Polychlorinated biphenyls in the atmosphere of Taizhou,a major e-waste dismantling area in China

PM2.5, total suspended particles （TSP） and gas phase samples were collected at two sites of Talzhou, a major e-waste dismantling area in China. Concentrations, seasonal variations, congener profiles, gas-particle partitioning and size distribution of the atmospheric polychlorinated biphenyls （PCBs） were studied to assess the current state of atmospheric PCBs after the phase out of massive historical dismantling of PCBs containing e-wastes. The average ∑38PCBs concentration in the ambient air （TSP plus gas phase） near the e-waste dismantling area was （12,407 ± 9592） pg/m^3 in winter, which was substantially lower than that found one decade ago. However, the atmospheric PCBs level near the e-waste dismantling area was 54 times of the reference urban site, indicating that the impact of the historical dismantling of PCBs containing e-wastes was still significant. Tri-Penta-CBs were dominant homologues, consisting with their dominant global production. Size distribution of particle-bound PCBs showed that higher chlorinated CBs tended to partition more to the fine particles, facilitating its long range air transportation.

Occurrence and congeners specific of poiychlorinated biphenyls in agricultural soils from Southern Jiangsu, China

A total of 198 agricultural soil samples were collected from Zhangjiagang and Changshu in Southern Jiangsu for analysis of 13 polychlorinated biphenyls （PCBs） in order to assess the levels of pollution, sources, area distribution, and potential risk for the environment. All methods were rigorously tested and an adequate quality control was ensured. Only one site had no PCBs residues, and the highest total PCBs concentration in the surface soils was 32.83 ng/g. The average concentration in all the soil samples was 4.13 ng/g, signaling low-level pollution. Tetra-, penta-, and hexa-chlorinated biphenyls were dominant species in soil samples, accounting for more than 75% of ∑PCBs in the soil samples. PCB118 was the most abundant congener in all the samples. The PCB118 was about 20% of ∑PCBs. The soil organic matter content showed only a weak correlation with the levels of all PCB congeners, in which a better correlation was noted for the more volatile lighter PCB congeners than for the heavier homologues. To a certain extent, the sources and land use seemed to influence the levels of PCBs.

Levels and distributions of polychlorinated biphenyls in sewage sludge of urban wastewater treatment plants

Concentrations of polychlorinated biphenyls （PCBs） have been measured in sewage sludge samples from 8 urban wastewater treatment plants in Beijing, China. The PCB congeners were analyzed by isotope dilution high resolution gas chromatography/high resolution mass spectrometry method. The concentration of PCBs ranged from 65.6 to 157 ng/g dry weight （dw）, with a mean value of 101 ng/g dw. The dioxin-like PCB WHO-TEQs （World Health Organization-Toxic Equivalents） of the sludge were lower than 1 pg /g dw. Consequently, all the concentrations of PCBs in sludge samples were below the upper limit for land application according to the Chinese legislation law for agriculture use. The PCB homologue profiles in sludge samples were dominated by tri-CBs and tetra- CBs. Similar distributions have been found in one of the Chinese PCB commercial products. The patterns of dioxin-like and indicator congeners observed in this study were quite similar in all samples. The predominant congener for dioxin-like and indicator PCBs were PCB-118 and PCB-28, respectively, while PCB-126 had the highest TEQ value.

A QSRR Study on the Chromatographic Retention Indices of Hydroxylated Polychlorinated Biphenyls

Hydroxylated Polychlorinated Biphenyls （HO-PCBs） are the metabolite of polychlorinated biphenyls and have drawn much attention because they have hazard on human health and ecosystems. Molecular connectivity index calculation has been performed for 19 HO-PCB compounds. A number of statistically based parameters have been extracted. Linear relationship between chromatographic retention index （RI） and the molecular connectivity index of 15 compounds in the training set has been established by multiple linear regression method. The other 4 HO-PCBs are used as the external test set. The result shows that the parameters can be well used to express the quantitative structure-retention relationship （QSRR） of HO-PCBs. Good stability and predictive ability have been demonstrated by leave-one-out cross-validation and the external test set.

