PCBs Congeners Research Articles

Accumulation of organochlorines in the European clam (Ruditapes decussatus) and sediment of the Oualidia lagoon (Morocco).

This study focused on the analysis of organochlorine pesticides and PCBs in tissue samples of the clam, Ruditapes decussatus, in the Oualidia lagoon. Tissue assays were conducted during February to December 2005 and sediment (October 2005) was also tested. 13 organochlorine compounds and eight PCBs congeners were investigated, is HCB, γ-HCH, chlordane, cis-chlordane and trans-nonachlor, DDT and its metabolites DDD, DDE, heptachlor, its epoxide, mirex and PCBs (PCB28 + 50, PCB52, PCB101, PCB 118, PCB138, PCB153, PCB180). Analysis of these compounds was performed using a gas chromatography capillary column and an electron capture detector. Organochlorine contamination of clams and sediments in the lagoon did not exceed tolerable thresholds according to European standards. The levels of tPCB, tDDT and tOCP in clams are high at 49.4, 22.2, and 7.1 ng g(-1) dw respectively. Concentrations of trans nonachlor and mirex are low compared to other chlorinated pesticides. PCB28 + 50, PCB52 and PCB101 show typical values in sediment, at 18.5, 10.8 and 17.8 ng g(-1) dw respectively.

ZnO-nanotaper array sacrificial templated synthesis of noble-metal building-block assembled nanotube arrays as 3D SERS-substrates

This paper describes a ZnO-nanotaper array sacrificial templated synthetic approach for the fabrication of the arrays of nanotubes with tube-walls assembled by building-blocks of Ag-nanoplates, Au-nanorods, Pt-nanothorns or Pd-nanopyramids, thus possessing high-density 3D “hot spots” in sub-10-nm gaps of neighboring building blocks with nano-tips, -corners or -edges. Additionally, these hierarchical nanostructure arrays possess high surface area with rich surface chemistry, being beneficial to capturing the analyte. The Ag-nanoplateassembled nanotube arrays can be used as sensitive surface-enhanced Raman scattering (SERS) substrates with good signal uniformity and reproducibility. Using such Ag hierarchical nanostructure arrays as SERS-substrates, not only has 10−14 M rhodamine 6G been identified, but also 10−7 M polychlorinated biphenyls (PCBs, a notorious class of persistent organic pollutants) are recognized, and even two congeners of PCBs can be identified in a mixture, showing the potential applications of the materials in SERS-based rapid detection of environmental organic pollutants.

Green synthesis of large-scale highly ordered core@shell nanoporous Au@Ag nanorod arrays as sensitive and reproducible 3D SERS substrates.

We present a simple green synthetic approach to large-scale and highly ordered arrays of vertical nanoporous Au nanorods, with an ultrathin Ag-layer in situ electrodeposited on each nanoporous Au nanorod (denoted as core@shell nanoporous Au@Ag nanorod). As both the nanopores within each nanorod and the gaps between the neighboring nanorods create three-dimensional (3D) "hot spots" homogeneously distributed throughout the whole substrate, the core@shell nanoporous Au@Ag nanorod arrays were proved to be sensitive and reproducible surface-enhanced Raman scattering (SERS) substrates. Not only universal probe molecules (rhodamine 6G, R6G) but also nonadsorbing molecules (polychlorinated biphenyls, PCBs) have been detected by using the substrates. After mono-6-thio-β-cyclodextrin (HS-β-CD) was modified to efficiently capture more PCBs molecules, the detection limit of PCBs was further reduced to 5.35 × 10(-7) M. As a trial of practical application, R6G and PCBs with different molar ratios in their mixed solutions were identified, and two congeners of PCBs in their mixture could also be distinguished, showing great potentials in real-time simultaneous detection of multiple pollutants.

