Shandong Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, PR China; International Joint Laboratory of Agricultural Food Science and Technology of Universities of Shandong, Dezhou University, Dezhou 253023, PR China.
Shandong Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, PR China; International Joint Laboratory of Agricultural Food Science and Technology of Universities of Shandong, Dezhou University, Dezhou 253023, PR China.
Ecotoxicol Environ Saf. 2024 Aug;281:116643. doi: 10.1016/j.ecoenv.2024.116643. Epub 2024 Jun 25.
Selenium (Se) pollution is mainly caused by anthropogenic activities, and the resulting biosecurity concerns have garnered significant attention in recent years. Using one-compartmental toxicokinetic (TK) modelling, this study explored the kinetic absorption, sub-tissue distribution, and elimination processes of the main Se species (selenate, Se(VI)) in the cultivated aerobic soil of the earthworm Eisenia fetida. The bio-accessibility of earthworm-derived Se was assessed using an in vitro simulated gastrointestinal digestion test to evaluate its potential trophic risk. The results demonstrated that Se accumulated in the pre-clitellum (PC) and total tissues (TT) of earthworms in a time- and dose-dependent manner. The highest Se levels in the PC, post-clitellum (PoC), and TT were 70.54, 57.93, and 64.26 mg/kg during the uptake phase, respectively. The kinetic Se contents in the earthworms PC and TT were consistent with the TK model but not with PoC. The earthworm TT exhibited a faster uptake (K = 0.83-1.02 mg/kg/day) and elimination rate of Se (K = 0.044-0.049 mg/kg/day), as well as a shorter half-life time (LT = 15.88-14.22 days) than PC at low soil Se levels (≤5 mg/kg). Conversely, the opposite trend was observed with higher Se concentrations (10 and 20 mg/kg). These results are likely attributable to the tissue specificity and concentration of the toxicant. Earthworms PC and TT exhibited a higher kinetic Se accumulation factor (BAF) than steady-state BAF (BAF), with values ranging from 8 to 24 and 3-13, respectively. Furthermore, the bio-accessibility of earthworm-derived Se to poultry ranged from 66.25 % to 84.35 %. As earthworms are at the bottom of the terrestrial food chain, the high bio-accessibility of earthworm-derived Se poses a potential risk to predators. This study offers data support and a theoretical foundation for understanding the biological footprint of soil Se and its toxicological impacts and ecological hazards.
硒（Se）污染主要是由人为活动引起的，近年来，其生物安全性问题引起了人们的广泛关注。本研究采用一室毒代动力学（TK）模型，研究了主要硒形态（硒酸盐，Se（VI））在赤子爱胜蚓（Eisenia fetida）有氧土壤中的动力学吸收、亚组织分布和消除过程。采用体外模拟胃肠道消化试验评估蚯蚓源硒的生物可利用性，评估其潜在的营养风险。结果表明，硒在蚯蚓的前生殖带（PC）和总组织（TT）中随时间和剂量呈时间和剂量依赖性积累。在吸收阶段，PC、后生殖带（PoC）和 TT 中的硒含量最高分别为 70.54、57.93 和 64.26mg/kg。蚯蚓 PC 和 TT 的动力学硒含量与 TK 模型一致，但与 PoC 不一致。在低土壤硒水平（≤5mg/kg）下，蚯蚓 TT 的硒摄取速度（K=0.83-1.02mg/kg/d）和消除速度（K=0.044-0.049mg/kg/d）较快，半衰期（LT=15.88-14.22d）较短，而在较高的硒浓度（10 和 20mg/kg）下则相反。这一结果可能归因于组织特异性和毒物浓度。蚯蚓 PC 和 TT 的动力学硒积累因子（BAF）高于稳态 BAF（BAF），分别为 8-24 和 3-13。此外，蚯蚓源硒对家禽的生物可利用性为 66.25%-84.35%。由于蚯蚓处于陆地食物链的底层，蚯蚓源硒的高生物可利用性对捕食者构成了潜在风险。本研究为了解土壤硒的生物学足迹及其毒理学影响和生态危害提供了数据支持和理论基础。