Photolysis of mono- through deca-chlorinated biphenyls by ultraviolet irradiation in n-hexane and quantitative structure-property relationship analysis

The photolysis of 16 polychlorinated biphenyls （PCBs） （including mono- through deca-chlorinated） in n-hexane was investigated under ultraviolet irradiation using a 500-W high-pressure mercury lamp. Photolysis of PCBs follows pseudo-first-order reaction kinetics, with photolysis rate constants ranging between 0.0011 s^-1 for PCB-52 and 0.0574 s^-1 for PCB-118. The degradation rates of PCBs by high-pressure mercury lamp irradiation were remarkably independent with respect to the degree of chlorination. Furthermore, partial least squares （PLS） models were developed to provide insight into which aspect of the molecular structure influenced PCB photolysis rate constants. It was found that the photolysis rates of PCBs increased with an increase in the net charge on the carbon atom （qc）, （ELUMO-EHOMO）^2, and the Y-axis dipole moment （μy） values, or the decrease in the energy of the second highest occupied molecular orbital （EHOMO-1）, energy of the lowest unoccupied molecular orbital （ELUMO）, ELUMO ＋ EHOMO, ELUMO - EHOMO, most positive atomic charge （q^＋）, and the twist angle of the chlorine atom （TA） values.

Spatial Distribution of Polychlorinated Biphenyls(PCBs)Contaminants in the Tidal-flat Sediments of Yangtze Estuary

PCBs pollutants are measured on tidal-flat sediments of Yangtze estuary by a high resolution capillary column gas chromatography ( HP6890 ) equipped with an 63Ni electron capture detector ( ECD ). The concentration tendency of PCBs is Phragmites zone > Scirpus zone > bare mudflats. There are linear relations between PCBs and TOC and > 63μm grain size percentage ( in volume ). The low chlorinated congeners may be more important than the high chlorinated congeners in this area. PCBs prefer to accumulate in the sediments near sewage outlets and Phragmites zone. The sediments’ PCBs pollution ( 10.7 ~ 28.6 ng/g, dry weight ) in the Yangtze estuary tidal-flat is less serious than that of the most of other areas in the world .But the detected ratio is 100%, even the Jiuduansha shoal has detected PCBs, so much attention should be paid to this area for PCBs.

Effect of polychlorinated biphenyls on spermatogenesis and testosterone secretion in adult cocks

The effects ofpolychlorinated biphenyls (PCBs) on reproduction of adult cocks were studied by gavaging peanut oil or PCBs (Aroclor 1254, 50 mg/kg) once a week for six consecutive weeks. Physiological parameters were recorded and gonads were removed at the end of experiment for histological examination. The results showed that there was no significant difference between the control and treatment group in body weight, respiration rate, heart rate, body temperature, and the numbers of red and white blood cells. However, there was a marked decrease in the testicular weight and serum testosterone level after PCB treatment. Morphological studies manifested severe damage of the seminiferous tubules by PCB. The number of the germ cells at the different developmental stages was decreased and condensed nuclei were observed in most of these cells. This study revealed that the reproductive function of the adult cocks is sensitive to PCBs, which inhibited mainly spermatogenesis and testosterone secretion.

Polystyrene nanoplastics aggravated ecotoxicological effects of polychlorinated biphenyls in on zebrafish(Danio rerio)embryos

In view of the accumulation of nanoplastics(NPs)in the food chain of environment and animals,and the good adsorption properties of nano-plastics to toxic substances,it is necessary to explore the influence of NPs in living organisms.In this study,single and joint toxicological effects of polystyrene nanoplastics(PS-NPs,size 80 nm)and polychlorinated biphenyls(PCBs),were explored in freshwater aquatic animal model zebrafish(Danio rerio).Our study found that exposure to single PS-NPs induced mild acute toxicity,albeit the combined exposure of PS-NPs and polychlorinated biphenyls aggravated the toxicity of PCBs in a dose-dependent manner.Results from gene expression profiling showed that NPs exposure could activate detoxification process,resulting in a slight up-regulation of antioxidant genes(sod1,gstp1),bone development genes(bmp2,bmp4)and cardiac gene(tbx20);while PCBs suppressed the detoxification through down-regulation of these genes,and the addition of NPs will exacerbate the impact of PCBs on gene suppression.Importantly,the results of in vivo purification experiments found that NPs showed prolonged retention in liver,intestine and gills of zebrafish and they might have crossed biological barrier and accumulate in lipid-rich tissues and excretion does not appear as the significant pathway for their elimination.In conclusion,the toxic effects of polychlorinated biphenyls on chorionic protected embryos were not significant as zebrafish chorion plays an important role in resisting the invasion of pollutants;PCBs can seriously damage the bone and heart development of zebrafish,while the presence of NPs significantly enhanced the toxicity of PCBs in zebrafish,which is an alarming concern for growing NPs levels and ecological safety in aquatic environment.