Flexible membranes of Ag-nanosheet-grafted polyamide-nanofibers as effective 3D SERS substrates

We report on a synthetic approach to produce self-supported flexible surface-enhanced Raman scattering (SERS) active membranes consisting of polyamide (PA) nanofibers grafted with vertical Ag-nanosheets, via a combinatorial process of electrospinning PA-nanofiber membranes, assembling Au-nanoparticles on the PA-nanofibers as seeds for subsequent growth of Ag-nanosheets, and electrodepositing Ag-nanosheets on the electrospun PA-nanofibers. As a high density of Ag-nanosheets are vertically grown around each PA-nanofiber in the three-dimensional (3D) networked PA-nanofiber membranes, homogeneous nano-scaled gaps between the neighboring Ag-nanosheets are formed, leading to a high density of 3D SERS "hot spots" within the Ag-nanosheet-grafted PA-nanofiber membranes. The Ag-nanosheet-grafted PA-nanofiber membranes demonstrate high SERS activity with excellent Raman signal reproducibility for rhodamine 6G over the whole membrane. For a SERS-based trial analysis of polychlorinated biphenyls (PCBs, a kind of global environmental hazard), the 3D SERS substrate membranes are modified with mono-6-β-cychlodextrin to effectively capture PCB molecules. As a result, not only a low concentration down to 10(-6) M is reached, but also two congeners of PCBs in their mixed solution are identified, showing promising potential in SERS-based rapid detection of trace organic pollutants such as PCBs in the environment.

NDL-PCBs in muscle of the European catfish (Silurus glanis): An alert from Italian rivers

The non-dioxin-like polychlorinated biphenyls (NDL-PCBs) highly contribute to the PCB dietary intake of total PCBs. Most of the NDL-PCBs are assumed through ingestion of contaminated fish and fishery products. Therefore, it is important to quantify their presence in aquatic organisms to evaluate human risks associated with fish consumption. The European catfish is a top food-chain predator and is considered a reliable bio-monitoring tool reflecting the state of the environmental organic pollution. From 2006 to 2009, 54 European catfish were captured in four sites covering the area of the Po River (North Italy), and their muscles were analysed to determine the levels of 18 PCBs congeners. All samples presented detectable levels of 18 congeners and, on average, results showed an important presence of NDL-PCBs. The sum of the six congeners (28, 52, 101, 138, 153, 180 IUPAC) was used as indicator of the total PCBs concentration. The 33% of the samples analysed exceeded the maximum levels of 125ngg−1 set by European regulations in fish. The values measured ranged from 19.7 to 1015.4ngg−1 (mean 135.6±149.8ngg−1).The concentrations of NDL-PCBs were not related to fish weight or sex, while a significant variability was found among sites (p<0.05), according to the geographical location of many industrial activities in the catchment area of the Po River. PCB 153 and 138 were present in higher concentrations (40% and 30% respectively). We hypothesise that this is due to their high resistance to metabolic degradation.

Temporal trends of PCBs in feed and dietary influence in farmed rainbow trout (Oncorhynchus mykiss)

As a rainbow trout producer, Italy is accounted as fifth in the world and second in continental Europe. In this study, the levels of the eighteen PCBs in feed and in trout, showed a statistical significant difference (p<0.01) throughout the years, with a declining trend from 2005 to 2010. This trend shows effectively that quality and safety of trout feeds has greatly improved during the last years and, as a consequence, also the PCBs values in muscle trout, showed a decreasing trend.Moreover, feed Σ18PCBs showed a statistical significant difference (p<0.01) among the analysed brands and was positively correlated (p<0.01 and r=0.451) with the rainbow trout muscle Σ18PCBs. These results showed that the presence of PCBs in trout muscle is directly linked to the chemical quality of aquaculture feed. The most commonly detected PCBs congeners were congeners PCB 153 and PCB 138 in all the three compared brands.

