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DFs emissions from crematories in Japan
Chemosphere 40 (2000) 575±586
PCDDs/DFs emissions from crematories in Japan Nobuo Takedaa,*, Masaki Takaokaa, Takeshi Fujiwaraa, Hisayuki Takeyamab, Shoji Eguchib a
Environmental Engineering, Graduate School of Engineering, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan b Japan Society of Environmental Crematory, 6-3 Miyamoto, Kawasaki-ku, Kawasaki 210-0004, Japan Received 10 March 1999; accepted 21 May 1999
Abstract Concentrations of PCDDs and PCDFs in emission gases from 10 crematories were measured. The relationship between PCDDs/DFs and several factors such as structure, equipment and operational state of the crematory is discussed. Furthermore, emission of PCDDs/DFs from all crematories in Japan is estimated. The following results are obtained: (1) total concentration of PCDDs/DFs was 2.2±290 ng/N m3 , whose TEQ concentration was 0.0099±6.5 ng TEQ/N m3 ; (2) total concentration of PCDFs was higher than that of PCDDs; (3) T4CDFs was the highest in the homologue pattern and 2,3,7,8-T4CDF was the highest in the isomer pattern; (4) emission of PCDDs/DFs was the largest in the ®rst 20 min of cremation; (5) concentration of PCDDs/DFs was related to the existence of a secondary combustion chamber and a dust collector, and the ratio of the numbers of main and secondary combustion chambers; (6) total emission of PCDDs/DFs from crematories in Japan was estimated to be 8.9 g TEQ/yr. Ó 2000 Elsevier Science Ltd. All rights reserved. Keywords: PCDDs/DFs; Crematory; Combustion; Emission gas; Gas sampling
1. Introduction Recently, dioxin emissions from refuse incinerators have become a serious problem in Japan. Although there are studies to estimate the quantity of dioxins emitted from industrial waste incinerators, steel manufacturing and automobiles (Hiraoka and Okajima, 1994), only a few studies have been carried out on dioxin emissions from crematories. Eguchi et al. (1996) reported the concentration of dioxins from a crematory in Japan to be 0.14±2.56 ng TEQ/N m3 . This is less than the concentration of dioxins from crematories in Germany at 8 ng TEQ/N m3 as reported by Hutzinger and Fiedler (1993). A working group of a sub-
*
Corresponding author.
committee of the German federal state pollution control committee investigated concentration of dioxins in 1994 for 13 crematories which are selected from 100 crematories in Germany, and reported that the concentration of dioxins from crematories was 0.1±14.4 ng TEQ/N m3 and almost all of them were more than 1 ng TEQ/N m3 (The Working Group of Subcommittee, 1993). Since more than 99% of dead bodies are cremated in 1607 crematories in Japan, it is necessary to investigate many crematories of various types to estimate the quantity of dioxins emitted from crematories. In this research, concentrations of PCDDs and PCDFs in emission gases from 10 crematories were measured. The relationship between dioxins and several factors such as structure, equipment and operational state of the crematory is discussed. Furthermore, total emission of PCDDs/DFs from crematories in Japan is estimated.
0045-6535/00/$ - see front matter Ó 2000 Elsevier Science Ltd. All rights reserved. PII: S 0 0 4 5 - 6 5 3 5 ( 9 9 ) 0 0 2 3 2 - 5
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N. Takeda et al. / Chemosphere 40 (2000) 575±586
2. Custom of funeral in Japan Funeral rite usually depends on religion and custom of a country. In Japan, 99% (in 1995) of dead bodies are cremated and the percentage is the highest in the world (Shimazaki, 1997). Since the bone ash of a dead person is collected by his/her bereaved family at the end of cremation in Japan, the dead bodies must be burned and cooled down in a furnace, one by one. So that, a crematory site involves multiple furnaces (48 furnaces in a crematory is the largest in Japan) and the furnace is operated not continuously but batch-wise. Capacity of each furnace is small and treatment equipment of the emission gas is simple. Especially, old-fashioned crematories remaining widely in Japan involve no equipment for gas treatment. For this reason, concentration of dioxins from crematories should be investigated. The typical cremation procedure performed in Japan is as follows: 1. A secondary burner is ignited to warm up a secondary combustion chamber. 2. A con containing a dead body is placed into a main combustion chamber. 3. A main burner is ignited to burn the con and dead body. 4. The secondary burner is turned o because calories from the dead body and the fuel for the main burner are enough to keep temperature of the secondary combustion chamber high. 5. The main burner is turned o after everything with exception of bones are burned. 6. The main combustion chamber is cooled down by blowing air into it. 7. The bereaved family collect the bone ash. By considering this procedure, it is decided that igniting the secondary burner and turning o the main burner are regarded as start and end of gas sampling. 3. Measurement method of PCDDs/DFs concentration in emission gas Table 1 shows the 10 crematories studied in this work. The number of cremations in these crematories occupied 4% of the number of total cremations in Japan. The construction or improvement year of the crematory is from 1985 onward. In crematories A, C and J, a secondary combustion chamber is connected to three or four main combustion chambers so that the ¯ue gases from more than two main combustion chambers go into the secondary combustion chamber simultaneously. In order to take account of overlapped cremation in multiple furnaces during measurement, the eective number of cremations was calculated by dividing the sum of the cremation
period in all of main combustion chambers by the average cremation period for a dead body. Flue gas was sampled throughout a cremation, i.e., from igniting the secondary burner to turning o the main burner (only gas sampling for HCl was terminated at 20 min after ignition of the secondary burner). During the sampling period, concentrations of dust, O2 , CO, HCl and NOx were measured, and temperatures of the main/secondary combustion chambers and ¯ue gas were observed. Moreover, age and sex of the dead bodies, and accompanied equipment in cons were recorded. Concentrations of PCDDs/DFs were measured according to the manual of the Ministry of Health and Welfare of Japan and the USEPA method 23. GC/MS (Auto Spec ULTIMA by Micro Mass) with a column DB-5 was used to measure concentrations of PCDDs/ DFs, and a column DB-225 was used when the separation eciency of 2,3,7,8-T4CDF when using the column DB-5 was insucient. Equations to calculate PCDDs/ DFs concentration are listed in Table 2. 4. Results and discussion 4.1. Results of PCDDs/DFs Measured concentrations of PCDDs/DFs (12% O2 normalized) and the toxic equivalent concentrations are shown in Tables 3 and 4, respectively. Total concentration of PCDDs/DFs was 2.2±290 ng/N m3 , whose TEQ concentration was 0.0099±6.5 ng TEQ/N m3 . The total concentration of PCDFs was higher than that of PCDDs in all samples except of crematory A. 4.1.1. The total and the TEQ concentration of PCDDs/ DFs The relationship between the total and the TEQ concentrations of PCDDs/DFs is shown in Fig. 1, and the regression line for the refuse incinerator is also shown using a dotted line for comparison. The ratio of the two concentrations for crematories was about 2.1%, and it was larger than that for refuse incinerators, 1.6%. The reason for this is that a greater amount of T4CDFs which have a large TEF are included in PCDFs. 4.1.2. Homologue and isomer patterns Homologue patterns of crematory C and A are shown in Figs. 3 and 4, respectively, and an isomer pattern of crematory C is shown in Fig. 2. The concentration of T4CDFs was highest in the homologue pattern of PCDFs and the concentration lowered as the number of bonded chlorine atoms increased. Although the magnitude of PCDDs was not uniform, two homologue patterns of PCDDs were identi®ed: one has high concentration of T4CDDs (Fig. 3) and the other has a mountain shape (Fig. 4). The former pattern is
a
Sampling period (min)
Gas sampling 3
67 M 75 1
83
M 72 1
F 92 1.5
64
F 70 2.4
s s 83 F 72
M 52 1
94
F 93 1
s ´ 77
Town gas ´
s s Induced 1
s(´)a ´ Induced 4 Kerosene s
D
C
s(´) means the crematory C has a secondary chamber but does not use it.
