Dietary Exposure to Polychlorinated Biphenyls and Dioxins and Its Relationship to Telomere Length in Subjects Older Than 55 Years from the SUN Project

Exposure to persistent organic pollutants (POPs) may influence telomere length (TL), which is considered as a marker of biological age associated with the risk of chronic disease. We hypothesized that dietary exposure to polychlorinated biphenyls (PCBs) and dioxins could affect TL. Our aim was to evaluate the association of dietary exposure to PCBs and dioxins with TL. In this cross-sectional study of 886 subjects older than 55 y (mean age: 67.7; standard deviation (SD): 6.1; 27% women) from the “Seguimiento Universidad de Navarra” (SUN) project. TL was determined by real-time quantitative polymerase chain reaction and dietary PCBs and dioxins exposure was collected using a validated 136-item Food Frequency Questionnaire. Multivariable linear regression models were used to control for potential confounding factors. Shorter TL was associated with dietary total PCBs (SD of T/S ratio/(ng/day) = −0.30 × 10−7; 95% CI, −0.55 × 10−7 to −0.06 × 10−7), dioxin-like PCBs (DL-PCBs) (SD of T/S ratio/(pg WHO TEQ (Toxic Equivalents)/day) = −6.17 × 10−7; 95% CI, −11.30 × 10−7 to −1.03 × 10−7), and total TEQ exposure (SD of T/S ratio/(pg WHO TEQ/day) = −5.02 × 10−7; 95% CI, −9.44 × 10−7 to −0.61 × 10−7), but not with dioxins (SD of T/S ratio/(pg WHO TEQ/day) = −13.90 × 10−7; 95% CI, −37.70 × 10−7 to 9.79 × 10−7). In this sample of middle-aged and older Spanish adults, dietary exposure to total PCBs and DL-PCBs alone and together with dioxins was associated with shorter TL. Further longitudinal studies, preferably with POPs measured in biological samples, are needed to confirm this finding.

Distribution and Carcinogenicity of PCBs in Soil Contaminated with Transformer Oil in Selected Locations in Jos, Plateau State Nigeria

Soil from the vicinity of transformers installation in different locations in Jos, Plateau State was investigated for Polychlorinated Biphenyls (PCBs). The assessment was carried out for both total PCBs and congeners using Agilent 6975 GC-MS in ten different locations. The soil samples were extracted with 1:1 hexane- acetone in an ultrasonic bath, concentrated and cleaned with column chromatography using silica gel and hexane as eluting solvent. The result shows five locations were polluted with PCBs that exceed the maximum limit of 2.0mg/kg as permitted by the United States Toxic Substance Control Act (TSCA) with the following values NGS 1 (14.25), NGS 3 (4.47), NGS 6 (9.48), NGS 9 (8.21) and NGS 10 (5.05) while the others have NGS 2 (0.64), NGS 4 (1.85), NGS 5 (0.83), NGS 7 (0.95) in mg/kg respectively, NGS 8 value was below the instrument detection limit (0.0012mg/kg). The order for the total PCBs concentration in these selected locations are NGS 1 > NGS 6 > NGS 9 > NGS 10 > NGS 3 > NGS 4 > NGS 7 > NGS 5 > NGS 2. The carcinogenicity of the dioxin-like PCBs calculated as total toxicity equivalence concentration (TTEC) in these selected locations corresponds to NGS 1 (0.00001), NGS 2 (0.0000051), NGS 3 (0.0000054), NGS 4 (0.0000051), NGS 6 (0.0000063), NGS 7 (0.0000078), NGS 9 (0.0000051) and NGS 10 (0.0000051) respectively. The total cancer risk computed by addition of cancer risk due to ingestion, inhalation and dermal contact revealed that all the locations have very low to low cancer risk compared with the value recommended by the United State.

