Proceedings: Indoor Air 2002
ON THE FORMALDEHYDE AND VOCS CONCENTRATION
DIFFERENCE AMONG HOUSES IN APARTMENT HOUSE JUST
AFTER THE CONSTRUCTION
K Ikeda1*, M Shiotsu1 and S Sato2
1
The Institute of public Health Dept. of Architectural Hygiene and Housing Engineering,
Tokyo JAPAN
2
TOYOTA CENTRAL R&D LABS., INC. Human Factors Div. Nagoya, Japan
ABSTRACT
Measurement of formaldehyde and VOCs concentration 88 apartment houses for single persons
which was build in September 2001 were conducted. We investigate the concentration
difference among the houses.
INDEX TERMS
IAQ, HCHO, VOCs, Brand-new apartment house, Field measurement
INTRODUCTION
Indoor air pollution problems, so-called “sick house syndrome (SHS)” is now drawing very
strong public attention, in Japan. Definition of the SHS is not yet reaching a public consensus,
but it is deemed as one of the IAQ problems caused by chemical air pollutants, such as
formaldehyde and VOCs, emitted from plywood, wall paper, grew and other building materials
in side residential buildings. Significant improvements in air-tightness of building envelop
resulting from advancement of building construction techniques are the other provable cause of
SHS.
Japanese construction industries try to use the materials not emitting chemicals reflecting these
social concerns. Ministry of Construction (MOC) of Japanese Government recently established
an administrative system to indicate qualities of the building materials of constructed houses so
that the consumers can make their brand-new house selection better.
Nationwide large-scale surveys were conducted. For example survey over the 1,500 houses by
Ikeda, K. and Park J.S. (2000) and measurements on the 5,000 homes by MOC were conducted
in 2001. However these measurements were conducted for the houses which were just available
at those time, and systematic information like a relation between indoor air concentration and
building related factors, such as kinds of the building materials, ventilation rates of the
buildings, life style of the occupants, furniture and appliances introduced in the buildings and so
forth, is therefore not enough.
VOC concentration measurements using a passive monitor method were conducted in 88
brand-new “one-room” flats for the bachelors, which were contained in an apartment block, just
before moving into the building. Investigations on the relationship between indoor
concentration and location of the flats were made
*
Contact author email: [email protected]
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Proceedings: Indoor Air 2002
OUTLINES OF THE SURVEY
Hoses surveyed
88 “one-room” flats for bachelors which were contained in a ten-storied apartment block built
in Tokyo, and is completed on middle of June, 2001. Total floor area of the flat is about 25m2.
Mechanical ventilation system is equipped in the kitchen and is operated basically in the
occasion of cooking.
Measuring Instruments Used
Passive sampler:
-DSD-DNPH cartridge (manufactured by Spelco Co.Ltd.) for HCHO (Cat.No282221- U)
-Passive tube (by Shibata Kagaku Co. Ltd) for VOCs (CODE8015-066)
Monitoring of HCHO concentration:
-Fuel Cell type HCHO monitor (by JMS Co. Ltd.)
Temperature and Humidity:
-Thermo-hygrometer (by Tabai-Espec Co. Ltd) TERMO RECORDER RS-10
Ventilation rate:
-Photo-acoustic method (by Bruel and Kjear Co. Ltd.) Single Gas Monitor Model 3425
Measurement Procedures
Samplers were placed in a point 1.2m high above the floor, and in the middle of a living room of
each flat hanged at lamp code in a middle of each flat7s living room. Double samplings were
conducted in the house 105 and 605.
Indoor HCHO concentrations were monitored at several places including living room, entrance,
toilet, kitchen, and other places on the necessity, using grab-sampling type monitor.
Indoor temperature and humidity measurements were conducted in house 1001, 905, 601, 605,
101 and 105, and those of outdoors were made at corridor in front of house 605.
Ventilation rates were measured in house 404 using tracer gas decay method. SF6 gas was used
as tracer. We assumed ventilation rate of each room was not changed much since the rooms
were not occupied yet. We therefore measure ventilation rate only in one house.
Measurement Schedule
Measurement schedule is shown in figure 1.
Day 1 (Aug. 1, ’01): All the doors of furniture were open and vent was closed in the evening.
