湛江市农业土壤与作物铬含量及其健康风险

Concentration of Chromium in Agricultural Soil and Crops and Their Healthy Risk

在湛江市采集了106个农业土壤表层样品和43个农作物样品,分析了土壤和农作物中铬的含量,研究铬的分布特征和富集能力,评价其健康风险。结果表明:土壤中铬平均含量为87.13mg/kg,超过国家土壤二级标准的样品占20.75%,徐闻、雷州等地超标较严重。湛江市种植面积及产量最大的4大类农作物蔬菜、水果、甘蔗和水稻铬平均含量介于0.014～0.160mg/kg之间,均符合我国《食品中铬限量卫生标准》(GB 14961-1994)。蔬菜类的芥菜铬的富集能力相对较强,青瓜、菜心、生菜等蔬菜品种和菠萝、香蕉、橙子、甘蔗等水果类铬的富集能力则较低;水稻铬的富集能力容易受土壤复合污染影响,富集系数介于0.0001～0.0048。依据中国营养学会推荐的RfD值和广东省居民平均食物消费结构进行计算,湛江市蔬菜、水稻和水果(含甘蔗)三大类作物通过土壤-植物-人体途径日平均摄入量为78.9μg/d,若考虑其它的摄入途径,农产品中的铬对人体潜在一定的健康风险。

In order to study distribution characteristics of Cr in soil and bioconcentration ability of Cr in crops, 106 topsoil samples and 43 crop samples were collected from 4 functional agriculture areas of Zhanjiang City, south China. Results indicated that average concentration of Cr in soil was 87.13mg/kg, with 20.75% samples beyond class II of national soil standard. Average concentration of Cr in vegetables, paddy rice, fruit and sugarcane ranged from 0.014 to 0.160mg/kg, which satisfied limited hygienic standard of Cr in foods. The bioconcentration ability of Cr in leaf musdard was relative strong, while that in vegetable variety including green cucumber, false pakchoi and salad as well as in fruit variety including pineap- ple, banana, orange and sugarcane was relative weak. Bioconcentration factors of Cr in paddy rice were 0.0001-0.0048, which were easily affected by composite pollution of soil. It was calculated that daily average intake of Cr in vegetable, paddy rice and fruit including sugarcane varieties by pathway to soil-plant-human being was 78.9μg/d. If considering other intake pathways, concentration of Cr in crops may lead to a little of healthy risk for human being.