湛江地区农业土壤与作物砷含量及食用安全研究

Arsenic concentrations in farming land soils and crops of Zhanjiang region and edible safety

为了解湛江地区农业土壤及主要作物(可食用部分)中砷的含量和分布特征,共采集了106个土壤表层样品和43个农作物样品(包括蔬菜、水果、甘蔗和稻谷),并评价了农作物食用的安全风险。结果表明,湛江地区农业土壤中砷平均质量比为4.04 mg/kg,符合国家土壤1级标准(GB 15618—1995)的样品占98.1%,与国内外不同地区土壤砷平均含量相比,湛江地区土壤中砷平均含量相对较低。湛江地区各区域土壤受砷污染程度大小依此为:雷州、廉江、霞山、赤坎、徐闻、麻章、坡头、遂溪、吴川;4种主要土壤利用类型受砷污染程度大小依此为:水田、果园土、甘蔗地、菜地。湛江地区种植的主要农作物蔬菜、水果(含甘蔗)和稻谷可食部分砷平均质量比总体较低,分别为0.470×10^(-1)mg/kg、0.440×10(-1)mg/kg和0.179 mg/kg,均符合我国有关蔬菜、水果及粮食的卫生标准(GB 18406—2001),与我国土壤砷清洁地区的统计数据相当。湛江地区蔬菜、稻谷和水果3大类作物可食部分通过"土壤—植物—人体"途径年平均摄入量为39.45mg/(人·a),约占允许摄取限值(547.50 mg/(人·a))的7.2%,可见,食用湛江地区出产的蔬菜、水果和稻谷等农产品砷的安全风险不大。

The paper has done a detailed investigation and analysis of the arsenic concentrations in the farming land soils, in the crops and edible products in Zhanjiang region. As is known, Zhanjiang is situated at the Leizhou Peninsula, the southmost tip of China's Mainland. Traditionally, it is a high-yield agricultural region, however, the farm land has been found contaminated by residues of many kinds of industrial production. And, arsenic content happens to be one of such contaminants. In order to find out the arsenic content and its distribution feature in the farm soil and the main crops （edible part）, we have gathered 106 farm soil surface layer samples and 43 crop samples （including vegetables, fruit, sugar cane and rice）, and examined the crop edible security problem. The results of our research indicate： the average arsenic content in Zhanjiang farm soil is 4.04 mg/kg and 98.1% of the samples, which conform to the national soil primary standard （GB 15618-1995）. When comparing the average arsenic content in different local soils of the corresponding domestic and foreign regions, the average arsenic content in Zhanjiang is relatively low. When comparing various regions in Zhanjiang for their arsenic pollution degree, the pollution order shows the following order： Leizhou 〉 Lianjiang 〉 Xiashan 〉 Chikan 〉 Xuwen 〉 Mazhang 〉 Potou 〉 Suixi 〉 Wuchuan. If four kinds of main soil are compared for their arsenic concentrations, the order stands： paddy field 〉 garden mold 〉 sugar cane 〉 vegetable plot. Speaking of the region＇s main crops, vegetables, fruit （including sugar cane） and rice （edible part） can be said relatively lower polluted with arsenic content, which account for 0.470 ×10^-1 mg/kg, 0.440×10^-1 mg/kg and 0.179 mg/kg respectively. This also eomes in conformity with our state sanitation standard （GB 18406-2001 ） and match with the national soil arsenic dean region statistical data. The annual mean intake of the three head crops of Zhanjiang, that is, vegetables, rice and fruit （edible part）, is 38.86 mg/（man-year） through inspecting soil plant - human body for the content level, roughly about 7.1 percent of the reference dose （547.50 mg/（man-year））. Thus, it can be said that the security risk of arsenic from Zhanjiang＇ s edible products, that is, vegetables, fruit and rice and so on, remains meek.