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Deposition of hydrophobic and hydrophylic ambient particles in the human respiratory tract
J Aerosol'Scl. Vol. 31, Suppl. l, pp. $508-$509, 2000
Pergamon www.elsevier.com/locate/jaerosci P o s t e r S e s s i o n I, I n t r a p u h n o n a r y
particle deposition and retention
DEPOSITION OF HYDROPHOBIC AND HYDROPHYLIC AMBIENT PARTICLES IN THE HUMAN RESPIRATORY TRACT
G. A. FERRON, E. KARG, C. ROTH and J. HEYDER GSF - National Research Center for Environment and Health, Institute for Inhalation Biology, D-85758 Neuherberg/Munieh, Germany
Keywords: Atmospheric particles, hygroscopic particles, lung deposition AMBIENT PARTICLES A recent field study in Southern Germany (Ferron et al., 1999) revealed that the average size distribution of ambient particles in urban, semi-urban and rural sites are rather similar (Figure 1), whereas the number
"1°4
•,E•
103 102
- t - - Rural ~.-~,~--Semi-urban ". Urban
~" 101 loo ~10-1 10.2 10 -'~
10-I
10 °
particle diameter (I.tm) Figure 1. Mean particle number distributions. concentration N and mass concentration m are rather different (Table 1). At the rural site 65% (f=0.65) of the particles number or mass concentration is bound to hydrophilic particles, and at the urban site 28%. Chromatography and laser-induced mass spectrometry measurements indicated (Busch, 1997) that the major component in hydrophobic particles is carbon (C) and that of the hydrophilic particles is carbon and ammonium sulphate. The growth factor g of the hydrophilic particles due to water vapour adsorption determined by measuring the size of the particles at <5% and 85% relative humidity (ILl-I)was found to be very similar at all sites (Table 1). The particles grew 37% (g=1.37) in diameter at the rural site and 30% at the urban site. Consequently, the carbon and ammonium sulphate content of the particles were very similar. These hydrophilic particles form the background in the environmental aerosol. Their growth was then used to calculate the (NH4)2SO4 mass and total solid mass ratio in these particles. At the rural site 52% (h=0.52) of the content of hydrophilic particles turned out to be (NH4)2SO4, at the urban site 40% (Table 1). PARTICLE GROWTH The RH of the air inspired rises while the air is penetrating into the lungs and approximates a value of 99.5%. Thus hydrophilic particles grow in size when inhaled. Using Raoult's Law, the growth factor at RH of 99.5% can be calculated from the measured value at RH of 85% by
$508
Abstracts of the 2000 European Aerosol Conference
$509
3 3 1 - RH99.5/K99.S g99.5 - 1 = (g85 - 1) 1 - RH85/K85 valid for a constant dissociation constant and no deliquescence point for RH's between 85% and 99.5%. LUNG DEPOSITION The mass of inhaled hydrophobic and hydrophilic ambient particles deposited per hour in the respiratory tract for healthy persons living at rural, semi-urban and urban sites was calculated with a deposition model developed by Ferron et al. (1988). It was assumed that the persons inhaled with a tidal volume of 500 cm 3, at an air flow of 250 cm3s "1. The results for hydrophobic and hydrophilic deposited mass rates are shown in Table I for deposition in the extrathoraeic region (DEE), the bronchial region (DEB) and the alveolar region
Location
N
m
cm -3
lag m -3
g
h
Deposited hydrophilie mass rate (gg h "l)
Deposited hydrophobic mass rate (gtg h -1) DE E
DE B
DE A
DE E
DE B
DE A
Rural
65000
10
0.65
1.37
0.52
0.0
0.30
1.38
0.0
0.10
0.57
Semi-Urban
32000
12
0.48
1.33
0.45
0.0
0.29
1.94
0.0
0.08
0.42
Urban
96000
32
0.28
1.30
0.40
0.0
1.80
7.35
0.0
0.13
0.65
Table 1: Properties and deposited mass rates of ambient particles. (DEA) of the respiratory tract. For comparison the total deposited mass rates in- and excluding the hygroscopic properties of the atmospheric particles are listed in Table 2. When neglecting particle growth the deposition pattern was not seriously affected. Considering other uncertainties in the model calculations the inlrapulmonary growth of ambient particles can be neglected when the deposition of ambient particles in the respiratory tract is estimated.
Location
Deposited mass rate including hygroscopic properties (I.tg h -l)
Deposited mass rate excluding hygroscopic properties (p.g h'l)
DE E
DE B
DE A
DE E
DE B
DE A
Rural
0.0
0.4
2.0
0.0
0.6
2.4
Semi-Urban
0.0
0.4
2.4
0.0
0.6
2.7
Urban
0.0
1.9
8.0
0.0
2.2
8.9
Table 2: Deposited mass rates in- and excluding intrapolmonary hydrophilic particle
~ow~m
Acknowledgement." This work has been supported in part by the Bavarian Ministry for State Development and Environment, Bavarian Climate Research Program BayFORKLIM (G II 4). REFERENCES Busch, B. (1997). Abschluflbericht G4. Bayerische Klimatforschungsprogramm, Munich. Ferron, G A., Karg, E., Busch, B., Heyder, J. (1999). J. AerosolSci. 30, S19-20. Ferron, G A., Kreyling, W. G, Haider, B. (1988). AerosolSci. 19, 611-631.
