Polychlorinated Biphenyls Values Research Articles

DETERMINATION OF POLYCHLORINATED BIPHENYLS (PCBs) IN SURFACE WATER IN ONDO STATE NIGERIA

Polychlorinated biphenyl compounds (PCBs) were included to the Stockholm Convention's list of typical persistent organic pollutants on May 22, 2001. (POPs). Humans have produced PCBs, which are pervasive in the environment. They are a concern for people all around the world because of their toxic, bioaccumulative, long-lasting, hydrophobic, and transboundary characteristics. The study's goals included describing how PCBs are distributed in surface water and evaluating how certain physiochemical factors affect PCB concentrations. Five separate Okitipupa locations—OAUSTECH, Igodan, Okunmo, Idepe, and Lebi/Ofe River—had their water samples taken. The overall average concentration of PCBs discovered in the samples taken from five (5) distinct places was determined to be as follows: OAUSTECH (5.720.13), Igodan (5.520.00), Okunmo (3.480.03), Idepe (21.830.02), and Lebi/Ofe (0.160.00), with their combined probability being determined to be 0.001. Twenty-five (25) PCB congeners were examined using a gas chromatography-electron capture detector (GC-ECD). The majority of congeners were below the detection threshold at every site. Total PCB values varied from 0.16 g/L to 21.83 g/L. The correlation between the overall level of polychlorinated biphenyls and the total organic carbon was positive (0.214), but it was weak (PCBs) and pH, positive (0.096) but poor correlation between the electrical conductivity, and a positive (0.220). The levels found in this investigation, with the exception of one area, were obviously lower than the 0.5μg/l level advised by the WHO. The water's concentration of polychlorinated biphenyls (PCBs) is not significantly impacted by the physicochemical characteristics, and the water is safe to use for household purposes.

Spatial characteristics, sources and exposure risk of polychlorinated biphenyls in dusts and soils from an urban environment in the Niger Delta of Nigeria

Chlorinated organic compounds, such as polychlorinated biphenyls (PCBs), are a threat to both humans and the environment because of their toxicity, persistence, and capacity for long-range atmospheric transport. The concentrations of 28 PCB congeners, including 12 dioxin-like and seven indicator PCBs, were investigated in soils, and indoor and outdoor dusts from Port Harcourt city, Nigeria, in order to evaluate the characteristic distribution patterns in these media, their sources, and possible risk. The PCB concentrations varied from 4.59 to 116 ng g−1 for soils, and from 1.80 to 23.0 ng g−1 and 2.73 to 57.4 ng g−1 for indoor and outdoor dusts respectively. The sequence of PCB concentrations in these matrices was soil > outdoor dust > indoor dust. The composition of PCBs in these matrices indicated the prevalence of lower chlorinated PCBs in indoor and outdoor dusts, while the higher chlorinated congeners were dominant in soils. Di-PCBs were the predominant homologues in indoor dusts, while deca-PCBs were the most prevalent homologues in outdoor dusts and soils. The TEQ values of dioxin-like PCBs in 60 % of the soils, 100 % of the indoor dust, and 30 % of the outdoor dust were above the indicative value of 4 pg TEQ g−1 established by the Canadian authority. The hazard index (HI) values for exposure of adults and children to PCBs in these media were mostly greater than one, while the total cancer risk (TCR) values exceeded the acceptable risk value of 10−6, which indicate probable non-carcinogenic and carcinogenic risks resulting from exposure to PCBs in these media. Source analysis for PCBs in these matrices shows that they originated from diverse sources.

First insight into accumulation of characteristics and tissue distribution of PCBs, PBDEs, and other BFRs in the living Indonesian coelacanth (Latimeria menadoensis).

