Total Polychlorinated Biphenyls Concentrations Research Articles

Determination of polychlorinated biphenyls in marine fish obtained from tsunami-stricken areas of Japan.

We determined the polychlorinated biphenyl (PCB) congeners in 101 marine fish obtained from tsunami-stricken areas following the Great East Japan Earthquake in 2011. In particular, to determine the degree of PCB contamination in the fish, we investigated the concentration of total PCB (∑PCB) and the proportions of 209 individual PCB congeners by high-resolution gas chromatography/high-resolution mass spectrometry. The ∑PCB concentration was 1.7–33 ng/g in fat greenling (n = 29), 0.44–25 ng/g in flounder (n = 36), and 1.6–86 ng/g in mackerel (n = 36), all values being much lower than the provisional regulatory limit in Japan. In the congener analysis, tetra-, penta-, hexa-, and hepta-chlorinated PCB congeners dominated in all samples (comprising over 86% of the ∑PCB). The proportions of the chlorinated PCB congeners were similar to the contamination patterns derived from Kanechlor in the environment, implying that the marine fish were not contaminated with fresh PCBs.

Organochlorine pesticides and polychlorinated biphenyls in sewage sludge from Egypt

ABSTRACTThe purpose of this study was to determine the levels, distribution and toxicological potential of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in sewage sludge samples from several WWTPs in the Alexandria area, Egypt. The POPs of interest were 26 PCBs and 16 OCPs. Analyses were performed by gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode (GC-MS-SIM) using deuterated organochlorines as internal standards. Total concentrations of OCPs and Σ7 PCBs (ICES) in sludge ranged from 44.2 to 489 μg/kg dw. and 5,600 to 11,000 μg/kg dw., respectively. The highest concentration levels were found for PCBs, HCHs, DDTs, and HCB, in this order. The PCB homologue profiles in sludge samples were dominated by penta- and hexa-chlorinated biphenyls. Seasonal variations were observed for OCPs with higher levels in summer, which reflects more usage in warmer climates. Composite profiles of OCP metabolites indicated new inputs of lindane and technical endosulfan and earlier usage of DDT and technical chlordane. Contamination levels of OCPs and PCBs for Egyptian sludge can be categorized as moderate to high compared to other countries worldwide. The OCP content in none of the samples exceeded limits set by the European Commission for use of sludge in agriculture; while all the concentrations of PCBs in sludge samples were higher by one order of magnitude than the upper limit for land application.

Remediation of PCB-contaminated soil using a combination of mechanochemical method and thermal desorption.

The combination of mechanochemical method and thermal desorption for remediating polychlorinated biphenyls (PCBs) in contaminated soil was tested in this study. The effects of grinding time and heating time on PCB removal efficiency were investigated. The contaminated soil, mixed with CaO powder at a weight ratio of 1:1, was first ground using a planetary ball mill. After 4h of grinding, the total PCB concentration and its toxic equivalence quantity (TEQ) decreased by 74.6 and 75.8%, respectively. Then, after being heated at 500°C for 60min, the residual PCBs in mechanochemical + thermal treated soil decreased to 247ng/g, resulting in a removal efficiency of 99.95%. The removal effect can be promoted by longer grinding time and heating time; however, increased energy consumption was inevitable. The combination of grinding time and heating time should be optimized in a practical remediation process.

Distribution of persistent organic pollutants in aggregate fractions of a temperate forest and semi-rural soil