Dead body Sex Age The number of cremations
Sampling period (min) Dead body Sex Age The number of cremations
M 85 1
F 93 3
Gas sampling 2
s s 47
s s 82 M 68
Town gas s
Kerosene s
M 70
s s Induced 1
s s Induced 3
B
A
Code of crematory
Secondary chamber Dust collector Ventilation The number of main chambers connected to a secondary chamber Burner fuel TemperaMain ture Secondary Flue gas Gas Sampling period sampling 1 (min) Dead body Sex Age The number of cremations
Table 1 Con®guration of crematory and sampling condition
F 72 1
57
F 86 1
s ´ 64
Kerosene s
s s Induced 1
E
M 74 1
64
M 82 1
66
M 62 1
s s 63
Kerosene s
s s Induced 1
F
F 89 1.3
58
M 57 1.2
68
M 56 1.1
s s 67
Kerosene ´
s ´ Induced 1
G
M 23 1
114
M 85 1
s ´ 75
A heavy oil ´
s ´ Induced 1
H
F 61 1
78
M 61 1
s ´ 90
Kerosene ´
s ´ Induced 1
I
F 74 2.4
92
F 101 3
´ ´ 117
F 89
M 72
A heavy oil ´
s ´ Induced 3
J
N. Takeda et al. / Chemosphere 40 (2000) 575±586 577
578
N. Takeda et al. / Chemosphere 40 (2000) 575±586
Table 2 De®nition of concentration calculationa Measured concentration Cs
analized quantity intake of emission gas
Limit of quantification LOQ
detection limit DL intake of emission gas
O2 12% normalized concentration C
21 ÿ 12 Cs 21 ÿ O2 concentration Os
Toxic equivalent concentration C ´ international toxic equivalent factor (TEF) a
If whole concentrations of the isomers are lower than LOQ, then concentration taking account of Ôlower than LOQÕ LOQ 12 TEF.
considered to be characteristic of crematory. From patterns of 17 kinds of toxic isomers that include chlorine atoms at least at 2, 3, 7 and 8 positions, it was found that the concentration of 2,3,7,8-T4CDF is the largest. The same homologous and isomer patterns are found in almost all crematories, and this suggests that the patterns are typical for cremations and or do not depend on the condition of the dead body, age, sex, funeral materials, and so on. 4.1.3. Time trend of concentration To identify the time trend of PCDDs/DFs concentrations, the ¯ue gas was sampled during 0±20, 20±40, and 40 min ± the end, respectively, in crematory H. It was assumed that the con and other funeral materials caught ®re in the ®rst period, and easily combustible parts and other parts of the dead body started to burn in the second and the last periods, respectively. The TEQ concentration was the greatest in the ®rst period (0.027), which was followed by the second (0.023), and the third (0.018). Although the dierences among these concentrations were small, it can be said that the total TEQ concentration in the ®rst 20 min is higher than that in the second 20 min. This is similar to the result shown by Eguchi et al. (1996). It is considered that burning of the con and other funeral materials caused high concentrations of PCDDs/DFs. 4.1.4. Age and sex of a dead body Dierences in the concentration by age and sex of the dead body could not be identi®ed, but the number of samples was not enough to draw any conclusion. 4.2. PCDDs/DFs and components in emission gas 4.2.1. Dust concentration High concentration of dust was detected in the crematories having no dust collector. Black smoke emitted from a stack and an excessively high concentration of CO was observed in such crematories. The relation be-
tween dust concentration and total concentration of PCDDs/DFs is shown in Fig. 5. One crematory has over 700 mg/N m3 , but total concentration of PCDDs/DFs was not very high (27 ng/N m3 ). The concentration was low in the crematories whose dust concentration was less than 50 mg/N m3 . Thus, it is considered that emission of PCDDs/DFs is reduced by dust collectors. 4.2.2. Temperature of secondary combustion chamber In every crematory, the temperature in the main combustion chambers increased rapidly up to 800°C in the ®rst 10 min after start up. The relationship between the temperature in the secondary combustion chamber at a steady state and total concentration of PCDDs/DFs is shown in Fig. 6. The concentration was low in the crematory whose temperature was above 850°C. 4.2.3. O2 , CO, NOx and HCl concentrations Charts of O2 , CO and NOx concentrations during the sampling period of crematories C and H are shown in Figs. 7 and 8, respectively. Because air is blown into a duct which is connected to an exit of the secondary combustion chamber to dilute and cool down combustion gas, O2 concentration was higher (about 15±20%) than that in the refuse incinerator. O2 concentration depends on the crematory: O2 concentration in crematory C was constantly high but the concentration changed with time in crematory H. Since addition of large amount of air makes concentrations of PCDDs/DFs lower than the detection limit, total amount of PCDDs/DFs that is calculated by multiplying gas volume and the concentration is estimated lower than the actual amount. Therefore, an appropriate method to measure the concentrations for the crematory should be considered. In some crematories, it was found that concentration of CO increases and decreases quickly soon after ignition of main/secondary burners and extinction of the secondary burner. Especially, CO concentration in
Total (PCDDs+PCDFs)
PCDFs
PCDDs
PCDDs/PCDFs isomer and homologue (ng/N m3 )
96
Total PCDFs 190
1.3 32 1.4 2.8 26 2.5 2.0 0.17 2.4 20 7.9 1.4 14 4.1
2,3,7,8-T4CDF T4CDFs 1,2,3,7,8-P5CDF 2,3,4,7,8-P5CDF P5CDFs 1,2,3,4,7,8-H6CDF 1,2,3,6,7,8-H6CDF 1,2,3,7,8,9-H6CDF 2,3,4,6,7,8-H6CDF H6CDFs 1,2,3,4,6,7,8-H7CDF 1,2,3,4,7,8,9-H7CDF H7CDFs O8CDF
98
Total PCDDs
82
49
0.82 21 0.91 1.2 14 0.85 0.88 ± 0.85 7.7 2.5 0.54 4.8 1.7
34
0.16 4.3 0.40 6.8 0.37 0.88 0.74 11 4.0 7.7 4.3
2
6.5
5.5
0.30 5.5 ± ± ± ± ± ± ± ± ± ± ± ±
0.96
± 0.96 ± ± ± ± ± ± ± ± ±
1
0.20 8.4 0.97 20 1.0 2.6 2.1 29 13 25 16
1
2,3,7,8-T4CDD T4CDDs 1,2,3,7,8-P5CDD P5CDDs 1,2,3,4,7,8-H6CDD 1,2,3,6,7,8-H6CDD 1,2,3,7,8,9-H6CDD H6CDDs 1,2,3,4,6,7,8-H7CDD H7CDDs O8CDD
B
A
Crematory
Table 3 Concentrations of PCDDs/DFs in emission gas of crematories
42
34
1.1 20 ± 1.6 9.2 ± ± ± ± 2.2 1.8 ± 1.8 ±
8.0
± 2.2 ± ± ± ± ± 2.8 1.7 3.0 ±
2
290
220
7.4 140 4.3 5.4 64 2.7 2.7 ± 2.1 17 2.9 ± 2.9 ±
70
1.1 31 1.4 19 ± ± 1.7 15 2.4 4.7 ±
1
C
230
180
6.5 120 3.3 4.0 45 ± 2.1 ± ± 7.4 2.7 ± 2.7 ±
53
0.94 28 ± 10 ± ± ± 12 ± 2.2 ±
2
3.5
3.5
0.28 2.8 ± ± 0.62 ± ± ± ± ± ± ± ± ±
±
± ± ± ± ± ± ± ± ± ± ±
1
D
7.3
6.9
0.24 6.0 ± ± 0.90 ± ± ± ± ± ± ± ± ±
0.41
± 0.41 ± ± ± ± ± ± ± ± ±
2
20
19
0.49 15 ± ± 4.0 ± ± ± ± ± ± ± ± ±
0.89
± 0.89 ± ± ± ± ± ± ± ± ±
1
E
18
18
0.47 13 ± ± 4.3 ± ± ± ± ± ± ± ± ±
0.31
± 0.31 ± ± ± ± ± ± ± ± ±
2
2.8
2.5
0.13 2.0 ± ± 0.42 ± ± ± ± ± ± ± ± ±
0.33
± 0.33 ± ± ± ± ± ± ± ± ±
1
F
3.1
2.7
0.089 1.4 ± 0.16 0.76 ± ± ± ± 0.27 0.25 ± 0.25 ±
0.47
± 0.20 ± 0.12 ± ± ± 0.15 ± ± ±
2
2.2
2.1
0.099 1.7 ± ± 0.37 ± ± ± ± ± ± ± ± ±
0.091
± 0.091 ± ± ± ± ± ± ± ± ±
3
N. Takeda et al. / Chemosphere 40 (2000) 575±586 579
a
14
Total PCDFs 19
0.41 6.8 0.31 0.48 4.2 0.47 0.30 ± ± 1.9 0.88 ± 0.88 ±
2,3,7,8-T4CDF T4CDFs 1,2,3,7,8-P5CDF 2,3,4,7,8-P5CDF P5CDFs 1,2,3,4,7,8-H6CDF 1,2,3,6,7,8-H6CDF 1,2,3,7,8,9-H6CDF 2,3,4,6,7,8-H6CDF H6CDFs 1,2,3,4,6,7,8-H7CDF 1,2,3,4,7,8,9-H7CDF H7CDFs O8CDF
5.4
Total PCDDs
31
22
0.53 11 0.40 0.88 6.6 0.48 0.41 ± 0.35 2.5 0.88 ± 1.4 ±
8.6
± 1.8 0.23 2.2 ± ± 0.40 2.2 0.75 1.6 0.75
2
3
66
42
0.69 19 0.69 1.7 14 1.1 0.87 ± 1.1 4.7 2.1 0.49 4.1 0.75
24
± 5.4 ± 7.5 0.47 0.62 1.00 6.9 1.9 3.4 1.2
15
9.2
0.27 8.1 ± ± 1.1 ± ± ± ± ± ± ± ± ±
6.1
± 6.1 ± ± ± ± ± ± ± ± ±
1
± 1.1 ± 1.1 ± ± ± 1.2 0.62 1.2 0.73
1
2,3,7,8-T4CDD T4CDDs 1,2,3,7,8-P5CDD P5CDDs 1,2,3,4,7,8-H6CDD 1,2,3,6,7,8-H6CDD 1,2,3,7,8,9-H6CDD H6CDDs 1,2,3,4,6,7,8-H7CDD H7CDDs O8CDD
Ha
G
Crematory
4.7
4.4
0.23 3.9 ± ± 0.51 ± ± ± ± ± ± ± ± ±
0.28
± 0.28 ± ± ± ± ± ± ± ± ±
2
4.6
4.5
0.18 4.0 ± ± 0.55 ± ± ± ± ± ± ± ± ±
0.092
± 0.092 ± ± ± ± ± ± ± ± ±
3
In H-1, H-2, H-3 gas was sampled between start ± 20, 20±40, 40 min ± end of a cremation, respectively.
