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European Biota Quality Standards (EQS biota ), for compounds with low water solubility and high biomagnification, were created to sustain water quality and protect top predators and humans from secondary poisoning. In reality, for multiple compounds, an exceedance of these standards is often reported in literature without a decrease in ecological water quality determined by biotic indices. In the present study, threshold concentrations were defined in biota (from 44 sampling locations throughout Flanders (Belgium)), above which a good ecological water quality, assessed by the Multimetric Macroinvertebrate Index Flanders (MMIF), was never reached. Threshold values were compared to current EQS biota . Accumulated perfluoroctane sulfonate (PFOS), mercury (Hg), hexabromocyclododecane (HBCD), polybrominated diphenyl ethers (PBDEs), dioxins and polychlorinated biphenyls (PCBs) concentrations were measured in muscle tissue of European yellow eel (Anguilla anguilla) and perch (Perca fluviatilis). Fluoranthene and benzo(a)pyrene were also analyzed in translocated mussels (Dreissena bugensis, D. polymorpha and Corbicula fluminea). Threshold values could only be calculated using a 90th quantile regression model for PFOS (in perch; 12 µg/kg ww), PCBs (in eel; 328 µg/kg ww) and benzo(a)pyrene (in mussels: 4.35 µg/kg ww). The lack of a significant regression model for the other compounds indicated an effective threshold value higher than the concentrations measured in the present study. Alternatively, the 95th percentile of concentrations measured in locations with a good ecological quality (MMIF≥0.7), was calculated for all compounds as an additional threshold value. Finally, fish concentrations were standardized for 5% lipid content (or 26% dry weight content for PFOS and Hg). Threshold values for PFOS and benzo(a)pyrene and the 95th percentiles for dioxins and fluoranthene were comparable to the existing standards. For all other compounds, the 95th percentile was higher than the current EQS biota , while for HBCD, it was lower. These results strongly advise revising and fine-tuning the current EQS biota , especially for ∑PBDE and HBCD., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Detailed polychlorinated biphenyl (PCB) signatures and chiral Enantiomer Fractions (EFs) of CB-95, CB-136 and CB-149 were measured for 30 workers at a transformer dismantling plant. This was undertaken to identify sources of exposure and investigate changes to the PCB signature and EFs over different exposure periods. Approximately 1.5 g of serum was extracted and PCB signatures were created through analysis by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) and EFs calculated following analysis by gas chromatography with high resolution mass spectrometry (GC-HRMS). A total of 84 PCBs were identified in the serum samples with concentrations of the 7 indicator PCBs ranging from 11-350 ng g(-1) of serum (1.2-39 μg g(-1) lipid). The PCB signatures were interpreted using principal component analysis (PCA) which was able to distinguish workers with background or recent minimal exposure from those with prolonged occupational exposure. Occupationally exposed individuals had a similar PCB profile to Aroclor A1260. However, individuals with prolonged exposure had depleted proportions of several PCB congeners that are susceptible to metabolism (CB-95, CB-101 and CB-151) and elevated proportions of PCBs that are resistant to metabolism (CB-74, CB-153, CB-138 and CB-180). The results also identified a third group of workers with elevated proportions of CB-28, CB-60, CB-66, CB-74, CB-105 and CB-118 who appeared to have been exposed to an additional source of PCBs. The results show near complete removal of the CB-95 E2 enantiomer in some samples, indicating that bioselective metabolism or preferential excretion of one enantiomer occurs in humans. By considering PCB concentrations along with detailed congener specific signatures it was possible to identify different exposure sources, and gain an insight into both the magnitude and duration of exposure., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The European Regulations laying down methods of sampling and analysis for the EU official control of levels of polychlorodibenzo-p-dioxins (PCDDs), polychloro-dibenzofurans (PCDFs), dioxin-like (DL) and non dioxin-like (NDL) PCBs in food and feed have been recently amended by EU Regulation Nos. 589/2014 and 709/2014. A major update is the recognition of gas chromatography (GC) triple quadrupole mass spectrometry (GC-QQQMS/MS) as a confirmatory tool for checking compliance with maximum levels (ML). These revisions have been initiated since this technology now exhibits similar performances to GC (magnetic sector) high resolution mass spectrometry (GC-HRMS). In this paper, we show a fully validated method for PCDD/Fs and DL-PCBs analysis in feed material of plant origin (vegetable oil) using GC-QQQMS/MS following the dedicated EU Regulation 709/2014. We show that individual analytical criteria (selectivity, linearity, quant/qual MRM transitions, accuracy around ML of 1.50ng WHO2005TEQ/kg, within-lab reproducibility, robustness, and background subtraction) meet the strict requirements set by the EU Regulation. We also propose a clear interpretation of instrumental limit of quantitation (iLOQ) as a 'performance-LOQ', defined in a specific way for GC-QQQMS/MS, and method limit of quantitation (mLOQ) as 'real-LOQ' that is used to report bound results. Eventually, the evaluation of measurement uncertainty, following a top-down approach and data produced with our method, demonstrates similar results than with GC-HRMS, thus offering a reliable alternative to the standard method for vegetable oil., (Copyright © 2014 Elsevier B.V. All rights reserved.)

