Background levels of polychlorinated biphenyls in British soils

The concentrations of PCBs in soil samples collected at rural and urban locations in Britain are reported. PCBs were detected in all samples analysed, within the range 2.3 to 444 μg kg⁻¹ (ppb), with a mean concentration of 22.8 μg kg⁻¹ and a median value of 7.2 μg kg⁻¹. A distinct sub-group of samples has a range of 2.3 to 19.2 μg kg⁻¹, with a mean of 7.5 μg kg⁻¹ and a median value of 6.8 μg kg⁻¹. These values are consistent with published data from other industrialised countries. Measurement was carried out using a two stage clean-up of soil extracts, with concentrated sulphuric acid and florisil, followed by gas chromatography and electron capture detection.     

Detailed study on the levels of polychlorinated dibenzo-p-dioxins,polychlorinated dibenzofurans and polychlorinated biphenyls in Yusho rice oil

One bottle of Yusho rice oil was obtained from a Yusho family in 1998. The levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in the causal oil were investigated with two different approaches and the individual concentrations of all the 17 2,3,7,8-substituted PCDD/F and 14 coplanar PCB (Co-PCB) congeners were elucidated for the first time. The concentrations of PCDDs and PCDFs were found to be 0.60 and 8.8 ppm, respectively. For PCBs, more than 130 PCB peaks were observed and a total concentration of 850 ppm including 170 ppm of Co-PCBs was obtained. The toxic equivalents (TEQs) of PCDDs, PCDFs, and Co-PCBs were calculated to be 17, 470, and 120 ppb, respectively. The relative contribution of these classes to the total TEQ in Yusho oil is 3%, 77%, and 20%, respectively, indicating that PCDFs play a major role in the toxicity of Yusho oil. Furthermore, it was confirmed that 2,3,4,7,8-penta-CDF contributes 58% to the total TEQ, supporting the view that this compound is the principal causal agent in Yusho poisoning. It is noteworthy that the most toxic 2,3,7,8-tetra-CDD was newly discovered, although it contributes only 0.1% to the total TEQ. Based on our data, the smallest TEQ intake during the latent period was estimated to be 0.067 mg for Yusho patients. This value is about 60% of that previously reported, suggesting a lower minimum threshold level for the development of the toxic symptoms of Yusho.     

Transformer oils as a potential source of environmental exposure to polychlorinated biphenyls (PCBs): an assessment in three central provinces of Iran

Environmental Science and Pollution Research - Polychlorinated biphenyl (PCB) contamination of oils from all transformers of the national electrical grid in Tehran, Qom, and Alborz, three central...     

Levels of polychlorinated biphenyls and organochlorine pesticides in some edible marine organisms from the Central Adriatic Sea

Concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCs) were found in tissue of marine organisms such as Mediterranean mussel, Norway lobster, red mullet, common cuttle-fish, European flying squid, European anchovy, European pilchard and Atlantic mackerel, coming from two sites along the Abruzzo coast of the Adriatic Sea. Species were selected due to their habitat, trophic level, feeding behaviour and their use in the Italian diet. Mussels, filter feeder and sedentary organisms, were used in order to test water pollution whereas Norway lobster and red mullet (benthic fish) were used in order to test sediment pollution. The concentration of ?PCBs exceeded that of ?OCs in the samples analysed. The highest concentrations of ?PCBs (1415 ng/g lipid weight) and ?OCs (507 ng/g lipid weight) were found in pilchard while the lowest concentrations of the same pollutants were found in cephalopods. Our results have shown that species such as anchovy, pilchard and mackerel, were the most polluted due to their location at the last level of the trophic chain. All samples contained different concentrations of PCBs and among these, congeners 153 and 138 were the most representative. Among the OCs, except for the cuttle-fish, the highest concentrations were found for p,p(')-DDE and p,p(')-DDD that are metabolite of DDT. The prevailing DDE presence, compared to DDT (high DDE/DDT ratio), suggested that the biotransformation rate of pollutants was very efficacious in fish and above all in crustaceans. Results have also been interpreted in terms of geographical distribution and organisms' biological cycle. None of the samples analysed exceeded the tolerance limits established by the OCs Italian legislation.     

