Environ. Sci. Technol. 2008, 42, 75–80
Characterization of Polybrominated Dibenzo-p-Dioxins and Dibenzofurans in Different Atmospheric Environments L I N - C H I W A N G , * ,† C H E N G - H S I E N T S A I , ‡ GUO-PING CHANG-CHIEN,† AND CHUNG-HSIEN HUNG† Department of Chemical and Materials Engineering, Cheng Shiu University, 840, Chengching Road, Kaohsiung 833, Taiwan, ROC, and Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, 415, Chien-Kung Road, Kaohsiung 807, Taiwan, ROC
Received August 02, 2007. Revised manuscript received October 23, 2007. Accepted October 24, 2007.
Few studies have measured polybrominated dibenzo-pdioxins and dibenzofurans (PBDD/Fs) in the atmosphere. In this study, four categories of atmospheric environments, including rural (Kengting national park, Taitung county, and Yilan county), urban (north Kaohsiung city and south Taichung city), industrial (Lin-hai industrial park), and science park (Hsinchu science park) areas were investigated for their characteristics of 2,3,7,8-substituted PBDD/F and polychlorinated dibenzop-dioxins and dibenzofurans (PCDD/Fs). The elevated PCDD/F I-TEQ concentrations and higher ratio of PCDFs to PCDDs in the industrial areas reveal that the metallurgical facilities, including sinter plants, electric arc furnaces, secondary aluminum smelters, and secondary copper smelters, significantly influence their surrounding atmospheric environments. The mean PBDD/F concentrations in the atmosphere of the rural, urban, industrial, and science park areas were 11, 24, 46, and 95 fg/Nm3, respectively, while the corresponding mean TEQ concentrations were 2.7, 6.4, 12, and 31 fg TEQ/Nm3, respectively. The significantly high correlation (r ) 0.85, p ) 0.034) found between the PBDD/F and PCDD/F concentrations in the atmospheres of the industrial areas reveals that the metallurgical facilities are also the most likely PBDD/F emission sources in the industrial areas. The PBDD/F concentration in the science park area was ∼2-fold higher than that in the industrial areas, whereas PCDD/F I-TEQ concentration in the area was only 23% of that in the industrial areas. The elevated PBDD/F concentrations in the science park areas may be attributed to the use of polybrominated diphenyl ethers as brominated flame retardants in the electrical and electronics industries, which contribute to direct PBDD/F emissions into the environment. PBDFs were all much more dominant than PBDDs in the atmosphere, and their mass fractions increase with PBDD/F concentrations.
* Corresponding author tel: +886-7-7310606ext. 3921; fax: +8867-7332204; e-mail:
[email protected]. † Cheng Shiu University. ‡ National Kaohsiung University of Applied Sciences. 10.1021/es071924q CCC: $40.75
Published on Web 11/30/2007
2008 American Chemical Society
Introduction Concerns about polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) have increased because brominated flame retardants (BFRs) are extensively used in a variety of materials and are miscible with most plastics. Several potential routes for the release of PBDD/Fs into the environment have been proposed, including formation in the process of manufacturing BFRs, formation during the processing of BFRs with polymer resin, and incinerating waste which contains BFRs (1–3). Commercial mixtures of polybrominated diphenyl ethers (PBDEs) contain PBDFs as impurities at contents ranging from 257 to 49,600 ng/g, indicating that the use of PBDE mixtures can contribute to the direct emission of PBDFs into the environment (3). PBDDs were not detected at levels above the limit of detection (3). However, few studies have investigated the 2,3,7,8-substituted PBDD/F emission from the potential routes above. Our recent research has characterized 2,3,7,8-substituted PBDD/Fs in the stack flue gases of full-scale municipal solid waste incinerators (MSWIs) and several kinds of industrial waste incinerators (IWIs) (4). The concentration of PCDD/Fs in the stack flue gases of IWIs (0.0128–0.897 ng I-TEQ/Nm3) and MSWIs (0.0171–1.98 ng I-TEQ/Nm3) are in the same range. However, the elevated PBDD/F concentrations (18.2 pg/Nm3, 4.17 pg TEQ/Nm3) in the stack flue gases of the IWIs were eight times higher than those of MSWIs (2.28 pg/Nm3, 0.557 pg TEQ/Nm3) (4). Air concentrations of PCDD/Fs or polychlorinated biphenyls (PCBs) have been extensively measured at background (5–8), rural (7–10), residential (7, 11, 12), urban (7, 9, 11, 13), and industrial areas (7, 14, 15), as well as areas strongly influenced by emission sources (9, 13), heavy traffic areas (7, 12), and workplace environments (16, 17). Furthermore, PCDD/Fs in the atmosphere had been found to increase during the fall and winter in many studies (18–21). The increased demand for heating in the winter and the atmospheric concentration of hydroxyl radicals which varies significantly with latitude (22) are thought to be influential factors. However, no such seasonal trend was observed in an urbanized area of the UK (23). With regard to PBDD/Fs, only a few studies with limited samples have reported on the PBDD/F characteristics in the atmosphere (24–27). Hayakawa et al. (24) measured the PBDD/Fs (sum of mono to octa-BDD/Fs) (n ) 5) in the atmosphere of Kyoto, an urban city in Japan. The concentrations of particulate-phase PBDD/Fs ranged from 0.17 to 1.2 pg/m3, while those of the gas-phase PBDD/Fs ranged from 1.1 to 11 pg/m3. Most of the concentration was contributed by mono- to tri-BDFs. In airborne dust in Osaka, Japan, the concentrations of PBDFs (sum of tetra- to hexaBDFs) were 4.2-17 pg/m3 with no PBDDs detected (25). Another study reported that the concentration of PBDD/Fs (sum of 11 congeners) (n ) 1) in the atmosphere from the Osaka district was only 0.036 pg/m3 (27). In this study, the 2,3,7,8-substituted PBDD/F and PCDD/F characteristics in the atmosphere of rural, urban, industrial, and science park areas were investigated. The mass and TEQ ratios of the PBDD/F to PCDD/F concentrations in different atmospheric environments are presented and compared. Furthermore, the congener profiles of PBDD/Fs and PCDD/ Fs in the different atmospheric environments are discussed to reveal the possible emission sources.