In South Africa, 26-50% of households use solid fuel for cooking food and heating houses. When used as fuel, wood and chlorinated waste are known sources of polychlorinated dibenzo-para-dioxins, polychlorinated dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs). Here, we compare PCDD/F, dioxin-like PCB (DL-PCB), and non-DL-PCB (NDL-PCB) levels in serum of 693 Tswana individuals in the North West province, who either burn solid biofuels or have access to electricity, gas, and paraffin. This is the first South African study on dioxin levels in humans with more than 100 participants. Serum was pooled according to fuel use, as well as to confounding factors such as gender and age. Solid-phase extraction was used to remove the target analytes from serum, after which the extracts were further refined automatically using a combination of multilayer sorbents. Compound concentrations were determined by high-resolution mass spectrometry after high-resolution gas chromatography. Mean serum lipid content was determined enzymatically to be 5.91 ± 0.42 g/L. The PCDD/F and DL-PCB levels were similar to global concentrations reported for non-exposed adults. The mean of the total Toxic Equivalencies (ΣTEQ) was 6.9 ± 3.3 pg/g lipid and the mean NDL-PCB was 70.1 ± 42.8 ng/g lipid. The mean concentrations of the PCDDs, PCDFs and the corresponding World Health Organization-TEQ (WHO-TEQ) of the population using electricity, gas, and paraffin were greater than of those reliant on solid biomass (p = 0), whereas the DL-PCBs, their corresponding WHO-TEQ, and NDL-PCBs were greater for the population who use biofuels but not significantly so. The females had higher serum levels of the PCDDs (p = 0) and PCDFs (not significant) whereas the PCBs were higher for the males (p = 0). Breastfeeding women presented lower levels of all compound classes than their non-breastfeeding counterparts (p=0) and older subjects manifested greater pollutant loads than the younger generation (p = 0). For our study population, being regularly exposed to the combustion of solid biofuels caused higher serum levels of DL-PCBs and NDL-PCBs but not of PCDDs and PCDFs., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

We report on the pilot study carried out before the start of the Elfe project (French longitudinal study from childhood). A total of 44 samples of mature human milk were collected at home 8 weeks after delivery. A total of 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), 12 dioxin-like (DL) polychlorinated biphenyls (PCBs), and 6 non dioxin-like (NDL)-PCBs were measured. For total TEQ (PCDD/Fs and DL-PCBs), the geometric mean concentration was 17.81 pg TEQ(WHO05)/g lipids. Relative PCDD, PCDF, and DL-PCB contributions to the arithmetic mean TEQ(WHO05) were 38%, 18%, and 44%, respectively. The use of TEF(WHO05) instead of TEF(WHO98) resulted in a 27% reduction of the total TEQ value. Although PCDD levels did not significantly change (less than 0.5% increase), PCDF and DL-PCB levels both decreased by 35% and 38%, respectively. Levels have been compared to data obtained during a previous non-reported national study conducted in 1998 (TEF(WHO98)) in French lactaria (n=244). The mean of PCDD/Fs has decreased about 39.4% (18.8 pg TEQ(WHO98)/g lipids in 1998 vs 11.4 pg TEQ(WHO98)/g lipids in pilot study), respectively 41.5% for PCDDs (10.6 pg TEQ(WHO98)/g lipids in 1998 vs 6.2 pg TEQ(WHO98)/g lipids in pilot study) and 36.7% for PCDFs (7.9 pg TEQ(WHO98)/g lipids in 1998 vs 5.0 pg TEQ(WHO98)/g lipids in pilot study). For the sum of the 6 NDL-PCBs, the 2007 geometric mean concentration in milk was 176.3 ng/g lipids. The arithmetic mean lipid concentration in 2007 breast milk was 26.4 g/l (range from 6.0 to 46.7 g/l). A PCDD/F and DL-PCB daily intake was estimated to be 62.3 pg TEQ(WHO05)/kg body weight per day (85.0 pg TEQ(WHO98)/kg body weight per day) for a baby of 5 kg of body weight fed daily with 700 ml of maternal milk containing 25 g/l of lipids., (Copyright © 2013 Elsevier B.V. All rights reserved.)

