广州市郊区蔬菜中铅的含量特征及其健康风险评估

对广州市郊区某蔬菜生产基地的蔬菜样品铅元素的含量进行分析测定,评价其污染程度,并评估人群经食用蔬菜摄入铅的健康风险。结果表明,蔬菜铅的平均含量为0.08mg·kg-1,超过《农产品安全质量无公害蔬菜安全要求》所规定铅的限量值（0.2mg·kg-1）的比率为12.9%。蔬菜铅的单项评价指数均小于1,辣椒除外（2.05）,这表明除个别蔬菜品种外,广州市郊区蔬菜铅的等级为安全。蔬菜铅含量表现为叶菜类〉瓜果类,与其他种类相比,叶菜类蔬菜对珠江三角洲地区人体健康造成的风险较大。据广东省不同地区、家庭经济收入水平每标准人经食用蔬菜日均铅摄入量（Daily intake,DI）均未超过FAO/WHO人均日摄入可允许限量标准（Provisional tolerable daily intake,PTDI）,铅的THQ（Target hazard quotients）靶标危害系数均小于1,表现为THQ城市=THQ高〉THQ中〉THQ低=THQ农村,这说明城市人群经蔬菜暴露途径摄入铅的潜在健康风险较高。

The Content Characters and Health Risk Assessment of Vegetable Lead in Guangzhou Suburbs,China

In order to evaluate pollution degree of lead in vegetables,and to assess the human health risks through vegetables for the general population,a large scale survey of lead levels in vegetables planted in Guangzhou suburbs was conducted.163 vegetable samples were collected from certain vegetable production base,and lead concentrations were measured using graphite furnace atomic absorption spectrophotomete（rGF-AAS）.Results showed that the average content of vegetable lead was 0.08 mg·kg-1 fresh weight,with 12.9% of tested samples above the Safety Requirements for Non-environmental Pollution Vegetable of 0.2 mg·kg-1 fresh weight.Single-factor contaminant index was utilized for assessment.It was found that the single-factor contaminant index of all vegetables lead were less than one except hot pepper（2.05）,indicating that the lead in vegetable in Guangzhou suburbs was safe.The concentrations of lead in vegetable decreased in the following order：leaf vegetablesfruit vegetables,dark vegetableslight vegetables,which implied that leaf vegetables were larger contribution than fruit vegetables to health risk for the general population in the Pearl River Delta.The average daily intakes（DI）of lead by per standard person in urban and rural were 21.6 and 18.7 μg·d-1,respectively and the DI of different family economical levels of Guangdong ranged from high to low were 22.1,20.2 and 18.3 μg·d-1,respectively,which belowed the provisional tolerable daily intake（PTDI）established by FAO/WHO.The health risks associated with lead were assessed based on the target hazard quotients（THQs）,which could be derived from concentrations of lead in vegetables consumed in the inhabitants.The THQs of vegetables lead were below 1,according to the different areas and the different levels of family economic income in Guangdong.Moreover,it showed that THQurban=THQhighTHQmediumTHQlow=THQrural,indicating the health risk via vegetable consumption in rural was relative low,more attentions should be paied to urban and high level of family economic incomes.