Materials and Methods Sampling Areas. Air samples were collected from rural (R1-R5), urban (U1-U7), industrial (I1-I5), and science park VOL. 42, NO. 1, 2008 / ENVIRONMENTAL SCIENCE & TECHNOLOGY
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FIGURE 1. Sampling locations of the four categories of atmospheric environments. areas (S1-S2) during July, 2004 to November, 2005. Each area included 2–5 atmosphere sampling sites to obtain good representative samples and enough PBDD/F for analyses. The sampling information is detailed in Table S1 of the Supporting Information (SI), which shows that the atmospheric temperature and pressure during atmosphere sampling were between 18 and 31 °C and between 754 and 764 mmHg, respectively. The wind speeds were from 1.4 to 3.2 m/s. The meteorological data shows that the weather conditions during these sampling periods did not change too much. The sampling locations of the four categories of atmospheric environments are depicted in Figure 1. The rural areas (R1-R5) are situated in Kengting national park, Taitung county, and Yilan county, which are located at the southern tip, east coast, and northeast coast of Taiwan. There are a total of 15 atmosphere sampling sites (denoted as m) for these rural areas. The urban areas (U1-U7, m ) 27) are situated in northern Kaohsiung city (1.5 million inhabitants) and southern Taichung city (1 million inhabitants), which are the second and third largest cities in Taiwan, respectively. The Lin-hai industrial park, which is Taiwan’s largest metallurgical industrial park and is located at the southern end of Kaohsiung city, was investigated as the industrial areas (I1-I5, m ) 15). The region is clustered with metallurgical facilities, including sinter plants, electric arc furnaces (EAFs), secondary aluminum smelters (ALSs), and secondary copper smelters. Several incinerators, including one MSWI, one medical waste incinerator (MWI), and some IWIs, are also situated in this region (12, 28). The Hsinchu science park, which comprises semiconductor, optoelectronics, computer and peripheral, telecommunications, and consumer electronic appliance industries, the largest science park in Taiwan, was chosen to represent the science park area (S1 and S2, m ) 6). Sampling Procedures. All the ambient air samplings and chemical analyses in this study were carried out by our accredited laboratory in Taiwan. Each ambient air sample was collected using a PS-1 sampler (Graseby Andersen, GA) according to revised EPA Reference Method TO9A. The sampling flow rate was specified at ∼0.225 m3/min. Each sample was collected continuously for three consecutive days (sampling volume ) 972 m3). The PS-1 sampler was equipped with a quartz-fiber filter for sampling particulate-phase PCDD/Fs and PBDD/Fs, and a glass cartridge for sampling gas-phase PCDD/Fs and PBDD/Fs. The sampled air volumes were normalized to the standard condition of 760 mmHg and 298 K, and denoted as Nm3. Because the ranges of the atmospheric temperature and pressure during the atmo76
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sphere sampling were small, the change of the PCDD/F concentrations due to the normalization was less 1%. Some occasional events, like open burning of agricultural waste (29) and an Asian sand storm (30), were avoided during atmosphere sampling. Analytical Procedures. To measure both the PCDD/Fs and PBDD/Fs, after the extraction of the ambient air samples, the extracted solution was divided equally into flasks A and flasks B. All the A flasks were measured for PCDD/Fs individually. For the PBDD/F measurement, all the B flasks from the same investigated area were combined into one because of the detection limit. That is, one area had data for several PCDD/F and one PBDD/F ambient air sample. Compared to PCDD/Fs, which had 17 congeners reported, only 7 of the possible 17 2,3,7,8-substituted PBDD/F congeners were reported due to the lack of a standard. Detailed analytical procedures of PBDD/Fs and PCDD/Fs are given in the SI and our previous work (4, 7). Instrumental Analysis. A