The fate of persistent organic pollutants (POPs) and their interactions with aggregates of forest soils are not completely understood. Our objectives here were to quantify the distribution of different POPs in water-stable aggregate fractions and to study their influence on soil organic carbon (Corg) content. Soil samples were taken from a forest-site, Gogerddan (G) and a semi-rural site, Hazelrigg (H) in Great Britain, from 0–2 and 2–5 cm and 0–4 and 8–12 cm soil depth, respectively. POPs analyzed were PAHs, PCBs, total DDT, PBDEs and HCB. The bulk soil analysis showed that the concentration of POPs was significantly higher (p ≤ 0.05) in forest site G than in semi-rural site H, particularly at the surface soil levels compared to the subsurface soil depths in both sites. Total concentrations of PCBs and PAHs of both sites were positively correlated with Corg contents. POPs concentrations and Corg, Nt contents of forest site G were significantly higher (p ≤ 0.05) in water-stable macro aggregates (>0.25, >1, >2 mm) than the micro aggregates (>0.053 mm). The POP concentrations of all aggregate fractions after normalizing to their respective Corg content were increased due higher contamination and strong sorption by Corg. These results showed a strong effect of Corg on the partitioning of organic pollutants to soil aggregate size fractions. The present study affirms the ecological significance of forest soils act as a potential sink of POPs. In summary, our results suggest that aggregate fractions may promote soil C storage and act as a potential POP sink in surface soil without increasing their concentration in the aggregate fraction of subsoil.

Depositional history and inventories of polychlorinated biphenyls (PCBs) in sediment cores from an Antarctic Specially Managed Area (Admiralty Bay, King George Island)

Temporal patterns, fluxes and inventories of polychlorinated biphenyls (PCBs) were assessed in nine sediment cores collected from selected areas of Admiralty Bay off the Antarctic Peninsula. Concentrations of total PCBs were low, but slightly higher in comparison to low-impacted, remote environments in the world, ranging from below the detection limit to 11.9ngg−1 in dry weight. PCB concentrations and inventories suggest a possible minor influence related to the nearby logistic activities, especially in the sediment core collected close to the Ferraz Station. Despite being the most remote and protected area on the planet, the Antarctic continent is no longer a pristine environment.

Exploration of potential biomarkers and related biological pathways for PCB exposure in maternal and cord serum: A pilot birth cohort study in Chiba, Japan

Polychlorinated biphenyls (PCBs) have been associated with adverse human reproductive and fetal developmental measures or outcomes because of their endocrine-disrupting effects; however, the biological mechanisms of adverse effects of PCB exposure in humans are not currently well established. In this study, we aimed to identify the biological pathways and potential biomarkers of PCB exposure in maternal and umbilical cord serum using a hydrophilic interaction chromatography-tandem mass spectrometry (HILIC-MS/MS) metabolomics platform. The median concentration of total PCBs in maternal (n=93) and cord serum (n=93) were 350 and 70pgg−1 wet wt, respectively. PCB levels in maternal and fetal serum from the Chiba Study of Mother and Children's Health (C-MACH) cohort are comparable to those of earlier cohort studies conducted in Japan, the USA, and European countries.We used the random forest model with the metabolome profile to predict exposure levels of PCB (first quartile [Q1] and fourth quartile [Q4]) for pregnant women and fetuses. In the prediction model for classification of Q1 versus Q4 (area-under-curve [AUC]: pregnant women=0.812 and fetuses=0.919), citraconic acid level in maternal serum and ethanolamine, p-hydroxybenzoate, and purine levels in cord serum had >0.70 AUC values. These candidate biomarkers and metabolite included in composited models were related to glutathione and amino acid metabolism in maternal serum and the amino acid metabolism and ubiquinone and other terpenoid-quinone biosynthesis in cord serum (FDR <0.10), indicating disruption of metabolic pathways by PCB exposure in pregnant women and fetuses. These results showed that metabolome analysis might be useful to explore potential biomarkers and related biological pathways for PCB exposure. Thus, more detailed studies are needed to verify sensitivity of the biomarkers and clarify the biochemical changes resulting from PCB exposure.

Characteristics and potential sources of polychlorinated biphenyl pollution in a suburban area of Guangzhou, southern China

In this study, 52 paired gas and particle samples were collected from a suburban field in Guangzhou in 2012 using a high-volume active air sampler; they were then analysed for 30 polychlorinated biphenyl (PCB) congeners via gas chromatography with tandem mass spectrometry. Total PCB concentrations ranged from 97.4 to 853 pg m−3. This was a moderate level compared with other cities, undeveloped areas, and electronic waste disposal sites. Atmospheric concentrations of PCBs did not exhibit notable diurnal or seasonal variations, except for a few high measurement. Tetra- and tri-CBs were the predominant PCB compounds, with an average combined contribution of 81.9%. CB-77 was the dominant congener in the particle phase due to a few samples with extremely high mass fraction of CB-77 and relatively low concentrations of other PCBs. Based on measurements of pollution characteristics including diurnal and seasonal variations, we used correlation analysis, principal component analysis and back trajectory modeling to deduce that electronic manufacturing and recycling activities, pigment/paint production, and waste incineration plants are possible sources of PCBs in Guangzhou. Of these sources, the high observed contributions of CB-77 originated mainly from the pigment/paint industry.