Total (PCDDs+PCDFs)
PCDFs
PCDDs
PCDDs/PCDFs isomer and homologue (ng/N m3 )
Table 3 (Continued)
4.2
3.7
0.16 3.2 ± 0.097 0.56 ± ± ± ± ± ± ± ± ±
0.48
± 0.48 ± ± ± ± ± ± ± ± ±
4
8.2
7.8
0.45 5.7 ± ± 1.4 ± ± ± ± 0.76 ± ± ± ±
0.37
± 0.37 ± ± ± ± ± ± ± ± ±
1
I
22
21
0.60 10 0.67 0.91 6.9 ± ± ± ± 2.3 0.95 ± 0.95 ±
1.5
0.13 0.72 ± ± ± ± ± 0.79 ± ± ±
2
27
26
1.1 20 0.30 0.35 4.1 0.38 ± ± ± 0.75 0.33 ± 0.33 ±
0.99
0.084 0.99 ± ± ± ± ± ± ± ± ±
1
J
47
41
1.7 30 0.60 0.88 6.8 0.29 0.33 ± 0.31 2.8 0.62 0.14 1.1 0.28
5.3
0.16 3.2 0.11 0.92 0.050 0.064 0.15 0.73 0.17 0.30 0.15
2
580 N. Takeda et al. / Chemosphere 40 (2000) 575±586
Total (PCDDs+PCDFs)
PCDFs
PCDDs
PCDDs/PCDFs isomer and homologue (ng TEQ/N m3 )
0.20 0.037 0.088 0.074 0.040 0.0043
0.49 0.10 0.26 0.21 0.13 0.016 1.4
Total PCDDs
0.085 0.088 ± 0.085 0.025 0.0054 0.0017
0.25 0.20 0.017 0.24 0.079 0.014 0.0041 2.4
Total PCDFs 3.8
0.046 0.61
0.072 1.4
1.6
1.0
0.082
0.13
2,3,7,8-T4CDF T4CDFs 1,2,3,7,8-P5CDF 2,3,4,7,8-P5CDF P5CDFs 1,2,3,4,7,8-H6CDF 1,2,3,6,7,8-H6CDF 1,2,3,7,8,9-H6CDF 2,3,4,6,7,8-H6CDF H6CDFs 1,2,3,4,6,7,8-H7CDF 1,2,3,4,7,8,9-H7CDF H7CDFs O8CDF
0.60
0.16
0.2
2,3,7,8-T4CDD T4CDDs 1,2,3,7,8-P5CDD P5CDDs 1,2,3,4,7,8-H6CDD 1,2,3,6,7,8-H6CDD 1,2,3,7,8,9-H6CDD H6CDDs 1,2,3,4,6,7,8-H7CDD H7CDDs O8CDD
0.030
0.030
±
± ±
± ± ± ±
± ±
0.030
±
±
±
± ± ±
±
±
1
1
2
B
A
Crematory
0.96
0.94
±
0.018 ±
± ± ± ±
± 0.82
0.11
0.017
±
0.017
± ± ±
±
±
2
Toxic equivalent concentrations (TEQ) of PCDDs/DFs in emission gas of crematories
Table 4
6.5
4.5
±
0.029 ±
0.27 0.27 ± 0.21
0.21 2.7
0.74
2.0
±
0.024
± ± 0.17
0.72
1.1
1
C
4.0
3.1
±
0.027 ±
± 0.21 ± ±
0.17 2.0
0.65
0.94
±
±
± ± ±
±
0.94
2
0.028
0.028
±
± ±
± ± ± ±
± ±
0.028
±
±
±
± ± ±
±
±
1
D
0.024
0.024
±
± ±
± ± ± ±
± ±
0.024
±
±
±
± ± ±
±
±
2
0.049
0.049
±
± ±
± ± ± ±
± ±
0.049
±
±
±
± ± ±
±
±
1
E
0.047
0.047
±
± ±
± ± ± ±
± ±
0.047
±
±
±
± ± ±
±
±
2
0.013
0.013
±
± ±
± ± ± ±
± ±
0.013
±
±
±
± ± ±
±
±
1
F
0.091
0.091
±
0.0025 ±
± ± ± ±
± 0.080
0.0089
±
±
±
± ± ±
±
±
2
0.0099
0.0099
±
± ±
± ± ± ±
± ±
0.0099
±
±
±
± ± ±
±
±
3
N. Takeda et al. / Chemosphere 40 (2000) 575±586 581
a
3
± ± 0.040 0.0075 0.00075
± ± ± 0.0062 0.00073 0.0070
Total PCDDs
0.048 0.041 ± 0.035 0.0088 ± ±
0.047 0.030 ± ± 0.0088 ± ± 0.38
Total PCDFs 0.39
0.020 0.44
0.016 0.24
0.81
0.65
0.053
0.041
2,3,7,8-T4CDF T4CDFs 1,2,3,7,8-P5CDF 2,3,4,7,8-P5CDF P5CDFs 1,2,3,4,7,8-H6CDF 1,2,3,6,7,8-H6CDF 1,2,3,7,8,9-H6CDF 2,3,4,6,7,8-H6CDF H6CDFs 1,2,3,4,6,7,8-H7CDF 1,2,3,4,7,8,9-H7CDF H7CDFs O8CDF
0.17
0.12
±
1.5
1.3
0.00075
0.021 0.0049
0.11 0.087 ± 0.11
0.034 0.84
0.069
0.23
0.0012
0.019
0.047 0.062 0.100
±
±
0.027
0.027
±
± ±
± ± ± ±
± ±
0.027
±
±
±
± ± ±
±
±
1
2 ±
1 ±
2,3,7,8-T4CDD T4CDDs 1,2,3,7,8-P5CDD P5CDDs 1,2,3,4,7,8-H6CDD 1,2,3,6,7,8-H6CDD 1,2,3,7,8,9-H6CDD H6CDDs 1,2,3,4,6,7,8-H7CDD H7CDDs O8CDD
Ha
Crematory
G 2
0.023
0.023
±
± ±
± ± ± ±
± ±
0.023
±
±
±
± ± ±
±
±
3
0.018
0.018
±
± ±
± ± ± ±
± ±
0.018
±
±
±
± ± ±
±
±
In H-1, H-2, H-3 gas was sampled between start ± 20, 20±40, 40 min ± end of a cremation, respectively.
