Chemosphere 73 (2008) 865–872
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Chemosphere j o u r n a l h o m e p a g e : w w w . e l s e v i e r. c o m / l o c a t e / ch e m o s p h e r e
Congener-specific analysis of non-dioxin-like polychlorinated biphenyls in blood collected from 127 elderly residents in Nakagawa Town, Fukuoka Prefecture, Japan Takashi Todaka a,*, Tsuguhide Hori b, Hironori Hirakawa b, Jumboku Kajiwara b, Daisuke Yasutake b, Daisuke Onozuka b, Takao Iida b, Masutaka Furue a a b
Department of Dermatology, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582, Japan Fukuoka Institute of Health and Environmental Sciences, Mukaizano 39, Dazaifu-shi, Fukuoka 818-0135, Japan
a r t i c l e
i n f o
Article history: Received 23 Feburary 2008 Received in revised form 19 July 2008 Accepted 21 July 2008 Available online 2 September 2008 Keywords: Polychlorinated biphenyls Elderly man Elderly woman Nakagawa Town Congener-specific analysis Human blood
a b s t r a c t We conducted congener-specific analysis of non-dioxin-like polychlorinated biphenyls (non-dioxin-like PCBs) in blood collected in February 2004 from 127 elderly residents living in Nakagawa Town, Fukuoka Prefecture, Japan. The present study is one of the few studies in which 56 non-dioxin-like PCBs cong eners were measured in human blood. Of the 127 elderly residents, 51 were men (mean: 68.1 years) and 76 were women (mean: 68.1 years). Among 197 non-dioxin-like PCB congeners, 56 were identified in the blood of elderly residents. The arithmetic mean total concentrations of 56 non-dioxin-like PCBs congeners in the blood of elderly men and women in Nakagawa Town were 419 (median: 378) and 363 (median: 323) ng g¡1 lipid, respectively, and the concentrations were in the range of 172–1102 and 119–1226 ng g¡1 lipid, respectively, indicating that the total concentrations in elderly men are signif icantly higher than those in elderly women. The contamination of non-dioxin-like PCBs in the blood of elderly men and women in Fukuoka Prefecture was found to have decreased compared to past levels. The ratios of hexachlorinated biphenyls (hexaCBs) to the total concentrations of 56 non-dioxin-like PCBs cong eners in the blood of elderly men and women were 44.6% and 45.6%, respectively, which was particularly high compared with those of other congeners. 2,29,4,49,5,59-HexaCB (#153) among hexaCBs congeners, the most abundant congener in the blood of elderly men and women, contributed approximately 23.0% and 23.5% to the total concentrations of 56 non-dioxin-like PCBs congeners, respectively. Furthermore, 2,29,3,4,49,59-hexaCB (#138), 2,3,39,49,5,6-hexaCB (#163)/2,3,39,49,59,6-hexaCB (#164), 2,29,3,4,49,5,59heptaCB (#180), and 2,29,3,4,49,5,69-heptaCB (#182)/2,29,3,49,5,59,6-heptaCB (#187) also showed high ratios to the total concentrations of 56 non-dioxin-like PCBs congeners detected in the blood of elderly men and women. A statistical examination of the relationship between the total concentrations of 56 non-dioxin-like PCBs congeners in blood and the age of elderly residents who were over 60 years indi cated statistically significant correlations between the total concentrations of these PCBs congeners and the age of elderly women. However, similar correlations were not observed in elderly men. The results of the present study have indicated the current levels of non-dioxin-like PCBs in the blood of elderly men and women in Fukuoka Prefecture, Japan and can be used as baseline data for those over age 60. © 2008 Elsevier Ltd. All rights reserved.
1. Introduction Polychlorinated biphenyls (PCBs) are important members of the group of environmental contaminants know as persistent organic pollutants (POPs). PCBs form a family of 209 congeners differing in number (mono, di, tri, tetra, penta, hexa, hepta, octa, nona, and deca) and position (2,29,3,3’,4,4’,5,59,6, and 69) of the chlorine atoms on the two basic benzene rings. When these PCBs are released into the environment, PCBs congeners are becoming concentrated in * Corresponding author. Tel.: +81 92 921 9946; fax: +81 92 928 1203. E-mail address: todaka@fihes.pref.fukuoka.jp (T. Todaka). 0045-6535/$ - see front matter © 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.chemosphere.2008.07.058
the biota through food chains and are accumulating in the human body primarily via food (Deutch et al., 2004; Donato et al., 2006). Among 209 PCBs congeners, 12 PCBs that have the toxic equiva lency factors (TEF) proposed as dioxin-like PCBs are assumed to possess dioxin-like PCBs toxicities (Van den Berg et al., 1998, 2006). However, the toxicities have been suggested not only with dioxinlike PCBs but also with non-dioxin-like PCBs, and can be viewed as non-dioxin-like PCBs toxicities that are not mediated by the arylhydrocarbon receptor system (Kakeyama and Tohyama, 2003). Studies in humans and other vertebrates have demonstrated that exposure to non-dioxin-like PCBs may elicit many adverse health effects such as disruption of thyroxin function (Collins and Capen,