Polybrominated diphenyl ethers, polychlorinated naphthalenes and polycyclic musks in human fat from Italy: Comparison to polychlorinated biphenyls and organochlorine pesticides

Prior to this study, reports of occurrence of polycyclic musks and polychlorinated naphthalenes (PCNs) in human tissues from Italy were not available. In this study, concentrations of PCNs and polycyclic musks were determined in human adipose tissue from Italy collected during 2005-2006; for comparison, legacy organohalogen pollutants such as organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined. ΣPCN concentrations ranged from 0.5 to 14 ng/g lipid wt (lw). Polycyclic musks such as HHCB and AHTN were found in 92% and 83% of the human samples, respectively. Concentrations of PBDEs in Italian adipose tissue ranged between 3.2 and 35.6 ng/g lw.     

The variability of polychlorinated biphenyls levels in urban soils from five European cities

The concentration of PCBs in topsoils from five European cities was assessed and the highest levels were found in Glasgow (Scotland), followed by Torino (Italy), Aveiro (Portugal), Ljubljana (Slovenia) and Uppsala (Sweden). All cities showed the presence of local sources in addition to diffuse contamination from global atmospheric transport. The association of general soil parameters with PCBs in Glasgow and with heavier congeners in Torino and Ljubljana indicates that retention of these compounds is occurring. The profiles obtained resemble Aroclor 1254 and 1260, which are important local sources. Nevertheless, differences in PCB profiles were observed among cities, due to the combined effects of the age of the contamination (which determines the time available for volatilisation and degradation), different sources of PCBs and differences in climate (which influence volatilisation and deposition).     

Comparison of methods for the extraction and determination of polychlorinated biphenyls in shiphull antifoulings

A method is presented for the determination of PCBs in chlorinated rubber antifoulings. In ten different brands, no PCB concentrations above 0.5 mg kg^?1 were found.     

Physical factors negatively affecting evaluation of long-term biodegradation experiments of polychlorinated biphenyls

Behaviour of PCB added in the form of a technical mixture (Delor 106) and [¹⁴C]PCB 77 into different aqueous model cultivation media in long-term experiments was studied. The work was focused on monitoring PCB recovery from liquid media in the absence of micro-organisms. GC-ECD and radioanalysis were utilised for determination of PCB in the examined systems. Strong relations between duration of experiments, composition of media, degree of chlorination of biphenyls, and recovery of PCB were found. The lowest yields of PCB were observed for the extracts from model solutions based on N-limited cultivation media without veratryl alcohol and Tween 80. The addition of these components, mainly of Tween 80, caused a significant increase of PCB recoveries.     

Microbial transformation and degradation of polychlorinated biphenyls

This paper reviews the potential of microorganisms to transform polychlorinated biphenyls (PCBs). In anaerobic environments, higher chlorinated biphenyls can undergo reductive dehalogenation. Meta- and para-chlorines in PCB congeners are more susceptible to dechlorination than ortho-chlorines. Anaerobes catalyzing PCB dechlorination have not been isolated in pure culture but there is strong evidence from enrichment cultures that some Dehalococcoides spp. and other microorganisms within the Chloroflexi phylum can grow by linking the oxidation of H(2) to the reductive dechlorination of PCBs. Lower chlorinated biphenyls can be co-metabolized aerobically. Some aerobes can also grow by utilizing PCB congeners containing only one or two chlorines as sole carbon/energy source. An example is the growth of Burkholderia cepacia by transformation of 4-chlorobiphenyl to chlorobenzoates. The latter compounds are susceptible to aerobic mineralization. Higher chlorinated biphenyls therefore are potentially fully biodegradable in a sequence of reductive dechlorination followed by aerobic mineralization of the lower chlorinated products.     

Concentration levels and congener profiles of polychlorinated biphenyls, pentachlorobenzene, and hexachlorobenzene in commercial pigments