Total (PCDDs+PCDFs)
PCDFs
PCDDs
PCDDs/PCDFs isomer and homologue (ng TEQ/ N m3 )
Table 4 (Continued)
4
0.064
0.064
±
± ±
± ± ± ±
± 0.048
0.016
±
±
±
± ± ±
±
±
0.045
0.045
±
± ±
± ± ± ±
± ±
0.045
±
±
±
± ± ±
±
±
1
I 2
0.68
0.56
±
0.0095 ±
± ± ± ±
0.033 0.45
0.060
0.13
±
±
± ± ±
±
0.13
0.42
0.34
±
0.0033 ±
0.038 ± ± ±
0.015 0.17
0.11
0.084
±
±
± ± ±
±
0.084
1
J 2
0.99
0.75
0.00028
0.0062 0.0014
0.029 0.033 ± 0.031
0.030 0.44
0.17
0.24
0.00015
0.0017
0.0050 0.0064 0.015
0.055
0.16
582 N. Takeda et al. / Chemosphere 40 (2000) 575±586
N. Takeda et al. / Chemosphere 40 (2000) 575±586
583
Fig. 3. Homologue pattern of PCDDs/DFs of crematory C.
Fig. 1. Total concentration of PCDDs/DFs vs. total toxic equivalent concentration.
Fig. 4. Homologue pattern of PCDDs/DFs of crematory A.
Fig. 2. Isomer pattern of PCDDs/DFs of crematory C.
crematory C became extremely high three times. CO concentration in crematory H had a rapid change in the ®rst 20 min when total concentration of PCDDs/DFs was the highest. Moreover, CO concentration rose slightly for a short time period when a rake was used to move the dead body in the furnace. It is recognized that CO concentration correlates with PCDDs/DFs concentrations. O2 12% normalized NOx concentration was 100±150 ppm, and HCl concentration was no more than 120 mg/ N m3 . The relation between concentrations of these gases and the total concentration of PCDDs/DFs cannot be identi®ed.
Fig. 5. Total concentration of PCDDs/DFs vs. dust concentration.
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N. Takeda et al. / Chemosphere 40 (2000) 575±586
4.3. PCDDs/DFs and structural factors of crematory 4.3.1. Construction/improvement year of crematory The total concentration of PCDDs/DFs for the crematories that were constructed in 1990s was lower than that for the crematories constructed before 1990. The total concentration was high in the crematories whose secondary combustion chambers are connected to more than two main combustion chambers.
Fig. 6. Total concentration of PCDDs/DFs vs. temperature in secondary combustion chamber.
4.3.2. Secondary combustion chamber There are 1607 crematories in Japan, and 25% of the crematories have no secondary combustion chamber. All crematories that we investigated involve secondary combustion chambers, but crematory C, which had the highest PCDDs/DFs concentrations, did not use the secondary combustion chamber ordinarily or in the sampling period.
Fig. 7. A chart of O2 , CO, NOx concentration in crematory C.
Fig. 8. A chart of O2 , CO, NOx concentrations in crematory H.
N. Takeda et al. / Chemosphere 40 (2000) 575±586
585
Table 5 Relation between PCDDs/DFs concentration and structural factors of crematoriesa Order
1
2
3
4
5
6
7
8
9
10
Crematory The number of sampling execution Total PCDDs/DFs (ng TEQ/N m3 ) Existence of secondary chamber Ratio of the numbers of main and secondary chambers Existence of dust collector
C 2
A 2
G 3
J 2
B 2
I 2
H 1
E 2
F 3
D 2
5.25
2.70
0.90
0.71
0.50
0.36
0.064
0.048
0.038
0.026
s(´)
s
s
s
s
s
s
s
s
s
4:1
3:1
1:1
3:1
1:1
1:1
1:1
1:1
1:1
1:1
´
s
´
´
s
´
´
s
s
s
a 1. s(´) means that crematory C involves a secondary chamber but does not use. 2. Total PCDDs/DFs shows an average of the sampling results.
Crematories are sorted in order of averaged TEQ concentration of PCDDs/DFs in Table 5, and each ratio of the numbers of main and secondary combustion chambers is shown in the table. It is clear that the higher the number of main combustion chambers which share one secondary combustion chamber the higher the PCDDs/DFs concentration. 4.3.3. Dust collector Seventy percent of the crematories in Japan use no dust collector. The concentration of PCDDs/DFs in crematories that use dust collectors tends to be low. However, the concentration of PCDDs/DFs in crematory A is high in spite of using a dust collector. The dust collectors used in crematory vary widely from a collector which can remove only coarse dust (e.g., metal nets and metal plates with holes) to a collector which can remove ®ne dust (e.g., cyclone, electrostatic precipitator and bag ®lters). Therefore, eciency of dust reduction depends on the dust collector.
5. Total emission from all crematories in Japan Total emission from all crematories in Japan was estimated. The total emission is de®ned as the following equations:
Total emission ng TEQ=yr emission quantity the number of crematories bodies=yr; Emission quantity ng TEQ=body an average of TEQ concentration ng TEQ=N m3 dry gas volume N m3 =h cremation period h=body The result is shown in column (A) of Table 6. The emission quantity was 42±62 000 ng TEQ/body and the average resulted in 9200 ng TEQ/body. To avoid underestimation, additional emission quantity was calculated regarding N.D. as a half value of the detection limit. The result is shown in column (B) of Table 6. The lower estimation was about 10 times greater than that in column (A), and the average became 11 000 (ng TEQ/ body). Total emission was calculated by multiplying the average by the number of cremations in Japan, 963 318 (bodies/yr), and resulted in (A) 8.9 g TEQ/yr and (B) 11 g TEQ/yr. The expected error caused by neglecting concentrations which were lower than the detection limit was about 24%. The total amount of emission was equal to one ®ve hundredth of that from refuse incinerators and was greater than that from sewage sludge
Table 6 Estimated total emission PCDDs/DFs from all crematories in Japana Emission per body
Total emission a
Lower level Upper level Average
Unit
(A)
(B)
(B)/(A)
ng TEQ/body ng TEQ/body ng TEQ/body
42 62 000 9 200
450 63 000 11 000
10.7 1.02 1.20
11
1.24
ng TEQ/body
8.9
(A) The case of regarding N.D. as 0.0. (B) The case of regarding N.D. as half value of the detection limit.
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N. Takeda et al. / Chemosphere 40 (2000) 575±586
incinerators. Since there are many crematories without secondary combustion chambers, the crematories are considered as one of the largest emission sources. 6. Conclusion In this research, concentrations of PCDDs and PCDFs in emission gases from 10 crematories were measured. The relationship between dioxins and several factors such as structure, equipment and operational state of the crematory is discussed. Furthermore, total emission of PCDDs/DFs from crematories in Japan is estimated. Results are summarized as below: 1. Total concentration of PCDDs/DFs from a crematory was 2.2±290 ng/N m3 , and TEQ concentration was 0.0099±6.5 ng TEQ/N m3 . 2. Concentration of PCDFs was higher than that of PCDDs, especially T4CDFs were the highest and 2,3,7,8-T4CDF was detected in almost all samples. 3. For a homologue pattern of PCDFs, the concentration of T4CDFs was high and that of the higher chlorinated compounds was low. For that of PCDDs, two patterns were identi®ed: (i) a mountain shape pattern with peaks of H6CDDs, which is similar to the typical pattern of waste incinerators, and (ii) a pattern the same as the PCDFs pattern. 4. The total concentration of PCDDs/DFs from crematories whose dust concentration is less than 50 mg/N m3 tends to be low. 5. Total concentration of PCDDs/DFs was highest in the ®rst 20 min from the start. Although concentrations for middle 20 min and last 20 min followed,
dierences between the three values were not so large. 6. It was found that sex and age of dead body does not aect the concentration of PCDDs/DFs. 7. Existence of a dust collector, temperature of the secondary combustion chamber and the number of main combustion chambers connected to a secondary combustion chamber aected the concentration of PCDDs/DFs. 8. The total amount of PCDDs/DFs emitted from crematories in Japan was estimated to be 8.9 g TEQ/yr.
Acknowledgements This research was supported by Health Sciences Research Grants in FY1997 of Japanese Government. References Hiraoka, M., Okajima, S., 1994. Source control technologies in MSW incinerator plants. Organohalogen Compounds 19, 275±291. Eguchi, S., Takeda, N., Sakai, S., 1996. PCDDs/PCDFs emission from a crematory. Organohalogen Compounds 27, 127±132. Hutzinger, O., Fiedler, H., From source to exposure: some open questions. Chemosphere 27 (1±3), 121±129. The Working Group of Subcommittee, 1993. Air/technology of the Federal Government Federal State Pollution Control Committee, Germany: determination of requirements to limit emissions of dioxins and furans, pp. 127±129. Shimazaki, A., 1997. Kaso Gairon, third ed. Japan Society of Environmental Crematory, 165 pp.
