Sample records for tetrachlorodibenzodioxin

  1. Matrix effect in determination of 2,3,7,8-tetrachlorodibenzodioxin by mass spectrometry

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    Tondeur, Y.; Albro, P.W.; Hass, J.R.; Harvan, D.J.; Schroeder, J.L.


    Some validation aspects for the determination of part-per-trillion levels of tetrachlorodibenzodioxin in environmental media with gas chromatography/mass spectrometry are examined. A specific matrix effect in the determination system has been noted while using a magnetic sector instrument operating in high resolution selected ion monitoring and low resolution selected reaction monitoring modes. The results emphasize the importance of monitoring simultaneously the response of the ion source with the measured event during the GC/MS experiment. A valid analytical methodology aiming at the accurate quantitative determination of trace quantities of contaminants in complex and partially cleaned-up samples should include such a precautionary measure. 21 references, 3 figures.

  2. Association between Agent Orange exposure and nonmelanotic invasive skin cancer: a pilot study. (United States)

    Clemens, Mark W; Kochuba, Andrew L; Carter, Mary Ella; Han, Kevin; Liu, Jun; Evans, Karen


    Agent Orange, or 2,3,7,8-tetrachlorodibenzodioxin, has been shown to cause indirect DNA damage, producing malignancies. However, its connection to nonmelanotic invasive skin cancer is unclear. This study investigated whether 2,3,7,8-tetrachlorodibenzodioxin exposure increases the incidence of this cancer. The authors retrospectively reviewed the medical records of 100 consecutive male patients with Fitzpatrick skin types I through IV who enrolled in the Agent Orange registry at the Veterans Affairs Hospital of Washington, D.C., between August of 2009 and January of 2010. The study population's mean age was 65.7 years (range, 56 to 80 years). 2,3,7,8-Tetrachlorodibenzodioxin exposure included living or working in contaminated areas (56 percent), actively spraying it (30 percent), or traveling in contaminated areas (14 percent). Fifty-one percent of patients had nonmelanotic invasive skin cancer; 43 percent had chloracne; and 26 percent had other malignancies, such as prostate (14 percent), colon (3 percent), or bladder cancer (2 percent). The nonmelanotic invasive skin cancer incidence rate in the study population (51 percent) was significantly higher than the national age-matched incidence rate (23.8 percent; p < 0.001). High Fitzpatrick skin type score (p = 0.010) and dark eye color (p = 0.036) were associated with a decreased incidence of the cancer. Exposure by means of active spraying (73 percent versus 67 percent; p = 0.003) and presence of chloracne (81 percent versus 28 percent; p < 0.001) were associated with increased nonmelanotic invasive skin cancer incidence rates. 2,3,7,8-Tetrachlorodibenzodioxin exposure appears to be associated with the development of nonmelanotic invasive skin cancer. Further studies are warranted to determine the relative risk within this patient population and to determine appropriate management strategies. Risk, II.

  3. In vitro System for Assessing Dioxin Absorption by Intestinal Epithelial Cells and for Preventing this Absorption by Food Substances


    Natsume, Yayoi; Satsu, Hideo; Hamada, Mika; Kitamura, Kazushige; Okamoto, Naoto; Shimizu, Makoto


    A system for assessing intestinal dioxin absorption was established by applying a Caco-2 cell monolayer and stable dioxin-responsive cell line. The stable dioxin-responsive cell line was established by introducing a plasmid incorporating the human CYP1A1 promoter into human hepatic HepG2 genomic DNA upstream of the luciferase gene. 2,3,7,8-Tetrachlorodibenzodioxin (TCDD) was added to the apical side of differentiated human intestinal epithelial Caco-2 cell monolayers that had been cultured on...

  4. Synthesis of a Molecularly Imprinted Polymer for Dioxin

    Directory of Open Access Journals (Sweden)

    Magda Brattoli


    Full Text Available A molecularly imprinted polymer for recognising selectively 2,3,7,8-tetrachlorodibenzodioxin (TCDD was made by a new non-covalent method employing a“dummy” template. The proposed way represents a simplification of a synthetic schemeproposed by Lübke et al.[1] for covalent imprinting. Comparison of extraction yields of thenovel polymer, a non imprinted polymer and an imprinting polymer, prepared by theoriginal procedure demonstrates the binding capacity of the proposed polymer, which is inprinciple applicable to solid phase extraction (SPE of dioxin.

