TY - JOUR. T1 - Improved separation of the 209 polychlorinated biphenyl congeners using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry. AU - Focant, Jean François. AU - Sjödin, Andreas. AU - Patterson, Donald G.. N1 - Funding Information: J.-F. Focant is financially supported by the Oak Ridge Institute for Science and Education (ORISE), a Department of Energy (DOE) facility managed by Oak Ridge Associated Universities (ORAU). PY - 2004/6/25. Y1 - 2004/6/25. N2 - The separation of the 209 polychlorinated biphenyl (PCB) congeners has been studied using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS). Four column combinations based on thermally stable phases, DB-1/HT-8, DB-XLB/HT-8, DB-XLB/BPX-50, and HT-8/BPX-50, have been investigated. The HT-8/BPX-50 set produced the best separation. The distribution of the 100 to 150 ms wide peaks was highly structured in the chromatographic space and based on the ...

The addition of the dioxin-like polychlorinated biphenyl (PCB) congeners to the assessment of risk associated with the 2,3,7,8-chlorine substituted dioxins and furans has dramatically increased the number of laboratories worldwide that are developing analytical procedures for their detection and quantitation. Most of these procedures are based on established sample preparation and analytical techniques employing high resolution gas chromatography/ high resolution mass spectrometry (HRGC/HRMS), which are used for the analyses of dioxin/furans at low parts-per-trillion (ppt) levels. A significant and widespread problem that arises when using these sample preparation procedures for the analysis of coplanar PCBs is the presence of background levels of these congeners. Industrial processes, urban incineration, leaking electrical transformers, hazardous waste accidents, and improper waste disposal practices have released appreciable quantities of PCBs into the environment. This contamination has ...

Polychlorinated dioxins, dibenzofurans (PCDD/PCDF) and polychlorinated biphenyls (PCBs), are persistent organic pollutants (POPs) that bioaccumulate in lipids and may enter the food chain through animal products. Recently, Polish authorities discovered a free range farm whose eggs exceeded national standards for dioxin contamination two-fold. Piskorska-Pliszczynska et al.1 evaluated samples from that farm to determine the likely source of the dioxin exposure and to quantify the bioaccumulation of PCDD/Fs and PCBs in the tissues and eggs of the affected hens. They took specimens from the commercial feed and the soil of the free range areas. A veterinarian also performed necropsies and sampled muscle, abdominal fat, liver tissue, ovarian follicles, and whole eggs present in the oviducts. The researchers identified 35 PCDD/F and PCB congeners of interest, including dioxin-like polychlorinated biphenyls (DL-PCBs) and non-dioxin-like polychlorinated biphenyls (NDL-PCBs), using gas chromatography ...

Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs) are widespread in aquatic systems. These toxicants bioaccumulate in the tissues of aquatic organisms, especially fish as they occupy a position near the top of the aquatic food web. Teleost fish respond to stressors, including toxicants, by activating a co-ordinated network of adaptive responses, collectively termed the integrated stress response, which allows animals to regain homeostasis. Depending on the nature of the stressor, this stress response may be a generalised endocrine response that occurs at the organismal level and/or a cellular response involving protein synthesis. The cellular response to PCB insult involves aryl hydrocarbon receptor (AhR) activation and the induction of biotransformation enzymes, including cytochrome P4501A (Cyp1A). However, little is known about the mode of action of PCBs in affecting the adaptive stress response in animals. The objective of this thesis was to investigate the role ...

Polychlorinated biphenyls (PCB) are persistent environmental chemicals that are known thyroid hormone disrupters. Frequently the disruption of one endocrine axis and the timing of the disruption have an impact on other interdependent hormonal responses. Although the mechanisms for the interdependency of thyroid hormones and leptin have not been fully characterized, both are linked to development and regulation of metabolism. Furthermore, PCB accumulation in depot fat could potentially alter leptin production. In the present study 15-and 30-day-old Sprague-Dawley rats were exposed gestationally and lactationally to 1.25 ppm of Aroclor 1254®, a mixture of 52 PCB congeners, via maternal diet, to determine the effect on leptin and thyroid hormones. Additionally, young adult female rats were fed 1.25 PCB for 21 days and the same hormones were assessed. Serum leptin concentrations were determined by a sensitive murine leptin ELISA (DSL, Inc., Webster, TX). Serum thyroid hormone levels were determined ...

TY - JOUR. T1 - Neurodevelopmental toxicity of prenatal polychlorinated biphenyls (PCBs) by chemical structure and activity. T2 - A birth cohort study. AU - Park, Hye Youn. AU - Hertz-Picciotto, Irva. AU - Sovcikova, Eva. AU - Kocan, Anton. AU - Drobna, Beata. AU - Trnovec, Tomas. PY - 2010. Y1 - 2010. N2 - Background: Polychlorinated biphenyls (PCBs) are ubiquitous environmental toxins. Although there is growing evidence to support an association between PCBs and deficits of neurodevelopment, the specific mechanisms are not well understood. The potentially different roles of specific PCB groups defined by chemical structures or hormonal activities e.g., dioxin-like, non-dioxin like, or anti-estrogenic PCBs, remain unclear. Our objective was to examine the association between prenatal exposure to defined subsets of PCBs and neurodevelopment in a cohort of infants in eastern Slovakia enrolled at birth in 2002-2004. Methods: Maternal and cord serum samples were collected at delivery, and analyzed ...

Article Congener-specific analysis of polychlorinated biphenyl in human blood from Japanese. Polychlorinated biphenyl (PCB) congeners were analyzed by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) of whole blood sam...

TY - THES. T1 - Thyroid hormone binding proteins as novel targets for hydroxylated polyhalogenated aromatic hydrocarbons (PHAHs) : possible implications for toxicity. AU - Lans, M.C.. N1 - WU thesis 1990 Proefschrift Wageningen. PY - 1995. Y1 - 1995. N2 - Some toxic effects caused by polyhalogenated aromatic hydrocarbons (PHAHs) develop through alterations in the reproductive and thyroid hormone regulatory systems, thereby affecting (brain) development, reproduction and behaviour of several species (Stone, 1995, Birnbaum, 1994, for review: Brouwer et al. , 1995, Peterson et al. , 1993). In this thesis we have focused on the effects of different classes of PHAHs, eg. polychlorinated biphenyls (PCBs), dibenzofurans (PCDFs) and dibenzo- p -dioxins (PCDDs) and their hydroxylated metabolites on thyroid hormone homeostasis. These changes seem to be partly caused by Ah-receptor mediated changes in thyroid hormone glucuronidation, and effects on the thyroid gland affecting hormone production and ...

Sediments from the Mersey Estuary were analysed for polycylic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Total PAH concentrations ranged from 626 to 3766 μg/kg and total PCB concentrations ranged from 36 to 1409 μg/kg. These concentrations are intermediate in comparison to other U.K estuaries with similar histories of industrialisation and urbanisation. The distribution of individual PAHs were consistent throughout the Mersey Estuary, this together with molecular indices suggests mainly pyrolitic inputs, augmented by a variety of industrial petrogenic sources. Comparison of tri-to-hepta PCB congeners revealed multiple sources and inputs throughout the estuary. A sediment core collected in close proximity to Garston Docks revealed the take-off, peak pollutant input and recent decline of PCB pollution. However, a second depth profile of sediments at Ellesmere Port showed little change in total or individual PCB concentrations due to extensive sediment reworking and ...