high-resolution gas chromatograph/high-resolution mass spectrometer (HRGC/HRMS) was used for PBDD/F and PCDD/F analyses. For PBDD/Fs, the HRGC (Hewlett-Packard 6970 Series gas chromatograph, CA) was equipped with an Rtx-5MS capillary column (L ) 30 m, i.d. ) 0.25 mm, film thickness ) 0.25 µm) (Restek, PA), and with a splitless injection. For PCDD/Fs, the column was changed to a DB-5MS fused silica capillary column (L ) 60 m, i.d. ) 0.25 mm, film thickness ) 0.25 µm) (J&W Scientific, CA). The HRMS (Micromass Autospec Ultima, Manchester, UK) mass spectrometer was equipped with a positive electron impact (EI+) source. The selected ion monitoring mode was used with a resolving power of 10,000. Detailed instrumental analysis parameters of PBDD/Fs and PCDD/Fs are given in the SI and our previous work (4, 7). Quality Assurance and Quality Control (QA/QC). Prior to sampling, polyurethane foam (PUF) was spiked with PCDD/F surrogate standards prelabeled with isotopes, including 37Cl42,3,7,8-TCDD, 13C12-1,2,3,4,7,8-HxCDD, 13C12-2,3,4,7,8-PeCDF, 13C -1,2,3,4,7,8-HxCDF, and 13C -1,2,3,4,7,8,9-HpCDF. The 12 12 recoveries of PCDD/F surrogate standards were 92%–115%, which met the criteria of 70%–130%, and reveal that no PCDD/F breakthrough occurred. Because no PBDD/F surrogate standards could be purchased, the sampler collection efficiency check for PBDD/Fs used the recoveries of the corresponding PCDD/F surrogate standards. The recoveries of PCDD/F internal standards, which were added to the samples before extraction, for the tetra- through hexachlorinated homologues were between 63% and 101%, which met the criteria of being within 40%–130%, while those for the hepta- and octachlorinated homologues were between
TABLE 1. PCDD/F Concentrations (Normalized To the Standard Condition of 760 mmHg and 298 K) in the Atmosphere of the Rural, Urban, Industrial, and Science Park Areas. sampling areas
rural areas (R1-R5) urban areas (U1-U7) industrial areas (I1-I5) science park areas (S1 and S2) m ) 15
sampling sites PCDD/Fs
m ) 27
m ) 15
m)6
mean
RSD %
mean
RSD %
mean
RSD %
mean
RSD %
PCDDs PCDFs PCDFs/PCDDs ratio
0.20 0.30 1.5
91 83 27
0.39 0.57 1.7
52 44 44
0.56 1.2 2.1
49 65 39
0.25 0.39 1.9
46 26 55
total PCDD/Fs (pg/Nm3)
0.50
83
0.96
44
1.7
58
0.63
28
0.029
45
0.060
33
0.15
82
0.033
15
0.031
44
0.064
33
0.16
81
0.036
15
total I-TEQ (pg
I-TEQ/Nm3)
total WHO-TEQ (pg WHO-TEQ/Nm3)
TABLE 2. PBDD/F Concentrations (Normalized To the Standard Condition of 760 mmHg and 298 K) and the Ratios of the PBDD/F to PCDD/F Concentrations in the Atmosphere of the Rural, Urban, Industrial, and Science Park Areas rural areas (R1-R5)
PBDD/Fs
2,3,7,8-TeBDD 1,2,3,7,8-PeBDD 1,2,3,4/6,7,8-HxBDD 1,2,3,7,8,9-HxBDD 2,3,7,8-TeBDF 1,2,3,7,8-PeBDF 2,3,4,7,8-PeBDF total (fg/Nm3) total TEQ (fg I-TEQ/Nm3)
PCDD/Fs
total (pg/Nm3) total TEQ (pg I-TEQ/Nm3)
ratio of PBDD/Fs to PCDD/Fs (percent)
urban areas (U1-U7)
industrial areas (I1-I5)
science park areas (S1 and S2)
mean
RSD (%)
mean
RSD (%)
mean
RSD (%)
0.28 0.33 0.60 0.10 3.2 3.1 3.5 11 2.7
130 99 46 170 57 89 57 61 61
1.1 1.7 3.4 0.78 5.8 5.2 6.3 24 6.4
54 52 54 70 32 37 27 22 23
1.3 1.8 3.0 0.83 10 13 16 46 12
23 55 76 92 34 42 24 29 22
0.96 0.060
44 33
1.7 0.15
58 82
2.6
27
2.9
23
15
41
46
91
35
0.50 0.029
83 45
mass ratio (%)
1.8
43
TEQ ratio (%)
8.7
48
56% and 104%, which met the criteria of being within 25%–130%. The recoveries of PBDD/F internal standards were between 55% and 114%, which met the criteria of being within 40%–130%. The recoveries of PCDD/F Precision and Recovery (PAR) standards, which were conducted for each sample batch, were 86%–123%, while those of PBDD/Fs PAR standards were 84%–118%, both meeting the criteria of being within 70%–130%. The limit of detection (LOD) in this study was defined as a signal-to-noise (S/N) greater than three, while the limit of quantification (LOQ) was defined as an S/N greater than ten. We had participated in the first round of the international intercalibration for PBDD/Fs and PBCDD/Fs in 2004. The result revealed that the performance of our method was acceptable for PBDD/F analysis.
