Abstract：
Most studies on nanoplastics (NPs) focus on aquatic environments, overlooking their combined bioaccumulation with pollutants in terrestrial ecosystems. This study addresses a part of this gap by investigating how polystyrene nanoplastics (PS-NPs) affect the bioaccumulation and translocation of lead (Pb) in Hordeum vulgare L. plants. Using the RHIZOtest device for precise soil contamination control, we quantified PS-NPs (50 nm) in plant shoots via pyrolysis-gas chromatography/mass spectrometry (Py-GCMS) after plant KOH digestion. Our findings revealed that PS-NPs reduce Pb bioaccumulation and make adsorbed Pb onto PS-NPs less bioavailable to plants. For the highest Pb concentration, the Pb uptake index (PUI) followed the trend: Free Pb > NPs + Pb > Pb primary adsorbed by NPs, showing reduced Pb translocation to shoots in the presence of PS-NPs. Moreover, the presence of Pb decreased the bioavailability of PS-NPs probably in response to PS-NPs aggregation or modified charge. The PS-NPs concentrations in shoots range from 275.2 to 400 μg g-1, representing 3.9 to 5.75% of the total PS-NPs. This study highlights the intricate interactions between nanoplastics and metals in soil-plant systems and emphasizes the need for further research on their combined effects and potential risks to food safety.
摘要：
大多数关于纳米塑料（NPs）的研究都集中在水生环境中，俯瞰它们与陆地生态系统中污染物的联合生物累积。本研究通过研究聚苯乙烯纳米塑料（PS-NP）如何影响大麦植物中铅（Pb）的生物积累和转运来解决这一差距的一部分。使用RHIZOtest设备进行精确的土壤污染控制，在植物KOH消化后，我们通过热解-气相色谱/质谱（Py-GCMS）定量了植物芽中的PS-NP（50nm）。我们的发现表明，PS-NP降低了Pb的生物积累，并使吸附在PS-NP上的Pb对植物的生物可利用性降低。对于最高的Pb浓度，Pb吸收指数(PUI)遵循以下趋势:游离Pb>NPs+Pb>NPs初级吸附Pb,在存在PS-NP的情况下，Pb易位减少。此外，铅的存在降低了PS-NP的生物利用度，可能是由于PS-NP的聚集或修饰的电荷。芽中的PS-NP浓度范围为275.2至400μgg-1，占总PS-NP的3.9至5.75％。这项研究强调了土壤-植物系统中纳米塑料和金属之间复杂的相互作用，并强调需要进一步研究它们的综合影响和对食品安全的潜在风险。
