Concentration characteristics of culturable airborne microbes in family homes in Hangzhou, China

This study assessed the concentration characteristics of culturable airborne microbes in 60 family homes with children aged 1–15 years in Hangzhou, southeast China. The concentration of culturable airborne microbes ranged from 314 colony-forming units (CFU)/m3 to 2903 CFU/m3, with a mean value of 873 CFU/m3. The mean fungal concentration (653 CFU/m3) was significantly higher than the mean bacterial concentration of the atmosphere (220 CFU/m3), and the proportion of airborne fungi (73.9%) was significantly higher than that of airborne bacteria (26.1%). Microbial concentrations in family homes with a male child were significantly higher than those in homes with a female child, and there was a negative correlation between microbial concentration and living area per capita in family homes. The mean microbial concentration was highest in summer, followed by spring and autumn, and lowest in winter. This study provides an exposure database of airborne microbes in family homes in southeast China, suggesting that child gender and human occupancy in family homes significantly influence the microbial concentration in the air.