Results and Discussion PCDD/F Concentrations. Table 1 lists the PCDD/F concentrations in the atmosphere of the rural, urban, industrial, and science park areas. Tables S2-S4 of the SI list more detailed PCDD/F concentrations in each investigated area in order of their PCDD/F I-TEQ concentrations. The PCDD/F concentrations of the rural areas (R1-R5) ranged from 0.022 to 0.051 pg I-TEQ/Nm3 (range of RSD: 6.1%-52%) (see SI) with a mean of 0.029 pg I-TEQ/Nm3 (RSD: 45%). For urban areas, the PCDD/F concentrations (U1-U7) ranged from 0.040 to 0.088 pg I-TEQ/Nm3 (range of RSD: 6.9%-39%) with a mean of 0.060 pg I-TEQ/Nm3 (RSD: 33%). The PCDD/F concentrations of the industrial areas (I1--I5) were from 0.067 to 0.28 pg I-TEQ/Nm3 (range of RSD: 10%-80%), with
11
22
11
mean 1.2 2.8 2.1 1.8 13 24 50 95 31 0.63 0.034
RSD (%) 79 38 12 140 110 91 38 56 43 18 8.5
a mean of 0.15 pg I-TEQ/Nm3 (RSD: 82%). The PCDD/F concentrations of the science park areas (S1 and S2) were 0.031-0.036 pg I-TEQ/Nm3 (range of RSD: 3.9%-20%), with a mean of 0.033 pg I-TEQ/Nm3 (RSD: 15%). The moderate RSD values reveal the great representativeness of each selected area. The PCDD/F concentrations obtained from these different atmospheric environments are comparable to our previous results (7, 12, 16) and those of other studies (9, 10, 31). Cleverly et al. (8) conducted long-term measurements of the atmospheric PCDD/F concentrations in rural and remote areas of the United States. The rural sites were in areas where crops and livestock are grown, while the remote sites were >100 km away from human PCDD/F sources. The PCDD/F concentrations in the rural areas (29 fg I-TEQ/Nm3) of the present study were about 2–5 times higher than those (6.4-15.4 fg I-TEQ/m3) found in the United States. The mean PCDD/F I-TEQ concentration in the industrial area was 5.0 ()0.15/0.029), 2.5 ()0.15/0.060), and 4.4 ()0.15/ 0.033) times higher than those of the rural, urban, and science park areas, respectively. The elevated PCDD/F I-TEQ concentration in the industrial area was attributed to the PCDD/F emissions from the metallurgical facilities, including EAFs, secondary ALSs, and sinter plants after conducting the principal component analyses and indicatory PCDD/F comparison (12). PBDD/F Concentrations. Because the toxic equivalency factors (TEFs) have not been determined for PBDD/Fs, the I-TEFs of PCDD/Fs were used for the corresponding conVOL. 42, NO. 1, 2008 / ENVIRONMENTAL SCIENCE & TECHNOLOGY
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FIGURE 2. PCDD/F and PBDD/F congener profiles in the atmosphere (fraction of total PCDD/F or PBDD/F mass concentration). geners of PBDD/Fs (4, 32–35) to calculate their toxicity in the atmosphere. The PBDD/F concentrations and the corresponding ratios (in percentage) of the PBDD/F to PCDD/F concentrations in the atmosphere of the rural, urban, industrial, and science park areas are shown in Table 2. More detailed data in each investigated area are listed in Tables S5-S8 of the SI. The mean PBDD/F mass concentrations (sum of 7 2,3,7,8-substituted congeners) in the atmosphere of the rural, urban, industrial, and science park areas were 11 (range: 3.4-20, RSD: 61%), 24 (range: 15-30, RSD: 22%), 46 (range: 28-58, RSD: 29%), and 95 fg/Nm3 (range: 58-130 fg/Nm3, RSD: 56%), respectively, while the corresponding mean TEQ concentrations in the atmosphere were 2.7 (range: 1.2-4.9, RSD: 61%), 6.4 (range: 3.9-7.7, RSD: 23%), 12 (range: 8.5-16, RSD: 22%) and 31 fg TEQ/Nm3 (range: 22-40 fg TEQ/ 78
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Nm3, RSD: 43%), respectively. The PBDD/F concentration (sum of 11 2,3,7,8-substituted congeners) in Osaka, Japan, (36 fg/m3, n ) 1) (19) was comparable to our findings in urban (24.3 fg/Nm3) and industrial areas (45.6 fg/Nm3). However, the PBDD/F concentrations (sum of 13 2,3,7,8substituted congeners) of 250-2300 fg/m3 (for total monoto octa-PBDD/F concentrations, 1760-12,100 fg/m3) in the atmosphere of Kyoto (n ) 5), Japan (24) were much higher than our findings. The mean PBDD/F concentration in the industrial areas was 4.1- ()46/11) and 1.9- ()46/24) fold on a mass basis, and 4.4- ()12/2.7) and 1.9- ()12/6.4) fold on a toxicity basis, higher than those of the rural and urban areas, respectively. The elevated level of PBDD/Fs in the industrial areas was close to that of PCDD/Fs (5.0- and 2.5-fold higher than the
