中文摘要：

鉴于流域尺度内水稻植株不同组织中总汞和甲基汞含量及人群进食稻米的汞暴露风险研究较少,系统采集了贵州省铜仁市受万山废弃汞矿影响的瓦屋河流域内水稻植株及对应根际土壤样品,分析水稻植株不同组织中的w（总汞）、w（甲基汞）及其影响因素,以及流域内人群食用稻米的汞暴露风险.结果表明：瓦屋河流域水稻精米中w（总汞）平均值为（14.2±7.0）μg/kg（范围为4.1-34.0μg/kg,n=24）,精米中w（甲基汞）平均值为（7.229±3.957）μg/kg（范围为1.974-17.364μg/kg,n=24）.精米中w（总汞）与水稻茎、叶中w（总汞）均呈较显著正相关（R=0.531,P〈0.01;R=0.499,P〈0.05）,精米中w（甲基汞）与水稻根、茎中w（甲基汞）也均呈显著正相关（R=0.525,P〈0.01;R=0.612,P〈0.01）;w（总汞）、w（甲基汞）均与土壤理化参数存在一定正相关关系,并均与距污染源距离呈负相关.根据精米中w（甲基汞）平均值,并按照US EPA（美国国家环境保护局）推荐的甲基汞日暴露量（ID）和危害指数（HI）的评估方法计算的瓦屋河流域居民甲基汞日暴露量为（0.075±0.041）μg/（kg·d）,低于较为严厉的US EPA推荐的甲基汞日安全摄入量（Rf D）,危害指数为0.75.从平均状况来看,人体摄入该地区生产的精米相对较为安全.

英文摘要：

In view of the lack of knowledge of total mercury（ THg） and methylmercury（ Me Hg） in different tissues of rice plants and the risk of mercury exposure to rice at the river basin scale,rice plants and the rhizosphere soil in Wawu River Watershed flowing through the Tongren Wanshan abandoned mercury（ Hg） mining area in Guizhou Province were collected. The goal was to clearly understand concentrations of THg and Me Hg in different tissues of rice plants and Hg exposure risks via rice consumption. The results showed that mean concentration of THg in rice grain was（ 14. 2 ± 7. 0） μg/kg with range of 4. 1 to 34. 0 μg/kg（ n = 24）,and Me Hg in rice grain ranged from 1. 974 μg/kg to 17. 364 μg/kg with the mean value of（ 7. 229 ± 3. 957） μg/kg（ n = 24）. Grain THg was significantly positively correlated with stalk and leaf THg（ R = 0. 531,P〈0. 01; R = 0. 499,P〈0. 05）,and Me Hg was positively correlated with root and stalk Me Hg（ R = 0. 525,P〈0. 01; R = 0. 612,P〈0. 01）. A positive correlation between THg and Me Hg concentrations with soil parameters,and a significant negative correlation with distance from Hg contaminated sites,were observed. According to the mean value of Me Hg in rice grain and the calculation method of the ID and HI recommended by US EPA,Me Mg ID and HI values were（ 0. 075 ± 0. 041） μg/（ kg·d） and 0. 75,which were lower than the severe Rf D level recommended by US EPA. On average,it is still relatively safe for humans to eat rice produced by the region.