Polychlorinated Biphenyl Concentrations and Estimated Intakes in Fish Oil Supplements on the Japanese Market.

Polychlorinated biphenyls (PCBs) are synthetic organic contaminants that are widespread in the environment. There are 209 PCB congeners. Fish oil produced from marine fish is widely used as a health supplement. PCB contamination of fish oil is of concern. We determined the concentrations of all 209 PCB congeners in commercially available fish oil supplements from Japan and estimated PCB intakes for humans consuming the supplements. We determined the concentrations of non-dioxin-like PCBs separately. The total PCB concentrations in 37 fish oil supplements purchased in Japan were 0.024-19 ng/g whole weight, and the non-dioxin-like PCB concentration range was also 0.024-19 ng/g whole weight. The total PCB intakes calculated for a 50 kg human consuming the supplements were 0.039-51 ng/day (0.00078-1.0 ng/(kg body weight per day)) and the non-dioxin-like PCB intake range was also 0.039-51 ng/day (0.00078-1.0 ng/(kg body weight per day)). The total PCB intakes were much lower than the tolerable daily intake of 20 ng/(kg body weight per day) recommended by the WHO. The results indicated that PCBs in the fish oil supplements pose acceptable risks to humans consuming the fish oil supplements daily.

Association of prenatal exposure to dioxin-like compounds, polychlorinated biphenyl, and methylmercury with event-related brain potentials in school-aged children: The Hokkaido study.

Previous studies have indicated that prenatal exposure to dioxin-like compounds (DLC) or polychlorinated biphenyl (PCB) has a negative association with neurodevelopment in school-aged children. Event-related brain potentials (ERP) can reveal subtle and specific differences in the modulation of cognitive processes that are assumed when they are associated with lower levels of prenatal exposure to DLC or PCBs. This prospective birth cohort study was conducted to examine the association between prenatal exposure to relatively low levels of DLC, PCB or methylmercury (MeHg), and ERP. A total of 55 children who were 13 years old participated in a 3-stimulus oddball task to detect P3a and P3b waves. The task required participants to respond to a target among random stimuli at two difficulty levels. The P3a amplitude reflects an automated attention capture process, and P3b reflects a voluntary attention allocation process. We analyzed DLC congeners in blood samples from four groups, including 7 polychlorinated dibenzo-p-dioxins (PCDD), 10 polychlorinated dibenzofuranes (PCDF), 4 non-ortho PCBs, and 8 mono-ortho PCBs. PCB-153 was chosen as an indicator because of its high correlation with the sum of 58 NDL (non-dioxin-like)-PCBs. MeHg exposure level was assessed by the mercury concentration in hair samples (HHg) taken during the perinatal period. The reaction time to the target stimulus during the oddball task shortened with the increasing MeHg exposure level. Furthermore, P3b latency, which reflect response decision and correlates with reaction time, was also shortened with increasing MeHg level in the difficult condition. These results are counterintuitive because shorter reaction times or rapid decision making reflected by P3 latency are generally favorable. This might be due to nutritional factors such as fatty acids, which have beneficial effects on brain development. The P3a amplitude decreased with non- and mono-ortho PCB and HHg levels, regardless of the difficulty level, and with PCDD, PCDF, and total DLC levels, especially in the difficult condition. P3b latency shortened with HHg, and P3b amplitude decreased with mono-ortho PCBs and PCB-153 in both conditions and with PCDD, PCDF, non-ortho PCBs, and total DLC in the difficult condition. In conclusion, we found an association between prenatal exposure to DLC and a decrease in both P3a and P3b amplitude, even when DLC levels were lower than in most previous studies. Additionally, our results suggest that the automated attention capture process reflected by P3a is associated with maternal MeHg exposure and that the voluntary attention allocation process reflected by P3b is associated with PCB-153. However, these results should be interpreted with caution because of the limitations on sample size, population bias, and statistical analyses.

[Analysis of Tin, Arsenic and Lead in Soft Drinks by Microwave Digestion and Its Applicability].

