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Mora M, Walker TR, Willis R. Spatiotemporal characterization of petroleum hydrocarbons and polychlorinated biphenyls in small craft harbour sediments in Nova Scotia, Canada. MARINE POLLUTION BULLETIN 2022; 177:113524. [PMID: 35279547 DOI: 10.1016/j.marpolbul.2022.113524] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 02/23/2022] [Accepted: 02/27/2022] [Indexed: 06/14/2023]
Abstract
Previous characterization of polycyclic aromatic hydrocarbons (PAHs) and metals has been conducted in small craft harbour (SCH) sediments in Nova Scotia, Canada, but petroleum hydrocarbons (PHCs) and polychlorinated biphenyls (PCBs) have not been spatiotemporally assessed. This study characterized the distribution of over 500 PHCs and PCBs samples in 31 SCHs sediments between 2000 and 2017. Federal and regional sediment quality guidelines were used to determine exceedances. Results showed exceedances for diesel and oil resembling PHCs, expected given their longer permanence in sediments and lower volatility. However, only 7% of the samples exceeded 500 ppm, threshold where benthic impairment is observed, showing low risk. PCBs do not pose high risk to biota since only six samples exceeded the higher effect level and 25% of them exceeded the lower effect one. Monitoring is recommended for SCHs with significant exceedances, as well as collectively assessing all contaminants characterized in SCHs.
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Affiliation(s)
- Myriam Mora
- School for Resource and Environmental Studies, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
| | - Tony R Walker
- School for Resource and Environmental Studies, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Rob Willis
- Dillon Consulting Limited, Halifax, Nova Scotia B3S 1B3, Canada
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2
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Halfadji A, Portet-Koltalo F, Touabet A, Le Derf F, Morin C, Merlet-Machour N. Phytoremediation of PCB: contaminated Algerian soils using native agronomics plants. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2022; 44:117-132. [PMID: 34355306 DOI: 10.1007/s10653-021-01049-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 07/26/2021] [Indexed: 06/13/2023]
Abstract
Pot cultivation experiments were conducted to assess the phytoremediation potential of two local agronomic plants, namely Avena sativa and Vicia sativa. Several soils with long-standing contamination and different levels of Polychlorinated biphenyl (PCB) contamination were used for this study. The soil samples came from different regions of Algeria and had different physico-chemical parameters. We studied the influence of these parameters on remediation potential of the two tested plants. The removal rate of the seven PCBs (PCB 28, 52, 101, 138, 153, 156 and 180) was examined after 40 and 90 days. The results showed that the presence of the plants reduced significantly the overall PCB content, ranging initially from 1.33-127.9 mg kg1. After 90 days, the forage plant Vicia sativa allowed us to reach an excess dissipation rate of 56.7% compared to the unplanted control for the most polluted soil. An average dissipation rate of 50% was obtained in the moderately polluted soil. The less contaminated soil had an excess dissipation rate of about 24% for both plants and a predominant dissipation of the low chlorinated PCBs.
