贵阳中心区土壤氟的地球化学特征及其环境质量评价

为摸清土壤氟异常对生态环境的影响，利用贵州省多目标区域地球化学调查（1:250 000）项目成果，对贵阳中心区土壤氟的地球化学特征进行了深入研究，并采用全氟指数法对土壤环境质量及其生态环境效应进行初步评价.结果表明:①贵阳中心区土壤氟含量较高，表层、深层土壤氟含量平均值分别为1 143、1 438 mg/kg，且空间分布变化较大；氟含量随土层深度的增加而升高. ②不同类型土壤中氟含量变化较大，其中紫色土中含量（1 306 mg/kg）最高，水稻土次之，石灰土、粗骨土、黄壤等差别较小，其含量范围在1 099~1 167 mg/kg之间. ③土壤氟含量与其母岩呈显著正相关性，且土壤中氟含量较母岩更高，表明风化成土过程中存在一定富集，土壤氟与成土母岩之间具有一定继承性. ④土壤氟环境质量评价结果表明，研究区土壤存在局部氟污染（异常），污染区、警戒区、安全区和清洁区所占比例分别为13.6%、62.2%、19.2%和5.0%. ⑤生态环境效应初步调查结果显示，局部土壤受氟污染区的油菜和稻谷样品中氟含量范围分别为1.86~2.68和10.40~13.50 mg/kg，同时地下水也受到一定程度的氟污染.因此，贵阳中心区土壤氟含量较高，局部土壤已受到氟污染，可能会对农产品质量、饮水安全及人体健康产生一定影响，建议政府部门及科研工作者予以高度重视. 

Geochemical Characteristics of Fluorine in Soils and Its Environmental Quality in Central District of Guiyang

Guizhou is one of provinces where the endemic fluorine diseases are most serious in China. Soil is an important environmental factor for fluorine pollution. In order to find out the influence of soil fluoride anomaly on ecological environment, the soil fluorine content and its geochemical distribution characteristics were studied in depth, and the environmental quality of the soil fluorine in the central area of Guiyang City and ecological environmental effects in the abnormal fluorine area were evaluated preliminarily by using full fluorine index method based on the analysis results of the multipurpose regional geochemical investigation specification (1:250, 000) relating to soil, rock and crop in the central area of Guiyang City. The results show that: (1) Soil in the central area of Guiyang City has high fluorine content. The mean values of fluorine contents of the shallow and deep layers of soil are 1, 143 mg/kg and 1, 438 mg/kg, and have bigger spatial distribution change. (2) The fluorine content from different types of soil varies greatly. The purple soil has the highest fluorine content (1, 306 mg/kg), followed by the paddy soil. The fluorine contents of the limestone soil, skeleton soil and yellow soil have a small difference, which falls into the range of 1, 099-1, 167 mg/kg. (3) The fluorine contents of soil and their source rocks have positive correlation, which means that there has certain enrichment during soil forming via rock weathering. In addition, compared with the source rock, the fluorine content in soil is higher. (4) The result of the environmental quality evaluation with the full fluorine index method shows that the soil in the research area has local fluorine pollution with accounting for 13.6%, 62.2, 19.2% and 5.0% of polluted, guard, safe and clean area, respectively. (5) Furthermore, the survey results of local area soils polluted by fluorine also show that fluorine content of rape and rice samples ranges from 1.86 to 2.68 mg/kg and 10.40 to 13.50 mg/kg, respectively. Meanwhile, the groundwater has been a certain degree of fluorine pollution. Therefore, the soil in the central area of Guiyang City has high fluorine content and the fluorine in the local soil is abnormal, which threatens the environmental quality of the regional soil and human health probably, it is recommended that the relevant governmental departments and science researchers should pay attention to soil pollution of fluorine heavily.