10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
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Impact of Household Daily Activities on Indoor Air Quality
Estela Vicente, Fernanda Oduber, Carlos Blanco-Alegre, Ana Isabel Calvo, Amaya Castro, Roberto Fraile, Teresa Nunes, CÉLIA ALVES, University of Aveiro
Abstract Number: 574 Working Group: Indoor Aerosols
Abstract Household activities, such as cooking and cleaning, are known to generate considerable amounts of particulate matter indoors. In this study, the impact of four standard vacuum cleaners (washable filter bagless vacuum, wet vacuum, bag vacuum and a HEPA filter equipped robot) and two flat irons (steam iron and a steam iron with boiler) on indoor particulate matter levels was studied. The measurements were performed in León (Spain), in a house living room trying to reproduce the everyday conditions in late autumn (all the doors and windows were kept closed due to the cold weather outside - situation 1). Additionally, the particulate levels generated during steam ironing were also characterized while keeping the room doors opened and the windows closed (situation 2). On average, 45 min measurements were conducted during vacuum cleaning and 3 and half hours during ironing. After each household activity, the sampling continued until the restoration of particle concentration to the original level. Background indoor air measurements were also performed. A real-time laser photometric instrument (TSI, DustTrak DRX 8533) was used to record particulate matter concentration over time. Submicrometer particle number concentrations were measured using a Scanning Mobility Particle Sizer (SMPS, TSI Incorporated), which gives real time size distributions and number concentrations in the range from 7.64 to 310.6 nm. Simultaneous sampling with a PM10 high volume air MCV (model CAV-A/mb) instrument for gravimetric quantification was carried out. The equipment was operated at a flow of 30 m3/h. Particulate samples were collected on pre-weighed 150 mm quartz fibre filters (Pallflex®) for gravimetric and chemical analyses. The gravimetric quantification was performed with a microbalance (XPE105 DeltaRange®, Mettler Toledo). After gravimetric determinations, thermo-optical analysis of PM10 filters was performed to obtain the carbonaceous content.
Regarding vacuum cleaning, the highest increase of PM10 concentrations and total particle number concentration was observed using the wet vacuum, 14.5 fold and more than 40-fold compared to background concentration, respectively. A 2-fold increase in PM10 mass over the background level was observed during the use of the HEPA filter equipped robot. PM2.5 to PM10 ratios ranged from 0.43 (HEPA filter equipped robot) to 0.81 (wet vacuum). As regards the total number of particles, the readings were in the same order of magnitude, before, during and after the vacuum operation. Total carbon accounted from 9.0 ± 1.8 (wet vacuum) to 45.5 ± 4.1 (HEPA filter equipped robot) % wt. of the PM10 mass.
Average PM10 mass concentration in situation 1while steam ironing, without (191 ± 16 µg/m3) and with boiler (180 ± 20 µg/m3), increased more than 15 and 14 times compared to background concentration, respectively. Steam ironing under situation 2 conditions still increased the PM10 concentration 4.8 times (60 ± 17 µg/m3). The lowest PM2.5/PM10 ratio (0.87) was observed during steam ironing under situation 2 conditions. Total particle number concentrations were from one to almost two orders of magnitude higher during ironing than prior to the start of the activity. Total carbon accounted for 30.4 ± 5.1 (steam ironing, situation 1), 51.8 ± 8.2 (steam ironing, situation 2) and 38.8 ± 3.1 (boiler steam ironing, situation 1) % wt. of the PM10 mass.