Craniofacial form is altered by chronic adult exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD in Han/Wistar and Long–Evans rats with different aryl hydrocarbon receptor (AhR structures

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Sabrina B. Sholts

2015-01-01

Full Text Available Mammalian bone has shown a variety of responses to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD exposure in experimental and wildlife studies. Although many responses have been well characterized in the postcranial skeleton, dioxin-induced effects on the cranium are largely unknown. In this study, we investigated the effects of chronic adult exposure to TCDD on cranial size and shape in dioxin-resistant Han/Wistar (H/W and dioxin-sensitive Long–Evans (L–E rat strains. Three-dimensional landmark configurations for the face, vault, and base of the cranium were recorded and analyzed using geometric morphometrics (GM and dose–response modeling. The strongest effects were shown by L–E and H/W rats with daily exposures of 100 and 1000 ng TCDD/kg bw/day, respectively, resulting in significant reductions in centroid size (CS in all three cranial modules for both strains except for the vault in H/W rats. Consistent with previous evidence of intraspecific variation in TCDD resistance, the benchmark doses (CEDs for cranial size reduction in L–E rats were roughly 10-fold lower than those for H/W rats. For both strains, the face showed the greatest size reduction from the highest doses of TCDD (i.e., 3.6 and 6.3% decreases in H/W and L–E rats, respectively, most likely related to dose-dependent reductions in limb bone size and body weight gain. However, intrinsic morphological differences between strains were also observed: although the control groups of H/W and L–E rats had vaults and bases of comparable size, the face was 6.4% larger in L–E rats. Thus, although H/W rats possess an altered aryl hydrocarbon receptor (AhR that appears to mediate and provides some resistance to TCDD exposure, their smaller reductions in facial size may also relate to strain-specific patterns of cranial development and growth. Future research will be aimed at understanding how ontogenetic factors may modulate toxic effects of prenatal and lactational exposure on

Gamma radiation for the decontamination of soil containing dioxin

International Nuclear Information System (INIS)

Chhor, M.P.; Wethington, J.A. Jr.

1986-01-01

Dioxin-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) contamination poses an environmental danger. Different methods for the cleanup of contaminated sites have been proposed. The G value for dioxin dispersed in soil wetted with ethanol is much greater than G values for typical aromatic hydrocarbons. Doses > 6.24 x 10 23 eV/kg lead to decreasing rates of destruction of TCDD, and doses > 24.97 x 10 23 eV/kg are not very effective. Gamma irradiation of contaminated soil apparently will not result in large (powers of 10) decontamination factor. The concept of using gamma radiation for the degradation of TCDD in contaminated soil is about as good or as bad as other methods being tested

Assays of dioxins and dioxin-like compounds in actually contaminated soils using transgenic tobacco plants carrying a recombinant mouse aryl hydrocarbon receptor-mediated β-glucuronidase reporter gene expression system.

Science.gov (United States)

Inui, Hideyuki; Gion, Keiko; Utani, Yasushi; Wakai, Taketo; Kodama, Susumu; Eun, Heesoo; Kim, Yun-Seok; Ohkawa, Hideo

2012-01-01

The transgenic tobacco plant XD4V-26 carrying the recombinant mouse aryl hydrocarbon receptor XD4V-mediated β-glucuronidase (GUS) reporter gene expression system was used for assay of dioxins and dioxin-like compounds consisting of polychlorinated dibenzeno-p-dioxins, polychlorinated dibenzofurans, and coplanar polychlorinated biphenyls (Co-PCBs) in actually contaminated soils. The transgenic tobacco plant XD4V-26 showed a significant dose-dependent induced GUS activity when cultured on MS medium containing PCB126 [toxic equivalency factor (TEF) = 0.1]. In contrast, PCB169 and PCB180, which have 0.03 of TEF and unassigned TEF values, respectively, did not significantly induce GUS activity under the same conditions as with PCB126. When the tobacco plants were cultivated for up to 5 weeks on actually contaminated soils with dioxins and dioxin-like compounds collected from the periphery of an incinerator used for disposal of residential and industrial wastes, GUS activity in the leaves was dose-dependently increased. The plants clearly detected 360 pg-TEQ g(-1) of dioxins and dioxin-like compounds in this assay. There was a positive correlation between GUS activity and TEQ value of dioxins and dioxin-like compounds in the plants. This assay does not require any extraction and purification processes for the actually contaminated soil samples.

The dioxines in environment and health; Les dioxines dans l'environnement et la sante

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-06-15

Dioxines and furans are chlorinated polycyclic aromatic hydrocarbons. Their half life in environment are 10 years. their half life in human organism is 7 years. The techniques to measure and identify these components are complex. Dioxines emissions come from incomplete combustion. 60% of dioxines emissions come from domestic wastes incineration. Soils contamination is made by atmospheric particulates deposit. Dioxines are low soluble in water. The principal mode of exposure for man is the food chain (90 to 95% of global exposure). The effects of dioxines are cancer appearance, increase of congenital malformations, decrease of sex ratio at birth (excess of girls ), decrease of fertility, decrease of birth weight, late on sexual maturity and neurological development. Among other toxic effects are an increase of cardio vascular diseases and increase of lipid rate in blood. (N.C.)

Successive self-propagating sintering process using carbonaceous materials: A novel low-cost remediation approach for dioxin-contaminated solids

Energy Technology Data Exchange (ETDEWEB)

Zhao, Long, E-mail: zhaolong@craes.org.cn [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Dayangfang 8, Beijing 100012 (China); Hou, Hong, E-mail: houhong@craes.org.cn [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Dayangfang 8, Beijing 100012 (China); Zhu, Tengfei; Li, Fasheng [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Dayangfang 8, Beijing 100012 (China); Terada, Akihiko; Hosomi, Masaaki [Department of Chemical Engineering, Faculty of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan)

2015-12-15

Highlights: • A SSPSP using carbonaceous materials for removing dioxin pollutants was developed. • Removal and degradation efficiencies of DL-PCBs were higher than those of PCDD/Fs. • Compositions of PCDD/Fs were dependent on the available precursors in raw materials. • Dechlorination of O{sub 8}CDD and formation pathways of PCDFs were deduced. • Dioxin levels in the effluent gas complied with the International emission limit. - Abstract: The disposal of dioxin-contaminated solids was studied using a novel successive self-propagating sintering process (SSPSP) incorporating a carbonaceous material. Among the five types of carbonaceous materials investigated, Charcoal B displayed optimum adsorbent properties and was selected as the best thermal source in the current remediation approach based on economical efficiency aspects. The feasibility of this proposed approach, removal efficiencies, and congener compositions of dioxins were examined using two types of dioxin-contaminated solids (Fugan sediment and Toyo soil) that displayed different characteristics including the initial concentrations of dioxins. The removal efficiencies of DL-PCBs (“dioxin-like” polychlorinated biphenyls) were higher than those of PCDD/Fs (polychlorinated dibenzo-p-dioxins/dibenzofurans), achieving 99.9 and 92% removal in the Fugan sediment and Toyo soil, respectively. In contrast, the degradation efficiencies of DL-PCBs were lower (i.e., 89.3 and 88.8%, respectively). The initial concentrations of dioxins, available precursors, and properties of the solids strongly influenced the congener compositions and removal efficiencies of dioxins. Furthermore, the dechlorination reaction pathways of high-chlorinated PCDDs and potential regeneration pathways of PCDFs from PCBs were deduced using isotope labeling. The proposed novel low-cost remediation approach for the removal of dioxins from solids is a highly efficient and environmentally sound treatment technology.

Successive self-propagating sintering process using carbonaceous materials: A novel low-cost remediation approach for dioxin-contaminated solids

International Nuclear Information System (INIS)

Zhao, Long; Hou, Hong; Zhu, Tengfei; Li, Fasheng; Terada, Akihiko; Hosomi, Masaaki

2015-01-01

Highlights: • A SSPSP using carbonaceous materials for removing dioxin pollutants was developed. • Removal and degradation efficiencies of DL-PCBs were higher than those of PCDD/Fs. • Compositions of PCDD/Fs were dependent on the available precursors in raw materials. • Dechlorination of O_8CDD and formation pathways of PCDFs were deduced. • Dioxin levels in the effluent gas complied with the International emission limit. - Abstract: The disposal of dioxin-contaminated solids was studied using a novel successive self-propagating sintering process (SSPSP) incorporating a carbonaceous material. Among the five types of carbonaceous materials investigated, Charcoal B displayed optimum adsorbent properties and was selected as the best thermal source in the current remediation approach based on economical efficiency aspects. The feasibility of this proposed approach, removal efficiencies, and congener compositions of dioxins were examined using two types of dioxin-contaminated solids (Fugan sediment and Toyo soil) that displayed different characteristics including the initial concentrations of dioxins. The removal efficiencies of DL-PCBs (“dioxin-like” polychlorinated biphenyls) were higher than those of PCDD/Fs (polychlorinated dibenzo-p-dioxins/dibenzofurans), achieving 99.9 and 92% removal in the Fugan sediment and Toyo soil, respectively. In contrast, the degradation efficiencies of DL-PCBs were lower (i.e., 89.3 and 88.8%, respectively). The initial concentrations of dioxins, available precursors, and properties of the solids strongly influenced the congener compositions and removal efficiencies of dioxins. Furthermore, the dechlorination reaction pathways of high-chlorinated PCDDs and potential regeneration pathways of PCDFs from PCBs were deduced using isotope labeling. The proposed novel low-cost remediation approach for the removal of dioxins from solids is a highly efficient and environmentally sound treatment technology.

Biochemical and cellular mechanisms of low-dose effects

International Nuclear Information System (INIS)

Feinendegen, L.E.; Booz, J.; Muehlensiepen, H.

1988-01-01

The question of health effects from small radiation doses remains open. Individual cells, when being hit by single elemental doses - in low-dose irradiation - react acutely and temporarily by altering control of enzyme activity, as is demonstrated for the case of thymidine kinase. This response is not constant in that it provides a temporary protection of enzyme activity against a second irradiation, by a mechanism likely to be via improved detoxification of intracellular radicals. It must be considered that in the low-dose region radiation may also exert protection against other challenges involving radicals, causing a net beneficial effect by temporarily shielding the hit cell against radicals produced by metabolism. Since molecular alterations leading to late effects are considered a consequence of the initial cellular response, late effects from small radiation doses do not necessarily adhere to a linear dose-effect relationship. The reality of the linear relationship between the risk of late effects from high doses to small doses is an assumption, for setting dose limits, but it must not be taken for predicting health detriment from low doses. (author)

Molecular alterations in childhood thyroid cancer after Chernobyl accident and low-dose radiation risk

International Nuclear Information System (INIS)

Suzuki, Keiji; Mitsutake, Norisato; Yamashita, Shunichi

2012-01-01

The linear no-threshold (LNT) model of radiation carcinogenesis has been used for evaluating the risk from radiation exposure. While the epidemiological studies have supported the LNT model at doses above 100 mGy, more uncertainties are still existed in the LNT model at low doses below 100 mGy. Thus, it is urged to clarify the molecular mechanisms underlying radiation carcinogenesis. After the Chernobyl accident in 1986, significant amount of childhood thyroid cancer has emerged in the children living in the contaminated area. As the incidence of sporadic childhood thyroid cancer is very low, it is quite evident that those cancer cases have been induced by radiation exposure caused mainly by the intake of contaminated foods, such as milk. Because genetic alterations in childhood thyroid cancers have extensively been studied, it should provide a unique chance to understand the molecular mechanisms of radiation carcinogenesis. In a current review, molecular signatures obtained from the molecular studies of childhood thyroid cancer after Chernobyl accident have been overviewed, and new roles of radiation exposure in thyroid carcinogenesis will be discussed. (author)

Dioxin-like activity of brominated dioxins as individual compounds or mixtures in in vitro reporter gene assays with rat and mouse hepatoma cell lines.

Science.gov (United States)

Suzuki, G; Nakamura, M; Michinaka, C; Tue, N M; Handa, H; Takigami, H

2017-10-01

In vitro reporter gene assays detecting dioxin-like compounds have been developed and validated since the middle 1990's, and applied to the determination of dioxin-like activities in various samples for their risk management. Data on characterizing the potency of individual brominated dioxins and their activity in mixture with chlorinated dioxins are still limited on the cell-based assay. This study characterized the dioxin-like activities of the 32 brominated dioxins, such as polybrominated dibenzo-p-dioxins, polybrominated dibenzofurans (PBDFs), coplanar polybrominated biphenyls, mixed halogenated dibenzo-p-dioxins and dibenzofurans (PXDFs), as a sole component or in a mixture by DR-CALUX (dioxin-responsive chemically activated luciferase expression) using the rat hepatoma H4IIE cell line and XDS-CALUX (xenobiotic detection systems-chemically activated luciferase expression) assays using the mouse hepatoma H1L6.1 cell line. The 2,3,7,8-TCDD-relative potencies (REPs) of most of the brominated dioxins were within a factor of 10 of the WHO toxicity equivalency factor (WHO-TEF) for the chlorinated analogues. The REPs of a few PXDFs were an order of magnitude higher than the corresponding WHO-TEFs, indicating their toxicological importance. Results with reconstituted mixtures suggest that the activity of brominated and chlorinated dioxins in both CALUX assays was dose-additive. Thus, obtained results indicated the applicability of the CALUX assays as screening tools of brominated dioxins together with their chlorinated analogues. Copyright © 2017 Elsevier Ltd. All rights reserved.

Concentrations of dioxins and dioxin-like PCBs in feed materials in the Netherlands, 2001-11.

Science.gov (United States)

Adamse, Paulien; Van der Fels-Klerx, H J Ine; Schoss, Stefanie; de Jong, Jacob; Hoogenboom, Ron L A P

2015-01-01

This study aimed to obtain insights into contamination of feed materials used in the Netherlands with dioxins (polychlorinated dibenzo-p-dioxins and dibenzofurans) and dioxin-like polychlorinated biphenyls (PCBs). Monitoring results from the period 2001-11, covering in total 4938 samples, were statistically analysed and evaluated against the statutory limits set at the beginning or during this period. The percentage of samples exceeding maximum levels set within the European Union for either dioxins or the sum of dioxins and dioxin-like PCBs were below 1% for most feed categories, except for fish meal (4.1%), clay minerals (binders and anti-caking agents) (3.4%), and vegetable oils and byproducts (1.7%). For most feed categories, non-compliance with the action threshold (roughly 33% lower than maximum levels) for either dioxins or dioxin-like PCBs was up to three times higher than non-compliance with the respective maximum levels. Exceedance of action thresholds was just above 1% for animal fat, pre-mixtures and feed materials of plant origin excluding vegetable oils. For the categories fish meal, clay minerals, and vegetable oils and byproducts, the action thresholds were exceeded by 5.0%, 9.8% and 3.0% of the samples, respectively. In general, the percentages of samples that exceeded the action thresholds and maximum levels were lower than those reported for the European Union by the European Food Safety Authority (EFSA). In most of the feed materials, there seems to be a decreasing trend in concentrations of dioxins or dioxin-like PCBs over the years. However, a lowering of the limits of quantification during this period and the low concentrations in most samples precludes drawing strong conclusions.

2,3,7,8-Tetrachlorodibenzo-P-Dioxin (TCDD) Dose-Response Studies: Preliminary Literature Search Results and Request for Additional Studies

Science.gov (United States)

EPA invited the public to comment on the preliminary list of in vivo mammalian dose-response citations for 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD). This list was compiled as a first step in the development of EPA’s response to the National Academy of Sciences comments (NAS, 2...

Effect of dioxin on normal and leukemic human hematopoietic cells

Energy Technology Data Exchange (ETDEWEB)

Lambertenghi-Deliliers, G.; Soligo, D. [Univ. degli Studi, Milan (Italy). Dipt. die Ematologia, Ospedale Maggiore Policlinico IRCCS; Fracchiolla, N.S. [Ospedale Maggiore Policlinico IRCCS, Milan (Italy). Dipt. di Ematologia; Servida, F. [Fondazione Matarelli, Milan (Italy); Bertazzi, P.A. [Istituti Clinici di Perfezionamento, Milan (Italy). Dipt. di Medicina del Lavoro

2004-09-15

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) arises from chlorination of phenolic substrates or from partial combustion of organic materials in the presence of chlorine sources. TCDD has a large number of biological effects such as long-lasting skin disease, cardiovascular disease, diabete and cancer. TCDD is the prototypical agonist of the aryl hydrocarbon receptor (AhR), a member of the erb-A family that also includes the receptors for steroids, thyroid hormones, peroxisome proliferators and retinoids. When bound to dioxin, the AhR can bind to DNA and alter the expression of some genes including cytokines and growth factors. In this study, we analyzed the effect of escalating doses of TCDD on human CD34{sup +} progenitor cells from the leukapheresis of normal donors stimulated with G-CSF as well as the human myeloid leukemic cell lines HL60 (promyelocytic leukemia) and K562 (chronic myelogenous leukemia). The possible specific modulation of gene expression induced by the TCDD exposure was then tested by means of microarray analyses.

Liver injury in rhesus monkeys subcutaneously injected with 2.3.7.8-tetrachlorodibenzo-p-dioxin

Energy Technology Data Exchange (ETDEWEB)

Tatsumi, Korenaga; Fukusato, Toshio [Teikyo Univ., Tokyo (Japan). School of Medicine; Kubota, Shunichiro; Ohta, Mari [Tokyo Univ. (Japan); Asaoka, Kazuo [Kyoto Univ., Aichi (Japan); Murata, Nobuo [Teikyo Univ., Kawasaki (Japan). Mizonokuchi Hospital, School of Medicine; Nomizu, Motoyoshi [Hokkaido Univ., Sapporo (Japan); Arima, Akihiro [Shin Nippon Biomedical Laboratories, Ltd., Kagoshima (Japan)

2004-09-15

2.3.7.8-tetrachlorodibenzo-p-dioxin (TCDD) is the most toxic member of dioxins which are environmentally and biologically stable. Exposure to these compounds results in wide variety of effects including immunological dysfunction, tetragenecity and carcinogenesis. The liver is one of the central organs in which TCDD metabolized after absorption into the human and animal bodies. In experiments using rodents, TCDD accumulates and remains stable in the fatty tissues and liver for a long time. Kinetic profile of TCDD in our experiments using rhesus monkeys demonstrated the higher concentrations of TCDD in the fat, liver, and mammary gland. TCDD-induced liver injury in humans has been reported in Japan (PCB), Taiwan (PCB or PCDF), Italy (Sebeso, TCDD), and Vietnam (TCDD). Considerating the pronounced difference between species observed in some studies on non-human primates to assess effects of relatively low dose of TCDD, in the present study, liver injury in rhesus monkeys after a single subcutaneous administration of low dose of TCDD during pregnancy was investigated.

Human papillomavirus E6 and E7 oncoproteins alter cell cycle progression but not radiosensitivity of carcinoma cells treated with low-dose-rate radiation

International Nuclear Information System (INIS)

DeWeese, Theodore L.; Walsh, Jonathan C.; Dillehay, Larry E.; Kessis, Theodore D.; Hedrick, Lora; Cho, Kathleen R.; Nelson, William G.

1997-01-01

Purpose: Low-dose-rate radiation therapy has been widely used in the treatment of urogenital malignancies. When continuously exposed to low-dose-rate ionizing radiation, target cancer cells typically exhibit abnormalities in replicative cell-cycle progression. Cancer cells that arrest in the G2 phase of the cell cycle when irradiated may become exquisitely sensitive to killing by further low-dose-rate radiation treatment. Oncogenic human papillomaviruses (HPVs), which play a major role in the pathogenesis of uterine cervix cancers and other urogenital cancers, encode E6 and E7 transforming proteins known to abrogate a p53-dependent G1 cell-cycle checkpoint activated by conventional acute-dose radiation exposure. This study examined whether expression of HPV E6 and E7 oncoproteins by cancer cells alters the cell-cycle redistribution patterns accompanying low-dose-rate radiation treatment, and whether such alterations in cell-cycle redistribution affect cancer cell killing. Methods and Materials: RKO carcinoma cells, which contain wild-type P53 alleles, and RKO cell sublines genetically engineered to express HPV E6 and E7 oncoproteins, were treated with low-dose-rate (0.25-Gy/h) radiation and then assessed for p53 and p21WAF1/CIP1 polypeptide induction by immunoblot analysis, for cell-cycle redistribution by flow cytometry, and for cytotoxicity by clonogenic survival assay. Results: Low-dose-rate radiation of RKO carcinoma cells triggered p53 polypeptide elevations, p21WAF1/CIP1 induction, and arrest in the G1 and G2 phases of the cell cycle. In contrast, RKO cells expressing E6 and E7 transforming proteins from high-risk oncogenic HPVs (HPV 16) arrested in G2, but failed to arrest in G1, when treated with low-dose-rate ionizing radiation. Abrogation of the G1 cell-cycle checkpoint activated by low-dose-rate radiation exposure appeared to be a characteristic feature of transforming proteins from high-risk oncogenic HPVs: RKO cells expressing E6 from a low

Dioxin formation from waste incineration.

Science.gov (United States)

Shibamoto, Takayuki; Yasuhara, Akio; Katami, Takeo

2007-01-01

samples were burned, were analyzed by gas chromatography/mass spectrometry. Formation of total PCDFs was much higher than that of PCDDs in all samples. The total PCDFs comprised 70%-90% of the total dioxin formed. The amount of total PCDFs formed ranged from 0.78 ng/g (newspaper) to 8,490ng/g (PVC burned in high CO concentration). The amount of total PCDDs formed ranged from 0.02ng/g (newspaper) to 430ng/g (PVC). Coplanar PCBs were found at the lowest level of the dioxins formed. Their formation levels ranged from 0ng/g (newspaper) to 77.6ng/g (PVC). It is obvious that the samples with either inorganic or organic chlorides produced much more dioxins than the sample without chlorides when incinerated under similar conditions. It is not clear how inorganic and organic chloride contribute differently to dioxin formation. Among the metals examined, copper seems to have higher activity toward dioxin formation than other metals. It acted not only as a catalyst but also as a transmitter of heterogeneous chlorine. The toxicity equivalence quantity (TEQ) values generally correlated with the amount of chlorine content in the samples and the amount of dioxin formed in exhaust gases from an incinerator. When the same sample was incinerated at different temperatures, however, the sample burned at low temperature yielded a higher TEQ value than did the sample burned at high temperature. The samples that did not contain chlorine or were not combusted with chlorides exhibited low TEQ values. In contrast, samples with high chlorine content, such as PVC (51.3%), gave high TEQ values. Combustion temperatures may play an important role in dioxin formation in exhaust gases from the incineration of waste materials. However, no significant relationship between dioxin formation and chamber temperatures was reported in the core articles. However, It is obvious that dioxin formation occurred at temperatures above 450'C and was reduced significantly at temperatures above 850 degrees C. The reaction

A dioxin-like compound induces hyperplasia and branching morphogenesis in mouse mammary gland, through alterations in TGF-β1 and aryl hydrocarbon receptor signaling.

Science.gov (United States)

Miret, Noelia; Rico-Leo, Eva; Pontillo, Carolina; Zotta, Elsa; Fernández-Salguero, Pedro; Randi, Andrea

2017-11-01

Hexachlorobenzene (HCB) is a widespread environmental pollutant and a dioxin-like compound that binds weakly to the aryl hydrocarbon receptor (AhR). Because AhR and transforming growth factor β1 (TGF-β1) converge to regulate common signaling pathways, alterations in this crosstalk might contribute to developing preneoplastic lesions. The aim of this study was to evaluate HCB action on TGF-β1 and AhR signaling in mouse mammary gland, through AhR+/+ and AhR-/- models. Results showed a differential effect in mouse mammary epithelial cells (NMuMG), depending on the dose: 0.05μM HCB induced cell migration and TGF-β1 signaling, whereas 5μM HCB reduced cell migration, promoted cell cycle arrest and stimulated the dioxin response element (DRE) -dependent pathway. HCB (5μM) enhanced α-smooth muscle actin expression and decreased TGF-β receptor II mRNA levels in immortalized mouse mammary fibroblasts AhR+/+, resembling the phenotype of transformed cells. Accordingly, their conditioned medium was able to enhance NMuMG cell migration. Assays in C57/Bl6 mice showed HCB (3mg/kg body weight) to enhance ductal hyperplasia, cell proliferation, estrogen receptor α nuclear localization, branch density, and the number of terminal end buds in mammary gland from AhR+/+ mice. Primary culture of mammary epithelial cells from AhR+/+ mice showed reduced AhR mRNA levels after HCB exposure (0.05 and 5μM). Interestingly, AhR-/- mice exhibited an increase in ductal hyperplasia and mammary growth in the absence of HCB treatment, thus revealing the importance of AhR in mammary development. Our findings show that environmental HCB concentrations modulate AhR and TGF-β1 signaling, which could contribute to altered mammary branching morphogenesis, likely leading to preneoplastic lesions and retaining terminal end buds. Copyright © 2017. Published by Elsevier Inc.

Alteration of cytokine profiles in mice exposed to chronic low-dose ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Shin, Suk Chul [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Lee, Kyung-Mi [Global Research Lab, BAERI Institute, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 136-705 (Korea, Republic of); Kang, Yu Mi [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Kim, Kwanghee [Global Research Lab, BAERI Institute, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 136-705 (Korea, Republic of); Kim, Cha Soon; Yang, Kwang Hee; Jin, Young-Woo [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Kim, Chong Soon [Department of Nuclear Medicine, Haeundae Paik Hospital, Inje University, Busan 612-030 (Korea, Republic of); Kim, Hee Sun, E-mail: hskimdvm@khnp.co.kr [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of)

2010-07-09

While a high-dose of ionizing radiation is generally harmful and causes damage to living organisms, a low-dose of radiation has been shown to be beneficial in a variety of animal models. To understand the basis for the effect of low-dose radiation in vivo, we examined the cellular and immunological changes evoked in mice exposed to low-dose radiation at very low (0.7 mGy/h) and low (3.95 mGy/h) dose rate for the total dose of 0.2 and 2 Gy, respectively. Mice exposed to low-dose radiation, either at very low- or low-dose rate, demonstrated normal range of body weight and complete blood counts. Likewise, the number and percentage of peripheral lymphocyte populations, CD4{sup +} T, CD8{sup +} T, B, or NK cells, stayed unchanged following irradiation. Nonetheless, the sera from these mice exhibited elevated levels of IL-3, IL-4, leptin, MCP-1, MCP-5, MIP-1{alpha}, thrombopoietin, and VEGF along with slight reduction of IL-12p70, IL-13, IL-17, and IFN-{gamma}. This pattern of cytokine release suggests the stimulation of innate immunity facilitating myeloid differentiation and activation while suppressing pro-inflammatory responses and promoting differentiation of naive T cells into T-helper 2, not T-helper 1, types. Collectively, our data highlight the subtle changes of cytokine milieu by chronic low-dose {gamma}-radiation, which may be associated with the functional benefits observed in various experimental models.

Dioxins, dioxin-like PCBs and non-dioxin-like PCBs in foodstuffs : occurrence and dietary intake in the Netherlands

NARCIS (Netherlands)

Baars, A.J.; Bakker, M.I.; Baumann, R.A.; Boon, P.E.; Freijer, J.I.; Hoogenboom, L.A.P.; Klaveren, van J.D.; Liem, A.K.D.; Traag, W.A.; Vries, de J.

2004-01-01

Data on occurrence of dioxins (polychlorinated dibenzo-p-dioxins [PCDDs] and dibenzofurans [PCDFs]), dioxin-like PCBs (polychlorinated non-ortho and mono-ortho biphenyls) and non-dioxin-like PCBs (as represented by the so-called indicator-PCBs: congeners 28, 52, 101, 118, 138, 153 and 180) in food

Chemical looping combustion: A new low-dioxin energy conversion technology.

Science.gov (United States)

Hua, Xiuning; Wang, Wei

2015-06-01

Dioxin production is a worldwide concern because of its persistence and carcinogenic, teratogenic, and mutagenic effects. The pyrolysis-chemical looping combustion process of disposing solid waste is an alternative to traditional solid waste incineration developed to reduce the dioxin production. Based on the equilibrium composition of the Deacon reaction, pyrolysis gas oxidized by seven common oxygen carriers, namely, CuO, NiO, CaSO4, CoO, Fe2O3, Mn3O4, and FeTiO3, is studied and compared with the pyrolysis gas directly combusted by air. The result shows that the activity of the Deacon reaction for oxygen carriers is lower than that for air. For four typical oxygen carriers (CuO, NiO, Fe2O3, and FeTiO3), the influences of temperature, pressure, gas composition, and tar on the Deacon reaction are discussed in detail. According to these simulation results, the dioxin production in China, Europe, the United States, and Japan is predicted for solid waste disposal by the pyrolysis-chemical looping combustion process. Thermodynamic analysis results in this paper show that chemical looping combustion can reduce dioxin production in the disposal of solid waste. Copyright © 2015. Published by Elsevier B.V.

Exercise and sport performance with low doses of caffeine.

Science.gov (United States)

Spriet, Lawrence L

2014-11-01

Caffeine is a popular work-enhancing supplement that has been actively researched since the 1970s. The majority of research has examined the effects of moderate to high caffeine doses (5-13 mg/kg body mass) on exercise and sport. These caffeine doses have profound effects on the responses to exercise at the whole-body level and are associated with variable results and some undesirable side effects. Low doses of caffeine (caffeine doses (1) do not alter the peripheral whole-body responses to exercise; (2) improve vigilance, alertness, and mood and cognitive processes during and after exercise; and (3) are associated with few, if any, side effects. Therefore, the ergogenic effect of low caffeine doses appears to result from alterations in the central nervous system. However, several aspects of consuming low doses of caffeine remain unresolved and suffer from a paucity of research, including the potential effects on high-intensity sprint and burst activities. The responses to low doses of caffeine are also variable and athletes need to determine whether the ingestion of ~200 mg of caffeine before and/or during training and competitions is ergogenic on an individual basis.

