Concentrations of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls in blood and breast milk collected from 60 mothers in Sapporo City, Japan

We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho polychlorinated biphenyls (non-ortho PCBs), and mono-ortho polychlorinated biphenyls (mono-ortho PCBs) in paired samples of blood and breast milk collected from 60 mothers in Sapporo City, Hokkaido Prefecture, Japan. The present study is one of the few studies in which PCDDs, PCDFs, and dioxin-like PCBs have been measured in blood and breast milk collected from 60 same mothers. Of these 60 mothers, 30 were primipara (mean: 30.1 years, median: 28.0 years) and 30 were multipara (mean: 32.2 years, median: 32.5 years). The arithmetic mean TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in blood and breast milk of the primiparous mothers were 9.0, 3.3, 5.7, and 0.4 pg TEQ g(-1) lipid, respectively, and 5.2, 2.2, 4.5, and 0.4 pg TEQ g(-1) lipid, respectively, with the total TEQ concentrations of these dioxin-like compounds being 9.3-42.9 (mean: 18.4, median: 17.3) and 7.0-41.1 (mean: 12.3, median: 11.4) pg TEQ g(-1) lipid, respectively. In the case of multiparous mothers, the arithmetic mean TEQ concentrations of these dioxin-like compounds in blood and breast milk were 7.1, 2.7, 5.3, and 0.4 pg TEQ g(-1) lipid, respectively, and 3.9, 1.7, 3.8, and 0.4 pg TEQ g(-1) lipid, respectively, with the total TEQ concentrations being 3.4-28.1 (mean: 15.5, median: 13.9) and 2.7-20.0 (mean: 9.8, median: 9.2)pg TEQ g(-1) lipid, respectively. The total TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in blood and breast milk of primiparous mothers in Sapporo City appeared to be generally lower than those recently surveyed throughout the greater area of Japan. Significant correlations were observed between age and the total TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in the blood of primiparae and multiparae, and significant correlations were also observed between age and the total TEQ concentrations of these dioxin-like compounds in the breast milk of primiparae and multiparae. The total TEQ concentrations of PCDDs, PCDFs, and dioxin-like PCBs in the blood of primiparous mothers showed a close correlation to those in their breast milk and also showed good correlations between the total TEQ concentrations of these dioxin-like compounds in the blood of multiparous mothers and those in their breast milk. The result of a comparison of the arithmetic mean concentrations of each congener of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in blood and breast milk indicated that the transfer of octachlorodibenzo-p-dioxin (OCDD) from the blood to the breast milk was lower than those of other congeners. In contrast, among mono-ortho PCBs congeners, the arithmetic mean concentrations of 2,3',4,4',5-pentachlorobiphenyl (PentaCB) (#118) and 2,3,3',4,4'-PentaCB (#105) in the breast milk were slightly higher than those in the blood, which suggested that breast-fed infants may be at higher risk from mono-ortho PCBs.     

PCDDs, PCDFs, and PCBs concentrations in breast milk from two areas in Korea: body burden of mothers and implications for feeding infants

We determined breast milk concentration of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in 24 mothers living in Korea, and assessed the maternal body burden based on PCDDs/PCDFs and PCBs concentrations in breast milk and an infant intake rate through breast-feeding based on their concentration in breast milk. PCDDs/PCDFs and PCBs levels in breast milk from primipara mothers were found to be higher than those from multipara mothers. For total PCDDs/PCDFs TEQ level, 2,3,4,7,8-PeCDD was the predominant congener, and the proportion of 2,3,7,8-TCDD was less than 3% of total PCDDs/PCDFs TEQ level. For PCBs TEQ level, PCB-126 was the predominant congener. Maternal body burden levels of PCDDs/PCDFs and PCBs based on their concentrations in breast milk were 268-622 TEQ ng. The daily dioxin intakes of mothers were predicted to be 0.78-2.18 TEQ pg/kg/day for PCDDs/PCDFs and 0.34-0.66 TEQ pg/kg/ day for PCBs. For the first year, the body burden of an infant was predicted to be 212 TEQ ng and the daily intake of an infant was predicted to be 85 TEQ pg/kg/day, assuming the mean dioxin-related compounds concentration (27.54 TEQ pg/g fat).     

