Microbial Counts and Particulate Matter Levels in Indoor Air Samples Collected from a Child Home-Care Center in Bangkok, Thailand
Pipat Luksamijarulkul MSc*, Yuwadee Ratthanakhot MSc**, Pisit Vatanasomboon MSc***
Affiliation : * Department of Microbiology, Faculty of Public Health, Mahidol University, Bangkok, Thailand ** Wachiraphuket Hospital, Muang, Phuket, Thailand *** Department of Environmental Health Science, Faculty of Public Health, Mahidol University, Bangkok, Thailand
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, fifty-
two 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
