Size-Resolved Dynamics Of Indoor And Outdoor Fluorescent Biological Aerosol Particles In A Bedroom: A One-Month Case Study In Singapore

This study evaluated the interrelations between indoor and outdoor bioaerosols in a bedroom under a living condition. Two wideband integrated bioaerosol sensors were utilized to measure indoor and outdoor particulate matter (PM) and fluorescent biological airborne particles (FBAPs), which were within a size range of 0.5-20 mu m. Throughout this one-month case study, the median proportion of FBAPs in PM by number was 19% (5%; the interquartile range, hereafter) and 17% (3%) for indoors and outdoors, respectively, and those by mass were 78% (12%) and 55% (9%). According to the size-resolved data, FBAPs dominated above 2 and 3.5 mu m indoors and outdoors, respectively. Comparing indoor upon outdoor ratios among occupancy and window conditions, the indoor FBAPs larger than 3.16 mu m were dominated by indoor sources, while non-FBAPs were mainly from outdoors. The occupant dominated the indoor source of both FBAPs and non-FBAPs. Under awake and asleep, count- and mass-based mean emission rates were 45.9 and 18.7 x 10(6) #/h and 5.02 and 2.83 mg/h, respectively. Based on indoor activities and local outdoor air quality in Singapore, this study recommended opening the window when awake and closing it during sleep to lower indoor bioaerosol exposure.