Polychlorinated biphenyls (often shortened to PCBs) are organic chemical compounds that contain chlorine atoms. They were used in industrial chemistry, and to make certain transformers, capacitors, and cooling fluids. The Stockholm Convention on Persistent Organic Pollutants declared them to be among the worst chemical pollutants. Their use has been banned worldwide, since 2001. The mode of action of these substances is similar to that of dioxin. Polychlorinated biphenyls were widely used, and they can be found in the atmosphere, the soil, and the bodies of water anywhere on the earth. In the short term, these substances are not very toxic, but they accumulate in the body. They are teratogens, and may cause cancer. ...

TY - JOUR. T1 - Polychlorinated biphenyls disturb differentiation of normal human neural progenitor cells. T2 - Clue for involvement of thyroid hormone receptors. AU - Fritsche, Ellen. AU - Cline, Jason E.. AU - Nguyen, Ngoc Ha. AU - Scanlan, Thomas S.. AU - Abel, Josef. PY - 2005/7. Y1 - 2005/7. N2 - Polychlorinated biphenyls (PCBs) are ubiquitous environmental chemicals that accumulate in adipose tissues over the food chain. Epidemiologic studies have indicated that PCBs influence brain development. Children who are exposed to PCBs during development suffer from neuropsychologic deficits such as a lower full-scale IQ (intelligence quotient), reduced visual recognition memory, and attention and motor deficits. The mechanisms leading to these effects are not fully understood. It has been speculated that PCBs may affect brain development by interfering with thyroid hormone (TH) signaling. Because most of the data are from animal studies, we established a model using primary normal human neural ...

PCBs are industrial chemicals that have neurotoxic effects, and studies indicate that they interfere with normal functions of the endocrine system. Although the manufacturing of PCBs was banned in the 1970s, they remain a major contaminant of the environment and of human tissues. Epidemiological studies show that exposure to PCBs during intrauterine development is highly associated with measurable neurological deficits in the offspring. In addition, deficits associated with PCBs are inversely associated with maternal thyroid hormone (TH) levels. This suggests that PCBs interfere with TH action in the fetal brain. Using in situ hybridization to measure HES-1 and HES-5 mRNA (direct markers of Notch activity), our laboratory has found that both maternal thyroid status and maternal exposure to PCBs influences Notch signaling in the fetal rat brain. We found that Aroclor 1254 produces a dose-dependent increase in HES-1 expression in the ventricular zone. Recent evidence suggests that Notch signaling ...

TY - JOUR. T1 - Polychlorinated biphenyls promote 1-nitropyrene-induced lung tumorigenesis without the induction of K-ras gene mutation in A/J mice. AU - Nakanishi, Yoichi. AU - Bai, Feng. AU - Inoue, Koji. AU - Takayama, Koichi. AU - Pei, Xin Hai. AU - Harada, Taishi. AU - Izumi, Miiru. AU - Kimotsuki, Kanehito. AU - Tokiwa, Hiroshi. AU - Hara, Nobuyuki. PY - 2001. Y1 - 2001. N2 - Although the effects of polychlorinated biphenyls (PCBs) on human lung carcinogenesis are suggested from the massive PCBs poisoning that occurred in Japan designated Yusho, the detailed molecular mechanism are unknown. 1 nitropyrene (1-NP), an ubiquitous and abundant environmental pollutant, is known to be detected in lung tissues derived from patients with lung cancer in Japan, and its relation to lung carcinogenesis is also suggested. We investigated the effects of PCBs (Kanechlor-400) on l-NP-induced lung tumorigenesis in A/J mice. PCBs were administered intraperitoneally followed by ip injection of 1-NP. The ...

Aquatic organisms passively accumulate hydrophobic organic compounds, such as polychlorinated biphenyls, even when ambient water concentrations of the contaminant are below analytical detection limits. However, contaminant concentrations in tissue samples are subject to an inherently high level of variability due to differences in species, life stage, and gender bioconcentration potentials. Semipermeable membrane devices (SPMDs) were used to sample Aroclor 1254, a mixture of readily bioconcentrated polychlorinated biphenyls (PCBs), in a contaminated wetland near Flat Top, WV. The devices consisted of triolein, a lipid found in fish, enclosed in a polyethylene membrane. SPMDs were deployed in the water column and in direct contact with wetland sediments along a previously identified concentration gradient of PCBs. The devices were retrieved after a 25-day exposure period. Analytes were recovered by dialyzing the devices in nanograde hexane. Hexane dialysates were condensed and analyzed by gas

EWGs Tap Water Database Polychlorinated biphenyls (PCBs) results for Phoenixville Water Dept | Polychlorinated biphenyls (PCBs). Find out what is in your tap water

EWGs Tap Water Database Polychlorinated biphenyls (PCBs) results for Madison Water Works | Polychlorinated biphenyls (PCBs). Find out what is in your tap water

Dive into the research topics of Development of toxic equivalency factors for PCB congeners and the assessment of TCDD and PCB mixtures in rainbow trout. Together they form a unique fingerprint. ...

Background and aims: Despite the endocrine system activity exhibited by polychlorinated biphenyls (PCBs), recent studies have shown little association between PCB exposure and breast cancer mortality. To evaluate the relation between PCB exposure and breast cancer incidence, a more sensitive endpoint than mortality, we studied women exposed to PCBs while employed in capacitor manufacturing facilit

In vitro analysis of polychlorinated biphenyls (PCBs) and 2,3,4,7,8-pentachlorodibenzofuran (PCDF) cellular toxicity in PLC/PRF/5 cell proliferation--the effect of ursodeoxycholic acid, inchin-gorei-san and shou-saiko-to on cell toxicity.

Other data set: Additional PCB congeners are reported under data file name PCBPOL_F. Among these PCB congeners PCB 105, 114, 118, 156, 157, 167 and 189 has a toxic equivalence factor (TEF) and may be used with this data set for calculating a total TCDD equivalence.. Subsample Weights. PCDDs, PCDFs, and cPCBs were measured in a one-third subsample of participants 12 years and older. Special sample weights are required to analyze these data properly. Specific sample weights for this subsample are included in this data file and should be used when analyzing these data.. Samples were pooled in groups of 8 samples per pool within 40 demographic groups. The analysis of NHANES 2009-2010 pooled-sample data must be conducted with the basic demographic variables provided in this data file. This pooled-sample data file cannot be linked to other NHANES 2009-2010 data. Because each sample person does not have an equal probability of selection, sample weighting is needed to produce correct population ...