Tissue Distribution and Immunomodulation in Channel Catfish (Ictalurus punctatus) Following Dietary Exposure to Polychlorinated Biphenyl Aroclors and Food Deprivation

Although most countries banned manufacturing of polychlorinated biphenyls (PCBs) over 40 years ago, PCBs remain a global concern for wildlife and human health due to high bioaccumulation and biopersistance. PCB uptake mechanisms have been well studied in many taxa; however, less is known about depuration rates and how post-exposure diet can influence PCB concentrations and immune response in fish and wildlife populations. In a controlled laboratory environment, we investigated the influence of subchronic dietary exposure to two PCB Aroclors and food deprivation on tissue-specific concentrations of total PCBs and PCB homologs and innate immune function in channel catfish (Ictalurus punctatus). Overall, we found that the concentration of total PCBs and PCB homologs measured in whole body, fillet, and liver tissues declined more slowly in food-deprived fish, with slowest depuration observed in the liver. Additionally, fish that were exposed to PCBs had lower plasma cortisol concentrations, reduced phagocytic oxidative burst activity, and lower cytotoxic activity, suggesting that PCBs can influence stress and immune responses. However, for most measures of immune function, the effects of food deprivation had a larger effect on immune response than did PCB exposure. Taken together, these results suggest that short-term dietary exposure to PCBs can increase toxicity of consumable fish tissues for several weeks, and that PCB mixtures modulate immune and stress responses via multiple pathways. These results may inform development of human consumption advisories and can help predict and understand the influence of PCBs on fish health.

Carcinogenicity of dioxin-like polychlorinated biphenyls in transformer soil in vicinity of University of Port Harcourt, Choba, Nigeria

Polychlorinated Biphenyls (PCBs) in the vicinity of transformers soils at main campus of university of Port Harcourt, Choba, Nigeria was monitored. Evaluation was done for both total PCBs (Aroclor) and congener’s form using Gas Chromatography at four designated sites; A, B, C, and D with geographical co-ordinates for site A-Donald Ekong Library, latitude 4°54’, 32’’N and longitude 6°55:05’’E, site B-Senate building with latitude 4°54’14’’N and longitude 6°55’, 23’’N, site C-Transformer close to music department with latitude 4°54’, 01’’N and longitude 6°55; 56’’E and finally site D-Gana-Ma Lecturers residential quarters with latitude 4°54’.23’’ N and longitude 6°55’, 74’’E. All the sites are polluted with PCBs that exceeds the maximum limit of 2.0 mg/kg as per United States Toxic Substances Control Act (TSCA). The order of total PCBs was site D site > site A > site B > site C, which also corresponds with the order of sites carcinogenicity of dioxin-like PCBs, calculated as Total toxicity Equivalence concentration (TTEC). The TTEC for site A, B, C and D corresponds to 0.000012, 0.000035, 0.0000185 and 0.00039 (mg/kg), respectively, which exceeded the method B clean up levels for 2, 3, 7, 8-tetrachloro dibenzo-p-dioxin levels of 1.3×10-5 mg/kg and need of massive cleanup for carcinogenic dioxin-like PCBs. We also found out there is high loadings of PCBs congeners with little or no biodegradability across the four sites. To mitigate the known human health risks posed by PCBs toxicity, non-PCBs transformers should be replaced with current ones and extensive soil remediation is needed to clean up the PCBs to avoid negative impact.

Assessment of the levels of polychlorinated biphenyls in sediments of new Calabar River, Niger Delta Region, Nigeria

The concentrations of polychlorinated biphenyls (PCBs) in sediment samples from the New Calabar River in the Niger Delta Region of Nigeria were determined. Grab sediment samples were collected from five stations in the river and analyzed for individual PCB congeners using gas chromatography - mass spectrometer. The Σ8PCB (sum of eight congeners) identified in the samples ranged from 0.21 to 2.16 mg/kg. Congener 105 and 194 were the most and least abundant with 34.65 % and 2.46 % respectively. The lower chlorinated congeners (below PCB 101) were prominent with 54.68 % of the total PCBs concentration in the sediments. The results of this study should make PCBs contaminants of grave concern in the Niger Delta Region.

