-
Environmental Technology Oct 2023Bioremediation of sediment organic pollution has been intensely investigated, but the degradation of complex organic compounds, pesticide residues, and polychlorinated...
Bioremediation of sediment organic pollution has been intensely investigated, but the degradation of complex organic compounds, pesticide residues, and polychlorinated biphenyls (PCBs) remains poorly studied. In this study, sediments were collected from Zhanjiang Mangrove Reserve and inoculated in an inorganic salt medium using only biphenyl (BP) and PCBs as the carbon sources to obtain a PCB-degrading strain. A gram-negative bacterium that metabolized PCBs was isolated and identified as Lw3 by 16S rDNA phylogenetic analysis. Genomic sequencing showed that this bacterium possessed genes related to BP/PCB degradation, and its GC content was 58.2%; we identified 3326 cellular pathways. Gas chromatography-mass spectrometry was employed to test the PCB degrading ability; the results showed that the strain had a good degradation effect on PCB3 at concentrations of 5, 10, 20, 40, and 60 mg/L and that the final degradation rate was higher than 97% after 96 h. Interestingly, this strain showed good biodegradability of PCBs despite having no classical PCB degradation pathway, providing a new direction for research with practical significance for bioremediation of PCB contamination. Overall, this study provides valuable insights into the genetic structure of PCB-degrading strains as well as eco-friendly and low-cost PCB degradation and lays a foundation for the discovery of new degradation pathways.
Topics: Polychlorinated Biphenyls; Phylogeny; Biodegradation, Environmental; Genes, Bacterial; Genomics
PubMed: 35441572
DOI: 10.1080/09593330.2022.2068381 -
Nihon Rinsho. Japanese Journal of... Dec 2000Dioxins include polychlorinated dibenzo-p-dioxins(PCDDs), polychlorinated dibenzofurans(PCDFs), and part of polychlorinated biphenyls(PCBs). Only the compounds that are... (Review)
Review
Dioxins include polychlorinated dibenzo-p-dioxins(PCDDs), polychlorinated dibenzofurans(PCDFs), and part of polychlorinated biphenyls(PCBs). Only the compounds that are chlorinated at the 2,3,7, and 8 positions have characteristic dioxin toxicity. PCDDs, PCDFs and PCBs accumulate in the food chain due to their high lipophilicity, high stability, and low vapor pressure. They are not metabolized easily, however their hydroxylate are detected in feces. PCBs and dioxins cause a wide range of endocrine disrupting effects in experimental animals, wildlife, and humans. Endocrine related effects of PCBs and dioxins on thyroid hormones, neurodevelopment and reproductive development are summarized. In addition, some studies of exposure and endocrine-related effects in human populations are presented.
Topics: Animals; Chemical Phenomena; Chemistry, Physical; Dioxins; Endocrine System; Environmental Pollutants; Humans; Learning; Polychlorinated Biphenyls; Reproduction
PubMed: 11187731
DOI: No ID Found -
Environmental Science & Technology Mar 2023Polychlorinated biphenyl compounds (PCBs) are highly toxic organic chemicals still prevalent in the environment. While global inventories of the use and emissions of...
Polychlorinated biphenyl compounds (PCBs) are highly toxic organic chemicals still prevalent in the environment. While global inventories of the use and emissions of PCBs have been developed, estimates for individual countries determined using bottom-up approaches are few and often show different trends from the global inventory. Here, we determine the past, present, and future consumption and emissions of PCBs in India. A mass balance model was used to estimate middle (low-high) emissions in the period 1950-2100. Up to 7296 tonnes of PCBs have been used in transformers. PCBs imported as wastes are estimated to be approximately 5000 (2400-9100) tonnes. Total emissions from the use and disposal of transformers, industrial processes, and imported waste disposal are estimated to become 13 (0.1-537) tonnes, 89.26 (0.5-178) tonnes, 63 (3-910) tonnes, respectively, in the period 1950-2100. Congener-specific emissions are relatively high for low-chlorinated PCBs (-8, 18, 28, 31, 52, 101, 110, 118, 153, range: 0.1-118 tonnes). We find that industrial emissions are becoming important sources of PCBs and may become predominant, depending on emission scenarios.