Persistent organic pollutants (POPs) are fat soluble chemical substances that persist in the environment and bioaccumulate in the food chain. Through long-range environmental transportation by air, water and migratory species they are transferred to new locations distant from the source of release and might cause adverse effects to human health and to the environment. POPs comprise pesticides, industrial chemicals and unwanted by-products. The European Commission has implemented food and feed legislations concerning maximum permitted levels (MPLs) of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), dioxin-like polychlorinated biphenyls (DLPCBs), polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs). Fish and consequently fishmeal and fish oil has been identified as one of the most important contributors to the level of dioxins and DL-PCBs in food and feed products. Fish caught in some of the North-European fishing areas contain high dioxin and PCB levels resulting ...

Polychlorinated Biphenyls (PCBs) are synthetic organic chemicals. Uses include plasticisers in paints, plastics & rubber PCBs are a persistent organic pollutant

The microbial synthesis of polyhydroxyalkanoates (PHA) from organic wastes is a valuable process to valorize available renewable resources, such as food wastes and biological sludge. Bioplastics find many applications in various sectors, from medical field to food industry. However, persistent organic pollutants could be transferred from wastes to the final product. The present paper demonstrates that the use of municipal wastes in PHA production is safe for the environment and human health and provides a polychlorinated biphenyl (PCB) profile in both commercial and waste-based PHA samples. PCB analysis in several PHA samples showed very low concentrations of the target analytes. Commercial PHA samples showed a similar PCB level with respect to PHA samples from municipal waste/sludge and higher than PHA samples from fruit waste. For all analyzed PCBs, detected concentrations were consistently lower than the ones reported in regulatory framework or guidelines.

Polychlorinated biphenyls (PCBs) are a group of synthetic organic chlorine compounds known as an organic pollutant in food sources, which play important ro

The developing central nervous system is particularly vulnerable to environmental contaminants such as non-dioxin-like polychlorinated biphenyls (NDL-PCBs). This study investigated the potential oxidative effects in mice pups exposed via lactation to the sum of the six indicator NDL-PCBs (Sigma 6 NDL-PCBs) at 0,1, 10 and 100 ng/kg per 14 days, constituting levels below the guidance values fixed by French food safety agencies for humans at 10 ng/kg body weight per day. For this purpose, the oxidative status was assessed by flow cytometry via dichloro-dihydro-fluorescein diacetate in the cerebellum of juvenile male offspring mice during brain growth spurt [postnatal day (PND) 14]. No significant differences were found in the levels of reactive oxygen species in the cerebellar neurons or glial cells (astrocytes, oligodendrocytes and microglia) of lactationally exposed male mice at PND 14 (p | 0.05). Concordantly, oxidative-stress related gene expression was measured by qPCR for catalase, copper zinc

Background: Polychlorinated biphenyls (PCBs) and their hydroxylated metabolites (HO-PCBs) interfere with thyroid hormone action both in vitro and in vivo. However, epidemiologic studies on the link between PCB exposure and thyroid function have yielded discordant results, while very few data are available for HO-PCBs. Objectives: Our study aimed at investigating the relationship between clinically available markers of thyroid metabolism and serum levels of both PCBs and HO-PCBs. Subjects and Methods: In a group of 180 subjects, thyroid-stimulating hormone (TSH) and free thyroxin (fT4), 29 PCBs (expressed both in lipid weight and in wet weight) and 18 HO-PCBs were measured in serum. Results: In regression models, adjusted for gender, age, current smoking behavior, BMI and total lipid levels, serum levels of 3HO-PCB118 and 3HO-PCB180, and PCB95lw, PCB99lw and PCB149lw were independent, significant predictors of fT4. A stepwise, multiple regression with gender, age, current smoking behavior, BMI and total

Polychlorinated biphenyl (PCB) exposure may affect serum concentrations of polyunsaturated fatty acids (PUFAs) by inhibiting desaturases Δ5 and Δ6 that drive their synthesis from precursor fatty acids. Such changes in the composition of fatty acids may affect cardiovascular disease risk, which is thought to increase at elevated PCB exposures. This population-based cross-sectional study examined 712 Faroese men and women aged 70-74 years. The serum phospholipid fraction of fasting blood samples was used to determine the PUFA profile, including linoleic acid, dihomo-γ-linolenic acid, arachidonic acid, eicosatrienoic acid, and other relevant fatty acids. Ratios between precursor and metabolite fatty acids were used as proxies for Δ5 and Δ6 desaturase activity. Tertiles of serum-PCB concentrations were used in multiple regression analyses to determine the association between the exposure and desaturase activity. In multiple regression models, PCB exposure was inversely related to the estimated ...

The most common technique used for the analysis of Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) at trace level is gas chromatography coupled to an electron capture detector (GC-ECD). Click to read more...

This industrial hygiene summary report summarizes available information about workers who manufactured polychlorinated biphenyl (PCB) filled capacitors at plant 3. Production started in October 1957 and ended in March 1977. Complete work history records for 3,603 workers were microfilmed in March 1977 and 40 personal and 16 area air samples were collected for the evaluation of PCB exposures (NIOSH

Chromosomal abnormalities contribute substantially to reproductive problems, but the role of environmental risk factors has received little attention.,We evaluated the association of polychlorinated biphenyl (PCB) and dichlorodiphenyldichloroethylene (p,p-DDE) exposures with sperm sex-chromosome disomy.,We conducted a cross-sectional study of 192 men from subfertile couples. We used multiprobe fluorescence in situ hybridization (FISH) for chromosomes X, Y, and 18 to determine XX, YY, XY, and total sex-chromosome disomy in sperm nuclei. Serum was analyzed for concentrations of 57 PCB congeners and p,p-DDE. Poisson regression models were used to calculate incidence rate ratios (IRRs) for disomy by exposure quartiles, controlling for demographic characteristics and semen parameters.,The median percent disomy was 0.3 for XX and YY, 0.9 for XY, and 1.6 for total sex-chromosome disomy. We observed a significant trend of increasing IRRs for increasing quartiles of p,p-DDE in XX, XY, and total ...

Dioxin-like chemicals and brominated flame retardants are ubiquitous in the environment, despite the introduction of international prohibitions and restrictions. These chemicals do not remain in the vicinity of their source, instead they can be transported over long distances, in fact even to pristine areas in the northern latitudes. However, there have been rather few time series experiments monitoring the trends in the levels of chlorinated and brominated forms of these chemicals in the environment. In this study, the concentrations of polychlorinated dibenzo-p-dioxins and -furans (PCDDs/Fs), polychlorinated biphenyls (PCBs) and polybrominated diethyl ethers (PBDEs) were measured in the liver and muscle of bank voles (Myodes glareolus) caught in a remote area in Finnish Lapland during 1986-2007. Five time points were selected: years 1986, 1992, 1998, 2003 and 2007. The levels of PCDDs/Fs and PCBs declined from 1986 until 2003 in both females and males, but tended to increase again in 2007. The peak

TY - JOUR. T1 - Identification of Sex-Specific Transcriptome Responses to Polychlorinated Biphenyls (PCBs). AU - Espin-Perez, Almudena. AU - Hebels, Dennie G. A. J.. AU - Kiviranta, Hannu. AU - Rantakokko, Panu. AU - Georgiadis, Panagiotis. AU - Botsivali, Maria. AU - Bergdahl, Ingvar A.. AU - Palli, Domenico. AU - Spath, Florentin. AU - Johansson, Anders. AU - Chadeau-Hyam, Marc. AU - Kyrtopoulos, Soterios A.. AU - Kleinjans, Jos C. S.. AU - de Kok, Theo M. C. M.. PY - 2019/1/24. Y1 - 2019/1/24. KW - PERSISTENT ORGANIC POLLUTANTS. KW - GENE-EXPRESSION ANALYSIS. KW - CARDIOVASCULAR-DISEASE. KW - CARCINOMA-CELLS. KW - IMMUNE-SYSTEM. KW - CANCER. KW - LYMPHOMA. KW - EXPOSURE. KW - SUPPRESSION. KW - HEALTH. U2 - 10.1038/s41598-018-37449-y. DO - 10.1038/s41598-018-37449-y. M3 - Article. C2 - 30679748. VL - 9. SP - 1. EP - 12. JO - Scientific Reports. JF - Scientific Reports. SN - 2045-2322. M1 - 746. ER - ...