Persistent organic pollutants, including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and other brominated flame retardants, were detected in the liver, muscle, and ovary tissues of the Indonesian coelacanth (Latimeria menadoensis) incidentally caught around Gangga Island, North Sulawesi Province, Indonesia, on November 5, 2014. Concentrations of total PCBs (209 congeners, 300-2600ngg-1 lipid weight) in all tissues showed higher than those of PBDEs (41 congeners, 3.9-6.3ngg-1 lw) and BTBPE (1.1-3.6ngg-1 lw). The tissue-specific PCB and PBDE profiles were likely due to differences in the lipid composition. Toxic equivalent (TEQ) values of dioxin-like PCBs in coelacanth tissues were lower than the benchmark values for early-life fish. However, compared with the data reported for deep-sea fishes in the Pacific and Indian Oceans, the relatively high concentrations of PCBs detected in this study raise concerns regarding Indonesian coelacanth conservation and habitat conditions.

Chiral signatures of polychlorinated biphenyls in serum from e-waste workers and their correlation with hydroxylated metabolites.

Elevated concentrations of polychlorinated biphenyls (PCBs) found in environmental media and biota from typical e-waste dismantling sites have raised concerns regarding their human body burden and potential negative health effects. In the present study, the enantiomeric compositions of three typical chiral congeners (PCB-95, PCB-132, and PCB-149) were measured in 24 serum samples from e-waste workers by using gas chromatography coupled to triple quadrupole tandem mass spectrometry. The mean enantiomer fractions (EFs) of chiral congeners in serum from the workers were 0.655±0.103, 0.679±0.164, and 0.548±0.095 for PCB-95, PCB-132, and PCB-149, respectively. The (+) enantiomers of PCB-95, PCB-132, and PCB-149 were enantioselectively enriched in serum. Significant positive correlations were observed between the EF of the chiral congener PCB-95 and the total concentration of OH-PCBs, suggesting that EF values of chiral PCBs could be used to indicate the extent of biological metabolism. In addition, the EF of PCB-95 in serum samples increased with increasing work duration of the e-waste workers, thus demonstrating the usefulness of EF values of chiral PCBs as tracers of human exposure to PCBs. Because of the enantioselective enrichment of (+) enantiomers of PCB-95, PCB-132, and PCB-149, further studies are needed to explore the metabolism and toxicity of chiral contaminants in humans.

Associations of polychlorinated biphenyls exposure with plasma glucose and diabetes in general Chinese population: The mediating effect of lipid peroxidation

Polychlorinated biphenyls (PCBs) exposure has been related to the abnormal glucose metabolism and the risk of diabetes. However, the joint effects of various PCBs are uncertain and the potential mechanisms remain unclear. Our objectives were to evaluate the associations of serum PCBs with fasting plasma glucose (FPG) and the risk of diabetes among a general Chinese population, and to estimate the mediating effects of oxidative stress in the above associations. Serum levels of seven indicator-PCBs (PCB-28, 52, 101, 118, 138, 153, and 180) and FPG values were determined among 4498 subjects from the Wuhan-Zhuhai cohort. Oxidative DNA damage biomarker (urinary 8-hydroxy-2′-deoxyguanosine, 8-OHdG) and lipid peroxidation biomarker (urinary 8-isoprostane, 8-iso-PGF2α) were also measured. Positive relationships of serum PCBs with FPG values as well as the risk of diabetes were observed. With each 1% increment in the natural log-transformed values of wet weight serum PCBs, FPG levels increased a 0.125% for PCB-52, 0.168% for PCB-118, 0.221% for PCB-138, 0.273% for PCB-153, and 0.379% for ΣPCB (the sum of seven PCBs). The adjusted odds ratios of diabetes associated with wet weight PCBs were 1.186 for PCB-52, 1.373 for PCB-118, 1.635 for PCB-153, and 1.456 for ΣPCB. The seven serum PCBs showed positive overall effect on the risk of diabetes. Elevated PCB-28, PCB-52, PCB-118, PCB-138, PCB-153, and ΣPCB were associated with the increased urinary 8-iso-PGF2α, which was positively related with FPG values. Furthermore, urinary 8-iso-PGF2α partially mediated the positive associations between PCBs and FPG values, with the mediated proportions ranged from 3.20 to 12.93%. In conclusion, our results suggested that serum PCBs were positively related with increased oxidative stress, FPG values, and the risk of diabetes among a general Chinese population. Serum PCBs mixture had positive overall effect on the risk of diabetes. Lipid peroxidation partly mediated the FPG elevation induced by PCB exposure.