INFLUENCE OF SHORT-TERM DIETARY MEASURES ON DIOXIN CONCENTRATIONS IN HUMAN-MILK

NARCIS (Netherlands)

PLUIM, HJ; BOERSMA, ER; KRAMER, [No Value; OLIE, K; VANDERSLIKKE, JW; KOPPE, JG

Breast-feeding may expose infants to high levels of toxic chlorinated dioxins. To diminish intake of these lipophilic compounds by the baby, two diets were tested for their ability to reduce concentrations of dioxins in human milk. The diets were a low-fat/high-carbohydrate/low-dioxin diet (about

Gestational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin alters retinoid homeostasis in maternal and perinatal tissues of the Holtzman rat

International Nuclear Information System (INIS)

Kransler, Kevin M.; Tonucci, David A.; McGarrigle, Barbara P.; Napoli, Joseph L.; Olson, James R.

2007-01-01

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), one of the most widely studied environmental contaminants, causes a variety of adverse health effects including teratogenesis and altered development which may be related to disruptions in retinoid homeostasis. The purpose of this study was to determine the effect that gestational administration of TCDD has on retinoid homeostasis in both pregnant Holtzman rats and developing fetuses and neonates. A single oral dose of TCDD (0, 1.5, 3, or 6 μg/kg) was administered to pregnant rats on gestation day 10, with fetuses analyzed on gestation days 17 and 20, and neonates analyzed on post natal day 7. Exposure to TCDD generally produced decreases in the concentrations of retinyl esters, such as retinyl palmitate, and retinol in maternal and perinatal liver and lung, while increasing levels in the maternal kidney. Additionally, perinatal hepatic retinol binding protein 1-dependent retinyl ester hydrolysis was also decrease by TCDD. Sensitivity of the developing perinates to TCDD appeared to have an age-related component demonstrated by an increased rate of mortality and significant alterations to body weight and length on post natal day 7 relative to that observed at gestation day 20. A unique observation made in this study was a significant decrease in lung weight observed in the perinates exposed to TCDD. Taken together, these data demonstrate that TCDD significantly alters retinoid homeostasis in tissues of the developing fetus and neonate, suggesting that their unique sensitivity to TCDD may at least be in part the result of altered retinoid homeostasis

A review of the neurotoxicity of non-dioxin-like polychlorinated biphenyls

Energy Technology Data Exchange (ETDEWEB)

Seegal, R. [Albany Univ., NY (United States). Wadsworth Center, New York State Dept. of Health and School of Public Health

2004-09-15

It is perhaps both presumptuous and somewhat nostalgic for me to present research findings from both myself and others describing the changes in central nervous system (CNS) function that occur following exposure to non-dioxin-like polychlorinated biphenyls (PCBs) at the 2004 Dioxin meeting. Presumptuous because my presentation occurs during this meeting where the majority of the research is concerned with the consequences of exposure to dioxins (the most toxic substance produced by man) and nostalgic because, in 1992, I presented some of my earliest work demonstrating that non-dioxin-like PCBs were capable of significantly altering neurochemical function. Much has changed in the intervening twelve years. Laboratories in the United States and Europe now routinely study and describe the neurotoxicological effects of developmental and in vitro exposure to non-dioxin-like PCBs. My task will be to briefly describe the highlights of that research and suggest additional approaches that will hopefully increase our ability to understand the mechanisms of action of non-dioxin-like PCBs on neuronal and behavioral function in populations of exposed humans.

Anaerobic reductive dehalogenation of polychlorinated dioxins

Energy Technology Data Exchange (ETDEWEB)

Bunge, Michael [Aarhus Univ. (DK). Dept. of Biological Sciences, Microbiology, and Interdisciplinary Nanoscience Centre (iNANO); Lechner, Ute [Halle-Wittenberg Univ., Halle (Germany). Inst. of Biology/Microbiology

2009-09-15

Polychlorinated dibenzo-p-dioxins and -furans (PCDD/Fs) are among the most harmful environmental contaminants. Their widespread distribution due to unintentional or unknown release coincides with environmental persistence, acute and chronic toxicity to living organisms, and long-term effects due to the compounds' tendency for bioaccumulation and biomagnification. While microbial aerobic degradation of PCDD/Fs is mainly reported for the turnover of low chlorinated congeners, this review focuses on anaerobic reductive dehalogenation, which may constitute a potential remediation strategy for polychlorinated compounds in soils and sediments. Microorganisms in sediments and in microcosms or enrichment cultures have been shown to be involved in the reductive dechlorination of dioxins. Bacteria related to the genus Dehalococcoides are capable of the reductive transformation of dioxins leading to lower chlorinated dioxins including di- and monochlorinated congeners. Thus, reductive dehalogenation might be one of the very few mechanisms able to mediate the turnover of polychlorinated dioxins by reducing their toxicity and paving the way for a subsequent breakdown of the carbon skeleton. (orig.)

Mode of action of dioxin-like versus non-dioxin-like PCBs

Energy Technology Data Exchange (ETDEWEB)

Schoeters, G. [VITO (Flemish Institute for Technological Research), Dept. of Environemental Toxicology (Belgium)]|[Antwerp Univ. (Belgium); Birnbaum, L. [United States Environmental Protection Agency, Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory (United States)

2004-09-15

Exposure of humans to polychlorinated biphenyls has been associated with different adverse effects such as immune impairment, changes in hormone levels, reproductive and neuropsychological changes and cancer. It is difficult to attribute the observed effects to either dioxin-like, non-dioxin-like PCBs or to both. All known human exposures are mixed, comprising dioxin and non-dioxin like PCB congeners as well as dioxins and furans. The purpose of this work was to evaluate, based on mechanistic data available in the open literature, whether non-dioxin like PCBs (NDL-PCBs) themselves may pose specific health risks. It is clear that dioxin and NDL-PCBs differ in the spectrum of metabolizing enzymes they induce, but the mechanistic links to health of these biochemical changes remain unclear at the moment. NDL-PCBs also cause immunotoxicity and tumor promotion via different mechanisms than do dioxin-like PCBs. We focus on neurotoxicity which has been associated with developmental exposure to PCBs and which is considered as one of the most sensitive adverse health effects.

Estimated dietary dioxin exposure and breast cancer risk among women from the French E3N prospective cohort.

Science.gov (United States)

Danjou, Aurélie M N; Fervers, Béatrice; Boutron-Ruault, Marie-Christine; Philip, Thierry; Clavel-Chapelon, Françoise; Dossus, Laure

2015-03-17

Dioxins are environmental and persistent pollutants mostly emitted from combustion facilities (e.g. waste incinerators, metal and cement industries). Known to be endocrine disrupting chemicals, dioxins are suspected to increase breast cancer (BC) risk. Although diet is considered the primary source of dioxin exposure, no previous study has been published on dietary dioxin exposure in relation to BC risk. We aimed to assess dietary dioxin exposure among women from the E3N cohort and estimate BC risk associated with this exposure. The study included 63,830 women from the E3N cohort who completed a diet history questionnaire (DHQ) in 1993 and were followed until 2008. Dietary dioxin exposure was estimated by combining consumption data from the E3N DHQ and food dioxin contamination data from a French national monitoring program. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated by Cox models adjusted for BC risk factors. Mean dietary dioxin exposure was estimated at 1.3 ± 0.4 pg/kg body weight (BW)/day. A 0.4 pg/kg BW/d increase in dioxin intake was not associated with overall BC risk (HR = 1.00; 95% CI: 0.96, 1.05). A significant decrease in risk of estrogen receptor negative (ER-)/progesterone receptor negative (PR-) tumors was observed among post-menopausal women in the upper quartile of estimated dioxin intake (HR for Q4 vs. Q1: 0.65; 95% CI: 0.45, 0.96; P for trend across quartiles = 0.0463). Overall, no association between estimated dietary dioxin exposure and BC risk was found among E3N women. Further studies should include both dietary and environmental exposures to determine whether low-dose dioxin exposure is associated with BC risk.

Soil dioxin concentrations in Baden-Wuerttemberg

International Nuclear Information System (INIS)

Wolf, D.

1993-01-01

Soil dioxin levels in Baden-Wuerttemberg are generally low. Where high dioxin concentrations have been reported like in Rastatt, Rheinfelden, Crailsheim-Maulach and Eppingen these phenomena are local. Already at less than 100 metres distance, drastically lower concentrations are measured. At 1500 to 2000 metres distance the values are back to the ordinary background level. A programme for detecting sources of emission in the entire state revealed no further sites of heavy contamination. For this assessment of soil dioxin concentrations in Baden-Wuerttemberg 1275 soil samples were used, which is a vast amount also in comparison with nation-wide surveys. The average dioxin content in farmland is about 1 ng I-TEq/kg m T . Soil dioxin concentrations are the higher the greater the density of settlements and industry. In cities they are about three to five times higher than the ubiquitous background concentration. The highest concentrations measured were 5-20 ng I-TE/kg in garden soils in cities. Sewage sludge may be a significant source of dioxin contamination for farmland, far beyond the ubiquitous background concentration. Automobile exhaust gas caused higher soil contamination within 10 m along both sides of the roads as a function of traffic. Because scavengers in gasoline are now prohibited and catalysts are becoming more and more common the rate of additional dioxin and furan contamination due to traffic will decrease. Currently, traffic-related emissions in Baden-Wuerttemberg are well below 2 g I-TEq. (orig./EF) [de

Application of accelerated evaluation method of alteration temperature and constant dose rate irradiation on bipolar linear regulator LM317

International Nuclear Information System (INIS)

Deng Wei; Wu Xue; Wang Xin; Zhang Jinxin; Zhang Xiaofu; Zheng Qiwen; Ma Wuying; Lu Wu; Guo Qi; He Chengfa

2014-01-01

With different irradiation methods including high dose rate irradiation, low dose rate irradiation, alteration temperature and constant dose rate irradiation, and US military standard constant high temperature and constant dose rate irradiation, the ionizing radiation responses of bipolar linear regulator LM317 from three different companies were investigated under the operating and zero biases. The results show that compared with constant high temperature and constant dose rate irradiation method, the alteration temperature and constant dose rate irradiation method can not only very rapidly and accurately evaluate the dose rate effect of three bipolar linear regulators, but also well simulate the damage of low dose rate irradiation. Experiment results make the alteration temperature and constant dose rate irradiation method successfully apply to bipolar linear regulator. (authors)

Levels of dioxins and dioxin-like PCBs in food and feed in Europe

Energy Technology Data Exchange (ETDEWEB)

Gallani, B.; Verstraete, F. [European Commission, DG SANCO, Brussels (Belgium); Boix, A.; Holst, C. von; Anklam, E. [European Commission, Joint Research Centre, Geel (Belgium)

2004-09-15

Regulation (EC) No 466/2001 as amended by Council Regulation (EC) No 2375/2001 of November 2001 setting maximum levels for certain contaminants in foodstuffs, inter alia dioxins, stipulates that foodstuffs should not, when placed on the market, contain higher contaminant levels than those specified in that Regulation. The Regulation also states that the Commission shall review Section 5 of Annex I, which outlines the maximum levels for dioxins and furans in food, by 31 December 2004 at the latest, in the light of new data on the presence of dioxins and dioxin-like PCBs, in particular with a view to the inclusion of dioxin-like PCBs in the levels to be set. Section 5 of Annex I shall be further reviewed by 31 December 2006 at the latest with the aim of significantly reducing the maximum levels. An EC Recommended Monitoring Programme for Food (Ref 1) was discussed to provide the Commission with the necessary data to make it possible to meet these commitments. A considerable amount of data was received by the Commission on the occurrence of dioxins and dioxin-like PCBs in food and was analysed to determine whether any patterns emerge in the ratios between dioxins and dioxin-like PCBs in certain food types or in certain areas. Directive 2002/32/EC of the European Parliament and of the Council as amended by Commission Directive 2003/57/EC of 17 June 2003 on undesirable substances in animal feed establishes maximum levels for dioxins in several feed materials and compound feeding stuffs. Similar revision clauses to the Regulation on food apply to this Directive on feeding stuffs. A monitoring programme similar to the one recommended for food was discussed for undesirable substances in animal feed (Ref 2). Data submitted by Member states on the occurrence of dioxins and dioxin-like PCBs in feed have also been analysed to determine whether any patterns emerge in the ratios between dioxins and dioxin-like PCBs in certain feedstuffs or in certain areas. This paper describes

Dioxin and Dioxin-Like Compounds Toxic Equivalency Information

Science.gov (United States)

EPA requires that, in addition to the total grams released for the entire dioxin and dioxin-like compounds category, TRI facilities must report the quantity for each individual member on a new Form R Schedule 1.

A margin-of-exposure approach to assessment of noncancer risks of dioxins based on human exposure and response data.

Science.gov (United States)

Aylward, Lesa L; Goodman, Julie E; Charnley, Gail; Rhomberg, Lorenz R

2008-10-01

Risk assessment of human environmental exposure to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDFs) and other dioxin-like compounds is complicated by several factors, including limitations in measuring intakes because of the low concentrations of these compounds in foods and the environment and interspecies differences in pharmacokinetics and responses. We examined the feasibility of relying directly on human studies of exposure and potential responses to PCDD/PCDFs and related compounds in terms of measured lipid-adjusted concentrations to assess margin of exposure (MOE) in a quantitative, benchmark dose (BMD)-based framework using representative exposure and selected response data sets. We characterize estimated central tendency and upper-bound general U.S. population lipid-adjusted concentrations of PCDD/PCDFs from the 1970s and early 2000s based on available data sets. Estimates of benchmark concentrations for three example responses of interest (induction of cytochrome P4501A2 activity, dental anomalies, and neonatal thyroid hormone alterations) were derived based on selected human studies. The exposure data sets indicate that current serum lipid concentrations in young adults are approximately 6- to 7-fold lower than 1970s-era concentrations. Estimated MOEs for each end point based on current serum lipid concentrations range from 100 for dental anomalies-approximately 6-fold greater than would have existed during the 1970s. Human studies of dioxin exposure and outcomes can be used in a BMD framework for quantitative assessments of MOE. Incomplete exposure characterization can complicate the use of such studies in a BMD framework.

Size fractionation of waste-to-energy boiler ash enables separation of a coarse fraction with low dioxin concentrations

DEFF Research Database (Denmark)

Weidemann, E.; Allegrini, Elisa; Astrup, Thomas Fruergaard

2016-01-01

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) formed in modern Waste-to-Energy plants are primarily found in the generated ashes and air pollution control residues, which are usually disposed of as hazardous waste. The objective of this study was to explore the occurrence of PCDD....../F in different grain size fractions in the boiler ash, i.e. ash originating from the convection pass of the boiler. If a correlation between particle size and dioxin concentrations could be found, size fractionation of the ashes could reduce the total amount of hazardous waste. Boiler ash samples from ten...... sections of a boiler's convective part were collected over three sampling days, sieved into three different size fractions - 0.355. mm - and analysed for PCDD/F. The coarse fraction (>0.355. mm) in the first sections of the horizontal convection pass appeared to be of low toxicity with respect to dioxin...

Dioxin exposure in breast milk and infant neurodevelopment in Vietnam.

Science.gov (United States)

Tai, Pham The; Nishijo, Muneko; Anh, Nguyen Thi Nguyet; Maruzeni, Shoko; Nakagawa, Hideaki; Van Luong, Hoang; Anh, Tran Hai; Honda, Ryumon; Kido, Teruhiko; Nishijo, Hisao

2013-09-01

Dioxin levels in the breast milk of mothers residing near hot spots of dioxin contamination areas in South Vietnam remain much higher than in unsprayed areas, suggesting that fetuses and breast-fed infants may be exposed to high levels of dioxins. The present study investigated the association of infant neurodevelopment in early infancy and dioxin exposure during the perinatal period. The study involved 216 mother-infant pairs living near the Da Nang airbase, a dioxin contaminated area in Vietnam. Mothers and infants were followed from birth until infants were 4 months old. Dioxin levels in breast milk were measured to estimate the perinatal dioxin exposure, including the infant daily dioxin intake (DDI) via breastfeeding. Infant neurodevelopmental parameters, including cognitive, language and motor domains were assessed at approximately 4 months using the Bayley Scales of Infant and Toddler Development, third edition (Bayley-III). The level of 2,3,7,8-tetrachlorodibenzo-p-dioxin and polychlorinated dibenzo-p-dioxins/furans-toxic equivalents in breast milk and the infant DDI showed significant inverse correlations with neurodevelopmental scores. When the subjects were divided into four groups according to dioxin levels in breast milk, the moderate and high DDI groups had significantly lower cognitive, composite motor and fine motor scores, and the high polychlorinated dibenzo-p-dioxins/furans-toxic equivalents group had significantly lower fine motor score than the low exposure group. For all domains, neurodevelopmental scores were decreased with increase in the level of 2,3,7,8-tetrachlorodibenzo-p-dioxin. The present study demonstrates a considerable impact of perinatal dioxin exposure on neurodevelopment in 4-month-old infants living in contaminated areas in Vietnam.

Reproduction of European eel jeopardised by high levels of dioxins and dioxin-like PCBs?

Science.gov (United States)

Geeraerts, C; Focant, J-F; Eppe, G; De Pauw, E; Belpaire, C

2011-09-01

Dioxins, furans and dioxin-like polychlorinated biphenyls (PCBs) were analysed in muscle tissue from yellow phased European eel (Anguilla anguilla) from 38 sites in Belgium. Dioxin concentrations in eel vary considerably between sampling locations, indicating that yellow eel is a good indicator of local pollution levels. Measured levels of dioxin-like PCBs are much higher than those of the dioxins and furans. In the majority of the sites, eel has levels considered to be detrimental for their reproduction. Field levels of dioxin and dioxin-like PCBs are therefore suggested as an additional causal factor contributing to the decline of the European eel. 42% of the sampling sites show especially dioxin-like PCB levels exceeding the European consumption level (with a factor 3 on average). Human consumption of eel, especially in these highly contaminated sites, seems unjustified. Copyright © 2011 Elsevier B.V. All rights reserved.

The proficiency testing of determination of dioxins in food

Energy Technology Data Exchange (ETDEWEB)

Matsuda, R.; Tsutsumi, T.; Maitani, T. [National Institute of Health Sciences, Tokyo (Japan); Toyoda, M. [Jissen Womens Univ., Hino (Japan)

2004-09-15

Food intake is the main route of human dioxin exposure, making the determination of dioxins in food indispensable for risk assessment and risk management of dioxins. The uncertainty of analytical results, however, can be very great because of the low concentration of the analytes and complicated cleanup procedures. The risk assessment of dioxins based on analytical results also suffers from a similar degree of uncertainty. The Ministry of Health, Labor and Welfare of Japan has published ''Guideline for the Determination of Dioxins in Food'' to standardize the analytical procedures. The guideline contains the quality assurance procedures to obtain reliable analytical results and recommends participation in the relevant proficiency testing scheme. The proficiency testing provides the fair evaluation of the analytical results. The central science laboratory in England and the food and drug safety center in Japan offer the proficiency testing on food. The National Institute of Health Sciences of Japan (NIHS) also has carried out proficiency testing of dioxins in food since 1998 to assure the quality of analytical results for dioxins. In this presentation we will show the results of 5 rounds of proficiency testing.

Dioxin emissions and sources

International Nuclear Information System (INIS)

1994-01-01

The papers presented at the seminar discussed dioxin emissions and sources, dioxin pollution of soils, waste water and sewage sludge, stocktaking of emission sources, and exposure and risk analyses for dioxin and other pollutants. (EF) [de

Estimated cancer risk of dioxins to humans using a bioassay and physiologically based pharmacokinetic model

International Nuclear Information System (INIS)

Maruyama, Wakae; Aoki, Yasunobu

2006-01-01

The health risk of dioxins and dioxin-like compounds to humans was analyzed quantitatively using experimental data and mathematical models. To quantify the toxicity of a mixture of three dioxin congeners, we calculated the new relative potencies (REPs) for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD), and 2,3,4,7,8- pentachlorodibenzofuran (PeCDF), focusing on their tumor promotion activity. We applied a liver foci formation assay to female SD rats after repeated oral administration of dioxins. The REP of dioxin for a rat was determined using dioxin concentration and the number of the foci in rat liver. A physiologically based pharmacokinetic model (PBPK model) was used for interspecies extrapolation targeting on dioxin concentration in liver. Toxic dose for human was determined by back-estimation with a human PBPK model, assuming that the same concentration in the target tissue may cause the same level of effect in rats and humans, and the REP for human was determined by the toxic dose obtained. The calculated REPs for TCDD, PeCDD, and PeCDF were 1.0, 0.34, and 0.05 for rats, respectively, and the REPs for humans were almost the same as those for rats. These values were different from the toxic equivalency factors (TEFs) presented previously (Van den Berg, M., Birnbaum, L., Bosveld, A.T.C., Brunstrom, B., Cook, P., Feeley, M., Giesy, J.P., Hanberg, A., Hasegawa, R., Kennedy, S.W., Kubiak, T., Larsen, J.C., Rolaf van Leeuwen, F.X., Liem, A.K.D., Nolt, C., Peterson, R.E., Poellinger. L., Safe, S., Schrenk, D., Tillitt, D, Tysklind, M., Younes, M., Waern, F., Zacharewski, T., 1998. Toxic equivalency factors (TEFs) for PCBs, PCDDs, PCDFs for humans and wildlife. Environ. Health Perspect. 106, 775-792). The relative risk of excess liver cancer for Japanese people in general was 1.7-6.5 x 10 -7 by TCDD only, and 2.9-11 x 10 -7 by the three dioxins at the present level of contamination

Optøjer og dioxiner

DEFF Research Database (Denmark)

Berg, Rolf W.

2008-01-01

brintatomer er udskiftet med chlor (såkaldt chlor-substitueret dioxin), man tænker på, når man snakker om dioxin (se boks). Dioxiner er ekstremt giftige stoffer. Indtagelse of nogle få milligram regnes for dødelig for en voksen person. Det er dog ikke realistisk at blive udsat for så meget dioxin, og der...... findes ingen kendte dødsfald på grund of akut dioxinforgiftning. Til gengæld kan dioxin påvirke et bestemt proteinsystem ved navn aryl hydrocarbon receptor (AhR), give fosterskader og sandsynligvis fremkalde kræftsygdomme. Dioxin og brande. Dioxiner dannes let som reaktionsprodukter ved kemiske...... flammerne til røgen, mens resten blev tilbage i asken. Røgen spredes over store områder, og dioxinen falder ned lidt overalt. Forholdene betyder meget for dioxindannelsen, idet dårlig og ustabil forbrænding ved lave temperaturer (som det ofte er tilfældet ved brande) vil give relativt mere dioxin. Desuden...

Formation of dioxins and furans during combustion of treated wood

Energy Technology Data Exchange (ETDEWEB)

Tame, Nigel W.; Dlugogorski, Bogdan Z.; Kennedy, Eric M. [Process Safety and Environment Protection Research Group, School of Engineering, The University of Newcastle, Callaghan, NSW 2308 (Australia)

2007-08-15

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F, dioxin) are produced in combustion of wood treated with copper-based preservatives. This review summarises and analyses the pertinent literature on the role of preservatives in the formation of dioxin in the low-temperature, vitiated environment that exists in the domestic combustion of wood, and in large-scale fires. Until recently, the role of preservatives was not thoroughly examined in the literature with respect to fires, as incineration attracted most of the research focus. However, latest studies have demonstrated that some current and emerging wood preservatives significantly increase dioxin formation during combustion in domestic stoves and in fires. The following pathways are identified: (i) copper, a common biocide that is chemically bound to the wood, is an important dioxin catalyst, (ii) preservative metals promote smouldering of wood char following cessation of flaming, providing the required temperature environment for dioxin formation, and (iii) chlorinated organics added as secondary preservative components yield dioxin precursors upon thermal decomposition. These conclusions indicate that it remains hazardous to dispose of preservative impregnated timber via domestic combustion even if arsenic is not present. (author)

Environmental health risk assessment of dioxin in foods at the two most severe dioxin hot spots in Vietnam.

Science.gov (United States)

Tuyet-Hanh, Tran Thi; Minh, Nguyen Hung; Vu-Anh, Le; Dunne, Michael; Toms, Leisa-Maree; Tenkate, Thomas; Thi, Minh-Hue Nguyen; Harden, Fiona

2015-07-01

Bien Hoa and Da Nang airbases were bulk storages for Agent Orange during the Vietnam War and currently are the two most severe dioxin hot spots. This study assesses the health risk of exposure to dioxin through foods for local residents living in seven wards surrounding these airbases. This study follows the Australian Environmental Health Risk Assessment Framework to assess the health risk of exposure to dioxin in foods. Forty-six pooled samples of commonly consumed local foods were collected and analyzed for dioxin/furans. A food frequency and Knowledge-Attitude-Practice survey was also undertaken at 1000 local households, various stakeholders were involved and related publications were reviewed. Total dioxin/furan concentrations in samples of local "high-risk" foods (e.g. free range chicken meat and eggs, ducks, freshwater fish, snail and beef) ranged from 3.8 pg TEQ/g to 95 pg TEQ/g, while in "low-risk" foods (e.g. caged chicken meat and eggs, seafoods, pork, leafy vegetables, fruits, and rice) concentrations ranged from 0.03 pg TEQ/g to 6.1 pg TEQ/g. Estimated daily intake of dioxin if people who did not consume local high risk foods ranged from 3.2 pg TEQ/kg bw/day to 6.2 pg TEQ/kg bw/day (Bien Hoa) and from 1.2 pg TEQ/kg bw/day to 4.3 pg TEQ/kg bw/day (Da Nang). Consumption of local high risk foods resulted in extremely high dioxin daily intakes (60.4-102.8 pg TEQ/kg bw/day in Bien Hoa; 27.0-148.0 pg TEQ/kg bw/day in Da Nang). Consumption of local "high-risk" foods increases dioxin daily intakes far above the WHO recommended TDI (1-4 pg TEQ/kg bw/day). Practicing appropriate preventive measures is necessary to significantly reduce exposure and health risk. Copyright © 2015 Elsevier GmbH. All rights reserved.

Bioaccumulation and trophic transfer of dioxins in marine copepods and fish

International Nuclear Information System (INIS)

Zhang Qiong; Yang Liuyan; Wang Wenxiong

2011-01-01

Despite the great concerns about dioxins in the marine environments, the biokinetics and bioaccumulation of these compounds in marine organisms remains little known. Using radioactive tracers the aqueous uptake, dietary assimilation efficiency, and elimination of dioxins were measured in marine phytoplankton, copepods and seabream. The calculated uptake rate constant of dioxins decreased with increasing trophic levels, whereas the dietary assimilation efficiency (AE) was 28.5-57.6% in the copepods and 36.6-70.2% in the fish. The dietary AE was highly dependent on the food concentrations and food type. The elimination rate constant of dioxin in the copepods varied with different exposure pathways as well as food concentration and food type. Biokinetic calculation showed that dietary accumulation was the predominant pathway for dioxin accumulation in marine copepods and fish. Aqueous uptake can be an important pathway only when the bioconcentration of dioxins in the phytoplankton was low. - Highlights: → Radiotracer was used to quantify the biokinetics of dioxins in a marine food chain. → Aqueous uptake rate of dioxins decreased with increasing trophic levels. → Dietary assimilation efficiencies were comparable between the copepods and the fish. → Both food type and density significantly affected the dietary assimilation of dioxins. → Diet was the predominant pathway for dioxin accumulation in marine copepods and fish. - Biokinetic calculation showed that dietary accumulation was the predominant pathway for dioxin accumulation in marine copepods and fish.

Dioxin-induced acute cardiac mitochondrial oxidative damage and increased activity of ATP-sensitive potassium channels in Wistar rats

International Nuclear Information System (INIS)

Pereira, Susana P.; Pereira, Gonçalo C.; Pereira, Cláudia V.; Carvalho, Filipa S.; Cordeiro, Marília H.; Mota, Paula C.; Ramalho-Santos, João; Moreno, António J.; Oliveira, Paulo J.

2013-01-01

The environmental dioxin 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is classified as a Group 1 human carcinogen and teratogenic agent. We hypothesize that TCDD-induced oxidative stress may also interfere with mitochondrial ATP-sensitive potassium channels (mitoKATP), which are known to regulate and to be regulated by mitochondrial redox state. We investigated the effects of an acute treatment of male Wistar rats with TCDD (50 μg/kg i.p.) and measured the regulation of cardiac mitoKATP. While the function of cardiac mitochondria was slightly depressed, mitoKATP activity was 52% higher in animals treated with TCDD. The same effects were not observed in liver mitochondria isolated from the same animals. Our data also shows that regulation of mitochondrial ROS production by mitoKATP activity is different in both groups. To our knowledge, this is the first report to show that TCDD increases mitoKATP activity in the heart, which may counteract the increased oxidative stress caused by the dioxin during acute exposure. -- Highlights: •Acute TCDD treatment of Wistar rats causes cardiac oxidative stress. •Acute TCDD treatment causes cardiac mitochondrial alterations. •Mitochondrial liver vs. heart alterations are distinct. •TCDD treatment resulted in altered activity of cardiac mitochondrial K-ATP channels. -- Dioxin alters the regulation of cardiac mitochondrial ATP-sensitive potassium channels and disturbs mitochondrial physiology

Effects of Chronic Low-Dose Radiation on Human Neural Progenitor Cells

Science.gov (United States)

Katsura, Mari; Cyou-Nakamine, Hiromasa; Zen, Qin; Zen, Yang; Nansai, Hiroko; Amagasa, Shota; Kanki, Yasuharu; Inoue, Tsuyoshi; Kaneki, Kiyomi; Taguchi, Akashi; Kobayashi, Mika; Kaji, Toshiyuki; Kodama, Tatsuhiko; Miyagawa, Kiyoshi; Wada, Youichiro; Akimitsu, Nobuyoshi; Sone, Hideko

2016-01-01

The effects of chronic low-dose radiation on human health have not been well established. Recent studies have revealed that neural progenitor cells are present not only in the fetal brain but also in the adult brain. Since immature cells are generally more radiosensitive, here we investigated the effects of chronic low-dose radiation on cultured human neural progenitor cells (hNPCs) derived from embryonic stem cells. Radiation at low doses of 31, 124 and 496 mGy per 72 h was administered to hNPCs. The effects were estimated by gene expression profiling with microarray analysis as well as morphological analysis. Gene expression was dose-dependently changed by radiation. By thirty-one mGy of radiation, inflammatory pathways involving interferon signaling and cell junctions were altered. DNA repair and cell adhesion molecules were affected by 124 mGy of radiation while DNA synthesis, apoptosis, metabolism, and neural differentiation were all affected by 496 mGy of radiation. These in vitro results suggest that 496 mGy radiation affects the development of neuronal progenitor cells while altered gene expression was observed at a radiation dose lower than 100 mGy. This study would contribute to the elucidation of the clinical and subclinical phenotypes of impaired neuronal development induced by chronic low-dose radiation.

