Pawit ChaivisitAngélique FontanaSabine GalindoCaroline StrubThitiworn ChoosongDuangporn KantachoteThunwadee Tachapattaworakul SuksarojUniversité de MontpellierMahidol UniversityPrince of Songkla UniversityOffice of Disease Prevention and Control2019-08-232019-08-232018-05-01EnvironmentAsia. Vol.11, No.2 (2018), 53-66190617142-s2.0-85059704939https://repository.li.mahidol.ac.th/handle/20.500.14594/45885© 2018, Thai Society of Higher Eduation Institutes on Environment. All rights reserved. The airborne bacteria and fungi distribution characteristics and their relationship with environmental factors in the natural ventilation system were investigated in a university hospital, Thailand. The 672 samples were collected in the outpatient and inpatient departments (OPDs and IPDs). The levels of carbon dioxide (CO 2 ), temperature, relative humidity, and the number of people were also recorded during sampling. The characteristics, size distribution, and concentration of bioaerosols were not affected by the tropical humid seasons but its levels were dependent on some environmental factors. The indoor and outdoor concentration (I/O) ratio and multiple regression analysis indicated the level of indoor airborne bacteria and fungi were affected by outdoor origins but mainly contributed by population occupied and humidity inside. There is no difference of dominant genera cultured from dry and wet season samples. However the respiratory factions of these bioaerosols were more than 60% when most of them detected with particle size range of 2.1-3.3 µm. The results of this study can provide fundamental information about indoor air quality improvement and management in university hospitals that are located in the humid tropical zone of Thailand.Mahidol UniversityEnvironmental SciencePharmacology, Toxicology and PharmaceuticsArticleSCOPUS10.14456/ea.2018.22