Beggio Giovanni, Roman Marco, Mitrano Denise M, Bravin Matthieu N, Ndiforngu Ateh Suh Nkwekeu, Sandon Annalisa, Bonato Tiziano, Lavagnolo Maria Cristina
Department of Civil, Environmental and Architectural Engineering, University of Padova Via Marzolo 9 35131 Padova Italy
Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice Via Torino 155 30172 Venice Italy.
Environ Sci Nano. 2025 Jul 15;12(8):3896-3903. doi: 10.1039/d5en00328h. eCollection 2025 Aug 8.
Standardized methods are essential for generating reliable and reproducible data to support risk assessment and decision-making related to soil contamination by environmental pollutants, including nanoplastics (NPs). This study evaluated the ability of the RHIZOtest method, a standardized soil-plant exposure system, in providing a high-throughput testing platform for investigating NP phytoavailability. As a proof of concept, tomato plants were exposed to artificial soil spiked with model NPs at concentrations of 400 and 4000 mg kg dm. Palladium (Pd)-doped polystyrene particles (PS-P) (a Z-average diameter of 210 nm, a surface charge zeta potential of -45.20 ± 032 mV, a polydispersity index of 0.1, and a Pd doping ratio of 0.295% w/w Pd to PS-P) were used as surrogates for NPs. Pd content was measured as a proxy for quantifying PS-P uptake. After eight days of exposure, Pd was detected in both the roots and shoots of plants grown on both spiked soils, confirming PS-P uptake and translocation. On average, 5 ± 1% of the spiked PS-P were taken up by the plants across spiking levels. Root concentration factors varied slightly between the lower and higher levels (31 ± 2% and 24 ± 3%, respectively), while translocation factors remained similar (∼25%). Root biomass was significantly reduced compared to controls, suggesting possible concentration-dependent PS-P rhizotoxicity. Notably, the limited variability in concentration values measured in roots (±11%) and shoots (±23%), along with near-complete mass balance recovery (97-100%), demonstrated the reliability of the RHIZOtest in accurately and consistently quantifying NP uptake while accounting for rhizosphere processes.
标准化方法对于生成可靠且可重复的数据以支持与环境污染物（包括纳米塑料（NPs））导致的土壤污染相关的风险评估和决策至关重要。本研究评估了RHIZOtest方法（一种标准化的土壤-植物暴露系统）为研究NP植物有效性提供高通量测试平台的能力。作为概念验证，将番茄植株暴露于添加了浓度为400和4000 mg kg dm的模型NP的人工土壤中。使用钯（Pd）掺杂的聚苯乙烯颗粒（PS-P）（Z平均直径为210 nm，表面电荷zeta电位为-45.20±032 mV，多分散指数为0.1，Pd与PS-P的掺杂比为0.295% w/w Pd）作为NP的替代物。测量Pd含量作为量化PS-P吸收的替代指标。暴露八天后，在两种添加土壤上生长的植物的根和茎中均检测到Pd，证实了PS-P的吸收和转运。平均而言，在不同添加水平下，植物吸收了5±1%的添加PS-P。较低和较高添加水平下的根浓度因子略有不同（分别为31±2%和24±3%），而转运因子保持相似（约25%）。与对照相比，根生物量显著降低，表明PS-P可能具有浓度依赖性的根毒性。值得注意的是，根（±11%）和茎（±23%）中测量的浓度值变化有限，以及近乎完全的质量平衡恢复（97-100%），证明了RHIZOtest在准确且一致地量化NP吸收同时考虑根际过程方面的可靠性。