To date, despite the fact it represents a very important part of the national dairy production, no data are available concerning the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) in camel milk from the Republic of Kazakhstan. Selected PCDDs, PCDFs, and PCBs were measured in pools of milk from camels (n=15) located in various places of Kazakhstan (Almaty, Atyrau, Aralsk, Shymkent) and sampled at two different seasons for two different species (Camelus bactrianus and Camelus dromedarius). Non-dioxin-like (NDL-)PCB concentrations (6.3±2.7 ng g(-1) fat, median 5.1 ng g(-1) fat, range 0.6-17.4 ng g(-1) fat) were far below the maximum value of 40 ng g(-1) fat proposed by the EU. Dioxin-like (DL-)PCB concentrations (1.7±0.7 ng g(-1) fat, median 1.5 ng g(-1) fat, range 0.3-4.2 ng g(-1) fat) and the NDL-PCB to DL-PCB ratio (4.3) were similar to what is reported in EU for cow-based dairy products. PCB 52 and PCB 101 appeared to be proportionally more present in Kazakh camel milk samples (>60% of the sum of the 6 indicator NDL-PCBs) than in European cow milk samples (<10% of the sum of the 6 indicator NDL-PCBs), indicating possible differences in the route of exposure to PCBs in Kazakhstan. PCB 105 and PCB 118 appeared to be present at higher concentrations in camel milk (>80% of the sum of the 12 DL-PCBs). PCB 105, PCB 118 and PCB 156 were the major congeners for DL-PCBs, accounting for 92% of the sum of concentrations of DL-PCBs (88% for Belgian cows). In terms of TEQ, PCB 126 and PCB 118 are the major contributors and represent, respectively, 80% and 14% of the DL-PCB TEQWHO05 concentrations. No significant interracial or geographical trends were observed for NDL- and DL-PCB profiles. However, concentrations of all DL-PCBs appeared to be significantly higher for samples collected in Atyrau region. 2,3,7,8-TCDD level (mean 0.08±0.07 pg g(-1) fat, median 0.08 pg g(-1) fat, range 0.00-0.18 pg g(-1) fat, 60%>LOQs) were very low for all samples and 2,3,4,7,8-PeCDF was the major contributor (27%) to the PCDD/F TEQWHO05. Considering the total TEQWHO05 (sum of DL-PCBs and PCDD/Fs), DL-PCB and PCDD/F contributed for 73% and 27%, respectively. A decrease of only 1% of the total TEQ was observed when using the TEFWHO05 scale instead of the TEFWHO98 scale. Two samples collected in the region of Atyrau exceeded the EU maximum level value of 6.00 pg TEQWHO98 g(-1) fat (6.4 pg TEQWHO05 g(-1) fat and 6.9 pg TEQWHO05 g(-1) fat). Both samples exceeded the EU action level for the sum of DL-PCBs. Based on the fact that camel milk is used to prepare popular traditional fermented drinks like shubat, this suggests that the human exposure in the Caspian Sea region of Atyrau should be expected to be higher than in the other regions studied here., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Dioxins, furans and dioxin-like polychlorinated biphenyls (PCBs) were analysed in muscle tissue from yellow phased European eel (Anguilla anguilla) from 38 sites in Belgium. Dioxin concentrations in eel vary considerably between sampling locations, indicating that yellow eel is a good indicator of local pollution levels. Measured levels of dioxin-like PCBs are much higher than those of the dioxins and furans. In the majority of the sites, eel has levels considered to be detrimental for their reproduction. Field levels of dioxin and dioxin-like PCBs are therefore suggested as an additional causal factor contributing to the decline of the European eel. 42% of the sampling sites show especially dioxin-like PCB levels exceeding the European consumption level (with a factor 3 on average). Human consumption of eel, especially in these highly contaminated sites, seems unjustified., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The World Health Organization recommends assessing human exposure to contaminants on a regular basis. In order to assess the current dietary exposure of the Belgian adult population to PCDD/Fs and dioxin-like PCBs and to update exposure estimates of 2000-2001, a total diet study was designed. The mean dietary intake of PCDD/Fs and dioxin-like PCBs in the Belgian adult population in 2008 was estimated to be 0.72pgTEQkgbw(-1)d(-1) (middle bound concentrations, TEF of 1998) based on occurrence data of 2008 and national food consumption data of 2004. This value is clearly below the Tolerable Weekly Intake (TWI) of 14pgTEQkgbw(-1)week(-1) set by the Scientific Committee on Food of the European Commission and below the provisional tolerable monthly intake of 70pgTEQkgbw(-1)month(-1) set by the Joint FAO/WHO Expert Committee on Food Additives. Considering the cumulative distribution, the intake was less than 1pgTEQkgbw(-1)d(-1) for more than 80% of the population, and less than 2pgTEQkgbw(-1)d(-1) for the entire population. When using the 2005 TEF instead of the 1998 TEF, the mean dietary intake in the Belgian adult population was estimated to be 0.61pgTEQkgbw(-1)d(-1)., (2010 Elsevier Ltd. All rights reserved.)