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1980; Ness et al., 1993; Crofton et al., 2000), disturbance of neu ral transmission (Seegal et al., 1990; Tilson and Kodavanti, 1998; Hussain et al., 2000), and impairment of learning performance (Rice and Hayward, 1997, 1999; Roegge et al., 2000). Therefore, sur vey studies of non-dioxin-like PCBs in the blood to elucidate the influence of these PCBs congeners on human health are necessary. Yusho poisoning occurred in western Japan in 1968 (Kuratsune et al., 1996). Although almost all of the typical symptoms affecting Yusho patients have improved, some patients are still afflicted with subjective symptoms. Since the outbreak of Yusho, medical care services and health examination of the subjects have been carried out by the study group of Yusho. To obtain more useful data for evaluating the concentrations of polychlorinated dibenzo-p-diox ins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho polychlorinated biphenyls (non-ortho PCBs), mono-ortho polychlo rinated biphenyls (mono-ortho PCBs), and non-dioxin-like PCBs in the blood of Yusho patients, it is necessary to measure the con centrations of there compounds in the blood of normal controls unaffected by Yusho living in Fukuoka Prefecture whose ages were similar to those of the Yusho patients and to compare the results between Yusho patients and normal controls. We measured the concentrations of PCDDs, PCDFs, and dioxin-like PCBs in blood col lected from 279, 269, 242, and 237 Yusho patients during medical check-ups performed the period from 2002 to 2005, respectively (Todaka et al., 2005a, 2007a). We also measured the concentra tions of there dioxin-like compounds in the blood of 127 normal controls living in Nakagawa Town, Fukuoka Prefecture in 2004 (Todaka et al., 2007b). However, the full congener-specific concen trations of non-dioxin-like PCBs in the bloods of Yusho patients and normal controls have not been measured for the Yusho study until now. Data from congener profiles regarding non-dioxin-like PCBs in the blood for the Yusho study may provide us with newly important information related to the exposure evaluation of Yusho patients. Moreover, although exposure studies regarding nondioxin-like PCBs in human blood have been reported for the last several decades, the published data showing the full congener-spe cific concentrations of non-dioxin-like PCBs are limited. In the present study, we measured the concentrations of nondioxin-like PCBs in blood samples, from which PCDDs, PCDFs, and dioxin-like PCBs were measured in a previous study, collected in February 2004 from 127 elderly residents living in Nakagawa Town
of Fukuoka Prefecture, Japan. The objectives of our primary study were: (1) to determine the current levels of non-dioxin-like PCBs in the blood of elderly residents in Nakagawa Town, Japan, and (2) to compare the concentrations in those samples with recently reported levels. 2. Materials and methods 2.1. Sampling Fukuoka Prefecture is located in the southwestern part of the Japanese archipelago that extends from north to south. Fukuoka Prefecture consists of a total of 66 characteristic municipalities, including Nakagawa Town, which is located in the southwestern part of Fukuoka City and has a population of 48 000 (Fig. 1). All the subjects participating in this study were native Japanese and were residents of Nakagawa Town. The blood samples were collected in February 2004 from 127 elderly residents, from whom informed consent was obtained. Among the 127 elderly residents, 51 were men and 76 were women. The ages of the elderly men and women ranged from 60 to 79 years (mean: 68.1, median: 68.0) and 60–6 years (mean: 68.1, median: 67.0), respectively. Blood samples of 10 mL were collected using a vacuum blood-collecting pipe contain ing heparin and stored at 4 °C until analysis for the concentrations of non-dioxin-like PCBs. 2.2. Materials Native congeners of non-dioxin-like PCBs were purchased from Wellington Laboratories (Guelph, Ontario, Canada). [13C12]congeners of non-dioxin-like PCBs as internal standards, were also purchased from Wellington Laboratories. An active carbon col umn was prepared as follows: active carbon was purchased from Nacalai Tesque (Kyoto, Japan), refluxed three times with toluene for 1 h, and dried in vacuum, after which 500 mg of the active car bon was mixed with 500 g of anhydrous sodium sulfate (Wako Pure Chemical Industries, Ltd., Tokyo, Japan). A silver nitrate/sil ica gel was purchased from Wako Pure Chemical Industries, Ltd. An active carbon-dispersed silicagel was purchased from Kanto Chemical Industries, Ltd., Tokyo, Japan. All reagents and solvents used in this experiment were of the analytic grade of dioxin that
Nakagawa Town
Fig. 1. Map showing the location of Nakagawa Town in Fukuoka Prefecture, Japan.
T. Todaka et al. / Chemosphere 73 (2008) 865–872
