Indoor emissions of total and fluorescent supermicron particles during HOMEChem

Abstract

Inhalation of particulate matter is associated with adverse health outcomes. The fluorescent portion of supermicron particulate matter has been used as a proxy for bioaerosols. The sources and emission rates of fluorescent particles in residential environments are not well understood. Using an ultraviolet aerodynamic particle sizer (UVAPS), emissions of total and fluorescent supermicron particles from common human activities were investigated during the HOMEChem campaign, a test-house investigation of the chemistry of indoor environments. Human occupancy and activities, including cooking and mopping, were found to be considerable sources of indoor supermicron fluorescent particles, which enhanced the indoor particle concentrations by two orders of magnitude above baseline levels. The estimated total (fluorescent) mass emission rates for the activities tested were in the range of 4-30 (1-11) mg per person-meal for cooking, and 0.1-4.9 (0.05-4.7) mg/h for occupancy and mopping. Model calculations indicate that, once released, the dominant fate of coarse particles (2.5-10 micrometer in diameter) was deposition onto indoor surfaces, allowing for the possibility of subsequent resuspension and consequent exposures over durations much longer than the ventilation time scale. Indoor coarse particle deposition would also contribute to soiling of indoor surfaces.

Wildfire Smoke Impacts on Indoor Air Quality Assessed Using Crowdsourced Data in California

“…We also observed peaks of indoor PM2.5 exceeding the outdoor PM2.5 even on the most polluted days. These peaks typically lasted between 1 hour and 4 hours, which match well with the characteristics of cooking/cleaning peaks, reported in studies such as Patel et al and Tian et al (17,18). Fig.…”

“…Decomposition of Indoor PM2. 5 In addition to infiltration of PM2.5 from outdoors, cooking, cleaning and resuspension are the main sources of indoor PM2.5 (17,18,42). Prior to assessing the amount of indoor PM2.5 resulting from infiltration of wildfire smoke, we first identified and removed the events (peaks) caused by indoor sources based on the magnitude and duration of indoor PM2.5 peaks.…”

Indoor black carbon and brown carbon concentrations from cooking and outdoor penetration: insights from the HOMEChem study

“…Detailed PM concentration results from HOMEChem can be observed in Patel et al 66 and Tian et al. 67 Dominant BC peaks were observed twice, at ~10:00 am, when the oven was first turned on to ~200 ºC and again starting at ~3:50 pm, when two scented candles were lit inside the house.…”

Fates and spatial variations of accumulation mode particles in a multi-zone indoor environment during the HOMEChem campaign

“…[41][42][43][44][45] Deposition measurements made by Tian et al (2020) for deposition of supermicron particles during the HOMEChem campaign seamed together well with our observations and are used here to present a more meaningful analysis of the mechanisms controlling deposition. 46 In order to understand the intricacies of deposition of particles in indoor environments, we probed different mechanisms controlling deposition using two models. First, the widely-used indoor deposition model developed by Lai & Nazaroff (2000) is useful for understanding the particle contribution to deposited lms on surfaces.…”