  5. In vitro System for Assessing Dioxin Absorption by Intestinal Epithelial Cells and for Preventing this Absorption by Food Substances. (United States)

    Natsume, Yayoi; Satsu, Hideo; Hamada, Mika; Kitamura, Kazushige; Okamoto, Naoto; Shimizu, Makoto


    A system for assessing intestinal dioxin absorption was established by applying a Caco-2 cell monolayer and stable dioxin-responsive cell line. The stable dioxin-responsive cell line was established by introducing a plasmid incorporating the human CYP1A1 promoter into human hepatic HepG2 genomic DNA upstream of the luciferase gene. 2,3,7,8-Tetrachlorodibenzodioxin (TCDD) was added to the apical side of differentiated human intestinal epithelial Caco-2 cell monolayers that had been cultured on a semipermeable membrane. The basal medium was taken after an appropriate incubation time and added to the dioxin-responsive cells, the TCDD content then being analyzed by a luciferase assay. The amount of TCDD in the basal medium increased in a dose- and time-dependent manner, the results being sufficiently sensitive and reproducible. The inhibition of TCDD permeability to the Caco-2 cell monolayer by such food substances as chlorophyll, insoluble corn fiber and tea dregs were observed by this in vitro assessment system. The system will therefore be useful to identify food substances having a preventive effect on the intestinal absorption of dioxins.

  6. Organic carbon and chemical contaminant relationships in river and lake sediments

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    Call, D.J.; Markee, T.P. [Univ. of Wisconsin, Superior, WI (United States). Lake Superior Research Inst.; Lodge, K. [Univ. of Minnesota, Duluth, MN (United States). Natural Resources Research Inst.; Cook, P.D.; Ankley, G.T. [Environmental Protection Agency, Duluth, MN (United States). Mid-Continent Ecology Div.


    Sediment collected from 11 sites within the Fox and East Rivers of Brown County, Wisconsin, and two near-shore sites in Green Bay (Lake Michigan) were analyzed for organic carbon content and various pesticides, polychlorinated biphenyls (PCBs), chlorodibenzodioxins, chlorodibenzofurans, polycyclic aromatic hydrocarbons (PAHs), sulfur and heavy metals. Representative chemicals from the organic and inorganic groups were examined for their concentrations at the various sites relative to organic carbon content. Correlations between organic carbon and contaminant concentrations resulted in simple linear regression models with high degrees of predictive capability for most chemicals. For example, chemical concentration relationships with organic carbon (r{sup 2}) were p,p{prime}-DDE (0.85), total PCBs (0.69), 2,3,7,8-tetrachlorodibenzodioxin (0.76), 1,2,3,6,7,8-hexachlorodibenzodioxin (0.87), 2,3,7,8-tetrachlorodibenzofuran (0.71), fluoranthene (0.46), pyrene (0.51), total sulfur (0.75), cadmium (0.76), copper (0.84), lead (0.85), zinc (0.80), chromium (0.04), and nickel (0.39). All correlations were positive with the exception of nickel. This suggests that contaminants within the lower Fox River/Green Bay system are at steady-state with respect to organic carbon. Knowledge of relationships such as this within aquatic systems may be useful in planning and budgeting contaminant mass balance studies within the systems.

  7. A Systems Biology Approach Reveals Converging Molecular Mechanisms that Link Different POPs to Common Metabolic Diseases. (United States)

    Ruiz, Patricia; Perlina, Ally; Mumtaz, Moiz; Fowler, Bruce A


    A number of epidemiological studies have identified statistical associations between persistent organic pollutants (POPs) and metabolic diseases, but testable hypotheses regarding underlying molecular mechanisms to explain these linkages have not been published. We assessed the underlying mechanisms of POPs that have been associated with metabolic diseases; three well-known POPs [2,3,7,8-tetrachlorodibenzodioxin (TCDD), 2,2´,4,4´,5,5´-hexachlorobiphenyl (PCB 153), and 4,4´-dichlorodiphenyldichloroethylene (p,p´-DDE)] were studied. We used advanced database search tools to delineate testable hypotheses and to guide laboratory-based research studies into underlying mechanisms by which this POP mixture could produce or exacerbate metabolic diseases. For our searches, we used proprietary systems biology software (MetaCore™/MetaDrug™) to conduct advanced search queries for the underlying interactions database, followed by directional network construction to identify common mechanisms for these POPs within two or fewer interaction steps downstream of their primary targets. These common downstream pathways belong to various cytokine and chemokine families with experimentally well-documented causal associations with type 2 diabetes. Our systems biology approach allowed identification of converging pathways leading to activation of common downstream targets. To our knowledge, this is the first study to propose an integrated global set of step-by-step molecular mechanisms for a combination of three common POPs using a systems biology approach, which may link POP exposure to diseases. Experimental evaluation of the proposed pathways may lead to development of predictive biomarkers of the effects of POPs, which could translate into disease prevention and effective clinical treatment strategies. Ruiz P, Perlina A, Mumtaz M, Fowler BA. 2016. A systems biology approach reveals converging molecular mechanisms that link different POPs to common metabolic diseases. Environ