is commercially available. All glassware instruments used in this experiment were treated in a high-temperature oven (ALP Co. Ltd., Tokyo, Japan) at 450 °C for 6 h. 2.3. Sample preparation The extraction of lipids from the blood samples was performed using a previously reported method (Todaka et al., 2003; Iida and Todaka, 2003; Todaka et al., 2005b; Hori et al., 2005). The extract was concentrated to near dryness, and the lipid contents were determined gravimetrically. The extracted lipid was used to carry out the clean-up procedure. The lipid were dissolved in n-hexane (5 mL) and treated with concentrated sulfuric acid (3 mL). The sep arated hexane layer was applied to a column that linked a silver nitrate/silica gel column (0.5 g) and an active carbon sodium sulfate column (0.5 g), and it was separated into two fractions. The first fraction, containing mono-ortho PCBs and non-dioxin-like PCBs, was eluted with 15 mL of hexane and 10 mL of 10% (v/v) dichloro methane/n-hexane. PCDDs, PCDFs, and non-ortho PCBs were eluted with 25 mL of toluene as the second fraction. The first fraction was concentrated to near dryness with a multiple sample concentrator (BUCHI, Labortechnik AG, Flawil, Switzerland) and further purified using gel permeation chromatography (GPC) on a MSpak GF-310 4D column (4.6 £ 150 mm, Showa Denko K.K., Kanagawa, Japan) equilibrated with acetone at a flow rate of 0.1 mL min¡1. The GPC apparatus consisted of a PU614-F Pump, a UV702 Detector, a MIDAS Autosampler, and a FC 693 Fraction collector from GL Sciences Inc., Tokyo, Japan. The elution profile was monitored for absorbance at 220 nm, and the peak was determined on a SIC chromatocorder 12 (System Instrument Co. Ltd., Tokyo, Japan). The fractions containing mono-ortho PCBs and non-dioxin-like PCBs, which were purified by GPC, were concentrated to near dryness and the syringe standard was added. 2.4. Analysis of non-dioxin-like PCBs Congener-specific analysis of non-dioxin-like PCBs was mea sured using a high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) (Hori et al., 2005). The analytic conditions were as follows: the gas chromatograph was an HP6890 A (Hewlett–Packard, USA, CA) equipped with an Autospec Ultima, (Micromass Ltd., Manchester, UK); the column used was a HT-8-PCB column, 0.25 mm i.d. £ 60 m (SGE Ltd.); the column was heated from 130 °C to 220 °C at a rate of 20 °C min¡1, 220–280 °C at a rate of 3 °C min¡1, 280–300 °C at a rate of 20 °C min¡1. The injection temperature and ion source temperature were both maintained at 280 °C, and the carrier gas (helium) flow rate (constant flow) was 1.3 mL min¡1. The ionizing current, ionizing energy, accelerating voltage, and trap current were 750 lA, 40 eV, 8.0 kV, and 750 lA, respectively. PCBs were analyzed in a single-ion record mode. The resolution was maintained at 10 000 at 5%. 2.5. Quality control The limit of detection (LOD) for each congener of non-dioxinlike PCBs was determined at a signal-to-noise ratio of three on the chromatogram of a standard sample. The limit of quantifica tion for each congener of non-dioxin-like PCBs was assessed at 0.03 pg g¡1. To evaluate the accuracy and reliability in the conge ner-specific analysis of PCBs, our laboratory in 2007 prepared human blood samples for quality control and attempted to carry out a quality control study for the analysis of these PCBs congen ers in human blood. Measurements of 56 non-dioxin-like PCBs congeners that were measured in the present study among 197 non-dioxin-like PCBs congeners requested from three different analysis organizations and their results were compared with our
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results. It was confirmed that the results obtained by our labora tories were almost identical to those obtained by the three differ ent analysis organizations. The average variation among the total non-dioxin-like PCBs levels in human blood samples obtained by four laboratories was within 10% and was considered an accept able difference. In addition, our laboratory’s analytical method for non-dioxin-like PCBs demonstrated high reproducibility based on experiments conducted using the same control blood sample for ten weeks. These findings indicate that our laboratory’s analytical method for non-dioxin-like PCBs in human blood provides correct results. 2.6. Data analysis To estimate the total concentration, we introduced ND (less than the detection limit) values to half values of the detection limit. The statistical analysis was conducted using Mann-Whitney’s U test and Spearman’s rank correlation in the software program from SAS Institute (SAS Inc.). Significant probabilities (p values) were calculated for the respective number of samples analyzed. A signif icance level of 0.05 was used for all tests. 3. Results and discussion 3.1. Concentrations of non-dioxin-like PCBs in blood 209 PCBs congeners consist of 12 dioxin-like PCBs and 197 non-dioxin-like PCBs. Among these 197 non-dioxin-like PCBs congeners, 56 were identified in the blood of elderly residents in the present study (Table 1). Hirai et al. has reported that 85 nondioxin-like PCBs congeners were detected in blood collected from 24 healthy Japanese volunteers (12 men and 12 women; age range 25–6 years) (Hirai et al., 2005). The congener pattern of non-dioxinlike PCBs in the present study is comparable to that reported by Hirai et al. (2005). In the 85 non-dioxin-like PCBs congeners reported by Hirai et al. (2005), the total concentration of 55 congen ers (PCB 28, 44, 47/48, 49, 52/69, 56/60, 63, 66, 70, 71, 74, 85, 87, 92, 93/95/98, 99, 101, 107/108, 110, 117, 128, 130, 132, 134, 135, 137, 138, 139, 141, 146, 147, 151, 153, 163/164, 170, 172, 177, 178, 179, 180, 181, 182/187, 183, 191, 194, 195, 196/203, 198/201, 200, 202, 205, 206, 207, 208, and 209) that were commonly detected in the present study contributed approximately 96% of the total concentrations of 85 congeners. These 