College of Architecture and Environment & Healthy Food Evaluation Research Center, Sichuan University, Chengdu, 610065, PR China.
College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu, 610059, PR China.
Environ Pollut. 2019 Jun;249:423-433. doi: 10.1016/j.envpol.2019.03.044. Epub 2019 Mar 14.
The high concentration of fluoride (F) in soils has become a rising concern for its toxicity to microbes, plants, animals and human health. In the present study, the spatial and vertical distribution, health risk assessment and anthropogenic sources of F in farmland soils in an industrial area dominated by phosphate chemical plants were studied. Concentrations of total fluoride (TF) and water soluble fluoride (WSF) in the surface soils decreased with distance within the range of 2500 m at the prevailing downwind of the industrial area. The soil TF and WSF concentrations in 0-40 cm profiles were higher than those in 40-100 cm layers in the industrial area. At the prevailing downwind of the industrial area within 700 m, the hazard quotient values of human exposure to surface soils were higher than 1, indicating that a potential risk may exist for human health in this area. The main exposure pathway for children and adults was oral ingestion and particulate inhalation, respectively. The source apportionment model of soil F was modified based on years' historical data and experimental data. The results showed that the proportion of anthropogenic sources of soil F was dustfalls (69%) > irrigation water (23%) > air (5%) > chemical fertilizers (3%) in the industrial area. The high F concentration of dustfalls was mainly due to the phosphate rock, phosphogypsum, and surface soils with high F contents from the factories. In order to safeguard human health and alleviate hazards of F to surroundings, the control of pollutants emission from factories was a basic and vital step to reduce F in the soils in industrial areas.
土壤中高浓度的氟（F）因其对微生物、植物、动物和人类健康的毒性而引起人们的关注。本研究以磷化工为主导的工业区域农田土壤为研究对象，探讨了其 F 的空间和垂直分布、健康风险评估和人为来源。在盛行风下风方向 2500m 范围内，表层土壤中总氟（TF）和水溶性氟（WSF）的浓度随距离的增加而降低。工业区域 0-40cm 剖面的土壤 TF 和 WSF 浓度高于 40-100cm 层。在工业区域盛行风下风方向 700m 范围内，人类对表层土壤的暴露危害商值高于 1，表明该区域可能存在对人类健康的潜在风险。儿童和成人的主要暴露途径分别为经口摄入和颗粒物吸入。基于多年的历史数据和实验数据对土壤 F 的源分配模型进行了修正。结果表明，工业区域土壤 F 的人为来源比例为扬尘（69%）＞灌溉水（23%）＞大气（5%）＞化肥（3%）。扬尘中高浓度 F 主要来源于工厂中的磷矿石、磷石膏和高 F 含量的表土。为了保障人类健康，减轻 F 对周围环境的危害，控制工厂污染物的排放是减少工业区域土壤中 F 的基本和关键步骤。