A direct method for the decontamination of a fly ash amended wet soil, artificially polluted with dioxins

Abstract We report hereby the first method of direct treatment of a wet soil containing toxic polychloroderivatives. Using a system with metallic Ca and 5% Rh fixed on charcoal in methanol, soil samples artificially polluted with fly ash containing polychloro-dibenzodioxins (PCDDs), polychloro-dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (co-PCBs), and having 69.2% to 84.6% moisture content, were successfully treated and decontaminated. This treatment afforded excellent hydrodechlorination yields for the 29 most toxic congeners of PCDDs, PCDFs and PCBs (98.3% degradation yield based on toxic equivalent quotient — or TEQ) after a 24 h treatment, at room temperature.

Change of PCBs and forms of heavy metals in sewage sludge during thermophilic anaerobic digestion

Determination of seven congeners of PCBs was carried out for sewage sludge before, during and after thermophilic digestion. The overall content of heavy metals (Zn, Cu, Ni, Cd, Pb, Cr) in sludge before and after digestion was determined. Moreover the concentration of heavy metals in particular chemical fractions of the sludge was analyzed. After the thermophilic digestion total concentration of seven PCBs was reduced by 47%, which suggests that thermophilic digestion affects PCB reduction positively. On the 10th d of the process, concentration of lower chlorinated PCBs increased, whereas those of higher chlorinated PCBs decreased. The thermophilic digestion process showed no accumulation of the studied heavy metals in the mobile fractions (exchangeable and carbonate) of the stabilized sewage sludge, except for nickel. The highest increase in zinc, copper, cadmium, and chromium concentration was observed in the organic-sulfide fraction, whereas the highest increase in lead was found in the residual fraction of the sludge. In case of nickel both fractions of organic-sulfide and exchangeable–carbonate fractions were enriched.

Evaluation of the use of CALUX results for dioxins and dioxin-like PCBs analysis for quantitative human exposure assessments

The objective of this study was to evaluate if the analysis results of dioxins and dioxin-like PCBs in food matrices obtained using the screening CALUX (Chemically Activated LUciferase gene eXpression) method, could be used for quantitative risk assessment.Contamination data of dioxins and dioxin-like PCBs in food matrices (dairy product, eggs, fish, animal fat and vegetable oil) obtained by the CALUX screening method and by the reference method (GC-HRMS) have been compared. Significant differences between the two methods were observed. Median concentrations of dioxins with the CALUX methods for the food matrices are about twice the median concentration of dioxins with the GC-HRMS. These discrepancies indicate that the data obtained using the CALUX method within the framework of the Belgian official control program cannot be used in risk assessment, specifically for an accurate estimation of the dietary intake of dioxins and dioxin-like PCBs. This can be explained, on one hand, by the promiscuous nature of the Aryl hydrocarbon Receptor (AhR) (whose ligand activation is responsible of the response measured in the CALUX assay) as it effectively binds to a large number of diversely shaped compounds not belonging to the 17 dioxins/furans and the 12 dioxin-like PCBs congeners. On the other hand, the assay is implemented as a screening tool for compliance monitoring where emphasis on method performance is required around the maximum levels, leading to a lack of accuracy for lower or higher concentrations.

Ratio variation of congener profiles of PCDD/Fs and dioxin-like PCBs in human milk during lactation

This study investigates the compositional variations, changes in concentrations and contribution of particular congeners of PCDDs, PCDFs, non-ortho PCBs and mono-ortho PCBs in human milk from two mothers sampled during the 12-month lactation period. Total PCDD/F and dioxin-like PCB concentration in milk sampled from the primiparous mother on day 5 after delivery was 37pgTEQ/g fat, and this value decreased significantly by 43% at 12months. In milk sampled from the multiparous mother nursing her second child on day 5 after delivery was 12pgTEQ/g fat, and this value decreased by 40% at 12months. The decrease was statistically significant not for PCDD/Fs, but for dioxin-like PCBs. The ratio variance of the congener profiles of PCDD/Fs and dioxin-like PCBs in the milk remained similar during lactation. Moreover, the congener profiles of PCDD/Fs and dioxin-like PCBs in the milk showed similar percentages for both mothers independent of the lactation event and the number of previous births. The mean daily intake of dioxins by the infant nursed by the primiparous mother and the infant nursed by the multiparous mother up to six months of age was 140 and 46pg TEQ/kg body weight, respectively. From seven to twelve months of age, the mean daily intake was 37 and 13pg TEQ/kg body weight, respectively. Both values decreased by approximately 70%. The reasons why the mothers' body burden of dioxins decreased by breastfeeding and why the infants' daily intake of human milk per body weight decreased as the infant grows older consequently decreased were considered.