Hepatic transcriptomic responses to TCDD in dioxin-sensitive and dioxin-resistant rats during the onset of toxicity

International Nuclear Information System (INIS)

Boutros, Paul C.; Yao, Cindy Q.; Watson, John D.; Wu, Alexander H.; Moffat, Ivy D.; Prokopec, Stephenie D.; Smith, Ashley B.; Okey, Allan B.; Pohjanvirta, Raimo

2011-01-01

The dioxin congener 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes a wide range of toxic effects in rodent species, all of which are mediated by a ligand-dependent transcription-factor, the aryl hydrocarbon receptor (AHR). The Han/Wistar (Kuopio) (H/W) strain shows exceptional resistance to many TCDD-induced toxicities; the LD 50 of > 9600 μg/kg for H/W rats is higher than for any other wild-type mammal known. We previously showed that this resistance primarily results from H/W rats expressing a variant AHR isoform that has a substantial portion of the AHR transactivation domain deleted. Despite this large deletion, H/W rats are not entirely refractory to the effects of TCDD; the variant AHR in these animals remains fully competent to up-regulate well-known dioxin-inducible genes. TCDD-sensitive (Long-Evans, L-E) and resistant (H/W) rats were treated with either corn-oil (with or without feed-restriction) or 100 μg/kg TCDD for either four or ten days. Hepatic transcriptional profiling was done using microarrays, and was validated by RT-PCR analysis of 41 genes. A core set of genes was altered in both strains at all time points tested, including CYP1A1, CYP1A2, CYP1B1, Nqo1, Aldh3a1, Tiparp, Exoc3, and Inmt. Outside this core, the strains differed significantly in the breadth of response: three-fold more genes were altered in L-E than H/W rats. At ten days almost all expressed genes were dysregulated in L-E rats, likely reflecting emerging toxic responses. Far fewer genes were affected by feed-restriction, suggesting that only a minority of the TCDD-induced changes are secondary to the wasting syndrome.

Carcinogenicity of individual and a mixture of dioxin-like compounds in female Harlan Sprague Dawley rats

Energy Technology Data Exchange (ETDEWEB)

Walker, N.; Nyska, A. [National Institute of Environmental Health Sciences, Research Triangle Park, NC (United States); Crockett, P. [Constella Group, Research Triangle Park, NC (US)] (and others)

2004-09-15

The human health risk posed by exposure to persistent organochlorine pollutants (POPs), including polychlorinated-dioxins (PCDDs), -furans (PCDFs) and - biphenyls (PCBs), present in the food and the environment is one of widespread concern throughout the industrialized world. The dioxin Toxic Equivalency Factor (TEF) approach is currently the most feasible interim approach for assessing and managing the risk posed by exposure to mixtures of these compounds and has been formally adopted by regulatory bodies in many countries, the International Programme on Chemical Safety and the World Health Organization. The TEF methodology is a relative potency scheme that estimates the total exposure and biological effects of a mixture of chemicals based on a common mechanism of action involving an initial binding of the compound to the Aryl hydrocarbon receptor (AhR). An implicit assumption of the TEF methodology is that the combined risk of effects of the different congeners is dose additive. Therefore, the total dioxin toxic equivalents (TEQs) of a mixture of PCDDs, PCDFs, and PCBs may be estimated by the summation of the mass of each compound in the mixture after adjustment for its potency relative to that of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). While dose additivity is supported for certain mixtures for some biological endpoints in some experimental models, this has never been evaluated for cancer risk. Here we present a summary of four chronic rodent bioassay conducted by the National Toxicology Program (US Department of Health and Human Services) that evaluated the carcinogenicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3.3',4,4',5- pentachlorobiphenyl (PCB126) and 2,3,4,7,8 pentachlorodibenzofuran (PeCDF) and a mixture of these three dioxin-like compounds in female Harlan Sprague Dawley rats. Data from these studies will be used to test the hypothesis of dose-additivity of carcinogenicity by a defined mixture of dioxin-like compounds.

Biological influence from low dose and low-dose rate radiation

International Nuclear Information System (INIS)

Magae, Junji

2007-01-01

Although living organisms have defense mechanisms for radioadaptive response, the influence is considered to vary qualitatively and quantitatively for low dose and high dose, as well as for low-dose rate and high-dose rate. This article describes the bioresponse to low dose and low-dose rate. Among various biomolecules, DNA is the most sensitive to radiation, and accurate replication of DNA is an essential requirement for the survival of living organisms. Also, the influence of active enzymes resulted from the effect of radiation on enzymes in the body is larger than the direct influence of radiation on the body. After this, the article describes the carcinogenic risk by low-dose radiation, and then so-called Hormesis effect to create cancer inhibition effect by stimulating active physiology. (S.K.)

Low-dose/dose-rate γ radiation depresses neural differentiation and alters protein expression profiles in neuroblastoma SH-SY5Y cells and C17.2 neural stem cells.

Science.gov (United States)

Bajinskis, Ainars; Lindegren, Heléne; Johansson, Lotta; Harms-Ringdahl, Mats; Forsby, Anna

2011-02-01

The effects of low doses of ionizing radiation on cellular development in the nervous system are presently unclear. The focus of the present study was to examine low-dose γ-radiation-induced effects on the differentiation of neuronal cells and on the development of neural stem cells to glial cells. Human neuroblastoma SH-SY5Y cells were exposed to (137)Cs γ rays at different stages of retinoic acid-induced neuronal differentiation, and neurite formation was determined 6 days after exposure. When SH-SY5Y cells were exposed to low-dose-rate γ rays at the onset of differentiation, the number of neurites formed per cell was significantly less after exposure to either 10, 30 or 100 mGy compared to control cells. Exposure to 10 and 30 mGy attenuated differentiation of immature C17.2 mouse-derived neural stem cells to glial cells, as verified by the diminished expression of glial fibrillary acidic protein. Proteomic analysis of the neuroblastoma cells by 2D-PAGE after 30 mGy irradiation showed that proteins involved in neuronal development were downregulated. Proteins involved in cell cycle and proliferation were altered in both cell lines after exposure to 30 mGy; however, the rate of cell proliferation was not affected in the low-dose range. The radiation-induced attenuation of differentiation and the persistent changes in protein expression is indicative of an epigenetic rather than a cytotoxic mechanism.

Dioxin Exposure Initiative

Science.gov (United States)

The Dioxin Exposure Initiative (DEI) is no longer active. This page contains a summary of the dioxin exposure initiative with illustrations, contact and background information.Originally supported by scientist Matthew Lorber, who retired in Mar 2017.

Perinatal exposure to dioxins and dioxin-like compounds and infant growth and body mass index at seven years

DEFF Research Database (Denmark)

Iszatt, N.; Stigum, H; Govarts, Eva

2016-01-01

Background Dioxins and dioxin-like compounds are endocrine disrupting chemicals (EDCs). Experimental studies suggest perinatal exposure to EDCs results in later obesity. However, the few epidemiological investigations on dioxins are inconclusive. We investigated perinatal exposure to dioxins...... and dioxin-like compounds, infant growth and body mass index (BMI) in childhood. Methods We pooled data from 3 European birth cohorts (Belgian, Norwegian, Slovak) with exposure assessment in cord blood or breast milk. Two cohorts had dioxin-like toxicity assessed using dioxin-responsive chemical......-activated luciferase expression (DR-CALUX) bioassay and one cohort had measured concentrations of dioxins, furans and dioxin-like polychlorinated biphenols with CALUX relative potency values applied. Growth was cohort- and sex-specific change in weight-for-age z-score between birth and 24 months (N = 367). BMI...

Comparisons of dioxin levels of cucumber varieties and cultivation periods

Energy Technology Data Exchange (ETDEWEB)

Eun, H.; Watanabe, E.; Ishii, Y.; Ueji, M. [National Inst. for Agro-Environmental Sciences, Tsukuba (Japan); Narita, I.; Nakamura, K. [Saitama Prefecture Agriculture and Forestry Research Center, Saitama (Japan)

2004-09-15

According to a 2001 survey on Daily Intake in Japan, the total dioxins intake of a person in Japan amounts to 1.68 pg-TEQ per kg of body weight/day on average. The sharing a percentage of agricultural crops was about 3%in Japanese TDI amounts. However, all cases collect samples from supermarkets to estimate TDI of dioxins, which make it difficult to understand under what environment, food samples were pretreated and cultivated. Especially, TDI values in agricultural crops are probably dependent on the collection situation. In the agricultural environment, some reports indicate that dioxins have accumulated in paddy and upland in Japan due to the past use of some types of agricultural chemicals, which contained dioxins as impurities. Furthermore, taking the atmospheric pathway, for example, dioxins in the ambient air are associated with particulate matter and fall to the ground, contaminating agricultural land. Thus, it has been emphasized that dioxin compounds have a possibility to have adverse effect on vegetables. However, there is little understanding related to this fact in the country and worldwide. Empirical studies conducted in Japan and abroad have reported low residual concentrations of dioxins in cucumbers (Cucumis sativus L.), a member of the gourd family. However, there have been extremely few instances of research involving overall comparisons of cultivation environments. Thus, we studied the persistence of dioxins in cucumbers of different varieties cultivated outdoors over varying cultivation periods, conducting thorough experiments to elucidate the actual conditions and mechanisms of dioxin contamination of cucumbers.

Low-dose DNA adduct dosimetry by accelerator mass spectrometry (AMS)

International Nuclear Information System (INIS)

Turteltaub, K.W.; Felton, J.S.; Vogel, J.S.; Gledhill, B.L.; Davis, J.C.; Snyderwine, E.G.; Thorgeirsson, S.S.; Adamson, R.H.

1991-01-01

DNA adduction was measured following exposure to low doses of [2- 14 C]-2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) [2- 14 C]-2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and [U- 14 C]-2,3,7,8-tetrachlorodibenzo-p-dioxin by AMS, a technique used in the earth sciences but not previously in toxicological research. The ability to measure low concentrations of rare isotopes suggested that biomedical research was a potentially powerful application for this technology. Sensitivity of the method was found to be one adduct per 10 11 nucleotides. No DNA adduct formation could be detected in TCDD treated rodents. DNA adducts in cynomolgus monkey lymphocytes following exposure to 500 μg/kg IQ peaked between 6 and 18 hrs following exposure. Sensitivity was limited mainly by the abundance of 14 C in contemporary carbon. Hosts depleted in radiocarbon are being developed, potentially increasing sensitivity another 3 orders of magnitude. These results demonstrate the high sensitivity of AMS for tracing molecules following administration of low levels of isotopically-labeled xenobiotics. In addition to 14 C measurement, AMS offers potential to conduct studies with other isotopes, particularly 3 H and 41 Ca

A survey of dioxin-like contaminants in fish from recreational fishing.

Science.gov (United States)

Heimstad, Eldbjørg Sofie; Grønstøl, Gaute; Hetland, Karl Torstein; Alarcon, Javier Martinez; Rylander, Charlotta; Mariussen, Espen

2015-08-01

The dioxin and dioxin-like compounds are regarded as one of the most toxic group of environmental contaminants. Food for the commercial market is regularly monitored for their dioxin levels and the concentration allowed in food is strictly regulated. Less is known about locally caught fish from recreational fishing, which is often brought home for consumption. This can be fish caught from nearby lakes or streams or fish with marine origin close to industrial areas or harbours that are not regularly monitored for their dioxin levels. In this study, we established collaboration with schools in 13 countries. We received 203 samples of 29 different fish species of which Atlantic cod was the most abundant followed by brown trout and pollock. In general, the majority of samples from the participating countries had low concentrations (between 0.1 and 0.2 pg/g chemical-activated luciferase gene expression toxic equivalency wet weight (CALUX TEQ w.w.)) of dioxins and dioxin-like PCBs. Only 18 samples had concentrations above 1 pg/g CALUX TEQ w.w., and only 2 dab samples had concentration above maximum levels set by the European Commission. The Atlantic cod samples showed a significant reduction in the concentrations of dioxins with increasing latitude indicating less contamination of dioxin and dioxin-like compounds in the north of Norway. The results indicate that a moderate consumption of self-caught fish at presumed non-contaminated sites does not represent a major risk for exposure to dioxins or dioxin-like compounds at concentrations associated with adverse health effects. Recreational fishermen should, however, obtain knowledge about local fish consumption advice.

Automated rapid analysis for dioxins and PCBs in food, feedingstuff and environmental matrices

Energy Technology Data Exchange (ETDEWEB)

Hoelscher, K.; Maulshagen, A.; Behnisch, P.A. [eurofins-GfA, Muenster (Germany); Shirkhan, H. [Fluid Management Systems Inc., Waltham, MA (United States); Lieck, G. [University of Applied Science, Steinfurt (Germany)

2004-09-15

Today there is a need to develop high throughput specific and sensitive methods for the determination of dioxins, dioxin-like PCBs and indicator-PCBs to ensure their rapid and reliable quantification in several kinds of food and feedingstuffs. Ideally one method would fit for several matrices with highest quality standards and with the possibility of a cost/time-effective samplehandling. However, generally in case of the numerous different PCDD/Fs, dioxin-like PCBs and indicator-PCBs as well as the large concentration range to cover this is quite difficult to fulfill. The implementation of an automated sample-treatment flow process (''dioxin street''), which contains an accelerated solvent extraction (ASE), a Power-Prep workstation (Fluid Management Systems, FMS) for automated clean-up, a Syncore Polyvap (Buechi, Switzerland) for solvent evaporation and a HRGC/HRMS (VG AutoSpec) analysis as detection method for several kinds of different matrices is described here. The aim of the present study is to confirm the high quality, low limits of quantification (LOQ), low PCB background levels and reliability of the Power-Prep system in combination with ASE extraction for dioxins, dioxin-like PCBs and indicator-PCBs.

Dioxin in Danish air

Energy Technology Data Exchange (ETDEWEB)

Vikelsoe, J.; Andersen, H.V. [National Environmental Research Inst., Roskilde (Denmark)

2004-09-15

To gain more knowledge about dioxin levels, sources and emissions in Denmark, the Danish government year 2001 initiated the Danish Dioxin Monitoring Program. The program is a series of investigations, comprising soil, compost, percolate, bio-ash, incineration of municipal and hazardous waste, deposition, air, lake and fjord sediment as well as cows milk and human milk. The present paper describes the preliminary results for the continued investigation of air. Deposition of dioxin over land or sea is of major importance for the human exposure, which takes place mainly from food intake. The dioxin are emitted mainly to the atmosphere, therefore air measurements are well suited for tracking the transport and fate of dioxin from sources to exposure. Whereas measurements from chimneys has been frequently used to estimate the industrial emission from point sources such as incinerators, air measurements also include emission from diffuse sources such as larger urban or industrial regions, residential quarters, and from evaporation. Furthermore, emission measurements must be done on known sources, whereas air measurements include contribution from unknown source. The major drawbacks of air measurements are the long duration required (years), and the results depends on meteorological conditions, such as temperature, rainfall, wind speed and direction. The purpose of the present study has been to measure dioxins in Danish air, emphasizing - background concentrations and annual variation - difference between urban, rural and residential zones - influence from local sources and long range transport - connection between dioxin in air and deposition.

Environmental pollution by dioxin and its biodegradation; Dioxin ni yoru kankyo osen to sono biseibutsu bunkai

Energy Technology Data Exchange (ETDEWEB)

Nojiri, H.; Yamane, H.; Omori, T. [Tokyo Univ. (Japan)

1998-10-20

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (Co-PCBs) exhibit similar chemical and biological properties. Because of their highly toxic activity, the pollution with these compounds, which are called dioxin-related compounds, is one of the most serious environmental problems. In this review, we described the analytical methods of dioxin-related compounds in environmental samples, especially in the exhaust gas from the incineration site of municipal solid waste. In addition, we described the present situation of environmental pollution by dioxin-related compounds, including pollution levels in environmental, human, and food samples, daily intakes, and risk assessment. On the other hand, a number of microorganisms have been reported which are able to degrade dioxin-related compounds including PCDDs and PCDFs. These microorganisms are classified into two groups, lignin-degrading white rot fungi and the dioxin-degrading bacteria. We also described the degradation pathways of dioxin-related compounds in these microorganisms, and their degradative enzymes. 47 refs., 5 figs., 4 tabs.

Concentrations of dioxins and dioxine-like PCBs in feed material in the Netherlands, 2001-11

NARCIS (Netherlands)

Adamse, P.; Fels-Klerx, van der H.J.; Schoss, S.; Jong, de J.; Hoogenboom, L.A.P.

2015-01-01

This study aimed to obtain insights into contamination of feed materials used in the Netherlands with dioxins (polychlorinated dibenzo-p-dioxins and dibenzofurans) and dioxin-like polychlorinated biphenyls (PCBs). Monitoring results from the period 2001-11, covering in total 4938 samples, were

Global deposition of airborne dioxin.

Science.gov (United States)

Booth, Shawn; Hui, Joe; Alojado, Zoraida; Lam, Vicky; Cheung, William; Zeller, Dirk; Steyn, Douw; Pauly, Daniel

2013-10-15

We present a global dioxin model that simulates one year of atmospheric emissions, transport processes, and depositions to the earth's terrestrial and marine habitats. We map starting emission levels for each land area, and we also map the resulting deposits to terrestrial and marine environments. This model confirms that 'hot spots' of deposition are likely to be in northern Europe, eastern North America, and in parts of Asia with the highest marine dioxin depositions being the northeast and northwest Atlantic, western Pacific, northern Indian Ocean and the Mediterranean. It also reveals that approximately 40% of airborne dioxin emissions are deposited to marine environments and that many countries in Africa receive more dioxin than they produce, which results in these countries being disproportionately impacted. Since human exposure to dioxin is largely through diet, this work highlights food producing areas that receive higher atmospheric deposits of dioxin than others. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dioxin and dioxin-like PCB exposure of non-breastfed Dutch infants.

NARCIS (Netherlands)

Weijs, P J M; Bakker, Martine I; Korver, K R; Goor Ghanaviztchi, K van; Wijnen, Joop H van

2006-01-01

The exposure of humans to PCDD/Fs (polychlorinated dibenzo-p-dioxins and dibenzofurans) and dioxin-like PCBs (dl-PCBs, i.e. polychlorinated non-ortho and mono-ortho biphenyls) occurs predominantly via the intake of food. Young children have a relatively high intake of these substances, due to their

Low doses effects and gamma radiations low dose rates

International Nuclear Information System (INIS)

Averbeck, D.

1999-01-01

This expose wishes for bringing some definitions and base facts relative to the problematics of low doses effects and low dose rates effects. It shows some already used methods and some actual experimental approaches by focusing on the effects of ionizing radiations with a low linear energy transfer. (N.C.)

Size fractionation of waste-to-energy boiler ash enables separation of a coarse fraction with low dioxin concentrations.

Science.gov (United States)

Weidemann, E; Allegrini, E; Fruergaard Astrup, T; Hulgaard, T; Riber, C; Jansson, S

2016-03-01

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) formed in modern Waste-to-Energy plants are primarily found in the generated ashes and air pollution control residues, which are usually disposed of as hazardous waste. The objective of this study was to explore the occurrence of PCDD/F in different grain size fractions in the boiler ash, i.e. ash originating from the convection pass of the boiler. If a correlation between particle size and dioxin concentrations could be found, size fractionation of the ashes could reduce the total amount of hazardous waste. Boiler ash samples from ten sections of a boiler's convective part were collected over three sampling days, sieved into three different size fractions - 0.355 mm - and analysed for PCDD/F. The coarse fraction (>0.355 mm) in the first sections of the horizontal convection pass appeared to be of low toxicity with respect to dioxin content. While the total mass of the coarse fraction in this boiler was relatively small, sieving could reduce the amount of ash containing toxic PCDD/F by around 0.5 kg per tonne input waste or around 15% of the collected boiler ash from the convection pass. The mid-size fraction in this study covered a wide size range (0.09-0.355 mm) and possibly a low toxicity fraction could be identified by splitting this fraction into more narrow size ranges. The ashes exhibited uniform PCDD/F homologue patterns which suggests a stable and continuous generation of PCDD/F. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dioxins, furans and dioxin-like PCBs in human blood: causes or consequences of diabetic nephropathy?

Science.gov (United States)

Everett, Charles J; Thompson, Olivia M

2014-07-01

Nephropathy, or kidney disease, is a major, potential complication of diabetes. We assessed the association of 6 chlorinated dibenzo-p-dioxins, 9 chlorinated dibenzofurans and 8 polychlorinated biphenyls (PCBs) in blood with diabetic nephropathy in the 1999-2004 National Health and Nutrition Examination Survey (unweighted N=2588, population estimate=117,658,357). Diabetes was defined as diagnosed or undiagnosed (glycohemoglobin ≥ 6.5%) and nephropathy defined as urinary albumin to creatinine ratio >30 mg/g, representing microalbuminuria or macroalbuminuria. For the 8 chemicals analyzed separately, values above the 75th percentile were considered elevated, whereas for the other 15 compounds values above the maximum limit of detection were considered elevated. Seven of 8 dioxins and dioxin-like compounds, analyzed separately, were found to be associated with diabetic nephropathy. The chemicals associated with diabetic nephropathy were: 1,2,3,6,7,8-Hexachlorodibenzo-p-dioxin; 1,2,3,4,6,7,8,9-Octachlorodibenzo-p-dioxin; 2,3,4,7,8-Pentachlorodibenzofuran; PCB 126; PCB 169; PCB 118; and PCB 156. Three of the 8 dioxins and dioxin-like compounds; 1,2,3,4,6,7,8,9-Octachlorodibenzo-p-dioxin; 2,3,4,7,8-Pentachlorodibenzofuran and PCB 118; expressed as log-transformed continuous variables; were associated with diabetes without nephropathy. When 4 or more of the 23 chemicals were elevated the odds ratios were 7.00 (95% CI=1.80-27.20) for diabetic nephropathy and 2.13 (95% CI=0.95-4.78) for diabetes without nephropathy. Log-transformed toxic equivalency (TEQ) was associated with both diabetic nephropathy, and diabetes without nephropathy, the odds ratios were 2.35 (95% CI=1.57-3.52) for diabetic nephropathy, and 1.44 (95% CI=1.11-1.87) for diabetes without nephropathy. As the kidneys function to remove waste products from the blood, diabetic nephropathy could be either the cause or the consequence (or both) of exposure to dioxins, furans and dioxin-like PCBs. Copyright © 2014

Quantitative phosphoproteomic analysis of early alterations in protein phosphorylation by 2,3,7,8-tetrachlorodibenzo-p-dioxin

DEFF Research Database (Denmark)

Schulz, Melanie; Brandner, Stefanie; Eberhagen, Carola

2013-01-01

A comprehensive quantitative analysis of changes in protein phosphorylation preceding or accompanying transcriptional activation by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in 5L rat hepatoma cells was performed using the SILAC approach. Following exposure of the cells to DMSO or 1 nM TCDD for 0......-induced gene activation, regulators of small GTPases of the Ras superfamily, UBX domain-containing proteins and the oncogenic protein LYRIC. The results open up new directions for research on the molecular mechanisms of dioxin action and toxicity....

Fruit-flies in low-dose exposure experiments

International Nuclear Information System (INIS)

Zajnullin, V.G.; Moskalev, A.A.; Shaposhnikov, M.V.; Sheptyakova, A.I.

2002-01-01

In vivo exposure of fruit-flies of Drosophila melanogaster line to low doses provided new data indicating that mechanisms of induced genetic instability are involved in radiation-induced alteration of genotype. It is true for increase of genetic variance due to change in transposition number, for change in adaptation capabilities due to modification of gene expression, and for mutability-associated reparation and apoptosis. (author)

Screening by microarray analysis for genes that alter prostate development in C57BL/6J mice exposed in utero to 2,3,7,8-tetrachlorodibenzo-p-dioxin

Energy Technology Data Exchange (ETDEWEB)

Ohsako, Seiichiroh; Lin, Tienmin; Peterson, R.E. [Wisconsin Univ. (United States); Suzuki, Junko S.; Wu, Qing; Tohyama, Chiharu [National Institute for Environmental Studies, Tsukuba (Japan); Takei, Teiji [Ministry of the Environment, Tokyo (Japan)

2004-09-15

The administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to pregnant rats and mice leads to a disruption of prostate development in the male offspring. Although it is not clear if this phenomenon occurs in human populations exposed to TCDD, the observed effect level is low among the various endpoints of TCDD developmental toxicity in animal studies. Clarification of the mechanism by which the effect is produced at the molecular level would help substantiate male reproductive toxicity caused by in utero TCDD exposure as a model for human health risk assessment. In both rats and mice, a critical window for TCDD disruption of prostate development in late pregnancy has been illustrated. The primary alteration in gene expression that presumably causes this phenomenon depends on the fetal aryl hydrocarbon receptor gene being expressed in the fetal urogenital sinus from which the outgrowth of prostatic buds occurs. In the male offspring of mice exposed to TCDD on gestation day 13 (GD 13), severe inhibitory developmental effects were found on ventral prostate development. These effects were significantly lower when in utero TCDD exposure occurred after GD 16 than GD 13. Upon administration of TCDD to the dam on GD 13, cytochrome P450 1A1 (CYP1A1) and CYP1B1 were induced in the urogenital complex of the male offspring on postnatal day 14. Thus, ''dioxin biomarker genes'' are responsive to in utero and lactational TCDD exposure during the neonatal stage of development. This suggests that key TCDD responsive genes involved in disrupting prostate development would be genes other than CYP1A1 and CYP1B1. In the present study we administered a single dose of TCDD to mouse dams during the critical window (GD 13 or GD 14) for impairing prostate development, or later during a less TCDD sensitive period (GD 17). Microarray techniques were then used to compare gene expression profiles of the fetus versus the urogenital sinus in order to identify genes

Health effect of low dose/low dose rate radiation

International Nuclear Information System (INIS)

Kodama, Seiji

2012-01-01

The clarified and non-clarified scientific knowledge is discussed to consider the cause of confusion of explanation of the title subject. The low dose is defined roughly lower than 200 mGy and low dose rate, 0.05 mGy/min. The health effect is evaluated from 2 aspects of clinical symptom/radiation hazard protection. In the clinical aspect, the effect is classified in physical (early and late) and genetic ones, and is classified in stochastic (no threshold value, TV) and deterministic (with TV) ones from the radioprotection aspect. Although the absence of TV in the carcinogenic and genetic effects has not been proved, ICRP employs the stochastic standpoint from the safety aspect for radioprotection. The lowest human TV known now is 100 mGy, meaning that human deterministic effect would not be generated below this dose. Genetic deterministic effect can be observable only in animal experiments. These facts suggest that the practical risk of exposure to <100 mGy in human is the carcinogenesis. The relationship between carcinogenic risk in A-bomb survivors and their exposed dose are found fitted to the linear no TV model, but the epidemiologic data, because of restriction of subject number analyzed, do not always mean that the model is applicable even below the dose <100 mGy. This would be one of confusing causes in explanation: no carcinogenic risk at <100 mGy or risk linear to dose even at <100 mGy, neither of which is scientifically conclusive at present. Also mentioned is the scarce risk of cancer in residents living in the high background radiation regions in the world in comparison with that in the A-bomb survivors exposed to the chronic or acute low dose/dose rate. Molecular events are explained for the low-dose radiation-induced DNA damage and its repair, gene mutation and chromosome aberration, hypothesis of carcinogenesis by mutation, and non-targeting effect of radiation (bystander effect and gene instability). Further researches to elucidate the low dose

In utero exposure to dioxins and dioxin-like compounds and anogenital distance in newborns and infants.

Science.gov (United States)

Vafeiadi, Marina; Agramunt, Silvia; Papadopoulou, Eleni; Besselink, Harrie; Mathianaki, Kleopatra; Karakosta, Polyxeni; Spanaki, Ariana; Koutis, Antonis; Chatzi, Leda; Vrijheid, Martine; Kogevinas, Manolis

2013-01-01

Anogenital distance in animals is used as a measure of fetal androgen action. Prenatal exposure to dioxins and dioxin-like compounds in rodents causes reproductive changes in male offspring and decreases anogenital distance. We assessed whether in utero exposure to dioxins and dioxin-like compounds adversely influences anogenital distance in newborns and young children (median age, 16 months; range, 1-31 months). We measured anogenital distance among participants of the "Rhea" mother-child cohort study in Crete and the Hospital del Mar (HMAR) cohort in Barcelona. Anogenital distance (AGD; anus to upper penis), anoscrotal distance (ASD; anus to scrotum), and penis width (PW) were measured in 119 newborn and 239 young boys; anoclitoral (ACD; anus to clitoris) and anofourchetal distance (AFD; anus to fourchette) were measured in 118 newborn and 223 young girls. We estimated plasma dioxin-like activity in maternal blood samples collected at delivery with the Dioxin-Responsive Chemically Activated LUciferase eXpression (DR CALUX®) bioassay. Anogenital distances were sexually dimorphic, being longer in males than females. Plasma dioxin-like activity was negatively associated with AGD in male newborns. The estimated change in AGD per 10 pg CALUX®-toxic equivalent/g lipid increase was -0.44 mm (95% CI: -0.80, -0.08) after adjusting for confounders. Negative but smaller and nonsignificant associations were observed for AGD in young boys. No associations were found in girls. Male infants may be susceptible to endocrine-disrupting effects of dioxins. Our findings are consistent with the experimental animal evidence used by the Food and Agriculture Organization/World Health Organization to set recommendations for human dioxin intake.

The dioxins in broad daylight; Les dioxines au grand jour

Energy Technology Data Exchange (ETDEWEB)

Claveri, B.; Mersch, J. [BioMonitor, 57 - Florange (France)

2001-07-01

In the framework of the Eco-Industries 2000 meeting, the ATEE organized a colloquium on the dioxins in the environment. This book presents the seven papers proposed at this colloquium bringing information on the dioxins and the furans molecular structure, their biological impacts on the environment, the monitoring and regulations in the domain and some example of remedial actions in the metal and wood industry. (A.L.B.)