Development and characterization of new polyclonal antibodies specific for three polychlorinated biphenyls

Three polychlorinated biphenyls （PCBs） congeners and their corresponding haptens bearing four carbon length carboxylic groups that can be linked to a protein for raising antibodies were synthesized. The three resultant immunogens were fabricated and used to stimulate immune responses in rabbits to survey the characteristics of the haptens. Three of the resultant polyclonal antibodies （Pabs） were obtained. The antiserum exhibited relatively high antibody titres （1：32-64） in double agar diffusion.

Levels of polychlorinated biphenyls in 1,4-dichlorobenzene mothballs

Although polychlorinated biphenyls(PCBs) are globally recognized pollutant, an understanding of their resources as by products in chemical industry is poorly investigated. This paper presents data from a study that was conducted in order to determine the extent of PCBs in 1,4 dichlorobenzene( p DCB) mothballs. Total PCBs and dioxin like PCBs were detected in five mothball samples. Total PCB concentrations ranged from 328 ng/g to 1798 ng/g, while the levels of WHO TEQ were between 0 16 pg/g and 13 pg/g. Mean concentrations of total PCBs and WHO TEQ in the samples were 724 ng/g and 3.2 pg/g, respectively. The highest level of PCB congeners was that of trichlorinated biphenyls(537 ng/g), which maybe due to the relatively low chlorination in the process of p DCB production. A mechanism of the formation of PCBs from polychlorinated benzene in the presence of chlorine is also suggested. The results suggested that re estimation on the risk of p DCB products, especially the products for daily use such as mothballs, is expected.

Prediction of the Aqueous Solubilities of Polychlorinated Biphenyls

Using the molecular electronegativity distance vector descriptors derived directly from the molecular topological structures, the aqueous solubilities of polychlorinated biphenyls (PCBs) were predicted. A three-variable regression equation with correlation coefficient of 0.9739 and the root mean square errors of 0.26 was developed. The descriptors included in the equation represent three interactions between three pairs of atomic types, i.e., atom -C= and >C=, -C= and -Cl, and -Cl and -Cl. It has been proved that the aqueous solubilities of 137 PCB congeners can be accurately predicted as long as there are more than 65 calibration compounds.

Polychlorinated Biphenyls Contamination of Sludge in India

Polychlorinated Biphenyls (PCBs) exist in all compartments of the ecosystem due to wide industrial applications and production during burning processes. The PCBs congeners were quantified in the industrial, municipal and agricultural wastes of the most industrialized area of the country, Raipur city, India. The concentration of ΣPCBs in the sludge, sewage and agriculture wastes (n = 4) was ranged from 497 - 800 μg/kg with mean value of 634 ± 146 μg/kg. The PCBs congeners detected in the waste materials were ranged from 56 - 85 with mean value of 75 ± 13. The highest number of congeners was quantified in the sludge materials due to the existence of the heavy PCBs. The PCBs congeners were found to decrease vertically due to the adsorption by the geo-media. The distribution, sources and toxicities of PCBs congeners in the waste materials are discussed.

Treatment of Materials Contaminated with Polychlorinated Biphenyls(Pcbs):Comparison of Traditional Method and Supercritical Fluid Extraction

The objective of this study was to develop an experimental methodology for the extraction of polychlorinated biphenyls (PCBs) from contaminated soil and wood material using the Soxhlet extraction method and supercritical fluid technology. The sample PCB contents were quantified using Gas Chromatography-Mass Spectrometry (GC/MS). Conventional extractions of PCBs from soil samples showed higher extraction yields for samples with the highest initial PCB levels and longest extraction times. Specific PCBs yielded 74.0% - 78.3% removal using ethanol as the solvent. 91.0% - 94.3% removal of the total PCB content was achieved using hexane as the solvent. Supercritical fluid extraction of soil samples resulted in 50.0% - 70.5% removal for specific PCBs and 57.3% removal of the total PCB content. For wood, the use of Soxhlet extraction resulted in 87.0% - 94.0% removal for specific PCBs and 95.0% - 96.3% removal of the total PCB content. Supercritical fluid extraction of wood samples resulted in 91.1% - 95.0% removal of specific PCBs and 95.1 % of the total PCB content.

