A good indoor air quality (IAQ) is preferred for a healthy and safe indoor environment especially for children since they are more susceptible to the effects from indoor pollutants. Most of indoor air pollution researches focus on the health effect on the children but they eliminate the possibility of how the environmental factors and daycare characteristics could contribute to this problem. This study investigates the concentration level of PM10 and its relationship with environmental factors and daycare centers characteristics and two different sampling sites, representing residential and near roadside. Gravimetrical method was used in order to present spatiotemporal analysis utilizing descriptive analysis, Pearson Correlation and Coefficient of Divergence (COD) treatments of data. The average indoor concentration in Taska Penyayang 1 Malaysia (TP1M, representing residential setting) were 105.97 ° 40.06 μg/m3 indoor and 50.77 ° 30.85 μg/m3 outdoor. Taska Penyayang Permata (TPP), represented near roadside setting were 59.88 ° 18.53 μg/m3 and 69.09 ° 23.54 μg/m3 indoor and outdoor, respectively. PM10 variations at TP1M was observed to be originated from indoor/local strong sources and was minimally influenced by weather parameters and outdoor infiltration. Infiltration of pollutants occurred at TP1M, showed by large IOR (above unity) while exfiltration of pollutants governed at TPP, indicated by low IOR and insignificant COD values between all of its micro-location. Natural ventilation as practiced by TPP may also be the reason of very much lower levels of PM10 concentration, evidenced by strong positive correlation between number of occupants and inverse correlation between number of activities. Lower frequency of activities accumulates PM10, contributing to its higher level. In contrast, persistent closed-windows and doors may contribute to inadequate ventilation and accumulated air pollutants, as observed at TP1M. This has been evident by higher COD correlation, indicating similar sources of PM10 at micro-environments with outdoor air.