Influence of dioxin intoxication on the human system and possibilities of limiting its negative effects on the environment and living organisms

Directory of Open Access Journals (Sweden)

Ireneusz Całkosiński

2014-09-01

Full Text Available [b]Introduction and objective[/b]. Despite the restrictive legal regulations related to the reduction of dioxins emission, their concentration in the environment is still too high. Mainly, this is related to the illegal utilisation of electronic equipment and combustion of wastes, and also to intensified activity and maintenance of ships, especially in developing countries. The most important remaining source in Europe is the metal industry. Studies on the mechanism of impact of dioxins are still being carried out. This review points at new possibilities for limiting the molecular mechanisms of dioxins activity, inter alia, through the application of high doses of tocopherol and acetylsalicylic acid while treating dioxins intoxication. [b]Brief description of the state of knowledge. [/b]Apart from the knowledge of dioxins affinity to the aryl hydrocarbon receptor (AhR, the multi-stage radical-form actions and the pro-inflammatory mechanism associated with cyclooxygenase-II enzyme (COX-2 are under intense investigation at the moment. Due to the high affinity of dioxins to animals adipose tissue and their ability to accumulate in it, they can enter the food chain. Furthermore, high dioxin doses can cause poisoning manifested as advanced clinical symptoms, whereas in smaller doses, when cumulated, can cause metabolic changes which are often difficult to associate with their presence. Recently, some serious food contaminations by dioxins have been demonstrated. Sea fish and products from contaminated aqueducts still constitute potential sources of dioxins pollution. [b]Conclusion.[/b] According to recent studies, dioxins are present in different concentrations in the environment and cause specific and long-time effects. These effects could be limited by the use of tocopherol and acetylsalicylic acid.

Research on low radiation doses - A better understanding of low doses

International Nuclear Information System (INIS)

2016-01-01

Radiation doses below 100 mSv are called low doses. Epidemiological research on the health hazards of low doses are difficult to do because numerous pathologies, particularly cancer, appear lifelong for genetical or environmental causes without any link with irradiation and it is very difficult to identify the real cause of a cancer. Another concern is that the impact on human health is weak and are observed only after a long period after irradiation. These features make epidemiological studies cumbersome to implement since they require vast cohorts and a very long-term follow-up. The extrapolation of the effects of higher doses to the domain of low doses does not meet reality and it is why the European Union takes part into the financing of such research. In order to gain efficiency, scientists work together through various European networks among them: HLEG (High Level Expert Group On European Low Dose Risk Research) or MELODI (Multidisciplinary European Low Dose Initiative). Several programs are underway or have been recently launched: -) the impact of Cesium contamination on children's health (Epice program), -) the study of the impact of medical imaging on children, -) the study of the health of children living near nuclear facilities, -) the relationship between radon and lung cancer, -) the effect of occupational low radiation doses, -) the effect of uranium dissolved in water on living organisms (Envirhom program). (A.C.)

Levels of polychlorinated dibenzo(p)dioxins, dibenzofurans and dioxin-like PCBs in Irish farmed salmon

Energy Technology Data Exchange (ETDEWEB)

Gruemping, R.; Hamm, S.; Stegemann, D.; Maulshagen, A. [eurofins/GfA, Muenster (Germany)

2004-09-15

A recent survey published by Hites in the journal Science compared the level of organochlorine contaminants including PCBs and dioxins in farmed versus wild salmon collected from around the world. Most organochlorine substances analysed in the study show a significantly higher concentration level in farmed than in wild salmon. While dioxin and PCB levels of wild fish mainly reflect the contamination level of the environment in which the fish is grown, the dioxin and PCB concentration in farmed fish may mainly be attributed to the fish feed used. In January 2004, the Irish Sea Fisheries Board (BIM) conducted the present study on the concentration of Polychlorinated Dibenzo(p)dioxins (PCDDs), Dibenzofurans (PCDFs) and dioxinlike PCBs (WHO-PCBs) in farmed salmon from two locations in Ireland. The present study should examine whether the PCDD/F and WHO-PCB levels of Irish farmed salmon correlate to the dioxin data for farmed Atlantic salmon from other countries in Northern Europe (e.g. Scotland, Faroe Islands and Norway) presented in the study by Hites. In the Hites survey, raw salmon filets with skin on were tested. Since PCBs, dioxins and other organic pollutants are mainly bound to the fish fat, a reduction of fat content by removal of the skin was supposed to lower the amount of organic contaminants. Thus, the effect of skin removal on the dioxin and PCB levels was also examined in the present study. In addition, the influence of cooking the fish meat was investigated.

Contamination of free-range chicken eggs with dioxins and dioxin-like polychlorinated biphenyls

NARCIS (Netherlands)

Schoeters, G.; Hoogenboom, L.A.P.

2006-01-01

Dioxins and dioxin-like (DL) polychlorinated biphenyls (PCB) are persistent organic pollutants that enter the body mainly by food intake. A small margin exists between current exposure levels in the human population and the levels causing biological effects. Therefore, stringent control of

Impact of Perinatal Dioxin Exposure on Infant Growth: A Cross-Sectional and Longitudinal Studies in Dioxin-Contaminated Areas in Vietnam

Science.gov (United States)

Nishijo, Muneko; Tai, Pham The; Nakagawa, Hideaki; Maruzeni, Shoko; Anh, Nguyen Thi Nguyet; Van Luong, Hoang; Anh, Tran Hai; Honda, Ryumon; Morikawa, Yuko; Kido, Teruhiko; Nishijo, Hisao

2012-01-01

Dioxin exposure levels remain elevated in residents living around former US Air Force bases in Vietnam, indicating potential adverse impacts on infant growth. In this study, 210 mother–infant pairs in dioxin-contaminated areas in Vietnam were recruited at the infants’ birth and followed up for 4 months. Perinatal dioxin exposure levels were estimated by measurement of polychlorinated dibenzo-p-dioxins/furans toxic equivalent (PCDDs/Fs-TEQ) in breast milk. The infants’ size was measured at birth and 1 and 4 months after birth, and neurodevelopment was evaluated using the Bayley Scales III at 4 months of age. Among 4 dioxin groups (dioxin levels. Only in boys, cognitive, language, and fine motor scores in the ≥75 percentile group were significantly lower than those in the other groups. These results suggested a considerable impact of perinatal dioxin exposure on infant growth, particularly in boys exposed to dioxins at high level of PCDDs/Fs-TEQ. PMID:22815734

Investigation on main source of dioxin analogues in human breast milk (second report)

Energy Technology Data Exchange (ETDEWEB)

Miyata, H.; Nakao, T.; Aozasa, O.; Ohta, S. [Setsunan Univ., Hirakata (Japan); Iwamatsu, T. [Teijin Eco Science, Co. Ltd., Matsuyama (Japan); Fujimine, Y. [Otsuka Pharmaceutical Co. Ltd., Tokushima (Japan); Fukui, S. [Fukui Lactation Consultation, Amagasaki (Japan)

2004-09-15

In many countries, the breast milk sample has been used as a suitable indicator in order to examine human exposure level to Dioxins. In general, the breast milk level is considered to be reflecting to their accumulation level in the body. In addition, it is considered that ca. 60% of the accumulation amount of Dioxins is excreted to the baby through breast milk by nursing for a year. However, are these things true? In 1989, Frust et al. reported a time course of concentrations of Dioxins (abbreviated as Dioxins) in breast milk of one German during a period of 1 - 60 weeks after delivery. In the case of PCDFs, the level of 10 - 13 weeks after delivery was remarkably higher than that of 5 weeks. In addition, the PCBs level on the 10 to 13 weeks was also higher in comparison with on the 1 week. Thus, their pollution levels did not always decrease with a passing of time after childbirth. This suggests that all Dioxins in breast milk might be not derived from their storage in the body. Therefore, in 2001, we investigated the time alteration on the pollution level of Dioxins in breast milk from nine mothers and on their infants' daily intake of Dioxins by nursing. Consequently, it was revealed that the average daily intake of PCDD/DFs (PCDDs + PCDFs) was roughly constant during a period of 5 to 180 days after delivery. If all PCDD/DFs in breast milk are derived from only their body storage, the pollution level in milk must decrease in a linear course during a period of 5 to 180 days after delivery. However, thus linear decrease of pollution level was not observed in all tested mothers. These results indicated that PCDD/DFs in milk might be also delivered from other sources except for their storage in the body. Therefore, in this study, we tried to investigate the source of Dioxins in human breast milk.

Dietary exposure to dioxins and dioxin-like PCBs of Hong Kong adults: results of the first Hong Kong Total Diet Study.

Science.gov (United States)

Wong, Waiky W K; Yip, Yiu-chung; Choi, Koon-kay; Ho, Y Y; Xiao, Ying

2013-01-01

Dioxins and dioxin-like polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) covered by the Stockholm Convention on POPs. To assess the associated health risk of the Hong Kong population, the dietary exposure of the Hong Kong population and various age-gender subgroups to dioxins and dioxin-like PCBs was estimated in the first Hong Kong Total Diet Study (TDS), where food samples were collected and prepared "as consumed". A total of 142 composite food samples, mainly foods of animal origin and their products and oily food, were analysed for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and dioxin-like PCBs by the high-resolution gas chromatograph/high-resolution mass spectrometer (HRGC/HRMS) system. Dietary exposures were estimated by combining the analytical results with the food consumption data of Hong Kong adults. The mean and 95th percentile exposures to dioxins and dioxin-like PCBs of the Hong Kong population were 21.9 and 59.7 pg toxic equivalent (TEQ) kg⁻¹ body weight (bw) month⁻¹ respectively, which amounted to 31.3% and 85.2% of the provisional tolerable monthly intake (PTMI). The main dietary source of dioxins and dioxin-like PCBs was "Fish and seafood and their products" (61.9% of the total exposure), followed by "Meat, poultry and game and their products" (20.0%) and "Mixed dishes" (6.95%). The study findings suggest that the Hong Kong population is unlikely to experience the major undesirable health effects of dioxins and dioxin-like PCBs.

Exposure assessment of dioxins and dioxin-like PCBs in pasteurised bovine milk using probabilistic modelling.

Science.gov (United States)

Adekunte, Adefunke O; Tiwari, Brijesh K; O'Donnell, Colm P

2010-09-01

Quantitative exposure assessment is a useful technique to investigate the risk from contaminants in the food chain. The objective of this study was to develop a probabilistic exposure assessment model for dioxins (PCDD/Fs) and dioxin-like PCBs (DL-PCBs) in pasteurised bovine milk. Mean dioxins and DL-PCBs (non-ortho and mono-ortho PCBs) concentrations (pg WHO-TEQ g(-1)) in bovine milk were estimated as 0.06 ± 0.07 pg WHO-TEQ g(-1) for dioxins and 0.08 ± 0.07 pg WHO-TEQ g(-1) for DL-PCBs using Monte Carlo simulation. The simulated model estimated mean exposure for dioxins was 0.19 ± 0.29 pg WHO-TEQ kg(-1)bw d(-1) and 0.14 ± 0.22 pg WHO-TEQ kg(-1) bw d(-1) and for DL-PCBs was 0.25 ± 0.30 pg WHO-TEQ kg(-1) bw d(-1) and 0.19 ± 0.22 pg WHO-TEQ kg(-1) bw d(-1) for men and women, respectively. This study showed that the mean dioxins and DL-PCBs exposure from consumption of pasteurised bovine milk is below the provisional maximum tolerable monthly intake of 70 pg TEQ kg(-1) bw month(-1) (equivalent of 2.3 pg TEQ kg(-1) bw d(-1)) recommended by the Joint FAO/WHO Expert Committee on Food Additives and Contaminants (JECFA). Results from this study also showed that the estimated dioxins and DL-PCBs concentration in pasteurised bovine milk is comparable to those reported in previous studies. Copyright © 2010 Elsevier Ltd. All rights reserved.

Key enzymes of gluconeogenesis are dose-dependently reduced in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-treated rats

Energy Technology Data Exchange (ETDEWEB)

Weber, L.W.D.; Rozman, K. (Kansas Univ., Kansas City, KS (USA). Dept. of Pharmacology, Toxicology and Therapeutics Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen (GSF), Neuherberg (Germany, F.R.). Inst. fuer Toxikologie); Lebofsky, M. (Kansas Univ., Kansas City, KS (USA). Dept. of Pharmacology, Toxicology and Therapeutics); Greim, H. (Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen (GSF), Neuherberg (Germany, F.R.). Inst. fuer Toxikologie)

1991-02-01

Male Sprague-Dawley rats (240-245 g) were dosed ip with 5, 15, 25, or 125 {mu}g/kg -,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in corn oil. Ad libitum-fed and pair-fed controls received vehicle (4 ml/kg) alone. Two or 8 days after dosing five rats of each group were sacrificed, their livers removed and assayed for the activities of three gluconeogenic enzymes, (phosphoenol-pyruvate carboxykinase (PEPCK; EC 4.1.1.32), pyruvate carboxylase (PC; EC 6.4.1.1.), and glucose-6-phosphatase (G-6-Pase, EC 3.1.3.9)), and one glycolytic enzyme (pyruvate kinase (PK; EC 2.7.1.40)) by established procedures. The activity of PK was not affected by TCDD at either time point. The activity of G-6-Phase tended to be decreased in TCDD-treated animals, as compared to pair-fed controls, but the decrease was variable without an apparent dose-response. The activity of PEPCK was significantly decreased 2 days after dosing, but a clear dose-response was apparent only at the 8-day time point. Maximum loss of activity at the highest dose was 56% below pair-fed control levels. PC activity was slightly decreased 2 days after TCDD treatment and displayed statistically significant, dose-dependent reduction by 8 days after dosing with a 49% loss of enzyme activity after the highest dose. It is concluded that inhibition of gluconeogenesis by TCDD previously demonstrated in vivo is probably due to decreased activities of PEPCK and PC. The data also support the prevailing view that PEPCK and PC are rate-determining enzymes in gluconeogenesis. (orig.).

Dietary exposure to dioxins and dioxin-like PCBs in The Netherlands anno 2004

NARCIS (Netherlands)

Mul, de A.; Bakker, M.I.; Zeilmaker, M.J.; Traag, W.A.; Leeuwen, van S.P.J.; Hoogenboom, L.A.P.; Boon, P.E.; Klaveren, van J.D.

2008-01-01

In this study, representative occurrence data for PCDD/Fs and dioxin-like PCBs in food were obtained and used to estimate dietary exposure of the Dutch population. Food composite samples were analyzed as well as single fish and vegetables samples. Total dioxin concentrations in animal products

Physiological and immunological changes following exposure to low versus high-dose ionizing irradiation; comparative analysis with dose rate and cumulative dose

International Nuclear Information System (INIS)

Heesun, Kim; Heewon, Jang; Soungyeon, Song; Shinhye, Oh; Cukcheul, Shin; Meeseon, Jeong; Chasoon, Kim; Kwnaghee, Yang; Seonyoung, Nam; Jiyoung, Kim; Youngwoo, Jin; Changyoung, Cha

2008-01-01

Full text: While high-dose of ionizing radiation is generally harmful and causes damage to living organisms some reports suggest low-dose of radiation may not be as damaging as previously thought. Despite increasing evidence regarding the protective effect of low-dose radiation, no studies have directly compared the exact dose-response pattern by high- and low-dose of radiation exposed at high-and low-dose rate. This study aims to explore the cellular and molecular changes in mice exposed to low- and high-dose of radiation exposed at low- and high-dose rate. When C57BL/6 mice (Female, 6 weeks) were exposed at high-dose rate, 0.8 Gy/min, no significant change on the level of WBC, RBC, or platelets was observed up to total dose of 0.5 Gy. However, 2 Gy of radiation caused dramatic reduction in the level of white blood cells (WBC) and platelets. This reduction was accompanied by increased DNA damage in hematopoietic environments. The reduction of WBC was mainly due to the reduction in the number of CD4+ T cells and CD19+ B cells. CD8+ T cells and NK cells appeared to be relatively resistant to high-dose of radiation. This change was also accompanied by the reduction of T- and B- progenitor cells in the bone marrow. In contrast, no significant changes of the number of CD4+ T, CD8+ T, NK, and B cells were observed in the spleen of mice exposed at low-dose-rate (0.7 m Gy/h or 3.95 mGy/h) for up to 2 Gy, suggesting that low-dose radiation does not alter cellular distribution in the spleen. Nevertheless, mice exposed to low-dose radiation exhibited elevation of VEGF, MCP-1, IL-4, Leptin, IL-3, and Tpo in the peripheral blood and slight increases in MIP-2, RANTES, and IL-2 in the spleen. This suggests that chronic γ-radiation can stimulate immune function without causing damage to the immune components of the body. Taken together, these data indicate hormesis of low-dose radiation, which could be attributed to the stimulation of immune function. Dose rate rather than total

Maternal dietary intake of dioxins and polychlorinated biphenyls and birth size in the Norwegian Mother and Child Cohort Study (MoBa).

Science.gov (United States)

Papadopoulou, Eleni; Caspersen, Ida H; Kvalem, Helen E; Knutsen, Helle K; Duarte-Salles, Talita; Alexander, Jan; Meltzer, Helle Margrete; Kogevinas, Manolis; Brantsæter, Anne Lise; Haugen, Margaretha

2013-10-01

Maternal diet not only provides essential nutrients to the developing fetus but is also a source of prenatal exposure to environmental contaminants. We investigated the association between dietary intake of dioxins and PCBs during pregnancy and birth size. The study included 50,651 women from the Norwegian Mother and Child Cohort Study (MoBa). Dietary information was collected by FFQs and intake estimates were calculated by combining food consumption and food concentration of dioxins, dioxin-like PCBs and non-dioxin-like PCBs. We used multivariable regression models to estimate the association between dietary intake of dioxins and PCBs and fetal growth. The contribution of fish and seafood intake during pregnancy was 41% for dietary dioxins and dioxin-like PCBs and 49% for dietary non-dioxin-like PCBs. Further stratified analysis by quartiles of seafood intake during pregnancy was conducted. We found an inverse dose-response association between dietary intake of dioxins and PCBs and fetal growth after adjustment for confounders. Newborns of mothers in the upper quartile of dioxin and dioxin-like PCBs intake had 62g lower birth weight (95% CI: -73, -50), 0.26cm shorter birth length (95% CI: -0.31, -0.20) and 0.10cm shorter head circumference (95% CI: -0.14, -0.06) than newborns of mothers in the lowest quartile of intake. Similar negative associations for intake of dioxins and dioxin-like PCBs were found after excluding women with intakes above the tolerable weekly intake (TWI=14pg TEQ/kg bw/week). The negative association of dietary dioxins and PCBs with fetal growth was weaker as seafood intake was increasing. No association was found between dietary dioxin and PCB intake and the risk for small-for-gestational age neonate. In conclusion, dietary intakes of dioxins and PCBs during pregnancy were negatively associated with fetal growth, even at intakes below the TWI. © 2013.

AN ASSESSMENT OF DIOXIN LEVELS IN PROCESSED ...

Science.gov (United States)

The presence of dioxin-like compounds in ball clay was discovered in 1996 as a result of an investigation to determine the sources of elevated levels of dioxin found in two chicken fat samples from a national survey of poultry. The investigation indicated that soybean meal added to chicken feed was the source of dioxin contamination. Further investigation showed that the dioxin contamination came from the mixing of a natural clay known as

Impact of perinatal dioxin exposure on infant growth: a cross-sectional and longitudinal studies in dioxin-contaminated areas in Vietnam.

Science.gov (United States)

Nishijo, Muneko; Tai, Pham The; Nakagawa, Hideaki; Maruzeni, Shoko; Anh, Nguyen Thi Nguyet; Luong, Hoang Van; Anh, Tran Hai; Honda, Ryumon; Morikawa, Yuko; Kido, Teruhiko; Nishijo, Hisao

2012-01-01

Dioxin exposure levels remain elevated in residents living around former US Air Force bases in Vietnam, indicating potential adverse impacts on infant growth. In this study, 210 mother-infant pairs in dioxin-contaminated areas in Vietnam were recruited at the infants' birth and followed up for 4 months. Perinatal dioxin exposure levels were estimated by measurement of polychlorinated dibenzo-p-dioxins/furans toxic equivalent (PCDDs/Fs-TEQ) in breast milk. The infants' size was measured at birth and 1 and 4 months after birth, and neurodevelopment was evaluated using the Bayley Scales III at 4 months of age. Among 4 dioxin groups (language, and fine motor scores in the ≥75 percentile group were significantly lower than those in the other groups. These results suggested a considerable impact of perinatal dioxin exposure on infant growth, particularly in boys exposed to dioxins at high level of PCDDs/Fs-TEQ.

Possible additional exposure to dioxin and dioxin-like compounds from waste incineration. Biomonitoring using human milk and animal samples

Energy Technology Data Exchange (ETDEWEB)

Sampaio, C.; M. Fatima Reis; J. Pereira Miguel [Inst. of Preventive Medicine, Univ. of Lisbon (Portugal); Murk, A. [Wageningen Univ., Dept. of Toxicology (Netherlands)

2004-09-15

In the ambit of an Environmental Health Survey Program relative to a MSW facility, which has been operating near to Lisbon since 1999 a biomonitoring study using human breast milk has been performed. Specific aims of this study were: (1) determine whether living in the vicinity of the incinerator increases dioxin maternal body burden and accordingly perinatal (intra-uterus and lactacional) exposure; (2) to investigate the possibility of increased human exposure to dioxins and dioxin-like compounds via locally produced food items from animal origin. Therefore, levels of dioxins and dioxin-like compounds have been determined in human milk samples collected in the vicinity of the incinerator and in a control area, for comparison. From the same areas, cow and sheep milk and eggs from free-range chickens have also been collected to get an indication of possible local additional exposure to air-borne dioxins via the food chain. Analyses of TCDD-equivalents (TEQs) were mainly performed with a reporter gene assay for dioxin-like activity, the DR-CALUX bioassay (Dioxin Responsive Chemical Activated LUciferase gene eXpression).To determine congeners profile, some human milk samples have also been analysed for PCDD/Fs and relevant dioxin-like PCBs, by using high-resolution gas chromatography and high-resolution mass spectrometry (HRGC/HRMS). Both the Ethics Committees of the Faculty of Medicine, University of Lisbon, and of the Maternity Dr. Alfredo da Costa have approved the study protocol.

Imprinted genes and transpositions: epigenomic targets for low dose radiation effects. Final report

International Nuclear Information System (INIS)

Jirtle, Randy L.

2012-01-01

The overall hypothesis of this grant application is that low dose ionizing radiation (LDIR) elicits adaptive responses in part by causing heritable DNA methylation changes in the epigenome. This novel postulate was tested by determining if the level of DNA methylation at the Agouti viable yellow (A vy ) metastable locus is altered, in a dose-dependent manner, by low dose radiation exposure ( vy locus in a sex-specific manner (p=0.004). Average DNA methylation was significantly increased in male offspring exposed to doses between 0.7 cGy and 7.6 cGy with maximum effects at 1.4 cGy and 3.0 cGy (p<0.01). Offspring coat color was concomitantly shifted towards pseudoagouti (p<0.01). Maternal dietary antioxidant supplementation mitigated both the DNA methylation changes and coat color shift in the irradiated offspring (p<0.05). Thus, LDIR exposure during gestation elicits epigenetic alterations that lead to positive adaptive phenotypic changes that are negated with antioxidants, indicating they are mediated in part by oxidative stress. These findings provide evidence that in the isogenic Avy mouse model epigenetic alterations resulting from LDIR play a role in radiation hormesis, bringing into question the assumption that every dose of radiation is harmful. Our findings not only have significant implications concerning the mechanism of hormesis, but they also emphasize the potential importance of this phenomenon in determining human risk at low radiation doses. Since the epigenetic regulation of genes varies markedly between species, the effect of LDIR on other epigenetically labile genes (e.g. imprinted genes) in animals and humans needs to be defined

Cancer risk of low dose/low dose rate radiation: a meta-analysis of cancer data of mammals exposed to low doses of radiation

International Nuclear Information System (INIS)

Ogata, Hiromitsu; Magae, Junji

2008-01-01

Full text: Linear No Threshold (LNT) model is a basic theory for radioprotection, but the adaptability of this hypothesis to biological responses at low doses or at low dose rates is not sufficiently investigated. Simultaneous consideration of the cumulative dose and the dose rate is necessary for evaluating the risk of long-term exposure to ionizing radiation at low dose. This study intends to examine several numerical relationships between doses and dose rates in biological responses to gamma radiation. Collected datasets on the relationship between dose and the incidence of cancer in mammals exposed to low doses of radiation were analysed using meta-regression models and modified exponential (MOE) model, which we previously published, that predicts irradiation time-dependent biological response at low dose rate ionizing radiation. Minimum doses of observable risk and effective doses with a variety of dose rates were calculated using parameters estimated by fitting meta-regression models to the data and compared them with other statistical models that find values corresponding to 'threshold limits'. By fitting a weighted regression model (fixed-effects meta-regression model) to the data on risk of all cancers, it was found that the log relative risk [log(RR)] increased as the total exposure dose increased. The intersection of this regression line with the x-axis denotes the minimum dose of observable risk. These estimated minimum doses and effective doses increased with decrease of dose rate. The goodness of fits of MOE-model depended on cancer types, but the total cancer risk is reduced when dose rates are very low. The results suggest that dose response curve for cancer risk is remarkably affected by dose rate and that dose rate effect changes as a function of dose rate. For scientific discussion on the low dose exposure risk and its uncertainty, the term 'threshold' should be statistically defined, and dose rate effects should be included in the risk

Data integration reveals key homeostatic mechanisms following low dose radiation exposure

Energy Technology Data Exchange (ETDEWEB)

Tilton, Susan C.; Matzke, Melissa M. [Computational Biology and Bioinformatics, Pacific Northwest National Laboratory, Richland, WA 99338 (United States); Sowa, Marianne B.; Stenoien, David L.; Weber, Thomas J. [Health Impacts and Exposure Science, Pacific Northwest National Laboratory, Richland, WA 99338 (United States); Morgan, William F. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99338 (United States); Waters, Katrina M., E-mail: katrina.waters@pnnl.gov [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99338 (United States)

2015-05-15

The goal of this study was to define pathways regulated by low dose radiation to understand how biological systems respond to subtle perturbations in their environment and prioritize pathways for human health assessment. Using an in vitro 3-D human full thickness skin model, we have examined the temporal response of dermal and epidermal layers to 10 cGy X-ray using transcriptomic, proteomic, phosphoproteomic and metabolomic platforms. Bioinformatics analysis of each dataset independently revealed potential signaling mechanisms affected by low dose radiation, and integrating data shed additional insight into the mechanisms regulating low dose responses in human tissue. We examined direct interactions among datasets (top down approach) and defined several hubs as significant regulators, including transcription factors (YY1, MYC and CREB1), kinases (CDK2, PLK1) and a protease (MMP2). These data indicate a shift in response across time — with an increase in DNA repair, tissue remodeling and repression of cell proliferation acutely (24–72 h). Pathway-based integration (bottom up approach) identified common molecular and pathway responses to low dose radiation, including oxidative stress, nitric oxide signaling and transcriptional regulation through the SP1 factor that would not have been identified by the individual data sets. Significant regulation of key downstream metabolites of nitrative stress was measured within these pathways. Among the features identified in our study, the regulation of MMP2 and SP1 was experimentally validated. Our results demonstrate the advantage of data integration to broadly define the pathways and networks that represent the mechanisms by which complex biological systems respond to perturbation. - Highlights: • Low dose ionizing radiation altered homeostasis in 3D skin tissue model. • Global gene/protein/metabolite data integrated using complementary statistical approaches • Time and location-specific change in matrix regulation

Identification of Differential Gene Expression Patterns after Acute Exposure to High and Low Doses of Low-LET Ionizing Radiation in a Reconstituted Human Skin Tissue

Energy Technology Data Exchange (ETDEWEB)

Tilton, Susan C.; Markillie, Lye Meng; Hays, Spencer; Taylor, Ronald C.; Stenoien, David L.

2016-11-01

Our goal here was to identify dose and temporal dependent radiation responses in a complex tissue, reconstituted human skin. Direct sequencing of RNA (RNA-seq) was used to quantify altered transcripts following exposure to 0.1, 2 and 10 Gy of ionizing radiation at 3 and 8 hours. These doses include a low dose in the range of some medical diagnostic procedures (0.1 Gy), a dose typically received during radiotherapy (2.0 Gy) and a lethal dose (10 Gy). These doses could be received after an intentional or accidental radiation exposure and biomarkers are needed to rapidly and accurately triage exposed individuals. A total of 1701 genes were deemed to be significantly affected by high dose radiation exposure with the majority of genes affected at 10 Gy. A group of 29 genes including GDF15, BBC3, PPM1D, FDXR, GADD45A, MDM2, CDKN1A, TP53INP1, CYCSP27, SESN1, SESN2, PCNA, and AEN were similarly altered at both 2 and 10 Gy, but not 0.1 Gy, at multiple time points. A much larger group of up regulated genes, including those involved in inflammatory responses, was significantly altered only after a 10 Gy exposure. At high doses, down regulated genes were associated with cell cycle regulation and exhibited an apparent linear response between 2 and 10 Gy. While only a handful of genes were significantly affected by 0.1 Gy exposure using stringent statistical filters, groups of related genes regulating cell cycle progression and inflammatory responses consistently exhibited opposite trends in their regulation compared to the high dose exposures. Differential regulation of PLK1 signaling at low and high doses was confirmed using qRT-PCR. These results indicate that some alterations in gene expression are qualitatively different at low and high doses of radiation in this model system.

Association of dioxins, furans and dioxin-like PCBs in human blood with nephropathy among US teens and young adults.

