Non-ortho Polychlorinated Biphenyls Research Articles

Polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, pesticides, and diabetes in the Anniston Community Health Survey follow-up (ACHS II): single exposure and mixture analysis approaches

Dioxins and dioxin-like compounds measurements were added to polychlorinated biphenyls (PCBs) and organochlorine pesticides to expand the exposure profile in a follow-up to the Anniston Community Health Survey (ACHS II, 2014) and to study diabetes associations. Participants of ACHS I (2005–2007) still living within the study area were eligible to participate in ACHS II. Diabetes status (type-2) was determined by a doctor's diagnosis, fasting glucose ≥125 mg/dL, or being on any glycemic control medication. Incident diabetes cases were identified in ACHS II among those who did not have diabetes in ACHS I, using the same criteria. Thirty-five ortho-substituted PCBs, 6 pesticides, 7 polychlorinated dibenzo-p-dioxins (PCDD), 10 furans (PCDF), and 3 non-ortho PCBs were measured in 338 ACHS II participants. Dioxin toxic equivalents (TEQs) were calculated for all dioxin-like compounds. Main analyses used logistic regression models to calculate odds ratios (OR) and 95 % confidence intervals (CI). In models adjusted for age, race, sex, BMI, total lipids, family history of diabetes, and taking lipid lowering medication, the highest ORs for diabetes were observed for PCDD TEQ: 3.61 (95 % CI: 1.04, 12.46), dichloro-diphenyl dichloroethylene (p,p’-DDE): 2.07 (95 % CI 1.08, 3.97), and trans-Nonachlor: 2.55 (95 % CI 0.93, 7.02). The OR for sum 35 PCBs was 1.22 (95 % CI: 0.58–2.57). To complement the main analyses, we used BKMR and g-computation models to evaluate 12 mixture components including 4 TEQs, 2 PCB subsets and 6 pesticides; suggestive positive associations for the joint effect of the mixture analyses resulted in ORs of 1.40 (95% CI: -1.13, 3.93) for BKMR and 1.32 (95% CI: -1.12, 3.76) for g-computation. The mixture analyses provide further support to previously observed associations of trans-Nonachlor, p,p’- DDE, PCDD TEQ and some PCB groups with diabetes.

Seasonal congener survey for polychlorinated biphenyls in sediments of south-western rivers, Nigeria: Occurrence, sources, and ecotoxicological risks

In this work, sediment samples from major rivers within southwestern Nigeria were collected to study the seasonal distribution, transport, and ecological risk assessment of polychlorinated biphenyls (PCB) using gas chromatography coupled with an electron capture detector (GC–ECD). The ΣPCB concentrations ranged from 9.86–77.56 μg/kg and 11.88–80.76 μg/kg in dry and wet seasons respectively. The most predominant PCBs congener in all the sediments was 2,2’,4,5,5’-PeCB(#101) with mean concentrations of 4.35 ± 2.96 and 6.10±3.38μg/kg across all locations in dry and wet seasons respectively. Relevant guidelines including sediments quality guidelines (SQGs) mean effect range-median quotient (m-ERM-Q), and toxic equivalent factor (TEF) were used for risk assessment and to evaluate the ecological risks of PCBs across the rivers. The toxic equivalent quantity (TEQ) ranged from 0.044–0.807 μg-TEQ/kg and 0.055–0.825 μg-TEQ/kg for the dry and wet seasons respectively. The non-ortho PCBs congeners constituted ≥ 99.8% of the ∑TEQ values. The seven indicators PBCs for evaluating non-dioxin-like PCBs ranged from 3.70–32.69 μg/kg across the seasons and accounted for 33.4%, 39.8%, 36.8%, 37.9%, 41.4%, and 40.4% of the ∑PCBs at Asejire, Odo Ona, Ogbese, Ogun, Ikorodu rivers and Third Mainland Bridge Ocean respectively. In two out of six rivers, the ∑PCBs exceeded the Canadian SQG threshold effect level of 21.5 and 34.1μg/kg for fresh and marine sediments respectively. The results of the study call for a concerted effort toward holistic monitoring of PCB residues in rivers in Nigeria to ensure ecological integrity and the protection of human health.