Day 2 (Aug. 2, ’01): Passive sampling tubes were placed on the each location in the morning.
Temperature and humidity were monitored using Thermo-hygrometer on the occasion of
setting the sampler tubes. Temperature and humidity measurements were also conducted 4 to 6
hours later the placement of the sampling tubes along with HCHO monitor by grab-sampling
method. Day 3 (Aug. 3, ’01): In the morning Samplers were recovered after the 24 hours
exposure to the indoor air. Indoor HCHO monitoring and temperature and humidity
measurements were also conducted. Entering of the construction people into the houses during
measurements was restricted.
RESULTS
Circumstances of the project building
It was cloudy both on 1st and 2nd and the morning of 3rd day of August. It was windy on 2nd day,
and construction work, which caused a little bit smell of tar, was conducted in shaft spaces.
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Proceedings: Indoor Air 2002
Temperature and Humidity
Results of temperature and humidity are shown in figure 2 and 3.
Wed.Aug.,1 '01
Thr.Aug.,2
Fri.Aug.,3
Cloudy
Cloudy
Cloudy accasionally fair
hour
6
12
18 24 6 12 18 24 6 12 18
Monitoring of temparature and humid(7poits)
24
setting passive sampler
Open the funitur's
door and close
openings for vet
Monitorring of
Temp. and Humid
Monitored temp. and Humid
average over all the houses
Temp.F29.35
HumidF60.1
Gab monitoring HCHO,
Temp. and humid
Monitored temp. and Humid
average over all the houses
Temp.F29.21
HumidF60.7
Monitored temp. and
Humid average over all the
houses
TempF28.60
Figure 1. Schedule of the Measurements
Time(hour)
7:15
3:20
11:10
Time(hour)
23:25
19:30
average of humidity over 6
houses(1001,905,605,601,105,
101)
15:35
12:00
8:00
4:00
0:00
20:00
16:00
12:00
8:00
4:00
0:00
20:00
20
3:50
outdoor
outdoor
20:00
25
11:40
Relative Humidity(%)
)
Temparaturei
30
7:45
90
80
70
60
50
40
30
20
10
0
average of temparature over 6
houses(1001,905,605,601,105,101)
23:55
35
Figure 2. Results of temperature measurements. Figure 3. Results of humidity measurements
Outdoor temperature and humidity averaged over 8:00 p.m. of August 1 to 12:00 p.m. of
August 3 were 26.9 oC and 68.5%. Maximum and minimum values over of this period were
31.8 oC, 77% and 24.5 oC , 50％ respectively. Indoor temperature and humidity averaged over
same period were 28.6 oC and 66.6%. Maximum and minimum values of this period were 29.1
o
C , 68% and 27.7 oC , 68％ respectively. Indoor temperature and humidity in each room were
kept constant while those of outdoors were varying considerably．Temperature and humidity
difference among rooms were within 5 oC and 10% respectively, and is enough small compared
to outdoor temperature and humidity fluctuation as we expected.
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Proceedings: Indoor Air 2002
Ventilation Rates
Ventilation rates in the house 404 were considerably low, 0.02 ach, which means ventilation rate
(air leakage rate) of the house was 1.25 m3/h (=25m2x2.5mx0.02) and was very little amount.
We assume that high aldehyde concentration that is sometime seen in certain house, comes from
this extremely reduced ventilation although aldehyde emission from the building materials was
not much since designer pay very much attention to use low emission materials. We therefore
recommend that it is necessary to ventilate more, using mechanical ventilation systems and
opening the vent and window, in order to reduce aldehyde concentration.
Formaldehyde and acetaldehyde concentrations
Figure 4 shows the results of indoor carbonyl concentration measurements. Figures in an upper
row of the each column show formaldehyde concentrations in ppb, while those in lower row
show acetaldehyde concentration in ppb. Average values over each floor are shown in hatched
column. Average value of formaldehyde concentration over all the houses was 213.41ppb
(standard deviation: 111.92ppb), and those of maximum and minimum were 496.01ppb
(recorded in house 607) and 47.33ppb (in house 203) respectively. Results obtained from 11
houses out of 88 (12.5%) were exceeded guideline value established by MHLW, 80ppb.
