内蒙古自治区河套平原砷中毒高发区作物中砷的检测及健康风险评价

为了研究地方性砷中毒高发区作物中砷含量及其对人体健康的威胁,在内蒙古自治区河套平原4个自然村采集了72个谷物蔬菜水果、81份人体尿样和8个自来水样品。用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)分析测定采集的样品中各形态砷及其含量;用ICP-MS分析测定消解后的作物样品中砷总量。结果表明,自来水中总砷含量均小于1.0μg·L-1。尿液样品中总砷含量为4.50～319μg·L-1(平均值为56.9μg·L-1),二甲基砷(DMA)是尿砷的主要形态(>70%)。作物中砷的主要形态有无机三价砷As(III)、无机五价砷As(V)和DMA。谷物和蔬菜水果中总砷含量的最大值分别为102和335μg·kg-1。成人和儿童最大日摄入砷量分别为232和205μg。通过分析采样地人体尿砷、作物砷和地方性砷中毒发病率的相关性得出,作物中砷的含量虽未明显超过国家标准,但对人体健康有明显的潜在威胁。政府改水后(饮用水由井水变为达标的自来水),人体的健康风险主要来自作物中的砷,而不是饮用水中的砷。

etection and Health Risk of Arsenic Species in Crops from Arsenic-Affected Areas of Hetao Plain, Inner Mongolia

72 crop samples,81 urine samples and 8 tap water samples were taken from 4 villages of the Hetao Plain of Inner Mongolia to evaluate the relationship between crop arsenic and human health risk. Arsenic species was analyzed by means of high performance liquid chromatography with inductively coupled plasma mass spectrometry ( HPLC-ICP-MS) ,and total arsenic in crops was analyzed using ICP-MS. Results showed that arsenic concentrationwas less than 1 μg·L-1 in tap waters. Arsenic concentrations in urine samples ranged from 4. 50 to 319 μg·L-1 with the mean value of 56. 9 μg·L-1 . DMA was the major As species,accounting for > 70% total As. The main arsenic species were As( III) ,DMA and As (V) in crops. The maximum As concentrations were 102 and 335 μg· kg-1 for grain,vegetable and fruit samples,respectively. Accordingly,the maximum daily arsenic digested by adult and children were 232 and 205 μg,respectively. The relationship between crop arsenic,urine arsenic,and arsenicosis incidence indicated a potential health risk among the local residents,although levels of crop arsenic were not obviously greater than national guideline values. It suggested that after drinking water changed to the low arsenic tap water,human health risk may result from crop arsenic,instead of drinking water arsenic.