Association among polydisperse aerodynamic size of bioaerosols, biodiversity and urbanization in kindergartens

Tzu-Hsien Lin; Ying-Hsiang Chou; Tzu-Yu Hsu; Chun-Hui Hung; Chane-Yu Lai

doi:10.1016/j.chemosphere.2024.142333

Association among polydisperse aerodynamic size of bioaerosols, biodiversity and urbanization in kindergartens

Chemosphere. 2024 May 15:359:142333. doi: 10.1016/j.chemosphere.2024.142333. Online ahead of print.

Authors

Tzu-Hsien Lin¹, Ying-Hsiang Chou², Tzu-Yu Hsu³, Chun-Hui Hung⁴, Chane-Yu Lai⁵

Affiliations

¹ Department of Public Health, China Medical University, Taichung, Taiwan. Electronic address: seanthlin@gmail.com.
² Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan; Department of Radiation Oncology, Chung Shan Medical University Hospital, Taichung, Taiwan; Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan. Electronic address: hideka.chou@gmail.com.
³ Department of Occupational Safety and Health, Chung Shan Medical University, Taichung, Taiwan. Electronic address: nt33012705a@gmail.com.
⁴ Department of Occupational Safety and Health, Chung Shan Medical University, Taichung, Taiwan. Electronic address: a7917919@yahoo.com.tw.
⁵ Department of Occupational Safety and Health, Chung Shan Medical University, Taichung, Taiwan; Department of Occupational Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan. Electronic address: cylai511@gmail.com.

PMID: 38759806
DOI: 10.1016/j.chemosphere.2024.142333

Abstract

The aerodynamic sizes of bioaerosols may significantly affect their behaviors, respiratory deposition and biodiversity. The respirable bacterial size, biodiversity, and human-associated bacteria (HAB) related bioaerosols were evaluated at three kindergartens in Taiwan. Kindergartens A, B, and C were in urban, semi-urban, and rural areas, respectively. A six-stage viable Andersen cascade impactor was used to collect bioaerosols and to determine their size distributions. The geometric mean diameter (GMD), geometric standard deviation (GSD), heat maps, and uniformity were used to evaluate the association of bacteria characteristics. A BD Phoenix-100 automated interpretation system was used to identify the airborne bacteria species. The results revealed that 1425 colonies of the sampled airborne bacteria contained 63 species in 29 genera, and overall, 63.0% were HABs. The most abundant phylum was Actinobacteria (56.6 ± 22.2%) and Firmicutes (31.6 ± 22.3%), and from the taxonomic analysis, both airborne Micrococcus and the Staphylococcus aureus are the dominant genus. All the bacteria aerodynamic particle size distributions were polydisperse distributions. The heat map and uniformity analysis had revealed most of the sampled bioaerosols distributed between 1.1-3.3 μm, and most of the polydisperse airborne Streptococcus spp. had a size in the respirable range, due to urbanization, they have potentially contributed to respiratory risk in the kindergartens. The Shannon diversity index (H) and inverse Simpson diversity index (D) of the bioaerosols in urban kindergarten were negatively correlated with GMD and GSD. The Pearson correlations revealed that the kindergarten in the rural area, with a higher temperature, a lower relative humidity, and a lower CO₂ concentration than the others, tended to have the largest H and D values (P < 0.05). Multiple and stepwise regression revealed that bioaerosol aerodynamic size was statistically significantly correlated with H (P = 0.001) and D values (P = 0.002). This study sheds light on the characteristics of bioaerosols and their associations with microbiome.

Keywords: Bioaerosol; Biodiversity; Human-associated bacteria; Kindergarten; Size distribution.