Despite production having stopped in the 1970s, polychlorinated biphenyls (PCBs) represent persistent organic pollutants that continue to pose a serious human health risk. Exposure to PCBs has been...

Several studies have suggested that exposure to persistent pollutant, polychlorinated biphenyls (PCBs), may increase the risk of developing endometriosis

Background: Multiple studies have suggested a relationship between adult exposures to environmental organochlorines and fecundability. There is a paucity of data, however, regarding fetal exposure to organochlorines via the mothers blood and fecundability of adult female offspring. Methods: Data from a two-generation cohort of maternal fisheaters was investigated to assess female offspring fecundability. Serum concentrations of polychlorinated biphenyls (PCBs) and 1,1-bis-(4-chlorophenyl)-2,2-dichloroethene (DDE) in Michigan female anglers were serially measured between 1973 and 1991 and used to estimate in utero exposure in their female offspring using two different methods. The angler cohort included 391 women of whom 259 provided offspring information. Of 213 daughters aged 20-50, 151 participated (71 %) and provided information for time intervals of unprotected intercourse (TUI). The daughters reported 308 TUIs (repeated observations), of which 288 ended in pregnancy. We estimated the ...

PCBs are a group of synthetic organic chemicals that can cause a number of different harmful effects. There are no known natural sources of PCBs in the environment. PCBs are either oily liquids or solids and are colorless to light yellow. Some PCBs are volatile and may exist as a vapor in air. They have no known smell or taste. PCBs enter the environment as mixtures containing a variety of individual chlorinated biphenyl components, known as congeners, as well as impurities

A mortality study was conducted in workers with at least 90 days exposure to polychlorinated biphenyls PCBs between 1946 and 1977. Vital status was established for 98.7% of the 7075 workers studied. In hourly male workers, the mortality from all cancers was significantly below expected standardized mortality ratio SMR=81 ; 95% confidence...

A method is described for the analysis of polychlorinated biphenyl (PCB) compounds in tissue samples. Cleanup by hexane-aceto-nitrile partitioning and Florisil column chromatography are performed on samples before oxidative treatment to convert DDE to DCBP. PCB components are then determined semi-quantitatively by TLC. No prior separation of PCB from chlorinated pesticides is required. The lower limit of sensitivity is 0.2 ?g....

Polychlorinated biphenyls (PCBs) and hydroxylated PCBs (OH-PCBs) were investigated in human adipose tissue samples collected from 20 women undergoing surgery. Mean sum of PCB and sum of OH-PCB levels were 737ng/g of lipid and 8pg/g of lipid, respectively. Among PCBs, congeners 180, 153, 138 and 170 were the most frequent and abundant, and together constituted 72% of the total amount of PCBs in adipose tissue. The PCB congener pattern and the frequencies and concentrations of non-dioxin-like and non-hydroxylated congeners observed in adipose tissue were similar in distribution and order of magnitude to the profile previously published in Spain but lower than that found in other European countries. Among OH-PCB congeners studied, 4-OH-PCB 107/118 was found at the highest concentrations followed by 3-OH-PCB 180 and 3-OH-PCB 138. To date, no information on levels of PCB metabolites in the Spanish population is available for comparison. These three predominant OH-PCBs contributed 97% of all OH-PCBs. ...

Polychlorinated biphenyls (PCBs) are ubiquitous environmental pollutants. In the past, many commercial technologies have been used to clean up highly contaminated areas, but these methods are often very costly. An anaerobic/aerobic bioremediation process would be a simpler and cheaper alternative, but many aspects of this process are not understood, making the process of bioremediation difficult to implement. Aerobic PCB oxidation has been widely studied and microorganisms capable of this action have been isolated. Anaerobic dechlorination has also been well documented, but the responsible microorganisms have not been identified. Understanding the microbial community structure is required for optimizing an acceptable bioremediation process. This study attempted to address this lack of knowledge, in part, with two objectives. The first objective involved establishing cultures capable of dechlorinating 2,3,4,5-tetrachlorobiphenyl (CB) and its dechlorination products, 2,3,5-CB, 2,4,5-CB and 3,5-CB. ...

Linh hoạt thay thế cho Chất thải xử lý ô nhiễm Polychlorinated biphenyls (PCBs) và các hợp chất thơm khác được khử trùng bằng clo được phân phối trong đất, bùn cặn, cửa sông, vv, tại hơn 400 trang web trong Hoa Kỳ một mình. Clo béo hydrocarbon (CAHs), rộng rãi được sử dụng để tẩy dầu mỡ và làm sạch động cơ, phụ tùng ô tô, và các thành phần điện tử, chất gây ô nhiễm nghiêm trọng tại 358 lớn các trang web trong chất thải nguy hại Hoa Kỳ. ...

Article Abundances, Depositional Fluxes, and Homologue Patterns of Polychlorinated Biphenyls in Dated Sediment Cores from the Pearl River Delta, China. Despite the recent efforts to investigate the distribution and fate of persistent organic pollutan...

TY - JOUR. T1 - Serum persistent organic pollutants (POPs) and prostate cancer risk. T2 - A case-cohort study. AU - Lim, Jung eun. AU - Nam, Chungmo. AU - Yang, Jiyeon. AU - Rha, KoonHo. AU - Lim, Kyung Min. AU - Jee, Sun Ha. PY - 2017/7/1. Y1 - 2017/7/1. N2 - It is still unclear whether persistent organic pollutants (POPs) exposure increases the prostate cancer incidence risk. This prospective cohort study evaluated the associations between serum POPs concentrations and prostate cancer risk. Within a case-cohort study, we identified 110 people diagnosed with prostate cancer and randomly selected 256 sub-cohort participants without prostate cancer. Serum concentrations of 32 polychlorinated biphenyl (PCB) congeners and 19 organochlorine pesticides (OCPs) were measured. The hazard ratios (HRs) and 95% confidence interval (95% CI) for determining the associations between POPs and risk of prostate cancer were estimated using the weighted Cox regression model. Compared to the lowest tertile, ...