PCB congener specific oxidative stress response by microarray analysis using human liver cell line

In this study we have examined the effect of exposure to different congeners of PCBs and their role in oxidative stress response. A metabolically competent human liver cell line (HepG2) was exposed with two prototype congeners of PCBs: coplanar PCB-77 and non-coplanar PCB-153. After the predetermined times of exposure (0–24 h) at 70 μM concentration, the HepG2 cells showed significant apoptotic changes by fluorescent microscopy after 12 h of exposure. Gene set enrichment analysis (GSEA) identified oxidative stress as the predominant enrichment. Further, paraquat assay showed that PCB congeners lead to oxidative stress to different extents, PCB-77 being more toxic. This study, with emphasis on all recommended microarray quality control steps, showed that apoptosis was one of the most significant cellular processes as a result of oxidative stress, but each of these congeners had a unique signature gene expression, which was further validated by Taqman real time PCR and immunoblotting. The pathways involved leading to the common apoptotic effect were completely different. Further in-silico analysis showed that PCB-153 most likely acted through the TNF receptor, leading to oxidative stress involving metallothionein gene families, and causing apoptosis mainly by the Fas receptor signaling pathway. In contrast, PCB-77 acted through the aryl hydrocarbon receptor. It induced oxidative stress through the involvement of cytochrome P450 (CYP1A1) leading to apoptosis through AHR/ARNT pathway.

Multiresidue determination of organochlorines in fish oil by GC–MS: A new strategy in the sample preparation

A rapid, economic and environmentally friendly analytical methodology has been implemented for the determination of alpha-, beta-, gamma- and delta-HCH, p,p'-DDT, p,p'-DDD and p,p'-DDE, PCBs congeners #28, #52, #101, #153, #138 and #180 and Hexachlorobenzene in fish oil. 1,2,3,4-Tetrachloronaphtalene was used as internal standard. The sample preparation, consisting of a single step of clean-up and fractionation, took place in a column filled with different layers of neutral and sulphuric acid modified silica. The analytes were eluted by vacuum with of hexane. Significant reduction in terms of solvents, sorbents, and analysis time was achieved in comparison with literature. Gas chromatography coupled to mass spectrometry was used for the separation and determination of the analytes. The instrumental limits of detection were from 0.1 to 1.3ngmL(-1) and the response of the detector was linear up to 200ngmL(-1). The separation proved to be precise (RSD<3.7% in peak area) and robust in terms of peak area, peak efficacy and resolution. The methodology was validated with two certified reference materials of cod liver oil, BCR 598 and BCR 349, obtaining no statistically significant differences between the concentrations found and certified. For the analytes that were not certified, aliquots of the reference materials were spiked and the recoveries obtained were satisfactory. These results were consistent with those found previously for DDTs by gas chromatography with an electron-capture detector. The methodology was applied to the analysis of three fish oil pills sold in Spain as a dietary supplement of vitamins and omega-3 fatty acids. The sum of the analytes studied was from 64 to 80ngg(-1). The most abundant compounds are PCBs, followed by DDTs in all samples.