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Affiliation(s)
- Ahmed Halfadji
- Department of Sciences and Technology, Faculty of Applied Science, University Ibn-Khaldoun Tiaret, BP 78 P zaâroura 14000, Tiaret, Algeria
- UNIROUEN, Laboratory of Organic and Bioorganic Chemistry, Reactivity and Analysis COBRA UMR CNRS 6014, IUT Evreux, 55 rue St Germain, 27000, Evreux, France
- Laboratory of Organic Analysis Functional (LAOF), Faculty of Chemistry, University of Sciences and Technology Houari Boumediene (USTHB), BP 32 El Alia, 16111, Bab Ezzouar, Algiers, Algeria
| | - Florence Portet-Koltalo
- UNIROUEN, Laboratory of Organic and Bioorganic Chemistry, Reactivity and Analysis COBRA UMR CNRS 6014, IUT Evreux, 55 rue St Germain, 27000, Evreux, France
| | - Abdelkrim Touabet
- Department of Sciences and Technology, Faculty of Applied Science, University Ibn-Khaldoun Tiaret, BP 78 P zaâroura 14000, Tiaret, Algeria
| | - Franck Le Derf
- UNIROUEN, Laboratory of Organic and Bioorganic Chemistry, Reactivity and Analysis COBRA UMR CNRS 6014, IUT Evreux, 55 rue St Germain, 27000, Evreux, France
| | - Christophe Morin
- UNIROUEN, Laboratory of Organic and Bioorganic Chemistry, Reactivity and Analysis COBRA UMR CNRS 6014, IUT Evreux, 55 rue St Germain, 27000, Evreux, France
| | - Nadine Merlet-Machour
- UNIROUEN, Laboratory of Organic and Bioorganic Chemistry, Reactivity and Analysis COBRA UMR CNRS 6014, IUT Evreux, 55 rue St Germain, 27000, Evreux, France.
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Hong S, Khim JS, Naile JE, Park J, Kwon BO, Wang T, Lu Y, Shim WJ, Jones PD, Giesy JP. AhR-mediated potency of sediments and soils in estuarine and coastal areas of the Yellow Sea region: a comparison between Korea and China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2012; 171:216-225. [PMID: 22940735 DOI: 10.1016/j.envpol.2012.08.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 07/13/2012] [Accepted: 08/04/2012] [Indexed: 06/01/2023]
Abstract
Extracts of sediments (n = 45) and soils (n = 37) collected from the coast of the Yellow Sea, in Korea and China, were screened for their ability to induce dioxin-like gene expression in vitro using the H4IIE-luc, transactivation bioassay. Significant dioxin-like potency was observed except for a few soils from Korea. Concentrations of TCDD-EQ (2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents) in sediments were comparable between Korea and China, but concentrations of TCDD-EQ in soil were 2-fold greater from Korea. Mass balance analysis indicated that concentrations of TCDD-EQ were to some degree chemical- and/or matrix-dependent, but were much more site-specific. For example, the proportion of the TCDD-EQ that could be identified varied among locations, which suggests different sources. Unidentified AhR-active compounds represented a greater proportion of the TCDD-EQ in samples from Korea, which suggests that sources in Korea were more complex than those in China. Potential sources of TCDD-EQ were investigated by considering land-uses and local activities.
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Affiliation(s)
- Seongjin Hong
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
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Bedard DL, Bailey JJ, Reiss BL, Jerzak GVS. Development and characterization of stable sediment-free anaerobic bacterial enrichment cultures that dechlorinate aroclor 1260. Appl Environ Microbiol 2006; 72:2460-70. [PMID: 16597944 PMCID: PMC1448987 DOI: 10.1128/aem.72.4.2460-2470.2006] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have developed sediment-free anaerobic enrichment cultures that dechlorinate a broad spectrum of highly chlorinated polychlorinated biphenyls (PCBs). The cultures were developed from Aroclor 1260-contaminated sediment from the Housatonic River in Lenox, MA. Sediment slurries were primed with 2,6-dibromobiphenyl to stimulate Process N dechlorination (primarily meta dechlorination), and sediment was gradually removed by successive transfers (10%) to minimal medium. The cultures grow on pyruvate, butyrate, or acetate plus H(2). Gas chromatography-electron capture detector analysis demonstrated that the cultures extensively dechlorinate 50 to 500 mug/ml of Aroclor 1260 at 22 to 24 degrees C by Dechlorination Process N. Triplicate cultures of the eighth transfer without sediment dechlorinated 76% of the hexa- through nonachlorobiphenyls in Aroclor 1260 (250 mug/ml) to tri- through pentachlorobiphenyls in 110 days. At least 64 PCB congeners, all of which are chlorinated on both rings and 47 of which have six or more chlorines, were substrates for this dechlorination. To characterize the bacterial diversity in the enrichments, we used eubacterial primers to amplify and clone 16S rRNA genes from DNA extracted from cultures grown on acetate plus H(2). Restriction fragment length polymorphism analysis of 107 clones demonstrated the presence of Thauera-like Betaproteobacteria, Geobacter-like Deltaproteobacteria, Pseudomonas species, various Clostridiales, Bacteroidetes, Dehalococcoides of the Chloroflexi group, and unclassified Eubacteria. Our development of highly enriched, robust, stable, sediment-free cultures that extensively dechlorinate a highly chlorinated commercial PCB mixture is a major and unprecedented breakthrough in the field. It will enable intensive study of the organisms and genes responsible for a major PCB dechlorination process that occurs in the environment and could also lead to effective remediation applications.