Polychlorinated dibenzofurans (PCDFs) are a family of organic compounds with one or several of the hydrogens in the dibenzofuran structure replaced by chlorines. For example, 2,3,7,8-tetrachlorodibenzofuran (TCDF) has chlorine atoms substituted for each of the hydrogens on the number 2, 3, 7, and 8 carbons (see structure in the upper left corner of the second image). Polychlorinated dibenzofurans are much more toxic than the parent compounds, with properties and chemical structures similar to polychlorinated dibenzodioxins. These groups together are often inaccurately called dioxins. They are known teratogens, mutagens, and suspected human carcinogens. PCDFs tend to co-occur with polychlorinated dibenzodioxins (PCDDs). PCDFs can be formed by pyrolysis or incineration at temperatures below 1200 °C of chlorine containing products, such as PVC, PCBs, and other organochlorides, or of non-chlorine containing products in the presence of chlorine donors. Dibenzofurans are known persistent organic ...

Dioxins and dioxin-like compounds (DLCs) are compounds that are highly toxic environmental persistent organic pollutants (POPs). They are mostly by-products of various industrial processes - or, in case of dioxin-like PCBs and PBBs, part of intentionally produced mixtures. They include: Polychlorinated dibenzo-p-dioxins (PCDDs), or simply dioxins. PCDDs are derivatives of dibenzo-p-dioxin. There are 75 PCDD congeners, differing in the number and location of chlorine atoms, and seven of them are especially toxic, the most dangerous being 2,3,7,8-Tetrachlorodibenzodioxin (TCDD) Polychlorinated dibenzofurans (PCDFs), or furans. PCDFs are derivatives of dibenzofuran. There are 135 isomers, ten have dioxin-like properties. Polychlorinated/polybrominated biphenyls (PCBs/PBBs), derived from biphenyl, of which twelve are dioxin-like. Under certain conditions PCBs may form dibenzofurans/dioxins through partial oxidation. Finally, dioxin may refer to 1,4-Dioxin proper, the basic chemical unit of the ...

TY - JOUR. T1 - Study of polychlorinated biphenyls as potential modifiers of developmental neurotoxicity of methylmercury. AU - Coccini, Teresa. AU - Castoldi, Anna F.. AU - Roda, Elisa. AU - Sarigiannis, Dimosthenis A.. AU - Manzo, Luigi. PY - 2008. Y1 - 2008. N2 - The developing brain is the most susceptible target for methylmercury (MeHg) toxicity. Typical features of developmental MeHg neurotoxicity include the delayed onset of symptoms and the persistency of dysfunction. One of the factors which may modulate MeHg neurotoxicity is co-exposure to other neurotoxic pollutant, e.g. polychlorinated biphenyls (PCBs) from the same dietary sources. Because PCBs themselves can induce subtle neurodevelopmental deficiencies, recent epidemiological and research studies have focused on the potential hazard resulting from mixtures of PCBs and MeHg. This work summarizes our experimental findings on several endpoints of the cholinergic and aminergic systems in the developing rat brain, following two ...

TY - JOUR. T1 - Structure-dependent reduction in DNA I-compound adducts by polychlorinated dibenzofurans in female Sprague-Dawley rat liver. AU - Randerath, K.. AU - Randerath, E.. AU - Reddy, R.. AU - Narasimhan, T. R.. AU - Wang, X.. AU - Safe, S.. PY - 1992. Y1 - 1992. N2 - The effects of polychlorinated dibenzofurans (PCDFs) on hepatic I-compound DNA adducts in female Sprague-Dawley rats were determined at 2 dose levels. In the first experiments, rats (4 per group) were treated with each of 3 polychlorinated dibenzofuran (PCDF) congeners at 20 μg/kg/week or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) at 10 μg/kg/week for 4 weeks. Effects on total I-compound levels when compared with age-matched control animals (corn oil) were as follows: control (116) , 1,2,4,7,8-pentachlorodibenzofuran (PeCDF) (112) , 1,2,3,7,8-PeCDF (93) , 2,3,4,7,8-PeCDF (91) , TCDD (72) where the numbers in parentheses were the number of I-compounds in 109 DNA nucleotides. In the second experiment, rats (5 per group) ...

Changes in atropisomer composition of chiral polychlorinated biphenyls (PCBs) and their mono- and dihydroxylated metabolites (OH- and diOH-PCBs) via rat cytochrome P450 2B1 (CYP2B1) mediated biotransformation were investigated in vitro. Rat CYP2B1 could stereoselectively biotransform chiral PCBs to generate meta-OH-PCBs as the major metabolites after 60 min incubations. Nonracemic enantiomer fractions (EFs: concentration ratios of the (+)-atropisomer or the first-eluting atropisomer over the total concentrations of two atropisomers) of 5-OH-PCBs, were 0.17, 0.20, 0.85, 0.77, and 0.41 for incubations with PCBs 91, 95, 132, 136, and 149, respectively. CYP-mediated stereoselective formation of diOH-PCBs from OH-PCBs was observed for the first time. After 60 min stereoselective biotransformation, the EFs of both 4-OH-PCB 95 and 5-OH-PCB 95 changed from racemic (i.e., 0.50) to 0.62 and 0.46, respectively. These transformations generated statistically nonracemic 4,5-diOH-PCB 95, with EFs of 0.53 and 0.58 for

Spens, K. (2003) Community strategy on dioxins, furans and polychlorinated biphenyls and the EU Implementation of the Stockholm Convention and the UN ECE Protocol on POPs. Persistent Toxic Substances Contamination of the European Region as a reflection of results of the GEF/UNEP Regional Based Assessment of Persistent Toxic Substances (RBA PTS) in Europe, the implementation of the Stockholm Convention and Community Strategy for Dioxins, Furans and PCBs ...

TY - JOUR. T1 - Inhibition of intercellular communication and induction of ethoxyresorufin-O-deethylase activity by polychlorobiphenyls, -dibenzo-p-dioxins and -dibenzofurans in mouse hepa1c1c7 cells.. AU - de Haan, L.H.J.. AU - Halfwerk, S.. AU - Hovens, S.E.L.. AU - de Roos, B.. AU - Koeman, J.H.. AU - Brouwer, A.. PY - 1996. Y1 - 1996. U2 - 10.1016/1382-6689(95)00006-2. DO - 10.1016/1382-6689(95)00006-2. M3 - Article. VL - 1. SP - 27. EP - 37. JO - Environmental Toxicology and Pharmacology. JF - Environmental Toxicology and Pharmacology. SN - 1382-6689. ER - ...

Since 1987, the World Health Organization (WHO) carried out global surveys on polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in human milk. This study presents a review of the three most recent surveys from 2000 to 2010, including DDT. The objective was to identify global quantitative differences and provide baseline information for 52 countries or provide time-trends for countries with previous data. Individual human milk samples were collected following a WHO-designed procedure and combined to form a national pooled sample. Here, we report global levels for PCDDs, PCDFs, PCBs and the sum of o,p′-DDT, p,p′-DDT, o,p′-DDE, p,p′-DDE, o,p′-DDD and p,p′-DDD (ΣDDTs). A concise risk-benefit evaluation related to human milk contamination with these persistent organic pollutants (POPs) was also done. Large global and regional differences were observed. Levels of PCDDs and PCDFs were highest in India and some European and ...