The concentration levels and congener profiles of polychlorinated biphenyls (PCBs), pentachlorobenzene (PeCBz), and hexachlorobenzene (HxCBz) were assessed in commercially available organic pigments. Among the azo-type pigments tested, PCB-11, which is synthesized from 3,3′-dichlorobendizine, and PCB-52, which is synthesized from 2,2′,5,5′-tetrachlorobendizine, were the major congeners detected. It is speculated that these were byproducts of chlorobendizine, which has a very similar structure. The total PCB concentrations in this type of pigment ranged from 0.0070 to 740 mg/kg. Among the phthalocyanine-type pigments, highly chlorinated PCBs, mainly composed of PCB-209, PeCBz, and HxCBz were detected. Their concentration levels ranged from 0.011 to 2.5 mg/kg, 0.0035 to 8.4 mg/kg, and 0.027 to 75 mg/kg, respectively. It is suggested that PeCBz and HxCBz were formed as byproducts and converted into PCBs at the time of synthesizing the phthalocyanine green. For the polycyclic-type pigments that were assessed, a distinctive PCB congener profile was detected that suggested an impact of their raw materials and the organic solvent used in the pigment synthesis. PCB pollution from PCB-11, PCB-52, and PCB-209 pigments is of particular concern; therefore, the monthly variations in atmospheric concentrations of these pollutants were measured in an urban area (Sapporo city) and an industrial area (Muroran city). The study detected a certain level of PCB-11, which is not included in PCB technical mixtures, and revealed continuing PCB pollution originating from pigments in the ambient air.     

Distribution of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and non-ortho coplanar polychlorinated biphenyls in river and offshore sediments

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and non-ortho chlorine substituted coplanar polychlorinated biphenyl (Co-PCBs, non-ortho Cl CBs) in river and offshore sediment samples were analyzed isomer-specifically using (13)C-labeled their respective internal standards and a selected ion monitoring method of high resolution gas chromatograph-mass spectrometry (GC-MS). These compounds were found in all samples analyzed. The average concentrations of the total PCDDs, PCDFs and Co-PCBs in the 23 sediment samples taken from rivers were 11 000, 1300 and 160 pgg(-1) of dry wt, respectively, those in six offshore sediments were 7600, 980 and 52 pgg(-1), respectively. The concentrations of Co-PCBs were much lower than those of PCDDs and PCDFs in all sediment samples. The magnitude of these concentrations was in the order of lower reach of river > offshore area > upper reach of river. The concentrations of PCDDs and PCDFs in the rural river were higher than those in the urban river, whereas the Co-PCB concentration in an urban river was six times higher than that in a rural river. The Co-PCB concentrations in the urban area and industrial area were higher than that in any other area. These findings suggest that the pollution by PCDDs and PCDFs was derived from some kinds of incinerations and herbicides applied in the past and that Co-PCB pollution was caused by PCB preparation used in the past in urban and industrial areas and by municipal waste incineration in urban areas.     

Organochlorine pesticides and polychlorinated biphenyls in Korean human milk: Contamination levels and infant risk assessment

The levels of persistent organic pollutants (POPs) were determined in 50 samples of Korean human milk. POPs include organochlorine pesticides (OCPs) [aldrin, chlordanes, dieldrin, dichlorodiphenyltrichloroethanes (DDTs), endrins, heptachlors, hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), mirex, and toxaphenes] and marker PCBs (PCB28, PCB52, PCB101, PCB138, PCB153 and PCB180). In all samples, p,p′-DDE were determined as 75.5–1115.3 ng/g fat. The compounds β-HCH and p,p’-DDT were detected at 72% and 60% of the samples, respectively. Chlordanes (nd–84.9 ng/g fat) heptachlors (nd–40.1 ng/g fat), HCB (nd–42.9 ng/g fat) and PCBs (nd–38.3 ng/g fat) were detected in several samples. The ratio of dichlorodiphenyltrichloroethylene (DDE)/DDT was 6.8, which explained that exposure of volunteers to DDT did not occur recently. Compared with the previous monitoring data, the level of marker PCBs generally decreased in the milk samples. The levels of OCPs are significantly correlated to the residential periods of the mothers but not with their dietary habits. Considering the daily intake of each OCPs, 18% of infants would ingest the amount of heptachlor exceeding the acceptable daily intake (ADI) proposed by World Health Organization (WHO). There was no sample surpassing the WHO ADI for DDTs, HCB and chlordanes.     