Monitoring and risk assessment of polychlorinated biphenyls (PCBs) in agricultural soil from two industrialized areas.

For monitoring and risk assessment, levels and distributions of Σ29 PCBs in paddy soil samples collected from Gwangyang (10 sites) and Ulsan (20 sites), heavily industrialized cities in Korea, were investigated using high-resolution gas chromatography/high-resolution mass spectrometry. Overall, total concentrations of Σ29 PCBs in Gwangyang (216.4-978.6pgg-1 dw) and Ulsan (273.8-1824.1pgg-1 dw) were higher than those (106.6-222.6pgg-1 dw) in agricultural soil from Anseong in Korea. The TEQ (toxic equivalency) values from Gwangyang (0.06-0.40ng TEQ kg-1 dw) and Ulsan (0.06-0.22ng TEQ kg-1 dw) were higher than those (0.04-0.11ng TEQ kg-1 dw) in Anseong but lower than the WHO threshold level (20ng TEQ kg-1). However, one of the most toxic congeners, PCB 126, gave the highest concentration, possibly posing a risk to the biota. Seven indicator PCB congeners contributed to 50-80% of the total concentration of Σ29 PCBs, indicating the 7 PCBs can be used as valuable indicators for monitoring. The principal component analysis and cluster analysis for the homologue profiles of PCBs indicated that all the samples from both cities had the similar PCB contamination patterns, and the major sources of the PCB contamination were most likely from the usage of Aroclor 1254 than those of Aroclors 1242 and 1260. These PCB technical mixtures were possibly significantly used by various industries including iron and steel industries in Gwangyang and petrochemical and shipbuilding industries in Ulsan.

Emissions of Selected Semivolatile Organic Chemicals from Forest and Savannah Fires.

The emission factors (EFs) for a broad range of semivolatile organic chemicals (SVOCs) from subtropical eucalypt forest and tropical savannah fires were determined for the first time from in situ investigations. Significantly higher (t test, P < 0.01) EFs (μg kg-1 dry fuel, gas + particle-associated) for polycyclic aromatic hydrocarbons (∑13 PAHs) were determined from the subtropical forest fire (7,000 ± 170) compared to the tropical savannah fires (1,600 ± 110), due to the approximately 60-fold higher EFs for 3-ring PAHs from the former. EF data for many PAHs from the eucalypt forest fire were comparable with those previously reported from pine and fir forest combustion events. EFs for other SVOCs including polychlorinated biphenyl (PCB), polychlorinated naphthalene (PCN), and polybrominated diphenyl ether (PBDE) congeners as well as some pesticides (e.g., permethrin) were determined from the subtropical eucalypt forest fire. The highest concentrations of total suspended particles, PAHs, PCBs, PCNs, and PBDEs, were typically observed in the flaming phase of combustion. However, concentrations of levoglucosan and some pesticides such as permethrin peaked during the smoldering phase. Along a transect (10-150-350 m) from the forest fire, concentration decrease for PCBs during flaming was faster compared to PAHs, while levoglucosan concentrations increased.

Study of polychlorinated biphenyls (PCBs) in soil samples from Al-Ahdab oil field in Waset region/Iraq

Levels of twelve Polychlorinated biphenyls (PCBs) were studied in soil samples collected from the vicinity of the Ahdab oil field in Kut area/Iraq. All the samples were extracted, cleaned up and analyzed using GC/MS for dioxin-like PCBs. The total concentration of PCBs ranged between 38 μg/kg (site 16) and 980 μg/kg (site 15) with a total mean concentration of 270 μg/kg. Pentachlorobiphenyls were the predominant PCB congeners, accounting for 57.6% of the total PCB concentration found in the soil samples. The toxicity equivalents (TEQ PCBs) in all the soil samples were found in the range of 0.01–35.66 μg TEQ/kg which is 400-fold higher than other studies. Sixteen of the 24 studied soil samples show a carcinogenity higher than the allowable concentration of 5 μg WHO-TEQ/kg.