Science.gov (United States)

Everett, Charles J; Thompson, Olivia M

2016-06-01

We assessed the association of three chlorinated dibenzo-p-dioxins, a chlorinated dibenzofuran, and four dioxin-like polychlorinated biphenyls (PCBs) in human blood with nephropathy (microalbuminuria or macroalbuminuria) among teens and young adults (12-30 years old) having normal glycohemoglobin (A1c Dioxins, furans and dioxin-like PCBs in human blood: causes or consequences of diabetic nephropathy? Environ Res 2014;132:126-31), the cut-offs for these chemicals being considered elevated, were defined as the 75th percentile. Using these same cut-offs again, the proportion of those with one or more of the eight dioxin-like compounds elevated was 9.9%. The four chemicals associated with nephropathy were 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin, PCB 126, PCB 169, and PCB 156. The proportion with one or more of these four dioxin-like chemicals elevated was 3.9% (unweighted n=46) and the odds ratio (OR) for nephropathy was 7.1 [95% confidence interval (CI) 1.8-28.1]. The association was strong among females (OR 17.4, 95% CI 3.4-88.6), but among males there were no cases of nephropathy when one or more of the four dioxin-like chemicals were elevated, and therefore no association. In a separate analysis, elevated toxic equivalency, defined using the eight dioxin-like chemicals (TEQ8), was associated with nephropathy. TEQ8 ≥50.12 fg/g included 2.6% of the sample (unweighted n=28) and had an OR of 5.8 (95% 1.3-25.9) for nephropathy. As found in the analysis of one or more of four dioxin-like chemicals elevated, TEQ8 ≥50.12 fg/g was associated with nephropathy among females (OR 11.9, 95% CI 1.6-87.2), but not males. Trends for least-squares means also differed by gender, but there were no significant differences in mean TEQ8 between normal subjects and those having nephropathy in either males or females. We also evaluated pre-diabetes (A1c 5.7-6.4%) without nephropathy and found no associations when one or more of four dioxin-like compounds were elevated, or when TEQ8 was

PCB 126 and Other Dioxin-Like PCBs Specifically Suppress Hepatic PEPCK Expression via the Aryl Hydrocarbon Receptor

Science.gov (United States)

Zhang, Wenshuo; Sargis, Robert M.; Volden, Paul A.; Carmean, Christopher M.; Sun, Xiao J.; Brady, Matthew J.

2012-01-01

Dioxins and dioxin-like compounds encompass a group of structurally related heterocyclic compounds that bind to and activate the aryl hydrocarbon receptor (AhR). The prototypical dioxin is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a highly toxic industrial byproduct that incites numerous adverse physiological effects. Global commercial production of the structurally similar polychlorinated biphenyls (PCBs), however, commenced early in the 20th century and continued for decades; dioxin-like PCBs therefore contribute significantly to total dioxin-associated toxicity. In this study, PCB 126, the most potent dioxin-like PCB, was evaluated with respect to its direct effects on hepatic glucose metabolism using primary mouse hepatocytes. Overnight treatment with PCB 126 reduced hepatic glycogen stores in a dose-dependent manner. Additionally, PCB 126 suppressed forskolin-stimulated gluconeogenesis from lactate. These effects were independent of acute toxicity, as PCB 126 did not increase lactate dehydrogenase release nor affect lipid metabolism or total intracellular ATP. Interestingly, provision of cells with glycerol instead of lactate as the carbon source completely restored hepatic glucose production, indicating specific impairment in the distal arm of gluconeogenesis. In concordance with this finding, PCB 126 blunted the forskolin-stimulated increase in phosphoenolpyruvate carboxykinase (PEPCK) mRNA levels without affecting glucose-6-phosphatase expression. Myricetin, a putative competitive AhR antagonist, reversed the suppression of PEPCK induction by PCB 126. Furthermore, other dioxin-like PCBs demonstrated similar effects on PEPCK expression in parallel with their ability to activate AhR. It therefore appears that AhR activation mediates the suppression of PEPCK expression by dioxin-like PCBs, suggesting a role for these pollutants as disruptors of energy metabolism. PMID:22615911

PCB 126 and other dioxin-like PCBs specifically suppress hepatic PEPCK expression via the aryl hydrocarbon receptor.

Directory of Open Access Journals (Sweden)

Wenshuo Zhang

Full Text Available Dioxins and dioxin-like compounds encompass a group of structurally related heterocyclic compounds that bind to and activate the aryl hydrocarbon receptor (AhR. The prototypical dioxin is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, a highly toxic industrial byproduct that incites numerous adverse physiological effects. Global commercial production of the structurally similar polychlorinated biphenyls (PCBs, however, commenced early in the 20(th century and continued for decades; dioxin-like PCBs therefore contribute significantly to total dioxin-associated toxicity. In this study, PCB 126, the most potent dioxin-like PCB, was evaluated with respect to its direct effects on hepatic glucose metabolism using primary mouse hepatocytes. Overnight treatment with PCB 126 reduced hepatic glycogen stores in a dose-dependent manner. Additionally, PCB 126 suppressed forskolin-stimulated gluconeogenesis from lactate. These effects were independent of acute toxicity, as PCB 126 did not increase lactate dehydrogenase release nor affect lipid metabolism or total intracellular ATP. Interestingly, provision of cells with glycerol instead of lactate as the carbon source completely restored hepatic glucose production, indicating specific impairment in the distal arm of gluconeogenesis. In concordance with this finding, PCB 126 blunted the forskolin-stimulated increase in phosphoenolpyruvate carboxykinase (PEPCK mRNA levels without affecting glucose-6-phosphatase expression. Myricetin, a putative competitive AhR antagonist, reversed the suppression of PEPCK induction by PCB 126. Furthermore, other dioxin-like PCBs demonstrated similar effects on PEPCK expression in parallel with their ability to activate AhR. It therefore appears that AhR activation mediates the suppression of PEPCK expression by dioxin-like PCBs, suggesting a role for these pollutants as disruptors of energy metabolism.

Maternal diet, prenatal exposure to dioxin-like compounds and birth outcomes in a European prospective mother-child study (NewGeneris).

Science.gov (United States)

Papadopoulou, Eleni; Kogevinas, Manolis; Botsivali, Maria; Pedersen, Marie; Besselink, Harrie; Mendez, Michelle A; Fleming, Sarah; Hardie, Laura J; Knudsen, Lisbeth E; Wright, John; Agramunt, Silvia; Sunyer, Jordi; Granum, Berit; Gutzkow, Kristine B; Brunborg, Gunnar; Alexander, Jan; Meltzer, Helle Margrete; Brantsæter, Anne Lise; Sarri, Katerina; Chatzi, Leda; Merlo, Domenico F; Kleinjans, Jos C; Haugen, Margaretha

2014-06-15

Maternal diet can result in exposure to environmental contaminants including dioxins which may influence foetal growth. We investigated the association between maternal diet and birth outcomes by defining a dioxin-rich diet. We used validated food frequency questionnaires to assess the diet of pregnant women from Greece, Spain, United Kingdom, Denmark and Norway and estimated plasma dioxin-like activity by the Dioxin-Responsive Chemically Activated LUciferase eXpression (DR-CALUX®) bioassay in 604 maternal blood samples collected at delivery. We applied reduced rank regression to identify a dioxin-rich dietary pattern based on dioxin-like activity (DR-CALUX®) levels in maternal plasma, and calculated a dioxin-diet score as an estimate of adherence to this dietary pattern. In the five country population, dioxin-diet score was characterised by high consumption of red and white meat, lean and fatty fish, low-fat dairy and low consumption of salty snacks and high-fat cheese, during pregnancy. The upper tertile of the dioxin-diet score was associated with a change in birth weight of -121g (95% confidence intervals: -232, -10g) compared to the lower tertile after adjustment for confounders. A small non-significant reduction in gestational age was also observed (-1.4days, 95% CI: -3.8, 1.0days). Our results suggest that maternal diet might contribute to the exposure of the foetus to dioxins and dioxin-like compounds and may be related to reduced birth weight. More studies are needed to develop updated dietary guidelines for women of reproductive age, aiming to the reduction of dietary exposure to persistent organic pollutants as dioxins and dioxin-like compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

Dioxins and polyvinylchloride in combustion and fires.

Science.gov (United States)

Zhang, Mengmei; Buekens, Alfons; Jiang, Xuguang; Li, Xiaodong

2015-07-01

This review on polyvinylchloride (PVC) and dioxins collects, collates, and compares data from selected sources on the formation of polychlorinated dibenzofurans (PCDFs) and dibenzo-p-dioxins (PCDDs), or in brief dioxins, in combustion and fires. In professional spheres, the incineration of PVC as part of municipal solid waste is seldom seen as a problem, since deep flue gas cleaning is required anyhow. Conversely, with its high content of chlorine, PVC is frequently branded as a major chlorine donor and spitefully leads to substantial formation of dioxins during poorly controlled or uncontrolled combustion and open fires. Numerous still ill-documented and diverse factors of influence may affect the formation of dioxins during combustion: on the one hand PVC-compounds represent an array of materials with widely different formulations; on the other hand these may all be exposed to fires of different nature and consequences. Hence, attention should be paid to PVC with respect to the ignition and development of fires, as well as attenuating the emission of objectionable compounds, such as carbon monoxide, hydrogen chloride, polycyclic aromatic hydrocarbons, and dioxins. This review summarises available dioxin emissions data, gathers experimental and simulation studies of fires and combustion tests involving PVC, and identifies and analyses the effects of several local factors of influence, affecting the formation of dioxins during PVC combustion. © The Author(s) 2015.

Radiolytic treatment of dioxin contaminated soils

International Nuclear Information System (INIS)

Gray, K.A.; Hilarides, R.J.

1995-01-01

Recent work in our laboratory has demonstrated that γ-radiolysis is a feasible method by which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can be converted to products of negligible toxicity. In the presence of 25% water, 2.5% non-ionic surfactant and at a dose of 800 kGy greater than 98% destruction was achieved in a standard soil artificially contaminated with 100 ppb TCDD. By-product analysis has illustrated that the destruction occurs via step-wise reductive dechlorination producing a suite of lesser chlorinated dioxins. These results in combination with scavenger studies, target theory calculations and yields indicate that direct radiation effects account for the major route of destruction. Radiolysis has also been conducted on a real soil contaminated with TCDD and other chlorinated aromatic compounds verifying the results of model studies. Based on the data of these experiments some designs of batch gamma systems are considered and a discussion of estimated capital and operating costs associated with γ-radiolysis is presented. Given the high costs of the alternatives (i.e. incineration), radiolysis appears to be not only technically feasible, but it may also be economically competitive. (author)

Health risk assessment of exposure to dioxin-like PCBs and dioxins in the City of Menen (Belgium)

Energy Technology Data Exchange (ETDEWEB)

Nouwen, J.; Provoost, J.; Cornelis, C.; Bronders, J.; Fre, R. de; Clauvenbergern, R. van [Flemish Insitute for Technological Research (Vito) (Belgium)

2004-09-15

The City of Menen is a well-outlined residential area located in the neighbourhood of two waste incinerators. The waste incinerators (Menen (Belgium) and Roncq (France)) are in full operation since the eighties. Emission measurements indicate that they fulfil the European Union dioxin emission standard of 0.1 ng TEQ/m{sup 3}. Despite this, new deposition measurements and analysis of milk in this region indicate a high burden of the local environment with dioxin-like polychlorinated biphenyls (dioxin-like PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). It should be noted that formerly the City of Menen was also surrounded by other potential dioxin sources, among them a dye factory, some small illegal cable burning houses, a pressed board manufacturer, and a metal recycling plant. Before 1984, fly ashes of the waste incinerator were locally used as road materials and transported. This could be a secondary source. Additionally the Environmental Inspection has regularly noticed some large open waste fires in this region and follows up the situation. On request of the Public Waste Agency of Flanders (OVAM) an inventory of all dioxin measurements within the city area was made. The ratio of the dioxin-like PCBs compared to the PCDD/Fs in these measurement results was unexpectedly high. As a consequence of this and in order to achieve an optimal risk assessment for the people living in the City of Menen an additional sampling of soil, vegetables and eggs was carried out. This article focuses on the relative amounts of dioxin-like PCBs and PCDD/Fs in the different media and the consequences for the outcome of the risk assessment.

Human exposure to dioxin from combustion sources

International Nuclear Information System (INIS)

Hattemer-Frey, H.A.; Travis, C.C.

1988-01-01

Because of their extreme toxicity, much concern and debate has arisen about the nature and extent of human exposure to dioxin. Since municipal solid waste (MSW) incinerators are known to emit polychorinated dibenzo-p-dioxins (PCDDs) and polycholorinated dibenzofurnas (PCDFs) many people who live near MSW incinerators fear that they will be exposed to high levels of dioxin and subsequently develop cancer. What is often overlooked in this debate, however, is the fact that the general population is continuously being exposed to trace amounts of dioxin as exemplified by the fact that virtually all human adipose tissue samples contain dioxin at levels of 3 parts per trillion (ppt) or greater. This paper provides a perspective on MSW incineration as a source of human exposure to dioxin by comparing this exposure source with exposure to background environmental contamination and evaluates some of the potential key sources of PCDD/PCDF input into the enviroment. 32 refs., 3 tabs

Dioxins, dibenzofurans, dioxin-like PCBs, and DDE in U.S. fast food, 1995.

Science.gov (United States)

Schecter, A; Li, L

1997-01-01

Food, especially dairy products, meat, and fish, is the primary source of environmental exposure to dioxins in the general population. Little data exists on dioxin levels in the popular and widely consumed "fast foods". Data presented in a previously published pilot study was limited to measuring only the levels of dioxins and dibenzofurans in three types of U.S. fast food. This study adds to the previous paper by presenting data, in addition to dioxins and dibenzofurans, on the closely related dioxin-like polychlorinated biphenyls (PCBs), and the persistent metabolite of DDT, 1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene (DDE), in four types of popular U.S. fast food. These include McDonald's Big Mac Hamburger, Pizza Hut's Personal Pan Pizza Supreme, Kentucky Fried Chicken (KFC) three piece original recipe mixed dark and white meat luncheon package, and Häagen-Daz chocolate-chocolate chip ice cream. Dioxin plus dibenzofuran dioxin toxic equivalents (TEQ) ranged from 0.03 to 0.28 TEQ pg/g wet or whole weight for the Big Mac, from 0.03 to 0.29 for the Pizza, from 0.01 to 0.31 for the KFC, and from 0.03 to 0.49 TEQ pg/g for the ice cream. Daily TEQ consumption per kilogram body weight (kg/BW), assuming an average 65 kg adult and a 20 kg child, from one serving of each of these fast food ranged between 0.046 and 1.556 pg/kg in adults whereas in children the values were between 0.15 and 5.05 pg/kg. Total measured PCDD/Fs in the Big Mac, Personal Pan Pizza, KFC, and the Häagen-Daz ice cream varied from 0.58 to 9.31 pg/g. Measured DDE levels in the fast foods ranged from 180 to 3170 pg/g. Total mono-ortho PCB levels ranged up to 500 pg/g or 1.28 TEQ pg/g for the KFC and for di-ortho PCBs up to 740 pg/g or 0.014 TEQ pg/g for the pizza sample. Total PCB values in the four samples ranged up to 1170 pg/g or 1.29 TEQ pg/g for the chicken sample.

Characteristic vibrational frequencies of toxic polychlorinated dibenzo-dioxins and -furans

International Nuclear Information System (INIS)

Patrizi, Barbara; Cumis, Mario Siciliani de; Viciani, Silvia; D’Amato, Francesco; Foggi, Paolo

2014-01-01

Highlights: • Database reporting FT-IR spectra for 13 of the 17 toxic PCDDs and PCDFs congeners. • Use of FT-IR database for quantification of toxic PCDD/Fs in complex matrix. • Monitoring of dioxin emissions from waste incinerators. - Abstract: The possibility to monitor in real-time the emission of dioxins produced by incineration of waste or by industrial processes is nowadays a necessity considering the high toxicity of these compounds, their persistence in the environment and their ability to bio-accumulate in the food chain. Recently it has been demonstrated the potentiality of detecting dioxins in carbon tetrachloride via MIR Quantum Cascade Lasers. A fundamental step in real time monitoring of dioxins emission is the possibility to recognize the most toxic congeners within complex mixtures and at low concentrations. Taking into account the lack of spectroscopic data about these very toxic environmental pollutants and the necessity to monitor their emissions we have recorded infrared spectra of 13 of the 17 most toxic congeners of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzo-furans (PCDFs) dissolved in carbon tetrachloride. In this way we have obtained a small database that we have used to test the ability of a linear regression algorithm to recognize each congener and its relative concentration in complex mixtures of these compounds

Characteristic vibrational frequencies of toxic polychlorinated dibenzo-dioxins and -furans

Energy Technology Data Exchange (ETDEWEB)

Patrizi, Barbara, E-mail: patrizi@lens.unifi.it [LENS, University of Florence, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); CNR, Istituto Nazionale di Ottica, Largo Enrico Fermi 6, 50125 Firenze (Italy); Cumis, Mario Siciliani de; Viciani, Silvia; D’Amato, Francesco [CNR, Istituto Nazionale di Ottica, Largo Enrico Fermi 6, 50125 Firenze (Italy); Foggi, Paolo [LENS, University of Florence, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); CNR, Istituto Nazionale di Ottica, Largo Enrico Fermi 6, 50125 Firenze (Italy); Università degli Studi di Perugia, Dipartimento di Chimica, Via Elce di Sotto 8, 06123 Perugia (Italy)

2014-06-01

Highlights: • Database reporting FT-IR spectra for 13 of the 17 toxic PCDDs and PCDFs congeners. • Use of FT-IR database for quantification of toxic PCDD/Fs in complex matrix. • Monitoring of dioxin emissions from waste incinerators. - Abstract: The possibility to monitor in real-time the emission of dioxins produced by incineration of waste or by industrial processes is nowadays a necessity considering the high toxicity of these compounds, their persistence in the environment and their ability to bio-accumulate in the food chain. Recently it has been demonstrated the potentiality of detecting dioxins in carbon tetrachloride via MIR Quantum Cascade Lasers. A fundamental step in real time monitoring of dioxins emission is the possibility to recognize the most toxic congeners within complex mixtures and at low concentrations. Taking into account the lack of spectroscopic data about these very toxic environmental pollutants and the necessity to monitor their emissions we have recorded infrared spectra of 13 of the 17 most toxic congeners of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzo-furans (PCDFs) dissolved in carbon tetrachloride. In this way we have obtained a small database that we have used to test the ability of a linear regression algorithm to recognize each congener and its relative concentration in complex mixtures of these compounds.

Feasibility, system design, and economic evaluation of radiolytic degradation of 2,3,7,8-tetrachlorodibenzo-p-dioxin on soil

International Nuclear Information System (INIS)

Hilarides, R.J.; Gray, K.A.; Guzzetta, J.; Cortellucci, N.; Sommer, C.

1996-01-01

This research shows that gamma irradiation is both a technically and economically feasible method to degrade chlorinated dioxins on soil. Approximately 99% degradation of dioxin on a model soil was achieved using gamma radiation at a dose of 800 kGy. In addition, this research determined the initial pathway of destruction, identified several controlling parameters, and developed a mass balance on degradation. The general applicability of this model behavior was successfully tested in a native contaminated soil where nearly 75% of the dioxin was destroyed at a dose of 450 kGy. Through a theoretical and conceptual understanding of radiolysis in soil, a sound basis for engineering design was established. Gamma radiation sources are commercially available, and this research outlines a new application of an established technology. A number of irradiator designs are proposed, and preliminary economic estimates are made to demonstrate that radiolysis can be a real alternative to incineration. (author)

Low doses effects

International Nuclear Information System (INIS)

Tubiana, M.

1997-01-01

In this article is asked the question about a possible carcinogens effect of low dose irradiation. With epidemiological data, knowledge about the carcinogenesis, the professor Tubiana explains that in spite of experiments made on thousand or hundred of thousands animals it has not been possible to bring to the fore a carcinogens effect for low doses and then it is not reasonable to believe and let the population believe that low dose irradiation could lead to an increase of neoplasms and from this point of view any hardening of radiation protection standards could in fact, increase anguish about ionizing radiations. (N.C.)

New insights to the role of aryl hydrocarbon receptor in bone phenotype and in dioxin-induced modulation of bone microarchitecture and material properties

International Nuclear Information System (INIS)

Herlin, Maria; Finnilä, Mikko A.J.; Zioupos, Peter; Aula, Antti; Risteli, Juha; Miettinen, Hanna M.; Jämsä, Timo; Tuukkanen, Juha; Korkalainen, Merja; Håkansson, Helen; Viluksela, Matti

2013-01-01

Bone is a target for high affinity aryl hydrocarbon receptor (AHR) ligands, such as dioxins. Although bone morphology, mineral density and strength are sensitive endpoints of dioxin toxicity, less is known about effects on bone microarchitecture and material properties. This study characterizes TCDD-induced modulations of bone tissue, and the role of AHR in dioxin-induced bone toxicity and for normal bone phenotype. Six AHR-knockout (Ahr −/− ) and wild-type (Ahr +/+ ) mice of both genders were exposed to TCDD weekly for 10 weeks, at a total dose of 200 μg/kg bw. Bones were examined with micro-computed tomography, nanoindentation and biomechanical testing. Serum levels of bone remodeling markers were analyzed, and the expression of genes related to osteogenic differentiation was profiled using PCR array. In Ahr +/+ mice, TCDD-exposure resulted in harder bone matrix, thinner and more porous cortical bone, and a more compact trabecular bone compartment. Bone remodeling markers and altered expression of a number of osteogenesis related genes indicated imbalanced bone remodeling. Untreated Ahr −/− mice displayed a slightly modified bone phenotype as compared with untreated Ahr +/+ mice, while TCDD exposure caused only a few changes in bones of Ahr −/− mice. Part of the effects of both TCDD-exposure and AHR-deficiency were gender dependent. In conclusion, exposure of adult mice to TCDD resulted in harder bone matrix, thinner cortical bone, mechanically weaker bones and most notably, increased trabecular bone volume fraction in Ahr +/+ mice. AHR is involved in bone development of a normal bone phenotype, and is crucial for manifestation of TCDD-induced bone alterations. - Highlights: • TCDD disrupts bone remodeling resulting in altered cortical and trabecular bone. • In trabecular bone an anabolic effect is observed. • Cortical bone is thinner, more porous, harder, stiffer and mechanically weaker. • AHR ablation results in increased trabecular bone

New insights to the role of aryl hydrocarbon receptor in bone phenotype and in dioxin-induced modulation of bone microarchitecture and material properties

Energy Technology Data Exchange (ETDEWEB)

Herlin, Maria, E-mail: maria.herlin@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Finnilä, Mikko A.J., E-mail: mikko.finnila@oulu.fi [Department of Medical Technology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Zioupos, Peter, E-mail: p.zioupos@cranfield.ac.uk [Biomechanics Laboratories, Department of Engineering and Applied Science, Cranfield University, Shrivenham SN6 8LA (United Kingdom); Aula, Antti, E-mail: antti.aula@gmail.com [Department of Medical Physics, Imaging Centre, Tampere University Hospital, Tampere (Finland); Department of Biomedical Engineering, Tampere University of Technology, Tampere (Finland); Risteli, Juha, E-mail: juha.risteli@ppshp.fi [Department of Clinical Chemistry, Oulu University Hospital, Oulu (Finland); Miettinen, Hanna M., E-mail: hanna.miettinen@crl.com [Department of Environmental Health, National Institute for Health and Welfare, Kuopio (Finland); Jämsä, Timo, E-mail: timo.jamsa@oulu.fi [Department of Medical Technology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Department of Diagnostic Radiology, Oulu University Hospital, Oulu (Finland); Tuukkanen, Juha, E-mail: juha.tuukkanen@oulu.fi [Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Korkalainen, Merja, E-mail: merja.korkalainen@thl.fi [Department of Environmental Health, National Institute for Health and Welfare, Kuopio (Finland); Håkansson, Helen, E-mail: Helen.Hakansson@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Viluksela, Matti, E-mail: matti.viluksela@thl.fi [Department of Environmental Health, National Institute for Health and Welfare, Kuopio (Finland); Department of Environmental Science, University of Eastern Finland, Kuopio (Finland)

2013-11-15

Bone is a target for high affinity aryl hydrocarbon receptor (AHR) ligands, such as dioxins. Although bone morphology, mineral density and strength are sensitive endpoints of dioxin toxicity, less is known about effects on bone microarchitecture and material properties. This study characterizes TCDD-induced modulations of bone tissue, and the role of AHR in dioxin-induced bone toxicity and for normal bone phenotype. Six AHR-knockout (Ahr{sup −/−}) and wild-type (Ahr{sup +/+}) mice of both genders were exposed to TCDD weekly for 10 weeks, at a total dose of 200 μg/kg bw. Bones were examined with micro-computed tomography, nanoindentation and biomechanical testing. Serum levels of bone remodeling markers were analyzed, and the expression of genes related to osteogenic differentiation was profiled using PCR array. In Ahr{sup +/+} mice, TCDD-exposure resulted in harder bone matrix, thinner and more porous cortical bone, and a more compact trabecular bone compartment. Bone remodeling markers and altered expression of a number of osteogenesis related genes indicated imbalanced bone remodeling. Untreated Ahr{sup −/−} mice displayed a slightly modified bone phenotype as compared with untreated Ahr{sup +/+} mice, while TCDD exposure caused only a few changes in bones of Ahr{sup −/−} mice. Part of the effects of both TCDD-exposure and AHR-deficiency were gender dependent. In conclusion, exposure of adult mice to TCDD resulted in harder bone matrix, thinner cortical bone, mechanically weaker bones and most notably, increased trabecular bone volume fraction in Ahr{sup +/+} mice. AHR is involved in bone development of a normal bone phenotype, and is crucial for manifestation of TCDD-induced bone alterations. - Highlights: • TCDD disrupts bone remodeling resulting in altered cortical and trabecular bone. • In trabecular bone an anabolic effect is observed. • Cortical bone is thinner, more porous, harder, stiffer and mechanically weaker. • AHR ablation

Sorption, mobility, and fate of 1,4,7,8-tetrachlorodibenzo-p-dioxin in soils

Energy Technology Data Exchange (ETDEWEB)

Larsen, G.; Hakk, H. [USDA ARS Biosciences Research Lab., Fargo (United States); Fan, Z.; Casey, F. [North Dakota State Univ., Fargo (United States)

2004-09-15

Most dioxins are released into the environment through low temperature combustion processes, which include waste incineration and metal refining. Incineration of medical and municipal wastes in the early 1990s was estimated to generate 0.7g -5 kg dioxin Toxic Equivalents (TEQ)/yr and 2-3 kg TEQ/yr of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs) emissions, respectively. Governmental regulatory controls on waste incinerators have resulted in an annual decrease of dioxins/furans emissions from 13.5 kg TEQ/yr to 2.8 kg TEQ/yr from 1987 to 1995. Recently backyard burning of household waste has been shown to produce more PCDDs/PCDFs per mass burned than a typical modern municipal waste incinerator and has been estimated to account for 22% of the dioxin emissions in North America from 1996-1997. These combustion processes result in direct deposition of dioxins on soil. While degradation studies of PCDDs/PCDFs have been conducted on contaminated soils, little is known about the sorption, transport, and fate of dioxins in various soil types. 1,4,7,8- Tetrachlorodibenzo-p-dioxin (1478-TCDD) was also found to be a significant congener of the dioxins in ball clay.7 Ball clay had been used as an anti-caking agent in soybean meal of animal feed but its use has subsequently been discontinued. The main goal of this study was to identify the fate and transport of 1478-TCDD in various soils and sand through the use of laboratory batch and soil column experiments.

Exposure to Low-Dose X-Ray Radiation Alters Bone Progenitor Cells and Bone Microarchitecture.

Science.gov (United States)

Lima, Florence; Swift, Joshua M; Greene, Elisabeth S; Allen, Matthew R; Cunningham, David A; Braby, Leslie A; Bloomfield, Susan A

2017-10-01

Exposure to high-dose ionizing radiation during medical treatment exerts well-documented deleterious effects on bone health, reducing bone density and contributing to bone growth retardation in young patients and spontaneous fracture in postmenopausal women. However, the majority of human radiation exposures occur in a much lower dose range than that used in the radiation oncology clinic. Furthermore, very few studies have examined the effects of low-dose ionizing radiation on bone integrity and results have been inconsistent. In this study, mice were irradiated with a total-body dose of 0.17, 0.5 or 1 Gy to quantify the early (day 3 postirradiation) and delayed (day 21 postirradiation) effects of radiation on bone microarchitecture and bone marrow stromal cells (BMSCs). Female BALBc mice (4 months old) were divided into four groups: irradiated (0.17, 0.5 and 1 Gy) and sham-irradiated controls (0 Gy). Micro-computed tomography analysis of distal femur trabecular bone from animals at day 21 after exposure to 1 Gy of X-ray radiation revealed a 21% smaller bone volume (BV/TV), 22% decrease in trabecular numbers (Tb.N) and 9% greater trabecular separation (Tb.Sp) compared to sham-irradiated controls (P X-rays, whereas osteoclastogenesis was enhanced. A better understanding of the effects of radiation on osteoprogenitor cell populations could lead to more effective therapeutic interventions that protect bone integrity for individuals exposed to low-dose ionizing radiation.

Dioxin contamination in the soil. South of Vietnam

Energy Technology Data Exchange (ETDEWEB)

Mai, Tuan Anh; Tarradellas, J.; DeAlancastro, F.; Grandjean, D. [CECOTOX-ISTE-ENAC-EPFL, Lausanne (Switzerland); Doan, Thanh Vu; Huynh, Thi Minh Hang [National Univ. of Hochiminh City, Inst. for Environment and Resources (Viet Nam)

2004-09-15

Dioxin is a common name given to a group of persistent and very toxic chemicals, also known as dioxins and furans. These chemicals include 75 chlorinated dibenzo-p-dioxins and 135 chlorinated dibenzo furans. The most toxic of these compounds is 2,3,7,8-tetrachlorodibenzo-p-dioxin and the isomers with chlorines substituted in the 2,3,7,8 positions. Dioxin in the environment is measured and reported in terms of 2,3,7,8-TCDD equivalents, which are the actual concentrations of each dioxin or furan congener multiplied by its relative toxicity. The amount of dioxin in a sample is the sum of the concentration of 2,3,7,8-TCDD and 2,3,7,8-TCDD-equivalents. The problem of dioxin contamination in South of Vietnam has been reported in many documents as a typical case because there are many areas affected by the toxic chemicals from US-Vietnam War. Although the War ended in 1975, to date no large-scale epidemiological study has been performed to assess the effects of the herbicides used on the Vietnamese people and ecosystem. Nowadays, the study on this problem is relatively difficult because many times passed (over 28 years) and every thing has been changed (not in origin form): a grand part of dioxin had been degraded or transfered into biological food web. In addition, the document collection and sampling planning are not easy work due to the complete formalities or military secrets. In this paper we present our primary result on dioxin contamination of three selected areas, including: Ma Da Forest, Cam Lo District - Quang Tri Province and Da Nang Airport. These are also the common names that reported in the documents related to the dioxin contamination problem.