PCDDs/DFs emissions from crematories in Japan Nobuo Takedaa,*, Masaki Takaokaa, Takeshi Fujiwaraa, Hisayuki Takeyamab, Shoji Eguchib a
Environmental Engineering, Graduate School of Engineering, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan b Japan Society of Environmental Crematory, 6-3 Miyamoto, Kawasaki-ku, Kawasaki 210-0004, Japan Received 10 March 1999; accepted 21 May 1999
Abstract Concentrations of PCDDs and PCDFs in emission gases from 10 crematories were measured. The relationship between PCDDs/DFs and several factors such as structure, equipment and operational state of the crematory is discussed. Furthermore, emission of PCDDs/DFs from all crematories in Japan is estimated. The following results are obtained: (1) total concentration of PCDDs/DFs was 2.2±290 ng/N m3 , whose TEQ concentration was 0.0099±6.5 ng TEQ/N m3 ; (2) total concentration of PCDFs was higher than that of PCDDs; (3) T4CDFs was the highest in the homologue pattern and 2,3,7,8-T4CDF was the highest in the isomer pattern; (4) emission of PCDDs/DFs was the largest in the ®rst 20 min of cremation; (5) concentration of PCDDs/DFs was related to the existence of a secondary combustion chamber and a dust collector, and the ratio of the numbers of main and secondary combustion chambers; (6) total emission of PCDDs/DFs from crematories in Japan was estimated to be 8.9 g TEQ/yr. Ó 2000 Elsevier Science Ltd. All rights reserved. Keywords: PCDDs/DFs; Crematory; Combustion; Emission gas; Gas sampling
1. Introduction Recently, dioxin emissions from refuse incinerators have become a serious problem in Japan. Although there are studies to estimate the quantity of dioxins emitted from industrial waste incinerators, steel manufacturing and automobiles (Hiraoka and Okajima, 1994), only a few studies have been carried out on dioxin emissions from crematories. Eguchi et al. (1996) reported the concentration of dioxins from a crematory in Japan to be 0.14±2.56 ng TEQ/N m3 . This is less than the concentration of dioxins from crematories in Germany at 8 ng TEQ/N m3 as reported by Hutzinger and Fiedler (1993). A working group of a sub-
*
Corresponding author.
committee of the German federal state pollution control committee investigated concentration of dioxins in 1994 for 13 crematories which are selected from 100 crematories in Germany, and reported that the concentration of dioxins from crematories was 0.1±14.4 ng TEQ/N m3 and almost all of them were more than 1 ng TEQ/N m3 (The Working Group of Subcommittee, 1993). Since more than 99% of dead bodies are cremated in 1607 crematories in Japan, it is necessary to investigate many crematories of various types to estimate the quantity of dioxins emitted from crematories. In this research, concentrations of PCDDs and PCDFs in emission gases from 10 crematories were measured. The relationship between dioxins and several factors such as structure, equipment and operational state of the crematory is discussed. Furthermore, total emission of PCDDs/DFs from crematories in Japan is estimated.
0045-6535/00/$ - see front matter Ó 2000 Elsevier Science Ltd. All rights reserved. PII: S 0 0 4 5 - 6 5 3 5 ( 9 9 ) 0 0 2 3 2 - 5
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N. Takeda et al. / Chemosphere 40 (2000) 575±586
2. Custom of funeral in Japan Funeral rite usually depends on religion and custom of a country. In Japan, 99% (in 1995) of dead bodies are cremated and the percentage is the highest in the world (Shimazaki, 1997). Since the bone ash of a dead person is collected by his/her bereaved family at the end of cremation in Japan, the dead bodies must be burned and cooled down in a furnace, one by one. So that, a crematory site involves multiple furnaces (48 furnaces in a crematory is the largest in Japan) and the furnace is operated not continuously but batch-wise. Capacity of each furnace is small and treatment equipment of the emission gas is simple. Especially, old-fashioned crematories remaining widely in Japan involve no equipment for gas treatment. For this reason, concentration of dioxins from crematories should be investigated. The typical cremation procedure performed in Japan is as follows: 1. A secondary burner is ignited to warm up a secondary combustion chamber. 2. A con containing a dead body is placed into a main combustion chamber. 3. A main burner is ignited to burn the con and dead body. 4. The secondary burner is turned o because calories from the dead body and the fuel for the main burner are enough to keep temperature of the secondary combustion chamber high. 5. The main burner is turned o after everything with exception of bones are burned. 6. The main combustion chamber is cooled down by blowing air into it. 7. The bereaved family collect the bone ash. By considering this procedure, it is decided that igniting the secondary burner and turning o the main burner are regarded as start and end of gas sampling. 3. Measurement method of PCDDs/DFs concentration in emission gas Table 1 shows the 10 crematories studied in this work. The number of cremations in these crematories occupied 4% of the number of total cremations in Japan. The construction or improvement year of the crematory is from 1985 onward. In crematories A, C and J, a secondary combustion chamber is connected to three or four main combustion chambers so that the ¯ue gases from more than two main combustion chambers go into the secondary combustion chamber simultaneously. In order to take account of overlapped cremation in multiple furnaces during measurement, the eective number of cremations was calculated by dividing the sum of the cremation
period in all of main combustion chambers by the average cremation period for a dead body. Flue gas was sampled throughout a cremation, i.e., from igniting the secondary burner to turning o the main burner (only gas sampling for HCl was terminated at 20 min after ignition of the secondary burner). During the sampling period, concentrations of dust, O2 , CO, HCl and NOx were measured, and temperatures of the main/secondary combustion chambers and ¯ue gas were observed. Moreover, age and sex of the dead bodies, and accompanied equipment in cons were recorded. Concentrations of PCDDs/DFs were measured according to the manual of the Ministry of Health and Welfare of Japan and the USEPA method 23. GC/MS (Auto Spec ULTIMA by Micro Mass) with a column DB-5 was used to measure concentrations of PCDDs/ DFs, and a column DB-225 was used when the separation eciency of 2,3,7,8-T4CDF when using the column DB-5 was insucient. Equations to calculate PCDDs/ DFs concentration are listed in Table 2. 4. Results and discussion 4.1. Results of PCDDs/DFs Measured concentrations of PCDDs/DFs (12% O2 normalized) and the toxic equivalent concentrations are shown in Tables 3 and 4, respectively. Total concentration of PCDDs/DFs was 2.2±290 ng/N m3 , whose TEQ concentration was 0.0099±6.5 ng TEQ/N m3 . The total concentration of PCDFs was higher than that of PCDDs in all samples except of crematory A. 4.1.1. The total and the TEQ concentration of PCDDs/ DFs The relationship between the total and the TEQ concentrations of PCDDs/DFs is shown in Fig. 1, and the regression line for the refuse incinerator is also shown using a dotted line for comparison. The ratio of the two concentrations for crematories was about 2.1%, and it was larger than that for refuse incinerators, 1.6%. The reason for this is that a greater amount of T4CDFs which have a large TEF are included in PCDFs. 4.1.2. Homologue and isomer patterns Homologue patterns of crematory C and A are shown in Figs. 3 and 4, respectively, and an isomer pattern of crematory C is shown in Fig. 2. The concentration of T4CDFs was highest in the homologue pattern of PCDFs and the concentration lowered as the number of bonded chlorine atoms increased. Although the magnitude of PCDDs was not uniform, two homologue patterns of PCDDs were identi®ed: one has high concentration of T4CDDs (Fig. 3) and the other has a mountain shape (Fig. 4). The former pattern is
a
Sampling period (min)
Gas sampling 3
67 M 75 1
83
M 72 1
F 92 1.5
64
F 70 2.4
s s 83 F 72
M 52 1
94
F 93 1
s ´ 77
Town gas ´
s s Induced 1
s(´)a ´ Induced 4 Kerosene s
D
C
s(´) means the crematory C has a secondary chamber but does not use it.