55 congeners may be considered to be the pre dominant congeners of non-dioxin-like PCBs in humans. The arithmetic mean total concentrations of 56 non-dioxin-like PCBs congeners in the blood of elderly men and women in Nakagawa Town, Fukuoka Prefecture, Japan were 419 (median: 378) and 363 (median: 323) ng g¡1 lipid, respectively, and the concentrations were in the range of 172–102 and 119–1226 ng g¡1 lipid, respectively, indi cating that the total concentrations in elderly men are significantly higher than those in elderly women (p = 0.031) (Table 1). These results are similar to those recently reported in Japan (Masuda et al., 2005). This difference between men and women may be attributable to the partial excretion of non-dioxin-like PCBs accumulating in the maternal body by delivery and possibly sex differences regarding the enzyme that catalyzes the metabolism of non-dioxin-like PCBs in humans. Indicator PCBs (PCB 28, 52, 101, 138, 153, and 180) have been selected by the European Food Safety Authority as the major congen ers that are almost always present in various sample matrices with high concentrations. The arithmetic mean total concentrations of indi cator PCBs congeners in the blood of elderly men and women were 94–34 (mean: 214, median: 189) and 58–91 (mean: 184, median: 160) ng g¡1 lipid, respectively, indicating that the total concentrations of indicator PCBs in elderly men were significantly higher than those in elderly women (p = 0.028) (Table 1). These results are also similar to those recently reported in Japan (Masuda et al., 2005).
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Table 1 Concentrations of non-dioxin-like PCBs in the blood of 127 elderly residents collected in Nakagawa Town, Fukuoka Prefecture, Japan IUPAC#
Elderly men (n = 51)
Elderly women (n = 76)
Mean
Median
SD
Min.
Max.
Mean
Median
SD
Min.
Max.
2.6 0.0
2.1 0.0
1.5 0.0
0.8 0.0
6.5 0.1
2.6 0.0
2.0 0.0
1.8 0.0
1.0 0.0
11 0.1
TetraCB-44 TetraCBs-47/48 TetraCB-49 TetraCBs-52/69a TetraCBs-56/60 TetraCB-63 TetraCB-66 TetraCB-70 TetraCB-71 TetraCB-74
0.5 0.6 0.3 1.3 0.9 0.1 2.5 0.3 0.2 16
0.5 0.6 0.3 1.2 0.6 0.1 1.7 0.2 0.2 14
0.1 0.2 0.1 0.8 0.6 0.1 1.8 0.1 0.1 8.5
0.2 0.2 0.1 0.4 0.2 0.0 0.4 0.1 0.0 3.5
0.8 1.3 0.6 5.8 2.8 0.5 7.1 0.6 0.4 40
0.5 0.6 0.3 1.3 0.9 0.2 2.3 0.3 0.2 22
0.5 0.6 0.3 1.0 0.7 0.1 1.8 0.3 0.2 20
0.2 0.2 0.1 0.9 0.8 0.1 1.9 0.1 0.1 12
0.1 0.3 0.1 0.4 0.2 0.0 0.7 0.0 0.0 7.2
1.0 1.7 0.7 4.6 5.0 0.5 12 0.5 0.4 72
PentaCB-85 PentaCB-87 PentaCB-92 PentaCBs-93/95/98 PentaCB-99 PentaCB-101a PentaCBs-107/108 PentaCB-110 PentaCB-117
0.2 0.7 0.9 0.9 13 2.0 1.0 0.4 0.9
0.2 0.7 0.7 0.8 12 1.6 0.8 0.5 0.8
0.2 0.3 0.6 0.3 6.3 1.2 0.8 0.2 0.4
0.0 0.2 0.1 0.3 4.0 0.4 0.2 0.1 0.2
0.9 1.5 3.5 2.1 28 6.3 4.2 0.9 2.3
0.2 0.7 0.8 0.8 12 1.8 1.0 0.4 1.0
0.2 0.6 0.6 0.7 10 1.4 0.8 0.3 0.7
0.1 0.4 0.7 0.4 7.1 1.3 0.7 0.2 0.8
0.0 0.2 0.2 0.3 2.7 0.3 0.3 0.1 0.2
0.9 2.9 4.8 2.9 40 8.1 5.1 1.0 4.4
HexaCB-128 HexaCB-130 HexaCB-132 HexaCB-134 HexaCB-135 HexaCB-137 HexaCB-138a HexaCB-139 HexaCB-141 HexaCB-146 HexaCB-147 HexaCB-151 HexaCB-153a HexaCBs-163/164
0.9 2.8 0.3 0.0 0.5 3.1 43 0.9 0.4 15 0.5 1.4 97 21
0.8 2.7 0.3 0.0 0.5 2.9 40 0.8 0.3 13 0.5 1.1 85 19
0.5 1.3 0.1 0.0 0.2 1.2 19 0.4 0.2 6.6 0.3 0.8 40 9.3
0.2 0.6 0.1 0.0 0.1 1.3 17 0.2 0.0 5.7 0.1 0.2 42 7.4
2.3 7.8 0.9 0.1 1.1 5.6 85 2.0 1.1 37 1.3 3.5 202 52
0.8 2.5 0.3 0.0 0.5 2.9 39 0.8 0.3 13 0.5 1.2 85 18
0.7 2.1 0.2 0.0 0.4 2.5 35 0.6 0.2 11 0.4 0.8 74 17
0.5 1.7 0.2 0.0 0.3 1.5 20 0.5 0.2 6.7 0.3 1.0 41 9.9
0.1 0.5 0.0 0.0 0.1 0.8 11 0.1 0.1 4.0 0.0 0.2 24 0.0
3.0 11 1.3 0.2 2.3 10 130 3.4 1.2 47 1.9 5.8 270 60
HeptaCB-170 HeptaCB-172 HeptaCB-177 HeptaCB-178 HeptaCB-179 HeptaCB-180a HeptaCB-181 HeptaCBs-182/187 HeptaCB-183 HeptaCB-191
20 3.5 6.5 7.2 0.2 68 0.1 32 6.8 0.9
17 3.0 6.0 6.0 0.2 59 0.1 28 6.5 0.8
9.7 1.7 3.3 3.4 0.1 34 0.0 15 3.1 0.4
8.9 1.5 2.0 3.3 0.0 30 0.0 13 2.4 0.3
66 11 21 22 0.5 235 0.2 90 15 2.2
16 2.6 5.3 5.6 0.2 53 0.1 25 5.7 0.7
13 2.3 4.6 4.7 0.2 46 0.1 22 5.0 0.6
7.7 1.3 2.8 2.8 0.1 26 0.0 13 2.9 0.4
6.1 1.0 1.3 1.9 0.0 20 0.0 8.3 1.7 0.2
52 8.8 18 18 1.1 169 0.3 85 18 2.0
OctaCB-194 OctaCB-195 OctaCBs-196/203 OctaCBs-198/201 OctaCB-200 OctaCB-202 OctaCB-205
11 2.1 9.3 12 0.4 2.3 0.3
9.1 1.9 8.4 10 0.4 2.1 0.3
6.4 1.1 4.8 6.6 0.2 1.5 0.2
4.4 0.9 4.1 5.1 0.0 0.4 0.1
47 7.5 33 47 1.1 9.4 1.0
7.3 1.6 6.8 8.8 0.8 3.2 0.3
6.3 1.4 5.9 7.5 0.3 1.6 0.3
3.6 0.8 3.3 4.5 1.8 5.7 0.1
2.5 0.6 2.7 3.4 0.0 0.0 0.1
23 4.7 22 29 11 40 0.7
NonaCB-206 NonaCB-207 NonaCB-208
2.3 0.4 0.9
2.0 0.4 0.8
1.1 0.2 0.4
1.0 0.2 0.4
7.2 1.0 2.3
1.7 0.3 0.7
1.6 0.3 0.6
0.6 0.1 0.3
0.7 0.1 0.1
4.0 0.8 1.8
DecaCB-209
1.6
1.4
0.6
0.8
3.5
1.2
1.2
0.4
0.4
3.1
Total TriCBs Total TetraCBs Total PentaCBs Total HexaCBs Total HeptaCBs Total OctaCBs Total NonaCBs Total DecaCB Total indicator PCBs Total PCBs
2.6 23 20 187 145 37 3.7 1.6 214 419
2.1 20 18.8 166 126 33 3.4 1.4 189 378
1.5 11 9.2 77 69 20 1.6 0.6 90 180
0.8 5.4 6.0 79 61 16 1.7 0.8 94 172
6.5 52 41 394 464 146 11 3.5 534 1102
2.6 28 19 165 115 29 2.7 1.2 184 363
2.0 25 16 145 98 23 2.5 1.2 160 323
1.8 15 11 81 56 17 1.0 0.4 88 175
1.0 10 5.5 48 41 11 0.9 0.4 58 119
11 98 65 544 372 128 6.6 3.1 591 1226
¡1
Concentration (ng g TriCB-28a TriCB-29
a
lipid)
Indicator PCBs; CB: chlorinated biphenyls; SD: standard deviation.
