Abstract:

The contamination problem of per- and poly-fluorinated compounds (PFASs) in edible plants was of growing concern. Nineteen maize samples were collected from agricultural soil near a fluorine chemical park in Fuxin city, Liaoning province, to evaluate the contamination of PFASs around typical fluorine industry parks. The concentration of seventeen individual-PFASs was identified in the root, shoot, leaf and kernel of maize. The spatial distribution and accumulation patterns of PFASs were analyzed using correlation relationships and ArcGis software. The results showed that (1) the total concentration of PFASs (ΣPFASs) ranged from 15.88 to 62.75 ng·g^-1. The main compounds were the short-chain PFASs (C≤6), PFOA (perfluorooctanoic acid), and PFOS (perfluorooctane sulfonate). (2) PFASs were mainly accumulated in the leaf. ∑PFASs in the leaf were higher than those in the root, shoot and kernel. In addition, the difference between carbon length and the functional group also influenced the concentration and composition of PFASs in maize. (3) PFOA and PFOS tend to accumulate in the root, whereas short-chain PFASs are easily migrated in the interior of maize. The Spearman correlation analysis implied that ∑PFASs in root had a significant positive relationship with those in the shoot (r=0.772, P=0.001) or leaf (r=0.400, P=0.046). ∑PFASs in maize decreased with the increasing distance from the fluorine chemical park. Compared with the PFAS concentration in maize within 1-2 km of the fluorine chemical park, the PFASs concentration in maize decreased by 71.56% when the distance between maize and the fluorine chemical park was more than 4 km, indicating that the fluorine chemical production may be a potential point contamination source. Soils near fluorine chemical park were contaminated by industrial wastewater and sludge, and PFASs from contaminated soils were easy to be absorbed by roots, leading to accumulation in maize; atmospheric and dust uptake was considered to be another source of high PFAS concentrations in maize leaf. Our study analyzed the concentrations and profiles of PFASs in maize around the fluorine industry park, and can be used for pollution control and government of PFASs in plants around typical point pollution sources.

Key words: per- and poly-fluorinated substances, new pollutants, maize, accumulation, fluorine industry, contamination

摘要：

食源性植物中全氟/多氟化合物（Per- and poly-fluorinated substances，PFASs）的污染问题已经引起人们的广泛关注。为研究典型氟化工园区周边玉米中PFASs的污染特征，在辽宁阜新氟化工园区周边的农用土壤中采集19个玉米样品，分析了根、茎、叶及果实中17种PFASs单体的含量与组成，并结合相关性分析及ArcGis软件阐明了玉米中PFASs的富集规律及空间分布特征。结果表明，（1）氟化工园区周边农用地中玉米植株内总PFASs含量（∑PFASs）水平为15.88-620.7 ng·g^-1，主要检出物质为短链（C≤6）PFASs、PFOA（perfluorooctanoic acid，全氟辛酸）和PFOS（perfluorooctane sulfonate，全氟辛烷磺酸）。（2）叶片是最具富集能力的器官。PFASs在叶片中总含量远高于其在根、茎及果实中含量。此外，碳链长度及官能团结构会影响玉米体内PFASs的含量。（3）PFOA与PFOS倾向富集在根部，而短链PFASs易在玉米植株内迁移。Spearman 相关性分析表明，PFASs在根系中的总含量与其在茎（r=0.772，P=0.001）及叶片（r=0.400，P=0.046）中具有显著的正相关性。随着与氟化工园区距离的增加，玉米作物∑PFASs呈明显下降趋势。与氟化工园区周边1-2 km范围内玉米中PFASs含量相比，当玉米与氟化工园区的距离超过4 km时，其体内PFASs含量约减少了71.6%，表明当地氟化工生产可能是重要的点污染源。临近氟化工园区的土壤更容易受到工业废水和废渣的污染，玉米根系易从受污染的土壤中摄入PFASs，从而在体内发生富集作用；大气和灰尘摄入被认为是玉米叶片中高含量PFASs的另一来源。该研究分析了氟化工园区周边玉米中PFASs的含量与组成，为特征点污染源周边植物中PFASs的污染防治与治理提供了帮助。

关键词: 全氟/多氟化合物, 新污染物, 玉米, 富集, 氟化工, 污染