Effect of sorbate stereochemistry on the sorption/desorption of polychlorinated biphenyls between natural soil and an aqueous solution

ABSTRACT This study aimed to investigate the effect of various sorbate physicochemical properties on the transportation, distribution, fate, and bioavailability as well as remediation of selected hydrophobic organic pollutants in the environment. The natural soil collected from uMngeni River of KwaZulu-Natal province of South Africa and non-ortho and ortho-substituted polychlorinated biphenyls (PCBs) were used in this study. Soil physicochemical properties were characterized and batch studies were carried out to determine the co-effects of PCB stereochemistry and concentration. The results indicated that non-ortho compounds (PCB 77) sorbed more to the soil, (approximately 67%) compared to the di-ortho substituted congener (PCB 52) with 59.5% sorption of the same homolog. The effect of initial concentrations of both non-ortho and ortho-substituted PCBs revealed that low initial PCB concentrations were mostly favored for the sorption while sorption was generally low for ortho-substituted PCBs at high concentration. It is noted from this study that the stereochemistry of PCB congeners may play a critical role in influencing the pollution indices in the environment. Therefore, ortho-substituted congeners may likely be susceptible to aqueous solubility and may likely lead to less affinity to sorb to soil/sediment, and if sorbed have potential to re-suspend back to surface water or leach to the groundwater easily thus posing more risk to aquatic organisms.

Association of prenatal exposure to dioxin-like compounds, polychlorinated biphenyl, and methylmercury with event-related brain potentials in school-aged children: The Hokkaido study

Previous studies have indicated that prenatal exposure to dioxin-like compounds (DLC) or polychlorinated biphenyl (PCB) has a negative association with neurodevelopment in school-aged children. Event-related brain potentials (ERP) can reveal subtle and specific differences in the modulation of cognitive processes that are assumed when they are associated with lower levels of prenatal exposure to DLC or PCBs. This prospective birth cohort study was conducted to examine the association between prenatal exposure to relatively low levels of DLC, PCB or methylmercury (MeHg), and ERP. A total of 55 children who were 13 years old participated in a 3-stimulus oddball task to detect P3a and P3b waves. The task required participants to respond to a target among random stimuli at two difficulty levels. The P3a amplitude reflects an automated attention capture process, and P3b reflects a voluntary attention allocation process. We analyzed DLC congeners in blood samples from four groups, including 7 polychlorinated dibenzo-p-dioxins (PCDD), 10 polychlorinated dibenzofuranes (PCDF), 4 non-ortho PCBs, and 8 mono-ortho PCBs. PCB-153 was chosen as an indicator because of its high correlation with the sum of 58 NDL (non-dioxin-like)-PCBs. MeHg exposure level was assessed by the mercury concentration in hair samples (HHg) taken during the perinatal period. The reaction time to the target stimulus during the oddball task shortened with the increasing MeHg exposure level. Furthermore, P3b latency, which reflect response decision and correlates with reaction time, was also shortened with increasing MeHg level in the difficult condition. These results are counterintuitive because shorter reaction times or rapid decision making reflected by P3 latency are generally favorable. This might be due to nutritional factors such as fatty acids, which have beneficial effects on brain development. The P3a amplitude decreased with non- and mono-ortho PCB and HHg levels, regardless of the difficulty level, and with PCDD, PCDF, and total DLC levels, especially in the difficult condition. P3b latency shortened with HHg, and P3b amplitude decreased with mono-ortho PCBs and PCB-153 in both conditions and with PCDD, PCDF, non-ortho PCBs, and total DLC in the difficult condition. In conclusion, we found an association between prenatal exposure to DLC and a decrease in both P3a and P3b amplitude, even when DLC levels were lower than in most previous studies. Additionally, our results suggest that the automated attention capture process reflected by P3a is associated with maternal MeHg exposure and that the voluntary attention allocation process reflected by P3b is associated with PCB-153. However, these results should be interpreted with caution because of the limitations on sample size, population bias, and statistical analyses.