PCDD/F I-TEQ concentration in the rural and urban areas, respectively). The Pearson correlation analyses revealed that only in the industrial areas was the PBDD/F concentration significantly correlated with the PCDD/F concentration (r ) 0.85, p ) 0.034) or with the logarithm of the PCDD/F concentration (r ) 0.89, p ) 0.023); the other areas did not have a the significant correlation, i.e. p > 0.05. The above results show that the PBDD/F and PCDD/F emission sources in the industrial area are similar, and are likely from the metallurgical facilities. However, no study was conducted on the PBDD/F characteristics in the stack flue gases of the metallurgical facilities, such as EAFs, secondary ALSs, and sinter plants. The PBDD/F concentration in the science park area was 2.1- ()95/46) fold on a mass basis and 2.5- ()31/12) fold on a toxicity basis higher than that of the industrial areas, whereas the PCDD/F I-TEQ concentration in the science park area was only 23% of that of the industrial areas. We speculated that the elevated PBDD/F concentrations in the science park area may be attributed to the use of PBDEs as BFRs in the electrical and electronics industries, which contribute to direct PBDD/F emission into the environment (3). Due to limitations in both cost and manpower, PBDEs in the atmosphere were not measured in this study. However, Chen et al. (36) observed substantially higher PBDE concentrations in the atmosphere (PBDD/Fs were not measured) of an area with a cluster of electronic/electrical equipment, plastics, and automobile manufacturing industries. The combined results of this study and that of Chen et al. (36) seem to be comparable with the results that obtained by Hayakawa et al. (24), which showed that the PBDD/F concentrations in the atmosphere correlated positively with PBDEs in Kyoto, Japan (24). The mean ratios (in percentage) of the PBDD/F to PCDD/F concentrations in the atmosphere of the rural, urban, industrial, and science park areas were 1.8% (range: 1.1%-3.0%),2.6%(range:1.9%-3.9%),2.9%(range:2.1%-3.9%), and 15% (range: 10%-19%), respectively, while their corresponding mean TEQ ratios (in percentage) were 8.7% (range: 4.9% -15%), 11% (range: 8.2%-15%), 11% (range: 4.8%-17%), and 91% (range: 68%-110%), respectively. Because the PBDD/F and PCDD/F concentrations were measured from the same air samples, the ratio of the PBDD/F to PCDD/F concentrations in the atmosphere depend on the local emission sources, and are not related to the meteorological conditions. Only in the atmosphere of the industrial areas was the TEQ ratio of the PBDD/F to PCDD/F concentrations significantly negatively correlated with the PCDD/F I-TEQ concentration (r ) -0.84, p ) 0.036). The TEQ ratio was also significantly negatively correlated with the log PCDD/F I-TEQ concentration (r ) -0.89, p ) 0.020). Our previous study showed that in poor combustion conditions, both the PCDD/F and PBDD/F emissions from MSWIs increased, but the increase of PCDD/Fs is larger than that of PBDD/Fs (4). Consequently, the declining ratios of the PBDD/F to PCDD/F concentrations with increasing PCDD/F I-TEQ concentration in the atmosphere of the industrial areas may result from incomplete combustion at the metallurgical facilities. The TEQ contribution of PBDD/Fs to total TEQ in the atmosphere was limited (only 11% of PCDD/F I-TEQ, even for industrial areas), except for the science park area, where the TEQ contribution of PBDD/F was significant. Comparing PBDD/Fs to coplanar PCBs, the TEQ contribution of the coplanar PCBs ranged from 5.0% to 9.4% of the PCDD/F I-TEQ contribution for the ambient air samples taken at an urban site, a rural site, and two village sites, which relied on domestic burning for space heating in northwest England (9). Kurokawa et al. (37) also reported similar results; the ratio was about 4.9% in the atmosphere of three urban sites.
