山西省饮水型慢性砷中毒病区环境介质中砷暴露水平调查

目的 调查山西省饮水型慢性砷中毒病区环境介质水、土壤以及自产粮食、蔬菜中的砷含量,了解该病区外环境中砷暴露水平,为病区地方性砷中毒的防治提供科学依据.方法 在山西省山阴县饮水型慢性砷中毒病区,按照《地方性砷中毒诊断标准》(WS/T 211-2001)选择126个家庭共309人作为调查对象,入户采集饮用水、土壤、当地自产粮食(小米、黍子)和蔬菜(马铃薯).水砷和粮食砷采用电感耦合等离子体质谱联用仪(ICP-MS)检测,土壤和蔬菜通过原子荧光分光光度计(AFS)定量检测砷含量.按饮水含砷量分为5组(≤10,＞ 10～50,＞50 ～ 100,＞100～200,＞200 μg/L),以≤10 μg/L组作为参考值,分析水砷暴露与皮肤病变的关系.结果 在抽取的126份饮用水样品中,水砷范围为4.04～720.00 μg/L,中位数为87.75 μg/L,超标率为63.49％(80/126)；粮食砷浓度范围为0.16～4.58 mg/kg,中位数为0.66 mg/kg,超标率为98.73％(78/79)；土壤和蔬菜中砷含量范围分别为5.34～13.74 mg/kg和0～ 0.30 mg/kg.用标准参考人估算通过饮水、粮食、蔬菜每天摄入的无机砷量,并与世界卫生组织(WHO)规定无机砷最大日允许摄入量(MTDI)比较,粮食中总砷含量为0.17 mg/kg时无机砷的摄入量相当于水砷浓度为10μg/L时无机砷的摄入量.同时,分析水砷暴露与皮肤病变关联强度,组间比值比(OR)分别为3.219、9.001、56.127、97.734,呈递增趋势,地方性砷中毒皮肤病变发病危险性逐渐增加,进一步对水砷暴露水平与皮肤病变严重程度进行Spearman等级相关检验,r=0.501 (P＜0.05),水砷暴露与砷中毒的皮肤病变存在关联性且水砷暴露水平越高,皮肤病变程度越严重.结论 山西省山阴县饮水型慢性砷中毒病区饮用水、自产粮食砷含量偏高,而土壤和蔬菜砷含量不高.饮用高砷井水是导致慢性砷中毒的主要危险因素,通过饮食摄入的砷也不容忽视.

Level of aseninc in environmental media in water-born endemic arsenicosis area of Shanxi province

Objective To investigate the level of arsenic in environmental media and food stuffs including vegetables in water-born endemic arsenicosis area for provide a scientific basis for endemic arsenicosis of Shanxi province.Methods Samples of drinking water,soil,and glutinous broom corn,foxtail millet,and potato were collected from local families in water-born endemic arsenicosis area of Shanyin county,Shanxi province.According to “Diagnosis Standard for Endemic Arsenicosis” (WS/T 211-2001 ),totally 309 people from 126 families were choosen for the survey.The content of arsenic in drinking water,glutinous broom corn and foxtail millet was quantitatively determined by inductively coupled plasma mass spectrometry(ICP-MS).The level of arsenic in soil and potato was measured by atomic fluorescence spectrometer(AFS).The water arsenic concentrations were divided into five groups,≤10,＞ 10 - 50,＞ 50 - 100,＞ 100 - 200,and ＞ 200 μ g/L,analysis the relationship between water arsenic exposure and skin lesions.Result In this study,126 water samples were collected.Arsenic concentrations in drinking water were 4.04 - 720.00 μg/L,the median value was 87.75 μg/L,and the ratio of arsenic level higher than the Chinese standards for drinking water(50 μg/L) was 63.49％(80/126).The levels of arsenic in food were 0.16 - 4.58 mg/kg,the median value of arsenic in food was 0.66 mg/kg,and 98.73％(78/79) of arsenic exceeded 0.2 mg/kg.Arsenic concentrations in soil and vegetable were 5.34 - 13.74 mg/kg and 0 - 0.30 mg/kg,respectively.Predicted inorganic arsenic intake from food and vegetable was modeled with the equivalent intake from drinking water for a typical Chinese diet.Daily consumption of grain with a total arsenic level of 0.17 mg/kg would be equivalent to a drinking water arsenic level of 10 μg/L.Otherwise,adjusted with gender and age,symptoms of skin lesions correlated positively with water arsenic concentrations in all subjects.The OR values were 3.219,9.001,56.127,and 97.734 for each group,respectively.Rank correlation test using Chi-square test and Spearman correlation test showed that the severity of skin lesions was associated with the increasing of arsenic content in water(x2 =128.747,P ＜ 0.05; r =0.501,P ＜ 0.05).Conclusions Arsenic levels in both drinking water and food are high in water-born endemic arsenicosis area of Shanxi province,and in soil and vegetables are not high.Arsenic in drinking water has been considered as a main risk factor of skin lesions,and dietary intake of arsenic through foodstuff can not be ignored.