Legacy contaminant-stable isotope-age relationships in Lake Ontario year-class Alewife (Alosa pseudoharengus)

Alewife (Alosa pseudoharengus) are the preferred prey species of the top piscivore predators in the Lake Ontario food web and are an essential constituent in the bioaccumulation of persistent organic contaminants. Year-class samples collected in 2016 represent the alewife age ranges of 2015 (Age-01) sequentially dating back to 2008 (Age-08). The most abundant contaminant measured in Lake Ontario alewife (151.5 ng/g) were total polychlorinated biphenyls (PCBs), increasing at a rate of 11.8 ng/g per year on an age-averaged concentration basis. Total mercury demonstrated the largest percent increase (240%) accumulated over alewife ages of 1–8 years. Average total concentrations of the most abundant polychlorinated dibenzo-p-dioxin isomer (2378-tetrachlorinated dibenzo-p-dioxin (TCDD), 1.3 pg/g) and polychlorinated dibenzofuran isomer (2378-tetrachlorinated dibenzofuran (2378-TCDF), 6.6 pg/g) comprised most of the overall total dioxin (2.5 pg/g) and total furan concentrations (8.7 pg/g). The vast majority (69%) of alewife total toxic equivalence (TEQ) was comprised of the non-ortho coplanar PCBs. Both mammal and avian wildlife protection values based on total TEQ were uniformly exceeded for the dioxin-like compounds measured in Lake Ontario alewife. Ontogenetic dietary influences expressed a significant impact on Age-01 alewife age-contaminant relationships and age-stable isotope concentrations and trends for legacy contaminants. Total Hg and all dioxin-like contaminants did not demonstrate the Age-01 ontogenetic dietary effects found in legacy contaminants. A prominent polychlorinated naphthalene (PCN) concentration peak measured in year-class Age-04 alewife was followed by a corresponding lake trout peak 3–4 years later illustrating a unique example of trophic-level contaminant uptake and concomitant integration delay.

Type II diabetes status, adipokines, and dioxin-like compounds in the Anniston Community Health Survey II

Background/Aim: A polychlorinated biphenyl (PCB) production facility operated in Anniston, AL for several decades. Serum PCB concentrations were found to be about 3 times higher than the general U.S. population, and the Anniston Community Health Survey (ACHS 2005-07) found significant associations between PCBs and type II diabetes (T2D) prevalence. We also noted an inverse relationship between insulin and dioxin-like compounds in a subset of participants where the novel liver damage biomarker – cytokeratin 18 (CK-18) indicated non-alcoholic toxicant-associated steatohepatitis (TASH). Using data on serum concentration of dioxin-like compounds collected in the 2014 follow-up study (ACHS II), we investigated the association between dioxin-like compounds, insulin, measured cytokines, and adipokines as related to T2D status. Methods: T2D status was defined as previous physician diagnosis, measured glucose >125 mg/dL, or being on any glycemic medication; 135 (39.9%) of 338 participants were classified as diabetic. Adipokines were measured on HADK2MAG-61K and HADK1MAG-61K bead arrays (EMD Millipore, Billerica, MA). The polychlorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF), and non-ortho PCBs were measured using high-resolution gas chromatography/high-resolution mass spectrometry and expressed as dioxin toxic equivalents (TEQs, pg/g lipid). Linear regression models adjusted for age, sex, ethnicity, BMI, family history of diabetes, and smoking status.Results/Conclusion: We found significant associations between total dioxin concentration and insulin, leptin, and adiponectin for the total 338 participants. For insulin and leptin, this was primarily driven by PCDD/PCDF TEQ in those with diabetes (β=-0.31, p-value 0.034; β=-0.010, p-value 0.003). For adiponectin, these associations were stronger in those without diabetes (β=0.27, p-value 0.017). Participants with TASH saw a similar inverse relationship between PCDD/PCDF and insulin, and those with both diabetes and TASH had the largest measure of effect (β=-1.08, p-value 0.01). These findings suggest that these chemicals may affect concentrations of compounds regulating glucose levels as well as lipid metabolism and energy balance.