Concentration changes of PCDDs, PCDFs, and dioxin-like PCBs in human breast milk samples as shown by a follow-up survey

Breast milk is known to discharge dioxins from the human body. However, to date, no direct comparison has been made of the concentrations of dioxin analogues in breast milk obtained from identical population after successive deliveries. We present here follow-up survey results of PCDDs, PCDFs, and dioxin-like PCBs concentrations in human breast milk samples from 35 women living in Tokyo from whom samples had been obtained and analyzed to determine the corresponding concentrations in the past. The average concentrations of total PCDDs, PCDFs, dioxin-like PCBs were 8.5, 5.5, 11 TEQ pg/g fat for the first samples and 5.4, 4.0, 6.6 TEQ pg/g fat for the second samples, respectively. The degrees of reduction of total PCDDs and total dioxin-like PCBs were higher than that of total PCDFs because 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF and 3,3',4,4',5-PeCB (#126), which were the predominant congeners among PCDDs, PCDFs, and dioxin-like PCBs, respectively, had different degrees of reduction. Moreover we observed a significant increase of the concentrations of PCDDs, PCDFs, and dioxin-like PCBs in samples from three women in this follow-up survey, and the patterns of increased isomers differed among the three samples. It was conjectured that the increase of the concentrations was due mainly to dietary intake between deliveries. It is important for pregnant women to have a balanced diet to mitigate the exposure of infants to these chemicals.     

Correlation coefficients between the dioxin levels in mother's milk and the distances to the nearest waste incinerator which was the largest source of dioxins from each mother's place of residence in Tokyo, Japan

BACKGROUND: To observe the relationship between the PCDD/F and Co-PCB levels in samples of human breast milk and nearby waste incinerators in Tokyo, Japan. METHODS: Breast milk was taken from 240 mothers residing in Tokyo, Japan to measure and analyze the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs; 14 congeners), polychlorinated dibenzofurans (PCDFs; 15 congeners), and coplanar polychlorinated biphenyls (Co-PCBs; 12 congeners) contained in the fat. Individual milk samples (about 50 ml) were obtained from the mothers 30 days after delivery, between the months of June and September in 1999 and 2000. A map of Tokyo was used to measure the distances between each mother's place of residence and the closest public and industrial waste incinerators. RESULTS: The distances to the nearest waste incinerators bore no apparent correlations with the congeners of PCDD/Fs and Co-PCBs. The distances were also uncorrelated with the mean toxic equivalent quantities (TEQs) of PCDD/Fs (the sum of PCDDs and PCDFs), Co-PCBs, and the total PCDD/Fs and Co-PCBs. CONCLUSIONS: Although waste incinerators were the largest source of dioxins in Japan at the time of the study, the dioxins levels of mother's milk bore no apparent relationships with the distances between the mothers' domiciles and the nearest waste incinerators. In this study, several meaningful factors were not taken into account, namely, the wind direction, the level of dioxin emitted from each incinerator, the level of environmental pollution of dioxins, and the average time the mothers stayed at home each day. A full understanding of these points awaits future studies.     

Estimation of 1999-2004 dietary daily intake of PCDDs, PCDFs and dioxin-like PCBs by a total diet study in metropolitan Tokyo, Japan

A study of the dietary intake of dioxins, consisting of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dioxin-like PCBs) through foods retailed in the metropolitan Tokyo area from 1999 to 2004 was carried out by the total diet-market basket method on the basis of food classification (14 groups) and the data on food consumption in the Tokyo region obtained from the Japan Nutrition Survey. The daily intake of dioxins per kg of body weight for a 50 kg average adult body was 2.18 pg TEQ/kg/day in 1999, 1.87 pg TEQ/kg/day in 2000, 1.25 pg TEQ/kg/day in 2001, 1.60 pg TEQ/kg/day in 2002 and 2003 and 1.55 pg TEQ/kg/day in 2004, respectively. These amounts were less than the tolerable daily intake (TDI) of 4 pg TEQ/kg/day for dioxins established in Japan. The dioxins taken daily through fish and shellfish (group 10) accounted for more than 50% of sum WHO-TEQs. In addition, more than 90% of the daily intake of dioxins was taken through fish and shellfish (group 10), meat and eggs (group 11), milk and dairy products (group 12). Also, this study clearly showed that the ratio of dioxin-like PCBs in the daily intake of dioxins was increasing yearly because the reduction rate of dioxin-like PCBs was lower than that of PCDDs and PCDFs in foods.     

