Size‐resolved dynamics of indoor and outdoor fluorescent biological aerosol particles in a bedroom: A one‐month case study in Singapore

Abstract

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 μm. 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 μm indoors and outdoors, respectively. Comparing indoor upon outdoor ratios among occupancy and window conditions, the indoor FBAPs larger than 3.16 μm 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 × 106 #/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.

Changes in Air Quality during the COVID-19 Lockdown in Singapore and Associations with Human Mobility Trends

“…In addition to the smartphone data we acquired data regarding the Housing and Development Board (HDB) carpark availability using the API provided by the Singaporean Government (HDB, 2020). Approximately 81% of the whole population in Singapore lives in HDB apartments (HDB, 2018;Li et al, 2020), hence this data provides a meaningful estimation of how many Singaporean used their personal vehicle during the lockdown period. We gathered aggregate data on an hourly basis regarding the total number of residential occupied and free car spots across the whole country.…”

Direct-Read Fluorescence-Based Measurements of Bioaerosol Exposure in Home Healthcare

“…Indoor bioaerosol sources are dependent on various factors such as human occupancy, occupant behavior, and extrinsic activities such as vacuuming and cooking, as well as intrinsic activities such as expiratory flow and shedding from the skin and clothing [ 11 , 22 , 23 , 24 , 25 , 26 ]. The presence of humans and types of activities can also impact both the type and concentration of bioaerosols in indoor environments [ 14 , 23 , 24 , 27 , 28 , 29 ]. Human interactions are also able to influence levels of airborne bioaerosol from skin shedding, household materials such as upholstery, flooring, mattresses, and performing activities such as cleaning, vacuuming, and showering [ 14 , 21 , 23 , 26 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ].…”

Loading Rates of Dust and Bioburden in Dwellings in an Inland City of Southern Europe

“…In future studies, the record on opening windows should be included, since the promotion of natural ventilation contributes to the decrease of microbial loads in the indoor air [71]. It was possible to obtain information on the housing typologies and characteristics that most influence microbial contamination, including azole resistance.…”

“…In future studies, the record on opening windows should be included, since the promotion of natural ventilation contributes to the decrease of microbial loads in the indoor air [71].…”