A microwave digestion method for the analysis of tin, arsenic and lead in soft drinks was studied and its performance was evaluated. The trueness, repeatability (RSD) and Intralaboratory reproducibility (RSD) of the method were estimated to be in the ranges of 93-100, 0.7-6.1 and 0.9-8.6%, respectively. In the preparation of the samples for tin analysis, the addition of sulfuric acid after microwave digestion improved the recovery rate and reproducibility. To verify the applicability of this method, recovery tests were conducted on five types of soft drinks, and the results were satisfactory. It was confirmed that this method is applicable to the digestion of a wide range of soft drinks and to the analysis of tin, arsenic, and lead, and that it reduces working time and makes the work easier compared to the conventional method.

Association of maternal serum concentration of hydroxylated polychlorinated biphenyls with maternal and neonatal thyroid hormones: The Hokkaido birth cohort study.

BACKGROUND: Evidence on the toxicity of hydroxylated metabolites of polychlorinated biphenyls (OH-PCBs) for thyroid hormones (TH) is limited, and the underlying mechanism remains unknown. OBJECTIVES: We aimed to investigate the effects of environmental prenatal exposure to OH-PCBs and maternal and neonatal TH levels, taking the maternal-fetal TH transfer into account. METHODS: In this prospective birth cohort (the "Hokkaido study") we included 222 mother-neonate pairs. We measured five OH-PCB isomers in maternal serum samples either during pregnancy or within 5 days of delivery. Thyroid stimulating hormone (TSH) and free thyroxine (FT4) levels were obtained from maternal blood samples at an early gestational stage (median; 11.1 weeks) and from heel prick samples of neonates between 4 and 7 days after birth. Multiple linear regression analysis and structural equation modeling (SEM) were performed to investigate the associations between maternal OH-PCB and maternal and neonatal TH levels. RESULTS: Median concentration of ∑OH-PCBs was 25.37 pg/g wet weight. The predominant isomer was 4-OH-CB187, followed by 4-OH-CB146+3-OH-CB153. In the fully adjusted linear regression analysis, maternal ∑OH-PCBs was positively associated with maternal FT4, and 4-OH-CB187 was positively associated with both maternal and neonatal FT4 levels. Maternal OH-PCBs showed no significant association with TSH among mothers and neonates. Path analysis indicated the indirect pathway from 4-OH-CB187 exposure to increased neonatal FT4, via maternal THs and neonatal TSH. CONCLUSIONS: These findings suggest that maternal exposure to OH-PCBs during pregnancy may increase both maternal and neonatal FT4 levels. Neonatal FT4 is presumed to be increased by prenatal 4-OH-CB187 indirectly, and this process may be mediated by maternal THs and neonatal TSH.

Sex-related differences in the associations between maternal dioxin-like compounds and reproductive and steroid hormones in cord blood: The Hokkaido study.

BACKGROUND: Prenatal exposure to dioxin-like compounds (DLCs) irreversibly affects fetal reproductive and steroid hormone synthesis. OBJECTIVE: This study aimed to assess the relationships between maternal DLCs and cord blood reproductive and steroid hormones. METHODS: Participants in this study were pregnant women who enrolled in the Sapporo Cohort of the Hokkaido Study between 2002 and 2005. We quantified 29 DLCs during the 2nd and 3rd trimesters in maternal blood. Additionally, we measured the concentrations of progesterone, estradiol (E2), testosterone (T), androstenedione, dehydroepiandrosterone (DHEA), cortisol, cortisone, sex hormone-binding globulin (SHBG), luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, inhibin B, and insulin-like factor-3 (INSL3) in cord blood samples. RESULTS: Data from 183 mother-child pairs were analyzed. We observed sex-dependent associations of DLCs on T/E2 ratios, DHEA, cortisol, cortisone, adrenal androgen/glucocorticoid (AA/GC: sum of DHEA and androstenedione)/(sum of cortisol and cortisone) ratios and SHBG. An increase in maternal DLCs related to decreased T/E2 ratios and SHBG and inhibin B levels, and increased AA/GC ratios and FSH and DHEA levels in male cord blood samples. However, an increase in maternal mono-ortho polychlorinated biphenyls related to increased cortisol, cortisone, and SHBG levels, and decreased DHEA levels and AA/GC ratios in female cord blood samples. CONCLUSIONS: Prenatal exposure to DLCs alters steroidogenesis and suppresses the secretion of inhibin B in male cord blood. Relationships between maternal DLCs and cord blood hormones differ between boys and girls. Further studies are required to clarify whether the effects of in utero exposure to DLCs on adrenal hormones extend into infancy and puberty.