Biological effects of low doses of radiation at low dose rate

International Nuclear Information System (INIS)

1996-05-01

The purpose of this report was to examine available scientific data and models relevant to the hypothesis that induction of genetic changes and cancers by low doses of ionizing radiation at low dose rate is a stochastic process with no threshold or apparent threshold. Assessment of the effects of higher doses of radiation is based on a wealth of data from both humans and other organisms. 234 refs., 26 figs., 14 tabs

Low doses of six toxicants change plant size distribution in dense populations of Lactuca sativa.

Science.gov (United States)

Belz, Regina G; Patama, Marjo; Sinkkonen, Aki

2018-08-01

Toxicants are known to have negligible or stimulatory, i.e. hormetic, effects at low doses below those that decrease the mean response of a plant population. Our earlier observations indicated that at such low toxicant doses the growth of very fast- and slow-growing seedlings is selectively altered, even if the population mean remains constant. Currently, it is not known how common these selective low-dose effects are, whether they are similar among fast- and slow-growing seedlings, and whether they occur concurrently with hormetic effects. We tested the response of Lactuca sativa in complete dose-response experiments to six different toxicants at doses that did not decrease population mean and beyond. The tested toxicants were IAA, parthenin, HHCB, 4-tert-octylphenol, glyphosate, and pelargonic acid. Each experiment consisted of 14,400-16,800 seedlings, 12-14 concentrations, 24 replicates per concentration and 50 germinated seeds per replicate. We analyzed the commonness of selective low-dose effects and explored if toxic effects and hormetic stimulation among fast- and slow-growing individuals occurred at the same concentrations as they occur at the population level. Irrespective of the observed response pattern and toxicant, selective low-dose effects were found. Toxin effects among fast-growing individuals usually started at higher doses compared to the population mean, while the opposite was found among slow-growing individuals. Very low toxin exposures tended to homogenize plant populations due to selective effects, while higher, but still hormetic doses tended to heterogenize plant populations. Although the extent of observed size segregation varied with the specific toxin tested, we conclude that a dose-dependent alteration in size distribution of a plant population may generally apply for many toxin exposures. Copyright © 2018 Elsevier B.V. All rights reserved.

LOW COST SOLIDIFICATION/STABILIZATION TREATMENT FOR SOILS CONTAMINATED WITH DIOXIN, PCP AND CREOSOTE

Science.gov (United States)

The USEPA's NRMRL conducted successful treatability tests of innovative solidification/stabilization (S/S) formulations to treat soils contaminated with dioxins, pentachlorophenol (PCP), and creosote from four wood preserving sites. Formulations developed during these studies wer...

Dioxin body burden among blood donors before and after the Belgian dioxin/PCB incident

Energy Technology Data Exchange (ETDEWEB)

Debacker, N.; Sasse, A.; Wouwe, N. Van; Windal, I.; Carbonnelle, S.; Overmeire, I. Van; Sartor, F.; Goeyens, L.; Oyen, H. Van [Scientific Inst. of Public Health, Brussels (Belgium); Eppe, G.; Xhrouet, C.; Pauw, E. De [Centre of Analysis of Residues in Traces, Luik (Belgium)

2004-09-15

In spring 1999, Belgium faced a severe food contamination when about 50 kg of PCBs containing 1 g of dioxins were introduced in the food chain. The possible public health impact of this food chain contamination was subject of a debate between different scientists. According to Vrijens et al. and Bernard et al. there was no significant public health impact, whereas van Larebeke et al. presumed the opposite claiming a significant increase of cancer incidence. These risk assessments were based on measurements of dioxins/PCBs in contaminated foods and nutritional habits observed in a selected group of adolescents (14-18 years old) using simulation techniques or on the estimation of the incremental cancer risk associated with the incremental levels of exposure to dioxins/PCBs during the incident. In the meantime, an epidemiological survey has been carried out in order to measure the dioxin levels in plasma samples collected before and after the incident. The aim of this paper is to report the preliminary results of this epidemiological survey.

Triple quadrupole tandem mass spectrometry: A real alternative to high resolution magnetic sector instrument for the analysis of polychlorinated dibenzo-p-dioxins, furans and dioxin-like polychlorinated biphenyls.

Science.gov (United States)

García-Bermejo, Ángel; Ábalos, Manuela; Sauló, Jordi; Abad, Esteban; González, María José; Gómara, Belén

2015-08-19

This paper reports on the optimisation, characterisation, validation and applicability of gas chromatography coupled to triple quadrupole mass spectrometry in its tandem operation mode (GC-QqQ(MS/MS) for the quantification of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs, dioxins) and dioxin-like polychlorinated biphenyls (DL-PCBs) in environmental and food matrices. MS/MS parameters were selected to achieve the high sensitivity and selectivity required for the analysis of this type of compounds and samples. Good repeatability for areas (RSD = 1-10%, for PCDD/Fs and DL-PCBs) and for ion transition ratios (RSD = 0.3-10%, for PCDD/Fs, and 0.2-15%, for DL-PCBs) and low instrumental limits of detection, 0.07-0.75 pg μL(-1) (for dioxins) and 0.05-0.63 pg μL(-1) (for DL-PCBs), were obtained. A comparative study of the congener specific determination using both GC-QqQ(MS/MS) and gas chromatography-high resolution mass spectrometry (GC-HRMS) was also performed by analysing several fortified samples and certified reference materials (CRMs) with low (feed and foodstuffs), median (sewage sludge) and high (fly ash) toxic equivalency (TEQ) concentration levels, i.e. 0.60, 1.83, 72.9 and 3609 pg WHO-TEQ(PCDD/Fs) g(-1). The agreement between the results obtained for the total TEQs (dioxins) on GC-QqQ(MS/MS) and GC-HRMS in all the investigated samples were within the range of ±4%, and that of DL-PCBs at concentration levels of 0.84 pg WHO-TEQs (DL-PCBs) g(-1), in the case of feedstuffs, was 0.11%. Both instrumental methods have similar and comparable linearity, precision and accuracy. The GC-QqQ(MS/MS) sensitivity, lower than that of GC-HRMS, is good enough (iLODs in the down to low pg levels) to detect the normal concentrations of these compounds in food and environmental samples. These results make GC-QqQ(MS/MS) suitable for the quantitative analysis of dioxins and DL-PCBs and a real alternative tool to the reference sector HRMS instruments. Copyright © 2015 Elsevier

Decomposition of dioxin analogues and ablation study for carbon nanotube

International Nuclear Information System (INIS)

Yamauchi, Toshihiko

2002-01-01

Two application studies associated with the free electron laser are presented separately, which are the titles of 'Decomposition of Dioxin Analogues' and 'Ablation Study for Carbon Nanotube'. The decomposition of dioxin analogues by infrared (IR) laser irradiation includes the thermal destruction and multiple-photon dissociation. It is important for us to choose the highly absorbable laser wavelength for the decomposition. The thermal decomposition takes place by the irradiation of the low IR laser power. Considering the model of thermal decomposition, it is proposed that adjacent water molecules assist the decomposition of dioxin analogues in addition to the thermal decomposition by the direct laser absorption. The laser ablation study is performed for the aim of a carbon nanotube synthesis. The vapor by the ablation is weakly ionized in the power of several-hundred megawatts. The plasma internal energy is kept over an 8.5 times longer than the vacuum. The cluster was produced from the weakly ionized gas in the enclosed gas, which is composed of the rough particles in the low power laser more than the high power which is composed of the fine particles. (J.P.N.)

Rapid methods for dioxin and dioxin-like PCBs in food and feedingstuffs. State of the art

Energy Technology Data Exchange (ETDEWEB)

Behnisch, P.A. [eurofins-GfA, Muenster (Germany); Hoogenboom, R. [RIKILT-Institute of Food Safety, Wageningen (Netherlands)

2004-09-15

The increasing number of local dioxin crises since 2002 becoming more and more apparent due to stricter controls of feed and food in the European Union and the globally increasing number of countries applying similar guidelines make it necessary to establish reliable, time and cost-effective screening methods for the dioxin intake through nutritional pathways. Five years after the last overview presentation about all kinds of different bio-analytical detection methods (BDMs) and the establishment of quality guidelines for screening methods, time has come to include as well the improvements in the chemical methods to speed up the analysis. This review gives an overview about the state-of-the-art improvements and gives a future outlook for both methods, chemical and bio-analytical approach for rapid analyses of dioxins and dioxin-like compounds. Now several new ways of improvement are currently in the pipeline of research and testing, such as PCR, proteomic biomarkers and in case of the clean-up ASE11, PowerPrep and different detection methods as well as different other ways of indicators for dioxins (e.g. correlations to fatty acids).

Dioxins in processes of incineration of wastes

International Nuclear Information System (INIS)

Perez John; Espinel Jorge; Ocampo Alonso; Londono Carlos

2001-01-01

This paper is a door to come into the subject of dioxins, which is a little bit known in Colombia. In this way, in order to clarify and to get a wider knowledge about dioxins and waste incineration process, it has been divided in three main sections. The first one gives a basic information about origin, effects on the human health and a chemical definition of dioxins; in the second one the main kind of incinerator processes are given to know, also a deeper knowledge of reaction formation. The last part emphasizes options to control dioxins emissions in incineration systems

Dioxin formation and control in a gasification-melting plant.

Science.gov (United States)

Kawamoto, Katsuya; Miyata, Haruo

2015-10-01

We investigated dioxin formation and removal in a commercial thermal waste treatment plant employing a gasification and melting process that has become widespread in the last decade in Japan. The aim was to clarify the possibility of dioxin formation in a process operation at high temperatures and the applicability of catalytic decomposition of dioxins. Also, the possible use of dioxin surrogate compounds for plant monitoring was further evaluated. The main test parameter was the influence of changes in the amount and type of municipal solid waste (MSW) supplied to the thermal waste treatment plant which from day to day operation is a relevant parameter also from commercial perspective. Here especially, the plastic content on dioxin release was assessed. The following conclusions were reached: (1) disturbance of combustion by adding plastic waste above the capability of the system resulted in a considerable increase in dioxin content of the flue gas at the inlet of the bag house and (2) bag filter equipment incorporating a catalytic filter effectively reduced the gaseous dioxin content below the standard of 0.1 ng toxic equivalency (TEQ)/m(3) N, by decomposition and partly adsorption, as was revealed by total dioxin mass balance and an increased levels in the fly ash. Also, the possible use of organohalogen compounds as dioxin surrogate compounds for plant monitoring was further evaluated. The levels of these surrogates did not exceed values corresponding to 0.1 ng TEQ/m(3) N dioxins established from former tests. This further substantiated that surrogate measurement therefore can well reflect dioxin levels.

Levels of dioxins and dioxin-like PCBs in food of animal origin in the Netherlands during the period 2001-2011.

Science.gov (United States)

Adamse, Paulien; Schoss, Stefanie; Theelen, Rob M C; Hoogenboom, Ron L A P

2017-01-01

The aim of this study was to assess levels of dioxins (polychlorinated dibenzo-p-dioxins and dibenzofurans, PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs) (DL-PCBs) in food of animal origin produced in the Netherlands, including potential trends in time. Test results from about 2500 samples of animal derived food products (beef, veal, lamb, chicken, pork, deer, milk and eggs), sampled for the National Residue Monitoring Plan from 2001-2011, were evaluated. Most samples were screened with a bioassay and, if suspected, analysed by GC-HRMS. The fraction of samples which were non-compliant with European maximum levels was rather low, being below 1% for most food products, except for lamb. Exceedance of action levels was particularly observed for lamb and beef. To obtain an insight into background levels, a randomly taken part of the samples was directly analysed by GC-HRMS. In general, only minor decreases in mean PCDD/F and DL-PCB concentrations could be observed for the period 2001-2011. This may be due to a plateauing of current background levels but also to factors like the sensitivity of the analytical method.

Low dose irradiation reduces cancer mortality rates

International Nuclear Information System (INIS)

Luckey, T.D.

2000-01-01

Low doses of ionizing radiation stimulate development, growth, memory, sensual acuity, fecundity, and immunity (Luckey, T.D., ''Radiation Hormesis'', CRC Press, 1991). Increased immune competence reduces cancer mortality rates and provides increased average lifespan in animals. Decreased cancer mortality rates in atom bomb victims who received low dose irradiation makes it desirable to examine populations exposed to low dose irradiation. Studies with over 300,000 workers and 7 million person-years provide a valid comparison of radiation exposed and control unclear workers (Luckey, T.D., Nurture with Ionizing Radiation, Nutrition and Cancer, 34:1-11, 1999). Careful selection of controls eliminated any ''healthy worker effect''. The person-year corrected average indicated the cancer mortality rate of exposed workers was only 51% that of control workers. Lung cancer mortality rates showed a highly significant negative correlation with radon concentrations in 272,000 U.S. homes (Cohen, B.L., Health Physics 68:157-174, 1995). In contrast, radon concentrations showed no effect on lung cancer rates in miners from different countries (Lubin, J.H. Am. J. Epidemiology 140:323-332, 1994). This provides evidence that excessive lung cancer in miners is caused by particulates (the major factor) or toxic gases. The relative risk for cancer mortality was 3.7% in 10,000 Taiwanese exposed to low level of radiation from 60 Co in their steel supported homes (Luan, Y.C. et al., Am. Nuclear Soc. Trans. Boston, 1999). This remarkable finding needs further study. A major mechanism for reduced cancer mortality rates is increased immune competence; this includes both cell and humoral components. Low dose irradiation increases circulating lymphocytes. Macrophage and ''natural killer'' cells can destroy altered (cancer) cells before the mass becomes too large. Low dose irradiation also kills suppressor T-cells; this allows helper T-cells to activate killer cells and antibody producing cells

Effect of low dose electron beam irradiation on the alteration layer formed during nuclear glass leaching

Energy Technology Data Exchange (ETDEWEB)

Mougnaud, S., E-mail: sarah.mougnaud@gmail.com [CEA Marcoule, DEN, DTCD, SECM, BP 17171, 30207 Bagnols-sur-Cèze cedex (France); Tribet, M. [CEA Marcoule, DEN, DTCD, SECM, BP 17171, 30207 Bagnols-sur-Cèze cedex (France); Renault, J.-P. [NIMBE, CNRS, CEA, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette cedex (France); Jollivet, P. [CEA Marcoule, DEN, DTCD, SECM, BP 17171, 30207 Bagnols-sur-Cèze cedex (France); Panczer, G. [Institut Lumière Matière, UMR 5306, Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne cedex (France); Charpentier, T. [NIMBE, CNRS, CEA, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette cedex (France); Jégou, C. [CEA Marcoule, DEN, DTCD, SECM, BP 17171, 30207 Bagnols-sur-Cèze cedex (France)

2016-12-15

This investigation concerns borosilicate glass leaching mechanisms and the evolution of alteration layer under electron beam irradiation. A simple glass doped with rare earth elements was selected in order to access mechanistic and structural information and better evaluate the effects of irradiation. It was fully leached in initially pure water at 90 °C and at high glass surface area to solution volume ratio (S/V = 20 000 m{sup −1}) in static conditions. Under these conditions, the system quickly reaches the residual alteration rate regime. A small particle size fraction (2–5 μm) was sampled in order to obtain a fairly homogeneous altered material enabling the use of bulk characterization methods. External irradiations with 10 MeV electrons up to a dose of 10 MGy were performed either before or after leaching, to investigate respectively the effect of initial glass irradiation on its alteration behavior and the irradiation stability of the alteration layer. Glass dissolution rate was analyzed by regular leachate samplings and the alteration layer structure was characterized by Raman, luminescence (continuous or time-resolved), and {sup 29}Si MAS NMR and EPR spectroscopy. It was shown that the small initial glass evolutions under irradiation did not induce any modification of the leaching kinetic nor of the structure of the alteration layer. The alteration process seemed to “smooth over” the created defects. Otherwise, the alteration layer and initial glass appeared to have different behaviors under irradiation. No Eu{sup 3+} reduction was detected in the alteration layer after irradiation and the defect creation efficiency was much lower than for initial glass. This can possibly be explained by the protective role of pore water contained in the altered material (∼20%). Moreover, a slight depolymerization of the silicon network of the altered glass under irradiation with electrons was evidenced, whereas in the initial glass it typically

Citizen participatory dioxin monitoring campaign by pine needles as biomonitor of ambient air dioxin pollution

Energy Technology Data Exchange (ETDEWEB)

Komichi, I.; Takatori, A. [Environmental Research Institute Inc., Tokyo (Japan); Aoyama, T. [Musashi Institute of Technology, Yokohama (Japan). Faculty of Environment and Informations; Vrzic, B. [Maxxam Analytics Inc. HRMS Laboratory, Waterloo, ON (Canada)

2004-09-15

The needle-type leaves of Japanese black pine trees (hereafter abbreviated as pine needles) have been used as an effective bio-monitor of ambient air pollution. Miyata Laboratory of Setsunan University has reported that the pine needles accumulate PCDDs and PCDFs (hereafter abbreviated as D/F) through photosynthesis and respiration during their lifetime. On the basis of this study, we have revealed the correlation between ambient air and pine needle concentrations to be estimated at or near 1:10 by analyzing long term continuous ambient dioxin monitoring data and that of pine needles sampled from the same area as ambient air in the Kanagawa Prefecture in 1999. Since then, the citizen groups of each local area all over Japan have started monitoring the ambient air dioxin concentration levels by using pine needles. Samples analyzed during these 5 years totaled more than 650 throughout Japan. The results of these citizen participatory environmental monitoring activities are the tremendous effects achieved in reducing the dioxin levels. This occurs through observation of the dioxin emission sources such as Municipal Solid Waste Incineration Plants as well as the Industrial Waste Incineration plants, which exist in numbers exceeding several thousands in Japan. This short paper will present the results of 56 municipalities of western Japan where ambient air dioxin levels have improved steadily against local averages during these 5 years.

Michigan dioxin exposure study: planning phase and protocol development

Energy Technology Data Exchange (ETDEWEB)

Adriaens, P. [Univ. of Michigan, Coll. of Engineering, Ann Arbor (United States); Garabrant, D.; Franzblau, A. [Univ. of Michigan, School for Public Health, Ann Arbor (United States); Gillespie, B. [Univ. of Michigan, Center for Statistics, Ann Arbor (United States); Lepowski, J. [Univ. of Michigan, Inst. for Social Research, Ann Arbor (United States)

2004-09-15

The University of Michigan has been commissioned to conduct one of the largest environmental epidemiology studies (700 residents) of dioxin exposure among the population of Michigan to describe the pattern of serum dioxin levels among adults and to understand the factors that explain variation in serum dioxin levels. The study is being undertaken (2004-2006) in response to concerns among the population of Midland and Saginaw Counties that dioxins from the Dow Chemical Company facilities in Midland have resulted in contamination of areas of the City of Midland and have contaminated the sediments in the Tittabawassee River flood plain. There is concern that body burdens of dioxins are elevated because of environmental contamination. The appropriate way to respond to these concerns is to measure the serum dioxin levels in a probability sample of the population in the region and to estimate each individual's past exposure to various factors that are believed to contribute to the body burden of dioxins. By measuring factors that reflect potential exposure to dioxins through air, water, soil, food intake, occupations, and various recreational activities, we can identify the factors that correlate with (and explain variation in) serum dioxin levels. The central goal of the study is to determine which factors explain variation in serum dioxin levels, and to quantify how much variation each factor explains. This paper provides information on the planning phase, study scope and objectives.

Pediatric Obesity: Pharmacokinetic Alterations and Effects on Antimicrobial Dosing.

Science.gov (United States)

Natale, Stephanie; Bradley, John; Nguyen, William Huy; Tran, Tri; Ny, Pamela; La, Kirsten; Vivian, Eva; Le, Jennifer

2017-03-01

Limited data exist for appropriate drug dosing in obese children. This comprehensive review summarizes pharmacokinetic (PK) alterations that occur with age and obesity, and these effects on antimicrobial dosing. A thorough comparison of different measures of body weight and specific antimicrobial agents including cefazolin, cefepime, ceftazidime, daptomycin, doripenem, gentamicin, linezolid, meropenem, piperacillin-tazobactam, tobramycin, vancomycin, and voriconazole is presented. PubMed (1966-July 2015) and Cochrane Library searches were performed using these key terms: children, pharmacokinetic, obesity, overweight, body mass index, ideal body weight, lean body weight, body composition, and specific antimicrobial drugs. PK studies in obese children and, if necessary, data from adult studies were summarized. Knowledge of PK alterations stemming from physiologic changes that occur with age from the neonate to adolescent, as well as those that result from increased body fat, become an essential first step toward optimizing drug dosing in obese children. Excessive amounts of adipose tissue contribute significantly to body size, total body water content, and organ size and function that may modify drug distribution and clearance. PK studies that evaluated antimicrobial dosing primarily used total (or actual) body weight (TBW) for loading doses and TBW or adjusted body weight for maintenance doses, depending on the drugs' properties and dosing units. PK studies in obese children are imperative to elucidate drug distribution, clearance, and, consequently, the dose required for effective therapy in these children. Future studies should evaluate the effects of both age and obesity on drug dosing because the incidence of obesity is increasing in pediatric patients. © 2017 Pharmacotherapy Publications, Inc.

Dioxin exerts anti-estrogenic actions in a novel dioxin-responsive telomerase-immortalized epithelial cell line of the porcine oviduct (TERT-OPEC).

Science.gov (United States)

Hombach-Klonisch, Sabine; Pocar, Paola; Kauffold, Johannes; Klonisch, Thomas

2006-04-01

Oviduct epithelial cells are important for the nourishment and survival of ovulated oocytes and early embryos, and they respond to the steroid hormones estrogen and progesterone. Endocrine-disrupting polyhalogenated aromatic hydrocarbons (PHAH) are environmental toxins that act in part through the ligand-activated transcription factor arylhydrocarbon receptor (AhR; dioxin receptor), and exposure to PHAH has been shown to decrease fertility. To investigate effects of PHAHs on the oviduct epithelium as a potential target tissue of dioxin-type endocrine disruptors, we have established a novel telomerase-immortalized oviduct porcine epithelial cell line (TERT-OPEC). TERT-OPEC exhibited active telomerase and the immunoreactive epithelial marker cytokeratin but lacked the stromal marker vimentin. TERT-OPEC contained functional estrogen receptor (ER)-alpha and AhR, as determined by the detection of ER-alpha- and AhR-specific target molecules. Treatment of TERT-OPEC with the AhR ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) resulted in a significant increase in the production of the cytochrome P-450 microsomal enzyme CYP1A1. Activated AhR caused a downregulation of ER nuclear protein fraction and significantly decreased ER-signaling in TERT-OPEC as determined by ERE-luciferase transient transfection assays. In summary, the TCDD-induced and AhR-mediated anti-estrogenic responses by TERT-OPEC suggest that PHAH affect the predominantly estrogen-dependent differentiation of the oviduct epithelium within the fallopian tube. This action then alters the local endocrine milieu, potentially resulting in a largely unexplored cause of impaired embryonic development and female infertility.

Effect of low dose radiation on apoptosis in mouse spleen

International Nuclear Information System (INIS)

Chen Dong; Liu Jiamei; Chen Aijun; Liu Shuzheng

1999-01-01

Objective: To study the effect of whole body irradiation (WBI) with different doses of X-ray on apoptosis in mouse spleen. Methods: Time course changes and dose-effect relationship of apoptosis in mouse spleen induced by WBI were observed with transmission electron microscopy (TEM) qualitatively and TUNEL method semi-quantitatively. Results: Many typical apoptotic lymphocytes were found by TEM in mouse spleen after WBI with 2 Gy. No marked alterations of ultrastructure were found following WBI with 0.075 Gy. It was observed by TUNEL that the apoptosis of splenocytes increased after high dose radiation and decreased following low dose radiation (LDR). The dose-effect relationship of radiation-induced apoptosis showed a J-shaped curve. Conclusion: The effect of different doses of ionizing radiation on apoptosis in mouse spleen was distinct. And the decrease of apoptosis after LDR is considered a manifestation of radiation hormesis

Advanced Computational Approaches for Characterizing Stochastic Cellular Responses to Low Dose, Low Dose Rate Exposures

Energy Technology Data Exchange (ETDEWEB)

Scott, Bobby, R., Ph.D.

2003-06-27

OAK - B135 This project final report summarizes modeling research conducted in the U.S. Department of Energy (DOE), Low Dose Radiation Research Program at the Lovelace Respiratory Research Institute from October 1998 through June 2003. The modeling research described involves critically evaluating the validity of the linear nonthreshold (LNT) risk model as it relates to stochastic effects induced in cells by low doses of ionizing radiation and genotoxic chemicals. The LNT model plays a central role in low-dose risk assessment for humans. With the LNT model, any radiation (or genotoxic chemical) exposure is assumed to increase one¡¯s risk of cancer. Based on the LNT model, others have predicted tens of thousands of cancer deaths related to environmental exposure to radioactive material from nuclear accidents (e.g., Chernobyl) and fallout from nuclear weapons testing. Our research has focused on developing biologically based models that explain the shape of dose-response curves for low-dose radiation and genotoxic chemical-induced stochastic effects in cells. Understanding the shape of the dose-response curve for radiation and genotoxic chemical-induced stochastic effects in cells helps to better understand the shape of the dose-response curve for cancer induction in humans. We have used a modeling approach that facilitated model revisions over time, allowing for timely incorporation of new knowledge gained related to the biological basis for low-dose-induced stochastic effects in cells. Both deleterious (e.g., genomic instability, mutations, and neoplastic transformation) and protective (e.g., DNA repair and apoptosis) effects have been included in our modeling. Our most advanced model, NEOTRANS2, involves differing levels of genomic instability. Persistent genomic instability is presumed to be associated with nonspecific, nonlethal mutations and to increase both the risk for neoplastic transformation and for cancer occurrence. Our research results, based on

Dioxin induces genomic instability in mouse embryonic fibroblasts.

Directory of Open Access Journals (Sweden)

Merja Korkalainen

Full Text Available Ionizing radiation and certain other exposures have been shown to induce genomic instability (GI, i.e., delayed genetic damage observed many cell generations later in the progeny of the exposed cells. The aim of this study was to investigate induction of GI by a nongenotoxic carcinogen, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD. Mouse embryonic fibroblasts (C3H10T1/2 were exposed to 1, 10 or 100 nM TCDD for 2 days. Micronuclei (MN and expression of selected cancer-related genes were assayed both immediately and at a delayed point in time (8 days. For comparison, similar experiments were done with cadmium, a known genotoxic agent. TCDD treatment induced an elevated frequency of MN at 8 days, but not directly after the exposure. TCDD-induced alterations in gene expression were also mostly delayed, with more changes observed at 8 days than at 2 days. Exposure to cadmium produced an opposite pattern of responses, with pronounced effects immediately after exposure but no increase in MN and few gene expression changes at 8 days. Although all responses to TCDD alone were delayed, menadione-induced DNA damage (measured by the Comet assay, was found to be increased directly after a 2-day TCDD exposure, indicating that the stability of the genome was compromised already at this time point. The results suggested a flat dose-response relationship consistent with dose-response data reported for radiation-induced GI. These findings indicate that TCDD, although not directly genotoxic, induces GI, which is associated with impaired DNA damage response.

Relationship between dioxin concentration and particle size for suspended sediment

Energy Technology Data Exchange (ETDEWEB)

Kitamura, K.; Sakurai, T.; Choi, J.W.; Suzuki, N.; Morita, M. [National Inst. for Environmental Studies, Tsukuba (Japan)

2004-09-15

The purpose of the present study was to find out how the amounts of adsorbed dioxins, i.e., polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/Fs), mono-ortho-polychlorinated biphenyls (PCBs) and non-ortho-PCBs, vary with the particle size of suspended sediment. As dioxins are hydrophobic, they tend to adsorb onto particles suspended in water, and the determination of which dioxin congeners readily dissolve in water or adsorb onto particles is central to the characterization of dioxin behavior in water/sediment systems. Presumably suspension of sediments and the size of the particles govern the transfer of dioxins to aquatic organisms. Therefore, in the present study, we investigated the relationship between the amount of dioxins and the particle-size distribution of resuspended, rather than settled, sediment.

Multivariate Analysis and Prediction of Dioxin-Furan ...

