查。分别采集设施栽培和露地条件下种植的叶类(青油菜、青菜、香菜)、葱蒜类(大蒜)、茄科类(茄子、辣椒、番茄)、瓜果类(苦瓜、黄瓜)、豆类(长角豆、四季豆)和块根类(萝卜)蔬菜样品,分析了蔬菜可食用部位Cd、Pb含量及富集能力,讨论了其主要的污染来源,并利用Monte Carlo模拟,对不同种类蔬菜可食用部位进行概率非致癌健康风险评价。【结果】设施栽培和露地条件下,蔬菜可食用部位Cd的富集系数均高于Pb。不同类别的蔬菜对重金属的吸收能力存在明显差异,瓜果类蔬菜为Cd、Pb低累积蔬菜,设施栽培条件下瓜果类蔬菜可食用部位积累的Cd、Pb含量最低,Cd、Pb含量分别为0.020、0.036(黄瓜)和0.008、0.055(苦瓜)mg/kg,低于食品重金属污染限值。对比设施栽培和露地条件下种植的蔬菜可食用部位的污染程度发现,露地条件下蔬菜Cd、Pb的污染程度更高,大部分叶类蔬菜和葱蒜类蔬菜为重度污染,其中青油菜Cd内梅罗综合污染指数(P_(N))达到10.26,P_(N)(Pb)达到了10.00。概率风险评价结果表明,不同人群摄入Cd、Pb污染蔬菜产生的复合非致癌健康风险差别不大,其中摄入瓜果类和块根类蔬菜对人体没有明显的负面影响,尤其是瓜果类蔬菜,设施栽培下,成年男性摄入苦瓜产生的总目标危险系数的P75(第75百分位点)仅为0.120。【结论】不同类型蔬菜的Cd、Pb富集能力差异显著,叶类蔬菜对Cd、Pb富集能力最强,瓜果类较弱,尤其是苦瓜。污染区设施栽培的瓜果和豆类蔬菜可安全食用。大气沉降是蔬菜Pb污染的重要来源之一,建议在大气重金属沉降高风险区进行设施栽培,选择低积累Cd、Pb的瓜果类蔬菜,降低重金属对人体健康产生的风险。

【Objectives】We studied the heavy metal pollution status,health risk,and the sources of cadmium(Cd)and lead(Pb)in vegetables surrounding the high-risk area of atmospheric heavy metal deposition in Jiyuan City,Henan Province.We aimed to scientifically evaluate the health risks caused by vegetable intake among different people(male,female,adolescent and adult)and to select the varieties with relatively low heavy metal concentrations.【Methods】The concentrations and bio-enrichment capacity of cadmium(Cd)and lead(Pb)of edible parts in different vegetables were determined and assessed under greenhouse and open-field cultivations in the study area.Further,we used Monte Carlo simulation to evaluate the probabilistic health risk of the edible parts of different vegetable varieties,including leafy(Brassica chinensis L.,Brassica rapa var.chinensis(Linnaeus)Kitamura,Coriandrum sativum L.),onion and garlic(Allium sativum L.),eggplant(Solanum melongena L.,Capsicum annuum L.,Lycopersicon esculentum L.),melon and fruit(Momordica charantia L.,Cucumis sativus L.),bean(Vigna unguiculata,Phaseolus vulgaris L.)and tuber(Raphanus sativus L.).【Results】The bioconcentration factors of cadmium(Cd)in the edible part of vegetables under greenhouse and open-field cultivations were higher than lead(Pb)due to the higher activity of cadmium(Cd)in the soil.There was variation in the capability of the vegetable varieties to absorb heavy metals.Cd and Pb concentrations in the edible part of vegetables were 0.020 and 0.036(Cucumis sativus L.)and 0.008 and 0.055(Momordica charantia L.)mg/kg,respectively,which were all below the limits for heavy metal concentrations.By comparing the pollution rate of the edible parts of the vegetables under greenhouse and open-field cultivations,we found that cadmium(Cd)and lead(Pb)pollution degrees were higher in vegetables under open-field conditions than in greenhouse.Most leafy vegetables were seriously polluted,especially green rape.The comprehensive pollution index(P_(N))of cadmium(Cd)and P_(N)(Pb)reached 10.26 and 10.00 under open-field conditions.According to the probabilistic health risk assessment results,there was little difference between male and female,adolescent and adults,due to the intake of cadmium(Cd)and lead(Pb)contaminated vegetables.The intake of melon and fruit,and tuber vegetables had no obvious negative effect on the human body,especially melon and fruit vegetables.The P75(the 75th percentile of the probability distribution of total target hazard quotient)compound health risk caused by the intake of bitter gourd in adult males in greenhouse was 0.120.【Conclusions】Vegetable varieties have quite different Cd and Pb accumulation capacities;leafy vegetables are easy to accumulate Cd and Pb,while melons and fruit vegetables are weak to accumulate,especially bitter gourd.Atmospheric deposition is one of the important sources of lead(Pb)pollution in vegetables.Thus,using a vegetable facility is recommended for melon cultivation,with a low accumulation of heavy metals in the high-risk atmospheric heavy metal deposition area.This has the potential to reduce the risk of heavy metals to human health.