Concentrations of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and non-ortho and mono-ortho polychlorinated biphenyls in blood of Yusho patients

We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho polychlorinated biphenyls (non-ortho PCBs) and mono-ortho polychlorinated biphenyls (mono-ortho PCBs) in blood collected from 279 Yusho patients living in Japan, 92 Yusho-suspected persons living in Japan and 127 normal controls living in Fukuoka Prefecture, and compared among the groups in terms the concentrations of these compounds. The total toxic equivalents (TEQ) concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in the bloods of Yusho patients and Yusho-suspected persons were 161.4 and 51.2 pg TEQ/g lipid, respectively and were about 3.5 and 1.1 times higher than those of normal controls, respectively. Although the TEQ concentrations of PCDDs, non-ortho PCBs, and mono-ortho PCBs among Yusho patients, Yusho-suspected persons and normal controls were nearly the same, the PCDFs levels of Yusho patients were significantly higher than those of Yusho-suspected persons and about 10.3 times higher than those of normal controls. In Yusho patients, PCDFs contributed about 65% to the total TEQ concentration. Among the PCDFs congeners for Yusho patients, the concentration of 2,3,4,7,8-pentachlorodibenzofuran (PeCDF) was about 11.3 times higher than that of normal controls. These findings indicated that Yusho patients even now, more than 34 years after the outbreak of Yusho, have much higher blood levels of 2,3,4,7,8-PeCDF in general than do unaffected persons.     

Relationship of PCDD/F and Co-PCB concentrations in breast milk with infant birthweights in Tokyo, Japan

OBJECTIVE: To observe how PCDD/F and Co-PCB concentrations in breast milk relate to infant birthweights in Tokyo, Japan. STUDY DESIGN: Breast milk samples were collected from 240 mothers (aged 25-34years old) residing in Tokyo to measure the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs; 14 congeners), polychlorinated dibenzofurans (PCDFs; 15 congeners), and coplanar polychlorinated biphenyls (Co-PCBs; 12 congeners) in the breast milk fat. Individual milk samples (about 50ml) were obtained 30days after delivery, between the months of June and September in 1999 and 2000. The relationship of the infant birthweights with the PCDD/F and Co-PCB concentrations was observed. RESULTS: The birthweights were negatively correlated the concentrations of many of the PCDD/F and Co-PCB congeners, with the mean toxic equivalent quantities (TEQs) of the Co-PCBs, and with the sum of the PCDD, PCDF and Co-PCBs, although their correlation coefficients were less than 0.200. Multiple regression analysis showed octachlorodioxin was statistically significant explanatory variate. CONCLUSIONS: There were slight relationship between the dioxins levels of breast milk and the birthweights of the infants.     

Concentrations of polychlorinated dibenzo-p-dioxins,polychlorinated dibenzofurans,and polychlorinated biphenyls in blood and breast milk collected from pregnant women in Sapporo City,Japan

We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (PCBs), and non-dioxin-like PCBs in paired samples of blood and breast milk collected from 67 secundiparas in Sapporo City, Japan, and combined this data with those of the 30 secundiparas previously measured. The arithmetic mean total toxic equivalents (TEQ-WHO) concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in blood and breast milk of the 97 secundiparous subjects were 3.0–23 (mean: 13, median: 14) and 2.7–20 (mean: 8.6, median: 8.5) pg TEQ g⁻¹ lipid, respectively. The sums of the concentrations of 56 non-dioxin-like PCB congeners that were measured in the subjects’ blood and breast milk were 16–326 (mean: 107, median: 100) and 12–252 (mean: 73, median: 67) ng g⁻¹ lipid, respectively. The partitioning ratios of individual congeners of PCDDs, PCDFs, dioxin-like PCBs, and non-dioxin-like PCBs from blood to breast milk in secundiparas were almost the same as those of primiparas that have been recently reported, suggesting that the partitioning ratios of these compounds from maternal blood to breast milk in women is little affected by delivery. Furthermore, the partition of PCB congeners with chlorine at the 2-, 3-, 4′-, and 5-positions or the 2-, 4-, 4′-, and 5-positions of the biphenyl ring from the blood to the breast milk tended to occur at a higher level than that of other congeners. In particular, the levels of tetraCB-74 and hexaCB-146 in the breast milk for both primiparous and secundiparous mothers were slightly higher than those in the blood.     

