Density of bacterial particles cultivable in the inside and outside air of kindergartens in Birjand, Iran during 2019

Background and Aims: Bioaerosols are airborne particles that contain bacteria, viruse, and fungi. Human show different reactions to bioaerosols. This study aimed to determine the density of bacterial particles cultivable in the inside and outside air of kindergardens in Birjand, Iran. Materials and Methods: This study was performed based on a descriptive-analytical and cross-sectional research approach. Birjand was divided into five regions based on their geographical location, and six kindergardens were randomly selected. The sampling was performed in the morning shift from all six selected kindergartens. Additionally, triptic soy agar was used as the culture medium, and the sampling was performed at a flow rate of 28.3 L/Min for 35 min at a distance of 0.8 to 1 M above the ground in the center of each class. The data were analyzed in SPSS software (version 16) through the Mann-Whitney and Kruskal-Wallis statistical tests. A p-value less than 0.05 was considered statistically significant. Results: According to the results, the highest mean bacterial and microbial load and suspended particles were obtained at 3.83±8.04 CFU/m3 and 196.13±382.54 CFU/m3 in February and March, respectively. There was no significant relationship among bacterial density, suspended particles, and temperature (P>0.05). However, a significant relationship was observed between the bacterial density and total suspended particles (P<0.05). There was also a significant relationship between the amount of suspended particles (PM1, PM2.5, PM10) and the environment inside and outside the kindergardens (P<0.05). Conclusion: It is possible to determine the concentration of bacterial contamination in terms of quantity, type of identified species, and the amount of airborne particles to prevent the adverse health effects.