Diabetes in Native Americans: elevated risk as a result of exposure to polychlorinated biphenyls (PCBs)

We have studied rates of diabetes in 601 members of the Mohawk Nation at Akwesasne, ages 18–84 years, in relation to serum concentrations of 101 polychlorinated biphenyl (PCB) congeners and three chlorinated pesticides [dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB) and mirex]. Diabetes was determined from either a diagnosis by a physician or by having a fasting glucose concentration of >125 mg/dL. Rates of diabetes are high in this community. Three models were used. In the first model rate ratios (RR) were determined for quartiles of total PCBs after adjustment for age, sex, body mass index (BMI) and total serum lipids. For total PCBs RR=2.21 (1.2–4.2), while for total pesticides RR=3.75 (1.3–10.7). When the total PCB results were also adjusted for total pesticides and the total pesticide results were also adjusted for total PCBs (Model 2) the RRs were somewhat reduced. In Model 3 we considered subgroups of PCBs based on numbers of chlorines on the molecule (tri-/tetra, penta-/hexa, hepta plus) and numbers of

PCBs Removing in Aged Landfill Leachate by an Innovative Biofilm Reactor with Biomass Carriers - Luffa Sponges

PCBs removal in the aged leachate by a new combination process based on an innovative biofilm reactor with natural fiber media, combined coagulation with a two-staged sequencing batch biofilm reactor with Luffa Sponges (LS) as the biomass carriers (LS-SBBR), was studied in this paper. The results indicated that the total PCBs removal in the aged leachate was 51.97%, and the PCBs removals are mainly achieved by the removal of trichlorobiphenyls, the PCBs contents in sludge in the two-staged LS-SBBR were consistent with the conclusion that the PCBs removal in liquid phase of the second LS-SBBR was higher than that of the first LS-SBBR.

Pcbs in Soils around an Old Electric Transformer Factory in North China

The 28 surface soil samples (0-10 cm) were collected from the urban area of Baoding city nearby an old electric transformer factory for analysis of 84 PCB congeners. Total PCBs concentrations ranged from 0.69 to 11.15 ng/g (mean: 3.62 ng/g). The PCBs concentration (5.72 ng/g) for sampling sites in the vicinity (0-2.5 km) of the transformer factory was higher than that (2.96 ng/g) for other sampling sites. Compositional patterns of individual congener and homologs were similar to those of Chinese transformer oils. The top five congeners were PCB-6, 18, 22, 33 and 31/28 among the identified PCBs. Low chlorinated PCBs (di-to tetra-CBs) accounted for 69.58% of total PCBs concentrations and the predominant PCB homologs were tri-CBs (46.38%), penta-CBs (13.73%) and di-CBs (9.47%), respectively. Principal component analysis showed that technical formulations such as Chinese transformer oil, Aroclor1242, 1016, KC-300 and A-30 were the main sources of soils PCBs from Baoding city. The TEQ concentrations based on ten dioxin-like PCBs ranged from 0 to 26.0986 ng/kg with the mean value as 7.3336 ng/kg.

PCBs in Air from an Industrial Zone in a Coastal City-Tianjin, China

The 23 air samples were collected from Tianjin Dongli industrial zone from July 2010 to May 2011 for the analysis of 84 PCB congeners to investigate the gas/particle partitioning. The total PCBs concentration ranged from 71.08 to 567.36 pg m-3 with the mean value as 307.78±137.45 pg m-3 and the seasonal trends were summer >winter >spring >autumn. Gas PCBs accounted for 77.47% of the total PCBs. The fraction of each gas PCB homolog increased with the decreasing chlorine atoms. The contribution of gas PCBs to total PCBs showed a strong seasonal variation with summer (92.44%)> autumn (85.16%) > spring (80.61%) > winter (42.70%). Tri-, tetra-, penta-PCBs and di-PCBs were the predominantly homologs in atmosphere from industrial zone in Tianjin. The natural logarithm of partial pressure of PCBs were well correlated with the inverse absolute environmental temperature (R=0.77). The steep slope of-3764 obtained from Clausius–Clapeyron plot indicated the influence of local PCBs sources.