Consequently, the TEQ contribution of PBDD/Fs in the atmosphere is comparable to that of coplanar PCBs, except in the science park areas. PCDD/F and PBDD/F Congener Profiles. The congener profiles of the seventeen 2,3,7,8 chlorinated substituted PCDD/Fs and the seven 2,3,7,8 brominated substituted PBDD/Fs (mean ( SD) detected in the atmosphere are shown in Figure 2. The profiles were calculated according to the fraction (%) of each congener to the total PCDD/F mass concentration (or total PBDD/Fs). The PCDD/F congener profiles of the rural, urban, industrial, and science park areas show that the most abundant congeners in the atmosphere were 1,2,3,4,6,7,8- HpCDD, OCDD, 1,2,3,4,6,7,8- HpCDF, and OCDF, which are consistent with those found in other studies (10, 38, 39). However, the PCDD/F congener profiles obtained in this study are different from those in rural and remote areas of the United States (8), in which the PCDD/F patterns were a consequence of the atmospheric “weathering” effect. They found that 1,2,3,4,6,7,8-HpCDD (10%-11%) and OCDD (36%-37%)dominatedthecongenerprofile,while1,2,3,4,6,7,8HpCDF and OCDF only represented 1.9%-2.7% and 2%-6% of the total PCDD/F concentration, respectively. Together, these top four congeners accounted for 50%–55% of all PCDD/F present in rural and remote area air. Figure 2 also shows that the low chlorinated substituted PCDFs, such as 2,3,7,8-TeCDF, 1,2,3,7,8-PeCDF, and 2,3,4,7,8PeCDF, are more dominant in the atmosphere of the industrial areas (21%) than in rural (14%), urban (15%), and science park areas (10%). These congeners are the indicatory PCDD/Fs of EAFs, secondary ALSs, and sinter plants (12), revealing the strong influence of metallurgical facilities on the PCDD/F concentration in the atmosphere. With regard to PBDD/Fs, PBDFs are more dominant than PBDDs in all the atmospheric environments. Hayakawa et al. (24) also reported that PBDFs were predominant, with PBDDs detected at only trace levels in the atmosphere of Kyoto, Japan. The mass fractions of PBDFs in the rural, urban, industrial, and science park areas were 86%, 71%, 85%, and 90%, respectively. The fractions increased with PBDD/F concentration, except in rural areas, where the high PBDF fractions resulted from the low concentration and several measurements below the detection limit in PBDD congeners. This shows that PBDFs should be more dominant for significant PBDD/F emission sources. Our previous study reported that the stack flue gases of MSWIs are dominated by PBDDs, while those of IWIs are dominated by PBDFs (4). Consequently, MSWIs are less significant PBDD/F emission sources compared to others.
Acknowledgments We thank the National Science Council of Taiwan for supporting this research work under Grant NSC-94-2218E-230-005.
Supporting Information Available Detailed sampling information, detailed PCDD/F and PBDD/F concentrations, and the ratios of the PBDD/F to PCDD/F concentrations in the atmosphere of each investigated area. This material is available free of charge via the Internet at http://pubs.acs.org.
Literature Cited (1) Thoma, H.; Hauschulz, G.; Knorr, E.; Hutzinger, O. Polybrominated dibenzofurans (PBDFs) and dibenzodioxins (PBDDs) from the pyrolysis of some flame retardants neat brominated diphenylethers, biphenyl and plastic mixtures of these compounds. Chemosphere 1987, 16, 277–285. (2) Sakai, S.; Watanabe, J.; Honda, Y.; Takatsuki, H.; Aoki, I.; Futamatsu, M.; Shiozaki, K. Combustion of brominated flame retardants and behavior of its byproducts. Chemosphere 2001, 42, 519–531. VOL. 42, NO. 1, 2008 / ENVIRONMENTAL SCIENCE & TECHNOLOGY
9
79