Equilibrium passive sampling: A novel approach to determine internal tissue concentrations of hydrophobic organic compounds in biota

Equilibrium passive sampling has been applied in numerous abiotic environmental matrices. This approach was extended to biological material. In this work, a passive equilibrium sampling method for the measurement of HOCs in biota was developed as an innovative alternative because classical exhaustive extraction techniques are time-consuming and error-prone. The newly developed method is based on the well-proven SPME fiber method for sediment. Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were used as model lipophilic organic pollutants. Partition coefficients of PAHs and PCBs between the lugworm tissue and the PDMS sampling phase were determined. Polydimethylsiloxane (PDMS) coated glass fibers were directly inserted in homogenized lugworm tissue and glass fibers were analyzed using gas chromatography coupled to mass spectrometry. The method application on lugworms from tidal sand flats near Wilhelmshaven showed that the mean body residue values of PCBs (4 μg g−1) and PAHs (256 μg g−1) were about five times higher for PCBs and more than 22 times higher for PAHs compared to literature data for the North Sea area. This high level of contamination might be a consequence of the oil processing refinery located in direct proximity to the sampling site. This novel approach of applying the SPME method to biota will make biological monitoring more effective and holistic, because seasonally and area-wide changes in all environmental compartments can be recorded quickly.

Distribution of organochlorine pesticides and polychlorinated biphenyls present in surface sediments of the Sabaki and Tana estuaries, Kenya

Polychlorinated biphenyls (PCBs) and Organochlorine pesticides (OCPs) in the surface sediments of the Sabaki and Tana estuaries were studied to determine distribution as well as their ecological risk. The concentration range of PCBs and OCPs were 0.65-9.29 ng/g dw and 0.47-9.84 ng/g dw, respectively. Sabaki Bridge in the Sabaki River and Tana 4 in the Tana River recorded high levels of both PCBs and OCPs. The calculated values of DDD+DDE/ DDT showed that the presence of DDT from both the rivers is a result of historical input. The ecotoxicological impact of sediment pollution by PCBs and OCPs was assessed using sediment quality guidelines specified by the Canadian Council of Ministers of the Environment. The concentration values for PCB, HCB, Heptachlor epoxide, and Chlordane in this study indicate low ecological risk to sediment dwelling organisms. DDT showed an adverse biological effect to sediment dwelling organisms. As a result, there is a need to establish a programme for monitoring persistent organic pollutants in Kenya, so that any elevation in concentration above the environmental quality standards can be detected and appropriate actions taken to minimize potential adverse effects to the environment and public health.

Exploring the influence of concentration fluctuation and matrix effects on a passive sampler of triolein-embedded cellulose acetate membrane measuring polychlorinated biphenyls in water

A membrane of triolein-embedded cellulose acetate membrane (TECAM), as an integrative passive sampler, was applied to adsorb 28 polychlorinated biphenyls (PCBs) from pure water and sea water in order to probe into the influence of concentration fluctuation and water matrix. The results demonstrated the temporal variations of PCBs concentrations in TECAM followed the first-order kinetics model. The periodic refreshment of solution and matrix effects of sea water significantly prolonged the time that PCBs reached equilibrium stage. The refreshment facilitated the uptake mass in TECAM. On the contrary, the matrix effects of sea water and dissolved organic matter (DOM) declined the PCBs absorption to TECAM. The average logKP values of PCBs in pure water were about 1.2 log unit higher than those in sea water in the experiments that the solution was not refreshed, while the difference of average logKP values narrowed to 0.3 log unit if the PCBs solutions were periodically refreshed. The correlation between logKP and logKOW values fitted the quadratic curve well, which was similar to semi-permeable membrane device (SPMD). The appropriate sampling times (t94%) ranged from 98.8 to 819 h (mean 500 h) for pure water with refreshment, much longer than those in sea water with refreshment (80.1~410 h, mean 189 h). The t94% values in the solution with high DOM content increased significantly, up to 409 h. Furthermore, comparing the twoexperiments that the spiked pure water and sea watersolution were refreshedfrequently, the estimated sampling rates (Rs) in pure water (0.154~2.06 L/day with a mean value of 0.605 L/day) were slightlylower than those in sea water (0.292~3.84 L/day with a mean value of 1.69 L/day). However, the Rs values in sea water with DOM declined sharply to 0.042 L/day. Therefore, concentration fluctuation, matrix effect, and DOM contents of sea water evidently posed significant influence on dynamic parameters of TECAM absorption, which would be screened and probed detailed in future.