Association of prenatal exposure to PCDD/Fs and PCBs with maternal and infant thyroid hormones: The Hokkaido Study on Environment and Children's Health.

Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) are persistent organic pollutants that are universally detected. Some congeners of PCDDs, PCDFs or PCBs have dioxin-like toxicity, whereas non-dioxin-like PCBs are considered to have different toxicity. Reports of the relationships between prenatal exposure to PCDDs, PCDFs or PCBs and thyroid homeostasis in pregnant women and infants have been inconsistent. The aim of this study was to investigate the effect of maternal serum PCDD/F or PCB levels on maternal and neonatal thyroid hormone (TH) levels in a prospective cohort. Of the 514 subjects in the prospective cohort, 386 mothers and 410 infants were included for analysis. Fifteen dioxins and seventy PCBs in maternal blood collected between 23 and 41weeks of gestation were measured using high-resolution gas chromatography and high-resolution mass spectrometry. Blood samples to measure thyroid stimulating hormone (TSH) and free thyroxine (FT4) levels were obtained from mothers at an early gestational stage (median ten weeks), and from infants between four and seven days of age, respectively. Multiple linear regression analysis was conducted. Median concentration of total PCBs, PCB 153 were 104,700, and 20,500pg/g lipid, respectively. Median total dioxin-TEQ was 13.8pg/g lipid. Total dioxin-TEQ, coplanar PCBs were positively associated with neonatal FT4 (beta=0.224, 0.206, respectively). The association was stronger in boys (beta=0.299, 0.282, respectively). Several PCDD/F and PCB isomers were also positively associated with neonatal FT4. Total PCBs or non-dioxin-like PCBs were not associated with any maternal or neonatal THs. No DLC grouping or congeners were associated with neonatal TSH. Non-ortho PCBs were positively associated with maternal FT4. Three PCB congeners had significant positive association(s) with maternal THs. In conclusion, the results of our study suggest that perinatal exposure to background-level DLCs increases neonatal FT4, especially in boys.

Compound-specific isotopic and congener-specific analyses of polychlorinated biphenyl in the heat medium and rice oil of the Yusho incident.

Compound-specific isotope analysis (CSIA) can be used to examine the source and transformation processes of organic pollutants in the environment. We performed a carbon stable isotope analysis of polychlorinated biphenyl (PCB) congeners in the PCB heat-transfer medium (heat medium) and the original Kanechlor-400 (KC-400, a commercial brand of PCBs) involved in the Yusho incident. The main purpose is to investigate whether isotope fractionation occurred in the rice oil deodorization process that caused the incident. The carbon isotope ratios (δ13C values) of the targeted PCB congeners ranged from - 29.39 to - 27.00‰ in the heat medium and from - 28.77 to - 27.05‰ in the original KC-400. No significant differences were found in the δ13C values, suggesting carbon isotope fractionation did not occur for the targeted PCB congeners in the heat medium when deodorization of rice oil occurred at temperatures above 200 °C. Furthermore, we also conducted a congener-specific analysis of 64 PCB congeners found in the heat medium and rice oil contaminated by it. The total PCB congener concentrations were 503 mg/g in the heat medium and 81 µg/g in the rice oil. The concentrations of the highly chlorinated congeners were significantly lower in the heat medium than in the original KC-400, and the compositional ratios of the lowly chlorinated congeners were relatively lower in the rice oil than in the heat medium. These results suggest that the PCB congener patterns gradually changed from that of the original KC-400 in the deodorization process and subsequent contamination into the rice oil. Thus, a combination of CSIA and congener-specific analysis is a new approach for investigating the changing PCB congener profiles in samples from the Yusho incident.

Prenatal exposure to dioxin-like compounds is associated with decreased cord blood IgE and increased risk of wheezing in children aged up to 7years: The Hokkaido study.