We evaluated the impact of two iron and steel plants and two municipal solid waste incinerators (MSWI) in Wallonia (Belgium) on the exposure of residents to dioxins, polychlorinated biphenyls (PCBs), and heavy metals. In total, 142 volunteers living around these facilities were recruited and compared with 63 referents from a rural area with no industrial source of pollution. Information about smoking habits, dietary habits, anthropometric characteristics, residential history, and health status was obtained from a self-administered questionnaire. The volunteers provided blood under fasting conditions in order to evaluate the body burden of dioxins (17 polychlorinated dibenzo-p-dioxins/dibenzofurans [PCDD/Fs] congeners) and PCBs. Samples of blood and urine were also taken for the determination of cadmium, mercury, and lead. After adjustment for covariates, concentrations of cadmium, mercury, and lead in urine or blood were not increased in subjects living in the vicinity of MSWIs or sinter plants by comparison with referents. Residents around the sinter plants and the MSWI located in the industrial area had concentrations of dioxins and PCBs in serum similar to that of referents. By contrast, subjects living in the vicinity of the MSWI in the rural area showed significantly higher serum levels of dioxins (geometric mean, 38 vs. 24 pg TEQ/g fat) and coplanar PCBs (geometric mean, 10.8 vs. 7.0 pg TEQ/g fat). Although age-adjusted dioxin levels in referents did not vary with local animal fat consumption, concentrations of dioxins in subjects living around the incinerators correlated positively with their intake of local animal fat, with almost a doubling in subjects with the highest fat intake. These results indicate that dioxins and coplanar PCBs emitted by MSWIs can indeed accumulate in the body of residents who regularly consume animal products of local origin.

We report on the use of a state-of-the-art method for the measurement of selected polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and polychlorinated biphenyls in human serum specimens. The sample preparation procedure is based on manual small size solid-phase extraction (SPE) followed by automated clean-up and fractionation using multi-sorbent liquid chromatography columns. SPE cartridges and all clean-up columns are disposable. Samples are processed in batches of 20 units, including one blank control (BC) sample and one quality control (QC) sample. The analytical measurement is performed using gas chromatography coupled to isotope dilution high-resolution mass spectrometry. The sample throughput corresponds to one series of 20 samples per day, from sample reception to data quality cross-check and reporting, once the procedure has been started and series of samples keep being produced. Four analysts are required to ensure proper performances of the procedure. The entire procedure has been validated under International Organization for Standardization (ISO) 17025 criteria and further tested over more than 1500 unknown samples during various epidemiological studies. The method is further discussed in terms of reproducibility, efficiency and long-term stability regarding the 35 target analytes. Data related to quality control and limit of quantification (LOQ) calculations are also presented and discussed.

A comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC x GC-TOF-MS) experimental setup was tested for the measurement of seven 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs), ten 2,3,7,8-substituted polychlorinated dibenzofurans (PCDFs), four non-ortho-polychlorinated biphenyls (PCBs), eight mono-ortho-PCBs, and six indicator PCBs (Aroclor 1260) in foodstuff samples. A 40m RTX-500 (0.18mm I.D., 0.10 microm df) was used as the first dimension (1D) and a 1.5 m BPX-50 (0.10mm I.D., 0.10 microm df) as the second dimension (2D). The GC x GC chromatographic separation was completed in 45 min. Quantification was performed using 13C-label isotope dilution (ID). Isotope ratios of the selected quantification ions were checked against theoretical values prior to peak assignment and quantification. The dynamic working range spanned three orders of magnitude. The lowest detectable amount of 2,3,7,8-TCDD was 0.2 pg. Fish, pork, and milk samples were considered. On a congener basis, the GC x GC-ID-TOF-MS method was compared to the reference GC-ID high resolution mass spectrometry (HRMS) method and to the alternative GC-ID tandem-in-time quadrupole ion storage mass spectrometry (QIST-MS/MS). PCB levels ranged from low picogram (pg) to low nanogram (ng) per gram of sample and data compared very well between the different methods. For all matrices, PCDD/Fs were at a low pg level (0.05-3 pg) on a fresh weight basis. Although congener profiles were accurately described, RSDs of GC x GC-ID-TOF-MS and GC-QIST-MS/MS were much higher than for GC-ID-HRMS, especially for low level pork and milk. On a toxic equivalent (TEQ) basis, all methods, including the dioxin-responsive chemically activated luciferase gene expression (DR-CALUX) assay, produced similar responses. A cost comparison is also presented.

The impact of a recently closed old municipal solid waste incinerator (MSWI) on polychlorodibenzo-p-dioxin (PCDD), polychlorodibenzofuran (PCDF), and polychlorinated biphenyl (PCB) levels in the surrounding environment and resident serum has been studied in a small rural area of France. Studied soils and eggs from chickens foraging on these soils were sampled in the vicinity of the MSWI underthe prevailing wind stream, while comparison samples were collected outside the assumed impact zone. PCB levels observed in soils and eggs did not differ statistically from comparison sites. This confirmed the low impact of MSWI PCB emission on environmental media, compared to other well-known sources. PCDD/PCDF levels in soils and eggs were significantly higher than in comparison samples, pointing out the impact of MSWI emission on the surrounding environment. The high dioxin concentrations in eggs set aside for private consumption would increase the dioxin intake for the studied population. Blood specimens of 10 nonoccupationally exposed volunteers who had lived within a 2 km radius of the incinerator for at least 25 years have been analyzed. When adjusted for age, PCB and PCDD/F blood levels were higher than general European populations and comparable to a similarly exposed Belgian population.

A new method using comprehensive two-dimensional gas chromatography and isotope dilution time-of-flight mass spectrometry (GCxGC-IDTOFMS) for the simultaneous measurement of selected polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and brominated flame retardants is presented. In contrast to the reference methods based on classical GC/MS, a single injection of the extract containing all compounds of interest results in accurate identification and quantification. Using GCxGC ensures the chromatographic separation of most compounds, and TOFMS allows mass spectral deconvolution of coeluting compounds as well as the use of (13)C-labeled internal standards for quantification. Isotope ratio measurements of the most intense ions for both native and labels ensure the required specificity. The use of this new method with an automated sample preparation procedure developed at the Centers for Disease Control and Prevention (CDC) for the analysis of human serum and milk compared favorably to conventional isotope-dilution one-dimensional gas chromatography-high-resolution mass spectrometry (GC-IDHRMS) for the different human serum and milk pools tested. The instrumental detection limits ranged between 0.5 pg/microL and 10 pg/microL and the method detection limits ranged between 1 and 15 pg/microL (N = 59 analytes). The reproducibility of the method was almost as good as with GC-IDHRMS, the relative standard deviations ranging between 1 and 11% for OCPs measured in human serum. OCP, PBDE, and PCB levels measured using the two methods were highly correlated, and the deviations between the two methods were below 20% for most analytes with concentrations above 1 ng/g milk lipids.

The separation of the 209 polychlorinated biphenyl (PCB) congeners has been studied using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC x GC-TOFMS). Four column combinations based on thermally stable phases, DB-1/HT-8, DB-XLB/HT-8, DB-XLB/BPX-50, and HT-8/BPX-50, have been investigated. The HT-8/BPX-50 set produced the best separation. The distribution of the 100 to 150 ms wide peaks was highly structured in the chromatographic space and based on the degree of ortho-substitution within each separated homologue series. A total of 192 congeners were resolved in 146 min (1.3 analyte per min) using this column set. Eight coelutions involved 17 congeners. Among them, seven congeners were present in Aroclors at levels >1.0 wt.% (CBs 33, 47, 48, 95, 97, 163, 187). Except for CBs 47 and 48, none of the major constituents of commercial mixtures were coeluting. CB 138 was well separated from CBs 163 and 164 in the second dimension. For all column sets, CBs 20, 33, and 109 always coeluted with other PCBs. The 12 toxic dioxin-like congeners (CBs 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, 189), and the seven European Union marker PCBs (CBs 28, 52, 101, 118, 138, 153, 180) were separated from any interfering congeners. This was not the case for the other investigated column sets.

