College of Architecture and Environment, Sichuan University, Chengdu 610065, China; Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Yibin 644000, China.
College of Architecture and Environment, Sichuan University, Chengdu 610065, China.
Sci Total Environ. 2021 Jun 1;771:144809. doi: 10.1016/j.scitotenv.2020.144809. Epub 2021 Jan 27.
Perfluorinated compounds (PFCs) are organo-fluorine compounds which have been identified at significant levels in soils due to their widespread usage in industrial and commercial applications. However, few studies are available regarding the occurrence of PFCs in the environment of endemic fluorosis areas. To address the issue, soils collected from an endemic fluorosis area of southwestern China were analyzed for the distribution of fluorine and 21 kinds of PFCs. The average water-soluble fluorine concentration in cultivated soil (4.87 mg kg) was significantly higher than that in uncultivated soil (3.15 mg kg), which mainly ascribed to the utilization of fluorine-enriched fertilizers during agricultural practices. Concentrations of ΣPFCs in all soils ranged from 0.508 to 6.83 ng g, with an average of 2.81 ng g, dominated by perfluorononanoic acid (PFNA) and perfluorooctanoic acid (PFOA). Highest ΣPFCs was found in the soil samples collected from cropland with intensive agricultural activities. Long-chain PFCs, including four perfluoroalkylcarboxylic acids (PFCAs, C ≥ 8) and one perfluoroalkylsulfonic acids (PFSAs) (perfluorooctane sulfonate (PFOS), C8), exhibited high levels in soils, probably due to their higher hydrophobicity and lower water-solubility than short-chain PFCs. While in sediments, short-chain PFCAs were the dominant compounds. Based on correlation analysis, the relationship between total fluorine and PFCs was insignificant, and soil organic matter was a relevant factor affecting PFCs distribution in soils. This study is expected to present a more comprehensive information about fluorine contamination under the influence of agricultural activities in an endemic fluorosis area.
全氟化合物(PFCs)是一类有机氟化合物,由于其在工业和商业应用中的广泛使用,在土壤中已被检测到相当高的浓度。然而,关于 PFCs 在地方性氟中毒地区环境中存在的研究较少。为了解决这一问题,分析了中国西南地方性氟中毒地区土壤中氟和 21 种 PFCs 的分布。耕地土壤中水溶性氟的平均浓度(4.87mg/kg)明显高于未耕地土壤(3.15mg/kg),这主要归因于农业生产中使用了富氟肥料。所有土壤中ΣPFCs 的浓度范围为 0.508 至 6.83ng/g,平均值为 2.81ng/g,主要由全氟壬酸(PFNA)和全氟辛酸(PFOA)组成。在农业活动密集的耕地土壤中,ΣPFCs 的含量最高。长链 PFCs,包括四种全氟烷基羧酸(PFCAs,C≥8)和一种全氟烷基磺酸(PFSAs)(全氟辛烷磺酸(PFOS),C8),在土壤中含量较高,可能是由于其疏水性高于短链 PFCs,水溶性低于短链 PFCs。而在沉积物中,短链 PFCAs 是主要的化合物。基于相关性分析,总氟与 PFCs 之间的关系不显著,土壤有机质是影响土壤中 PFCs 分布的相关因素。本研究有望为了解农业活动影响下地方性氟中毒地区的氟污染提供更全面的信息。