Bioconcentration may be favoured over biomagnification for fish PCB contamination in high altitude lakes

Cold aquatic ecosystems such as high altitude alpine lakes are expected to act as long-term sinks of polychlorinated biphenyls (PCBs), the burden of which might even be intensified by global warming. Because the physical, chemical, and biological structures of high altitude lakes are highly responsive to climate change, both PCB exposure and bioaccumulation are likely to be strongly altered in the near future. Yet, in the absence of mechanistic knowledge of the processes regulating fish contamination with PCB in such ecosystems, their fate cannot be predicted. The aim of this study was to investigate the relative roles of biomagnification and bioconcentration on the individual, seasonal, and between-site variability of fish PCB contamination in 2 alpine, high altitude lakes. The intra- and within-lake variability of fish PCBs was not related to differences in fish physiology (size, age, or lipid content) and only marginally tied to fish feeding habitats (assessed from fatty acid composition and δ13C) or trophic position (δ15N). These results suggested that the trophic pathway and biomagnification contributed little to the observed differences in fish PCB concentrations between lakes, seasons, and individuals. Moreover, the fish PCB levels did not depend on the total PCB concentration in the water, but the fish contamination dynamics during the spring thaw pointed to a significant role of dissolved PCBs during this season in both lakes. In high altitude lakes, low temperatures might contribute to kinetically limit equilibrium with dietary PCBs, thereafter favouring bioconcentration over biomagnification pathways by which fish become contaminated with PCBs.

Polybrominated diphenyl ether, polychlorinated biphenyl, and dechlorane plus concentrations in human serum, and their relationships with thyroid hormones.

Persistent halogenated organic compounds, including polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and dechlorane plus (DP), were determined in human serum collected in Weifang and Nanning, China, and the relationships between their concentrations and thyroid hormone concentrations were determined. The total PBDE (Σ10PBDEs), total PCB (Σ14PCBs), and total DP (ΣDP) concentrations were higher in Weifang (medians 220, 4.3, and 2.2 ng/g lipid, respectively) than in Nanning (medians 180, 1.9, and 1.5 ng/g lipid, respectively). The donors’ ages correlated with Σ14PCBs but not with Σ10PBDEs or ΣDP in Weifang. Age positively correlated with Σ10PBDEs but not Σ14PCBs and ΣDP in Nanning. The correlations between the individual PBDE, PCB, and DP congener and thyroid hormone concentrations were analyzed by stepwise multiple linear regression after log2-transforming the variables. Triiodothyronine (T3) concentrations were associated with BDE-99 concentrations and ΣDP in Weifang but with BDE-153 concentrations and Σ10PBDEs in Nanning. A positive correlation was found, for the first time, between anti-DP and free-T3 concentrations in Weifang, but free-T3 concentrations correlated with PCB-118 and PCB-170 concentrations in Nanning. Thyroxine (T4) concentrations correlated with total dioxin-like PCB concentrations in Weifang but with PCB-156 concentrations in Nanning. No significant correlations were found between the analyte and free-T4 concentrations in Weifang, but negative correlations were found between free-T4 and total dioxin-like PCB and BDE-190 concentrations in Nanning. No significant correlations were found between the analyte and thyroid-stimulating hormone (TSH) concentrations in Weifang but negative correlations were found between Σ10PBDEs and the TSH concentrations in Nanning. The correlations between the analyte and thyroid hormone concentrations followed different trends in Weifang and Nanning but were similar to those that have been found in animal and epidemiological studies.