Topics: Polychlorinated Biphenyls; Environmental Monitoring; Biphenyl Compounds; Refuse Disposal; India
PubMed: 36926860
DOI: 10.1021/acs.est.2c09438 -
Environmental Pollution (Barking, Essex... Oct 2021While polychlorinated biphenyl (PCB)-related risks have been reported at the cellular, organ, and individual levels in some marine mammals, studies quantifying the...
While polychlorinated biphenyl (PCB)-related risks have been reported at the cellular, organ, and individual levels in some marine mammals, studies quantifying the PCB-associated population-level effects are limited. Here, we combined chemical analysis and individual-based model simulation to investigate the impact of PCBs on the Indo-Pacific humpback dolphin (sub)population from the Pearl River Estuary (PRE). An annual PCB accumulation rate of 0.29 ± 0.07 mg/kg lipid per year was estimated based on the measured age-specific male data as males continue to accumulate PCBs throughout their lifetime, without depurating contaminant loads. Using the Taiwan Strait dolphin population with low PCBs as a baseline, we compare our model simulations in PRE population to estimate relative population impacts of PCBs and other stressors. When using the current vital rates of the PRE dolphins which have been affected by PCBs and other stressors (e.g., underwater noise, prey limitation, etc.), our simulations revealed a substantial decline (8.1%) in the annual population growth rate (λ) of PRE metapopulation compared to baseline over the next 100 years. At the estimated PCB accumulation rate, the PCB-mediated effects on calf survival and immunity would cause a slight decline (0.9%) in λ relative to baseline. Our findings suggest a relatively limited impact of PCBs on the long-term survival of PRE dolphins among all stressors. However, it should be noted that even under model simulations where dietary PCBs were eliminated, humpback dolphins would still need a long time to reduce their PCB burdens to a relatively "safe" level through biological cycling. Considering that the baseline vital rates might also have been affected by PCBs and other stressors, our results are considered relative rather than absolute. This study provides a starting point for quantifying population-level consequences of contaminant exposure on humpback dolphins, although more efforts are needed to perfect this type of analysis.
Topics: Animals; Dolphins; Ecosystem; Estuaries; Male; Polychlorinated Biphenyls; Water Pollutants, Chemical
PubMed: 34119862
DOI: 10.1016/j.envpol.2021.117544 -
Markers of polychlorinated biphenyl (PCB) degradation in highly contaminated soil of Central Russia.Environmental Science and Pollution... Oct 2020The highly polychlorinated biphenyl (PCB)-contaminated historical soil is located in the Serpukhov region (Central Russia). This study evaluates the processes of PCB...
The highly polychlorinated biphenyl (PCB)-contaminated historical soil is located in the Serpukhov region (Central Russia). This study evaluates the processes of PCB degradation in the soil under natural conditions. Compositions of industrial mixtures (Sovol, Sovtol, and trichlorodiphenyl) were compared with PCB-contaminated soil from different depths. An increased number of dichlorobiphenyls (6 congeners) were determined in the deeper soil horizons (40-60 cm) in comparison with the surface layer (1 congener). Non-associated with industrial mixture congener, PCB 11 was determined in some soil layers with concentrations reaching 3.6 mg/kg. PCB 11 can be considered as a potential marker of activated degradation processes in highly contaminated soils with industrial mixtures. Aegopodium podagraria reduced total PCB concentrations in the contaminated soil to 25% during pot experiments. Prospective precursors of PCB 11 were significantly depleted (62-88%) after phytoremediation, but this did not increase PCB 11 concentration in the soil.
Topics: Biodegradation, Environmental; Polychlorinated Biphenyls; Prospective Studies; Russia; Soil; Soil Pollutants
PubMed: 32564313
DOI: 10.1007/s11356-020-09712-1 -
Environment International May 2004Polychlorinated biphenyls including coplanar congeners were measured in the liver of different species of skates and ghostsharks. The mean concentrations of PCBs in...