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MESH Headings
- Aroclors/chemistry
- Aroclors/metabolism
- Bacteria, Anaerobic/classification
- Bacteria, Anaerobic/genetics
- Bacteria, Anaerobic/growth & development
- Bacteria, Anaerobic/metabolism
- Bacteriological Techniques
- Chlorine/metabolism
- Culture Media/chemistry
- DNA, Bacterial/analysis
- DNA, Ribosomal/analysis
- Environmental Pollutants/metabolism
- Genes, rRNA
- Geologic Sediments
- Molecular Sequence Data
- Polychlorinated Biphenyls/metabolism
- Polymorphism, Restriction Fragment Length
- RNA, Ribosomal, 16S/genetics
- Sequence Analysis, DNA
- Soil Pollutants/metabolism
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Affiliation(s)
- Donna L Bedard
- Department of Biology, SC 1W14, Rensselaer Polytechnic Institute, 110 8th St., Troy, NY 12180, USA.
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Schaeffer DJ, Dellinger JA, Needham LL, Hansen LG. Serum PCB profiles in Native Americans from Wisconsin based on region, diet, age, and gender: Implications for epidemiology studies. THE SCIENCE OF THE TOTAL ENVIRONMENT 2006; 357:74-87. [PMID: 15935445 DOI: 10.1016/j.scitotenv.2005.04.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2004] [Accepted: 03/24/2005] [Indexed: 05/02/2023]
Abstract
BACKGROUND Different PCB congeners and different mixtures of congeners have been demonstrated to have different biological actions. More complete characterization of congener profiles in exposure sources may assist in predicting health outcomes. METHODS Thirty-six (36) polychlorinated biphenyl (PCB) congeners were measured by gas chromatography isotope-dilution mass spectrometry (IDMS) in 314 serum samples from Native Americans in Wisconsin, Michigan and Minnesota. Five dietary groups were established based on the quantity and species of fish consumed and the waters from which the fish were caught. Multivariate statistical methods were able to resolve gender and dietary differences in PCB homologue and PCB congener patterns. RESULTS Females had higher proportions of lower chlorinated homologues, including a consistently higher proportion of pentaCB 118. The relative presence of the very labile and volatile PCB 18, above 1% of the total PCB in females from the minimal fish consumption and "other" groups, suggests possible exposure to PCBs in the atmosphere. The dietary group consuming predatory fishes from Lakes Michigan and Superior had the highest serum concentrations of total PCB (mean of 3.1 ng/ml) and the most distinct congener profile. The two dietary groups least dependent on fishing or fishing mostly from inland lakes (non-Great Lakes) had the lowest total PCB concentrations, both with means of 1.4 ng/ml. CONCLUSIONS These serum PCB concentrations were less than those found in earlier studies of fish consumers in the Great Lakes region and may reflect the decrease in PCBs in these lakes.
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Affiliation(s)
- David J Schaeffer
- Department of Veterinary Biosciences, University of Illinois, 2001 South Lincoln Avenue, Urbana, IL 61802, USA.
