Objective: To assess the microbial count (bacteria and fungi) and particulate matter with sizes less than 10 μm (PM10) level in indoor air of a child home-care center in Bangkok.
Material and Method: A total of 287 air samples were collected from the indoor air of twenty households which were part of a child home-care center to assess bacterial and fungal counts (212 samples) and PM10 levels (66 samples). Additionally, fiftytwo and twenty-six outdoor air samples were collected to compare microbial count and PM10 levels.
Results: It was found that means + standard deviation (SD) for bacterial and fungal counts in the child home-care center were 527.8 + 230.9 cfu/m3 and 514.6 + 256.7 cfu/m3, respectively (those in outdoor air samples were 264.6 + 179.7 cfu/m3 and 308.7 + 217.3 cfu/m3, respectively). The mean + SD of PM10 level was 125.1 + 48.0 μg/m3 (that in outdoor air samples was 120.1 + 66.9 μg/m3). When compared with the level for the indoor air quality guideline, 47.2% and 47.6% of total air samples had bacterial and fungal counts higher than the recommended levels and 47.0% of total air samples had PM10 levels higher than the recommended level.
Conclusion: The present study found that about 47% of total air samples collected from the child home-care center had bacterial and fungal counts and PM10 levels higher than the recommended levels. These results may affect the health of a child who spends most of his/her time in this center. Some intervention or preventive endeavors should be undertaken, including periodic cleaning and maintenance of the ventilation systems and adoption of a regular schedule for room cleaning should be implemented.

Keywords: Indoor air quality, Microbial count, PM10, Child home-care center