Six polybrominated diphenyl ethers (PBDEs), one hexabromobiphenyl [polybrominated biphenyl (PBB)], and one hexachlorobiphenyl [polychlorinated biphenyl (PCB)] were measured in 40 human serum pools collected in the southeastern United States during 1985 through 2002 and in Seattle, Washington, for 1999 through 2002. The concentrations of most of the PBDEs, which are commercially used as flame retardants in common household and commercial applications, had significant positive correlations with time of sample collection, showing that the concentrations of these compounds are increasing in serum collected in the United States. In contrast, PCB and PBB levels were negatively correlated with sample collection year, indicating that the levels of these compounds have been decreasing since their phaseout in the 1970s.

A method for the high-throughput analysis of human serum for the 38 most prevalent polychlorinated biphenyls (PCBs) based on the use of fast gas chromatography-isotopic dilution time-of-flight mass spectrometry (GC-IDTOFMS) is presented. The chromatographic separation time was 8 min. The separation of the congeners was carried out either chromatographically or analytically using the mass spectral deconvolution capability of the TOFMS. The instrument and the method limits of detection (LODs) were 0.5 pg microL(-1) and 20 pg microL(-1), respectively, which is not as good as the one achieved using high resolution mass spectrometry (HRMS) but allows the detection and quantification of the prevalent PCBs present in real human serum samples. The dynamic range covered 3 orders of magnitude. The comparison with the high resolution mass spectrometry (HRMS) reference method (28 min) was good and some separation improvements have been observed. This method allows the analysis of 100 samples per day per instrument.

A semiautomated extraction and cleanup method has been developed for the measurement of eight polybrominated diphenyl ethers (PBDEs), 2,2',4,4',5,5'-hexabromobiphenyl (BB-153) and 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153). The method employs automated addition of internal standards ((13)C-labeled), addition of formic acid (denaturation agent), and dilution with water prior to automated overnight extraction using a modular solid-phase extraction (SPE) system. Removal of coextracted biogenic materials was performed on a two-layered 3-mL disposable cartridge containing activated silica gel and a mixture of silica gel and sulfuric acid. Sample cleanup was automated using the same modular SPE system. Reproducibility and precision of the liquid handler used for internal standard additions were shown to be 2 and 4%, respectively. Overall reproducibility during processing of eight batches of samples (N = 30/batch, including methods blanks) was below 10% for most analytes. Mean recoveries of the (13)C-labeled internal standards ranged from 69 to 95% for the seven monitored PBDEs; 76 and 98% were recovered for BB-153 and CB-153, respectively.

Congener-specific analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) were performed on twenty-eight non-pooled fast food samples collected in Belgium, Switzerland, Czech Republic, United States of America and Australia. PCDD/F and PCB concentrations for the four investigated types of meals were very low. PCDD/F values ranged from non-detected to 1.40 pg WHO-TEQ/g fat and from 0.79 to 2.08 pg WHO-TEQ/g fat for lower and upper bound, respectively. Major contributors to the PCDD/F TEQ were 1,2,3,4,7,8-HxCDD, 1,2,3,6,7,8-HxCDD, 2,3,7,8-TCDF and 2,3,4,7,8-PeCDF. The relative contribution of PCBs to the total TEQ was 68%. For adults, an average estimated intake was 6.7 pg WHO-TEQ/kg bw/month, including consumption of all types of analyzed meals, representing 9.5% of the PTMI. For child, a value of 14.5 pg WHO-TEQ/kg bw/month was obtained, representing 20.6% of the PTMI.