Primena čiste tehnologije za uklanjanje PCB iz mineralnih ulja i energetskih transformatora do postizanja veoma niskih vrednosti PCB-a za potrebe remonta i reciklaže

The Republic of Serbia signed and ratified the Stockholm Convention on Persistent Organic Pollutants. Law on ratification of the Stockholm Convention was adopted and actions were defined through the National Implementation Plan and the Action Plan. On their basis Project Proper Management and Final Disposal of Polychlorinated Biphenyls (PCBs) was created. Institute Nikola Tesla (INT) participated in the realization of the project. In the period from 2015 to 2022, 601 tons of PCB oil was successfully decontaminated by the INT mobile plant, i.e. the PCB content was below 50 mg/kg, which classified the power transformers (PT) as non-contaminated [1,2]. If PT becomes waste or in case of necessary repair or oil regeneration, the required limit value is 10 mg/kg. According to data from INT database there are still 2637 PTs containing PCBs in the concentration range of 2 to 50 mg/kg. In this paper application of the environmentally closed INT decontamination technology for achieving low values of PCB in the oil is shown.

Kontaminace příbřežních sedimentárních těles řeky Odry u Bohumína organickými polutanty

The aim of this study is to investigate present-day contamination levels of selected organic pollutants (POPs) in channel side bars and identify their sources. The studied area is located on the Odra River in the north-eastern part of the Czech Republic (at the border between the Czech Republic and Poland), between the city Bohumín and Odra´s confluence with Olše River. Sediment samples were taken directly from the channel side bars and subsequently measured for grain size analysis, concentrations of total organic carbon (TOC), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and specific biomarkers (terpenoids). Three main facies were recognized in channel side bars. Grain-size analysis showed the predominance of silt fraction, followed by variable sand contents, whereas the contents of clay fraction were almost stable. No statistically significant correlation was found between grain size and the concentrations of POPs except a weak correlation between PAHs, PCBs and sand fraction. POPs including PAHs, PCBs and OCPs showed high variability. In all samples, the sum of PAHs (maximumvalue of 78.1 mg kg-1) greatly exceeded the Czech preventive limit for dry soil. The sources of PAHs were analysed by employing diagnostic ratios and plots of specific PAH compounds. The results showed a high degree of correspondence suggesting a petrogenic origin associated with direct input into the river system. Relatively high concentrations of PAHs are a consequence of the vicinity of the pollution source and location in natural river reach enabling sedimentation of polluted sediments. Concentrations of PCB, hexachlorobenzene and DDT metabolites were almost insignificant in most of the samples, except for several samples having higher PCB values (maximum value of 47.6 μg kg-1). Specific biomarker compounds were used as an indicator of the presence of fossil matter, and H29 17α(H),21β(H) hopane showed the highest concentrations. The homohopane index indicated petroleum and vehicle exhausts origin. TOC revealed a positive correlation with specific biomarkers (homo hopanes and 16 α(H)- phyllocladane, hexachlorbenzene and PCB.