Chiral PCB congeners are main the different parts of PCB mixtures and undergo enantioselective biotransformation to hydroxylated (OH-)PCBs by cytochrome P450 enzymes. 91, 95, 132 and 149. The OH-PCBs had been extracted through the microsomal incubations, derivatized with diazomethane and examined as the particular methoxylated (MeO-)PCB derivatives using chosen columns. The 5-hydroxylated metabolites of PCBs 91, 95, 132 and 149 had been the main metabolites, which can be in keeping with PCBs biotransformation by cytochrome P450 2B enzymes. All 5-hydroxylated metabolites shown a definite, congener-specific enantiomeric enrichment. General, this scholarly research demonstrates for the very first time that chiral PCBs, such as for example PCB 91, 95, 132 and 149, are metabolized to OH-PCBs by cytochrome P450 enzymes enantioselectively. and lactational exposures to multiple-substituted PCB congeners correlate with reduced intelligence quotients, impaired learning and memory, attentional deficits, ...

Dioxins refers to a group of persistent chlorinated chemical compounds that have similar chemical structures and properties, and have similar biological characteristics, including toxicity. Food Standards Australia New Zealand (FSANZ) has conducted an analytical survey of dioxins in a range of food sampled in Australia with the purpose of assessing the level of risk to human health associated with the dietary exposure of the Australian population to dioxins. The overall conclusion of this report is that, on the basis of the available data, taking into account all the inherent uncertainties and limitations, the public health and safety risk for all Australians from exposure to dioxins from foods is very low.. Dioxins includes the polychlorinated dibenzodioxins (PCDDs or dioxins), the closely related polychlorinated dibenzofurans (PCDFs or furans) and polychlorinated biphenyls (dioxin-like PCBs, or PCBs). These compounds can accumulate in the body fat of animals and humans and have a tendency ...

In this work, we examined the profile of metabolites produced from the doubly para-substituted biphenyl analogs 4,4-dihydroxybiphenyl, 4-hydroxy-4-chlorobiphenyl, 3-hydroxy-4,4-dichlorobiphenyl, and 3,3-dihydroxy-4,4-chlorobiphenyl by biphenyl-induced Pandoraea pnomenusa B356 and by its biphenyl dioxygenase (BPDO). 4-Hydroxy-4-chlorobiphenyl was hydroxylated principally through a 2,3-dioxygenation of the hydroxylated ring to generate 2,3-dihydro-2,3,4-trihydroxy-4-chlorobiphenyl and 3,4-dihydroxy-4-chlorobiphenyl after the removal of water. The former was further oxidized by the biphenyl dioxygenase to produce ultimately 3,4,5-trihydroxy-4-chlorobiphenyl, a dead-end metabolite. 3-Hydroxy-4,4-dichlorobiphenyl was oxygenated on both rings. Hydroxylation of the nonhydroxylated ring generated 2,3,3-trihydroxy-4-chlorobiphenyl with concomitant dechlorination, and 2,3,3-trihydroxy-4-chlorobiphenyl was ultimately metabolized to 2-hydroxy-4-chlorobenzoate, but hydroxylation of the ...

TY - JOUR. T1 - Identification of the bphA and bphB Genes of Pseudomonas sp. Strain KKS102 Involved in degradation of biphenyl and polychlorinated biphenyls. AU - Fukuda, Masao. AU - Yasukochi, Yuji. AU - Kikuchi, Yutaka. AU - Nagata, Yuji. AU - Kimbara, Kazuhide. AU - Horiuchi, Hiroyuki. AU - Takagi, Masamichi. AU - Yano, Keiji. PY - 1994/7/29. Y1 - 1994/7/29. N2 - The nucleotide sequence of the upstream region of the bphC gene from Pseudomonas sp. strain KKS102 was determined. Four genes were found in this region. Deduced amino acid sequences of the first, second, third and fourth genes showed significant homology with a large subunit of iron-sulfur protein, a small subunit of iron-sulfur protein, ferredoxin and dihydrodiol dehydrogenase, respectively, from other bacteria which degrade biphenyl/polychlorinated biphenyls, toluene and benzene. E. coli, in which the four genes, bphC and the gene for ferredoxin reductase from benzene degrading bacterium were expressed, was able to produce ...

POLYCHLORINATED NAPHTHALENE (PCN) AND DIBENZOFURAN (PCDF) CONGENER PATTERNS FROM PHENOL PRECURSORS IN THERMAL PROCESS: [II] EXPERIMENTAL RESULTS FROM DICHLOROPHENOLS (DCPs) - Municipal waste incinerator;Thermal process;Combustion;Polychlorinated Naphthalenes;Polychlorinated Dibenzofurans;Chlorophenol;

Dioxins and polychlorinated biphenyls (PCBs) are toxic chemicals that persist in the environment and accumulate in the food chain. Their presence in the environment in Europe has declined since the 1970s, following concerted efforts by public authorities and industry.. In the context of EFSAs work, dioxins refers to two groups of compounds: Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Dioxins have no technological or other use, but are generated in a number of thermal and industrial processes as unwanted and often unavoidable by-products. In contrast to dioxins, PCBs had widespread use in numerous industrial applications, and were produced in large quantities for several decades with an estimated total world production of 1.2-1.5 million tonnes, until they were banned in most countries by the 1980s.. Dioxins and PCBs are found at low levels in many foods. Longer-term exposure to these substances has been shown to cause a range of adverse effects on the nervous, immune ...

Dioxins and polychlorinated biphenyls (PCBs) are toxic chemicals that persist in the environment and accumulate in the food chain. Their presence in the environment in Europe has declined since the 1970s, following concerted efforts by public authorities and industry.. In the context of EFSAs work, dioxins refers to two groups of compounds: Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Dioxins have no technological or other use, but are generated in a number of thermal and industrial processes as unwanted and often unavoidable by-products. In contrast to dioxins, PCBs had widespread use in numerous industrial applications, and were produced in large quantities for several decades with an estimated total world production of 1.2-1.5 million tonnes, until they were banned in most countries by the 1980s.. Dioxins and PCBs are found at low levels in many foods. Longer-term exposure to these substances has been shown to cause a range of adverse effects on the nervous, immune ...

Human transition milk was sampled from 88 mothers at the Faroe Islands, where the seafood diet includes pilot whale meat and blubber. Milk mercury concentrations (median, 2.45 micrograms/liter) were significantly associated with mercury concentrations in cord blood and with the frequency of pilot wh …

Latest findings suggest that the chemicals, which are no longer produced in the United States but persist in the environment, may have lasting health effects even at low levels. POPs, PBTs and vPvBs There are three groups of persistent substances mentioned in regulations: - POP, Persistent Organic Pollutants - PBT, Persistent, Bio-accumulative and Toxic substances - vPvB, very Persistent and very Bio-accumulative substances Persistent means that these substances will not (bio)degrade. The new regulation repeals the POP Regulation (EC) No 850/2004 and comes into force on 15 July 2019. L 169, 25.6.2019, p. 45). 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. sponsor this page to leave your contact info on this page.. Persistent Organic Pollutant. Stockholm, Basel, Rotterdam and Geneva) provisions have been established. ...