Dioxins and polychlorinated biphenyls (PCBs) are persistent organic pollutants widely distributed in the food chain, which is the main source of human exposure. Their effects on human health at background exposure levels are still poorly understood. Recent epidemiological evidence suggests a possible association between these pollutants and diabetes. We report here the results of a population-based study in Belgium on 257 (142 women and 115 men) environmentally exposed subjects, including 10 cases of endometriosis and nine cases of diabetes. Seventeen 2,3,7,8-polychlorinated dibenzodioxins/dibenzofurans (PCDD/Fs or dioxins), four coplanar PCBs (International Union of Pure and Applied Chemistry [IUPAC] nos 77, 81, 126 and 169) and 12 PCB markers (IUPAC nos 3, 8, 28, 52, 101, 118, 138, 153, 180, 194, 206 and 209) were quantified in serum fat from fasting blood samples in order to estimate the body burden of these pollutants. Whilst no difference was found between women with endometriosis and their controls, diabetic patients had significantly increased serum levels of dioxins, coplanar PCBs and the 12 PCB markers. After adjustment for age and other covariates, serum total toxic equivalent activity (sum of PCDD/Fs and coplanar PCBs) and 12 PCB marker concentrations in diabetics were 62% (p = 0.0005) and 39% (p = 0.0067) higher, respectively, than in controls. The risk of diabetes was significantly increased in subjects in the top decile for adjusted concentrations of dioxins (odds ratio 5.1, 95% confidence interval [CI] 1.18-21.7), coplanar PCBs (odds ratio 13.3, 95% CI 3.31-53.2) or 12 PCB markers (odds ratio 7.6, 95% CI 1.58-36.3). These findings warrant further studies to assess the significance of the associations between diabetes and environmental exposure to polychlorinated pollutants.

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.

Congener-specific analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and non-ortho (coplanar) polychlorinated biphenyls (cPCBs) were performed on 20 non-pooled breast milk samples collected in or close to an industrial area of Wallonia (Belgium). PCDD/F concentrations ranged between 16.0 and 52.1 pg TEQ/g fat, with a mean value of 29.4 pg TEQ/g fat. If coplanar PCBs (77, 126, 169) are included in TEQ calculations, levels ranged between 22.2 and 100.2 pg TEQ/g fat, with a mean value of 40.8 pg TEQ/g fat. It appears that 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF and PCB-126 account for more than 90% of the TEQ. Estimated PCDD/F dietary intake is 76 pg TEQ/kg body weight (bw)/day. This value is almost 20 times higher than the World Health Organization tolerable daily intake. A value of 103 pg TEQ/kg bw/day represents the intake of PCDDs, PCDFs and cPCBs (no mono-ortho PCBs included).

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 197 foodstuffs samples of animal origin from Belgium during years 2000 and 2001. All investigated matrices (except horse) present background levels lower than the Belgian non-commercialization value of 5 pg TEQ/g fat. Pork was the meat containing the lowest concentration of both PCDD/Fs and cPCBs. The mean background concentration of 2,3,7,8-TCDD toxicity equivalent in milk was 1.1 pg/g of fat, with a congener distribution typical of non-contaminated milk. The relative contribution of 2,3,7,8-TCDD, 2,3,7,8-TCDF, 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF to the PCDD/Fs TEQ was 85+/-7.9% for all investigated matrices. The cPCBs contribution to the total TEQ was 47+/-19.0% for products of terrestrial species and 69+/-20.0% for aquatic species. Once the contribution of cPCBs was added to the TEQ, few foodstuffs such as horse, sheep, beef, eggs and cheese presented levels above the future European guidelines that currently only include PCDD/Fs but will be re-evaluated later in order to include 'dioxin-like' PCBs. Based on levels measured in the samples, the estimation of the dietary intake was 65.3 pg WHO-TEQ/day for PCDD/Fs only (1.00 pg WHO-TEQ/kg bw/day, for a 65 kg person) and 132.9 pg WHO-TEQ/day if cPCBs were included (2.04 pg WHO-TEQ/kg bw/day, for a 65 kg person). Meat (mainly beef), dairy products, and fish each account for roughly one third of the intake.

A fast clean-up procedure for the low level analysis of polychlorinated dibenzo-p-dioxins. polychlorinated dibenzofurans and coplanar polychlorinated biphenyls in highly fatty biological matrices using high capacity disposable multi-layer silica columns is presented. Results were compared with gel permeation chromatography for removal of lipids. Analytical criteria such as recovery rates, repeatability, reproducibility and robustness are evaluated through a broad range of biological matrices and reference materials analysis. The final proposed procedure for the complete analysis, including pressurized liquid extraction, Power-Prep system clean-up and GC-high-resolution MS analysis requires only 48 h, and allows the simultaneous preparation of up to 10 samples.