Microorganisms are an important aspect of the environment which have significant effects on human health. Children are more vulnerable to the effects of microbial pollutants, pathogens and allergens. Microbial components of indoor air cannot be overemphasized due to its vastness and ubiquitous nature. This is a cross sectional comparative study which analysed microbiome in 10 preschools according to their level of exposure to outdoor air pollutant sources using amplicon sequencing technique. A total of 20 dust samples were collected from indoor and outdoor environment and analysed for the presence of bacteria and fungi. A detailed questionnaire was used to assess the respiratory health status of the respondents. Indoor air quality was assessed by measuring the level of particulate matter (PM_2.5 and PM₁₀), temperature, relative humidity, air velocity, and CO₂. Exposed area recorded higher level of PM₁₀ and CO₂ (p <0.05) while temperature, relative humidity and air velocity were higher in the comparative area (p <0.05). Health symptoms were significantly higher in exposed area for cough, eczema and allergy symptoms (p <0.05). Predominant bacteria species includes Acinetobacter_radioresistens, Acinetobacter_seifertii, Lactobaccillus_iners, Pseudomonas_B_luteola, and Franconibacter_pulveris while predominant fungi species includes Rhodosporidioboluc_fluvialis, Rhodotorula_kratochvilovae, Aspergillus_penicilloides, Aspergillus_gracilis, Curvularia_sorghina, Eupenidiella_venezuelensis, Rhodosporidiobolus_ruineniae, Bipolaris_papendorfii and Curvularia_lunata. Cough symptom was strongly associated with PM₁₀ (AOR =1.27), carpeting (AOR =1.62), Cladosporium dominicanum (AOR =2.12) and Aureobasidium gracilis (AOR =2.04). Eczema was strongly associated with keeping furry pet (AOR =5.46) and Rhodotorula_toruloides (1.02). Allergy was strongly associated with PM₁₀ (AOR =3.23), Megasporoporia_bannaensis (AOR =1.43) and Malassezia_restricta (AOR =2.10). Preschools located close to outdoor air pollutants were more exposed to pollutants and microbiome from indoor and outdoor sources. Health symptoms were significantly associated with air pollutants, therefore proper measures should be implemented to mitigate the exposure to microbiome, infiltration of outdoor air pollutants and health effects on children.

微生物是环境的重要组成部分，对人类健康具有重要影响。儿童更容易受到微生物污染物、病原体和过敏原的影响。室内空气中的微生物成分无论怎样强调都不为过，因为它的数量巨大且无处不在。这是一项横断面比较研究，使用扩增子测序技术根据 10 所幼儿园暴露于室外空气污染物源的程度对微生物组进行了分析。从室内和室外环境中总共采集了 20 个灰尘样本，并分析了细菌和真菌的存在情况。使用详细的问卷来评估受访者的呼吸健康状况。通过测量颗粒物（PM _2.5和 PM ₁₀）水平、温度、相对湿度、空气流速和 CO ₂来评估室内空气质量。暴露区域的 PM ₁₀和 CO ₂水平较高( p  <0.05)，而对比区域的温度、相对湿度和空气流速较高 ( p  <0.05)。暴露区域的咳嗽、湿疹和过敏症状的健康症状明显较高（p  <0.05）。主要细菌种类包括Acinetobacter_radioresistens、Acinetobacter_seifertii、Lactobaccillus_iners、Pseudomonas_B_uteola和Franconibacter_pulveris，而主要真菌种类包括Rhodosporidioboluc_fluvialis、Rhodotorula_kratochvilovae、Aspergillus_penicilloides、Aspergillus_gracilis、Curvularia_sorghina、Eupenidiella_ven ezuelensis、Rhodosporidiobolus_ruineniae、Bipolaris_papendorfii和Curvularia_lunata。_{咳嗽症状与 PM 10} (AOR =1.27)、地毯 (AOR =1.62)、Cladosporium dominicanum (AOR =2.12) 和Aureobasidium gracilis (AOR =2.04)密切相关。湿疹与饲养毛茸茸的宠物 (AOR =5.46) 和红酵母(1.02)密切相关。_{过敏与 PM 10} (AOR =3.23)、Megasporoporia_bannaensis (AOR =1.43) 和Malassezia_restricta (AOR =2.10)密切相关。靠近室外空气污染物的幼儿园更容易接触室内和室外的污染物和微生物组。健康症状与空气污染物显着相关，因此应采取适当措施减轻微生物组暴露、室外空气污染物渗透以及对儿童健康的影响。