Background levels of non-ortho-substituted (coplanar) polychlorinated biphenyls in human serum of Missouri residents

This study characterizes the levels of polychlorinated biphenyls (PCB) congeners PCB 77, PCB 81, PCB 126, and PCB 169, in a group of 150 men and women with no documented exposure to PCBs. Its purpose is to provide current referent levels of coplanar PCBs in Missouri residents and to compare those levels to levels reported in the literature from the United States and other countries. Although this study used an extensive questionnaire assessing potential sources of exposure, no positive relations were found between these exposure sources and participants' PCB levels. The PCB levels for the four congeners measured were lower than any reported in the literature. PCBs 126 and 169 are only two of the dioxin-like congeners; however, their contribution makes up 11% of the total TEQ. Age was significantly related to PCB 126 and PCB 169. For every one-year increase in age, both PCB congeners increased by approximately 0.4 parts per trillion (ppt). There was no gender difference for PCB 126; however, PCB 169 levels were 3 ppt higher in males than females.     

Congener-specific accumulation of polychlorinated biphenyls in ovarian follicular wall follows repeated exposure to PCB 126 and PCB 153. Comparison of tissue levels of PCB and biological changes

OBJECTIVE: Small (SF), medium (MF) and large (LF) preovulatory porcine follicles were isolated and incubated in an Erlenmeyer flask containing 5 ml of medium with addition of PCB 126 or PCB 153 to test differences in their accumulation in the follicular wall. METHODS; The follicles were incubated in M199 medium at 37 degrees C with constant shaking at 70 rpm, for 6 days. The media were changed every day and repeated dose 25 pg/ml of PCB 126 or 25 ng/ml of PCB 153 was added each day till 6 days of culture. Media were collected every day and frozen for steroid analysis by RIA. 24 h after the last treatment follicles were frozen for further polychlorinated biphenyls (PCB) content analysis. PCB concentrations in the follicular wall were analysed by mass spectrometry. RESULTS: 3.3%; 3.6% and 5.6% of total PCB 126 dose, and 71%; 71.4% and 30.4% of total PCB 153 dose accumulated in SF, MF and LF follicles, respectively. The accumulative effect of PCB was manifested by the disruption of estradiol (E2) secretion. In SF antiestrogenic action of PCB 126 was observed during the whole time of exposure while PCB 153 decreased E2 till 4 days of culture and then estrogenic action was observed. In MF, both these congeners decreased E2 till 5 days of exposure and then estrogenic actions were noted with the highest magnification in the case of PCB 126. In LF both PCB studied increased E2 till 3 days of exposure with the highest magnification of PCB 126, then antiestrogenic action was noted. Testosterone secretion was generally affected in a pattern oposite to that of E2 suggesting action on P450arom activity. CONCLUSION: The results of these studies demonstrated that disruption of aromatization process in the follicles following repeated exposure to both congeners is not directly correlated with the bioaccumulation or amount of PCB within the follicular wall.     

Organochlorine pesticides and polychlorinated biphenyls in California sea lions

Concentrations of polychlorinated biphenyls (PCBs), DDTs, chlordanes, HCHs, hexachlorobenzene (HCB), dieldrin, heptachlor epoxide, tris(4-chlorophenyl)methane (TCPMe), and tris(4-chlorophenyl)methanol (TCPMOH) were measured in the blubber of California sea lions (Zalophus californianus) collected in 2000. DDTs were the most predominant contaminants, followed by PCBs, chlordanes, TCPMe, HCHs, TCPMOH, dieldrin, and heptachlor epoxide. Concentrations of PCBs and DDTs varied from a few microg/g to several hundreds of microg/g on a lipid weight basis. Concentrations of DDTs have declined by an order of magnitude over the last three decades in California sea lions; nevertheless, the measured concentrations of PCBs and DDTs in California sea lions are still some of the highest values reported for marine mammals in recent years. Concentrations of organochlorines were highly correlated with one another. Concentrations of PCBs and DDTs in the blubber of gray whale, humpback whale, northern elephant seal, and harbor seal, and in the adipose fat of sea otter, were lower than the levels found in California sea lions, and were in the range of a few to several microg/g on a lipid weight basis.     