INTRODUCTION: In utero exposure to dioxin-like compounds (DLCs) may cause imbalance of immune development in early infancy. However, there are few epidemiological studies into the effects of in utero exposure to DLCs on allergies and infections during childhood. This study evaluates associations between concentrations of maternal DLCs and cord blood immunoglobulin (Ig) E, as well as allergies and infections during childhood. METHOD: We recruited 514 pregnant women in a maternity hospital in Sapporo, Japan, and measured concentrations of DLCs in 426 maternal blood samples using high-resolution gas chromatography/high-resolution mass spectrometry. We examined the relationship between concentrations of maternal DLCs and cord blood IgE at birth (n=239), as well as for allergies and infections in children at 3.5 (n=327) and 7 (n=264) years, using regression analysis adjusted for confounding variables. RESULTS: We found a positive association between maternal DLC concentrations and frequency of wheezing in children aged up to 7years [odds ratio (OR); 7.81 (95% confidence interval (CI), 1.42 to 42.9)]. At 3.5years, boys showed inverse associations between maternal DLC concentrations and cord blood IgE [partial regression coefficient; -0.87 (95% CI), -1.68 to -0.06], and frequency of wheezing [OR; 0.03 (95% CI), 0.00 to 0.94] but girls did not. DISCUSSION: As one reason for the significant association observed at 7 but absent at 3.5years, we suggest that allergic symptoms are more obvious in older children due to matured immune function. CONCLUSION: The findings suggest that prenatal exposure to DLCs may modify offspring immune responses and result in increased risk of allergy among children of school age.

Effects of low-level prenatal exposure to dioxins on cognitive development in Japanese children at 42months.

BACKGROUND: Prenatal exposure to polychlorinated dibenzo-p-dioxins (PCDDs) or polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dioxin-like compounds [DLCs]) through environmental chemicals may affect the neurodevelopment of children. In our previous study, an inverse association was observed between prenatal DLCs and neurodevelopment of infants aged 6months in both sexes. However, studies are yet to determine how long these adverse effects last. OBJECTIVE: To examine whether the effects of DLCs on cognitive development remains at 42months. METHODS: In this prospective cohort study conducted in Sapporo, Japan, pregnant mothers' blood was analyzed for the congener level of DLCs. The Kaufman Assessment of Battery for Children (K-ABC) was used to test their children's cognitive development at 42months. A total of 141 mother-child pairs were included in the final analysis. The multiple linear regression analysis was used to examine the association between the K-ABC scores and DLC levels in the maternal blood. RESULTS: Seven isomers (1,2,3,6,7,8-HxCDD, 2,3,4,7,8-PeCDF, 33'44'55'-HxCB(#169), 2344'5- PenCB(#114), 233'44'5-HexCB(#156), 233'44'5'-HexCB(#157), 23'44'55'-HexCB(#167), total PCDF, and TEQ-PCDD, PCDF, PCDD/DFs levels were positively associated with the achievement score (AS) of K-ABC. However, total non-ortho PCBs were negatively associated with the Mental Processing Composite Score (MPCS) of K-ABC in males. In females, increased TEQ-dl PCB and TEQ-PCDD/F/dl-PCB were also associated with increasing AS score. CONCLUSIONS: This study suggests that the negative effects of prenatal DLC exposure on children's cognitive development at 6months were not observed in children aged 42months. Regarding the sex-specific effects, AS and DLCs were positively correlated in females, whereas those of MPCS and DLCs were significantly negative in males.

Accumulation properties of polychlorinated biphenyl congeners in Yusho patients and prediction of their cytochrome P450-dependent metabolism by in silico analysis.