Pergamon www.elsevier.com/locate/jaerosci P o s t e r S e s s i o n I, I n t r a p u h n o n a r y
particle deposition and retention
DEPOSITION OF HYDROPHOBIC AND HYDROPHYLIC AMBIENT PARTICLES IN THE HUMAN RESPIRATORY TRACT
G. A. FERRON, E. KARG, C. ROTH and J. HEYDER GSF - National Research Center for Environment and Health, Institute for Inhalation Biology, D-85758 Neuherberg/Munieh, Germany
Keywords: Atmospheric particles, hygroscopic particles, lung deposition AMBIENT PARTICLES A recent field study in Southern Germany (Ferron et al., 1999) revealed that the average size distribution of ambient particles in urban, semi-urban and rural sites are rather similar (Figure 1), whereas the number
"1°4
•,E•
103 102
- t - - Rural ~.-~,~--Semi-urban ". Urban
~" 101 loo ~10-1 10.2 10 -'~
10-I
10 °
particle diameter (I.tm) Figure 1. Mean particle number distributions. concentration N and mass concentration m are rather different (Table 1). At the rural site 65% (f=0.65) of the particles number or mass concentration is bound to hydrophilic particles, and at the urban site 28%. Chromatography and laser-induced mass spectrometry measurements indicated (Busch, 1997) that the major component in hydrophobic particles is carbon (C) and that of the hydrophilic particles is carbon and ammonium sulphate. The growth factor g of the hydrophilic particles due to water vapour adsorption determined by measuring the size of the particles at <5% and 85% relative humidity (ILl-I)was found to be very similar at all sites (Table 1). The particles grew 37% (g=1.37) in diameter at the rural site and 30% at the urban site. Consequently, the carbon and ammonium sulphate content of the particles were very similar. These hydrophilic particles form the background in the environmental aerosol. Their growth was then used to calculate the (NH4)2SO4 mass and total solid mass ratio in these particles. At the rural site 52% (h=0.52) of the content of hydrophilic particles turned out to be (NH4)2SO4, at the urban site 40% (Table 1). PARTICLE GROWTH The RH of the air inspired rises while the air is penetrating into the lungs and approximates a value of 99.5%. Thus hydrophilic particles grow in size when inhaled. Using Raoult's Law, the growth factor at RH of 99.5% can be calculated from the measured value at RH of 85% by
$508
Abstracts of the 2000 European Aerosol Conference
$509
3 3 1 - RH99.5/K99.S g99.5 - 1 = (g85 - 1) 1 - RH85/K85 valid for a constant dissociation constant and no deliquescence point for RH's between 85% and 99.5%. LUNG DEPOSITION The mass of inhaled hydrophobic and hydrophilic ambient particles deposited per hour in the respiratory tract for healthy persons living at rural, semi-urban and urban sites was calculated with a deposition model developed by Ferron et al. (1988). It was assumed that the persons inhaled with a tidal volume of 500 cm 3, at an air flow of 250 cm3s "1. The results for hydrophobic and hydrophilic deposited mass rates are shown in Table I for deposition in the extrathoraeic region (DEE), the bronchial region (DEB) and the alveolar region
Location
N
m
cm -3
lag m -3
g
h
Deposited hydrophilie mass rate (gg h "l)
Deposited hydrophobic mass rate (gtg h -1) DE E
DE B
DE A
DE E
DE B
DE A
Rural
65000
10
0.65
1.37
0.52
0.0
0.30
1.38
0.0
0.10
0.57
Semi-Urban
32000
12
0.48
1.33
0.45
0.0
0.29
1.94
0.0
0.08
0.42
Urban
96000
32
0.28
1.30
0.40
0.0
1.80
7.35
0.0
0.13
0.65
Table 1: Properties and deposited mass rates of ambient particles. (DEA) of the respiratory tract. For comparison the total deposited mass rates in- and excluding the hygroscopic properties of the atmospheric particles are listed in Table 2. When neglecting particle growth the deposition pattern was not seriously affected. Considering other uncertainties in the model calculations the inlrapulmonary growth of ambient particles can be neglected when the deposition of ambient particles in the respiratory tract is estimated.
Location
Deposited mass rate including hygroscopic properties (I.tg h -l)
Deposited mass rate excluding hygroscopic properties (p.g h'l)
DE E
DE B
DE A
DE E
DE B
DE A
Rural
0.0
0.4
2.0
0.0
0.6
2.4
Semi-Urban
0.0
0.4
2.4
0.0
0.6
2.7
Urban
0.0
1.9
8.0
0.0
2.2
8.9
Table 2: Deposited mass rates in- and excluding intrapolmonary hydrophilic particle
~ow~m
Acknowledgement." This work has been supported in part by the Bavarian Ministry for State Development and Environment, Bavarian Climate Research Program BayFORKLIM (G II 4). REFERENCES Busch, B. (1997). Abschluflbericht G4. Bayerische Klimatforschungsprogramm, Munich. Ferron, G A., Karg, E., Busch, B., Heyder, J. (1999). J. AerosolSci. 30, S19-20. Ferron, G A., Kreyling, W. G, Haider, B. (1988). AerosolSci. 19, 611-631.