Survey of commercial pasteurised cows' milk in Wallonia (Belgium) for the occurrence of polychlorinated dibenzo-p-dioxins,dibenzofurans and coplanar polychlorinated biphenyls

Congener-specific analyses of 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs) and 4 non-ortho (coplanar) polychlorinated biphenyls (cPCBs) were performed on 35 samples of commercial long-life pasteurised cows' milk issued from eight different brands available in Walloon supermarkets (Belgium). The observed congener profile was characteristic of milk samples issued from industrialised countries with good inter and intra-brand reproducibility's. The PCDDs to PCDFs ratio was equal to 1.8 in concentration. The toxic equivalent (TEQ based on WHO-TEF) value for PCDD/Fs in all analysed milks was 1.09+/-0.30 pg TEQ/g fat (range 0.86-1.59), which is below the recommended EU non-commercialisation threshold value of 3 pg TEQ PCDD/Fs/g of milk fat. The mean TEQ value including cPCBs was 2.23+/-0.55 pg TEQ/g fat. These PCBs actually contributed for 49+/-8.6% of the total TEQ. Among PCDD/Fs and cPCBs, tetrachloro dibenzo-p-dioxin (TCDD), pentachloro dibenzo-p-dioxin (PeCDD), pentachloro dibenzofurans (PeCDFs) and 3,3',4,4',5-pentachloro biphenyl (PCB-126) were the most important contributors to the TEQ. Estimated daily intake (EDI) due to consumption of such milks was 0.34 pg TEQ/kg of body weight/day for PCDD/Fs and 0.69 pg TEQ/kg of body weight/day when cPCBs were included.     

Concentrations of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls in blood and breast milk collected from pregnant women in Sapporo City, Japan

We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (PCBs), and non-dioxin-like PCBs in paired samples of blood and breast milk collected from 67 secundiparas in Sapporo City, Japan, and combined this data with those of the 30 secundiparas previously measured. The arithmetic mean total toxic equivalents (TEQ-WHO) concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in blood and breast milk of the 97 secundiparous subjects were 3.0-23 (mean: 13, median: 14) and 2.7-20 (mean: 8.6, median: 8.5) pg TEQ g⁻¹ lipid, respectively. The sums of the concentrations of 56 non-dioxin-like PCB congeners that were measured in the subjects’ blood and breast milk were 16-326 (mean: 107, median: 100) and 12-252 (mean: 73, median: 67) ng g⁻¹ lipid, respectively. The partitioning ratios of individual congeners of PCDDs, PCDFs, dioxin-like PCBs, and non-dioxin-like PCBs from blood to breast milk in secundiparas were almost the same as those of primiparas that have been recently reported, suggesting that the partitioning ratios of these compounds from maternal blood to breast milk in women is little affected by delivery. Furthermore, the partition of PCB congeners with chlorine at the 2-, 3-, 4′-, and 5-positions or the 2-, 4-, 4′-, and 5-positions of the biphenyl ring from the blood to the breast milk tended to occur at a higher level than that of other congeners. In particular, the levels of tetraCB-74 and hexaCB-146 in the breast milk for both primiparous and secundiparous mothers were slightly higher than those in the blood.     