Organochlorine Compounds, Iodine Intake, and Thyroid Hormone Levels during Pregnancy

The effect of organochlorine compounds (OCs) on thyroid function, as well as the potential confounding effect of iodine intake, was studied in a large sample of pregnant women from two population-based cohort studies in Sabadell (n = 520) and Gipuzkoa (n = 570), Spain. Thyroid hormones (free T4 and total T3), thyrotropin, and polychlorinated biphenyls (PCB congeners 118, 138, 153, and 180), hexachlorobenzene (HCB), beta-hexachlorocyclohexane (beta-HCH), dichlorodiphenyl dichloroethylene (p'p'-DDE) and dichlorodiphenyl richloroethane (p'p-DDT) were measured in serum samples collected at first trimester of pregnancy. Urinary iodine concentration (UIC) was measured and iodine intake from diet, iodized salt, and supplements were estimated from a food frequency questionnaire. Levels of HCB and PCBs congeners 180, 153, and 138 were related to lowe rtotal T3 levels (adjusted coefficient (SE): -4.0(1.1), -6.1(1.6), -5.5(1.6), and 3.8(1.4), respectively) and higher free T4 levels (adjusted coefficient (SE): 0.013(0.05), 0.017(0.007), 0.016(0.007), and 0.007(0.006), respectively). These associations were homogeneous in both cohorts, especially for PCBs and total T3 (p-value forthe interaction between cohorts >0.8). Iodine intake and UIC did not affect the association between OCs and thyroid hormones. Our results indicate that exposure to OCs during pregnancy can alter TH levels.

Organochlorine pesticides and polychlorinated biphenyls in fin whales (Balaenoptera physalus) from the Gulf of California

The present study reports unique data on concentrations of several classes of organochlorine pesticides and polychlorinated biphenyls in blubber biopsies from healthy living fin whales (Balaenoptera physalus) from the Gulf of California, Mexico, one of the most isolated and unstudied population in the world. OC levels in this population were generally lower than levels reported in fin whales from other regions. The rank order of OCs were SigmaDDTs (range from 300 to 2400 ng g(-1) lw) > SigmaPCBs (range from 40 to 290 ng g(-1) lw) > SigmaHCHs (range from <LOQ to 92 ng g(-1) lw) > or = SigmaCHLORs (from < LOQ to 100 ng g(-1) lw). The most abundant OC pesticide measured was the DDT metabolite, p,p'-DDE. The PCBs 138, 153, and 180 were the most abundant PCBs congeners found in the fin whales samples. Males had significant higher concentrations of SigmaOC, SigmaDDTs and SigmaPCBs than females (P < 0.05), although the p,p'-DDE/SigmaDDTs ratios were similar between the sexes. Although the OC concentrations found in this population were generally below the levels that would be expected to cause deleterious health effects, the maximum values observed (2700 ng g(-1) lw) in some animals were higher than those associated with reproductive effects in whales. Given the small population size and highly isolated characteristics of Gulf of California fin whales, health effects in individuals could readily translate into population-level effects. Future research on this topic will be necessary to better understand the role that these compounds may have on the health of this population.

Organochlorine pesticide and polychlorinated biphenyl residues in human milk from the Southern Coast of Caspian Sea, Iran

In the present study, human milk was sampled in October 2006 from Nour and Noushahr cities and their countryside on the Southern Coast of Caspian Sea, Iran. They were analyzed for organochlorine pesticides, such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), α, β and γ-hexachlorocycloexane (HCH) isomers and six PCBs congeners (IUPAC Nos. 28, 52, 101, 138, 153 and 180). Average concentrations of HCHs, DDTs, PCBs and HCB were 3780, 2554, 1560 and 930 ng g −1 lipid wt, respectively. There was no significant difference between the concentrations of investigated pollutants between the two cities and their countryside. No significant differences in OCPs and PCBs were found between primiparous and multiparous mothers. There was no correlation between levels of OCPs and PCBs in human milk and the age of mothers. There was a significant difference in the organochlorine levels, including DDTs, between mothers who have eaten fish once a week and those who consumed fish more than once ( p > 0.05). An analysis of the infant exposure to OCPs and PCBs via breast milk indicated that the daily intake rates for most of the mothers were above the guideline proposed by Health Canada which is definitely caused on children health for concern.

