云南不同产区白花蛇舌草中5种金属元素含量分析及健康风险评价

On the content analysis and health risk assessment of the 5 metallic elements in Hedyotis diffusa Willd. from the different areas of Yunnan

利用微波消解-原子荧光光谱法、火焰-石墨炉原子吸收法对云南23个产地白花蛇舌草中Cu、Pb、Cd、Hg和As 5种金属元素质量比进行了测定;并通过靶标危害系数（THQ）和总危害指数（HI）对Cu、Pb、Cd和Hg 4种元素进行非致癌风险评价,用终生致癌风险（R）对As进行致癌风险评价。结果表明,23个产地白花蛇舌草中Cu、Pb、Cd、As和Hg 5种金属元素平均质量比分别为9.65 mg/kg、5.14mg/kg、3.23 mg/kg、0.82 mg/kg和0.04 mg/kg。依据中国药典（2015版）和中国绿色行业标准,这些样品中Cu、As、Hg平均质量比未超标,而Cd、Pb超标,超标率分别为100%和43.47%;少量样品存在Cu、As超标,超标率分别为4.3%和8.96%。瑞丽市勐秀乡样品Cu质量比超标,文山市小街镇样品中Pb、Cd、As质量比远高于标准值,红河州个旧市大屯镇样品As质量比是标准值的4倍多。白花蛇舌草中Cu、Pb、Cd和Hg 4种重金属元素THQ从高到低依次为Cd、Pb、Cu、Hg,且THQ和HI均小于1,表明4种重金属元素中Cd的非致癌风险最高,且THQ/HI达64.58%。此外,23个样品中As的R为4.87×10-5,超出世界卫生组织建议的致癌风险值（1.00×10-5）。研究表明：人体通过白花蛇舌草摄入Cu、Pb、Cd和Hg 4种重金属元素不会对人体造成非致癌伤害;除红河州个旧市和文山市小街镇样品外,云南其他产地白花蛇舌草摄入总As存在低致癌风险。

The present paper is aimed at making an analysis of the content concentration rates of the metal elements through the Microwave Digestion-Atomic Fluorescence Spectrometry（ MD-AFS） and the Flame-Graphite Furnace Atomic Absorption Spectrometry（ GF-AAS）. As a result,we have identified and determined the following 5 metal elements： Cu,Pb,Cd,As and Hg in the plants of Hedyotis diffusa Willd. from the 23 areas of Yunnan. Nevertheless,it remains necessary to do further investigations over the non-carcinogenic health risk hazards likely to be brought about by its content concentration rates of the above said5 metal elements in terms of the target hazard quotient（ THQ）and hazard index（ HI）. Seeing the research need,we have also made the necessary analysis and estimation of the carcinogenic health risks of the plants. In addition,we have also studied the lifetime cancer risk（ R） of the above mentioned plants likely to bring about to the human beings. The results of our investigation can be shown as follows： the average content rates of the 5 metallic elements,including Cu,Pb,Cd,As and Hg in Hedyotis diffusa Willd. plant samples from the 23 areas of Yunnan,have been found equivalent to 9. 65 mg/kg,5. 14 mg/kg,3. 23 mg/kg,0. 82 mg/kg and 0. 04 mg/kg,respectively. In accordance with the Chinese pharmacopoeia 2015 and the state-regulated green industry criteria,the content rates of Cu,As and Hg in the 23 plant samples have all been found below the level of the above said standards,whereas the content rates of Cd and Pb have been confirmed far over by 100% and 43. 47%. More exactly speaking,the content rates of Cu and As have been worked out beyond the uplimit in some few samples by 4. 3% and 8. 69% as well,correspondingly. The literal results can be stated in the following manners：the content rate of Cu in the plants is over the standard proposed at Mengxiu Town,Ruili City,Dehongzhou State. And,those of Pb,Cd and As are beyond the standard illustrated at Xiaojie Town and Wenshang City. At the same time,the content rate of As turns out to be 4 times as high as that illustrated to the plants produced at Datun Town,Gejiu City,and in Honghezhou capital.In addition,the comprehensive evaluation for the THQ of the 4 heavy metals in the aforementioned plants can be stated in the following descending order： Cd 〉Pb 〉Cu〉 Hg,And,in the further analysis,both the THQ and HI rates of the said 4 heavy metals have all been found less than 1,which indicates that Cd represents the greatest risk for human health with its higher THQ/HI rate,that is,64. 58%. Additionally speaking,the R rate of As in the said plants stands about 4. 87 × 10-5,which proves greater than the standard（ 1. 00 × 10-5） of the World Health Organization（ WHO）. Therefore,the above mentioned results help us to arrive at a conclusion that there does not exist more health risks for human beings by intaking Cu,Pb,Cd and Hg from Hedyotis diffusa Willd. plants of Yunnan. In spite of this,there still remains a low carcinogenic risk by absorbing excessive As from the above mentioned plants,except for the samples from Gejiu,Honghe and Xiaojie Wenshan of Yunnan.