Dead body Sex Age The number of cremations
Sampling period (min) Dead body Sex Age The number of cremations
M 85 1
F 93 3
Gas sampling 2
s s 47
s s 82 M 68
Town gas s
Kerosene s
M 70
s s Induced 1
s s Induced 3
B
A
Code of crematory
Secondary chamber Dust collector Ventilation The number of main chambers connected to a secondary chamber Burner fuel TemperaMain ture Secondary Flue gas Gas Sampling period sampling 1 (min) Dead body Sex Age The number of cremations
Table 1 Con®guration of crematory and sampling condition
F 72 1
57
F 86 1
s ´ 64
Kerosene s
s s Induced 1
E
M 74 1
64
M 82 1
66
M 62 1
s s 63
Kerosene s
s s Induced 1
F
F 89 1.3
58
M 57 1.2
68
M 56 1.1
s s 67
Kerosene ´
s ´ Induced 1
G
M 23 1
114
M 85 1
s ´ 75
A heavy oil ´
s ´ Induced 1
H
F 61 1
78
M 61 1
s ´ 90
Kerosene ´
s ´ Induced 1
I
F 74 2.4
92
F 101 3
´ ´ 117
F 89
M 72
A heavy oil ´
s ´ Induced 3
J
N. Takeda et al. / Chemosphere 40 (2000) 575±586 577
578
N. Takeda et al. / Chemosphere 40 (2000) 575±586
Table 2 De®nition of concentration calculationa Measured concentration Cs
analized quantity intake of emission gas
Limit of quantification LOQ
detection limit DL intake of emission gas
O2 12% normalized concentration C
21 ÿ 12 Cs 21 ÿ O2 concentration Os
Toxic equivalent concentration C ´ international toxic equivalent factor (TEF) a
If whole concentrations of the isomers are lower than LOQ, then concentration taking account of Ôlower than LOQÕ LOQ 12 TEF.
considered to be characteristic of crematory. From patterns of 17 kinds of toxic isomers that include chlorine atoms at least at 2, 3, 7 and 8 positions, it was found that the concentration of 2,3,7,8-T4CDF is the largest. The same homologous and isomer patterns are found in almost all crematories, and this suggests that the patterns are typical for cremations and or do not depend on the condition of the dead body, age, sex, funeral materials, and so on. 4.1.3. Time trend of concentration To identify the time trend of PCDDs/DFs concentrations, the ¯ue gas was sampled during 0±20, 20±40, and 40 min ± the end, respectively, in crematory H. It was assumed that the con and other funeral materials caught ®re in the ®rst period, and easily combustible parts and other parts of the dead body started to burn in the second and the last periods, respectively. The TEQ concentration was the greatest in the ®rst period (0.027), which was followed by the second (0.023), and the third (0.018). Although the dierences among these concentrations were small, it can be said that the total TEQ concentration in the ®rst 20 min is higher than that in the second 20 min. This is similar to the result shown by Eguchi et al. (1996). It is considered that burning of the con and other funeral materials caused high concentrations of PCDDs/DFs. 4.1.4. Age and sex of a dead body Dierences in the concentration by age and sex of the dead body could not be identi®ed, but the number of samples was not enough to draw any conclusion. 4.2. PCDDs/DFs and components in emission gas 4.2.1. Dust concentration High concentration of dust was detected in the crematories having no dust collector. Black smoke emitted from a stack and an excessively high concentration of CO was observed in such crematories. The relation be-
tween dust concentration and total concentration of PCDDs/DFs is shown in Fig. 5. One crematory has over 700 mg/N m3 , but total concentration of PCDDs/DFs was not very high (27 ng/N m3 ). The concentration was low in the crematories whose dust concentration was less than 50 mg/N m3 . Thus, it is considered that emission of PCDDs/DFs is reduced by dust collectors. 4.2.2. Temperature of secondary combustion chamber In every crematory, the temperature in the main combustion chambers increased rapidly up to 800°C in the ®rst 10 min after start up. The relationship between the temperature in the secondary combustion chamber at a steady state and total concentration of PCDDs/DFs is shown in Fig. 6. The concentration was low in the crematory whose temperature was above 850°C. 4.2.3. O2 , CO, NOx and HCl concentrations Charts of O2 , CO and NOx concentrations during the sampling period of crematories C and H are shown in Figs. 7 and 8, respectively. Because air is blown into a duct which is connected to an exit of the secondary combustion chamber to dilute and cool down combustion gas, O2 concentration was higher (about 15±20%) than that in the refuse incinerator. O2 concentration depends on the crematory: O2 concentration in crematory C was constantly high but the concentration changed with time in crematory H. Since addition of large amount of air makes concentrations of PCDDs/DFs lower than the detection limit, total amount of PCDDs/DFs that is calculated by multiplying gas volume and the concentration is estimated lower than the actual amount. Therefore, an appropriate method to measure the concentrations for the crematory should be considered. In some crematories, it was found that concentration of CO increases and decreases quickly soon after ignition of main/secondary burners and extinction of the secondary burner. Especially, CO concentration in
Total (PCDDs+PCDFs)
PCDFs
PCDDs
PCDDs/PCDFs isomer and homologue (ng/N m3 )
96
Total PCDFs 190
1.3 32 1.4 2.8 26 2.5 2.0 0.17 2.4 20 7.9 1.4 14 4.1
2,3,7,8-T4CDF T4CDFs 1,2,3,7,8-P5CDF 2,3,4,7,8-P5CDF P5CDFs 1,2,3,4,7,8-H6CDF 1,2,3,6,7,8-H6CDF 1,2,3,7,8,9-H6CDF 2,3,4,6,7,8-H6CDF H6CDFs 1,2,3,4,6,7,8-H7CDF 1,2,3,4,7,8,9-H7CDF H7CDFs O8CDF
98
Total PCDDs
82
49
0.82 21 0.91 1.2 14 0.85 0.88 ± 0.85 7.7 2.5 0.54 4.8 1.7
34
0.16 4.3 0.40 6.8 0.37 0.88 0.74 11 4.0 7.7 4.3
2
6.5
5.5
0.30 5.5 ± ± ± ± ± ± ± ± ± ± ± ±
0.96
± 0.96 ± ± ± ± ± ± ± ± ±
1
0.20 8.4 0.97 20 1.0 2.6 2.1 29 13 25 16
1
2,3,7,8-T4CDD T4CDDs 1,2,3,7,8-P5CDD P5CDDs 1,2,3,4,7,8-H6CDD 1,2,3,6,7,8-H6CDD 1,2,3,7,8,9-H6CDD H6CDDs 1,2,3,4,6,7,8-H7CDD H7CDDs O8CDD
B
A
Crematory
Table 3 Concentrations of PCDDs/DFs in emission gas of crematories
42
34
1.1 20 ± 1.6 9.2 ± ± ± ± 2.2 1.8 ± 1.8 ±
8.0
± 2.2 ± ± ± ± ± 2.8 1.7 3.0 ±
2
290
220
7.4 140 4.3 5.4 64 2.7 2.7 ± 2.1 17 2.9 ± 2.9 ±
70
1.1 31 1.4 19 ± ± 1.7 15 2.4 4.7 ±
1
C
230
180
6.5 120 3.3 4.0 45 ± 2.1 ± ± 7.4 2.7 ± 2.7 ±
53
0.94 28 ± 10 ± ± ± 12 ± 2.2 ±
2
3.5
3.5
0.28 2.8 ± ± 0.62 ± ± ± ± ± ± ± ± ±
±
± ± ± ± ± ± ± ± ± ± ±
1
D
7.3
6.9
0.24 6.0 ± ± 0.90 ± ± ± ± ± ± ± ± ±
0.41
± 0.41 ± ± ± ± ± ± ± ± ±
2
20
19
0.49 15 ± ± 4.0 ± ± ± ± ± ± ± ± ±
0.89
± 0.89 ± ± ± ± ± ± ± ± ±
1
E
18
18
0.47 13 ± ± 4.3 ± ± ± ± ± ± ± ± ±
0.31
± 0.31 ± ± ± ± ± ± ± ± ±
2
2.8
2.5
0.13 2.0 ± ± 0.42 ± ± ± ± ± ± ± ± ±
0.33
± 0.33 ± ± ± ± ± ± ± ± ±
1
F
3.1
2.7
0.089 1.4 ± 0.16 0.76 ± ± ± ± 0.27 0.25 ± 0.25 ±
0.47
± 0.20 ± 0.12 ± ± ± 0.15 ± ± ±
2
2.2
2.1
0.099 1.7 ± ± 0.37 ± ± ± ± ± ± ± ± ±
0.091
± 0.091 ± ± ± ± ± ± ± ± ±
3
N. Takeda et al. / Chemosphere 40 (2000) 575±586 579
a
14
Total PCDFs 19
0.41 6.8 0.31 0.48 4.2 0.47 0.30 ± ± 1.9 0.88 ± 0.88 ±
2,3,7,8-T4CDF T4CDFs 1,2,3,7,8-P5CDF 2,3,4,7,8-P5CDF P5CDFs 1,2,3,4,7,8-H6CDF 1,2,3,6,7,8-H6CDF 1,2,3,7,8,9-H6CDF 2,3,4,6,7,8-H6CDF H6CDFs 1,2,3,4,6,7,8-H7CDF 1,2,3,4,7,8,9-H7CDF H7CDFs O8CDF
5.4
Total PCDDs
31
22
0.53 11 0.40 0.88 6.6 0.48 0.41 ± 0.35 2.5 0.88 ± 1.4 ±
8.6
± 1.8 0.23 2.2 ± ± 0.40 2.2 0.75 1.6 0.75
2
3
66
42
0.69 19 0.69 1.7 14 1.1 0.87 ± 1.1 4.7 2.1 0.49 4.1 0.75
24
± 5.4 ± 7.5 0.47 0.62 1.00 6.9 1.9 3.4 1.2
15
9.2
0.27 8.1 ± ± 1.1 ± ± ± ± ± ± ± ± ±
6.1
± 6.1 ± ± ± ± ± ± ± ± ±
1
± 1.1 ± 1.1 ± ± ± 1.2 0.62 1.2 0.73
1
2,3,7,8-T4CDD T4CDDs 1,2,3,7,8-P5CDD P5CDDs 1,2,3,4,7,8-H6CDD 1,2,3,6,7,8-H6CDD 1,2,3,7,8,9-H6CDD H6CDDs 1,2,3,4,6,7,8-H7CDD H7CDDs O8CDD
Ha
G
Crematory
4.7
4.4
0.23 3.9 ± ± 0.51 ± ± ± ± ± ± ± ± ±
0.28
± 0.28 ± ± ± ± ± ± ± ± ±
2
4.6
4.5
0.18 4.0 ± ± 0.55 ± ± ± ± ± ± ± ± ±
0.092
± 0.092 ± ± ± ± ± ± ± ± ±
3
In H-1, H-2, H-3 gas was sampled between start ± 20, 20±40, 40 min ± end of a cremation, respectively.