T. Todaka et al. / Chemosphere 73 (2008) 865–872
The relative contribution ratios of the concentrations of triCBs, tetraCBs, pentaCBs, hexaCBs, heptaCBs, octaCBs, nonaCBs, and decaCB-209 to the total concentrations of 56 non-dioxin-like PCBs congeners for elderly men and women were 0.6%, 5.4%, 4.7%, 44.6%, 34.6%, 8.8%, 0.9%, and 0.4%, respectively, and 0.7%, 7.8%, 5.3%, 45.6%, 31.6%, 7.9%, 0.7%, and 0.3%, respectively, and the ratios were almost the same. Therefore, such characteristics may indicate the existence of the same source of non-dioxin-like PCBs. The sums of the ratios of the concentrations of hexaCBs and heptaCBs to the total concentrations of 56 non-dioxin-like PCBs congeners in the blood of elderly men and elderly women were 79.2% and 77.2%, respectively. The hexaCBs ratios in the blood of elderly men and women were 44.6% and 45.6%, respectively. 2,29,4,49,5,59-HexaCB (#153) among hexaCBs congeners, the most abundant congener in the blood of elderly men and women, contributed approximately 23.0% and 23.5% to the total concen trations of 56 non-dioxin-like PCBs congeners, respectively. Among non-dioxin-like PCBs congeners measured in the present study, 2,29,3,4,49,59-hexaCB (#138), 2,3,39,49,5,6-hexaCB (#163)/ 2,3,39,49,59,6-hexaCB (#164), 2,29,3,4,49,5,59-heptaCB (#180), and 2,29,3,4,49,5,69-heptaCB (#182)/2,29,3,49,5,59,6-heptaCB (#187) also showed high ratios to the total concentrations of 56 nondioxin-like PCBs congeners detected in the blood of elderly men and women. The results obtained in the present study are similar to those by which have been recently reported in Japan (Hirai et al., 2005; Masuda et al., 2005). The total concentrations of these five congeners containing 2,29,4,49,5,59-hexaCB (#153) in elderly men and women contributed approximately 62.4% and 61.0% of the total concentrations of 56 non-dioxin-like PCBs congeners that were measured in the present study, respectively. Other PCBs cong eners contributed less than 5% of the total concentrations of 56 non-dioxin-like PCBs congeners. Some previous studies have attempted to evaluate the levels of dioxin-like PCBs and non-dioxin-like PCBs in human blood. They analyzed only commonly detected PCBs congeners in human blood samples. Therefore, the published data showing the concen trations of full congeners of non-dioxin-like PCBs in human blood are limited. The results obtained by the present study indicate the current levels of non-dioxin-like PCBs in the blood of elderly men and women in Fukuoka Prefecture, Japan and can be used as base line data for those over age 60. To better understand the levels of total non-dioxin-like PCBs in the blood of elderly men and women in Fukuoka Prefecture, Japan, we compared the present data with those from 152 residents (men 75 and women 77; age range 20–60 years) who lived in Fukuoka City in 1999 that had previously been reported in Fukuoka Prefecture, Japan (Masuda et al., 2005). Among 33 non-dioxin-like PCBs cong eners that were measured in the blood of men and women, as pre viously reported, 26 of these congeners (PCB 28, 52/69, 56/60, 66, 74, 99, 101, 130, 137, 138, 146, 153, 163/164, 170, 172, 177, 178, 180, 182/187, 183, 194, 195, 196/203, 198/201, 202, and 206) were com monly detected in the present study. The total concentrations of the 26 congeners measured in the present study contributed approxi mately 96% of the total concentrations of 56 non-dioxin-like PCBs congeners in both elderly men and women. These 26 congeners may therefore be considered to be the most abundant congeners for con gener-specific risk assessment of non-dioxin-like PCBs in humans. Among the 127 elderly residents in the present study, 51 were men (mean: 68.1 years, median: 68.0 years) and 76 were women (mean: 68.1 years, median: 67.0 years). Of the 51 elderly men, 30 were under 69 years old (mean: 64.5 years, median: 64.5 years) and 21 were over 70 years old (mean: 73.2 years, median: 73.0 years). In the case of the 76 elderly women, 46 were under 69 years old (mean: 64.1 years, median: 64.0 years) and 30 were over 70 years old (mean: 74.1 years, median: 73.5 years). The arithmetic mean total concen trations of 26 PCBs congeners in the blood of elderly men (mean:
869
64.5 years) and women (mean: 64.1 years) in the under 69 years group of Nakagawa Town in the present study were lower than those reported from the results in Fukuoka City. The sums of 26 congener concentrations of non-dioxin-like PCBs in the blood of 33 elderly men (mean: 50.5 years, median: 50.1 years) and 23 elderly women (mean: 49.3 years, median: 49.0 years) in the over 40 years group for Fukuoka City were 623.7 and 404.6 ng g¡1 lipid, respec tively, which were 1.6 and 1.3 times higher than the same sums for elderly men and women of Nakagawa Town, respectively. Similar results were observed regarding the levels of indicator PCBs. In a previous study, we measured the concentrations of PCDDs, PCDFs, and dioxin-like PCBs in the blood of 127 elderly residents in a pres ent study. The arithmetic mean total TEQ concentrations of PCDDs, PCDFs, and dioxin-like PCBs in the blood of elderly men (mean: 64.5 years) and women (mean: 64.1 years) in the under 69 years group from Nakagawa Town were 18.7–95.2 (mean: 43.0, median: 37.5) and 18.2–97.5 (mean: 44.7, median: 40.1) pg TEQ g¡1 lipid, respec tively. The concentrations of these dioxin-like compounds in the blood of 33 elderly men (mean: 50.5 years) and 24 elderly women (mean: 49.3 years) in the over 40 years group from Fukuoka City were 10.0–88.7 (mean: 39.0, median: 32.6) and 14.4–102.0 (mean: 42.4, median: 37.5) pg TEQ g¡1 lipid, respectively, which were 0.91 and 0.95 times higher than those of Nakagawa Town, respectively. However, the elderly men and women from Nakagawa Town were on average 15 years older than those from Fukuoka City. When both concentrations were compared in consideration of the age, it seems likely that environmental pollution levels and human exposure to PCDDs, PCDFs, and dioxin-like PCBs in Fukuoka Prefecture have not increased. In the case of the non-dioxin-like PCBs, the levels obtained in the present study show a decrease compared to past lev els in Fukuoka Prefecture reported in 1999. Corresponding results were observed regarding the levels of indicator PCBs. These find ings suggest that more efforts to reduce human exposure to PCDDs, PCDFs, dioxin-like PCBs, and non-dioxin like PCBs in Fukuoka Pre fecture should be continued in future. 3.2. Effects of age on the levels of non-dioxin-like PCBs The total PCBs concentrations in blood samples from the under 69 years group and the over 70 years group for elderly men were 198–756 (mean: 410, median: 358) and 172–1102 (mean: 432, median: 379) ng g¡1 lipid, respectively (Table 2). In the case of elderly women, the concentrations were 119–761 (mean: 328, median: 294) and 200–1226 (mean: 416, median: 345) ng g¡1 lipid, respectively (Table 3). An examination of the results in regard to the relationship between the total concentrations of 56 non-dioxinlike PCBs congeners detected in the blood and the age of elderly men and women confirmed that the levels of those in the over 70 years group were significantly higher than those in the under 69 years group. When the effects of age on the levels of non-dioxinlike PCBs in blood were compared in age-matched groups, the rela tionship between the total concentrations of these PCBs congeners in blood and the age of elderly men and women showed that the levels of these PCBs congeners tend to increase with increases in age in both groups. The concentration ratios of the over 70 years group to the under 69 years group in elderly women are greater than those in elderly men. A statistical examination of the relationship between the total concentrations of 56 non-dioxin-like PCBs congeners detected in blood and the age of elderly residents who were over 60 years indi cated statistically significant correlations between the total con centrations of these PCBs congeners and the age of elderly women (q = 0.299, p = 0.009). However, corresponding correlations were not observed in elderly men (q = ¡0.009, p < 0.951). Moreover, sta tistically significant correlations were observed between the total levels of indicator PCBs in blood and the age of elderly women
870
T. Todaka et al. / Chemosphere 73 (2008) 865–872
Table 2 Concentrations of non-dioxin-like PCBs in the blood of 51 elderly men collected in Nakagawa Town, Fukuoka Prefecture, Japan IUPAC#
Under-69-years old (n = 30)
Over-70-years old (n = 21)
Mean
Median
SD
Min.