Average value of acetaldehyde over all the houses was 48.89ppb (standard deviation: 27.41ppb),
and those of maximum and minimum were 117.99ppb (recorded in house 807) and 8.45ppb (in
house 102) respectively. Results obtained from 29 houses out of 88 (33%) were exceeded
guideline value established by MHLW, 30ppb.
Average of
each elevation
188.29 10th floor
52.74
237.81 9th floor
66.38
203.97 8th floor
61.42
243.71 7th floor.
63.58
226.93 6th floor
56.95
190.71 5th floor
49.45
281.27 4th floor
51.85
156.90 3rd floor
24.18
76.56 2nd floor
17.08
106.45 1st floor
25.37
144.50 276.20 163.47 168.99
40.62
78.43
46.61
45.29
327.90 182.90 372.81
67.62 259.60
90.34
52.22 105.80
17.17
71.53
198.37 252.05 157.10 208.37
76.49
56.93
84.58
42.99
61.18
17.83
174.13 375.40 252.90 172.43
83.94
42.76 104.60
62.97
44.00
21.18
250.12
81.11 310.68 265.83 139.88
69.16
19.20
62.69
76.75
28.78
276.11 186.44
83.28 217.00 209.83
71.42
52.14
16.36
57.90
46.42
147.95 237.10 380.35 359.69 205.31
22.35
52.61
69.31
63.12
31.81
82.76 199.32 192.52 153.00 344.60
12.69
36.68
25.93
21.42
44.59
54.22 135.40
47.33
69.27
95.64
11.02
30.96
9.62
16.71
23.75
96.20
54.50 103.14 171.96
48.61
25.97
8.45
20.40
46.65
9.93
House 1 House 2 House 3 House 4 House 5
Average of each row 175.23 198.04 206.36 185.42 162.65
44.33
51.99
46.27
45.02
32.87
U pper row :Form aldehyde concentration(ppb)
Low er row :A cetaldehyde aoncentration(ppb)
366.49
89.99
229.03 457.90 350.92
65.34 117.99
97.90
365.31 175.73 206.25 324.22 202.24
98.64
51.13
51.83 105.10
44.67
257.71 496.01 231.01 181.58 141.01
67.45 103.74
55.88
39.68
30.45
284.79 335.68 323.66 148.56 351.25
68.81
72.00
77.38
30.45
91.20
415.21 310.07 204.03 328.23 276.25
82.17
43.26
36.88
25.66
48.01
298.66 398.84 418.23 222.57 409.36
57.44
72.35
75.08
44.86
59.70
112.57 125.83
86.06 120.17
95.50
28.66
28.70
23.25
28.97
22.55
77.95
77.15
71.58 134.13
54.36
18.93
18.15
15.50
29.95
10.71
House 6 House 7 House 8 House 9 House 10
267.52 297.15 236.47 208.49 218.57
64.16
63.42
54.21
43.52
43.90
Figure 4. Result of Carbonyl compound concentrations by passive sampling method
Table 1. Comparison of the double sampling results obtained at each location of indoor and
outdoor houses
Formaldehyd 1
(ppb)
2
Difference(ppb)
acetaldehyde 1
(ppb)
2
Difference(ppb)
1Fl. outdoor 6Fl. outdoor
8.75
4.88
6.30
3.51
2.45
1.37
4.28
1.60
2.92
0.97
1.36
0.62
101
96.20
95.21
0.99
25.97
25.23
0.74
252
105
48.61
39.36
9.25
9.93
8.02
1.91
601
250.12
309.65
59.53
69.16
85.98
16.82
605
139.88
215.31
75.42
28.78
49.18
20.40
905
259.60
360.68
101.08
71.53
101.09
29.56
1001
144.50
233.75
89.25
40.62
66.59
25.97
Proceedings: Indoor Air 2002
Table 1 shows the results of comparison between two samples obtained at the points where
double samplings were made. The double sampling points were selected 2 from outdoors and 6
from indoors. Coupled data were not deferent much.
Figure 5 shows a correlation between 24 hours average concentrations obtained from passive
sampling method and average concentration of 2 data. One was obtained from the grab
sampling at 2 to 4 hours later beginning of the 24 passive sampling and the other was obtained
from the grab sampling at the time when the passive samplers were recovered.