Perinatal dioxin exposure and neurodevelopment of 2-year-old Vietnamese children in the most contaminated area from Agent Orange in Vietnam

Bien Hoa airbase is the most contaminated area of dioxin contamination from Agent Orange in Vietnam, but little is known about the neurodevelopmental effects of perinatal dioxin exposure on children living nearby. We recruited 210 mother–newborn resident pairs in 2012 and 78 pairs in 2015 and followed them for 2 years to assess the children's neurodevelopment. As a control group, we used 120 mother–child pairs recruited in 2014 in the Ha Dong district of Ha Noi City, an unexposed area. Perinatal dioxin exposure levels were indicated by levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and toxic equivalency values of polychlorodibenzodioxins, polychlorodibenzofurans, and nonortho-polychlorinated biphenyls (TEQ-PCDD/Fs/noPCBs) in maternal breast milk. The Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) were used to assess neurodevelopment, and scores in each domain were compared between children with different exposure levels using general linear regression models and stratification by sex. Decreased expressive and composite language scores in boys and gross motor scores in girls were found in children exposed to TCDD ≥ 5.5 (pg/g lipid) compared with children with TCDD < 1.8. However, in matched pair analysis between children with TCDD ≥ 5.5 and <1.8 (pg/g lipid), lower expressive and composite language scores in boys exposed to TCDD ≥ 5.5 were significant, but lower gross motor scores in girls did not reach statistical significance. In addition, significant association was found between levels of PCDD congeners other than TCDD and gross motor scores in boys. These findings suggest that perinatal exposure of TCDD and other PCDD congeners affects development of language and gross motor skills, respectively, in boys at 2 years of age exposed to dioxins originating from Agent Orange in Vietnam.

Are ingested plastics a vector of PCB contamination in northern fulmars from coastal Newfoundland and Labrador?

While marine animals are exposed to environmental contaminants via their prey, because plastic pollution in the aquatic environment can concentrate some chemicals, ingested plastics are thought to increase the exposure of biota to contaminants. Currently, in the literature there are contradictory results relating to how higher levels of ingested plastics by birds may lead to higher levels of polychlorinated biphenyl (PCBs). To date none of these have incorporated known Toxic Equivalency Factors (TEFs) for non-ortho and mono-ortho congeners of PCB which is critical to assessing the potential effects from PCBs. We examined northern fulmars (Fulmarus glacialis) from the Labrador Sea region Canada, and the ingested plastics from these same birds for comparative PCB concentrations. We found no significant correlations between the PCB concentrations in the birds and the mass or number of retained ingested plastic pieces in the stomach, this held true when PCBs were considered by a number of different ways, including ∑4PCB, ∑PCB, lower-chlorinated, high-chlorinated, non-ortho PCB, and mono-ortho congeners. PCB concentrations were lower in plastics as compared with livers. We found significant differences in congener profiles between the ingested plastics and seabird livers suggesting that while plastics do not contribute to the PCB concentrations, there may be some interactions between plastics and the chemicals that the birds are exposed to via ingested plastics.

An effective and low cost carbon based clean-up method for PCDD/Fs and PCBs analysis in food

Sample preparation is of critical importance in dioxin analysis of food and feed samples. It is a complex procedure that includes lipid extraction followed by the application of chromatographic separation techniques, aiming in removing undesirable interferences from the matrix. The separation of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) from polychlorinated biphenyls (PCBs) is achieved by carbon-based materials which should have high fat capacity in order to be suitable for lipid-containing matrices. Automated methods are available but due to high cost and use of high amounts of solvents, manual methods are also applied. An active carbon material (Carbosphere) with high fat capacity that has been used in the past for manual methods is no longer commercially available. The present study assesses an alternative active carbon material, FU 4652, that can be used for the separation of PCDD/Fs and non-ortho PCBs. Mono-ortho and 6 non-dioxin-like PCBs are also analyzed. The method was validated according to the analytical criteria set in EU regulations 589/2014 and 709/2014. Control samples analyzed for the evaluation of the above material were olive oil reference samples spiked with PCDD/Fs and dioxin-like PCBs at two concentration levels. The new method was tested successfully on food samples of interlaboratory trials organized in previous years. Farmed fish samples collected within national surveillance programs for the years 2016–2017 were analyzed with the method developed. The results obtained indicate that the FU 4652 carbon sorbent has high fat capacity and is capable of separating congeners with good recoveries.