Assessment of binding potencies of polychlorinated biphenyls and polybrominated diphenyl ethers with Baikal seal and mouse constitutive androstane receptors: Comparisons across species and congeners

The present study evaluated the binding potencies (equilibrium dissociation constant: KD) of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) with the constitutive androstane receptor (CAR)_ligand binding domain (LBD) of the Baikal seal (bsCAR_LBD) and mouse (mCAR_LBD) using a surface plasmon resonance (SPR) biosensor. The binding affinities of individual congeners with mCAR_LBD tended to be higher than those with bsCAR_LBD but the differences were within the same order of magnitude. Notably, PBDE congeners showed higher binding affinities for both CAR_LBDs than PCB congeners. In silico docking simulations demonstrated that PBDEs had more non-covalent interactions with specific amino acid residues in both CAR_LBDs than PCBs, supporting the results of their binding affinities. Binding affinity comparisons among congeners revealed the structural requirements for higher binding; mono or di ortho-, tri meta-, and di para‑chlorine substitutions for PCBs, and di or tri ortho-, mono meta-, and di para‑bromine substitutions for PBDEs. The binding potencies of these congeners unlikely accounted for their previously reported CAR-mediated transactivation potencies, implying that their transactivation is regulated in a ligand-dependent, but a distinct manner from ligand binding. Risk assessment analysis showed that the KD values of individual PCB and PBDE congeners were 1-4 orders of magnitude higher than their respective hepatic concentrations in wild Baikal seal population.

Polychlorinated Biphenyls in Imported Fish

Polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) which have been described as organohalogenic and legacy contaminants that are hazardous to both wildlife and man. The paucity of ecotoxicological data on the PCB content in commercially important fish in Benin Metropolis, Nigeria, warranted this research. In this stead, the PCB profile in the Atlantic Herring (Clupea harengus, Family: Clupeidae, mean length=31.59 cm; Mean weight=274.98 g) marketed in Benin Metropolis, was determined via Gas Chromatographic technique in order to evaluate its suitability for human consumption and to provide baseline data for this contaminant in commercially important fish species. The summary statistics for the mean concentrations of detectable PCBs in C. harengus ranged from 0.019 mg/kg (PCB 118, 156) to 0.434 mg/kg (PCB 126), with a total of 0.581 mg/kg (w/w) while the mean concentrations of PCBs in C. harengus by market ranged from 0.012 mg/kg (PCB 118) at Santana market to 0.526 mg/kg (PCB 126) at New Benin market with no observed significant difference (p>0.05) in the mean concentrations of PCBs in fish between markets. The toxicity quotient (TQ) values for PCBs in C. harengus ranged from 0.0095 (PCB 118, 156) to 0.217(PCB 126) while the estimated daily intake (EDI) values in mg/person/day for PCBs ranged from 0.00076 (PCB 118, 156) to 0.017 (PCB 126). A toxic equivalency (TEQ) value of 0.04342 while the total PCB content in C. harengus according to market ranged from 0.469 mg/kg (Santana market) to 0.658 mg/kg (Uselu market). The total toxicity of mixtures (TTM) index was 0.291. The PCB levels in fish decreased below International threshold values suggesting suitability for human consumption. Continous monitoring of this fish species for toxic concentrations of PCBs was proferred.

PAHs, PCBs and organochlorine pesticides in the atmosphere of Eastern Mediterranean: Investigation of their occurrence, sources and gas-particle partitioning in relation to air mass transport pathways