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Bedard DL, Pohl EA, Bailey JJ, Murphy A. Characterization of the PCB substrate range of microbial dechlorination process LP. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2005; 39:6831-8. [PMID: 16190246 DOI: 10.1021/es050255i] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We have characterized the substrate range of Process LP, a PCB dechlorination activity mediated by anaerobic bacteria, in Housatonic River sediment (Lenox, MA). Process LP has the rare ability to remove unflanked para chlorines from polychlorinated biphenyls (PCBs). We used 2,6-difluoro-4-chlorobiphenyl (DFCB) to activate Process LP in anoxic sediment microcosms and tested its ability to dechlorinate 34 potential PCB substrates, all of which are significant components of PCB mixtures found in contaminated sediments. We used gas chromatography-mass spectrometry to monitor the dechlorination of DFCB and PCBs and the appearance of products. The preferred substrates for Process LP were PCB congeners in which the target para chlorines were flanked by meta chlorines, such as those having 3,4- and 2,4,5-chlorophenyl rings. The unflanked para chlorines on PCBs with 2,4-, 2,4,6-, and sometimes 4-chlorophenyl rings, were also substrates. Furthermore, the data revealed that Process LP can also meta-dechlorinate 2,3-, 2,3,4-, and 2,3,5-chlorophenyl groups on some congeners. A single ortho chlorine on the unattacked ring generally enhanced dechlorination activity, but the presence of 3 or 4 ortho chlorines or a 4-chlorophenyl group decreased the dechlorination efficiency. PCBs with 2,4-, 2,4,6-, 2,3-, and 2,3,5-chlorophenyl rings are often terminal dechlorination products of other microbial dechlorination activities. Since these PCBs are substrates for Process LP, this dechlorination activity works especially well in tandem with other dechlorination activities and further reduces the toxicity and persistence of PCBs. The data presented here will facilitate the construction of accurate models to interpret in situ PCB dechlorination and predict PCB fate.
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Affiliation(s)
- Donna L Bedard
- Department of Biology, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
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Imsilp K, Wiedenmann L, Bordson GO, Morrow CK, Cope R, Hansen LG. Time- and tissue-dependent polychlorinated biphenyl residues in hairless mice after exposure to polychlorinated biphenyl-contaminated soil. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2005; 49:105-18. [PMID: 15981037 DOI: 10.1007/s00244-004-0116-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2004] [Accepted: 11/16/2004] [Indexed: 05/03/2023]
Abstract
Four groups of 16 age-matched female Crl:SKH1-hrBR hairless mice were exposed to either control soil or polychlorinated biphenyl (PCB)-contaminated soil (retrieved from an electrical waste landfill in Southern Illinois) for 11 weeks. The mice were exposed in a study to determine interactions between environmental PCBs and ultraviolet radiation (UVR), but the UVR group did not differ and provided a replicate for the residue study. Ear biopsies were performed immediately after the termination of soil exposure. The mice were maintained in regular bedding for 37 weeks thereafter. The ear-skin, trunk-skin, fat-pad, and liver samples were collected and weighed at the end of the study (week 48) and analyzed for PCB residues. A total of 141 PCB congeners were target analytes. There were significant differences in body weights and food consumption from week 2 to 28. The liver weights of mice treated with PCB only were significantly greater than those of UVR-treated mice. The fat-pad weight did not differ among treated groups. PCB residues in the ear biopsies specimens of mice exposed to contaminated soil were 342.3 and 317.2 ppm in the PCB- and PCB + UVR-treated groups, respectively, and contained both persistent and episodic congeners. After 37 weeks of isolation from soil, the ear PCB residues decreased to 21.5 ppm (PCB group) and 14.5 ppm (PCB + UVR group), and only persistent congeners contributed to the total PCB residues. The accumulation of PCB residues was highest in the fat pad (fat pad > ear skin > trunk skin > liver) in both PCB +/- UVR groups at the end of the study. However, the percentage of individual congeners contributing to total PCBs in these different tissues did not differ.
