贵州铜仁汞矿区主要农产品重金属污染及其健康风险评估

Heavy metal pollution and health risk in major agricultural products in Tongren mercury mine area,Guizhou

在贵州省铜仁市汞矿区重要的粮油和蔬菜生产基地司前大坝,采集大米、蔬菜、鸡蛋、猪肉和鱼肉等农产品样品,分析了重金属Hg、Cd、Pb和Mn含量,利用单项污染指数和危害指数对农产品的重金属污染状况及其潜在的健康风险进行评估。结果表明,司前大坝农产品中Hg、Cd、Pb和Mn的平均质量比分别为大米9.53μg/kg、34.19μg/kg、33.16μg/kg、22 125μg/kg,蔬菜5.38μg/kg、24.76μg/kg、41.83μg/kg、2 299μg/kg,猪肉146.2μg/kg、8.32μg/kg、30.86μg/kg、2 757μg/kg,鱼肉155.5μg/kg、25.00μg/kg、16.66μg/kg、1 065μg/kg。鸡蛋中Hg和Mn的平均质量比分别为61.74μg/kg和71.33μg/kg,Cd和Pb质量比低于检出限。所有农产品Pb的污染指数小于1,没有受到Pb污染。但青菜、鸡蛋、猪肉和蒜苗Hg的单项污染指数分别为1.07、1.23、2.92和3.27,辣椒Cd的单项污染指数为1.29,表明青菜和鸡蛋受到Hg的轻度污染,猪肉受到Hg的中度污染,蒜苗受到Hg的重度污染,辣椒受到Cd的轻度污染。司前大坝居民经农产品摄入重金属的危害指数HI为3.26,当地居民长期食用这些农产品会对其健康造成不利影响。其中,大米的危害指数为2.14,占总危害指数的65.6%,是居民健康风险的主要来源。Mn和Hg的危害指数为1.57和1.03,分别占总危害指数的48.2%和31.6%,是影响居民健康的主要因素。

This study is aimed to make an assessment of the heavy metal pollution seriousness to be brought about for the farm produce from Siqian,a village located 20 km northeast to Wanshan mercury mine in Guizhou and the potential risk to local resident health as a result of consuming the grain food produced there. As a matter of fact,Siqian serves as the major agricultural production base for Tongren City of Guizhou. For its importance,we have managed to collect 82 farming produce samples from the village,including rice,vegetables,eggs,pork and fish. And,then,we have analyzed and determined the contents of Hg,Cd,Pb and Mn in the produce by means of an atomic fluorescence spectrometry（ AFS） and inductively coupled plasma-mass spectrometry（ ICP-MS）. Furthermore,the contents of the heavy metal pollutants have also been checked in the farming produce with the single pollution index method. All the above study measures have made us work out the target hazard quotient（ THQ）and the hazard index（ HI） so as to disclose the potential health risk to the local grain food consumers. The average mass ratios of Hg,Cd,Pb and Mn in the produce have been found equal to9. 53 μg/kg,34. 19 μg/kg,33. 16 μg/kg,22 125 μg/kg in rice,5. 38 μg/kg,24. 76 μg/kg,41. 83 μg/kg,2 299 μg/kg in vegetables,146. 2 μg/kg,8. 32 μg/kg,30. 86 μg/kg,2 757μg/kg in the pork,and 155. 5 μg/kg,25. 00 μg/kg,16. 66 μg/kg,1 065 μg/kg in fish,respectively. The mean mass ratios of Hg and Mn in the egg account for 61. 74 μg/kg and 71. 33 μg/kg,whereas the average contents of Cd and Pb in the egg stand below the detectable limits. On the other hand,in terms of the single pollution index,the farm produce has been found free from the pollution of Pb,whereas some other kinds of the produce have been found polluted at different levels by Hg and Cd. And,in terms of the pollution of Hg,the single pollution indices of Chinese cabbage,egg,pork and garlic sprout account for 1. 07,1. 23,2. 92 and 3. 27. Therefore,the Chinese cabbage and egg tend to be slightly contaminated,whereas pork suffers from a moderate contamination,with garlic sprout being heavily polluted. As for Cd,only pepper has been slightly polluted with an index of 1. 29,whereas the HI for dietary Hg,Cd,Pb and Mn intake has been found equal to 3. 26,indicating that all the abovementioned farm produce from Siqian may impose a potential health risk to the local consumers. Since rice used to be the main food resource with the potentially harmful element dietary intake,the total elements THQs as a result of consuming rice may be equal to 2. 36,accounting for 65. 6% to the HI. Besides,the total diet THQ of Mn and Hg may stand for 1. 57 and 1. 03,which takes about 48. 2% and 31. 6% to the HI. Thus,it can be concluded that Mn and Hg are the chief pollution components that contribute to the entire potential pollution exposure to the farm produce consumers.