Analysis of polychlorodibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs) in baked-salt food additives in Korea

Thirty-one samples of baked-salt products used in commercial food additives were analyzed for the presence of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Dioxins were highly detected in 12 samples of baked salts. The amount of dioxins found in the samples ranged from 12.47 pg/g to 406.56 pg/g (0.71 pg TEQ/g to 23.51 pg TEQ/g, respectively). The most abundant congeners, as TEQ values, were 2,3,4,7,8-PeCDF; 1,2,3,7,8-PeCDF; and 1,2,3,4,7,8-HxCDF in PCDF congeners and 1,2,3,7,8-PeCDD; 1,2,3,6,7,8-HxCDD; and 1,2,3,7,8,9-HxCDD in PCDD congeners. Meanwhile, PCDDs/PCDFs were analyzed in high-temperature-treated samples of natural sea salt alone and natural sea salt to which di-(2-ethylhexyl)phthalate (DEHP) had been added. In the former case, PCDD/PCDF formation was most evident at temperatures near 450 degrees C, the total amount of dioxins was 90.07 pg/g (6.07 pg TEQ/g), and PCDD congeners comprised less than 50% of the total PCDDs/PCDFs. However, when the latter samples were heated, the total PCDD/PCDF concentration was 512.30 pg/g (21.53 pg TEQ/g), with PCDD congeners comprising over 87% of the total PCDDs/PCDFs.     

PCDDs, PCDFs and dioxin-like PCBs in food of animal origin (Slovakia)

The levels of 17 toxic polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and 12 non-ortho and mono-ortho polychlorinated biphenyls (PCBs) in 73 foodstuff samples of animal origin collected from shops and small farms in selected districts of Slovak Republic are presented in this paper. The concentrations expressed as WHO-TEQ in analysed samples ranged for PCDDs/PCDFs from 0.25 pg/g fat in pork to 75 pg/g fat in cod liver. The TEQ concentrations of non-ortho PCBs were between 0.007 and 181 pg/g fat and mono-ortho PCBs between 0.0083 and 66.5 pg/g fat. The mean concentrations in freshwater fish and imported species of marine fish were 0.089 pg TEQ/g fresh weight for PCDDs/PCDFs, 0.17 pg TEQ/g fresh weight for non-ortho PCBs and 0.034 pg TEQ/g fresh weight for mono-ortho PCBs. The mean total concentration of PCDDs/PCDFs and dioxin-like PCBs in samples of infant milk formula imported from EU countries was 0.98 pg TEQ/g fat.     

Organochlorine compounds,nitro musks and perfluorinated substances in breast milk – Results from Bavarian Monitoring of Breast Milk 2007/8

The aim of the Bavarian Monitoring of Breast Milk (BAMBI) project was to examine 10 organochlorine pesticides (OPs), 3 nitro musks, 6 indicator polychlorinated biphenyls (PCBs), 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), 12 dioxin-like PCBs (dl-PCBs) and several perfluorinated alkyl compounds in breast milk samples. A total of 516 breast milk samples were collected from seven regions in Bavaria and were analyzed by means of GC/ECD, GC/HRMS, and LC/MS-MS.     

Evaluation of dioxin-like chemicals in pooled human milk samples collected in Australia

DESIGN: Human milk samples were collected and analysed for the levels of polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and selected dioxin-like polychlorinated biphenyls (PCBs). In total, 157 individual samples collected during 2002 and 2003 as well as 24 samples collected in 1993 were analysed as 20 pools. RESULTS: PCDDs, PCDFs and dioxin-like PCBs were detected in all pooled samples. For samples collected during 2002/2003, the TEQ(DFP) ranged from 6.0 to 15.2 pg TEQ g(-1) lipid with an average of 9.0 pg TEQ g(-1) lipid. The average lipid content was 3.7+/-0.5%. No systematic differences were observed in the levels of PCDDs, PCDFs and PCBs in human milk samples collected from different regions of Australia during 2002/2003. For samples collected in 1993 and analysed as pools, the mean level, expressed as TEQ(DFP) was 16+/-1.4 pg TEQ g(-1) lipid. The average lipid content was 3.9+/-0.7%. CONCLUSION: The levels of PCDDs, PCDFs and dioxin-like PCBs in the human milk of Australian women are both low compared to international levels and similar across all regions of Australia. Consistent with world-wide trends, the levels of PCDDs, PCDFs and dioxin-like PCBs have decreased over a 10 year period from 1993 to 2003 by approximately 40%.     