Total (PCDDs+PCDFs)
PCDFs
PCDDs
PCDDs/PCDFs isomer and homologue (ng/N m3 )
Table 3 (Continued)
4.2
3.7
0.16 3.2 ± 0.097 0.56 ± ± ± ± ± ± ± ± ±
0.48
± 0.48 ± ± ± ± ± ± ± ± ±
4
8.2
7.8
0.45 5.7 ± ± 1.4 ± ± ± ± 0.76 ± ± ± ±
0.37
± 0.37 ± ± ± ± ± ± ± ± ±
1
I
22
21
0.60 10 0.67 0.91 6.9 ± ± ± ± 2.3 0.95 ± 0.95 ±
1.5
0.13 0.72 ± ± ± ± ± 0.79 ± ± ±
2
27
26
1.1 20 0.30 0.35 4.1 0.38 ± ± ± 0.75 0.33 ± 0.33 ±
0.99
0.084 0.99 ± ± ± ± ± ± ± ± ±
1
J
47
41
1.7 30 0.60 0.88 6.8 0.29 0.33 ± 0.31 2.8 0.62 0.14 1.1 0.28
5.3
0.16 3.2 0.11 0.92 0.050 0.064 0.15 0.73 0.17 0.30 0.15
2
580 N. Takeda et al. / Chemosphere 40 (2000) 575±586
Total (PCDDs+PCDFs)
PCDFs
PCDDs
PCDDs/PCDFs isomer and homologue (ng TEQ/N m3 )
0.20 0.037 0.088 0.074 0.040 0.0043
0.49 0.10 0.26 0.21 0.13 0.016 1.4
Total PCDDs
0.085 0.088 ± 0.085 0.025 0.0054 0.0017
0.25 0.20 0.017 0.24 0.079 0.014 0.0041 2.4
Total PCDFs 3.8
0.046 0.61
0.072 1.4
1.6
1.0
0.082
0.13
2,3,7,8-T4CDF T4CDFs 1,2,3,7,8-P5CDF 2,3,4,7,8-P5CDF P5CDFs 1,2,3,4,7,8-H6CDF 1,2,3,6,7,8-H6CDF 1,2,3,7,8,9-H6CDF 2,3,4,6,7,8-H6CDF H6CDFs 1,2,3,4,6,7,8-H7CDF 1,2,3,4,7,8,9-H7CDF H7CDFs O8CDF
0.60
0.16
0.2
2,3,7,8-T4CDD T4CDDs 1,2,3,7,8-P5CDD P5CDDs 1,2,3,4,7,8-H6CDD 1,2,3,6,7,8-H6CDD 1,2,3,7,8,9-H6CDD H6CDDs 1,2,3,4,6,7,8-H7CDD H7CDDs O8CDD
0.030
0.030
±
± ±
± ± ± ±
± ±
0.030
±
±
±
± ± ±
±
±
1
1
2
B
A
Crematory
0.96
0.94
±
0.018 ±
± ± ± ±
± 0.82
0.11
0.017
±
0.017
± ± ±
±
±
2
Toxic equivalent concentrations (TEQ) of PCDDs/DFs in emission gas of crematories
Table 4
6.5
4.5
±
0.029 ±
0.27 0.27 ± 0.21
0.21 2.7
0.74
2.0
±
0.024
± ± 0.17
0.72
1.1
1
C
4.0
3.1
±
0.027 ±
± 0.21 ± ±
0.17 2.0
0.65
0.94
±
±
± ± ±
±
0.94
2
0.028
0.028
±
± ±
± ± ± ±
± ±
0.028
±
±
±
± ± ±
±
±
1
D
0.024
0.024
±
± ±
± ± ± ±
± ±
0.024
±
±
±
± ± ±
±
±
2
0.049
0.049
±
± ±
± ± ± ±
± ±
0.049
±
±
±
± ± ±
±
±
1
E
0.047
0.047
±
± ±
± ± ± ±
± ±
0.047
±
±
±
± ± ±
±
±
2
0.013
0.013
±
± ±
± ± ± ±
± ±
0.013
±
±
±
± ± ±
±
±
1
F
0.091
0.091
±
0.0025 ±
± ± ± ±
± 0.080
0.0089
±
±
±
± ± ±
±
±
2
0.0099
0.0099
±
± ±
± ± ± ±
± ±
0.0099
±
±
±
± ± ±
±
±
3
N. Takeda et al. / Chemosphere 40 (2000) 575±586 581
a
3
± ± 0.040 0.0075 0.00075
± ± ± 0.0062 0.00073 0.0070
Total PCDDs
0.048 0.041 ± 0.035 0.0088 ± ±
0.047 0.030 ± ± 0.0088 ± ± 0.38
Total PCDFs 0.39
0.020 0.44
0.016 0.24
0.81
0.65
0.053
0.041
2,3,7,8-T4CDF T4CDFs 1,2,3,7,8-P5CDF 2,3,4,7,8-P5CDF P5CDFs 1,2,3,4,7,8-H6CDF 1,2,3,6,7,8-H6CDF 1,2,3,7,8,9-H6CDF 2,3,4,6,7,8-H6CDF H6CDFs 1,2,3,4,6,7,8-H7CDF 1,2,3,4,7,8,9-H7CDF H7CDFs O8CDF
0.17
0.12
±
1.5
1.3
0.00075
0.021 0.0049
0.11 0.087 ± 0.11
0.034 0.84
0.069
0.23
0.0012
0.019
0.047 0.062 0.100
±
±
0.027
0.027
±
± ±
± ± ± ±
± ±
0.027
±
±
±
± ± ±
±
±
1
2 ±
1 ±
2,3,7,8-T4CDD T4CDDs 1,2,3,7,8-P5CDD P5CDDs 1,2,3,4,7,8-H6CDD 1,2,3,6,7,8-H6CDD 1,2,3,7,8,9-H6CDD H6CDDs 1,2,3,4,6,7,8-H7CDD H7CDDs O8CDD
Ha
Crematory
G 2
0.023
0.023
±
± ±
± ± ± ±
± ±
0.023
±
±
±
± ± ±
±
±
3
0.018
0.018
±
± ±
± ± ± ±
± ±
0.018
±
±
±
± ± ±
±
±
In H-1, H-2, H-3 gas was sampled between start ± 20, 20±40, 40 min ± end of a cremation, respectively.