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Affiliation(s)
- K Imsilp
- Department of Veterinary Biosciences, University of Illinois, 2001 S. Lincoln Ave., Urbana, Illinois 61802, USA
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8
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Pakdeesusuk U, Lee CM, Coates JT, Freedman DL. Assessment of natural attenuation via in situ reductive dechlorination of polychlorinated biphenyls in sediments of the Twelve Mile Creek arm of Lake Hartwell, SC. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2005; 39:945-952. [PMID: 15773465 DOI: 10.1021/es0491228] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Polychlorinated biphenyl (PCB)-contaminated sediment cores taken from five locations in Lake Hartwell, SC, with an increasing distance from the point source were evaluated for the presence of in situ reductive dechlorination of PCBs on the basis of a comparative congener-specific analysis of PCB distribution profiles between historical (1987) and current (1998) sediments from the same sites. A layer of 1998 sediment that was equivalent to 1987 sediment was determined by direct comparison of total PCB depth profiles after correction for any sedimentation that occurred at each location since 1987. Natural capping of contaminated sediments with the continued deposition of new sediments was observed in all locations except the one farthest from the source area. The residual PCB congeners accumulated in the field samples did not vary from site to site. Certain PCB congeners (e.g., 236-24 + 34-34, 245-25, and 23-4 CB) decreased with time and with depth along with an increase in lower chlorinated PCB congeners in all sampling locations. A similarity in distribution profiles between dechlorinated PCBs in laboratory microcosms and in the field samples was observed. These results provide supporting evidence that in situ reductive dechlorination has occurred in the Twelve Mile Creek arm of Lake Hartwell. Several sediment layers, particularlythe sites with highest PCB concentration, showed similar PCB distribution profiles between 1987 and 1998. An additional change in chlorine distribution between 1987 and 1998 at most "equivalent" depths was not observed. The ortho- and para-substituted congeners that accumulated during dechlorination of Aroclor 1254 after nearly 1 yr of incubation in the laboratory were the prominent residual products in all field samples. At a few locations and depths, evidence for dechlorination at surprisingly low concentrations (1-5 ppm) was observed. These results confirm that in situ reductive dechlorination of PCBs is operating at a very slow rate and may have been at a plateau since 1987 for certain depths and certain locations.
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Affiliation(s)
- Usarat Pakdeesusuk
- Department of Environmental Engineering & Science, Clemson University, Clemson, South Carolina 29634-5002, USA
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Ganey PE, Boyd SA. An approach to evaluation of the effect of bioremediation on biological activity of environmental contaminants: dechlorination of polychlorinated biphenyls. ENVIRONMENTAL HEALTH PERSPECTIVES 2005; 113:180-5. [PMID: 15687055 PMCID: PMC1277862 DOI: 10.1289/ehp.6935] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The effectiveness of bioremediation efforts is assessed traditionally from the loss of the chemical of interest. In some cases, analytical techniques are coupled with evaluation of toxicity to organisms representative of those found in the affected environment or surrogate organisms. Little is known, however, about the effect of remediation of environmental chemicals on potential toxicity to mammalian organisms. We discuss both an approach that employs mammalian cell system bioassays and the criteria for selection of the assays. This approach has been used to evaluate the biological response to mixtures of polychlorinated biphenyls (PCBs) before and after remediation by reductive dechlorination. The dechlorination process used results in accumulation of congeners substituted in only the ortho and para positions and containing fewer chlorines than the starting mixtures. Evaluation of the dechlorinated mixture reveals a loss of biological activity that could be ascribed to coplanar PCBs not containing chlorine in the ortho positions. Conversely, biological activity associated with ortho-substituted PCB congeners is unaffected or increased by remediation. Thus, the results of the bioassays are consistent with the remediation-induced change in the profile of PCB congeners and the known mechanisms of action of PCBs. The results emphasize a need for evaluation of the products of remediation for biological activity in mammalian systems. Furthermore, the approach outlined demonstrates the potential to assess the impact of remediation on a range of biological activities in mammalian cells and thus to estimate positive and negative effects of remediation strategies on toxicity. Future needs in this area of research include assays to evaluate biological effects under conditions of exposure that mimic those found in the environment and models to extrapolate effects to assess risk to people and wildlife.
