湛江红树林沉积物中全/多氟烷基化合物的赋存特征及生态风险

Occurrence and potential ecological risk of per-and polyfluoroalkyl substances in mangrove sediments in Zhanjiang,China

全/多氟烷基化合物(PFASs)已成为全球最受关注的新污染物之一,其由于难降解性、生物累积性和毒性,广泛存在于环境各介质中,危害生态系统健康.“海岸卫士”红树林沉积物是内陆新污染物重要的汇,探究PFASs等新污染物在红树林生态系统中的污染状况和风险水平,对于红树林的保护、管理和污染控制至关重要.本研究选择我国华南最大的湛江红树林为研究区域,旨在探讨红树林沉积物中PFASs的赋存、空间分布特征、可能来源和潜在生态风险.沉积物中PFASs的总浓度为0.29~0.79 ng/g dry wt.,与周边沉积物相比,湛江红树林沉积物中PFASs浓度处于中等水平.全氟羧酸的浓度显著高于全氟磺酸,短链PFASs浓度显著高于长链PFASs,其中全氟丁酸(PFBA)占比最高,其次是全氟辛酸(PFOA)和全氟戊酸(PFPeA).湛江中心城区(金沙湾)、旅游区(特呈岛)和农业区(高桥)红树林沉积物中PFASs浓度略高于养殖区(湖光镇).进一步通过相关性和主成分分析探讨了红树林沉积物中PFASs的可能来源.沉积物中全氟辛酸和全氟辛烷磺酸(PFOS)的风险商均低于1,生态风险较低.本研究为湛江红树林PFASs污染风险评估和管理提供重要数据.

Per-and polyfluoroalkyl substances(PFASs) have become a significant global concern owing to their persistence,bioaccumulation,and toxicity.These substances are widely distributed in various environmental media,threatening ecosystem health.Mangroves,which play a crucial role in coastal protection,are also repositories for inland-originated contaminants.Understanding the contamination levels and risks associated with emerging pollutants like PFASs in mangrove ecosystems is critical for their conservation and management.In this study,we focused on the Zhanjiang mangrove forests,the largest mangrove area in Southern China,to explore the presence,spatial distribution,possible origins,and potential ecological risks of PFASs in sediments.The findings revealed that the total PFAS concentrations in these sediments fluctuated from 0.29 to 0.79 ng/g dry wt.,indicating moderate contamination levels compared with nearby sediments.Notably,perfluorinated carboxylic acid concentrations were significantly higher than those of perfluorinated sulfonic acids,with short-chain PFASs prevailing over long-chain counterparts.Among these,perfluorobutyric acid(PFBA) was the most prevalent,followed by perfluorooctanoic acid(PFOA) and perfluoropentanoic acid(PFPe A).Spatial analysis showed marginally increased concentrations in sediments from urban(Jinsha Bay),tourist(Techeng Island),and agricultural(Gaoqiao) areas compared with those from the aquaculture area(Huguang Town).Correlation and principal component analysis were used to assess potential sources of PFASs in the mangrove sediments.Furthermore,the risk quotients for(PFOA) and perfluorooctane sulfonate(PFOS) within the sediments were less than 1,indicating low ecological risk.The outcomes of this research offer valuable insights into the PFAS contamination status in the Zhanjiang mangroves.