  8. Differential sensitivities to dioxin-like compounds PCB 126 and PeCDF between Tg(cyp1a:gfp) transgenic medaka and zebrafish larvae. (United States)

    Xu, Hongyan; Li, Caixia; Suklai, Pacharaporn; Zeng, Qinghua; Chong, Raymond; Gong, Zhiyuan


    It has been intensively documented that there are species-differences in the sensitivity to dioxin-like compounds (DLCs) in mammalian and avian. However, this issue is still unclear in fish. This study aimed at evaluating the differential sensitivities to DLCs in fish larvae. Here, larvae of Tg(cyp1a:gfp) medaka and Tg(cyp1a:gfp) zebrafish were tested with 2,3,7,8-Tetrachlorodibenzodioxin (TCDD), polychlorinated biphenyl 126 (PCB 126) and 2,3,4,7,8,-Pentachlorodibenzofuran (PeCDF). Comparative analyses were performed on induction of GFP fluorescence, expression of endogenous cyp1a mRNAs and EROD activity between the two species after exposure to these chemicals. We found that PCB 126 and PeCDF exposure at high concentrations induced strong GFP expression in multiple organs (liver, head kidney and gut) in both medaka and zebrafish larvae. Moreover, the expression of endogenous cyp1a mRNA was significantly elevated in the zebrafish larvae exposed to TCDD, PCB 126 and PeCDF at different concentrations. Likewise, almost all the exposure conditions could cause prominent elevation of EROD activity in the zebrafish larvae, while the EROD activities were just slightly elevated in the medaka larvae exposed to 1 nM and 0.5 nM of TCDD as well as to 1.5 nM and 15 nM of PeCDF, but not in the medaka larvae exposed to PCB 126. Taken together, zebrafish was proved to be more sensitive than medaka to PCB 126 and to PeCDF in this study. The findings suggested species-specific sensitivity to DLCs in fish and will facilitate choosing a sensitive and reliable fish model or tool to evaluate the risk of dioxins and DLCs exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Autism genes are selectively targeted by environmental pollutants including pesticides, heavy metals, bisphenol A, phthalates and many others in food, cosmetics or household products. (United States)

    Carter, C J; Blizard, R A


    The increasing incidence of autism suggests a major environmental influence. Epidemiology has implicated many candidates and genetics many susceptibility genes. Gene/environment interactions in autism were analysed using 206 autism susceptibility genes (ASG's) from the Autworks database to interrogate ∼1 million chemical/gene interactions in the comparative toxicogenomics database. Any bias towards ASG's was statistically determined for each chemical. Many suspect compounds identified in epidemiology, including tetrachlorodibenzodioxin, pesticides, particulate matter, benzo(a)pyrene, heavy metals, valproate, acetaminophen, SSRI's, cocaine, bisphenol A, phthalates, polyhalogenated biphenyls, flame retardants, diesel constituents, terbutaline and oxytocin, inter alia showed a significant degree of bias towards ASG's, as did relevant endogenous agents (retinoids, sex steroids, thyroxine, melatonin, folate, dopamine, serotonin). Numerous other suspected endocrine disruptors (over 100) selectively targeted ASG's including paraquat, atrazine and other pesticides not yet studied in autism and many compounds used in food, cosmetics or household products, including tretinoin, soy phytoestrogens, aspartame, titanium dioxide and sodium fluoride. Autism polymorphisms influence the sensitivity to some of these chemicals and these same genes play an important role in barrier function and control of respiratory cilia sweeping particulate matter from the airways. Pesticides, heavy metals and pollutants also disrupt barrier and/or ciliary function, which is regulated by sex steroids and by bitter/sweet taste receptors. Further epidemiological studies and neurodevelopmental and behavioural research is warranted to determine the relevance of large number of suspect candidates whose addition to the environment, household, food and cosmetics might be fuelling the autism epidemic in a gene-dependent manner. Copyright © 2016. Published by Elsevier Ltd.