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Affiliation(s)
- Patricia E Ganey
- Department of Pharmacology and Toxicology, Institute of Environmental Toxicology, Michigan State University, East Lansing, Michigan 48824, USA.
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Imsilp K, Hansen L. PCB profiles in mouse skin biopsies and fat from an environmental mixture. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2005; 19:71-84. [PMID: 21783463 DOI: 10.1016/j.etap.2004.04.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2003] [Accepted: 04/29/2004] [Indexed: 05/18/2023]
Abstract
Fat, ear skin and trunk skin were collected from mice exposed to PCB-contaminated soil for PCB specific congener analysis. The soil had been retrieved from a Superfund site prior to remediation. Mice were exposed to either contaminated soil or control soil for 4 weeks. Skin samples were collected immediately after the 4-week exposure and again after 4-week recovery. Out of 141 PCB congeners measured, only 91 peaks representing 103 congeners were above quantification limits. Relative liver weights in PCB-exposed mice doubled indicating significant enzyme induction. Consistent with this observation, total PCB residues declined about 80% during the 4-week recovery. The PCB residue profiles in the ear skin (208mg/kg total) and trunk skin (129mg/kg) after 4-week exposure were identical and similar to those in body fat (370mg/kg) and in the contaminated soil. The results confirmed that both skin tissues are important reservoirs and can serve as useful biopsy media.
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Affiliation(s)
- Kanjana Imsilp
- Department of Veterinary Biosciences, University of Illinois, 2001 S. Lincoln Avenue, Urbana, IL 61802, USA
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Smithwick LA, Quensen JF, Smith A, Kurtz DT, London L, Morris PJ. The inhibition of LPS-induced splenocyte proliferation by ortho-substituted and microbially dechlorinated polychlorinated biphenyls is associated with a decreased expression of cyclin D2. Toxicology 2004; 204:61-74. [PMID: 15369849 DOI: 10.1016/j.tox.2004.06.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 02/12/2004] [Accepted: 06/03/2004] [Indexed: 10/26/2022]
Abstract
Immunological effects of polychlorinated biphenyls (PCBs) have been demonstrated in our laboratories with the peferential inhibition of lipopolysaccharide (LPS)-induced splenocyte proliferation by ortho-substituted PCB congeners. An investigation of the mechanism behind this immunotoxicity revealed an interruption in the progression of murine lymphocytes from G0/G1 into S phase by Aroclor 1242 and the di-ortho-substituted congener, 2,2'-chlorobiphenyl (CB), whereas, a non-ortho-substituted congener, 4,4'-CB, did not affect cell cycle progression. This interruption of cell cycle progression by 2,2'-CB and Aroclor 1242 was associated with a decreased expression of the cell cycle regulatory protein, cyclin D2, while expression was not affected by exposure to the non-ortho-substituted 4,4'-CB. These results suggest the preferential inhibition of LPS-induced splenocyte proliferation by ortho-substituted congeners is a result of a decreased expression of cyclin D2, which leads to an interruption in cell cycle progression. In addition, PCB mixtures with an increased percentage of chlorines in the ortho position following an environmentally occurring degradation process inhibited LPS-induced proliferation, interrupted cell cycle progression, and decreased cyclin D2 expression. This study provides evidence for a mechanism of action of the immunological effects of ortho-substituted individual congeners as well as environmentally relevant mixtures enriched in congeners with this substitution pattern.
