State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, China.
Quantum Design (Beijing) Co., Ltd, Beijing, China.
Nat Nanotechnol. 2022 Jan;17(1):76-85. doi: 10.1038/s41565-021-00998-x. Epub 2021 Nov 11.
Silicone-rubber baby teats used to bottle-feed infants are frequently disinfected by moist heating. However, infant exposure to small microplastics (<10 μm) potentially released from the heated teats by hydrothermal decomposition has not been studied, owing to the limitations of conventional spectroscopy in visualizing microplastic formation and in characterizing the particles at the submicrometre scale. Here both the surfaces of silicone teats subjected to steam disinfection and the wash waters of the steamed teats were analysed using optical-photothermal infrared microspectroscopy. This new technique revealed submicrometre-resolved steam etching on and chemical modification of the teat surface. Numerous flake- or oil-film-shaped micro(nano)plastics (MNPs) (in the size range of 0.6-332 μm) presented in the wash waters, including cyclic and branched polysiloxanes or polyimides, which were generated by the steam-induced degradation of the base polydimethylsiloxane elastomer and the polyamide resin additive. The results indicated that by the age of one year, a baby could ingest >0.66 million elastomer-derived micro-sized plastics (MPs) (roughly 81% in 1.5-10 μm). Global MP emission from teat disinfection may be as high as 5.2 × 10 particles per year. Our findings highlight an entry route for surface-active silicone-rubber-derived MNPs into both the human body and the environment. The health and environmental risks of the particles are as yet unknown.
用于奶瓶喂养婴儿的硅橡胶奶嘴经常通过湿热加热进行消毒。然而，由于传统光谱学在可视化微塑料形成和亚微米尺度颗粒特征方面的局限性，婴儿暴露于由热分解从加热奶嘴中释放的小尺寸微塑料（<10μm）的情况尚未得到研究。在这里，使用光热红外微光谱法分析了经受蒸汽消毒的硅橡胶奶嘴的表面以及蒸汽消毒后的奶嘴的洗涤水。这项新技术揭示了蒸汽在奶嘴表面的亚微米级刻蚀和化学改性。在洗涤水中存在大量片状或油膜状的微（纳）塑料（MNPs）（尺寸范围为 0.6-332μm），包括环状和支化聚硅氧烷或聚酰亚胺，它们是由基聚二甲基硅氧烷弹性体和聚酰胺树脂添加剂的蒸汽诱导降解产生的。研究结果表明，在一岁时，婴儿可能摄入>0.66 万个弹性体衍生的微尺寸塑料（MPs）（1.5-10μm 范围内约为 81%）。全球因奶嘴消毒而产生的微塑料排放量可能高达 5.2×10 个/年。我们的研究结果强调了表面活性剂硅橡胶衍生的 MNPs 进入人体和环境的途径。这些颗粒的健康和环境风险尚不清楚。