Polychlorinated Biphenyl Contamination in Water and Sediment Samples in Upper River Ogun, Lagos State, Nigeria

Polychlorinated biphenyls (PCBs) are a health risk for high trophic level predators and the Stockholm Convention requires measures to reduce or eliminate their release into the environment. The study was conducted an ecological survey on River Ogun, Lagos, Nigeria, quarterly over a period of two years (March 2013-February 2015). Water physicochemistry and the levels of nine PCB congeners were analyzed in water and sediment samples from five river zones: Agboyi, Maidan, Owode Elede, Kara, and Akute. Water physicochemistry showed significant (p<0.05) increases in conductivity, turbidity, temperature, salinity, total dissolved solids, and dissolved oxygen in the dry season compared to rainy season across the zones, while there was an increase in pH, transparency and depth in the rainy season across the zones. Mean temperature in the range of 28.53 -28.95°C, the mean pHranged between 5.58-7.74, mean total dissolved solid ranged between 0.67 -1.69 g/L, mean conductivity ranged between 0.77 mS/cm -0.94 mS/cm, mean salinity ranged between 0.05 -0.42%, mean turbidity ranged between 29.30-30.50NTU, mean Secchi-disc transparency ranged between 2.88-3.16m, mean depth ranged between 3.21-3.65m while meaning dissolved oxygen ranged between 14.54- 22.65mg/L.PCB congeners were analyzed in sediment and water samples. The analyzed categories were the IUPAC numbers: non-ortho PCBs (CBs 8, 18 and 58), mono-ortho PCBs (CBs 87, 128,170 and 195) and dl-PCBs(CBs 206 and 209). The mean concentrations of PCBs in the sediment samples for all zones ranged from 0.000078-0.01μg/kg, while the mean concentrations of PCBs in the water samples for all the sampled zones ranged from 0.00006-0.006mg/L. The total PCBs concentrations in all water samples in this study for the rainy and dry seasons were 0.0296 mg/Land 0.0299 mgL-1, respectively. The hazard quotient (HQ) values for the rainy season ranged from 0.0039 - 0.014 and between 0.0047 - 0.013571 for the dry season. The cancer risk for the rainy season ranged from 3.90 × 10-6 - 9.82 ×10-6, while that of the dry season ranged from 1.57× 10-7 - 3.17 × 10-7. There was no significant difference between the congeners when the samples were subjected to descriptive (mean and standard error) and analysis of variance statistics and P<0.05 was considered to indicate statistical significance. Means were separated using Bonferroni’s multiple comparison tests, p<0.05). PCB concentrations in all the zones were above US EPA limits in surface waters (0.0005 mg/L), which is a cause for environmental concern for River Ogun.

Congener Specific Determination of Polychlorinated Biphenyls (PCBs) in Human Milk

Eighteen congeners Polychlorinated biphenyls (PCBs) congeners were analyzed in 38 human milk samples collected from different ages living in Eastern and Central provinces in Saudi Arabia. The PCB profile was dominated by higher chlorinated congeners. Non-ortho PCB congeners which have the highest Toxic Equivalency Factor (TEF) values were detected in all of individual samples. PCB-81 and PCB-153, the most dominating PCB congeners, which might therefore be used as an indicator for sum PCBs. Toxic Equivalents Factor (TEF) for mono-ortho substituted PCB congeners indicated higher exposure to toxic PCBs in Eastern province rather the Central due to main petroleum industry activities, but estimated daily intakes for both provinces indicate that infants consuFming mother’s milk are not at risk of adverse effects caused by PCBs. Our study builds the first database in Saudi Arabia research of human milk samples.