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Affiliation(s)
- L Ashley Smithwick
- Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina, Charleston, SC 29412, USA
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12
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Frigo DE, Burow ME, Mitchell KA, Chiang TC, McLachlan JA. DDT and its metabolites alter gene expression in human uterine cell lines through estrogen receptor-independent mechanisms. ENVIRONMENTAL HEALTH PERSPECTIVES 2002; 110:1239-45. [PMID: 12460804 PMCID: PMC1241112 DOI: 10.1289/ehp.021101239] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Endocrine-disrupting organochlorines, such as the pesticide dichlorodiphenyltrichloroethane (DDT), bind to and activate estrogen receptors (ERs), thereby eliciting estrogen-like effects. Although ERs function predominantly through activation of transcription via estrogen-responsive elements, both ERs, alpha and ss, can interact with various transcription factors such as activator protein-1 (AP-1). Additionally, estrogens may regulate early signaling events, suggesting that the biological effects of environmental estrogens may not be mediated through classic ER (alpha and ss) activity alone. We hypothesized that known environmental estrogens, such as DDT and its metabolites, activate AP-1-mediated gene transactivation through both ER-dependent and ER-independent means. Using two Ishikawa human endometrial adenocarcinoma cell line variants that we confirmed to be estrogen responsive [Ishikawa(+)] and estrogen unresponsive [Ishikawa(-)], we generated stably transfected AP-1 luciferase cell lines to identify the role of an estrogen-responsive mechanism in AP-1-mediated gene expression by various stimuli. Our results demonstrate that DDT and dichlorodiphenyldichloroethane (DDD) were the most potent activators of AP-1 activity; 2,2-bis(p-chlorophenyl) acetic acid failed to activate. Although stimulated in both Ishikawa(+) and Ishikawa(-) cells by DDT and its congeners, AP-1 activation was more pronounced in the estrogen-unresponsive Ishikawa(-) cells. In addition, DDT, DDD, and dichlorodiphenyldichloroethylene (DDE) could also stimulate AP-1 activity in the estrogen-unresponsive human embryonic kidney 293 cells using a different promoter context. Thus, our data demonstrate that DDT and its metabolites activate the AP-1 transcription factor independent of ER (alpha or ss) status.
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Affiliation(s)
- Daniel E Frigo
- Molecular and Cellular Biology Program, Tulane University Health Science Center, New Orleans, Louisiana, USA
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Abstract
Under anaerobic conditions, microbial reductive dechlorination of polychlorinated biphenyls (PCBs) occurs in soils and aquatic sediments. In contrast to dechlorination of supplemented single congeners for which frequently ortho dechlorination has been observed, reductive dechlorination mainly attacks meta and/or para chlorines of PCB mixtures in contaminated sediments, although in a few instances ortho dechlorination of PCBs has been observed. Different microorganisms appear to be responsible for different dechlorination activities and the occurrence of various dehalogenation routes. No axenic cultures of an anaerobic microorganism have been obtained so far. Most probable number determinations indicate that the addition of PCB congeners, as potential electron acceptors, stimulates the growth of PCB-dechlorinating microorganisms. A few PCB-dechlorinating enrichment cultures have been obtained and partially characterized. Temperature, pH, availability of naturally occurring or of supplemented carbon sources, and the presence or absence of H(2) or other electron donors and competing electron acceptors influence the dechlorination rate, extent and route of PCB dechlorination. We conclude from the sum of the experimental data that these factors influence apparently the composition of the active microbial community and thus the routes, the rates and the extent of the dehalogenation. The observed effects are due to the specificity of the dehalogenating bacteria which become active as well as changing interactions between the dehalogenating and non-dehalogenating bacteria. Important interactions include the induced changes in the formation and utilization of H(2) by non-dechlorinating and dechlorinating bacteria, competition for substrates and other electron donors and acceptors, and changes in the formation of acidic fermentation products by heterotrophic and autotrophic acidogenic bacteria leading to changes in the pH of the sediments.
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Affiliation(s)
- J Wiegel
- Department of Microbiology and Center for Biological Resource Recovery, University of Georgia, 215 Biological Science Building, Athens, GA, USA
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