Polychlorinated biphenyls including coplanar congeners were measured in the liver of different species of skates and ghostsharks. The mean concentrations of PCBs in skates (314 ng/g wet wt) were comparable with those in ghostsharks (285 ng/g wet wt). The specific analysis of PCB congeners in skates hepatic tissue revealed a profile dominated by hexa-, penta-, and heptachlorinated congeners followed by trichlorobiphenyls, tetra- and decachlorobiphenyls. A different profile dominated by hexa-, tri-, and pentachlorinated congeners, followed by heptachlorobiphenyl and decachlorobiphenyls was found in ghostsharks liver. The estimated 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs) of coplanar PCBs in skates and ghostsharks were 0.48 and 0.33 pg/g wet weight, respectively, with mono-ortho congeners PCB105, 118 and 156 contributing more than 90% to the TEQs.
Topics: Animals; Environmental Monitoring; Environmental Pollutants; Mediterranean Sea; Polychlorinated Biphenyls; Sharks; Skates, Fish; Tissue Distribution
PubMed: 14987864
DOI: 10.1016/j.envint.2003.07.002 -
Environmental Science and Pollution... May 2014To analyze the effect of polychlorinated biphenyl (PCB) 118 on fish bone metabolism, we examined osteoclastic and osteoblastic activities, as well as plasma calcium...
To analyze the effect of polychlorinated biphenyl (PCB) 118 on fish bone metabolism, we examined osteoclastic and osteoblastic activities, as well as plasma calcium levels, in the scales of PCB (118)-injected goldfish. In addition, effect of PCB (118) on osteoclasts and osteoblasts was investigated in vitro. Immature goldfish, in which the endogenous effects of sex steroids are negligible, were used. PCB (118) was solubilized in dimethyl sulfoxide at a concentration of 10 ppm. At 1 and 2 days after PCB (118) injection (100 ng/g body weight), both osteoclastic and osteoblastic activities, and plasma calcium levels were measured. In an in vitro study, then, both osteoclastic and osteoblastic activities as well as each marker mRNA expression were examined. At 2 days, scale osteoclastic activity in PCB (118)-injected goldfish increased significantly, while osteoblastic activity did not change significantly. Corresponding to osteoclastic activity, plasma calcium levels increased significantly at 2 days after PCB (118) administration. Osteoclastic activation also occurred in the marker enzyme activities and mRNA expressions in vitro. Thus, we conclude that PCB (118) disrupts bone metabolism in goldfish both in vivo and in vitro experiments.
Topics: Animals; Bone Resorption; Goldfish; Osteoblasts; Osteoclasts; Polychlorinated Biphenyls; Water Pollutants, Chemical
PubMed: 23247518
DOI: 10.1007/s11356-012-1347-5 -
The Analyst May 2020In this work, we demonstrated an ultrasensitive detection platform for polychlorinated biphenyls (PCBs) based on DNA microcapsules and a nonlinear hybridization chain...
In this work, we demonstrated an ultrasensitive detection platform for polychlorinated biphenyls (PCBs) based on DNA microcapsules and a nonlinear hybridization chain reaction (NHCR). In the process, first, electrochemical signal molecules (Methylene Blue, MB) were sealed in the prepared DNA microcapsules. In the presence of PCB-72, DNA microcapsules could be dissociated with the conjugation of the aptamer and target, and meanwhile, the released DNA strand could initiate the NHCR and trigger the chain branching growth of DNA dendrimers. Because the released MBs were intercalated into the DNA dendrimer, enhanced electrochemical responses could be detected. This method exhibited ultrahigh sensitivity to PCB-72 with a detection limit of 0.001 ng mL-1. Furthermore, the present aptasensor was also capable of discriminating different PCB congeners. Therefore, the devised label-free and enzyme-free amplification electrochemical aptasensor strategy has great potential for the detection of PCB-72 in real samples, and this strategy may also become an attractive alternative for sensitive and selective small molecule, protein, nucleic acid and nuclease activity detection.