Polychlorinated dibenzo-p-dioxins, dibenzofurans, and flame retardants in northern gannet (Morus bassanus) eggs from Bonaventure Island, Gulf of St. Lawrence, 1994–2014

Northern gannet (Morus bassanus) eggs from Bonaventure Island, Québec, Canada, were collected to monitor concentrations of contaminants. Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/Fs) and non-ortho polychlorinated biphenyls (PCBs) were measured in eggs from 2004 and 2009, and several brominated and nonbrominated flame retardants (FRs) were measured every 2–5 years in eggs from 1994 to 2014. The sum (Σ) concentrations of PCDDs/Fs were significantly lower in 2009 relative to 2004, but the total toxic equivalent concentrations for PCDDs, PCDFs, and PCBs showed no significant differences (196 ng/kg wet weight (ww) in 2004 and 220 ng/kg ww in 2009). The mean ΣFR concentrations decreased significantly between 1994 and 2014, from 58 ng/g ww to 19 ng/g ww. Hexabromocyclododecane (HBCDD) was the principal nonbrominated FR detected in gannet eggs and ranged from <1.0 ng/g ww to 6.9 ng/g ww. The PCDD/F and nonortho PCB profiles were dominated by 2,3,7,8- tetrachloro-dibenzofuran (2,3,7,8-TCDF; from 26.2 ng/g ww to 34.8 ng/kg ww) and PCB-77 (from 1580 ng/g ww to 2650 ng/kg ww), respectively. Although the values of both ecological tracer stable isotopes of carbon (δ13C) and nitrogen (δ15N) showed differences among the years, no temporal trends were observed, which indicates relatively stable adults' diet and foraging area over this time period. The trends over time in concentrations of the studied contaminants likely reflect a decrease in environmental contamination. The mean 2012 eggshell thickness was 10% lower than the pre-DDT value and corresponded to a year of poor reproductive success.

Declining trends of polychlorinated dibenzo-p-dioxins, dibenzofurans and non-ortho PCBs in Canadian Arctic seabirds

Polychorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (PCBs) such as the non-ortho PCBs (nPCBs) persist in the environment despite international measures to ban their emissions. We determined congener patterns and temporal trends for PCDDs, PCDFs, nPCBs as well as their toxic equivalents (TEQs) in eggs of thick-billed murres (Uria lomvia) and northern fulmars (Fulmarus glacialis) sampled from Prince Leopold Island in the Canadian Arctic between 1975 and 2014. The dominant PCDD congeners were 1,2,3,7,8-PnCDD, 2,3,7,8-TCDD and 1,2,3,6,7,8-HxCDD, and the dominant PCDF congener was 2,3,4,7,8-PnCDF. The nPCB profile was dominated by PCB-126. The TEQ profile in the murre eggs was dominated by nPCB-TEQ whereas in the fulmar eggs, the PCDF-TEQ contribution to ΣTEQ was slightly greater than that of nPCB-TEQ. Concentrations of ΣPCDD, ΣPCDF, ΣnPCB and ΣTEQ declined between 1975 and 2014 in both murre and fulmar eggs. Based on TEQ thresholds in the literature for other species, and taking into account the trend towards declining TEQ levels, it is unlikely that current levels of PCDDs, PCDFs or nPCBs are affecting the reproductive success of thick-billed murres or northern fulmars in the Canadian Arctic.

Detection of Persistent Organic Pollutants in Blood Serum of Electricians and Welders in Latvia