In what has become known as the Yusho incident, thousands of people in western Japan were poisoned by the accidental ingestion of rice bran oil contaminated with polychlorinated biphenyls (PCBs) and various dioxins and dioxin-like compounds. In this study, we investigated the accumulation patterns of 69 PCB congeners in the blood of Yusho patients in comparison with those of non-exposed controls. The blood samples were collected at medical check-ups in 2004 and 2005. To compare the patterns of PCB congeners, we calculated the concentration ratio of each congener relative to the 2,2',4,4',5,5'-hexaCB (CB153) concentration. The concentration ratios of tetra- and penta-chlorinated congeners in the blood of Yusho patients were significantly lower than those of controls. To examine the cytochrome P450 (CYP)-dependent metabolic potential of the 2,3',4,4'5-pentaCB (CB118), CB153, and 2,3,3',4,4'5-hexaCB (CB156) congeners, we conducted PCB-CYP (CYP1A1, CYP1A2, CYP2A6, and CYP2B6) docking simulation by in silico analysis. The docking models showed that human CYP1A1, CYP2A6, and CYP2B6 isozymes have the potential to metabolize CB118 and CB153. On the other hand, it was inferred that CB156 is difficult to be metabolized by these four CYP isozymes. These results indicate that CYP1 and CYP2 isozymes may be involved in the characteristic accumulation patterns of PCB congeners in the blood of Yusho patients.

Gender-specific association of exposure to non-dioxin-like polychlorinated biphenyls during pregnancy with methylation levels of H19 and long interspersed nuclear element-1 in cord blood in the Hokkaido study.

BACKGROUND: Associations between prenatal exposure to polychlorinated biphenyls (PCBs) and reduced birth-size, and between DNA methylation of insulin-like growth factor-2 (IGF-2), H19 locus, and long interspersed nuclear element-1 (LINE-1) and reduced birth-size are well established. To date, however, studies on the associations between prenatal exposure to PCBs and alterations in methylation of IGF-2, H19, and LINE-1 are lacking. Thus, in this study, we examined these associations with infant-gender stratification. METHODS: We performed a prospective birth cohort study using the Sapporo cohort from the previously described Hokkaido Birth Cohort Study on Environment and Children's Health conducted between 2002 and 2005 in Japan. In the final 169 study participants included in this study, we measured the concentrations of various non-dioxin-like PCBs in maternal blood during pregnancy using high-resolution gas chromatography/high-resolution mass spectrometry. IGF-2, H19 and LINE-1 methylation levels in cord blood were measured using the bisulfite pyrosequencing methods Finally, we assessed the associations between prenatal exposure to various PCBs and the gene methylation levels using multiple regression models stratified by infant gender. RESULTS: We observed a 0.017 (95% confidence interval [CI]: 0.003-0.031) increase in the log10-transformed H19 methylation levels (%) in cord blood for each ten-fold increase in the levels of decachlorinated biphenyls (decaCBs) in maternal blood among all infants. Similarly, a 0.005 (95% CI: 0.000-0.010) increase in the log10-transformed LINE-1 methylation levels (%) in cord blood was associated with each ten-fold increase in heptachlorinated biphenyls (heptaCBs) in maternal blood among all infants. In particular, we observed a dose-dependent association of the decaCB levels in maternal blood with the H19 methylation levels among female infants (P value for trend=0.040); likewise a dose-dependent association of heptaCB levels was observed with LINE-1 methylation levels among female infants (P value for trend=0.015). Moreover, these associations were only observed among infants of primiparous women. CONCLUSION: Our results suggest that the dose-dependent association between prenatal exposure to specific non-dioxin-like PCBs and increases in the H19 and LINE-1 methylation levels in cord blood might be more predominant in females than in males.

The Vernix Caseosa is the Main Site of Dioxin Excretion in the Human Foetus.

Dioxins are highly toxic to foetuses and prenatal exposure leads to adverse health effects; however, the metabolic pathways involved in dioxin excretion are poorly understood. We determined the dynamics of maternal-to-foetal dioxin transfer during normal pregnancy and how foetuses eliminate polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and non-ortho polychlorinated biphenyls. Dioxin levels in maternal blood, cord blood, placenta, vernix caseosa, meconium, and amniotic fluid were analysed by high-resolution gas chromatography/mass spectrometry. The average levels of total dioxins, expressed as picograms of toxic equivalency quantity per gram of lipid and in parentheses, dioxin fraction, with maternal blood levels arbitrarily set as 100%, were as follows: maternal blood, 15.8 (100%); placenta, 12.9 (81.5%); cord blood, 5.9 (37.2%); vernix caseosa, 8.4 (53.2%); meconium, 2.9 (18.2%); and amniotic fluid, 1.5 (9.2%). Similar proportions were observed for each dioxin congener. Thus, the highest content of foetal dioxins was observed in the vernix caseosa, indicating that this is the major site of dioxin excretion in human foetuses.

