Department of Environmental Science and Policy, University of Milan, Via Celoria 26, 20133, Milan, Italy.
Unitech NOLIMITS, Imaging facility, University of Milan, Via Golgi 19, 20133, Milan, Italy.
Water Res. 2019 Dec 1;166:115082. doi: 10.1016/j.watres.2019.115082. Epub 2019 Sep 13.
Plastic particle ingestion has become of concern as a possible threat to human health. Previous works have already explored the presence of microplastic (MP) in bottled drinking water as a source of MP intake. Here, we consider the release of MP particles from single-use PET mineral water bottles upon exposure to mechanical stress utilizing SEM plus EDS, which allows the implementation of morphological and elemental analysis of the plastic material surface and quantification of particle concentrations in sample water. The aim of this study was to better evaluate the sources of MP intake from plastic bottles, especially considering the effect of daily use on these bottles such as the abrasion of the plastic material. For that, we analysed MP release of PET bottlenecks and HDPE caps on their surfaces after a series of bottle openings/closings (1 x, 10 x, 100 x). Furthermore, we investigated, if the inner surface of the PET bottles released MPs, counted particle increase of the water and identified MPs in the PET bottled water after exposing the bottles to mechanical stress (squeezing treatment; none, 1 min, 10 min). The results showed a considerable increase of MP particle occurrence on the surface of PET and HDPE material (bottlenecks and caps) after opening and closing the bottles. After 100 times the effect was impressive, especially on caps. Moreover, great differences exist in cap abrasion between brands which uncovers a discrepancy in plastic behavior of brands. Interestingly, particle concentrations in the bottled mineral water did not significantly increase after exposure to mechanical stress (squeezing treatment). The morphological analysis of the inner wall surface of the bottles supported this observation, as no stress cracks could be detected after the treatment, implying that the bottles itself are not a consistent source of MP particles after this extent of mechanical stress. However, chances of MP ingestion by humans increase with frequent use of the same single-use plastic bottle, though only from the bottleneck-cap system.
塑料颗粒摄入已成为对人类健康的潜在威胁，引起了广泛关注。先前的研究已经探讨了瓶装饮用水中微塑料（MP）的存在，认为其是人类摄入微塑料的一个来源。在此，我们利用扫描电子显微镜（SEM）和能量色散 X 射线光谱仪（EDS）研究了一次性 PET 矿泉水瓶在受到机械压力时释放微塑料颗粒的情况。SEM-EDS 可以对塑料材料表面进行形态和元素分析，并对样品水中的颗粒浓度进行定量分析。本研究的目的是更好地评估从塑料瓶摄入微塑料的来源，特别是考虑到日常使用对这些瓶子的影响，例如塑料材料的磨损。为此，我们分析了一系列开瓶/关瓶操作后 PET 瓶瓶颈和 HDPE 瓶盖表面的 MP 释放情况（1 次、10 次、100 次）。此外，我们还研究了 PET 瓶的内表面在受到机械压力（挤压处理；无、1 分钟、10 分钟）时是否会释放微塑料，并对暴露后的 PET 瓶装矿泉水进行了微塑料计数和鉴定。结果表明，开瓶和关瓶后，PET 和 HDPE 材料（瓶颈和瓶盖）表面的微塑料颗粒出现了明显增加。开瓶 100 次后，效果非常显著，尤其是在瓶盖上。此外，不同品牌的瓶盖磨损程度存在较大差异，这揭示了品牌之间塑料行为的差异。有趣的是，暴露于机械压力（挤压处理）后，瓶装矿泉水中的颗粒浓度并没有显著增加。对瓶壁内表面的形态分析支持了这一观察结果，因为处理后没有发现应力裂纹，这意味着在受到如此大的机械压力后，瓶子本身不会成为微塑料颗粒的持续来源。然而，由于频繁使用同一个一次性塑料瓶，人类摄入微塑料的风险会增加，尽管只是来自瓶颈和瓶盖系统。