Optimization of Gas Chromatography-electron Ionization-tandem Mass Spectrometry for Determining Toxic Non-ortho Polychlorinated Biphenyls in Breast Milk

One of the most commonly used non-invasive methods for assessing human exposure to pollution is the analysis of human milk.Human milk analyses help estimate the exposure of infants[1].This is why breast milk is receives scientific interest,and various methods for determining different pollutants from the environment are being developed[2,3].

Bioaccumulation of polychlorinated biphenyls in prawns and a mud crab from mixed-aquaculture ponds

The bioaccumulation of ten polychlorinated biphenyl （PCB） congeners was investigated within different tissues in three prawns （Penaeusorientalis Kishinouce, Laomedia astacina de Haan and Penaeus vannamei Boone） and one mud crab （Scylla serrata Forsskal） from mixed-aquaculture ponds in Taizhou in April 2007. The average concentrations （wet mass） of ∑ PCBs in muscle, head, and rind tissues for mean among these prawn species were 7.04, 21.16, and 11.47 ng/g, respectively. The average concentrations of ∑ PCBs in muscle, branchia, and spawn in Scylla serrata were 6.49, 21.13, and 19.76 ng/g, respectively. The concentrations of CB28 were the highest in prawn tissues （2.40 ng/g）, and accounted for 18.60% of ∑ PCBs. The concentration of CB52 was the lowest. The application of principal component analysis （PCA） for the estimation of PCB sources of contamination resulted in first component main contributions of CB101, CB153 and CB28 in the muscle, head, and rind in combined prawn samples, respectively. The enrichment level of PCBs for different tissues varied greatly. The accumulation coefficient of ∑ PCBs in prawn muscle, head, and rind tissues were 396.35, 1 191.79, and 645.91, respectively. For the Scylla serrata, the accumulation coefficients were 365.81, 1 190.50, and 1 113.31 for muscle, branchia, and spawn tissues, respectively. For prawns, the accumulation coefficient of CB153 was the highest in muscle tissues, while CB155 had the highest coefficients in the head and rind tissues. The CB155 coefficient was the highest in spawn tissues of the mud crab.

Residues of Polychlorinated Biphenyls (PCBs) in Fish, Water and Sediment from Shing Mun River

The level and pattern of contamination by polychlorinated biphenyls (PCBs) were investigated in tilapia, Oreochromis mossambicus (Peters), sediment, and water from the Shing Mun River. The range of total PCBs was 12.9 ng/g to 181.6 ng/g wet weight in tilapia, 12.7 ng/g to 46.0 ng/g freeze-dried weight in sediment, and 3.8 ng/L to 13.6 ng/L in water. The effect of biomagnification was also observed, PCB concentrations increased from water to sediment to tilapia. PCB congeners occurred in such a way that lower chlorinated PCBs comprised a higher fraction of the total PCBs in water, sediment, and tilapia muscle, whereas higher chlorinated PCBs were more commonly found only in tilapia.

Using GC to determinate polychlorinated biphenyls in soil after pretreated with microwave-assisted alkaline degradation method

A new and simple microwave-assisted alkaline degradation （MAAD） method for the elimination of organoehlorine-pesticide interference on the determination of polychlorinated biphenyls （PCBs） in soil by GC is presented. Under the optimal conditions, the interference of α- HCH, β- HCH, γ -HCH,δ -HCH, o. p＇ - DDT, p. p＇ - DDD and p. p＇ - DDT could be eliminated completely, and p. p＇ - DDE, Aldrin and Dieldrin could be partially eliminated; however, Dieldrin could be completely eliminated by using concentrated sulphurie acid. The method was evaluated by analyzing the spiked-soil sample. The mean recovery obtained was 84. 1% and the Relative Standard Deviation （RSD） was 2. 7%. Experimental results also indicate that the degradation of the interference and the extraction of the target analytes, PCBs, could be carried out simuhaneously. Compared with the traditional methods, the MAAD method is a rapid, efficient and solvent-saving method,

Modification by Polychlorinated Biphenyls(PCBs)of Cadmium Induced Lesions in the Planarian Model,Dugesia dorotocephala