Science.gov (United States)

Peer Review Draft of Regional Methods Initiative Final Report Dioxins, which are bioaccumulative and environmentally persistent, pose an ongoing risk to human and ecosystem health. Fish constitute a significant source of dioxin exposure for humans and fish-eating wildlife. Current dioxin analytical methods are costly, time-consuming, and produce hazardous by-products. A Danish team developed a novel, multivariate statistical methodology based on the covariance of dioxin-furan congener Toxic Equivalences (TEQs) and fatty acid methyl esters (FAMEs) and applied it to North Atlantic Ocean fishmeal samples. The goal of the current study was to attempt to extend this Danish methodology to 77 whole and composite fish samples from three trophic groups: predator (whole largemouth bass), benthic (whole flathead and channel catfish) and forage fish (composite bluegill, pumpkinseed and green sunfish) from two dioxin contaminated rivers (Pocatalico R. and Kanawha R.) in West Virginia, USA. Multivariate statistical analyses, including, Principal Components Analysis (PCA), Hierarchical Clustering, and Partial Least Squares Regression (PLS), were used to assess the relationship between the FAMEs and TEQs in these dioxin contaminated freshwater fish from the Kanawha and Pocatalico Rivers. These three multivariate statistical methods all confirm that the pattern of Fatty Acid Methyl Esters (FAMEs) in these freshwater fish covaries with and is predictive of the WHO TE

2,3,7,8-Tetrachlorodibenzo-p-dioxin activates the aryl hydrocarbon receptor and alters sex steroid hormone secretion without affecting growth of mouse antral follicles in vitro

Energy Technology Data Exchange (ETDEWEB)

Karman, Bethany N., E-mail: bklement@illinois.edu; Basavarajappa, Mallikarjuna S., E-mail: mbshivapur@gmail.com; Craig, Zelieann R., E-mail: zelieann@illinois.edu; Flaws, Jodi A., E-mail: jflaws@illinois.edu

2012-05-15

The persistent environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is an ovarian toxicant. These studies were designed to characterize the actions of TCDD on steroidogenesis and growth of intact mouse antral follicles in vitro. Specifically, these studies tested the hypothesis that TCDD exposure leads to decreased sex hormone production/secretion by antral follicles as well as decreased growth of antral follicles in vitro. Since TCDD acts through binding to the aryl hydrocarbon receptor (AHR), and the AHR has been identified as an important factor in ovarian function, we also conducted experiments to confirm the presence and activation of the AHR in our tissue culture system. To do so, we exposed mouse antral follicles for 96 h to a series of TCDD doses previously shown to have effects on ovarian tissues and cells in culture, which also encompass environmentally relevant and pharmacological exposures (0.1–100 nM), to determine a dose response for TCDD in our culture system for growth, hormone production, and expression of the Ahr and Cyp1b1. The results indicate that TCDD decreases progesterone, androstenedione, testosterone, and estradiol levels in a non-monotonic dose response manner without altering growth of antral follicles. The addition of pregnenolone substrate (10 μM) restores hormone levels to control levels. Additionally, Cyp1b1 levels were increased by 3–4 fold regardless of the dose of TCDD exposure, evidence of AHR activation. Overall, these data indicate that TCDD may act prior to pregnenolone formation and through AHR transcriptional control of Cyp1b1, leading to decreased hormone levels without affecting growth of antral follicles. -- Highlights: ►TCDD disrupts sex steroid hormone levels, but not growth of antral follicles. ►Pregnenolone co-treatment by-passes TCDD-induced steroid hormone disruption. ►TCDD affects steroid hormone levels through an AHR pathway in antral follicles.

Imprinted genes and transpositions: epigenomic targets for low dose radiation effects. Final report

Energy Technology Data Exchange (ETDEWEB)

Jirtle, Randy L.

2012-10-11

The overall hypothesis of this grant application is that low dose ionizing radiation (LDIR) elicits adaptive responses in part by causing heritable DNA methylation changes in the epigenome. This novel postulate was tested by determining if the level of DNA methylation at the Agouti viable yellow (A{sup vy}) metastable locus is altered, in a dose-dependent manner, by low dose radiation exposure (<10 cGy) during early gestation. This information is particularly important to ascertain given the increased use of CT scans in disease diagnosis, increased number of people predicted to live and work in space, and the present concern about radiological terrorism. We showed for the first time that LDIR significantly increased DNA methylation at the A{sup vy} locus in a sex-specific manner (p=0.004). Average DNA methylation was significantly increased in male offspring exposed to doses between 0.7 cGy and 7.6 cGy with maximum effects at 1.4 cGy and 3.0 cGy (p<0.01). Offspring coat color was concomitantly shifted towards pseudoagouti (p<0.01). Maternal dietary antioxidant supplementation mitigated both the DNA methylation changes and coat color shift in the irradiated offspring (p<0.05). Thus, LDIR exposure during gestation elicits epigenetic alterations that lead to positive adaptive phenotypic changes that are negated with antioxidants, indicating they are mediated in part by oxidative stress. These findings provide evidence that in the isogenic Avy mouse model epigenetic alterations resulting from LDIR play a role in radiation hormesis, bringing into question the assumption that every dose of radiation is harmful. Our findings not only have significant implications concerning the mechanism of hormesis, but they also emphasize the potential importance of this phenomenon in determining human risk at low radiation doses. Since the epigenetic regulation of genes varies markedly between species, the effect of LDIR on other epigenetically labile genes (e.g. imprinted genes) in

Dioxins levels in Australia. Key findings of studies

Energy Technology Data Exchange (ETDEWEB)

Ivory, A.; Mobbs, C. [Australian Government Department of the Environment and Heritage (Australia)

2004-09-15

The Australian Government established the National Dioxins Program (NDP) in 2001 to improve knowledge about levels of dioxins in Australia. The program aims to determine levels, assess the risks to Australians and the environment, and to consider appropriate management actions. Starting in mid 2001and completed in 2004, the studies constituted the largest survey of dioxin levels ever undertaken in Australia. The findings will contribute to debate on how to deal with dioxins in Australia, as well as helping to meet obligations under the Stockholm Convention on Persistent Organic Pollutants, which Australia ratified on 20 May 2004. These studies will also contribute to a better understanding about dioxins in the southern hemisphere. This paper provides a summary of the key findings of these studies and the risk assessments.

Third-generation Ah receptor-responsive luciferase reporter plasmids: amplification of dioxin-responsive elements dramatically increases CALUX bioassay sensitivity and responsiveness.

Science.gov (United States)

He, Guochun; Tsutsumi, Tomoaki; Zhao, Bin; Baston, David S; Zhao, Jing; Heath-Pagliuso, Sharon; Denison, Michael S

2011-10-01

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, dioxin) and related dioxin-like chemicals are widespread and persistent environmental contaminants that produce diverse toxic and biological effects through their ability to bind to and activate the Ah receptor (AhR) and AhR-dependent gene expression. The chemically activated luciferase expression (CALUX) system is an AhR-responsive recombinant luciferase reporter gene-based cell bioassay that has been used in combination with chemical extraction and cleanup methods for the relatively rapid and inexpensive detection and relative quantitation of dioxin and dioxin-like chemicals in a wide variety of sample matrices. Although the CALUX bioassay has been validated and used extensively for screening purposes, it has some limitations when screening samples with very low levels of dioxin-like chemicals or when there is only a small amount of sample matrix for analysis. Here, we describe the development of third-generation (G3) CALUX plasmids with increased numbers of dioxin-responsive elements, and stable transfection of these new plasmids into mouse hepatoma (Hepa1c1c7) cells has produced novel amplified G3 CALUX cell bioassays that respond to TCDD with a dramatically increased magnitude of luciferase induction and significantly lower minimal detection limit than existing CALUX-type cell lines. The new G3 CALUX cell lines provide a highly responsive and sensitive bioassay system for the detection and relative quantitation of very low levels of dioxin-like chemicals in sample extracts.

Third-Generation Ah Receptor–Responsive Luciferase Reporter Plasmids: Amplification of Dioxin-Responsive Elements Dramatically Increases CALUX Bioassay Sensitivity and Responsiveness

Science.gov (United States)

He, Guochun; Tsutsumi, Tomoaki; Zhao, Bin; Baston, David S.; Zhao, Jing; Heath-Pagliuso, Sharon; Denison, Michael S.

2011-01-01

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, dioxin) and related dioxin-like chemicals are widespread and persistent environmental contaminants that produce diverse toxic and biological effects through their ability to bind to and activate the Ah receptor (AhR) and AhR-dependent gene expression. The chemically activated luciferase expression (CALUX) system is an AhR-responsive recombinant luciferase reporter gene–based cell bioassay that has been used in combination with chemical extraction and cleanup methods for the relatively rapid and inexpensive detection and relative quantitation of dioxin and dioxin-like chemicals in a wide variety of sample matrices. Although the CALUX bioassay has been validated and used extensively for screening purposes, it has some limitations when screening samples with very low levels of dioxin-like chemicals or when there is only a small amount of sample matrix for analysis. Here, we describe the development of third-generation (G3) CALUX plasmids with increased numbers of dioxin-responsive elements, and stable transfection of these new plasmids into mouse hepatoma (Hepa1c1c7) cells has produced novel amplified G3 CALUX cell bioassays that respond to TCDD with a dramatically increased magnitude of luciferase induction and significantly lower minimal detection limit than existing CALUX-type cell lines. The new G3 CALUX cell lines provide a highly responsive and sensitive bioassay system for the detection and relative quantitation of very low levels of dioxin-like chemicals in sample extracts. PMID:21775728

Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like coplanar polychlorinated biphenyls in mackerel obtained from the Japanese market, 1999-2003.

Science.gov (United States)

Nakatani, Tadashi; Yamano, Testuo

2017-09-01

This study analysed the concentrations and toxic-equivalent (TEQ) levels of dioxin congeners in mackerel commercially available in Japan in early 2000s. The content of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like coplanar polychlorinated biphenyls (DL-PCBs) was determined in 17 mackerel samples from different areas. TEQ levels in mackerel muscle were 0.78 pg TEQ g - 1 wet weight (wt) on average (range = 0.21-2.26 pg TEQ g - 1 wet wt) for PCDD/Fs (PCDDs plus PCDFs), 2.81 pg TEQ g - 1 wet wt on average (range = 1.02-8.5 pg TEQ g - 1 wet wt) for DL-PCBs, and 3.59 pg TEQ g - 1 wet wt on average (range = 1.24-10.8 pg g - 1 wet wt) for dioxins (PCDD/Fs plus DL-PCBs). The results revealed somewhat higher TEQ levels for dioxins compared with the other data for fish and shellfish in the Japanese market. TEQ levels were well correlated with mackerel body weight; the main contributors were tetra- and penta-CDD/Fs, some hexa-CDD/Fs, and all 12 DL-PCBs, which are known to have high bioaccumulation potential. In particular, PCB 126 was mostly responsible for the observed correlation of DL-PCB and dioxins-TEQ levels with mackerel body weight. The average daily intake of dioxins in terms of TEQ through mackerel consumption was estimated to be 4.81 pg TEQ/person/day, accounting for 7% of the total intake of dioxins-TEQ through fish and shellfish in Japan.

Microarray analysis of gene expression in peripheral blood mononuclear cells from dioxin-exposed human subjects

International Nuclear Information System (INIS)

McHale, Cliona M.; Zhang, Luoping; Hubbard, Alan E.; Zhao, Xin; Baccarelli, Andrea; Pesatori, Angela C.; Smith, Martyn T.; Landi, Maria Teresa

2007-01-01

Tetrachlorodibenzo-p-dioxin (TCDD) is classified as a human carcinogen and exerts toxic effects on the skin (chloracne). Effects on reproductive, immunological, and endocrine systems have also been observed in animal models. TCDD acts through the aryl hydrocarbon receptor (AhR) pathway influencing largely unknown gene networks. An industrial accident in Seveso, Italy in 1976 exposed thousands of people to substantial quantities of TCDD. Twenty years after the exposure, this study examines global gene expression in the mononuclear cells of 26 Seveso female never smokers, with similar age, alcohol consumption, use of medications, and background plasma levels of 22 dioxin congeners unrelated to the Seveso accident. Plasma dioxin levels were still elevated in the exposed subjects. We performed analyses in two different comparison groups. The first included high-exposed study subjects compared with individuals with background TCDD levels (average plasma levels 99.4 and 6.7 ppt, respectively); the second compared subjects who developed chloracne after the accident, and those who did not develop this disease. Overall, we observed a modest alteration of gene expression based on dioxin levels or on chloracne status. In the comparison between high levels and background levels of TCDD, four histone genes were up-regulated and modified expression of HIST1H3H was confirmed by real-time PCR. In the comparison between chloracne case-control subjects, five hemoglobin genes were up-regulated. Pathway analysis revealed two major networks for each comparison, involving cell proliferation, apoptosis, immunological and hematological disease, and other pathways. Further examination of the role of these genes in dioxin induced-toxicity is warranted

Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on signal transduction pathway-related protein expression in liver and cerebrum of rhesus monkey

Energy Technology Data Exchange (ETDEWEB)

Ohta, Mari; Akema, Satoshi; Tsuzuki, Masami; Kubota, Shunichiro [Tokyo Univ. (Japan); Korenaga, Tatsumi; Fukusato, Toshio [Teikyo Univ. of School of Medicine, Tokyo (Japan); Asaoka, Kazuo [Kyoto Univ. (Japan); Murata, Nobuo [Teikyo Univ. of School of Medicine, Kawasaki (Japan); Nomizu, Motoyoshi [Hokkaido Univ., Sapporo (Japan); Arima, Akihiro [Shin Nippon Biomedical Laboratories, Ltd., Kagoshima (Japan)

2004-09-15

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is known to produce a wide range of toxic and biochemical effects in experimental animals, including immunological dysfunctions, chloracne, tetragenecity and carcinogenesis. Recently, the potential impact of dioxins on neurological disorders with particular focus on attention deficit hyperactivity disorder (ADHD) are concerned. Although a lot of information is available from studies in rodents, not much is known of the low dose effects of TCDD in non-human primates. In higher animals, dioxins are metabolized slowly, as evidenced by the estimated TCDD half-life of 5.8 to 14.1 years. Therefore, it is necessary to investigate the long-term effects of TCDD on human health. Considering the pronounced species differences observed in some studies of TCDD, the studies using primates are needed for assessment of TCDD exposure on human health. We have been studying the metabolism and the effects of single administration of TCDD on pregnant monkey (F0) and F1 rhesus monkey. The focus of the present study is to study the effects of TCDD on signal transduction pathway-related protein levels in various organs, especially in liver and brain of F0 monkeys.

Low dose CT perfusion in acute ischemic stroke

International Nuclear Information System (INIS)

Murphy, Amanda; Symons, Sean; Jakubovic, Raphael; Zhang, Liying; Aviv, Richard I.; So, Aaron; Lee, Ting-Yim

2014-01-01

The purpose of this investigation is to determine if CT perfusion (CTP) measurements at low doses (LD = 20 or 50 mAs) are similar to those obtained at regular doses (RD = 100 mAs), with and without the addition of adaptive statistical iterative reconstruction (ASIR). A single-center, prospective study was performed in patients with acute ischemic stroke (n = 37; 54 % male; age = 74 ± 15 years). Two CTP scans were performed on each subject: one at 100 mAs (RD) and one at either 50 or 20 mAs (LD). CTP parameters were compared between the RD and LD scans in regions of ischemia, infarction, and normal tissue. Differences were determined using a within-subjects ANOVA (p 0.05). CTP-derived CBF and CBV are not different at 50 mAs compared to 100 mAs, even without the addition of ASIR. Current CTP protocols can be modified to reduce the effective dose by 50 % without altering CTP measurements. (orig.)

Mechanisms of Low Dose Radiation-induced T helper Cell Function

International Nuclear Information System (INIS)

Gridley, Daila S.

2008-01-01

Exposure to radiation above levels normally encountered on Earth can occur during wartime, accidents such as those at Three Mile Island and Chernobyl, and detonation of 'dirty bombs' by terrorists. Relatively high levels of radiation exposure can also occur in certain occupations (low-level waste sites, nuclear power plants, nuclear medicine facilities, airline industry, and space agencies). Depression or dysfunction of the highly radiosensitive cells of the immune system can lead to serious consequences, including increased risk for infections, cancer, hypersensitivity reactions, poor wound healing, and other pathologies. The focus of this research was on the T helper (Th) subset of lymphocytes that secrete cytokines (proteins), and thus control many actions and interactions of other cell types that make up what is collectively known as the immune system. The Department of Energy (DOE) Low Dose Radiation Program is concerned with mechanisms altered by exposure to high energy photons (x- and gamma-rays), protons and electrons. This study compared, for the first time, the low-dose effects of two of these radiation forms, photons and protons, on the response of Th cells, as well as other cell types with which they communicate. The research provided insights regarding gene expression patterns and capacity to secrete potent immunostimulatory and immunosuppressive cytokines, some of which are implicated in pathophysiological processes. Furthermore, the photon versus proton comparison was important not only to healthy individuals who may be exposed, but also to patients undergoing radiotherapy, since many medical centers in the United States, as well as worldwide, are now building proton accelerators. The overall hypothesis of this study was that whole-body exposure to low-dose photons (gamma-rays) will alter CD4+ Th cell function. We further proposed that exposure to low-dose proton radiation will induce a different pattern of gene and functional changes compared to

Rapid measurement of polychlorinated dibenzo-p-dioxins and dibenzofurans and planar chlorobiphenyls using microcolumn chromatography

Energy Technology Data Exchange (ETDEWEB)

King, T.L.; Haines, B.K.; Tokarczyk, R.; Uthe, J.F. [Department of Fisheries and Oceans, Halifax, NS (Canada). Biological Sciences Branch

1997-05-01

The concentration of polychlorinated dibenzo-p-dioxin, dibenzofuran classes and chlorobiphenyl in lobster from Atlantic Canada was measured using a newly developed quick and low-cost measuring method. The method is based on saponification followed by extraction into hexane, clean-up by gel-permeation chromatography and sulfuric acid treatment, and the separation of the non-ortho-chlorinated chlorobiphenyls and polychlorinated dibenzo-p-dioxins and dibenzofurans from other chlorinated compounds. Detection limits as low as 1-5 pg.g{sup -1} wet wt. were achieved for some of the chlorinated compounds.

Inventory of U.S. 2012 dioxin emissions to atmosphere.

Science.gov (United States)

Dwyer, Henri; Themelis, Nickolas J

2015-12-01

In 2006, the U.S. EPA published an inventory of dioxin emissions for the U.S. covering the period from 1987-2000. This paper is an updated inventory of all U.S. dioxin emissions to the atmosphere in the year 2012. The sources of emissions of polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), collectively referred to in this paper as "dioxins", were separated into two classes: controlled industrial and open burning sources. Controlled source emissions decreased 95.5% from 14.0 kg TEQ in 1987 to 0.6 kg in 2012. Open burning source emissions increased from 2.3 kg TEQ in 1987 to 2.9 kg in 2012. The 2012 dioxin emissions from 53 U.S. waste-to-energy (WTE) power plants were compiled on the basis of detailed data obtained from the two major U.S. WTE companies, representing 84% of the total MSW combusted (27.4 million metric tons). The dioxin emissions of all U.S. WTE plants in 2012 were 3.4 g TEQ and represented 0.54% of the controlled industrial dioxin emissions, and 0.09% of all dioxin emissions from controlled and open burning sources. Copyright © 2015. Published by Elsevier Ltd.

PROFOUND AND SEXUALLY DIMORPHIC EFFECTS OF CLINICALLY-RELEVANT LOW DOSE SCATTER IRRADIATION ON THE BRAIN AND BEHAVIOR

Directory of Open Access Journals (Sweden)

Anna eKovalchuk

2016-06-01

Full Text Available Irradiated cells can signal damage and distress to both close and distant neighbors that have not been directly exposed to the radiation (naïve bystanders. While studies have shown that such bystander effects occur in the shielded brain of animals upon body irradiation, their mechanism remains unexplored. Observed effects may be caused by some blood-borne factors; however they may also be explained, at least in part, by very small direct doses received by the brain that result from scatter or leakage. In order to establish the roles of low doses of scatter irradiation in the brain response, we developed a new model for scatter irradiation analysis whereby one rat was irradiated directly at the liver and the second rat was placed adjacent to the first and received a scatter dose to its body and brain. This work focuses specifically on the response of the latter rat brain to the low scatter irradiation dose. Here, we provide the first experimental evidence that very low, clinically relevant doses of scatter irradiation alter gene expression, induce changes in dendritic morphology, and lead to behavioral deficits in exposed animals. The results showed that exposure to radiation doses as low as 0.115 cGy caused changes in gene expression and reduced spine density, dendritic complexity, and dendritic length in the prefrontal cortex tissues of females, but not males. In the hippocampus, radiation altered neuroanatomical organization in males, but not in females. Moreover, low dose radiation caused behavioral deficits in the exposed animals. This is the first study to show that low dose scatter irradiation influences the brain and behavior in a sex-specific way.

Perinatal exposure to dioxins and dioxin-like compounds and infant growth and body mass index at seven years: A pooled analysis of three European birth cohorts.

Science.gov (United States)

Iszatt, Nina; Stigum, Hein; Govarts, Eva; Murinova, Lubica Palkovicova; Schoeters, Greet; Trnovec, Tomas; Legler, Juliette; Thomsen, Cathrine; Koppen, Gudrun; Eggesbø, Merete

2016-09-01

Dioxins and dioxin-like compounds are endocrine disrupting chemicals (EDCs). Experimental studies suggest perinatal exposure to EDCs results in later obesity. However, the few epidemiological investigations on dioxins are inconclusive. We investigated perinatal exposure to dioxins and dioxin-like compounds, infant growth and body mass index (BMI) in childhood. We pooled data from 3 European birth cohorts (Belgian, Norwegian, Slovak) with exposure assessment in cord blood or breast milk. Two cohorts had dioxin-like toxicity assessed using dioxin-responsive chemical-activated luciferase expression (DR-CALUX) bioassay and one cohort had measured concentrations of dioxins, furans and dioxin-like polychlorinated biphenols with CALUX relative potency values applied. Growth was cohort- and sex-specific change in weight-for-age z-score between birth and 24months (N=367). BMI was calculated at around 7years (median 7.17, interquartile range [IQR] 7.00-7.37years, N=251), and overweight defined according to international standards for children equivalent to adult BMI >25kg/m(2) (Cole and Lobstein, 2012). We fitted multivariate models using generalized estimating equations, and tested effect modification by sex, breastfeeding and cohort. Results per 10pgCALUXTEQ/g lipid increase in exposure. Dioxin exposure was highest in the Belgian and lowest in the Norwegian cohort; median (IQR) of the pooled sample 13 (12.0) pgCALUXTEQ/g lipid. Perinatal exposure to dioxins and dioxin-like compounds appeared associated with increased growth between 0 and 24months (adjusted estimate for change in z-score: β=0.07, 95% CI: -0.01, 0.14). At 7years, dioxins exposure was associated with a statistically significant increase in BMI in girls (adjusted estimate for BMI units β=0.49, 95% CI: 0.07, 0.91) but not in boys (β=-0.03, 95% CI: -0.55, 0.49) (p-interaction=0.044). Furthermore, girls had a 54% (-6%, 151%) increased risk of overweight at 7years (p-interaction=0.023). Perinatal exposure to

In utero and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) affects tooth development in rhesus monkeys

Energy Technology Data Exchange (ETDEWEB)

Yasuda, Iku; Kazuhiro, Tsuga; Yasumasa, Akagawa [Hiroshima Univ. (Japan); Mineo, Yasuda; Hiroshi, Sumida [Hiroshima International Univ. (Japan); Akihiro, Arima; Toshio, Ihara [Shin Nippon Biomedical Laboratories, Ltd., Kagoshima (Japan); Shunichiro, Kubota [Tokyo Univ. (Japan); Kazuo, Asaoka [Kyoto Univ., Inuyama (Japan). Primate Research Institute; Takumi, Takasuga [Shimadzu Techno-Research Inc., Kyoto (Japan)

2004-09-15

The current tolerable daily intake (TDI) of dioxin and dioxin related compounds has been set at 4 pg TEQ/kg/day in Japan. This value was calculated from the lowest-observed-adverse-effect level (LOAEL) in experimental animals, mostly rodents. Gray et al. reported that a single oral dose of 200 ng/kg of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to pregnant rats on day 15 of gestation resulted in abnormalities of reproductive organs in the offspring. The maternal body burden at this dose was measured to be 86 ng/kg. To attain this body burden level, human daily intake was calculated to be 43.6 pg/kg/day. An uncertainty factor of 10 was applied to this value, and the human TDI was established. However, due to great differences in the biological half life of TCDD between human and rodents, the validity of this calculation is questioned. To obtain more reliable LOAEL in the second generation, we initiated a long-term study in rhesus monkeys in 1999. In rodents, teeth are known to be targets of developmental toxicity of dioxin. In utero and lactational TCDD exposure affects rat incisor and molar development. In humans also tooth abnormalities were reported among populations exposed to dioxins. In our monkey experiment, some young were stillborn or died neonatally. These animals provided us with a unique opportunity to study tooth development in primate young exposed to TCDD in utero and lactationally. By macroscopic observation we found some tooth abnormalities among died young exposed to TCDD5. This prompted us to examine surviving young by radiography. This is an interim report of our findings in these young.

Pentachlorophenol from an old henhouse as a dioxin source in eggs and related human exposure

International Nuclear Information System (INIS)

Piskorska-Pliszczynska, Jadwiga; Strucinski, Pawel; Mikolajczyk, Szczepan; Maszewski, Sebastian; Rachubik, Jaroslaw; Pajurek, Marek

2016-01-01

High levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were detected in free-range eggs, and these levels reached a concentration of 29.84 ± 7.45 pg of WHO-TEQ/g of fat. This value exceeded the EU maximum permitted level of 2.5 pg of WHO-TEQ/g of fat for PCDD/F congeners by twelve-fold. A chemical analysis (HRGC-HRMS) revealed elevated amounts of OCDD, OCDF, HxCDD, HpCDD and HpCDF. During the investigation, samples of feed, soil, wall scrapings, wooden ceiling of the henhouse and tissues from laying hens were examined for dioxin contents (30 samples altogether). The long and complicated investigation found that the source of dioxins in the poultry farm was pentachlorophenol-treated wood, which was used as structural components in the 40-year-old farm building adapted to a henhouse. The wooden building material contained PCDD/Fs at a concentration of 3922.60 ± 560.93 pg of WHO-TEQ/g and 11.0 ± 2.8 μg/kg of PCP. The potential risk associated with dioxin intake was characterized by comparing the theoretically calculated weekly and monthly intakes with the toxicological reference values (TRVs), namely the Tolerable Weekly Intake (TWI) and Provisional Tolerable Monthly Intake (PTMI) values of 14 pg of WHO-TEQ/kg of bw and 70 pg of WHO-TEQ/kg of bw, respectively. The intake of dioxins estimated for high egg consumers (approximately 5–6 eggs/week) exceeded the TWI and PTMI values, which may pose a risk of delayed adverse health effects. The estimated dose of PCDD/Fs and DL-PCBs for children consuming 5 eggs per week exceeded the TWI by as much as 450% because of their nearly 5-fold-lower body weight. Although the dioxin intake estimated for the average consumption of eggs in the general population did not exceed any of the TRVs applied (58.7% TWI and 51.1% PTMI), such a situation should be considered unacceptable from a public health perspective because eggs are not the only source of these contaminants

Emissions of chlorinated dioxins and furans

International Nuclear Information System (INIS)

Broeker, G.; Bruckmann, P.; Gliwa, H.

1994-01-01

Already now the estimated daily average input of about 2 pg I-TEQ/kg body weight for an adult exceeds the preventive value of 1 pg I-TEQ/(kg x d) proposed by the Federal Environmental Agency (UBA) and the Federal Health Office (BGA), although the intervention value of 10 pg/(kg x d) also proposed by UBA and BGA has not been reached yet. To be able to take well-aimed measures to reduce dioxin emissions into the environment, it is necessary to collect sufficient information about the sources, the history of origins and the efficiency of control measures. The high number of investigations conducted into waste incineration plants, which can be explained by increasing public awareness of the disposal problem, gave the impression that waste incineration is one of the major causes of dioxin emissions into the environment. Analyses of the ambient air situation revealed that there is a considerable lack of information about the sources of dioxin emissions. For example, systematic investigations in North Rhine-Westphalia, which have not been finished yet, identified sintering plants as the main dioxin emittors. It can be concluded already now that control measures are indispensable for these plants to improve the ambient air situation; a few waste gas cleaning methods were tested. The realisation of the 17th Order Implementing the Federal Immission Control Act (17th BImSchV) (emission control of dioxins from waste incineration plants), the 19th BImSchV (prohibition of Cl and Br additions to fuels) and the further spread of the controlled catalytic coverter for passenger cars will make industrial dioxin sources even more relevant. This underlines the necessity for control measures in this field. (orig.) [de

Radioimmunoassay for chlorinated dibenzo-p-dioxins

International Nuclear Information System (INIS)

Albro, P.W.; Chae, K.; Luster, M.I.; Mckinney, J.D.

1980-01-01

The invention provides a double-antibody radioimmunoassay method for the determination of chlorinated dibenzo-p-dioxins, particularly, 2,3,7,8-tetrachlorodibenzo-p-dioxin, in environmental samples including animal tissues such as monkey liver and adipose tissues. The limit of detection is approximately 25 picograms for 2,3,7,8-tetrachlorodibenzo-pdioxin. Assuming an appropriate cleanup procedure is used, chlorinated dibenzofurans are the only likely interferences, and these can be distinguished through the use of two antisers of different dibenzo-furan/dibenzodioxin selectivities. The invention includes the preparation of a reproducible antigen, an appropriate radiolabeled hapten, and effective sample extracts. A feature of the assay method is the use of a nonionic detergent (e.g., ''cutscum'' or ''triton x-305'') to solubilize the extremely hydrophobic dibenzo-p-dioxins in a manner permitting their binding by antibodies. The immunoassay is applicable to screening samples in order to minimize the demand for mass spectrometric screening, and to routine monitoring for exposure to known chlorinated dibenzo-p-dioxins in potentially contaminated environments

New data for the discussion about combustion, dioxin and health; Nuevas aportaciones al controvertido debate sobre incineracion, dioxinas y salud

Energy Technology Data Exchange (ETDEWEB)

Domingo, S. L. [Universidad Rovira i Virgili. Reus. Tarragona (Spain)

2000-07-01

Dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD) is created unintentionally as a byproduct of human activities such as combustion, paper belaching, and manufacture of chlorine and organochlorine chemicals. Most information concerning human health risks of dioxin is based on highly exposed industrial cohorts with well established high levels of exposure to TCDD. However, information regarding to the health effects from chronic exposure to low levels of dioxin is very scarce. This paper has two main goals. Firstly, to review the most known international affairs related with a massive exposure to dioxin. Secondly, to assess if the pronounced reduction detected in the emissions of dioxins and furans by the MSWI of Tarragona (Spain) would also result in a notable decrease in the levels of dioxins in environmental matrices collected in the vicinity of the MSWI. The current results show that in comparison with the emission sources of dioxins and furans in the same area of the facility, the health risks due to the current emissions of dioxins and furans by the plant would be of small significance for the population living in the neighbour hod. Moreover, we also show that the daily consumption of 200 g/day of semiskimmed milk instead of the same amount of whole milk would be much more relevant to decrease dioxin exposure that the reduction in dioxin emissions resulting from the technical improvements carried out recently in the MSWI. (Author)

Repair and dose-response at low doses

International Nuclear Information System (INIS)

Totter, J.R.; Weinberg, A.M.