Abstract Persistent organic pollutants (POPs) are chemical substances that persist in the environment, bioaccumulate through the food web, and pose a risk of causing adverse effects to human health and the environment. The aim of the study was to assess the POP (polychlorinated biphenyls (PCBs), polybrominated diphenylethers (PBDEs), DDT and their derivatives) levels in blood serum to identify possible risk group workers. Blood serum samples (116 in total) were collected from two groups of employees — electricians, who can come in contact with PCB-containing transformer and capacitor oil, and welders, who were used as a control group. Sample purification was done by double solid phase extraction. The concentrations of POPs in blood serum were determined by gas chromatography with electron capture detector GC/ECD and recovery controlled by internal standard CB-174. None of the 116 samples contained the full range of tested POPs. However, all samples contained at least one of pesticides, and a marker PCB and mono-ortho PCB. Blood serum samples of 52% of electricians and 97.8% of welders contained non-ortho PCB compared to 84% and 74.7%, respectively, for PBDE’s. The concentrations of 18 detected PCBs, 4 detected PBDEs and 6 chlorinated pesticides and their metabolites varied in wide ranges and the differences in mean values between groups were not statistically significant (p &gt; 0.05). The estimated concentrations of POPs correspond to the lowest levels detected in other countries. Mean concentrations of low-chlorinated marker PCBs were higher in the electrician group, suggesting that the employment sites are contaminated with PCBs, or that employees have contact with PCB-containing items.

Accumulation and temporal changes of PCDD/Fs and dioxin-like PCBs in finless porpoises (Neophocaena asiaeorientalis) from Korean coastal waters: Tracking the effectiveness of regulation

Temporal trend studies are useful to evaluate the effectiveness of regulations on local pollutants. The emission of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs) has been regulated by the Korean government in accordance with the Stockholm Convention. The accumulation and temporal trends of PCDD/Fs and dioxin-like PCBs were investigated in finless porpoises (Neophocaena asiaeorientalis) collected in Korean waters. Median concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs were 1.0, 1.1, 0.1, and 1.8pgTEQ/g lipid weight, respectively, which were lower than threshold values for marine mammals. Age- and sex-dependent accumulation patterns were found for PCDFs and DL-PCBs. Temporal trends in finless porpoises collected between 2003 and 2010 showed significant reduction rates of 57%, 54%, 69%, and 60% for PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs, respectively. Our results suggest that the regulations on dioxin-like contaminants have been effective for marine mammals in Korea.

Cross-sectional Associations between Exposure to Persistent Organic Pollutants and Leukocyte Telomere Length among U.S. Adults in NHANES, 2001-2002.

Background:Exposure to persistent organic pollutants (POPs) such as dioxins, furans, and polychlorinated biphenyls (PCBs) may influence leukocyte telomere length (LTL), a biomarker associated with chronic disease. In vitro research suggests dioxins may bind to the aryl hydrocarbon receptor (AhR) and induce telomerase activity, which elongates LTL. However, few epidemiologic studies have investigated associations between POPs and LTL.Objectives:We examined the association between 18 PCBs, 7 dioxins, and 9 furans and LTL among 1,330 U.S. adults from NHANES 2001–2002.Methods:We created three summed POP metrics based on toxic equivalency factor (TEF), a potency measure including affinity for the AhR: a) non–dioxin-like PCBs (composed of 10 non–dioxin-like PCBs; no AhR affinity and no TEF); b) non-ortho PCBs (composed of 2 non–ortho-substituted PCBs with high TEFs); and c) toxic equivalency (TEQ) (composed of 7 dioxins, 9 furans, 2 non–ortho-substituted PCBs, and 6 mono–ortho-substituted PCBs; weighted by TEF). We tested the association between each metric and LTL using linear regression, adjusting for demographics, blood cell count and distribution, and another metric with a different TEF (i.e., non-ortho PCBs and TEQ adjusted for non–dioxin-like PCBs; non–dioxin-like PCBs adjusted for non-ortho PCBs).Results:In adjusted models, each doubling of serum concentrations of non-ortho PCBs and TEQ was associated with 3.74% (95% CI: 2.10, 5.40) and 5.29% (95% CI: 1.66, 9.05) longer LTLs, respectively. Compared with the lowest quartile, the highest quartile of exposure was associated with 9.16% (95% CI: 2.96, 15.73) and 7.84% (95% CI: –0.53, 16.92) longer LTLs, respectively. Non–dioxin-like PCBs were not associated with LTL.Conclusions:POPs with high TEFs and AhR affinity were associated with longer LTL. Because many dioxin-associated cancers are also associated with longer LTL, these results may provide insight into the mechanisms underlying PCB- and dioxin-related carcinogenesis.Citation:Mitro SD, Birnbaum LS, Needham BL, Zota AR. 2016. Cross-sectional associations between exposure to persistent organic pollutants and leukocyte telomere length among U.S. adults in NHANES, 2001–2002. Environ Health Perspect 124:651–658; http://dx.doi.org/10.1289/ehp.1510187