Levels and congener profiles of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like polychlorinated biphenyls in cow’s milk collected in Campania, Italy

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and certain dioxin-like polychlorinated biphenyls (dl-PCBs) are a family of chemically-related lipophilic compounds characterized by similar toxicity. Due to their properties they are universally distributed in the environment and classified as persistent organic pollutants (POPs). From most of studies carried out to evaluate human dietary intake, milk and dairy products result as a major contributors of PCDD/Fs uptake. Of course the main source of milk contamination is animal feeds. Lactating ruminants, cows included, transfer these compounds to the food chain by ingestion of contaminated vegetables or soil. Their resistance to degradation and a high lipophilicity means that PCDD/Fs and dl-PCBs may be accumulated into fat tissues from which they are transferred to milk during lactation period.Seventy-nine cows milk samples, collected in the monitoring plan 2008, were analyzed for PCDD/Fs and dl-PCBs. Eleven milk samples were non-compliant corresponding to five breeding livestock located in Caserta province. The distribution of PCDD/Fs and dl-PCBs congeners in these samples was examined in order to determine the likely sources of dioxins. The results show that the congener profile is characterized by a prevalence of PCDFs in respect of PCDDs, that represents the typical pattern of thermal origin contamination.     

PCDD/PCDF, dl-PCB and PBDE serum levels of Slovak general population

Blood serum specimens from 81 non-occupationally exposed adults residing in four areas close to municipal and waste incinerators as well as metallurgical industry plant and 44 adult subjects coming from control area of Slovakia were analysed for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (dl-PCBs) and polybrominated diphenylethers (PBDEs). The concentration of total WHO(98)TEQ PCDD/F/dl-PCBs in whole group of donors from areas where known sources causing dioxin contamination are present was significantly higher than in control group of donors (p<0.001). Correlation between the age of donors and PCDD/F and dl-PCB levels was confirmed (Spearman's r(PCDD/Fs)=0.543, r(dl-PCBs)=0.521, p<0.001). Furthermore, this study presents first results concerning the PBDE congeners in human serum of Slovak general population. The total concentration (congeners 28, 47, 99, 100, 153, 154, 183) in control group was approximately 1.5-times higher in comparison to that of residents coming from areas with supposed environmental pollution. The most abundant congeners in all samples were BDE-47 and BDE-153 with median values of 0.24 ng g(-1) lipid and 0.23ngg(-1) lipid, respectively. The positive association between PBDE values and age of donors was not found.     

Polychlorinated dibenzo-p-dioxins and related compounds in breast milk of Japanese primiparas and multiparas

We analyzed polychlorinated dibenzo-p-dioxins and related compounds in the breast milk of primiparas and multiparas, and estimated the levels transferred to newborns by breast milk in Western Japan. 2,3,7,8-TeCDD equivalents (TEQ) of the chemicals in primiparas decreased slightly from 1994 to 1996. In particular, decreases of the TEQs of total PCDDs and total coplanar PCBs were higher than that of total PCDFs. In 2,3,7,8-TeCDD, 1,2,3,7,8-PeCDD, 1,2,3,6,7,8-HxCDD, 1,2,3,7,8,9-HxCDD, 2,3,4,7,8-PeCDF, 1,2,3,6,7,8-HxCDF, 3,3',4,4',5-PeCB and 3,3',4,4',5,5'-HxCB concentrations, those in the breast milk of multiparas were significantly lower than those in the breast milk of primiparas (p < 0.05, lipid basis). Based on the assumption that newborns ingest 120 g of breast milk per kg body weight per day, the amounts converted to TEQ values were 121 pg/kg/day (primiparas) and 97.2 pg/kg/day (multiparas).     

Apportionment of TEQs from four major dioxin sources in Japan on the basis of five indicative congeners