Topics: Aptamers, Nucleotide; Biosensing Techniques; Capsules; DNA; Electrochemistry; Limit of Detection; Methylene Blue; Nucleic Acid Amplification Techniques; Nucleic Acid Hybridization; Polychlorinated Biphenyls
PubMed: 32334417
DOI: 10.1039/d0an00065e -
Integrated Environmental Assessment and... May 2019Contaminant remediation decisions often focus on sediment-organism relationships, omitting the partitioning between sediment and water that exists across a given site....
Contaminant remediation decisions often focus on sediment-organism relationships, omitting the partitioning between sediment and water that exists across a given site. The present study highlights the importance of incorporating nonsedimentary routes of exposure into a nonequilibrium, steady-state food web bioaccumulation model for predicting polychlorinated biphenyl (PCB) concentrations in benthic invertebrates. Specifically, we examined the proportion of overlying water relative to the sediment porewater respired by benthic invertebrates, which has been used in previous studies to examine contaminant bioaccumulation. We evaluated the model accuracy using paired benthos-sediment samples and an extensive fish contamination database to ensure realistic predictions at the base of the Detroit River (Ontario, Canada, and Michigan, USA) food web. The results demonstrate that, compared with empirical regression analyses, the food web bioaccumulation model provided satisfactory estimates of PCB bioaccumulation for benthos simulations and better estimates for fish simulations. Our results showed that PCB bioaccumulation measurements are significantly affected by variations in pollutant uptake and elimination routes via the overlying water, which in turn are affected by the degree of disequilibrium of PCBs between sediments and water. Interestingly, we obtained contrasting results regarding the effectiveness of remediation strategies for reducing the contaminant burden of the aquatic biota based on different proportions of overlying water relative to porewater. These differences could consequently impact decisions about the approaches for source control and strategic sediment remediation. This study suggests that bioaccumulation assessments could be improved through better identification of chemical uptake-elimination routes in benthos and by accounting for chemical bioavailability in sediment and water components in areas with disequilibrium.Integr Environ Assess Manag 2019;00:000-000. © 2019 SETAC.
Topics: Animals; Environmental Exposure; Environmental Monitoring; Fishes; Food Chain; Geologic Sediments; Invertebrates; Michigan; Models, Biological; Ontario; Polychlorinated Biphenyls; Rivers; Water Pollutants, Chemical
PubMed: 30675769
DOI: 10.1002/ieam.4130 -
Environmental Science & Technology Mar 2015It is well-known that absorption, distribution, metabolism, and excretion (ADME) processes in fish can alter polychlorinated biphenyl (PCB) congener patterns in fish,...
It is well-known that absorption, distribution, metabolism, and excretion (ADME) processes in fish can alter polychlorinated biphenyl (PCB) congener patterns in fish, but these patterns have never been investigated using an advanced source-apportionment tool. In this work, PCB congener patterns in freshwater fish were examined with positive matrix factorization (PMF). PCB congeners were quantified via EPA Method 1668 in fillet and carcass of six species in four study areas in the Columbia River near the Hanford Site. Six factors were resolved with PMF2 software. Depletion and enhancement of PCB congeners in factors, relative to Aroclor 1254, suggested biotransformation (via cytochrome P450) and bioaccumulation in fish, respectively. Notable differences were observed among species and across study locations. For example, sturgeon and whitefish exhibited congener patterns consistent with Aroclor weathering, suggesting potential PCB metabolism in these species. In terms of location, average concentration of total PCBs for all species combined was significantly higher (P < 0.05) at Hanford 100 and 300 areas, relative to upriver and downriver study sites. Furthermore, a distinct PCB signature in sturgeon and whitefish, collected at Hanford study areas, suggests that Hanford is a unique PCB source.
Topics: Animals; Body Burden; Environmental Monitoring; Fishes; Muscles; Polychlorinated Biphenyls; Rivers; Water Pollutants, Chemical
PubMed: 25621866
DOI: 10.1021/es504961a