  10. Studies of the combustion of coal/refuse derived fuels using thermogravimetric-Fourier transform infrared-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Huagang; Li, Jigui; Lloyd, W.G.


    According to a report of the Environmental Protection Agency (EPA), `Characterization of Municipal Solid Waste (MSW) in the United States`, the total MSW produced in the U.S. increased from 179 million tons in 1988 to 195 million tons in 1990. The EPA predicted that the country would produce about 216 million tons of garbage in the year 2000. The amount of waste generated and the rapidly declining availability of sanitary landfills has forced most municipalities to evaluate alternative waste management technologies for reducing the volume of waste sent to landfills. The fraction of MSW that is processed by such technologies as separation and recycling, composting, and waste-to-energy was forecast to increase from a few percent today to 30-40% by the year 2000. Waste-to-energy conversion of MSW can appear to be attractive because of the energy recovered, the economic value of recycled materials, and the cost savings derived from reduced landfill usage. However, extra care needs to be taken in burning MSW or refuse-derived fuel (RDF) to optimize the operating conditions of a combustor so that the combustion takes place in an environmentally acceptable manner. For instance, polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) have been found in the precipitator fly ash and flue gas of some incinerator facilities in the United States and Europe. The amount of PCDDs and PCDFs occurs only in the parts-per-billion to parts-per-trillion range, but these chlorinated organics exhibit very high toxicity (LD{sub 50} < 10 {mu}g/Kg). The compound 2,3,7,8-tetrachlorodibenzodioxin has been found to be acnegenic, carcinogenic, and teratogenic. This has slowed or even stopped the construction and operation of waste-to-energy plants.

  11. Toxicogenomic responses in rainbow trout (Oncorhynchus mykiss) hepatocytes exposed to model chemicals and a synthetic mixture

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    Finne, E.F. [Norwegian Institute for Water Research, Gaustadalleen 21, N-0349 Oslo (Norway) and University of Oslo, Department of Biology, P.O. Box 1066, Blindern, N-0316 Oslo (Norway)]. E-mail:; Cooper, G.A. [Centre for Biomedical Research, University of Victoria, BC V8P5C2 (Canada); Koop, B.F. [Centre for Biomedical Research, University of Victoria, BC V8P5C2 (Canada); Hylland, K. [Norwegian Institute for Water Research, Gaustadalleen 21, N-0349 Oslo (Norway); University of Oslo, Department of Biology, P.O. Box 1066, Blindern, N-0316 Oslo (Norway); Tollefsen, K.E. [Norwegian Institute for Water Research, Gaustadalleen 21, N-0349 Oslo (Norway)


    As more salmon gene expression data has become available, the cDNA microarray platform has emerged as an appealing alternative in ecotoxicological screening of single chemicals and environmental samples relevant to the aquatic environment. This study was performed to validate biomarker gene responses of in vitro cultured rainbow trout (Oncorhynchus mykiss) hepatocytes exposed to model chemicals, and to investigate effects of mixture toxicity in a synthetic mixture. Chemicals used for 24 h single chemical- and mixture exposures were 10 nM 17{alpha}-ethinylestradiol (EE2), 0.75 nM 2,3,7,8-tetrachloro-di-benzodioxin (TCDD), 100 {mu}M paraquat (PQ) and 0.75 {mu}M 4-nitroquinoline-1-oxide (NQO). RNA was isolated from exposed cells, DNAse treated and quality controlled before cDNA synthesis, fluorescent labelling and hybridisation to a 16k salmonid microarray. The salmonid 16k cDNA array identified differential gene expression predictive of exposure, which could be verified by quantitative real time PCR. More precisely, the responses of biomarker genes such as cytochrome p4501A and UDP-glucuronosyl transferase to TCDD exposure, glutathione reductase and gammaglutamyl cysteine synthetase to paraquat exposure, as well as vitellogenin and vitelline envelope protein to EE2 exposure validated the use of microarray applied to RNA extracted from in vitro exposed hepatocytes. The mutagenic compound NQO did not result in any change in gene expression. Results from exposure to a synthetic mixture of the same four chemicals, using identical concentrations as for single chemical exposures, revealed combined effects that were not predicted by results for individual chemicals alone. In general, the response of exposure to this mixture led to an average loss of approximately 60% of the transcriptomic signature found for single chemical exposure. The present findings show that microarray analyses may contribute to our mechanistic understanding of single contaminant mode of action as