Max.
Mean
Median
SD
Min.
Max.
2.4 0.0
2.0 0.0
1.3 0.0
1.0 0.0
6.5 0.1
2.9 0.0
2.1 0.0
1.7 0.0
0.8 0.0
6.0 0.1
TetraCB-44 TetraCBs-47/48 TetraCB-49 TetraCBs-52/69a TetraCBs-56/60 TetraCB-63 TetraCB-66 TetraCB-70 TetraCB-71 TetraCB-74
0.5 0.7 0.3 1.3 0.7 0.1 2.1 0.3 0.2 15
0.5 0.6 0.3 1.3 0.6 0.1 1.6 0.2 0.2 13
0.1 0.2 0.1 0.4 0.5 0.1 1.5 0.1 0.1 8.1
0.2 0.3 0.2 0.7 0.3 0.0 0.7 0.1 0.0 5.0
0.8 1.3 0.5 2.2 2.3 0.4 6.7 0.6 0.3 40
0.4 0.6 0.3 1.4 1.0 0.1 3.0 0.3 0.2 17
0.4 0.6 0.3 1.1 0.8 0.1 2.2 0.2 0.2 16
0.2 0.2 0.1 1.1 0.7 0.1 2.0 0.1 0.1 9.0
0.2 0.2 0.1 0.4 0.2 0.0 0.4 0.1 0.0 3.5
0.8 1.0 0.6 5.8 2.8 0.5 7.1 0.4 0.4 35
PentaCB-85 PentaCB-87 PentaCB-92 PentaCBs-93/95/98 PentaCB-99 PentaCB-101a PentaCBs-107/108 PentaCB-110 PentaCB-117
0.2 0.7 0.8 0.9 13 1.9 0.9 0.5 0.8
0.2 0.7 0.7 0.8 12 1.6 0.7 0.5 0.8
0.1 0.3 0.4 0.3 6.5 0.8 0.7 0.2 0.4
0.1 0.2 0.3 0.6 4.0 0.9 0.3 0.2 0.3
0.5 1.5 1.5 1.5 28 3.7 3.1 0.9 1.7
0.3 0.7 0.9 0.8 12 2.1 1.2 0.4 0.9
0.2 0.6 0.7 0.7 12 1.6 1.0 0.4 0.8
0.2 0.3 0.8 0.4 6.1 1.5 0.9 0.2 0.5
0.0 0.2 0.1 0.3 4.4 0.4 0.2 0.1 0.2
0.9 1.3 3.5 2.1 26 6.3 4.2 0.8 2.3
HexaCB-128 HexaCB-130 HexaCB-132 HexaCB-134 HexaCB-135 HexaCB-137 HexaCB-138a HexaCB-139 HexaCB-141 HexaCB-146 HexaCB-147 HexaCB-151 HexaCB-153a HexaCBs-163/164
0.9 2.7 0.3 0.0 0.5 3.1 43 0.9 0.3 15 0.5 1.4 96 21
0.8 2.9 0.3 0.0 0.5 2.9 42 0.8 0.3 14 0.4 1.2 85 20
0.4 1.1 0.1 0.0 0.2 1.2 19 0.4 0.2 5.7 0.3 0.7 36 8.8
0.3 1.1 0.1 0.0 0.2 1.4 18 0.3 0.1 5.7 0.2 0.5 42 7.4
1.9 5.3 0.6 0.1 1.1 5.6 78 2.0 0.8 29 1.2 2.8 173 46
1.0 2.8 0.3 0.0 0.5 3.1 43 0.8 0.4 15 0.5 1.3 97 21
0.9 2.4 0.3 0.0 0.4 2.9 38 0.6 0.3 13 0.5 1.1 85 19
0.6 1.7 0.2 0.0 0.3 1.3 20 0.5 0.3 7.7 0.3 0.9 45 10
0.2 0.6 0.1 0.0 0.1 1.3 17 0.2 0.0 5.7 0.1 0.2 45 8.1
2.3 7.8 0.9 0.1 1.1 5.6 85 1.8 1.1 37 1.3 3.5 202 52
HeptaCB-170 HeptaCB-172 HeptaCB-177 HeptaCB-178 HeptaCB-179 HeptaCB-180a HeptaCB-181 HeptaCBs-182/187 HeptaCB-183 HeptaCB-191
19 3.3 6.3 7.0 0.2 65 0.1 32 6.8 0.8
18 3.2 6.1 6.2 0.2 60 0.1 29 6.8 0.8
6.6 1.2 2.5 2.5 0.1 23 0.0 12 3.0 0.4
9.5 1.5 2.9 3.3 0.1 31 0.0 14 2.4 0.3
36 6.6 13 13 0.4 132 0.1 60 13 2.2
21 3.6 6.7 7.6 0.2 72 0.1 33 6.8 0.9
16 2.9 5.4 5.7 0.2 55 0.1 28 6.3 0.8
13 2.2 4.2 4.4 0.1 45 0.1 18 3.3 0.4
8.9 1.5 2.0 3.3 0.0 30 0.0 13 2.4 0.5
66 11 21 22 0.5 235 0.2 90 15 2.0
OctaCB-194 OctaCB-195 OctaCBs-196/203 OctaCBs-198/201 OctaCB-200 OctaCB-202 OctaCB-205
9.7 2.1 8.9 11 0.4 2.0 0.3
9.2 1.9 8.6 11 0.4 2.0 0.3
3.2 0.8 3.3 3.8 0.2 0.9 0.1
4.8 0.9 4.6 5.5 0.0 0.4 0.1
18 3.9 17 21 0.7 3.8 0.7
12 2.3 10 13 0.4 2.7 0.3
8.8 1.9 8.1 9.0 0.3 2.1 0.3
9.2 1.5 6.3 9.3 0.3 2.1 0.2
4.4 1.0 4.1 5.1 0.1 0.9 0.2
47 7.5 33 47 1.1 9.4 1.0
NonaCB-206 NonaCB-207 NonaCB-208
2.2 0.4 0.9
2.1 0.4 0.9
0.8 0.2 0.4
1.0 0.2 0.4
4.5 0.8 1.9
2.4 0.4 1.0
1.9 0.4 0.8
1.4 0.2 0.5
1.3 0.2 0.5
7.2 1.0 2.3
DecaCB-209
1.6
1.4
0.5
0.8
2.6
1.6
1.3
0.7
0.8
3.5
Total TriCBs Total TetraCBs Total PentaCBs Total HexaCBs Total HeptaCBs Total OctaCBs Total NonaCBs Total DecaCB Total indicator PCBs Total PCBs
2.4 21 20 186 140 35 3.6 1.6 210 410
2.0 19 19 164 126 33 3.4 1.4 187 358
1.3 9.9 8.6 71 50 12 1.3 0.5 77 149
1.0 8.8 7.4 84 66 18 1.7 0.8 98 198
6.5 52 40 338 275 63 7.0 2.6 388 756
3.0 25 20 188 152 40 3.8 1.6 219 432
2.2 21 19 166 123 30 3.1 1.3 192 379
1.7 12 10 87 90 29 2.0 0.7 109 220
0.8 5.4 6.0 79 61 16 2.0 0.8 94 172
6.1 47 41 394 464 146 10.5 3.5 534 1102
¡1
Concentration (ng g TriCB-28a TriCB-29
a
lipid)
Indicator PCBs; CB: chlorinated biphenyls; SD: standard deviation.