Thirty-four air samples were collected from 2013 to 2015, at a semi-rural site in Eastern Mediterranean (Island of Crete), to study the atmospheric occurrence of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in the gas and particulate phase. Average levels (gaseous and particulate phase) of PAHs (36 compounds, 11–18 ng/m3), PCBs (49 congeners, 77–93 pg/m3) and OCPs (23 substances, 77–140 pg/m3) were comparable to those reported for similar locations worldwide. Multiple-linear regression analysis, performed to relate atmospheric concentrations with meteorological conditions, revealed as main controlling factors local sources for PAHs and long-range transport (LRT) for PCBs and OCPs. The consideration of parent-metabolite ratios for most OCPs excluded fresh inputs. The application of the potential source contribution function (PSCF) identified Black Sea and eastern Balkans as likely sources for PCBs and OCPs. Significant linear correlations (R2 = 0.79–0.98) were determined between the partitioning coefficients (logKp) and partial vapor pressures (logPL0) for most air samples for PAHs and PCBs excepting OCPs. Slope mr values were close to −1 for PAHs and OCPs indicating gas/particle partitioning close to equilibrium. The corresponding mr values for PCBs were shallower (<-0.60) denoting non-equilibrium conditions and potential sampling artefacts. The octanol-air partition coefficient absorption model, logKp-logKoa, did not offer robust evidence for the evaluation of the atmospheric partitioning of the studied compounds. Experimentally determined particle fractions (ϕ) fitted better with the typical remote and rural curves as predicted by the Junge-Pankow model for most PAHs and PCBs but not for OCPs. The Koa-fom absorptive model could not adequately simulate the measured ϕ values for the majority of the compounds.

Residual Levels of Polychlorinated biphenyls (PCBs) in the Atlantic Mackerel (Scomber scombrus, Linnaeus, 1758) Marketed within a Niger Delta Community

The residual levels of polychlorinated biphenyls (PCBs) in the Atlantic Mackerel, Scomber scrombrus (mean length 44.87 cm, mean weight 478.35 g) marketed in Asaba, Delta State, Nigeria, were determined by Gas Chromatographic (GC) technique in order to ascertain its suitability for human consumption. The summary statistics for the mean concentrations of detectable PCBs in S. scrombrus ranged from 0.04 mg/kg (PCB 153) to 0.65 mg/kg (PCB 126), with a total of 0.93 mg/kg while the mean concentrations of PCBs in S. scrombrus by market ranged from 0.02 mg/kg (PCB 153) at Cable market to 0.82 mg/kg (PCB 126) at Abraka market with no observed significant difference (p&gt;0.05) in the mean concentrations of PCB 153 and PCB 169 in fish between markets. The toxicity quotient (TQ) values for PCBs in S. scrombrus ranged from 0.02 (PCB 153) to 0.33(PCB 126) while the estimated daily intake (EDI) values in mg/person/day for PCBs ranged from 0.00072 (PCB 138) to 0.026 (PCB 126). A toxic equivalency (TEQ) value of 0.0656 was recorded with PCB 126 having the highest Sub-TEQ value of 0.065 while the total PCB content in S. scrombrus according to market ranged from 0.67 mg/kg (Cable market) to 1.20 mg/kg (Abraka market). The observed PCB levels in fish fell below International threshold values indicating suitability for human consumption. However constant monitoring of this aquatic species for hazardous levels of PCBs was highly recommended.

Blood mercury and plasma polychlorinated biphenyls concentrations in pregnant Inuit women from Nunavik: Temporal trends, 1992–2017

The Inuit of Nunavik (Northern Quebec, Canada) are exposed to polychlorinated biphenyls (PCBs) and mercury (Hg) through their consumption of marine country foods. A temporal trend study was initiated in 1992 to monitor circulating levels of PCBs and Hg in pregnant Inuit women, since the fetus is most at risk of adverse health effects. We set out (1) to describe temporal trends of PCBs and Hg levels in pregnant Nunavik women between 1992 and 2017; (2) to determine the prevalence of participants exceeding the guidance values in 2017; (3) to investigate relations between marine country food intake and contaminant levels over the study period. A total of 559 pregnant women provided a blood sample for contaminant analysis from 1992 to 2017. PCB congeners were quantified in plasma (serum) by gas chromatography (GC) coupled to electron capture detection or mass spectrometry (MS). We determined whole blood mercury concentration by cold vapor atomic absorption or inductively-coupled plasma MS. We performed multilevel modeling to assess temporal trends in contaminant levels and relations with marine country food consumption. Concentrations of total PCBs and Hg decreased by 84% and 65% between 1992 and 2017, respectively. Nevertheless, 10% and 22% of women in 2017 exceeded guidance values for PCBs and Hg, respectively. While the decline in marine country food intake is the only factor associated with decreasing Hg levels, other factors may explain the decline in PCB levels. Despite the significant decline in PCBs and Hg levels from 1992 to 2017, exposure to these contaminants is still quite prevalent among pregnant Nunavik women. Most of the decline in Hg exposure is likely due to a shift away from marine country foods to store-bought foods, which is a concern given the cultural and nutritional importance of country foods and the high food insecurity that prevails in Nunavik.