[The Distribution of Dioxin Concentrations in the Blood of Yusho Patients].

In 1968, the contamination of cooking oil by heat-degraded polychlorinated biphenyls (PCBs) caused a case of mass poisoning, the so-called Yusho incident. The cause of Yusho disease is thought to be ingested toxic substances, including not only PCBs but also polychlorinated dibenzofuran (PCDFs) in Kanemi rice oil. We previously measured dioxins concentrations in the blood of 854 Yusho patients by annual medical examination from 2001 to 2013. We determined the concentrations of 2,3,4,7,8-PeCDF, 1,2,3,4,7,8-HxCDF, 1,2,3,6,7,8-HxCDF and 3,3',4,4',5,5'-HxCB (#169) in the blood of Yusho patients were more than double those of normal controls. In 2012, a new Yusho criteria was established. Family members living with a Yusho patient were also certified as Yusho patients and called Yusho family cohabitant patients. In this study, we compared the distribution of 2,3,4,7,8-PeCDF concentration in the blood of Yusho patients and Yusho family cohabitant patients. It was suspected that the distribution of 2,3,4,7,8-PeCDF concentration in Yusho family cohabitant patients would be lower than that of Yusho patients.

[Blood PCB Concentrations and their Tendencies Examined in Fukuoka 2011-2014 Annual Inspections for Yusho].

We measured PCBs of blood of 154 people in the Yusho medical check-up from January 2011 through December 2014 and analyzed their PCB blood patterns. Eleven examinees were newly certified as Yusho patients during these 4 years. Of these 11, we identified three Yusho patients with the A pattern, five with the B pattern, and three with the BC pattern. We found no Yusho patients with the C pattern. The B pattern was found in 27 of the 154 examinees, such that the probability that an examinee with the B pattern would be certified as a Yusho patient was about 20%. Since 2012, any family members living with a Yusho patient have also been certified as Yusho patients. The number of such family cohabitants was 16, among whom the PCB pattern was uniformly the C pattern. There were 20 examinees born after 1989, and all those examinees were Yusho-suspected persons. The total PCB concentrations of this younger-age group was less than 0.5 ng/g on average and was low compared with the normal controls.

A Study on Polychlorinated Biphenyls Specifically--Accumulated in Blood of Yusho Patients Collected from Medical Check-Ups in 2012.

In this study, we analyzed polychlorinated biphenyls (PCBs) in the blood of Yusho patients collected from medical check-ups, which were conducted in 2012. The results show that 65 PCB isomers, not including non-ortho PCBs, were detected in the blood samples, and the total concentration was 620 ng g(-1) lipid. This value was comparable to the concentration in blood samples collected in 2005, and indicated that PCB concentrations in Yusho patients remained unchanged from 2005 to 2012. Here, we focused on major and specific PCB isomers in the blood samples of Yusho patients and normal controls. Examples of the former include hexaCB-153, hexaCB-138, and heptaCB-180, which are detected in human blood, while the latter include hexaCB-156, hexaCB-157, and heptaCB-189, and are highly detected in the blood of Yusho patients. Additionally, we tried to determine why the specific isomers were highly accumulated in the blood of Yusho patients as compared to the normal controls. We therefore analyzed these isomers in the contaminated rice oil, and found that the concentrations of hexaCB-156, hexaCB-157, and heptaCB-189 were 1800, 450, and 190 ng g(-1), respectively. Notably, previous studies indicated that these isomers might not be easily metabolized in humans. Therefore, these findings demonstrated that these isomers were highly accumulated in the blood of Yusho patients.

[Inter-laboratory crosscheck study of dioxins and PCBs in human blood samples].

We developed an analytical method for accurately determining the concentrations of dioxin and polychlorinated biphenyls(PCBs) in a blood volume of 5 g. Inter-laboratory crosscheck is available for maintaining the quality of dioxin and PCB analysis. We carried out the crosschecks of dioxin and PCB analysis in the blood with domestic analysis organizations. Two crosschecks each of dioxin and PCB analysis were carried out from 2007 through 2011. As a result, the findings of our analysis accorded well with the analyses of the other organizations. We believe that our analytical method is sufficiently reliable.