Levels, Sources, and Risk Assessment of Polychlorinated Biphenyls (PCBs) in Soils from Industrial Areas: A Case Study from Saudi Arabia

ABSTRACTThe objective of this study was to assess the pollution levels, sources, and human health risk of polychlorinated biphenyls (PCBs) in soils of industrial areas of the central and eastern regions of Saudi Arabia. Therefore, the surface soil samples from industrial areas (cement kiln, oil refinery, electric power plant, steel industry, and desalination plant) were collected and analyzed by High-Resolution Gas Chromatography-Mass Spectrometry/Mass Spectrometry-Time of Flight (HRGC-MS/MS-TOF) to quantify the levels of 26 PCBs (including 12 dioxin-like PCBs and 14 indicator-PCBs). The investigated 26 PCBs were detected in all soil samples. The total PCBs concentration (from tri-CBs to hepta-CBs) ranged from 171 to 4892 pg g−1 with an average of 1369 pg g−1 in soils of the central region and of 142–1231 pg g−1 with an average of 302 in soils of the eastern region, showing higher values at cement factory and/or oil refinery sites. Overall, the indicator-PCBs were the main congeners and contributed dominantly to the total mass of PCBs in comparison with the dioxin-like PCB congeners, with the most abundant for PCB-180 in the soil samples of the central region. Among individual dioxin-like PCBs, PCB-126 had the highest average value of the toxicity equivalence (TEQ). The TEQ values of ∑12dioxin-like PCBs did not exceed the Canadian soil quality guidelines of dioxin (4 pg TEQ g−1). Based on human health risk assessment via ingestion, dermal contact, and inhalation, low adverse effects of PCBs could be expected as indicated by lower values of cancer risk (≤10−6). The principal component analysis indicated that there is a different source of PCBs with similar or different PCB profiles.

Historical sources of polychlorinated biphenyls to the sediment of the New York/New Jersey Harbor

Using dated sediment cores, polychlorinated biphenyl (PCB) congener concentrations in the New York/New Jersey Harbor and Lower Hudson River were investigated using Positive Matrix Factorization. Of the seven factors resolved, six represent Aroclors in various stages of weathering. Factor 1 resembles Aroclor 1242 and is consistent with the Upper Hudson River PCB signal associated with the General Electric capacitor plants near Hudson Falls, NY. This factor is the dominant source of PCBs in the upper layers of the sediment core collected in the Lower Hudson River. Factor 2 (Aroclor 1248) was the dominant PCB component in the core depths corresponding with around 1970, but it has decreased more rapidly since its peak (estimated half-life of about 5 years) than factor 1 (half-life of about 14 years), suggesting that PCBs from the Upper Hudson have delayed the recovery of the Harbor from PCB contamination. The seventh factor, comprised of PCBs 206, 208, and 209, was greatest in concentration in the deepest core slices and is thought be associated with inadvertent production of PCBs during the manufacture of titanium dioxide and/or with foundry waxes containing PCBs. PCB 11, which is thought to be associated with the use of color organic pigments, was examined separately and was detected in sediment throughout the Harbor. Its maximum concentrations generally occurred at the same depth as the maximum total PCB concentrations, suggesting that PCB 11 concentrations decreased after the mid-1970s.

Enrichment, isolation and biodegradation potential of psychrotolerant polychlorinated-biphenyl degrading bacteria from the Kongsfjorden (Svalbard Islands, High Arctic Norway)

Persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), have been detected in abiotic Arctic matrices: surface sediments and seawater from coastal areas in the Kongsfjorden were collected and analyzed. Levels of PCBs varied depending on the sampling site. Total PCB concentrations were between 11.63 (site C2W) and 27.69pgl−1 (site AW). These levels were comparable to those reported previously in lake sediments from the northern Svalbard.The occurrence and biodegradation potential of cold-adapted PCB-oxidizing bacteria in seawater and sediment along the fjord was also evaluated. After enrichment with biphenyl, 246 isolates were obtained with 45 of them that were able to grow in the presence of the PCB mixture Aroclor 1242, as the sole carbon source. The catabolic gene bphA was harbored by 17 isolates with affiliates to the genera Algoriphagus, Devosia and Salinibacterium that have been never reported as able to utilize PCBs, thus deserving further investigation. The total removal of Aroclor 1242 and selected PCB congeners was evaluated at 4 and 15°C for eight bphA-harboring isolates and Gelidibacter sp. DS-10. With few exceptions, tested strains showed greater efficiency at 15 than at 4°C. Isolates were able to reduce most chromatographic peaks by >50%, with some di- and trichlorobiphenyls that were quite totally removed (>90%).