Persistent organic pollutants (POPs) are a large group of chemicals widely used and produced in various industrial applications. Many cell culture/animal studies have shown that POPs can induce oxidative stress. Since such data is lacking in humans, we conducted a large population-based study to analyze associations between POPs and oxidative stress markers. We measured following POPs; 16 polychlorinated biphenyls (PCBs), 5 organochlorine (OC) pesticides, octachlorinated dibenzo-p-dioxin, and polybrominated diphenyl ether 47, and oxidative stress markers; homocysteine, reduced [GSH] and oxidized glutathione [GSSG], glutathione ratio [GSSG/GSH], total glutathione, oxidized low-density lipoprotein [ox-LDL], ox-LDL antibodies, conjugated dienes, baseline conjugated dienes of LDL, and total anti-oxidative capacity in plasma samples collected from 992 70-year old individuals (50% women) from the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) cohort. Linear ...

Emissions of a number of compounds categorised as persistent organic pollutants (POPs) - e.g. hexachlorobenzene (HCB, by 92%), hexachlorocyclohexane (HCH, by 85%), polychlorinated biphenyls (PCBs, by 75%), dioxins & furans (by 83%), and poly-aromatic hydrocarbons (PAHs, by 61%) - decreased between 1990 and 2012 in the EEA-33 countries. While the majority of countries report that POPs emissions fell during this period, a number report that increased emissions occurred. In 2012, the most significant sources of emissions for these POPs included Commercial, institutional and households (10% of HCB, 32% of dioxins and furans, 16% of PCBs) and Industrial processes (70% of HCB, 32% of HCH, 27% of PCBs) sectors.

Served as the lead human health risk assessment consultant in the preparation of a focused feasibility study and remedial action plan, and notification plan specifically for polychlorinated biphenyls (PCBs) for a former cast plate facility. Managed the development of site-specific risk-based screening levels for various chemicals in soil or soil vapor, including PCBs as Aroclor mixtures and dioxin-like congeners, for multiple receptors and exposure pathways. As part of the development of risk-based remediation goals, conducted a series of regression analyses to evaluate the relationship between the results of Aroclor mixture and dioxin-like PCB congener analyses and estimate a formula that could be used to: 1) estimate dioxin toxic equivalent concentrations for samples only analyzed for Aroclors, 2) support (or refine) proposed risk-based remediation goals based on Aroclor concentrations, and 3) support remediation confirmation sampling at a significantly reduced cost.. ...

1 PublKat: A11 (Artikkel i internasjonalt vitenskapelig tidsskrift med referee) Instit: Universitetet i Bergen, Det matematisk-naturvitenskapelige fakultet, Molekyl rbiologisk institutt Forf: Aas, Endre Medforf: Beyer, Jonny Medforf: Goks yr, Anders UiB, Molekyl rbiologisk institutt Tittel: PAH in fish bile detected by fixed wavelength fluorescence Tidskr: Marine Environmental Research Red: Widdows, J Red: Luoma, S.N. ISSN: 0141-1136 r: 1998 Volum: 46 Hefte: 1-5 Side(r): 225-228 Utgiver: Elsevier Spr k: eng PublID: r99000791 2 PublKat: C15 (Hovedfagsoppgave) Instit: Universitetet i Bergen, Det matematisk-naturvitenskapelige fakultet, Molekyl rbiologisk institutt Forf: Addo, Matthew Glover Tittel: The effect of polychlorinated biphenyls on cod (Gadus morhua) zona radiata, prolactin and cytochrome P4501A gene expression Serie: cand.scient.-oppgave r: 1998 Side(r): IX, 57 bl. Tilgang: UBBRB Emneord: molekyl rbiologi Spr k: eng PublID: r98025975 StatKat: f 3 PublKat: C15 (Hovedfagsoppgave) Instit: ...

EEA-33 emissions of a number of compounds categorised as persistent organic pollutants (POPs) have decreased between 1990 and 2011, including hexachlorobenzene (HCB) by 96%, hexachlorocyclohexane (HCH) by 95%, polychlorinated biphenyls (PCBs) by 73%, dioxins & furans by 84%, and poly-aromatic hydrocarbons (PAHs) by 58%. While the majority of individual countries report that POP emissions have fallen during this period, a number report that increases in emissions of one or more pollutants have occurred. In 2011, the most significant sources of emissions for these POPs included the sectors Commercial, institutional and households (61% for PAHs, 19% of HCB, 39% of dioxins and furans, 15% of PCB emissions) and Industrial processes (43% of HCB, 75% of HCH, 38% of PCB emissions). Important emission sources of PAH include residential combustion processes (open fires, coal and wood burning for heating purposes etc.), industrial metal production processes, and the road transport sector. Emissions

Experimental studies have shown that dioxin-like chemicals may interfere with aspects of the endocrine system including growth. However, human background population studies are, however, scarce. We aimed to investigate whether early exposure of healthy infants to dioxin-like chemicals was associated …

High quality reference standard solutions for use in environmental/analytical testing and toxicological research. Wellington Laboratories offers an extensive inventory of individual certified reference standards and solution mixtures of native and mass-labelled halogenated organic compounds including polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, polychlorinated biphenyls, halogenated flame retardants and perfluorinated compounds. Wellington Laboratories also offer a variety of calibration sets and support solutions designed to be used for common regulatory methods or modified in-house methods

In 1865 the first PCB-like chemical was discovered, and was found to be a byproduct of coal tar. Years later in 1881, German chemists synthesized the first PCB in a laboratory. Between then and 1914, large amounts of PCBs were released into the environment, to the extent that there are still measurable amounts of PCBs in feathers of birds currently held in museums.[57]. In 1935, Monsanto Chemical Company (now Solutia Inc) took over commercial production of PCBs from Swann Chemical Company which had begun in 1929. PCBs, originally termed chlorinated diphenyls, were commercially produced as mixtures of isomers at different degrees of chlorination. The electric industry used PCBs as a non-flammable replacement for mineral oil to cool and insulate industrial transformers and capacitors. PCBs were also commonly used as heat stabilizer in cables and electronic components to enhance the heat and fire resistance of PVC.[58]. In the 1930s, the toxicity associated with PCBs and other chlorinated ...

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This standard is developed for the purposes of enforcing the Law of the Peoples Republic of China on Environmental Protection, protecting the environment, safeguarding the public health, and setting standards for PCBs in soil and sediment. This standard specifies the gas chromatography-mass spectrometry method for the determination of PCBs in soil and sediment. It is the original version.. ...

