Characteristics of airborne bacteria and fungi in the atmosphere in Ho Chi Minh city, Vietnam - A case study over three years

Abstract

The purpose of this study was to determine and assess airborne microbial characteristics (bacteria and fungi) in Ho Chi Minh City (HCMC), Vietnam, from 2014 to 2016, as well as identify seasonal variation trends. Airborne samples were collected passively and actively from four different environmental sites: the zoo, road, rural, and urban areas. The major bacterial genera identified were Bacillus siamensis, Staphylococcus aureus, Micrococcus varians, and Enterobacteriaceae. Some airborne fungi (Aspergillus sp., Penicillium janthinellum, and Fusarium solani) were found during the wet and dry seasons. In rural and residential areas, airborne bacterial and fungal bioaerosol levels were higher during weekends than weekdays. A linear model illustrated the significant effect of the environmental factors CO2 level, temperature (TEMP), and relative humidity (RH) on both bacterial and fungal counts. There was a positive relationship between microbial sampling types especially between microbial concentration and CO2 level and TEMP (p < 0.05). The linear models explained a certain percent of the variation in bacterial and fungal concentration in terms of CO2, TEMP, and RH on the roadside (Dien Bien Phu – Dinh Tien Hoang intersection), the zoo (Saigon Zoo and Botanical Garden), the residential area, and the rural area. These insights into bacteria and fungi levels can be used to aid future health studies, policy making, and urban planning in HCMC.