Improvement of measurement method for hydroxylated polychlorinated biphenyls (OH-PCBs) in blood samples using LC/MS/MS.

Hydroxylated polychlorinated biphenyls (OH-PCBs) are well known as metabolites of PCBs in the human body. We improved a measurement method for OH-PCBs in blood samples using LC/MS/MS. A new 2 microm particle column was used, and the analytical conditions for the LC/MS/MS measurements were optimized. The improved method is more sensitive than the conventional method for 5g blood samples. And, this method is effective at determining the concentrations of OH-PCBs, PCBs and dioxins from the same sample without special treatment of the sample such as derivatization.

Concentration of hydroxylated polychlorinated biphenyls (OH-PCBs) in the blood of Yusho patients in 2010.

Hydroxylated polychlorinated biphenyls (OH-PCBs) are formed as major metabolites of PCBs by cytochrome P450 enzyme-mediated oxidation. It has been reported that their total concentration in serum samples of Yusho patients ranged from 390 to 1300 pg/g. We measured the concentration of OH-PCBs in blood collected from 183 Yusho patients living in Japan in 2010. The major OH-PCB metabolites were 4-OH-CB187 (ND-1300 pg/g-wet), 4-OH-CB146 + 3-OH-CB153 (8.4-1200 pg/g-wet), 4-OH-CB109 (ND-530 pg/g-wet) and 4'-OH-CB172 (ND-380 pg/g-wet). The total OH-PCBs ranged from 36 to 3800 pg/g-wet. A positive relationship between the concentrations of OH-PCBs and PCBs was observed, but no significant relationship between the concentrations of OH-PCBs and PCDD/DFs was observed.

[Examination of alkali digestion temperature in isomer specific analysis of PCB in whole blood sample].

We compared concentrations of PCB congeners between conventional 80 degrees C alkali digestion method and 30 degrees C alkali digestion method using 22 individual blood samples collected during 2009 annual Yusho examinations. The mean concentration of tri-CB in 30 degrees C alkali digestion method was lower than that of conventional method. However, concentration of total PCBs, 2,3',4,4',5-pentaCB (PCB118), 2,2',4,4',5,5'-hexaCB (PCB153) and 2,3,3',4,4', 5-hexaCB (PCB156), which were used as index for Yusho diagnosis, were equivalent between the methods. It was considered that the 30 degrees C alkali digestion method was available for blood PCB congener specific analysis in Yusho diagnosis.

Characterization of placental transfer of polychlorinated dibenzo-p-dioxins, dibenzofurans and polychlorinated biphenyls in normal pregnancy.

AIM: Prenatal exposure to dioxins may result in many adverse health effects. However, the mechanisms by which dioxins are transferred from mother to fetus through the placenta are not well understood. The aim of this study was to investigate the differences in dioxin concentrations between maternal blood, the placenta, and cord blood in normal pregnant women, and to identify which individual congeners of these compounds are transferred from mother to fetus through the placenta. MATERIAL AND METHODS: Samples were collected from 19 pregnant Japanese women. Specific congeners of seven polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), and four non-ortho polychlorinated biphenyls (PCBs) were analyzed. RESULTS: The TEQ concentrations of PCDDs, PCDFs, and non-ortho PCBs were 8.03, 3.39, and 3.95 pg TEQ/g lipid, respectively, in the maternal blood; 8.78, 3.61, and 0.87 pg TEQ/g lipid in the placenta; and 4.33, 1.25, 1.08 pg TEQ/g lipid in the cord blood. Among specific congeners, 1,2,3,7,8-PentaCDD and 2,3,4,7,8-PentaCDF exhibited a placenta to maternal blood ratio greater than 1.0, while OctaCDD exhibited the greatest cord blood to placenta ratio. The cord blood to maternal blood ratio of total PCDDs was significantly higher than that of total PCDFs and total non-ortho PCBs. CONCLUSION: The dioxin concentration in cord blood was approximately half of the amount in maternal blood, despite congeners showing a high toxic equivalency factor accumulating in the placenta. PCDDs were transferred more readily than PCDFs and non-ortho PCBs from maternal blood to the fetus through the placenta.