Organochlorine Pesticide and Polychlorinated Biphenyl in Calves from North-West Spain

The aim of the present study was to assess the levels of organic pollutants in cattle from the NW of Spain. The livers of 101 animals from two regions (Galicia and Asturias) were analysed for seven organochlorine pesticides (HCB, alpha-HCCH, u-HCCH, HEOD, DDT, TDE) and 34 PCBs congeners (8, 18, 28, 29, 31, 52, 77, 101, 105, 114, 118, 123, 126, 128, 138, 141, 149, 153, 156, 157, 167, 169, 170, 171, 180, 183, 187, 189, 194, 199, 201, 205, 206 and 209). The influence of different factors (type of farm and proximity to industrial areas) on pesticide accumulation in cattle was also studied. Overall, the frequency of occurrence and concentrations of OC pesticides and PCBs was low in calves from both regions. HEOD was detected most frequently and was found in more than half of the calves from each region. PCBs 141 and 153 were the most frequently detected PCB congeners but typically occurred in less than 20% of animals. The exposure of calves to the more abundant contaminants differed significantly between the regions and may be related to past usage patterns. Differences between farms in terms of their livestock management did not have a significant effect on pesticide accumulation by calves. The liver concentrations in calves were below maximum residues levels (RMLs) for human intake and there is no indication of any risk from these contaminants through eating calf liver.

Congener-specific analysis of non-dioxin-like polychlorinated biphenyls in blood collected from 127 elderly residents in Nakagawa Town, Fukuoka Prefecture, Japan

We conducted congener-specific analysis of non-dioxin-like polychlorinated biphenyls (non-dioxin-like PCBs) in blood collected in February 2004 from 127 elderly residents living in Nakagawa Town, Fukuoka Prefecture, Japan. The present study is one of the few studies in which 56 non-dioxin-like PCBs congeners were measured in human blood. Of the 127 elderly residents, 51 were men (mean: 68.1 years) and 76 were women (mean: 68.1 years). Among 197 non-dioxin-like PCB congeners, 56 were identified in the blood of elderly residents. The arithmetic mean total concentrations of 56 non-dioxin-like PCBs congeners in the blood of elderly men and women in Nakagawa Town were 419 (median: 378) and 363 (median: 323) ng g −1 lipid, respectively, and the concentrations were in the range of 172–1102 and 119–1226 ng g −1 lipid, respectively, indicating that the total concentrations in elderly men are significantly higher than those in elderly women. The contamination of non-dioxin-like PCBs in the blood of elderly men and women in Fukuoka Prefecture was found to have decreased compared to past levels. The ratios of hexachlorinated biphenyls (hexaCBs) to the total concentrations of 56 non-dioxin-like PCBs congeners in the blood of elderly men and women were 44.6% and 45.6%, respectively, which was particularly high compared with those of other congeners. 2,2′,4,4′,5,5′-HexaCB (#153) among hexaCBs congeners, the most abundant congener in the blood of elderly men and women, contributed approximately 23.0% and 23.5% to the total concentrations of 56 non-dioxin-like PCBs congeners, respectively. Furthermore, 2,2′,3,4,4′,5′-hexaCB (#138), 2,3,3′,4′,5,6-hexaCB (#163)/2,3,3′,4′,5′,6-hexaCB (#164), 2,2′,3,4,4′,5,5′-heptaCB (#180), and 2,2′,3,4,4′,5,6′-heptaCB (#182)/2,2′,3,4′,5,5′,6-heptaCB (#187) also showed high ratios to the total concentrations of 56 non-dioxin-like PCBs congeners detected in the blood of elderly men and women. A statistical examination of the relationship between the total concentrations of 56 non-dioxin-like PCBs congeners in blood and the age of elderly residents who were over 60 years indicated statistically significant correlations between the total concentrations of these PCBs congeners and the age of elderly women. However, similar correlations were not observed in elderly men. The results of the present study have indicated the current levels of non-dioxin-like PCBs in the blood of elderly men and women in Fukuoka Prefecture, Japan and can be used as baseline data for those over age 60.