Passive HCHO concentratio(ppb)
1000.00
800.00
600.00
400.00
200.00
0.00
0.00
0.20
0.40
0.60
0.80
1.00
Grab monitoring HCHO concentration(ppm)
Figure 5. Correlation between passive method and average concentration of grab sampling
VOC concentrations
Table 2 shows statistical values of VOC concentrations measured in each site. Table 3 Shows
Correlation coefficient of VOCs
Table 2. Result of VOC concentration
MIBK
n¿ cmetylisob toluen butylacet ethylbe Xyle
ododecan
utylketone e
ate
nzene nes styrene xylene pinene e
ppb
ppb
ppb
ppb ppb
ppb
ppb
ppb
ppb
Averag
e
Standar
d error
Median
standar
d
minimu
maximu
sample
number
detectio
n lower
limit
0.055
0.118
0.031
0.016 0.019
0.068
0.010
0.008
0.010
0.005
0.040
0.008
0.093
0.002
0.025
0.001 0.001
0.013 0.017
0.005
0.058
0.001
0.009
0.001
0.006
0.001
0.008
0.036
0.015
0.143
0.073
0.022
0.315
0.017
0.008
0.076
0.008 0.011
0.004 0.003
0.046 0.052
0.044
0.009
0.190
0.005
0.003
0.019
0.005
0.002
0.026
0.007
0.001
0.037
45
88
64
82
79
85
40
66
56
43
0
24
6
9
3
48
22
32
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Proceedings: Indoor Air 2002
Table 3. Correlation coefficient of VOCs
MIBK
Forma
n¿ acetald
dodeca
ethylbe
oXylenes styrene
cmetylisob toluene butyla
ldehyd
ehyde
nzene
xylene pinene ne
utylketone
e
cetate
0.00
0.22 0.06
0.07
0.13 0.27 0.08 0.09 0.07
1.00 0.88
Formaldehy
-0.02
0.20 0.04
0.05
0.14 0.27 0.14 0.10 0.14
1.00
acetaldehyd
MIBK
cmetylisobut
ylketone
toluene
nethylbenzen
Xylenes
styrene
o-xylene
¿ -pinene
dodecane
1.00
0.47
0.46
0.35
0.35
0.38
0.55
0.19
0.04
1.00
0.37
1.00
0.25
0.15
1.00
0.21
0.10
0.04
1.00
0.36
0.15
0.12
-0.03
1.00
0.13
0.03
-0.19
-0.41
-0.20
1.00
0.09
0.06
0.02
-0.11
-0.18
-0.11
1.00
-0.10
-0.14
-0.11
0.42
-0.07
-0.23
-0.15
1.00
DISCUSSION
As shown in figure 4 and table 1, correlation between formaldehyde and acetaldehyde was quite
high. Correlation cofficient reached 0.88. The correlation coefficient of formaldehyde and other
VOCs were, on the other hand, not high or almost no relation. Formaldehyde and acetaldehyde
concentrations averaged over each floor of 1st to 3rd were considerably low compared to those
averaged over each floor of 4th to 8th. This may be related closely to construction schedule of
the building. Correlation coefficient between 24 hour average concentrations and grab
sampling concentration is about 0.37, and was not high.
CONCLUSION
1. 24hour average formaldehyde concentration over whole houses was 213ppl, and those of
maximum were 496ppb. 11out of 88 houses were exceeded indoor formaldehyde guideline set
by MHLW of Japanese government, 80ppb.
2. 24hour average acetaldehyde concentration over whole houses was 49ppb and those of
maximum were 112ppb. 29 of 88houses were exceeded Japanese guideline, 30ppb.
3. Correlation between formaldehyde and acetaldehyde was quite high.
4. Correlation between formaldehyde and VOCs were not high.
ACKNOWLEDGEMENT
We express special thank to owner of the building and manger of the construction site, who
were very kind to corporate our measurements.
REFERENCES
Ikeda, K. Park J.S, 2000. A DATABASE ON FORMALDEHYDE CONCENTRATION IN
RESIDENCES, Proceedings of Healthy Buildings 2000.Vol.1, 413-418, 2000
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