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

Background and Aim: Bioaerosols are airborne particles that contain bacteria, viruses and fungi. Human reaction to bioaerosols is very different. The aim of this study was performed to determine the density of bacterial particles cultivable in the air of inside and outside kindergartens in Birjand. Materials and Methods: This descriptive-analytical cross-sectional study was performed. Birjand city was divided into 5 regions based on geographical location and 6 kindergartens were randomly selected. Sampling was done in the morning shift from 6 selected kindergartens.The culture medium used was triptic soy agar for bacteria. Sampling was performed at a flow rate of 28.3 L/Min in 35 minutes at a distance of 0.8 to 1 M above the ground in the center of each class. Statistical analysis was performed using SPSS (Version.16) software and Mann-Whitney and Kruskal-Wallis statistical tests and a significance level (P<0.05) was considered. Results: The results showed that the highest mean bacterial microbial load in February was (3.83±8.04) CFU/m3 and suspended particles in March (196.13±382.54) CFU/m3. There was no significant relationship between bacterial density with suspended particles and temperature (P>0.05). There was a significant relationship between bacterial density and total suspended particles (P<0.05). There was a significant relationship between the amount of suspended particles (PM1, PM2.5, PM10) with the environment inside and outside the kindergarten (P<0.05). Conclusion: From the findings of this study, the concentration of bacterial contamination in terms of quantity and type of identified species and the amount of airborne particles can be identified to prevent adverse health effects.