Congener-specific analysis of non-dioxin-like polychlorinated biphenyls in blood collected from 195 pregnant women in Sapporo City, Japan

We conducted a congener-specific analysis of non-dioxin-like polychlorinated biphenyls (non-dioxin-like PCBs) in blood collected between July 2002 and July 2004 from 195 pregnant women living in Sapporo City of Hokkaido Prefecture, Japan. The present study is one of the few studies in which full congener concentrations of non-dioxin-like PCBs have been measured in the blood of pregnant women. Of the 195 pregnant women, 101 were primipara (mean: 28.8 years, median: 28.0 years) and 94 were multipara (mean: 32.3 years, median: 33.0 years). Among the 197 non-dioxin-like PCB congeners, 58 congeners were identified in the blood of pregnant women. The arithmetic mean total concentrations of 58 non-dioxin-like PCB congeners in the blood of primiparous and multiparous mothers in Sapporo City were 42.2–329.3 (mean: 114.5, median: 98.6) and 31.5–258.0 (mean: 100.3, median: 91.4) ng g −1 lipid, respectively. The results show that the contamination of non-dioxin-like PCBs in the blood of women has decreased compared to past levels in other domestic areas, in which the subject age was similar to that in this study. The results of the present study indicate that current levels of non-dioxin-like PCBs in the blood of Japanese women and can be used as baseline data for future temporal trends. The sums of the ratios of the concentrations of hexaCBs and heptaCBs to the total concentrations of 58 non-dioxin-like PCB congeners in the blood of primiparous and multiparous mothers were 78.5% and 77.7%, respectively. The hexaCBs ratios in the blood of primiparous and multiparous mothers were 45.4% and 44.7%, respectively. HexaCB-153 among hexaCBs congeners, the most abundant congener in the blood of primiparous and multiparous mothers, contributed approximately 22.0% and 21.8% to the total concentrations of 58 non-dioxin-like PCBs congeners that were measured in the blood, respectively. Among the non-dioxin-like PCB congeners measured in the present study, hexaCB-138, heptaCB-170, heptaCB-180, and heptaCB-182/heptaCB-187 also showed high ratios to total concentrations of 58 non-dioxin-like PCB congeners detected in the blood of primiparous and multiparous mothers. With regard to the relationship between the total concentrations of 58 non-dioxin-like PCB congeners in maternal blood and the number of deliveries or the age of primiparous and multifarious mothers, the total levels of these PCB congeners tended to decreases 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 concentrations of these PCB congeners in blood and the age of primiparae and multiparae. The concentrations of hexaCB-153 in the blood of primiparous and multiparous mothers showed a close correlation to the total concentrations of these PCBs, suggesting that hexaCB-153 could be an indicator of total concentrations of non-dioxin-like PCB congeners in the blood of pregnant women.

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.

Levels of polychlorinated biphenyls residues in Warri River, Nigeria

Sum of individual PCBs congeners in surface water and sediment samples from Warri River system, a coastal river of Niger Delta, Nigeria were measured between March and June 2003. Specific individual PCBs analysis was by HPGC series 6890. Mean concentrations of ΣPCBs in surface water samples ranged from 0.35 μg l -l (Tori Creek) to 1.30 μg l -l (Crawford Creek). Sediment samples had higher levels ranging from 2.00 ng g -l (Tori Creek) to 7.00 ng g -l (Crawford Creek). Null hypothesis of normality was rejected at p>0.05 indicating significant difference between the matrices. Concentrations of PCB were compared with ecotoxicological benchmarks and regulatory guidelines to determine potential concern for effects on aquatic life and human health. Measured mean concentrations in surface water and sediments samples from Crawford creek station indicated concern for environmental and public health because of their exceedence of the US EPA PCB limit for drinking water (0.0005μgl -l ) and water quality criteria for chronic exposure (79pgl -l ) through drinking water and fish ingestion. KEY WORDS: PCBs, Water, Sediment, Hazard, Warri River. Global Journal of Environmental Sciences Vol.4(1) 2005: 65-71