Polychlorinated biphenyls (PCB) and organochlorine pesticides (OCP) in blood plasma - Results of the German environmental survey for children and adolescents 2014-2017 (GerES V).

The German Environmental Survey for Children and Adolescents 2014-2017 (GerES V) investigated the current internal exposure to polychlorinated biphenyls (PCB) and organochlorine pesticides (OCP). These analyses were carried out for a population-representative sub-sample of 1135 children and adolescents (aged 3-17 years) of all 2394 GerES V participants. Blood plasma samples were analyzed for seven indicator PCB (PCB 28, PCB 52, PCB 101, PCB 118, PCB 138, PCB 153 and PCB 180) and selected OCP (hexachlorobenzene, three hexachlorocyclohexane isomers, 4,4'-DDT, 4,4'-DDD and 4,4'-DDE). Despite risk mitigation measures and bans put into force some decades ago children and adolescents living in Germany are still exposed to PCB and OCP: Highest geometric mean plasma concentrations were measured for 4,4'-DDE (0.158μg/L), followed by PCB 138 (0.049μg/L), PCB 153 (0.066μg/L) and PCB 180 (0.032μg/L). Different application patterns of compounds between former East and former West Germany are still reflected by differences in plasma concentrations. Significant differences between age groups and by sexes were found. Moreover, the influence of breastfeeding and fish consumption, which was also found in other studies, was confirmed. Comparison with the results of GerES 2003-2006 confirms a decreasing trend in blood samples observed world-wide. Currently, health-based guidance values for PCB are still exceeded, though to a very limited extent. Also, the widespread occurrence of these compounds underlines the need for further monitoring of these compounds in humans although they are no longer marketed.

Assessment of the spatial distribution of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in urban soil of China.

Long-term (2004-2018) persistent organic pollutants (POPs) data were collected for urban soils of China. The dataset included concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in soils, comprising a range of different compounds. Understanding the source of OCP and PCB pollution is an important step in controlling and reducing pollution levels in the environment. This study aimed to analyze the spatio-temporal distribution, pollution sources, and potential health risks of OCPs and PCBs in urban soils in different regions of China. It was found that the total OCP concentrations ranged from 7.6 to 37331μg/kg with a mean value of 2861μg/kg, and PCBs concentrations ranged from 0.3 to 123467μg/kg with a mean value of 4984μg/kg. The highest OCP concentrations were observed in Beijing and Hebei, whereas the highest PCB concentrations were found in the Zhejiang province. The geographical distribution showed that the total mean concentration of POPs of urban soil was much higher in East China than in West China. According to the isomer ratios, about 64% of provinces and cities showed new sources of dichlorodiphenyltrichloroethane (DDT) input and dicofol input was found in 30% of China. Hexachlorocyclohexane (HCH) in urban soils was mainly derived from fresh usage of lindane (γ-HCH) in most regions of China. Lifetime carcinogenic and non-carcinogenic risks of OCPs and PCBs through ingestion, inhalation, and dermal contact indicated that PCBs in urban soils of China often exceeded safe levels. The total lifetime carcinogenic risk values of PCBs were higher than the individual lifetime acceptable risk level (10-4) in 64% of the studied regions and the non-carcinogenic risk values exceeded the target risk level (10-1) in 53% of the regions. The improved knowledge of the distribution and main pollution sources of POPs in urban soil of China as a result of this study can contribute to better decision-making support for soil pollution control and monitoring.

Prediction of octanol-air partition coefficients for PCBs at different ambient temperatures based on the solvation free energy and the dimer ratio.

