This work investigated the personal exposure to indoor particulate matters using the intake fraction metric and provided a possible way to trace the particle inhaled from an indoor particle source. A turbulence model validated by the particle measurements in a room with underfloor air distribution (UFAD) system was used to predict the indoor particle concentrations. Inhalation intake fraction of indoor particles was defined and evaluated in two rooms equipped with the UFAD, i.e., the experimental room and a small office. According to the exposure characteristics and a typical respiratory rate, the intake fraction was determined in two rooms with a continuous and episodic (human cough) source of particles, respectively. The findings showed that the well-mixing assumption of indoor air failed to give an accurate estimation of inhalation exposure and the average concentration at return outlet or within the overall room could not relate well the intake fraction to the amount of particle emitted from an indoor source.
DockeryDWPopeCAXuX. An association between air pollution and mortality in six United-States cities. N Engl J Med1993; 329(24): 1753–1759.
2.
PopeCABatesDVRaizenneME. Health effects of particulate air pollution: time for reassessment?Environ Health Perspect1995; 103(5): 472–480.
3.
KlepeisNENelsonWCOttWR. The National Human Activity Pattern Survey (NHAPS): a resource for assessing exposure to environmental pollutants. J Expo Anal Environ Epidemiol2001; 11(3): 231–252.
4.
Holmberg S and Li Y. Non-passive particle dispersion in a displacement ventilated room-a numerical study. In: Proceedings of the 6th International Conference on Air Distribution in Rooms, KTH, Stockholm, Sweden, 14–17 June, 1998, vol. 1, pp.467–473.
5.
Holmberg S, Hokkanen J, Jarmyr R, et al. The influence of air supply and exhaust locations on ventilation efficiency and contaminant exposures in rooms. In: Proceedings of the 8th International Conference on Indoor Air Quality and Climate, Edinburgh, Scotland, 8–13 August 1999, vol. 2, pp.18–23.
6.
HolmbergSChenQ. Air flow and particle control with different ventilation systems in a classroom. Indoor Air2003; 13(2): 200–204.
BennettDHMckoneTEEvansJS. Defining intake fraction. Environ Sci Technol2002; 36(9): 207A–211A.
9.
MarshallJDTeohSKNazaroffWW. Intake fraction of nonreactive vehicle emissions in US urban areas. Atmos Environ2005; 39(7): 1363–1371.
10.
LuoZLiYNazaroffWW. Intake fraction of nonreactive motor vehicle exhaust in Hong Kong. Atmos Environ2010; 44(15): 1913–1918.
11.
LaiACKThatcherTLNazaroffWW. Inhalation transfer factors for air pollution health risk assessment. J Air Waste Manag Assoc2000; 50(9): 1688–1699.
12.
NazaroffWW. Inhalation intake fraction of pollutants from episodic indoor emissions. Build Environ2008; 43(3): 269–277.
13.
RussoJSKhalifaHE. CFD assessment of intake fraction in the indoor environment. Build Environ2010; 45(9): 1968–1975.
14.
HeQBNiuJLGaoNP. CFD study of exhaled droplet transmission between occupants under different ventilation strategies in a typical office room. Build Environ2011; 46(2): 397–408.
15.
HusseinTKorhonenHHerrmannE. Emission rates due to indoor activities: indoor aerosol model development, evaluation, and applications. Aerosol Sci Technol2005; 39(11): 1111–1127.
16.
YeungLLToWM. Size Distributions of the aerosols emitted from commercial cooking processes. Indoor Built Environ2008; 17(3): 220–229.
MorawskaLJohnsonGRRistovskiZD. Size distribution and sites of origin of droplets expelled from the human respiratory trace during expiratory activities. Aerosol Sci2009; 40: 256–269.
19.
KobayashiNChenQ. Floor-Supply Displacement ventilation in a small office. Indoor Built Environ2003; 12(4): 281–291.
20.
LimTSSchaeferLKimLT. Energy benefit of the underfloor air distribution system for reducing air-conditioning and heating loads in buildings. Indoor Built Environ2012; 21(1): 62–70.
21.
MazejMButalaV. Investigation in the characteristics of the personal ventilation using computational fluid dynamics. Indoor Built Environ2012; 21(6): 749–771.
22.
Adams WC. Measurement of breathing rate and volume in routinely performed daily activities. Contract No. A033–205. Sacramento, CA, Air Resources Board, 1993.
23.
HusseinTKulmalaM. Indoor aerosol modeling: basic principles and practical applications. Water Air Soil Poll2008; 8(1): 23–34.
24.
LiuCZhaoBZhangY. The influence of aerosol dynamics on indoor exposure to airborne DEHP. Atmos Environ2010; 44(16): 1952–1959.
GaoJGaoFSZhaoJN. Applicability of traditional and a newly modified RNG turbulence model to the indoor thermally stratified flow. J Harbin Inst Technol2007; 14: 255–258.
27.
ZhangZChenQ. Comparison of the Eulerian and Lagrangian methods for predicting particle transport in enclosed spaces. Atmos Environ2007; 41(25): 5236–5248.
28.
LiAAhmadiG. Dispersion and deposition of spherical particles from point sources in a turbulent channel flow. Aerosol Sci Technol1992; 16(4): 209–226.
29.
RizkMAElghobashiSE. The motion of a spherical particle suspended in a turbulent flow near a plane wall. Phys Fluids1985; 28(3): 806–817.
NazaroffWWCassGR. Mathematical modeling of indoor aerosol dynamics. Environ Sci Technol1989; 23(2): 157–166.
32.
HindsWC. Aerosol Technology: Properties, Behavior, and Measurement of Airborne Particles, 2nd edn. New York: Wiley, 1999.
33.
CroweCTSharmaMPStockDE. The particle-source-in-cell model for gas droplet flows. ASME J Fluids Eng1977; 99(6): 325–332.
34.
ZhangZChenQ. Experimental measurements and numerical simulations of particle transport and distribution in ventilated rooms. Atmos Environ2006; 40(18): 3396–3408.
35.
ZhuSKatoSYangJH. Study on transport characteristics of saliva droplets produced by coughing in a calm indoor environment. Build Environ2006; 41(12): 1691–1702.
36.
MorawskaL. Droplet fate in indoor environments, or can we prevent the spread of infection?Indoor Air2006; 16(5): 335–347.
