Abstract：
Humans ingest particles and fibers on daily basis. Non-digestible carbohydrates are beneficial to health and food additives are considered safe. However, titanium dioxide (E171) has been banned in the European Union because the European Food Safety Authority no longer considers it non-genotoxic. Ingestion of microplastics and nanoplastics are novel exposures; their potential hazardous effects to humans have been under the radar for many years. In this review, we have assessed the association between oral exposure to man-made particles/fibers and genotoxicity in gastrointestinal tract cells and secondary tissues. We identified a total of 137 studies on oral exposure to particles and fibers. This was reduced to 49 papers with sufficient quality and relevance, including exposures to asbestos, diesel exhaust particles, titanium dioxide, silver nanoparticles, zinc oxide, synthetic amorphous silica and certain other nanomaterials. Nineteen studies show positive results, 25 studies show null results, and 5 papers show equivocal results on genotoxicity. Recent studies seem to show null effects, whereas there is a higher proportion of positive genotoxicity results in early studies. Genotoxic effects seem to cluster in studies on diesel exhaust particles and titanium dioxide, whereas studies on silver nanoparticles, zinc oxide and synthetic amorphous silica seem to show mainly null effects. The most widely used genotoxic tests are the alkaline comet assay and micronucleus assay. There are relatively few results on genotoxicity using reliable measurements of oxidatively damaged DNA, DNA double strand breaks (γH2AX assay) and mutations. In general, evidence suggest that oral exposure to particles and fibers is associated with genotoxicity in animals.
摘要：
人类每天摄取颗粒和纤维。不可消化的碳水化合物对健康有益，食品添加剂被认为是安全的。然而,二氧化钛（E171）已在欧盟被禁止，因为欧洲食品安全局不再认为它具有非遗传毒性。微塑料和纳米塑料的摄入是新的暴露;它们对人类的潜在危险影响已经受到多年的关注。在这次审查中,我们评估了口服暴露于人造颗粒/纤维与胃肠道细胞和次级组织遗传毒性之间的相关性.我们确定了总共137项关于口腔暴露于颗粒和纤维的研究。这减少到49篇具有足够质量和相关性的论文，包括接触石棉，柴油机废气颗粒，二氧化钛,银纳米粒子，氧化锌，合成无定形二氧化硅和某些其他纳米材料。19项研究显示出积极的结果，25项研究显示结果无效，5篇论文在遗传毒性方面显示出模棱两可的结果。最近的研究似乎显示出无效效果，而早期研究中遗传毒性阳性结果的比例更高。基因毒性效应似乎集中在对柴油机废气颗粒和二氧化钛的研究中，而对银纳米粒子的研究，氧化锌和合成无定形二氧化硅似乎主要显示无效效果。最广泛使用的基因毒性试验是碱性彗星试验和微核试验。使用氧化损伤的DNA的可靠测量，关于遗传毒性的结果相对较少，DNA双链断裂(γH2AX测定)和突变。总的来说,有证据表明，口服暴露于颗粒和纤维与动物的遗传毒性有关。
