Airborne pollution has become a leading cause of global death in industrialized cities and the exposure to environmental pollutants has been demonstrated to have adverse effects on human health. Among the pollutants, particulate matter (PM) is one of the most toxic and although its exposure has been more commonly correlated with respiratory diseases, gastrointestinal (GI) complications have also been reported as a consequence to PM exposure. Due to its composition, PM is able to exert on intestinal mucosa both direct damaging effects, (by reaching it either via direct ingestion of contaminated food and water or indirect inhalation and consequent macrophagic mucociliary clearance) and indirect ones via generation of systemic inflammation. The relationship between respiratory and GI conditions is well described by the lung-gut axis and more recently, has become even clearer during coronavirus disease 2019 (COVID-19) pandemic, when respiratory symptoms were associated with gastrointestinal conditions. This review aims at pointing out the mechanisms and the models used to evaluate PM induced GI tract damage.

中文翻译：

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胃肠组织作为污染暴露的“新”目标

空气污染已成为工业化城市全球死亡的主要原因，并且已证明暴露于环境污染物会对人类健康产生不利影响。在污染物中，颗粒物 (PM) 是毒性最大的物质之一，尽管其暴露与呼吸系统疾病更常见相关，但也有报道称，PM 暴露会导致胃肠道 (GI) 并发症。由于其成分，PM 能够对肠黏膜产生直接破坏作用（通过直接摄入受污染的食物和水或间接吸入和随后的巨噬性黏液纤毛清除）和通过产生全身炎症而间接破坏。肺肠轴很好地描述了呼吸和胃肠道疾病之间的关系，最近，在 2019 年冠状病毒病 (COVID-19) 大流行期间，当呼吸道症状与胃肠道疾病相关时，这一点变得更加清晰。本综述旨在指出用于评估 PM 引起的胃肠道损伤的机制和模型。