(3) Hanari, N.; Kannan, K.; Miyake, Y.; Okazawa, T.; Kodavanti, P. R. S.; Aldous, K. M.; Yamashita, N. Occurrence of polybrominated biphenyls, polybrominated dibenzo-p-dioxins, and polybrominated dibenzofurans as impurities in commercial polybrominated diphenyl ether mixtures. Environ. Sci. Technol. 2006, 40, 4400–4405. (4) Wang, L. C.; Chang-Chien, G. P. Characterizing the emissions of polybrominated dibenzo-p-dioxins and dibenzofurans from municipal and industrial waste incinerators. Environ. Sci. Technol. 2007, 41, 1159–1165. (5) Baker, J. I.; Hites, R. A. Polychlorinated dibenzo-p-dioxins and dibenzofurans in the remote north Atlantic marine atmosphere. Environ. Sci. Technol. 1999, 33, 14–20. (6) Lohmann, R.; Ockenden, W. A.; Shears, J.; Jones, K. C. Atmospheric distribution of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs), and non-ortho biphenyls (PCBs) along a north-south Atlantic transect. Environ. Sci. Technol. 2001, 35, 4046–4053. (7) Wang, L. C.; Lee, W. J.; Lee, W. S.; Chang-Chien, G. P.; Tsai, P. J. Characterizing the emissions of polychlorinated dibenzo-pdioxins and dibenzofurans from crematories and their impacts to the surrounding environment. Environ. Sci. Technol. 2003, 37, 62–67. (8) Cleverly, D.; Ferrario, J.; Byrne, C.; Riggs, K.; Joseph, D.; Hartford, P. A general indication of the contemporary background levels of PCDDs, PCDFs, and coplanar PCBs in the ambient air over rural and remote areas of the United States. Environ. Sci. Technol. 2007, 41, 1537–1544. (9) Lohmann, R.; Northcott, G. L.; Jones, K. C. Assessing the contribution of diffuse domestic burning as a source of PCDD/ Fs, PCBs, and PAHs to the U.K. atmosphere. Environ. Sci. Technol. 2000, 34, 2892–2899. (10) Lee, R. G. M.; Green, N. J. L.; Lohmann, R.; Jones, K. C. Seasonal, anthropogenic, air mass, and meteorological influences on the atmospheric concentrations of polychlorinated dibenzo-pdioxins and dibenzofurans (PCDD/Fs): evidence for the importance of diffuse combustion sources. Environ. Sci. Technol. 1999, 33, 2864–2871. (11) Lohmann, R.; Corrigan, B. P.; Howsam, M.; Jones, K. C.; Ockenden, W. A. Further developments in the use of semipermeable membrane devices (SPMDs) as passive air samplers for persistent organic pollutants: field application in a spatial survey of PCDD/Fs and PAHs. Environ. Sci. Technol. 2001, 35, 2576– 2582. (12) Lee, W. S.; Chang-Chien, G. P.; Wang, L. C.; Lee, W. J.; Tsai, P. J.; Wu, K. Y.; Lin, C. Source identification of PCDD/Fs for various atmospheric environments in a highly industrialized city. Environ. Sci. Technol. 2004, 38, 4937–4944. (13) Jones, K. C.; Duarte-Davidson, R. Transfers of airborne PCDD/ Fs to bulk deposition collectors and herbage. Environ. Sci. Technol. 1997, 31, 2937–2943. (14) Wethington, D. M., III; Hornbuckle, K. C. Milwaukee, Wisconsin, as a source of atmospheric PCBs to Lake Michigan. Environ. Sci. Technol. 2005, 39, 57–63. (15) Yu, L.; Mai, B.; Meng, X.; Bi, X.; Sheng, G.; Fu, J.; Peng, P. Particlebound polychlorinated dibenzo-p-dioxins and dibenzofurans in the atmosphere of Guangzhou, China. Atmos. Environ. 2006, 40, 96–108. (16) Chen, S. J.; Lee, W. S.; Chang-Chien, G. P.; Wang, L. C.; Lee, W. J.; Kao, J. H. Characterizing polychlorinated dibenzo-pdioxins and dibenzofurans in the surrounding environment and workplace of a secondary aluminum smelter. Atmos. Environ. 2004, 38, 3729–3732. (17) Shih, M.; Lee, W. J.; Shih, T. S.; Huang, S. L.; Chang-Chien, G. P.; Wang, L. C. Characterization of dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the atmosphere of different workplaces of a sinter plant. Sci. Total Environ. 2006, 366, 197–205. (18) König, J.; Theisen, J.; Günther, W. J.; Liebl, K. H.; Büchen, M. Ambient air levels of polychlorinated dibenzofurans and dibenzo(p)dioxins at different sites in Hessen. Chemosphere 1993, 26, 851–861. (19) Sugita, K.; Asada, S.; Yokochi, T.; Okazawa, T.; Ono, M.; Goto, S. Survey of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and polychlorinated biphenyls in urban air. Chemosphere 1994, 29, 2215–2221. (20) Fiedler, H.; Swerev, M.; Nordsieck, H.; Dörr, G.; Hutzinger, O. Long-term ambient air measurements of PCDD/PCDF in southern Germany (1993–1996). Organohalogen Compd. 1997, 33, 93–98.