Factors influencing the atmospheric concentrations of PCBs at an abandoned e-waste recycling site in South China

The diurnal atmospheric concentrations of polychlorinated biphenyls (PCBs) were investigated at an abandoned e-waste recycling site in South China during winter and summer. Total PCB concentrations during winter and summer were 27.6–212 and 368–1704pg/m3 in the particulate phase and 270–697 and 3000–15,500pg/m3 in the gaseous phase, respectively. Both gaseous and particulate PCB concentrations and compositions exhibited significant difference between winter and summer samples, but no diurnal variations during the measurement period. The correlation analysis between PCB concentrations and meteorological conditions, including atmospheric temperature, humidity, and mixing layer height, suggested that the seasonal variability of atmospheric PCB concentrations was strongly temperature-dependent, while the diurnal variability was probably source-dependent. The temperature-driven variations can also be proved by the significant linear correlation between ln P and 1/T in the Clausius-Clapeyron plot. Although government has implemented controls to reduce e-waste pollution, both the relatively high concentrations of PCBs and the diurnal variation in the air suggested that emissions from occasional e-waste recycling activities may still exist in this recycling area. These results underline the importance of continuing e-waste recycling site management long after abandonment.

Particle size distribution and gas-particle partitioning of polychlorinated biphenyls in the atmosphere in Beijing, China.

Size-fractionated samples of urban particulate matter (PM; ≤1.0, 1.0-2.5, 2.5-10, and >10μm) and gaseous samples were simultaneously obtained to study the distribution of polychlorinated biphenyls (PCBs) in the atmosphere in Beijing, China. Most recent investigations focused on the analysis of gaseous PCBs, and much less attention has been paid to the occurrence of PCBs among different PM fractions. In the present study, the gas-particle partitioning and size-specific distribution of PCBs in atmosphere were investigated. The total concentrations (gas + particle phase fractions) of Σ12 dioxin-like PCBs, Σ7 indicator PCBs, and ΣPCBs were 1.68, 42.1, and 345pg/m3, respectively. PCBs were predominantly in the gas phase (86.8-99.0% of the total concentrations). The gas-particle partition coefficients (K p ) of PCBs were found to be a significant linear correlated with the subcooled liquid vapor pressures (P L0) (R 2=0.83, P<0.01). The slope (m r ) implied that the gas-particle partitioning of PCBs was affected both by the mechanisms of adsorption and absorption. In addition, the concentrations of PCBs increased as the particle size decreased (>10, 2.5-10, 1.0-2.5, and ≤1.0μm), with most of the PCBs contained in the fraction of ≤1.0μm (53.4% of the total particulate concentrations). Tetra-CBs were the main homolog in the air samples in the gas phase and PM fractions, followed by tri-CBs. This work will contribute to the knowledge of PCBs among different PM fractions and fill the gap of the size distribution of particle-bound dioxin-like PCBs in the air.

Occurrence, distribution, and dechlorination of polychlorinated biphenyls and health risk assessment in Selangor River basin.

Polychlorinated biphenyls (PCBs) were monitored in surface water collected in the Selangor River basin, Malaysia, to identify the occurrence, distribution, and dechlorination process as well as to assess the potential adverse effects to the Malaysian population. Ten PCB homologs (i.e., mono-CBs to deca-CBs) were quantitated by using gas chromatography-mass spectrometry (GC/MS). The total concentration of PCBs in the 10 sampling sites ranged from limit of detection to 7.67ngL-1. The higher chlorinated biphenyls (tetra-CBs to deca-CBs) were almost not detected in most of the sampling sites, whereas lower chlorinated biphenyls (mono-CBs, di-CBs, and tri-CBs) dominated more than 90% of the 10 homologs in all the sampling sites. Therefore, the PCB load was estimated to be negligible during the sampling period because PCBs have an extremely long half-life. The PCBs, particularly higher chlorinated biphenyls, could be thoroughly dechlorinated to mono-CBs to tri-CBs by microbial decomposition in sediment or could still be accumulated in the sediment. The lower chlorinated biphenyls, however, could be resuspended or desorbed from the sediment because they have faster desorption rates and higher solubility, compared to the higher chlorinated biphenyls. The health risk for the Malaysia population by PCB intake that was estimated from the local fish consumption (7.2ngkg-1 bwday-1) and tap water consumption (1.5×10-3-3.1×10-3ngkg-1 bwday-1) based on the detected PCB levels in the surface water was considered to be minimal. The hazard quotient based on the tolerable daily intake (20ngkg-1 bwday-1) was estimated at 0.36.