Air and seawater samples were collected on board the RV Polarstern during a cruise from Bremerhaven, Germany to Cape Town, South Africa from October-November 2005. Broad latitudinal trends were observed with the lowest Σ27PCB air concentration (10 pg m−3) in the South Atlantic and the highest (1000 pg m−3) off the west coast of Africa. ΣICESPCBs ranged from 3.7 to 220 pg m−3 in air samples and from 0.071 to 1.7 pg L−1 in the dissolved phase seawater samples. Comparison with other data from cruises in the Atlantic Ocean since 1990 indicate little change in air concentrations over the remote open ocean. The relationship of gas-phase partial pressure with temperature was examined using the Clausius-Clapeyron equation; significant temperature dependencies were found for all PCBs over the South Atlantic, indicative of close air-water coupling. There was no temperature dependence for atmospheric PCBs over the North Atlantic, where concentrations were controlled by advection of contaminated ...

BACKGROUND: We performed a cross-sectional study of associations between personal characteristics and lipid-adjusted serum concentrations of certain PCB congeners and chlorinated pesticides/metabolites among 323 pregnant primiparous women from Uppsala County (age 18-41 years) sampled 1996-1999. METHODS: Extensive personal interviews and questionnaires about personal characteristics were performed both during and after pregnancy. Concentrations of organochlorine compounds in serum lipids in late pregnancy were analysed by gas chromatography. Associations between personal characteristics and serum levels of organochlorine compounds were analysed by multiple linear regression. RESULTS: Participation rate was 82% (325 of 395 women). Serum concentrations of PCB congeners IUPAC no. 28, 52, 101, 105 and 167, and o, p-DDT and -DDE, p, p-DDT and -DDD, oxychlordane, and gamma- and alpha-HCH were in many cases below the limit of quantification (LOQ). No statistical analysis of associations with personal ...

The biphenyl molecule is made up of two connected rings of six carbon atoms each, and a PCB is any molecule having multiple chlorines attached to the biphenyl nucleus. Two distinct classes of bacteria have now been identified that biodegrade PCBs by different mechanisms, including aerobic bacteria which live in oxygenated environments and anaerobic bacteria which live in oxygen free environments such as aquatic sediments. The aerobes attack PCBs oxidatively , breaking open the carbon ring and destroying the compounds. Anaerobes, on the other hand, leave the biphenyl rings intact while removing the chlorines. Polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) were introduced into the biosphere on a large scale as by-products from the manufacture of chlorinated phenols and the incineration of wastes. Due to their high toxicity they have been the subject of great public and scientific scrutiny. The evidence in the literature suggests that PCDD/F compounds are subject ...

The United States Environmental Protection Agency (US EPA) guidelines allow removal of polychlorinated biphenyls (PCBs) from soils via solvent extraction. This option holds promise for removal of other recalcitrant organic contaminants as well. A study was undertaken to evaluate the effectiveness of solvent extraction with two tandem degradation techniques. The degradation techniques were chemical dehalogenation with immobilized reagents and γ-ray irradiation. The integrated approach was evaluated with contaminated soils from wood treatment and electric power substation sites. Evaluations were carried out on a bench scale in the laboratory and on a semi-pilot scale at a contaminated site. Binary solvent mixture of alkanes and alcohols yielded the highest extraction efficiencies. Extraction efficiencies in excess of 90% were obtained for PCBs, polychlorinated dibenzo-p-dioxins (PCDDs) and polynuclear aromatic hydrocarbons (PAHs). Extracted PCBs were rapidly degraded through chemical dehalogenation or

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Pacific Standard reports: On April 19, 1979, the United States Environmental Protection Agency announced a five-year plan to phase out nearly all uses of polychlorinated biphenyls, or PCBs. The synthetic chemicals had been used in the manufacture of electronic equipment, motor oil, adhesive tapes, paint, and many other products.. Although PCBs are no longer being produced in this country, we will now bring under control the vast majority of PCBs still in use, EPA administrator Douglas M. Costle boasted at the time. This will help prevent further contamination of our air, water, and food supplies from a toxic and very persistent manmade chemical.. It turns out Costle celebrated too early - way, way too early. More than 36 years after being banned, PCBs continue to pollute ecosystems, according to a study released in the journal PLoS One. They pose a particular challenge to the survival of marine mammals like porpoises, whales, and dolphins. [Continue reading…] ...

Background Polychlorinated biphenyls (PCB) are persistent organic pollutants (POP) that are consumed because of their bioaccumulation through the food chain. Recent studies have suggested the implication of POPs in the development of metabolic diseases such as type 2 diabetes and obesity. However, this relationship is not entirely consistent, and has not been investigated in longitudinal studies. The purpose of this study was to prospectively examine the association between dietary intake of PCBs and the incidence of obesity in the Seguimiento Universidad de Navarra (SUN) Project.. ...

Isotopic dilution gas chromatography combined with high resolution mass spectrometry (GC/HRMS) has overwhelming advantages with respect to the accuracy of congener-specific ultratrace analysis of complex persistent organic pollutants (POPs) in environmental matrices. However, an isotopic dilution GC/HRMS method for analysis of chlorinated and brominated polycyclic aromatic hydrocarbons (Cl-PAHs and Br-PAHs) using 13C-labelled congeners as internal standards has not been established. In this study, a method for identification and quantification of 38 congeners of Cl-PAHs and Br-PAHs in atmosphere and stack gas samples from waste incinerators was developed using the isotopic dilution GC/HRMS technique. The instrumental detection limits of the GC/HRMS method ranged from 0.2pg to 1.8pg for Cl-PAH congeners, and 0.7pg to 2.7pg for Br-PAH congeners, which were about three orders of magnitude lower than those of the GC/quadrupole MS method. This new method developed was also the first to enable ...

1) Bastiansen, O.; Samdal, S., Structure and barrier of internal rotation of biphenyl derivatives in the gaseous state: Part 4. Barrier of internal rotation in biphenyl, perdeuterated biphenyl and seven non-ortho-substituted halogen derivatives, J. Mol. Struct., 1985, 128, 115-125, DOI: 10.1016/0022-2860(85)85044-4.. (2) Sancho-Garcia, J. C.; Cornil, J., Anchoring the Torsional Potential of Biphenyl at the ab Initio Level: The Role of Basis Set versus Correlation Effects, J. Chem. Theory Comput., 2005, 1, 581-589, DOI: 10.1021/ct0500242.. (3) Johansson, M. P.; Olsen, J., Torsional Barriers and Equilibrium Angle of Biphenyl: Reconciling Theory with Experiment, J. Chem. Theory Comput., 2008, 4, 1460-1471, DOI: 10.1021/ct800182e.. ...

Between 1929 and 1989 an estimated 1.7 million metric tons of PCBs were produced commercially worldwide.2 These commercial PCBs were sold in the United States under dozens of different trade names, of which the most commonly known was Aroclor. These products were mixtures that contained different PCB congeners, each with between 1 and 10 chlorine atoms.3 (Unintentionally produced PCBs also typically occur as mixtures of congeners.) Each of the total 209 PCB congeners has a distinct structure that influences how it behaves environmentally and how it interacts with living cells and organisms.. Although large amounts of commercially produced PCBs remain in the environment, monitoring conducted at a number of sites around North America in the past five years or so has detected notable air concentrations of PCB congeners that are not part of the historical, now-banned commercial PCB products. These congeners have also been detected in U.S. water bodies including the Delaware River, the New York-New ...