The major sources of dioxins (polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs)) in the environment in Japan have been considered to be combustion by-products, pentachlorophenol (PCP) formulations, chlornitrofen (CNP, 4-nitrophenyl-2,4,6-trichlorophenyl ether) formulations, and PCB products. Data on PCDDs, PCDFs and DL-PCBs from the four sources were analyzed, and indicative congeners whose concentrations were highly correlated with WHO-2006 toxic equivalencies (TEQs) were identified for each source sample. The indicative congeners for combustion by-products, PCP formulations, and CNP formulations were 2,3,4,7,8-pentachlorodibenzofuran, 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin, and 1,2,3,7,8-pentachlorodibenzo-p-dioxin, respectively; for PCB products, the indicative congeners were IUPAC Nos. #126- and #105-pentachlorobiphenyls. Moreover, using the data on PCDDs, PCDFs and DL-PCBs, we developed a set of equations for estimating the apportionment of TEQs from the four sources by using only the concentrations of the above-mentioned five indicative congeners. The equations were used along with the analysis results of different types of environmental samples collected from Japan, to determine the TEQ contributions of the four sources. The obtained values of TEQ contributions seemed to be reasonable. The estimation method was developed by using the data on major dioxin sources in Japan, and therefore, it is generally adaptable to environmental samples from any part of Japan. The method may be usable for regions outside Japan if source identification is carried out and the estimation equations are modified appropriately.     

Longitudinal increases in PCDD/F and dl-PCB concentrations in human milk in northern China

There is a dearth of information on the temporal changes in polychlorinated dibenzodioxin/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) contamination, in both environmental and biological specimens, in China. We compared the concentrations of PCDD/Fs and dl-PCBs in human milk collected in Shijiazhuang, Hebei Province, in northern China in 2002 (n=30) and 2007 (n=20). The level of PCDD/Fs and dl-PCBs showed an increasing trend. The mean concentrations of PCDD/Fs plus dl-PCBs were 4.47 TEQ pg g(-1) fat and 6.24 TEQ pg g(-1) fat in human milk from Shijiazhuang in 2002 and in 2007, respectively. Based on statistical analysis of questionnaire data collected by in-person interviews with mothers, we found positive correlations between consumption of sea fish and PCDFs. The PCDDs, PCDFs, PCDD/Fs, and PCDD/Fs plus dl-PCBs levels in individuals consuming greater amounts of sea fish were higher than those consuming less sea fish, both with and without adjustments for potential confounding factors. Among 17 congeners of PCDD/Fs, the 2,3,7,8-TCDF, 1,2,3,7,8-PeCDF, 2,3,4,7,8-PeCDF, 1,2,3,4,7,8-HxCDF, 1,2,3,6,7,8-HxCDF, and 2,3,4,6,7,8-HxCDF congener concentrations in 2007 increased 134%, 55%, 53%, 57%, 65% and 130% when compared to 2002 levels, respectively. The 2007 dl-PCB congener levels were greater than those of the 2002 samples, with the exception of PCB81 and PCB77. Specifically, PCB105, PCB114, PCB118, PCB123 and PCB156 had increased greater than twofold from 2002 to 2007. Continuous surveillance of PCDD/F and dl-PCB levels in human milk is needed to accurately evaluate both environmental contamination and the human health risk to neonates in China.     

Concentrations of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls in blood collected from 195 pregnant women in Sapporo City, Japan

We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho coplanar polychlorinated biphenyls (non-ortho PCBs), and mono-ortho coplanar polychlorinated biphenyls (mono-ortho PCBs) in blood collected between 2002 and 2004 from 195 pregnant women living in Sapporo City of Hokkaido Prefecture, Japan. The present study is one of the few studies in which PCDDs, PCDFs, and dioxin-like PCBs have been measured in the blood of pregnant women. Of the 195 pregnant women, 101 were primipara (mean: 28.8 years) and 94 were multipara (mean: 32.4 years). The arithmetic mean total TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs of primiparous and multiparous mothers in Sapporo City were 17.4 (median: 15.7) and 14.0 (median: 13.9)pgTEQ/glipid, respectively, and the concentrations were in the range of 6.6-43.4 and 3.4-28.2pgTEQ/glipid, respectively. In regard to the relationship between the total TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in maternal blood and the number of deliveries or age of primiparous and multiparius mothers, the levels of these dioxin-like compounds tended to decrease with increases in the number of deliveries and significantly increased with increasing maternal age in both groups. Furthermore, significant correlations were observed between the total TEQ concentrations of these dioxin-like compounds and the age of primiparae and multiparae. The total TEQ concentration of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs measured in 195 pregnant women has decreased compared to past levels in Japan for the last several decades. The results of the present study have indicated that dioxin contamination in the blood of young women in Japan is continuing to decrease.