Temperature-dependent octanol-air partition coefficients (KOA) are of great importance in assessing the environmental behavior and fate of persistent organic pollutants including polychlorinated biphenyls (PCBs). Due to the tremendous amounts of time, effort and cost needed for the experimental determination of KOA, it is desirable to develop a rapid and precise predictive method to estimate KOA just based on molecular structure. In the present study, a predictive model for log KOA of PCBs at ambient temperatures was developed based on the thermodynamic relationship between KOA and the solvation free energy from air to octanol (ΔGOA). For the calculation of ΔGOA of PCBs, the optimal combination of theoretical method and basis-set was identified to be HF/MIDI!6D for both geometry optimization and energy calculation. Dimer formation could affect the partition behavior and promote the apparent KOA values of PCBs. After taking the effect of dimer formation into account, the goodness-of-fit, predictive ability, and robustness of the predictive model were significantly improved. Apparent log KOA values of PCBs at different ambient temperatures ranging from 283.15 to 303.15 K were predicted. Compared with other reported models, the model developed in the present study had not only comparable goodness-of-fit and predictive ability, but also a universal application domain and the relative independency of experimental data. Therefore, the solvation free energy method could be a promising method for the prediction of KOA.

Polychlorinated Biphenyls (PCBs) Concentration Levels in Human Gallbladder Stones and Gallbladder Tissues in Jordan

The concentration levels of 12 polychlorinated biphenyl (PCB) congeners in human gallbladder tissue and gallbladder stone samples gathered from patients in the Jordan University Hospital were measured. The total mean concentration of PCBs in gallbladder tissues samples was 491.36 µg/kg wet weight. The total mean concentration of PCBs in gallbladder stone samples was 504.03 µg/kg. Pentachlorobiphenyls were predominant PCB congeners, accounting for 23.85% of the total PCB concentration found in gallbladder tissue samples and 25.48% in gallbladder stone samples which represent the most toxic compound between all congeners dioxin-like PCBs. The TEQ values for PCBs in all samples were found in the range of (0.0001–11.72) µg TEQ/kg for gallbladder tissue samples and (0.00–12.84) µg TEQ/kg for gallbladder stone samples. The distribution coefficients of PCBs were calculated between gallbladder stones and gallbladder tissues in each sample. Kd (Cstone/Ctissue) values for PCBs were found in the range 0.22–3.18. The variations in Kd were found to be dependent mainly on type of gallbladder stone and obesity of patient. The results of this study show that both gallbladder stones and gallbladder tissues can be used to assess levels of background contamination especially if the stone was of pure cholesterol type (lipophilicity of the stones). Also a correlation between PCB concentrations and dysplasia in few samples implied that PCBs could be a potential contribution factor to gallbladder tissue mutations. This needs to be generalized by an extensive future study on representative number of gallbladder tissues with dysplasia.

Contamination pathways of polychlorinated biphenyls (PCBs) - From the worker to the family.

The improper recycling of old industrial sized capacitors and transformers in Dortmund, Germany, led to a contamination of workers and environment with polychlorinated biphenyls (PCBs). In 2010, a surveillance program was conducted for the former workers, their relatives, and residents next to the recycling company. In the human biomonitoring, elevated values for PCBs were detected in a proportion of the in-house relatives of the workers, including children. The aim of this study was to reconstruct the contamination pathways from the company to the family. Brought home working clothes of the former employees were identified as a first pathway for a contamination of the residential environment. Those clothes were cleaned at home, due to temporary employment contract. Washing machines and dryers were in consequence highly contaminated with PCBs. This led to a contamination of the relative's clothes and by this to a dermal uptake of PCBs. Another exposure pathway was the inhalation of PCB containing dust. In particular at locations, that were in contact with the working boots, high levels of PCBs were detected in the ambient monitoring. This established another exposure pathway by inhalation of PCB containing dust. The link between the residential influence factors and the PCB plasma concentration (n = 54) is shown by rank correlation. In conclusion, it should be avoided to take home potentially contaminated working clothes or boots, to prevent an exposure of children and other family members.