T. Todaka et al. / Chemosphere 73 (2008) 865–872
871
Table 3 Concentrations of non-dioxin-like PCBs in the blood of 76 elderly women collected in Nakagawa Town, Fukuoka Prefecture, Japan IUPAC#
Under-69-years old (n = 46)
Over-70-years old (n = 30)
Mean
Median
SD
Min.
Max.
Mean
Median
SD
Min.
Max.
2.5 0.0
2.0 0.0
1.3 0.0
1.1 0.0
7.8 0.1
2.7 0.0
2.0 0.0
2.3 0.0
1.0 0.0
11 0.1
TetraCB-44 TetraCBs-47/48 TetraCB-49 TetraCBs-52/69a TetraCBs-56/60 TetraCB-63 TetraCB-66 TetraCB-70 TetraCB-71 TetraCB-74
0.4 0.6 0.3 1.1 0.8 0.1 2.1 0.3 0.2 19
0.4 0.5 0.2 0.8 0.7 0.1 1.9 0.3 0.2 18
0.2 0.2 0.1 0.7 0.5 0.1 1.2 0.1 0.1 7.8
0.2 0.3 0.1 0.4 0.2 0.0 0.7 0.0 0.0 7.2
0.8 1.1 0.6 3.4 2.6 0.4 6.6 0.4 0.4 41
0.5 0.6 0.3 1.5 1.0 0.2 2.5 0.3 0.2 27
0.5 0.6 0.3 1.2 0.7 0.1 1.6 0.3 0.2 24
0.2 0.3 0.2 1.0 1.0 0.1 2.5 0.1 0.1 14
0.1 0.3 0.1 0.5 0.3 0.0 0.9 0.1 0.1 9.2
1.0 1.7 0.7 4.6 5.0 0.5 12 0.5 0.3 72
PentaCB-85 PentaCB-87 PentaCB-92 PentaCBs-93/95/98 PentaCB-99 PentaCB-101a PentaCBs-107/108 PentaCB-110 PentaCB-117
0.2 0.6 0.7 0.7 11 1.6 0.9 0.4 0.8
0.2 0.5 0.6 0.6 9.8 1.4 0.8 0.3 0.6
0.1 0.3 0.4 0.3 4.9 0.9 0.5 0.2 0.6
0.0 0.2 0.2 0.3 2.7 0.3 0.3 0.1 0.2
0.6 1.5 2.0 1.7 24 4.7 2.7 0.8 3.5
0.2 0.8 1.1 0.9 15 2.2 1.1 0.4 1.2
0.2 0.7 0.7 0.8 12 1.5 0.8 0.4 0.9
0.2 0.6 1.0 0.6 9.4 1.6 1.0 0.2 1.0
0.1 0.2 0.3 0.3 4.8 0.7 0.3 0.2 0.3
0.9 2.9 4.8 2.9 40 8.1 5.1 1.0 4.4
HexaCB-128 HexaCB-130 HexaCB-132 HexaCB-134 HexaCB-135 HexaCB-137 HexaCB-138a HexaCB-139 HexaCB-141 HexaCB-146 HexaCB-147 HexaCB-151 HexaCB-153a HexaCBs-163/164
0.8 2.2 0.2 0.0 0.4 2.6 36 0.7 0.3 12 0.4 1.0 78 16
0.7 1.8 0.2 0.0 0.4 2.3 31 0.7 0.3 10 0.4 0.8 73 17
0.4 1.3 0.1 0.0 0.2 1.2 15 0.4 0.2 5.0 0.2 0.7 33 8.3
0.1 0.5 0.0 0.0 0.1 0.8 11 0.1 0.1 4.0 0.0 0.2 24 0.0
1.9 7.1 0.6 0.1 1.1 6.6 75 1.9 1.0 29 1.3 3.9 184 46
1.0 3.1 0.3 0.0 0.5 3.3 45 0.9 0.3 15 0.6 1.4 96 20
0.7 2.6 0.2 0.0 0.4 2.7 38 0.6 0.2 13 0.4 0.8 77 17
0.6 2.0 0.2 0.0 0.4 1.9 25 0.7 0.2 8.4 0.4 1.4 50 12
0.4 1.2 0.1 0.0 0.2 1.3 17 0.3 0.1 6.8 0.1 0.3 48 0.0
3.0 11 1.3 0.2 2.3 10 130 3.4 1.2 47 1.9 5.8 270 60
HeptaCB-170 HeptaCB-172 HeptaCB-177 HeptaCB-178 HeptaCB-179 HeptaCB-180a HeptaCB-181 HeptaCBs-182/187 HeptaCB-183 HeptaCB-191
14 2.4 4.6 5.0 0.2 48 0.1 23 5.2 0.7
13 2.2 4.2 4.4 0.2 42 0.1 20 4.6 0.6
6.1 1.0 2.2 2.1 0.1 20 0.0 9.8 2.3 0.3
6.1 1.0 1.3 1.9 0.0 20 0.0 8.3 1.7 0.2
37 6.3 13 12 0.5 117 0.1 55 11 1.9
18 3.0 6.2 6.5 0.2 61 0.1 29 6.5 0.8
16 2.8 5.6 5.6 0.2 55 0.1 23 5.3 0.6
9.5 1.6 3.4 3.4 0.2 32 0.1 16 3.7 0.4
6.4 1.0 2.4 2.5 0.0 22 0.0 12 2.3 0.3
52 8.8 18 18 1.1 169 0.3 85 18 2.0
OctaCB-194 OctaCB-195 OctaCBs-196/203 OctaCBs-198/201 OctaCB-200 OctaCB-202 OctaCB-205
6.6 1.5 6.2 7.9 0.7 3.0 0.3
6.0 1.3 5.2 6.7 0.3 1.3 0.2
2.7 0.6 2.5 3.4 1.6 4.6 0.1
3.2 0.8 2.7 3.4 0.0 0.0 0.1
16 3.8 14 18 11 20 0.6
8.3 1.8 7.7 10 1.1 3.4 0.3
7.8 1.5 6.5 9.1 0.3 1.9 0.3
4.5 0.9 4.2 5.7 2.0 7.0 0.1
2.5 0.6 3.0 3.7 0.0 0.0 0.1
23 4.7 22 29 8.6 40 0.7
NonaCB-206 NonaCB-207 NonaCB-208
1.6 0.3 0.6
1.6 0.3 0.6
0.5 0.1 0.2
0.7 0.1 0.3
3.4 0.6 1.4
1.9 0.3 0.7
1.8 0.3 0.6
0.8 0.2 0.4
0.7 0.1 0.1
4.0 0.8 1.8
DecaCB-209
1.1
1.1
0.3
0.4
2.1
1.3
1.2
0.5
0.7
3.1
Total TriCBs Total TetraCBs Total PentaCBs Total HexaCBs Total HeptaCBs Total OctaCBs Total NonaCBs Total DecaCB Total indicator PCBs Total PCBs
2.5 25 17 151 103 26 2.5 1.1 167 328
2.1 23 15 136 91 20 2.4 1.1 153 294
1.3 10 7.3 63 43 12 0.9 0.3 68 132
1.1 10 5.5 48 41 11 1.1 0.4 58 119
7.8 52 37 354 254 55 5.3 2.1 386 761
2.7 34 22 188 132 33 2.9 1.3 209 416
2.0 30 18 153 113 32 2.7 1.2 173 345
2.3 19 14 99 69 22 1.3 0.5 107 217
1.0 13 8.3 92 51 12 0.9 0.7 102 200
11 98 65 544 372 128 6.6 3.1 591 1226
¡1
Concentration (ng g TriCB-28a TriCB-29
a
lipid)
Indicator PCBs; CB: chlorinated biphenyls; SD: standard deviation.
