Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China.
The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; State Key Laboratory of Marine Pollution, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR, China.
J Hazard Mater. 2021 Mar 15;406:124726. doi: 10.1016/j.jhazmat.2020.124726. Epub 2020 Dec 3.
Microplastics (MPs) contain high levels of polybrominated diphenyl ethers (PBDEs), which can leach to organism tissues upon ingestion, thereby leading to increased chemical exposure. However, leaching kinetics of inherent contaminants from ingested MPs are poorly studied. The present study characterized the leaching kinetics of PBDEs from sub-millimeter sized MPs in fish oil at relevant body temperatures for marine organisms and assessed exposure risk of MPs for cod fish by a biodynamic model. Diffusion coefficients (D) of PBDEs are in the ranges of 1.98 × 10-2.35 × 10 m·s in polystyrene, 1.89 × 10-2.07 × 10 m·s in acrylonitrile butadiene styrene, and 4.26 × 10-1.72 × 10 m·s in polypropylene. A linear function obtained between log D of BDE-209 and glass-transition temperature of MPs allows estimation of D of BDE-209 contained in other common types of MPs present in the gastrointestinal lipid. The biota-plastic accumulation factors of PBDEs for three plastics were in the range of 4.77 × 10-4.03 × 10. Although bioaccumulation of MPs-affiliated PBDEs is accelerated by oil in the gastrointestinal tract, the modeled steady-state concentrations of PBDEs in cod tissue lipid through ingestion of MPs under the most likely conditions were below the lower end of the global PBDE concentration, implicating that ingestion of MPs by organisms remains a negligible pathway in general.
微塑料 (MPs) 含有高水平的多溴二苯醚 (PBDEs)，这些物质在被摄入后会浸出到生物体组织中，从而导致化学物质暴露量增加。然而，摄入的 MPs 中固有污染物的浸出动力学研究还很少。本研究在相关的海洋生物体温下，在鱼油中对亚毫米级 MPs 中 PBDEs 的浸出动力学进行了表征，并通过生物动力学模型评估了 MPs 对鳕鱼的暴露风险。聚苯乙烯中 PBDEs 的扩散系数 (D) 在 1.98×10-2.35×10 m·s 之间，丙烯腈-丁二烯-苯乙烯共聚物中为 1.89×10-2.07×10 m·s，聚丙烯中为 4.26×10-1.72×10 m·s。BDE-209 的 log D 与 MPs 玻璃化转变温度之间得到的线性函数允许估计胃肠道脂质中存在的其他常见类型 MPs 中 BDE-209 的 D。三种塑料中 PBDEs 的生物-塑料积累因子在 4.77×10-4.03×10 之间。尽管在胃肠道中的油会加速 MPs 相关 PBDEs 的生物积累，但在最有可能的条件下通过摄入 MPs 摄入到鳕鱼组织脂质中的 PBDEs 的稳态浓度仍低于全球 PBDE 浓度的低端，这表明生物体摄入 MPs 通常仍然是一种微不足道的途径。