Polychlorinated dibenzo-p-dioxins, dibenzofurans and polychlorinated biphenyls levels in human breast milk from different regions of Turkey

Human breast milk offers the optimal nutrition for all infants and have been widely used in biomonitoring programs to assess human exposure to lipophylic environmental contaminants such as polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF) and polychlorinated biphenyls (PCB). There are no previous reports from Turkey on chemically determined levels of PCDDs, PCDFs, and PCBs in human breast milk expressed as World Health Organization (WHO) toxic equivalents (TEQ). To get an overview of the levels of these contaminants in Turkish human milk, samples from 51 Turkish women living in the Ankara, İstanbul, Antalya, Kahramanmaraş, and Afyon provinces were analyzed by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) throughout 2007. The mean concentrations of WHO_PCDD/F-TEQ and WHO_PCB-TEQ of all samples from the five regions were 7.5 and 3.1 pg g⁻¹ on a lipid basis, respectively. PCDD/F concentrations ranged between 0.78 and 29.3 pg WHO-TEQ g⁻¹ fat (1.7 and 36.2 pg WHO-TEQ g⁻¹ fat, respectively, including PCB). Of the five studied locations, the lowest levels of ∑TEQs (PCDD/F + PCB) were found in the Afyon (6.8 pg WHO-TEQ g⁻¹ fat) and the highest in the Antalya (15.6 pg WHO-TEQ g⁻¹ fat) province. The results have been discussed in terms of regions and PCDD/F and PCBs for which analyses had been made. The mean levels of PCDD/Fs and PCBs in Turkish human milk are comparable to that found in other countries.     

Concentrations of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and non-ortho and mono-ortho polychlorinated biphenyls in blood of Yusho patients

We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho polychlorinated biphenyls (non-ortho PCBs) and mono-ortho polychlorinated biphenyls (mono-ortho PCBs) in blood collected from 279 Yusho patients living in Japan, 92 Yusho-suspected persons living in Japan and 127 normal controls living in Fukuoka Prefecture, and compared among the groups in terms the concentrations of these compounds. The total toxic equivalents (TEQ) concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in the bloods of Yusho patients and Yusho-suspected persons were 161.4 and 51.2 pg TEQ/g lipid, respectively and were about 3.5 and 1.1 times higher than those of normal controls, respectively. Although the TEQ concentrations of PCDDs, non-ortho PCBs, and mono-ortho PCBs among Yusho patients, Yusho-suspected persons and normal controls were nearly the same, the PCDFs levels of Yusho patients were significantly higher than those of Yusho-suspected persons and about 10.3 times higher than those of normal controls. In Yusho patients, PCDFs contributed about 65% to the total TEQ concentration. Among the PCDFs congeners for Yusho patients, the concentration of 2,3,4,7,8-pentachlorodibenzofuran (PeCDF) was about 11.3 times higher than that of normal controls. These findings indicated that Yusho patients even now, more than 34 years after the outbreak of Yusho, have much higher blood levels of 2,3,4,7,8-PeCDF in general than do unaffected persons.     

Recent levels of organochlorine pesticides and polychlorinated biphenyls in sediments of the sewer system in Hanoi, Vietnam

The occurrence, temporal trend, sources and toxicity of PCBs and organochlorine pesticides were investigated in sediment samples from the sewer system of Hanoi City, including the rivers Nhue, To Lich, Lu, Set, Kim Nguu and the Yen So Lake. In general, the concentrations of the pollutants followed the order DDTs > PCBs > HCHs (β-HCH) > HCB. However, the pollution pattern was different for the DDTs and PCBs when the sampling locations were individually evaluated. The concentrations of the DDTs, PCBs, HCHs, and HCB ranged from 4.4 to 1100, 1.3 to 384, <0.2 to 36 and <0.2 to 22 ng/g d.w., respectively. These levels are higher than at any other location in Vietnam. Compared to measurements from 1997, the DDTs, PCBs, β-HCH and HCB levels show an increasing trend with DDT/DDE ratios, indicating very recent inputs into the environment although these persistent compounds are banned in Vietnam since 1995.     

A practical approach to the degradation of polychlorinated biphenyls in transformer oil

A practical and efficient disposal method for hydrodechlorination of polychlorinated biphenyls (PCBs) in transformer oil is reported. Transformer oil containing PCBs was treated by nanometric sodium hydride (nano-NaH) and transition metal catalysts. High destruction and removal efficiency (89.8%) can be attained by nano-NaH alone under mild conditions. The process exhibits apparent characteristics of a first order reaction. The reductive ability of nano-NaH was enhanced by the addition of transition metal catalysts. In the presence of TiCl4, 99.9% PCBs was hydrodechlorinated. The complex reducing reagents, Ni(OAc)2+i-PrONa, show extra hydrodechlorinating activity for di-chlorinated biphenyls.