872
T. Todaka et al. / Chemosphere 73 (2008) 865–872
(q = 0.273, p = 0.017) and similar correlations were not observed in elderly men (q = ¡0.019, p < 0.895). We measured the concentrations of PCDDs, PCDFs, and dioxinlike PCBs in blood collected from 279, 269, 242, and 237 Yusho patients during medical check-ups performed the period from 2002 to 2005, respectively, and in samples from 92, 74, 74, and 114 Yusho-suspected persons during those same years, respectively (Todaka et al., 2005a, 2007a). Based on the results of the followup survey study, the concentration of 2,3,4,7,8-pentachlorinated dibenzofuran, the heat-degraded by-products of PCBs, in the blood officially became part of the diagnostic criteria for Yusho exposure on September 29, 2005 (Todaka et al., 2007b). However, the full con gener-specific concentrations of non-dioxin-like PCBs in the blood of patients have not been analyzed in a survey study for Yusho. In the present study, we conducted congener-specific analysis of nondioxin-like PCBs in the blood of 127 elderly residents unaffected by Yusho living in Fukuoka Prefecture whose ages were similar to those of the Yusho patients. Future study regarding the congener profiles of non-dioxin-like PCBs in the blood of Yusho patients may provide newly important information regarding exposure evalua tion of Yusho patients. We are currently conducting congener-spe cific analysis of non-dioxin-like PCBs in blood collected in 2004 from 242 Yusho patients and 74 Yusho-suspected persons. 4. Conclusions In this study, we performed congener-specific analysis of non-dioxin-like PCBs in blood collected from 127 elderly resi dents in Nakagawa Town of Fukuoka Prefecture, Japan. The pres ent study was one of the few studies where 56 non-dioxin-like PCBs congeners were measured in human blood. The congener pattern of non-dioxin-like PCBs in the present study was similar to that recently reported in Japan. Among non-dioxin-like PCBs congeners measured in the present study, 2,29,4,49,5,59-hex aCB (#153), 2,29,3,4,49,59-hexaCB (#138), 2,3,39,49,5,6-hexaCB (#163)/2,3,39,49,59,6-hexaCB (#164), 2,29,3,4,49,5,59-heptaCB (#180), and 2,29,3,4,49,5,69-heptaCB (#182)/2,29,3,49,5,59,6-hep taCB (#187) showed high ratios to the total concentrations of 56 non-dioxin-like PCBs congeners detected in the blood of elderly men and women. The total concentrations of these five congeners in elderly men and women contributed approximately 62.4% and 61.1% of the total concentrations of 56 non-dioxin-like PCBs cong eners, respectively. A statistical examination of the relationship between the total concentrations of 56 non-dioxin-like PCBs cong eners detected in the blood and the age of elderly residents who were over 60 years indicated statistically significant correlations between the total concentrations of these PCBs congeners and the age of elderly women. However, similar correlations were not observed in elderly men. The contamination of non-dioxin-like PCBs measured in 127 elderly residents has decreased compared to past levels in Fukuoka Prefecture which were surveyed in 1999. The results of the present study indicate the current levels of non-dioxin-like PCBs in the blood of elderly men and women in Fukuoka Prefecture, Japan and can be used as baseline data for those over 60. Furthermore, the data obtained by the present study are necessary for a comparison with the blood levels of the PCBs congeners under consideration between Yusho patients and normal controls for a Yusho study. Acknowledgment This work was supported in part by a Grant-in-Aid for scientific research from the Ministry of Health Labour and Welfare, Japan.
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