The exposure of the Croatian population to toxic environmental contaminants – “Dioxin-like” PCBs

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

Cross-Sectional Associations Between Exposure To Persistent Organic Pollutants And Leukocyte Telomere Length Among Us Adults: National Health And Nutrition Examination Survey, 2001-2002

Introduction: Leukocyte telomere length (LTL) is considered a measure of cellular aging and is associated with chronic disease, including cancer. Exposure to environmental chemicals may influence LTL. For example, in vitro research suggests dioxins may elongate telomeres by binding to the aryl hydrocarbon receptor (AhR) and inducing telomerase activity (which regulates LTL). However, few epidemiologic studies have investigated associations between dioxins or polychlorinated biphenyls (PCBs) and LTL. In this analysis, we examined the association between exposure to 19 PCBs and 17 dioxins and LTL among 1,329 US adults from NHANES 2001-2002. Methods: LTL was measured using quantitative polymerase chain reaction relative to standard reference DNA (T/S ratio). We created 3 summary metrics from lipid-adjusted serum measurements of the PCBs and dioxins, grouped by affinity to the AhR (non-dioxin-like PCBs, non-ortho PCBs, and weighted toxic equivalency (TEQ)). We used linear regression models to test the association between each metric and LTL, adjusting for demographic factors, blood biochemistry, and another metric with different AhR affinity (e.g. the TEQ was adjusted for non-dioxin-like PCBs). Results: Non-ortho PCBs and the TEQ were associated with longer LTL in adjusted models (β: 0.062, 95% CI: (0.033, 0.091), p

Concentrations and Toxic Equivalency of Polychlorinated Biphenyls in Polish Wastewater Treatment Plant Effluents.

Wastewater treatment plants (WWTPs) are widely recognized as important sources of toxic contaminants such as polychlorinated biphenyls (PCBs). An example is given in the present paper, where concentrations of 12 dioxin-like PCBs (dl-PCBs) congeners were investigated in effluents from 14 WWTPs of different sizes, using gas chromatography tandem-mass spectrometry. The results obtained demonstrate that the smallest WWTPs are characterized by the highest total dl-PCB concentration of 102.69pg/L, roughly twice those of medium-size and large WWTPs, i.e. 41.14 and 48.29pg/L, respectively. In all cases, the concentrations obtained were generated mostly by increased contributions of PCB-77, PCB-105 and PCB-118 which constituted 48%-59% of the mean dl-PCB concentration. The results also reveal a predominance of mono-ortho over non-ortho PCBs. All three types of WWTP effluent were found to have similar toxic equivalency (TEQ) values, ranging from 0.31 for large to 0.37pg TEQ/L for medium WWTPs.

Anniston community health survey: Follow-up and dioxin analyses (ACHS-II)--methods.

High serum concentrations of polychlorinated biphenyls (PCBs) have been reported previously among residents of Anniston, Alabama, where a PCB production facility was located in the past. As the second of two cross-sectional studies of these Anniston residents, the Anniston Community Health Survey: Follow-Up and Dioxin Analyses (ACHS-II) will yield repeated measurements to be used to evaluate changes over time in ortho-PCB concentrations and selected health indicators in study participants. Dioxins, non-ortho PCBs, other chemicals, heavy metals, and a variety of additional clinical tests not previously measured in the original ACHS cohort will be examined in ACHS-II. The follow-up study also incorporates a questionnaire with extended sections on diet and occupational history for a more comprehensive assessment of possible exposure sources. Data collection for ACHS-II from 359 eligible participants took place in 2014, 7 to 9 years after ACHS.