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9
ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 42, NO. 1, 2008
(21) Fiedler, H.; Lau, C.; Cooper, K.; Andersson, R.; Hjelt, M.; Rappe, C. PCDD/PCDF in the atmosphere of southern Mississippi, USA. Organohalogen Compd. 1997, 33, 122–127. (22) Spivakovsky, C. M.; Logan, J. A.; Montzka, S. A.; Balkanski, Y. J.; Foreman-Fowler, M.; Jones, D. B. A.; Horowitz, L. W.; Fusco, A. C.; Brenninkmeijer, C. A. M.; Prather, M. J.; Wofsy, S. C.; McElroy, M. B. Three-dimensional climatological distribution of tropospheric OH: update and evaluation. J. Geophys. Res. 2000, 105, 8931–8980. (23) Jones, K. C.; Duarte-Davidson, R. Transfer of airborne PCDD/ Fs to bulk deposition collectors and herbage. Environ. Sci. Technol. 1997, 31, 2937–2943. (24) Hayakawa, K.; Takatsuki, H.; Watanabe, I.; Sakai, S. Polybrominated diphenyl ethers (PBDEs), polybrominated dibenzop-dioxins/dibenzofurans (PBDD/Fs) and monobromo-polychlorinated dibenzo-p-dioxins/dibenzofurans (MoBPXDD/Fs) in the atmosphere and bulk deposition in Kyoto, Japan. Chemosphere 2004, 57, 343–356. (25) Watanabe, I.; Kawano, M.; Tatsukawa, R. Polybrominated and mixed polybromo/chlorinated dibenzo-p-dioxins and -dibenzofurans in the Japanese environment. Organohalogen Compd. 1995, 24, 337–340. (26) Watanabe, I.; Kawano, M.; Wang, Y.; Chen, Y.; Tatsukawa, R. Polybrominated dibenzo-p-dioxins (PBDDs) and-dibenzofurans (PBDFs) in atmospheric air in Taiwan and Japan. Organohalogen Compd. 1992, 9, 309–312. (27) Ohta, S.; Nakao, T.; Nishimura, H.; Okumura, T.; Aozasa, O.; Miyata, H. Contamination levels of PBDEs, TBBPA, PCDDs/ DFs, PBDDs/DFs and PXDDs/DFs in the environment of Japan. Organohalogen Compd. 2002, 57, 57–60. (28) Kao, W. Y.; Ma, H. W; Wang, L. C.; Chang-Chien, G. P. Sitespecific health risk assessment of dioxins and furans in an industrial region with numerous emission sources. J. Hazard. Mater. 2007, 145, 471–481. (29) Kao, J. H.; Chen, K. S.; Tsai, C. H.; Li, H. W.; Chang-Chien, G. P. Effects of burnings of wax apple stubble and rice straw on polychlorinated dibenzo-p-dioxin and dibenzofuran concentrations in air and soil. J. Air Waste Manage. Assoc. 2007, 57, 457–464. (30) Chi, K. H.; Wang, H. S.; Chang, M. B.; Lin, N. H. Evaluation of dioxin-like pollutants in ambient air via long range transport. Asian Aerosol Conference, Taiwan, 2007. (31) Sin, W. M.; Choi, Y. Y.; Louie, K. K. A study of polychlorinated dibenzo-p-dioxins and dibenzofurans in the atmosphere of Hong Kong. Chemosphere 2002, 47, 647–653. (32) World Health Organization. Polybrominated Dibenzo-p-Dioxins and Dibenzofurans, Environmental Health Criteria 205 ; International Programme on Chemical Safety (WHO/IPCS): Geneva, Switzerland, 1998. (33) Schacht, U.; Gras, B.; Sievers, S. Determination of polybrominated and polychlorinated dibenzodioxins and -furans in various environmentally relevant materials. Organohalogen Compd. 1995, 22, 325–334 (in German). (34) Litten, S.; Mcchesney, D. J.; Hamilton, M. C.; Fowler, B. Destruction of the World Trade Center and PCBs, PBDEs, PCDD/ Fs, PBDD/Fs, and chlorinated biphenylenes in water, sediment, and sewage sludge. Environ. Sci. Technol. 2003, 37, 5502–5510. (35) Ashizuka, Y.; Nakagawa, R.; Tobiishi, K.; Hori, T.; Iida, T. Determination of polybrominated diphenyl ethers and polybrominated dibenzo-p-dioxins/dibenzofurans in marine products. J. Agric. Food Chem. 2005, 53, 3807–3813. (36) Chen, L. G.; Mai, B. X.; Bi, X. H.; Chen, S. J.; Wang, X. M.; Ran, Y.; Luo, X. J.; Sheng, G. Y.; Fu, J. M.; Zeng, E. Y. Concentration levels, compositional profiles, and gas-particle partitioning of polybrominated diphenyl ethers in the atmosphere of an urban city in south China. Environ. Sci. Technol. 2006, 40, 1190–1196. (37) Kurokawa, Y.; Matsueda, T.; Nakamura, M.; Takada, S.; Fukamachi, K. Characterization of non-ortho coplanar PCBs, polychlorinated dibenzo-p-dioxins and dibenzofurans in the atmosphere. Chemosphere 1996, 32, 491–500. (38) Coleman, P. J.; Lee, R. G. M.; Alcock, R. E.; Jones, K. C. Observations on PAH, PCB, and PCDD/F trends in U.K. urban air 1991–1995. Environ. Sci. Technol. 1997, 31, 2120–2124. (39) Abad, E.; Caixach, J.; Rivera, J. PCDD/F from emission sources and ambient air in northeast Spain. Chemosphere 1997, 35, 453–456.
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