Total (PCDDs+PCDFs)
PCDFs
PCDDs
PCDDs/PCDFs isomer and homologue (ng TEQ/ N m3 )
Table 4 (Continued)
4
0.064
0.064
±
± ±
± ± ± ±
± 0.048
0.016
±
±
±
± ± ±
±
±
0.045
0.045
±
± ±
± ± ± ±
± ±
0.045
±
±
±
± ± ±
±
±
1
I 2
0.68
0.56
±
0.0095 ±
± ± ± ±
0.033 0.45
0.060
0.13
±
±
± ± ±
±
0.13
0.42
0.34
±
0.0033 ±
0.038 ± ± ±
0.015 0.17
0.11
0.084
±
±
± ± ±
±
0.084
1
J 2
0.99
0.75
0.00028
0.0062 0.0014
0.029 0.033 ± 0.031
0.030 0.44
0.17
0.24
0.00015
0.0017
0.0050 0.0064 0.015
0.055
0.16
582 N. Takeda et al. / Chemosphere 40 (2000) 575±586
N. Takeda et al. / Chemosphere 40 (2000) 575±586
583
Fig. 3. Homologue pattern of PCDDs/DFs of crematory C.
Fig. 1. Total concentration of PCDDs/DFs vs. total toxic equivalent concentration.
Fig. 4. Homologue pattern of PCDDs/DFs of crematory A.
Fig. 2. Isomer pattern of PCDDs/DFs of crematory C.
crematory C became extremely high three times. CO concentration in crematory H had a rapid change in the ®rst 20 min when total concentration of PCDDs/DFs was the highest. Moreover, CO concentration rose slightly for a short time period when a rake was used to move the dead body in the furnace. It is recognized that CO concentration correlates with PCDDs/DFs concentrations. O2 12% normalized NOx concentration was 100±150 ppm, and HCl concentration was no more than 120 mg/ N m3 . The relation between concentrations of these gases and the total concentration of PCDDs/DFs cannot be identi®ed.
Fig. 5. Total concentration of PCDDs/DFs vs. dust concentration.
584
N. Takeda et al. / Chemosphere 40 (2000) 575±586
4.3. PCDDs/DFs and structural factors of crematory 4.3.1. Construction/improvement year of crematory The total concentration of PCDDs/DFs for the crematories that were constructed in 1990s was lower than that for the crematories constructed before 1990. The total concentration was high in the crematories whose secondary combustion chambers are connected to more than two main combustion chambers.
Fig. 6. Total concentration of PCDDs/DFs vs. temperature in secondary combustion chamber.
4.3.2. Secondary combustion chamber There are 1607 crematories in Japan, and 25% of the crematories have no secondary combustion chamber. All crematories that we investigated involve secondary combustion chambers, but crematory C, which had the highest PCDDs/DFs concentrations, did not use the secondary combustion chamber ordinarily or in the sampling period.
Fig. 7. A chart of O2 , CO, NOx concentration in crematory C.
Fig. 8. A chart of O2 , CO, NOx concentrations in crematory H.
N. Takeda et al. / Chemosphere 40 (2000) 575±586
585
Table 5 Relation between PCDDs/DFs concentration and structural factors of crematoriesa Order
1
2
3
4
5
6
7
8
9
10
Crematory The number of sampling execution Total PCDDs/DFs (ng TEQ/N m3 ) Existence of secondary chamber Ratio of the numbers of main and secondary chambers Existence of dust collector
C 2
A 2
G 3
J 2
B 2
I 2
H 1
E 2
F 3
D 2
5.25
2.70
0.90
0.71
0.50
0.36
0.064
0.048
0.038
0.026
s(´)
s
s
s
s
s
s
s
s
s
4:1
3:1
1:1
3:1
1:1
1:1
1:1
1:1
1:1
1:1
´
s
´
´
s
´
´
s
s
s
a 1. s(´) means that crematory C involves a secondary chamber but does not use. 2. Total PCDDs/DFs shows an average of the sampling results.
Crematories are sorted in order of averaged TEQ concentration of PCDDs/DFs in Table 5, and each ratio of the numbers of main and secondary combustion chambers is shown in the table. It is clear that the higher the number of main combustion chambers which share one secondary combustion chamber the higher the PCDDs/DFs concentration. 4.3.3. Dust collector Seventy percent of the crematories in Japan use no dust collector. The concentration of PCDDs/DFs in crematories that use dust collectors tends to be low. However, the concentration of PCDDs/DFs in crematory A is high in spite of using a dust collector. The dust collectors used in crematory vary widely from a collector which can remove only coarse dust (e.g., metal nets and metal plates with holes) to a collector which can remove ®ne dust (e.g., cyclone, electrostatic precipitator and bag ®lters). Therefore, eciency of dust reduction depends on the dust collector.
5. Total emission from all crematories in Japan Total emission from all crematories in Japan was estimated. The total emission is de®ned as the following equations:
Total emission ng TEQ=yr emission quantity the number of crematories bodies=yr; Emission quantity ng TEQ=body an average of TEQ concentration ng TEQ=N m3 dry gas volume N m3 =h cremation period h=body The result is shown in column (A) of Table 6. The emission quantity was 42±62 000 ng TEQ/body and the average resulted in 9200 ng TEQ/body. To avoid underestimation, additional emission quantity was calculated regarding N.D. as a half value of the detection limit. The result is shown in column (B) of Table 6. The lower estimation was about 10 times greater than that in column (A), and the average became 11 000 (ng TEQ/ body). Total emission was calculated by multiplying the average by the number of cremations in Japan, 963 318 (bodies/yr), and resulted in (A) 8.9 g TEQ/yr and (B) 11 g TEQ/yr. The expected error caused by neglecting concentrations which were lower than the detection limit was about 24%. The total amount of emission was equal to one ®ve hundredth of that from refuse incinerators and was greater than that from sewage sludge
Table 6 Estimated total emission PCDDs/DFs from all crematories in Japana Emission per body
Total emission a
Lower level Upper level Average
Unit
(A)
(B)
(B)/(A)
ng TEQ/body ng TEQ/body ng TEQ/body
42 62 000 9 200
450 63 000 11 000
10.7 1.02 1.20
11
1.24
ng TEQ/body
8.9
(A) The case of regarding N.D. as 0.0. (B) The case of regarding N.D. as half value of the detection limit.
586
N. Takeda et al. / Chemosphere 40 (2000) 575±586
incinerators. Since there are many crematories without secondary combustion chambers, the crematories are considered as one of the largest emission sources. 6. Conclusion In this research, concentrations of PCDDs and PCDFs in emission gases from 10 crematories were measured. The relationship between dioxins and several factors such as structure, equipment and operational state of the crematory is discussed. Furthermore, total emission of PCDDs/DFs from crematories in Japan is estimated. Results are summarized as below: 1. Total concentration of PCDDs/DFs from a crematory was 2.2±290 ng/N m3 , and TEQ concentration was 0.0099±6.5 ng TEQ/N m3 . 2. Concentration of PCDFs was higher than that of PCDDs, especially T4CDFs were the highest and 2,3,7,8-T4CDF was detected in almost all samples. 3. For a homologue pattern of PCDFs, the concentration of T4CDFs was high and that of the higher chlorinated compounds was low. For that of PCDDs, two patterns were identi®ed: (i) a mountain shape pattern with peaks of H6CDDs, which is similar to the typical pattern of waste incinerators, and (ii) a pattern the same as the PCDFs pattern. 4. The total concentration of PCDDs/DFs from crematories whose dust concentration is less than 50 mg/N m3 tends to be low. 5. Total concentration of PCDDs/DFs was highest in the ®rst 20 min from the start. Although concentrations for middle 20 min and last 20 min followed,
dierences between the three values were not so large. 6. It was found that sex and age of dead body does not aect the concentration of PCDDs/DFs. 7. Existence of a dust collector, temperature of the secondary combustion chamber and the number of main combustion chambers connected to a secondary combustion chamber aected the concentration of PCDDs/DFs. 8. The total amount of PCDDs/DFs emitted from crematories in Japan was estimated to be 8.9 g TEQ/yr.
Acknowledgements This research was supported by Health Sciences Research Grants in FY1997 of Japanese Government. References Hiraoka, M., Okajima, S., 1994. Source control technologies in MSW incinerator plants. Organohalogen Compounds 19, 275±291. Eguchi, S., Takeda, N., Sakai, S., 1996. PCDDs/PCDFs emission from a crematory. Organohalogen Compounds 27, 127±132. Hutzinger, O., Fiedler, H., From source to exposure: some open questions. Chemosphere 27 (1±3), 121±129. The Working Group of Subcommittee, 1993. Air/technology of the Federal Government Federal State Pollution Control Committee, Germany: determination of requirements to limit emissions of dioxins and furans, pp. 127±129. Shimazaki, A., 1997. Kaso Gairon, third ed. Japan Society of Environmental Crematory, 165 pp.