The appearance of abnormal growths on the planarian, Dugesia dorotocephala, in response to cadmium with and without pre-exposure to L-buthionine-R, S-sulfoximine (BSO) and concurrent exposure to the polychlorinated biphenyls (PCBs) Aroclor 1254, PCB 28, PCB 110 or PCB 126 is described. Pigmented rose thorn (PRT) lesions were non-invasive and appeared in response to PCBs. Post-head (PH) lesions developed in up to 100% of the animals within 6-20 days post-dosing, progressed rather rapidly and were highly invasive. Round tail tip (RTT) lesions appeared in lower frequencies within 10-30 days, but progressed extremely rapidly resulting in tail loss within 48 h. We have referred to these types of lesions as 'tumors', but they are not necessarily characteristic of vertebrate neoplasms.PCBs interacted with cadmium in a complex way, in some cases increasing total lesions and decreasing time-to-lesion and in other cases having the opposite effects. A three-factor (PCB, PCB dose, Cd dose) nested analysis of variance model was used to determine lesion rates in order to compare PCB potencies as potentiators or antagonists. The Aroclor mixture was always the least potent co-toxicant but appeared to be the most potent antagonist; the coplanar PCB 126 was the most potent co-toxicant. The complex response surfaces and the lack of stoichiometry in dose-response relationships indicate that multiple mechanisms are responsible for PH and RTT lesions in planarians. These results emphasize the complexity of PCB toxicities and suggest further studies to validate the planarian model as a screen for combinations or environmental mixtures which may have altered biological potency in other species.

Development of Different Strategies for the Clean-Up of Polychlorinated Biphenyls (PCBs) Congeners Using Pressurized Liquid Extraction

The extracted fish samples (w/w) using pressurized liquid extraction (PLE) were cleaned up by applying different adsorbent materials such as: combination of acidic/ basic silica and alumina, florisil, and silica gel either alone or in combination with another sort of sorbent. Different solvents such as hexane (H), dichloromethane (DCM), with different compositions were used to elute the PCBs target compounds from the spiked fish samples. Overall the mean percentage recoveries for all PCBs congeners using PLE were ranging from 78.6% to 98.7%;from 79.4% to 91.8%;from 65.8% to 104.5% and from 82.4% to 100.9% for cases A, B, C, D and E, respectively. However, the overall mean percentage recoveries for the 13C-PCBs surrogate including: 101, 138, 153, 180 and 209 were ranging from 88.2% to 97.6%;from 79.4% to 90.2%, from 88.3% to 96.4%, from 79.8% to 90.4% and from 83.9% to 95.9%, for cases A, B, C, D and E, respectively. The limits of detection of the proposed method were varied from 0.01 to 0.28 ng/g (w/w) for different PCBs congeners. The proposed method has linear dynamic range from 21.5 ng/g to 109 ng/g. This method was applied to fish samples for the determination of the target PCBs components.

Removal of Pesticides and Polychlorinated Biphenyls from Municipal Wastewater by Reed Beds in A Constructed Wetland

Constructed wetlands containing reed beds are believed to facilitate the removal from water of various toxic substances, such as polychlorinated biphenyls （PCBs）, pesticides and herbicides, as these substances partition strongly to organic particulate matter. In order to evaluate this premise, the study investigated the organic matter, pesticides and PCBs content in wastewater and in soil within the reed beds, in their entry, middle, and exit-part areas in a full-scale operating subsurface-flow （SSW） constructed wetland （CW） in Poland. It is found that chlorinated pesticides such as 2,4＇dichlorodiphenyltrichloroethane （2,4＇DDT）, 4,4＇dichlorodiphenyldichloroethylene （4,4＇DDE）, hexachlorobenzene （HCB）, as well as PCBs in the wastewater. In the entry-part area of reed beds, nearly all of the pesticides and PCBs content in the wastewater had been removed by soil. The level of contamination by these compounds declined with increasing distance from the point of discharge of the wastewaters into the reed beds, as well as downwards through the soil profile from the surface into the deeper layers. Vertical distributions of pesticides and PCBs content were proportional to the organic carbon content in the soil. It is therefore concluded that reed beds act as a trap for pesticides and PCBs, and thus can provide a very effective mechanism for their removal from wastewater.