• 关键词：北京市  蔬菜  镉  健康风险  抗污染品种

• 基金项目：国家杰出青年基金项目(No.40325003);北京市自然科学基金重大项目(No.6990002)

• 宋波
• 1. 中国科学院地理科学与资源研究所环境修复研究中心, 北京 100101; 2. 中国科学院研究生院, 北京 100039

• 陈同斌
• 中国科学院地理科学与资源研究所环境修复研究中心, 北京 100101

• 郑袁明
• 中国科学院地理科学与资源研究所环境修复研究中心, 北京 100101

• 黄泽春
• 中国科学院地理科学与资源研究所环境修复研究中心, 北京 100101

• 郑国砥
• 中国科学院地理科学与资源研究所环境修复研究中心, 北京 100101

• 罗金发
• 中国科学院地理科学与资源研究所环境修复研究中心, 北京 100101

• 摘要：通过对北京市蔬菜和菜地土壤镉含量状况进行大规模调查,研究了蔬菜和土壤镉含量及其健康风险,并筛选出抗镉污染能力强的蔬菜品种.根据蔬菜的消费量同时兼顾品种多样性的原则,在北京市规模化蔬菜栽培基地(采集蔬菜及土壤样品)和蔬菜批发市场(蔬菜样品)共采集97种蔬菜363个样品和54个土壤样品.研究发现:北京市菜地土壤镉积累明显,其范围为0.091～0.971mg·kg^-1,其算术均值和Box-Cox均值分别为0.229和0.187mg·kg^-1,其中有两个样点土壤镉含量(0.971和0.886mg·kg^-1)超过《土壤环境质量标准》(GB15618-1995)中的二级标准(0.6mg·kg^-1);北京市蔬菜镉含量范围、算术均值和Box-Cox均值分别为0.1～101.4、12.8和10.0μg·kg^-1;叶菜类和根茎类蔬菜的镉平均含量显著高于瓜果类和特菜;北京市本地产蔬菜与市售外地产蔬菜的镉含量没有显著差异;裸露地蔬菜镉含量显著高于设施蔬菜;小白菜、辣椒、茄子、萝卜和大白菜镉富集系数较高,其抗镉污染能力较弱,而冬瓜、黄瓜、叶甜菜、大葱、云架豆、甘蓝、西红柿等镉富集系数较低,其抗镉污染能力较强.北京市居民每人从蔬菜中摄入镉的量为12.2μg·d^-1,蔬菜镉对北京市部分人群存在一定的潜在健康风险.

• Abstract：In order to assess the human health risk posed by elevated concentrations of cadmium in vegetables, and to identify pollution-tolerant vegetable varieties, a large scale survey of cadmium levels in soil and vegetables planted or sold in Beijing was conducted. Fifty-four soil samples were collected from gardens and fields used to grow vegetable plants. In addition, 97 varieties of 363 fresh vegetable samples were obtained from vegetable stalls, supermarkets and wholesale outlets. Cadmium concentrations were measured using graphite furnace atomic absorption spectrometry (GF-AAS). Cadmium concentrations in soils ranged from 0.091 to 0.971 mg·kg^-1, with arithmetic, geometric and Box-Cox means of 0.229, 0.201 and 0.187 mg·kg^-1, respectively. Compared with the background cadmium concentrations of soil from Beijing, there appeared to be a significant accumulation of cadmium in soil collected from fields that produce vegetables. Cadmium concentrations in the edible plant portions ranged from less than the analytical detection limit (0.1 μg·kg^-1 fresh weight) to 101.4 μg·kg^-1 fresh weight, with arithmetic, geometric and Box-Cox means of 12.8, 8.4 and 10.0 μg·kg^-1 fresh weight, respectively. In 98.3% of the samples, cadmium was less than the Tolerance Limit of Cadmium in Foods (TLCF) of 50 μg·kg^-1 fresh weight. The TLCF is the maximum permissible concentration of cadmium in vegetables that will be consumed by people. The highest level of cadmium detected in a vegetable plant was 101.4 μg·kg^-1, which was measured in a water shield (Brasenia schreberi) sample obtained from the Changping district of Beijing. Cadmium was detected at 61.6 and 50.8 μg·kg^-1 in two eggplant (Solanum sp.) samples, 58.0 g·kg^-1 in Youmaicai (Chinese lettuce) and 51.0 μg·kg^-1 in a sugarbeet sample. Only the eggplant samples exceeded the WHO/FAO and European Community (EC) cadmium standard of 50 μg·kg^-1 for vegetables other than leaves and rhizomes. The cadmium concentration in field-grown vegetables was significantly higher than the concentration of those planted in a greenhouse. Results of hierarchical cluster analysis on the cadmium bioconcentration factor (BCF) in vegetables indicated that the plants sampled could be separated into two groups based on BCF.Pakchoi (Brassica chinensis), Chinese cabbage (Brassica pekinensis), radish (Raphanus), chili (Capsicum annuum) and eggplant (Solanum sp.) had higher cadmium BCFs while cucumber (Cucumis sativus), wax gourd (Beninacasa hispida), spinach (Spinacia oleracea), beans round trellis (Vigna unguiculata), welsh onion (Allium fistulosum),tomato (Lycopersicon esculentum) and cabbage (Brassica caulorapa) had lower cadmium BCFs. The average ingestion rate of cadmium from vegetables was 12.2 μg/individual/day for people of Beijing. Consuming vegetables with elevated cadmium concentrations may pose a health risk to local residents, particularly the young, elderly, or ill.

• Key words：cadmium  Beijing  vegetables  soil  bioaccumulation  human health risk  pollutant-resistant plants

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