Quantification of all 209 PCB congeners in blood-Can indicators be used to calculate the total PCB blood load?

Polychlorinated biphenyls (PCBs) are a substance group of 209 theoretically possible compounds. The human body burden of PCBs is commonly calculated based on so-called indicator congeners such as PCB 138, PCB 153 and PCB 180, which are analyzed in human blood. The German "Human Biomonitoring (HBM) Commission" assumes that the sum of these indicator congeners multiplied by a factor of 2 represents the total PCB burden. This norm is based on data obtained from exposure studies after dietary intake. Data from indoor air shows a different congener pattern, which might lead to a relatively higher intake of lower chlorinated PCBs by inhalation. In two independent studies with adult participants from two regions in Germany, we measured all 209 PCB congeners in 44 whole blood and 42 plasma samples. Participants from the whole blood study group had additional exposure to PCBs via indoor air. With our analytical method, 141 individual PCB congeners, 27 coeluted pairs of PCB congeners and 2 records of 3 and 4 coeluted PCBs could be determined. Thus, 172 analysis results were reported per sample. In the whole blood samples, 50 congeners showed values below the limit of quantification (LOQ), whereas 94 congeners could not be detected in any of plasma samples. Total PCB concentrations (Σ 209 PCB congeners, incl. ½ LOQ) in the whole blood samples ranged from 99 to 2152ng PCB/g lipid (Median: 454ng/g lipid; 95th Percentile: 1404ng/g lipid). The sum of all 209 measured PCB (incl. ½ LOQ) in plasma samples showed levels between 52 and 933ng PCB/g lipid (Median: 226ng/g lipid; 95th Percentile: 642ng/g lipid). Our results show that the burden of PCBs on the human body is caused mainly by the three highly chlorinated indicator congeners PCB 138, PCB 153 and PCB 180. In median approximately 50% of the total PCB content in human whole blood or plasma samples can be attributed to these congeners. Total PCB, calculated by multiplying the sum of the three indicator congeners by 2, showed a strong and highly significant correlation to the sum of all 209 measured congeners for each sample. A slightly stronger correlation in the whole blood samples could be achieved by choosing six indicator congeners, including the lower chlorinated congeners (PCB 28, 52 and 101) into the calculation. Although this difference is very small, it must be considered that higher PCB levels in indoor air than those measured in the present study might be associated with a higher burden of indoor-air-related congeners in exposed individuals. For precautionary reasons, it could therefore be recommended that the assessment of individuals exposed to PCB via indoor air should be carried out based on the sum of the 6 indicator congeners PCB 28, PCB 52, PCB 101, PCB 138, PCB 153 and PCB 180 multiplied by a factor of 2.

Levels of polychlorinated biphenyls (PCBs) in human adipose tissue from Baghdad/Iraq

The levels of 12 polychlorinated biphenyls (PCBs) in human adipose tissue samples gathered from patients, from three different hospitals, in Bagdad/Iraq were analyzed. All samples were extracted, cleaned up, and analyzed by GC/MS for dioxin-like PCBs. The total mean concentration of PCBs in all human adipose tissues samples was 404 μg/kg. Pentachlorobiphenyls were the predominant PCB congeners, accounting for 62.56% of the total PCB concentration found in the human adipose tissue samples which represent the most toxic compounds between all dioxin-like PCB congeners. The toxicity equivalents (TEQ PCBs) in all human adipose tissue samples were found in the range of 0.0126–86.284 μg TEQ/kg. The present average TEQ of 11.52 μg/kg is within the range that obtained by other studies.