1977-04-01

The DNA of each individual is subject to formation of some 2-4 x 10 14 ion pairs during the first 30 years of life from background radiation. If a single hit is sufficient to cause cancer, as is implicit in the linear, no-threshold theories, it is unclear why all individuals do not succumb to cancer, unless repair mechanisms operate to remove the damage. We describe a simple model in which the exposed population displays a distribution of repair thresholds. The dose-response at low dose is shown to depend on the shape of the threshold distribution at low thresholds. If the probability of zero threshold is zero, the response at low dose is quadratic. The model is used to resolve a longstanding discrepancy between observed incidence of leukemia at Nagasaki and the predictions of the usual linear hypothesis

Dioxin in the atmosphere of Denmark

Energy Technology Data Exchange (ETDEWEB)

Vikelsoee, J.; Hovmand, M.F.; Andersen, Helle V.; Bossi, R.; Johansen, Elsebeth; Chrillesen, M.A.

2006-03-15

Occurrence and geographical distribution of dioxin was investigated in air and deposition at selected locations in Denmark, three forest sites in the background area, a city site in Copenhagen and a village site. At two sites simultaneously determination of dioxins concentrations in the ambient atmosphere and bulk precipitation were carried out during a period of three years. (au)

Alterations in brain metabolism and function following administration of low-dose codeine phosphate: 1H-magnetic resonance spectroscopy and resting-state functional magnetic resonance imaging studies

OpenAIRE

Cao, Zhen; Lin, Pei-Yin; Shen, Zhi-Wei; Wu, Ren-Hua; Xiao, Ye-Yu

2016-01-01

The aim of the present study was to identify alterations in brain function following administration of a single, low-dose of codeine phosphate in healthy volunteers using resting-state functional magnetic resonance imaging (fMRI). In addition, the metabolic changes in the two sides of the frontal lobe were identified using 1H-magnetic resonance spectroscopy (1H-MRS). A total of 20 right-handed healthy participants (10 males, 10 females) were evaluated, and a Signa HDx 1.5T MRI scanner was use...

Impact of perinatal dioxin exposure on infant growth: a cross-sectional and longitudinal studies in dioxin-contaminated areas in Vietnam.

Directory of Open Access Journals (Sweden)

Muneko Nishijo

Full Text Available Dioxin exposure levels remain elevated in residents living around former US Air Force bases in Vietnam, indicating potential adverse impacts on infant growth. In this study, 210 mother-infant pairs in dioxin-contaminated areas in Vietnam were recruited at the infants' birth and followed up for 4 months. Perinatal dioxin exposure levels were estimated by measurement of polychlorinated dibenzo-p-dioxins/furans toxic equivalent (PCDDs/Fs-TEQ in breast milk. The infants' size was measured at birth and 1 and 4 months after birth, and neurodevelopment was evaluated using the Bayley Scales III at 4 months of age. Among 4 dioxin groups (<25, 25-50, 50-75, ≥75 percentile of PCDDs/Fs-TEQ, cross-sectional comparisons of body size and neurodevelopment scales and comparisons of longitudinally assessed body size were performed respectively. At birth, head circumference of girls in the ≥75 percentile group was significantly larger than those in the <25 and 50-75 percentile groups. At 4 months of age, the weight and body mass index (BMI of boys in the ≥75 percentile group were significantly lower than those in the other groups. Increase in weight was significantly lower in the ≥75 percentile group in both sexes from birth to 1 month but only in boys at 1-4 months of age. Estimated marginal mean values in a mixed model of weight and BMI during the first 4 months of life were significantly lower in the ≥75 percentile group in boys. In girls, marginal mean values for head circumference were increased with increase in dioxin levels. Only in boys, cognitive, language, and fine motor scores in the ≥75 percentile group were significantly lower than those in the other groups. These results suggested a considerable impact of perinatal dioxin exposure on infant growth, particularly in boys exposed to dioxins at high level of PCDDs/Fs-TEQ.

Responses of epithelial cells to low and very low doses of low let radiation

International Nuclear Information System (INIS)

Mothersill, Carmel; Seymour, Colin

2003-01-01

Recent advances in our knowledge of the biological effects of low doses of ionizing radiation have shown unexpected phenomena. These vary in the endpoint used to detect them and in the dose range examined but all occur as high-frequency events in cell populations. They include: 1. a 'bystander effect' which can be demonstrated at low doses as a transferable.factor(s) causing radiobiological effects in unexposed cells, 2. an assortment of delayed effects' occurring in progeny of cells exposed to low doses, 3. Low-dose Hypersensitivity (HRS) and Increased radioresistance (IRR) which can collectively be demonstrated as a change in the dose-effect relationship, occurring around 0.5-1 Gy of low LET radiation and 4. adaptive responses where cells exposed to very low doses followed by higher doses, exhibit an induced relatively resistant response to the second dose. In all cases, the effect of very low doses is greater than would be predicted by extrapolation of high dose data and is inconsistent with conventional DNA break/repair-based radiobiology. In practical risk assessment terms, the relative importance of the effects are high at low doses where they dominate the response, and small at high doses. This paper reviews these assorted phenomena and in particular seeks to explore whether related or distinct mechanisms underlie these various effects Understanding the mechanistic basis of these phenomena may suggest new approaches to controlling death or survival sectoring at low radiation doses. The key question is whether these low dose phenomena necessitate a new approach to risk assessment. (author)

An Aryl Hydrocarbon Receptor from the Salamander Ambystoma mexicanum Exhibits Low Sensitivity to 2,3,7,8-Tetrachlorodibenzo-p-dioxin.

Science.gov (United States)

Shoots, Jenny; Fraccalvieri, Domenico; Franks, Diana G; Denison, Michael S; Hahn, Mark E; Bonati, Laura; Powell, Wade H

2015-06-02

Structural features of the aryl hydrocarbon receptor (AHR) can underlie species- and population-specific differences in its affinity for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). These differences often explain variations in TCDD toxicity. Frogs are relatively insensitive to dioxin, and Xenopus AHRs bind TCDD with low affinity. Weak TCDD binding results from the combination of three residues in the ligand-binding domain: A354 and A370, and N325. Here we sought to determine whether this mechanism of weak TCDD binding is shared by other amphibian AHRs. We isolated an AHR cDNA from the Mexican axolotl (Ambystoma mexicanum). The encoded polypeptide contains identical residues at positions that confer low TCDD affinity to X. laevis AHRs (A364, A380, and N335), and homology modeling predicts they protrude into the binding cavity. Axolotl AHR bound one-tenth the TCDD of mouse AHR in velocity sedimentation analysis, and in transactivation assays, the EC50 for TCDD was 23 nM, similar to X. laevis AHR1β (27 nM) and greater than AHR containing the mouse ligand-binding domain (0.08 nM). Sequence, modeled structure, and function indicate that axolotl AHR binds TCDD weakly, predicting that A. mexicanum lacks sensitivity toTCDD toxicity. We hypothesize that this characteristic of axolotl and Xenopus AHRs arose in a common ancestor of the Caudata and Anura.

Low doses effects and gamma radiations low dose rates; Les effets des faibles doses et des faibles debits de doses de rayons gamma

Energy Technology Data Exchange (ETDEWEB)

Averbeck, D [Institut Curie, CNRS UMR 2027, 75 - Paris (France)

1999-07-01

This expose wishes for bringing some definitions and base facts relative to the problematics of low doses effects and low dose rates effects. It shows some already used methods and some actual experimental approaches by focusing on the effects of ionizing radiations with a low linear energy transfer. (N.C.)

The relationships between dioxin accumulation in human body and eating habits

Energy Technology Data Exchange (ETDEWEB)

Kajihara, H; Miura, A [Graduate School of Science and Technology, Univ. of Niigata, Niigata (Japan); Sasaki, S; Hasegawa, Y; Ando, N; Ozawa, T; Takahashi, Y [Faculty of Engineering, Univ. of Niigata, Niigata (Japan); Nakadaira, H; Yamamoto, M [Graduate School of Medical and Dental Sciences, Univ. of Niigata, Niigata (Japan); Nakamura, S; Shimada, K [Niigata Prefectural Kamo Hospital, Niigata (Japan)

2004-09-15

Exposure of human to dioxins was dominated by food. In Japan, the tolerable daily intake (TDI) of dioxins is set at 4 pg-TEQ/kg/day. However, important parameters, such as adsorption rate and half-life, which are used in the calculation process to determining the TDI of dioxins, were not intensively clarified. The objective of this study is to investigate the relationship between dioxin accumulation in the human body and eating habits, in order to obtain information on the accumulation behavior of dioxins ingested by humans.

Dioxins - essential characteristics. Pt. 3

International Nuclear Information System (INIS)

Brunn, H.

1993-01-01

'The dioxins' is the name of a large family of environmentally significant chemicals which, being stereoisomers of 2,3,7,8 TCDD, are all assumed to have similar effects. They include PCDD, PCDF, PBDD, PBDF, and possibly also a whole number of PCBs. Altogether, average ingestion of dioxins and furans in Germany amounts to a toxicity equivalent of 93.5 pg TCDD per person and day, 24.6 pg of which are 2,3,7,8 TCDD. Assuming the average weight of an adult to be 70 kg, this means an average ingestion of 1.3 pg TE/kg body weight and day. Fuerst et al. obtained similar results in their study on dioxin ingestion, average daily intake of dioxins and furans amounting to 85 pg TE per person. This is equivalent to an intake of 1.2 pg TE/kg body weight and day. Breaking down daily PCDD and PCDF intake by food category, the authors obtained the following data: Meat and meat products (beef, veal pork, chicken): 27.5 pg TE/person and day; fish and fish products 27 pg TE/person and day; milk and dairy products (milk, cheese, butter) 26.9 pg TE/person and day; vegetable oils (salad oil, margarine) 3.8 pg TE/person and day. This amounts to an overall intake of 85 pg TE/person and day. (orig./EF) [de

EFFECTS OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD) ON FETAL MOUSE URINARY TRACT EPITHELIUM IN VITRO

Science.gov (United States)

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), produces hydronephrosis by altering the differentiation and proliferation of ureteric epithelial cells in the embryonic C57BL/6N mouse urinary tract. This study examines the effects of TCDD on late gestation fetal urinary tract cells u...

Study of dioxin and dioxin-like PCB levels in fatty fish from Sweden 2000-2002

Energy Technology Data Exchange (ETDEWEB)

Ankarberg, E.; Bjerselius, R.; Aune, M.; Darnerud, P.O.; Larsson, L.; Andersson, A.; Toernkvist, A.; Glynn, A. [Swedish National Food Administration, Research and Development Dept., Uppsala (Sweden); Tysklind, M.; Bergek, S. [Environmental Chemistry, Umea Univ. (Sweden); Lundstedt-Enkel, K. [Dept. of Environmental Toxicology, Uppsala Univ. (Sweden); Karlsson, L. [Inst. of Freshwater Research, National Board of Fisheries, Aelvkarleby (Sweden)

2004-09-15

The levels of PCDD/Fs and PCBs in fatty fish from the Baltic Sea area are still of major concern in Sweden, although the levels have decreased in Baltic Sea biota since the 1970. During later years this decrease seems to have leveled off, and at least dioxin levels in Baltic herring seem to be more or less the same during the last 10 years period. Harmonised EU maximum levels have been established for PCDD/Fs in fish and fishery products for human consumption, and the maximum level is 4 pg WHO-PCDD/F-TEQ/g fresh weight. Certain fatty fish species in the Baltic Sea are shown to have levels of PCDD/Fs exceeding the maximum level. However, because of protective dietary advice, Sweden and Finland have an exemption from the Council regulation that allows national marketing of fish and fishery products that exceed the maximum level for PCDD/F. For dioxin-like PCBs, common EU maximum levels have not yet been established. However, during 2004 the Commission will review the present maximum levels for dioxins in the light of new data, with a particular aim to include dioxin-like PCBs. The Swedish National Food Administration (NFA) has undertaken a survey to analyse the concentrations of PCDD/Fs and dioxin-like PCBs in fatty fish in the Baltic Sea area. The study presents results from analyses of eel (Anguilla anguilla), salmon (Salmo salar), brown trout (Salmo trutta), whitefish (Coregonus lavaretus), herring (Clupea harengus), sprat (Sprattus sprattus), cod (Gadus morhua callarias) and vendace (roe) (from Coregonus albula) from several locations in the Baltic Sea. This study reports the fifth part of the results from the analyses. The entire study is available on www.slv.se as interim reports 1-5.

Dioxins and dioxin-like PCBs in fish in general and in particular from Baltic Sea

Energy Technology Data Exchange (ETDEWEB)

Karl, H. [Federal Research Centre for Nutrition and Food, Hamburg (Germany); Ruoff, U. [Federal Research Centre For Nutrition and Food, Kiel (Germany)

2004-09-15

Commission Regulation No 466/2001 establishes maximum levels for dioxins in foodstuffs, foreseeing to review the maximum levels by 31 December 2006 and to include dioxin-like PCBs in the levels to be set. Fish is known to accumulate dioxins and dioxin related compounds in the lipid phase of their tissue. To collect information of the actual contamination levels in fish species on the German market, samples were taken from fishing grounds important for the supply and in particular from the Baltic Sea. Sampling concentrates on fish species with higher fat content like mackerel (Scomber scombrus), salmon (Salmo salar), trout (Oncorhynchus mykiss), red fish (Sebastes sp.) and herring (Clupea harengus), because lean fish species are known to be less contaminated. Herring is the most important fat fish species for the German fish processing industry with a market share of 19% in 2001. The annual demand is approximately 149.000 t. Herring and other fish species accumulate PCDD/Fs with increasing age and dioxin levels in the edible part of eastern Baltic herring exceeds the maximum limit of 4 ng WHOPCDD/ F-TEQ/kg wet weight (w.w.) at ages of 4 - 6 years, corresponding to sizes of approximately 17 - 18 cm and a weight of 40 g, respectively. Hence Isosaari recommended to use preferably young fish from this area for human consumption. However, the German herring industry is based on the processing of large herring with a minimum weight of > 85g up to 250g. Therefore our interest focused on herring sizes of potential interest for the German processing industry. Samples were collected in September 1999 within two weeks covering an area from the Skagerrak to the Coast of Latvia. Additionally the contamination levels in sprat (Sprattus sprattus), flounder, brown trout (Salmo trutta) and in spring spawning herring from commercial landings around the area of Ruegen have been analysed.

Low dose diagnostic radiation does not increase cancer risk in cancer prone mice

Energy Technology Data Exchange (ETDEWEB)

Boreham, D., E-mail: dboreham@nosm.ca [Northern Ontario School of Medicine, ON (Canada); Phan, N., E-mail: nghiphan13@yahoo.com [Univ. of Ottawa, Ottawa, ON (Canada); Lemon, J., E-mail: lemonja@mcmaster.ca [McMaster Univ., Hamilton, ON (Canada)

2014-07-01

The increased exposure of patients to low dose diagnostic ionizing radiation has created concern that these procedures will result in greater risk of carcinogenesis. However, there is substantial evidence that shows in many cases that low dose exposure has the opposite effect. We have investigated whether CT scans can modify mechanisms associated with carcinogenesis in cancer-prone mice. Cancer was induced in Trp53+/- mice with an acute high dose whole-body 4 Gy γ-radiation exposure. Four weeks following the cancer-inducing dose, weekly whole-body CT scans (10 mGy/scan, 75 kVp X-rays) were given for ten consecutive weeks adding an additional radiation burden of 0.1 Gy. Short-term biological responses and subsequent lifetime cancer risk were investigated. Five days following the last CT scan, there were no detectable differences in the spontaneous levels of DNA damage in blood cells (reticulocytes). In fact, CT scanned mice had significantly lower constitutive levels of oxidative DNA damage and cell death (apoptosis), compared to non-CT scanned mice. This shows that multiple low dose radiation exposures modified the radio response and indicates protective processes were induced in mice. In mice treated with the multiple CT scans following the high cancer-inducing 4 Gy dose, tumour latency was increased, significantly prolonging lifespan. We conclude that repeated CT scans can reduce the cancer risk of a prior high-dose radiation exposure, and delay the progression of specific types of radiation-induced cancers in Trp53+/-mice. This research shows for the first time that low dose exposure long after cancer initiation events alter risk and reduce cancer morbidity. Cancer induction following low doses does not follow a linear non-threshold model of risk and this model should not be used to extrapolate risk to humans following low dose exposure to ionizing radiation. (author)

Emission of Dioxins from Danish Wood-Stoves

DEFF Research Database (Denmark)

Vikelsøe, J.; Madsen, Henrik; Hansen, K.

1994-01-01

The main purpose of the investigation was to estimate the annual dioxin emission from Danish wood-stoves. 4 stoves of different designs and 3 types of fuel were tested in 2 operating conditions. Sampling was carried out in a dilution tunnel, making reproducible sampling possible. The dioxin...

Mitochondrial-Derived Oxidants and Cellular Responses to Low Dose/Low LET Ionizing Radiation

International Nuclear Information System (INIS)

Spitz, Douglas R.

2009-01-01

Exposure to ionizing radiation results in the immediate formation of free radicals and other reactive oxygen species (ROS). It has been assumed that the subsequent injury processes leading to genomic instability and carcinogenesis following radiation, derive from the initial oxidative damage caused by these free radicals and ROS. It is now becoming increasingly obvious that metabolic oxidation/reduction (redox) reactions can be altered by irradiation leading to persistent increases in steady-state levels of intracellular free radicals and ROS that contribute to the long term biological effects of radiation exposure by causing chronic oxidative stress. The objective during the last period of support (DE-FG02-05ER64050; 5/15/05-12/31/09) was to determine the involvement of mitochondrial genetic defects in metabolic oxidative stress and the biological effects of low dose/low LET radiation. Aim 1 was to determine if cells with mutations in succinate dehydrogenase (SDH) subunits C and D (SDHC and SDHD in mitochondrial complex II) demonstrated increases in steady-state levels of reactive oxygen species (ROS; O 2 - and H 2 O 2 ) as well as demonstrating increased sensitivity to low dose/low LET radiation (10 cGy) in cultured mammalian cells. Aim No.2 was to determine if mitochondrially-derived ROS contributed to increased sensitivity to low dose/low LET radiation in mammalian cells containing mutations in SDH subunits. Aim No.3 was to determine if a causal relationship existed between increases in mitochondrial ROS production, alterations in electron transport chain proteins, and genomic instability in the progeny of irradiated cells. Evidence gathered in the 2005-2009 period of support demonstrated that mutations in genes coding for mitochondrial electron transport chain proteins (ETC); either Succinate Dehydrogenase (SDH) subunit C (SDHC) or subunit D (SDHD); caused increased ROS production, increased genomic instability, and increased sensitivity to low dose/low LET

Low and very low doses, new recommendations?

International Nuclear Information System (INIS)

Foucher, N.

1999-01-01

The topic of the seminar organized by the world council of nuclear workers (WONUC) was the effects of low or very low doses on human health. Discussions centred round the linearity of the relation between dose and effect in the evaluation and management of the health hazard. The recommendations proposed by ICPR (international commission for radiological protection) are based on this linearity as a precaution. On the one hand it is remembered that low dose irradiation might be beneficial. It has been proved that the irradiation of the whole body is efficient in case of Hodgkin lymphoma. On the other hand it is remembered that doses as low as 10 mSv in utero have led to an excess of cancer in children. Studies based on experimentally radio-induced cancers have been carried out in Japan, China, Canada and France.Their results seem to be not consistent with the hypothesis of linearity. During the last decade a lot of work has been made but a conclusion is far to be reached, it is said that the American department of energy (DOE) has invited bids in 1999 to launch research programs in order to clarify the situation. (A.C.)

Scientific opinion on the assessment of a decontamination process for dioxins and dioxin-like PCBs in fish oil by physical filtration with activated carbon

DEFF Research Database (Denmark)

Petersen, Annette

the amount of dioxins (polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs)) and dioxin-like polychlorinated biphenyls (DL-PCBs). All feed decontamination processes must comply with the acceptability criteria specified in the Commission Regulation (EU) 2015/786. The data...... to demonstrate the safe disposal of the waste material. The CONTAM Panel concluded that on the basis of the information submitted by the feed business operator the proposed decontamination process to remove dioxins (PCDD/Fs) and DL-PCBs from the fish oil by means of physical filtration with activated carbon...

Final Report - Epigenetics of low dose radiation effects in an animal model

Energy Technology Data Exchange (ETDEWEB)

Kovalchuk, Olga

2014-10-22

This project sought mechanistic understanding of the epigenetic response of tissues as well as the consequences of those responses, when induced by low dose irradiation in a well-established model system (mouse). Based on solid and extensive preliminary data we investigated the molecular epigenetic mechanisms of in vivo radiation responses, particularly – effects of low, occupationally relevant radiation exposures on the genome stability and adaptive response in mammalian tissues and organisms. We accumulated evidence that low dose irradiation altered epigenetic profiles and impacted radiation target organs of the exposed animals. The main long-term goal was to dissect the epigenetic basis of induction of the low dose radiation-induced genome instability and adaptive response and the specific fundamental roles of epigenetic changes (i.e. DNA methylation, histone modifications and miRNAs) in their generation. We hypothesized that changes in global and regional DNA methylation, global histone modifications and regulatory microRNAs played pivotal roles in the generation and maintenance low-dose radiation-induced genome instability and adaptive response. We predicted that epigenetic changes influenced the levels of genetic rearrangements (transposone reactivation). We hypothesized that epigenetic responses from low dose irradiation were dependent on exposure regimes, and would be greatest when organisms are exposed in a protracted/fractionated manner: fractionated exposures > acute exposures. We anticipated that the epigenetic responses were correlated with the gene expression levels. Our immediate objectives were: • To investigate the exact nature of the global and locus-specific DNA methylation changes in the LDR exposed cells and tissues and dissect their roles in adaptive response • To investigate the roles of histone modifications in the low dose radiation effects and adaptive response • To dissect the roles of regulatory microRNAs and their targets in low

Ameliorative effects of low dose/low dose-rate irradiation on reactive oxygen species-related diseases model mice

International Nuclear Information System (INIS)

Nomura, Takaharu

2008-01-01

Living organisms have developed complex biological system which protects themselves against environmental radiation, and irradiation with proper dose, dose-rate and irradiation time can stimulate their biological responses against oxidative stress evoked by the irradiation. Because reactive oxygen species are involved in various human diseases, non-toxic low dose/low dose-rate radiation can be utilized for the amelioration of such diseases. In this study, we used mouse experimental models for fatty liver, nephritis, diabetes, and ageing to elucidate the ameliorative effect of low dose/low dose-rate radiation in relation to endogenous antioxidant activity. Single irradiation at 0.5 Gy ameliorates carbon tetrachloride-induced fatty liver. The irradiation increases hepatic anti-oxidative system involving glutathione and glutathione peroxidase, suggesting that endogenous radical scavenger is essential for the ameliorative effect of low dose radiation on carbon tetrachloride-induced fatty liver. Single irradiation at 0.5 Gy ameliorates ferric nitrilotriacetate-induced nephritis. The irradiation increases catalase and decreases superoxide dismutase in kidney. The result suggests that low dose radiation reduced generation of hydroxide radical generation by reducing cellular hydroperoxide level. Single irradiation at 0.5 Gy at 12 week of age ameliorates incidence of type I diabetes in non-obese diabetic (NOD) mice through the suppression of inflammatory activity of splenocytes, and resultant apoptosis of β-cells in pancreas. The irradiation activities of superoxide dismutase and catalase, which coordinately diminish intracellular reactive oxygen species. Continuous irradiation at 0.70 mGy/hr from 10 week of age elongates life span, and suppresses alopecia in type II diabetesmice. The irradiation improved glucose clearance without affecting insulin-resistance, and increased pancreatic catalase activity. The results suggest that continuous low dose-rate irradiation protect

Perinatal dioxin exposure and the neurodevelopment of Vietnamese toddlers at 1 year of age.

Science.gov (United States)

Pham, Tai The; Nishijo, Muneko; Nguyen, Anh Thi Nguyet; Tran, Nghi Ngoc; Hoang, Luong Van; Tran, Anh Hai; Nguyen, Trung Viet; Nishijo, Hisao

2015-12-01

Dioxin concentrations remain elevated in both the environment and in humans residing near former US Air Force bases in South Vietnam. This may potentially have adverse health effects, particularly on infant neurodevelopment. We followed 214 infants whose mothers resided in a dioxin-contaminated area in Da Nang, Vietnam, from birth until 1 year of age. Perinatal exposure to dioxins was estimated from toxic equivalent (TEQ) levels of polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDDs/Fs-TEQ), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TetraCDD) concentrations in breast milk. In infants, daily dioxin intake (DDI) was used as an index of postnatal exposure through breastfeeding. Neurodevelopment of toddlers was assessed using the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III). No significant differences in neurodevelopmental scores were exhibited for cognitive, language or motor functions between four exposure groups of PCDDs/Fs-TEQ or 2,3,7,8-TetraCDD. However, social-emotional scores were decreased in the high PCDDs/Fs-TEQ group and the high 2,3,7,8-TetraCDD group compared with those with mild exposure, after adjusting for confounding factors. Cognitive scores in the mild, moderate, and high DDI groups were significantly higher than those in low DDI group, but there were no differences in cognitive scores among the three higher DDI groups. These results suggest that perinatal exposure to dioxins may affect social-emotional development of 1-year-old toddlers, without diminishing global neurodevelopmental function. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Polybrominated, polychlorinated and monobromo-polychlorinated dibenzo-p-dioxins/dibenzofurans and dioxin-like polychlorinated biphenyls in marine surface sediments from Hong Kong and Korea

International Nuclear Information System (INIS)

Terauchi, Hidenori; Takahashi, Shin; Lam, Paul K.S.; Min, Byung-Yoon; Tanabe, Shinsuke

2009-01-01

In this study we investigated occurrences and distribution patterns of dioxin-related compounds (DRCs) such as polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs), polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), monobromo-polychlorinated dibenzo-p-dioxins/dibenzofurans (MoBPCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in marine surface sediments collected from the coastal waters of Hong Kong and Korea. In most sampling sites, concentrations of PCDDs were the highest, followed by DL-PCBs, PCDFs, PBDFs, PBDDs, MoBPCDDs and MoBPCDFs in this order. Levels of PBDD/Fs were generally 1-2 orders of magnitude lower than chlorinated analogues. Levels of PCDDs are higher than PCDFs in Hong Kong while levels of PBDFs are higher than PBDDs in Korea (p < 0.05). Report of PBDD/Fs and MoBPCDD/Fs in sediments from East Asian countries is novel and original. Environmental levels of PBDD/Fs are supposed to start increasing in accordance with rising production, use and disposal of brominated flame retardants (BFRs) and recycling processes of e-waste in Asian developing countries. - Brominated and mixed halogenated dioxins/furans in Hong Kong and Korean waters are emitted from industrial activities

Blood levels of dioxins, furans, dioxin-like PCBs, and TEQs in general populations: a review, 1989-2010.

Science.gov (United States)

Consonni, Dario; Sindaco, Raffaella; Bertazzi, Pier Alberto

2012-09-01

A comprehensive worldwide literature review of blood levels of dioxins and dioxin-like compounds in non-exposed adult general populations was performed. The studies published in 1989-2010 reporting information on polychlorinated dibenzo-para-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho-PCBs (nPCBs), mono-ortho-PCBs (mPCBs) levels and Toxic Equivalencies (TEQs, a summary weighted measure of their combined toxicity) were reviewed. TEQs were calculated using as standard the most recent WHO 2005 reevaluation of Toxic Equivalency Factors (TEFs). Weighted multiple regression analyses adjusted for year, subject's age, type of sample analyzed, method used for values below detection limit, and central tendency measure used were performed for each congener and standardized TEQs (log-transformed). We identified 187 studies regarding 29,687 subjects of 26 countries. Year of blood collection ranged from 1985 to 2008. The studies reporting congener levels 161. In adjusted analyses, European countries showed higher levels of most dioxin-like congeners and TEQs. A strong positive association of subjects' age with most congeners and with TEQ values was found, confirming previous findings. Significant decreases over time (1985-2008) were documented for PCCDs, PCDFs, and TEQs including their contributions. No significant decrease was found for non-ortho-PCBs, notably PCB 126. Only some mono-ortho-PCBs showed clear significant declines. Accordingly, TEQs including only PCB contribution did not decrease over time. In interpreting these findings, it should be considered that for dioxin-like PCBs the analysis period was shorter (17 years), since these compounds were first measured in 1992. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Need and Potential of Biosensors to Detect Dioxins and Dioxin-Like Polychlorinated Biphenyls along the Milk, Eggs and Meat Food Chain

Directory of Open Access Journals (Sweden)

Aize Kijlstra

2011-12-01

Full Text Available Dioxins and dioxin-like polychlorinated biphenyls (DL-PCBs are hazardous toxic, ubiquitous and persistent chemical compounds, which can enter the food chain and accumulate up to higher trophic levels. Their determination requires sophisticated methods, expensive facilities and instruments, well-trained personnel and expensive chemical reagents. Ideally, real-time monitoring using rapid detection methods should be applied to detect possible contamination along the food chain in order to prevent human exposure. Sensor technology may be promising in this respect. This review gives the state of the art for detecting possible contamination with dioxins and DL-PCBs along the food chain of animal-source foods. The main detection methods applied (i.e., high resolution gas-chromatography combined with high resolution mass-spectrometry (HRGC/HRMS and the chemical activated luciferase gene expression method (CALUX bioassay, each have their limitations. Biosensors for detecting dioxins and related compounds, although still under development, show potential to overcome these limitations. Immunosensors and biomimetic-based biosensors potentially offer increased selectivity and sensitivity for dioxin and DL-PCB detection, while whole cell-based biosensors present interpretable biological results. The main shortcoming of current biosensors, however, is their detection level: this may be insufficient as limits for dioxins and DL-PCBs for food and feedstuffs are in pg per gram level. In addition, these contaminants are normally present in fat, a difficult matrix for biosensor detection. Therefore, simple and efficient extraction and clean-up procedures are required which may enable biosensors to detect dioxins and DL-PCBs contamination along the food chain.

The Need and Potential of Biosensors to Detect Dioxins and Dioxin-Like Polychlorinated Biphenyls along the Milk, Eggs and Meat Food Chain

Science.gov (United States)

Chobtang, Jeerasak; de Boer, Imke J. M.; Hoogenboom, Ron L. A. P.; Haasnoot, Willem; Kijlstra, Aize; Meerburg, Bastiaan G.

2011-01-01

Dioxins and dioxin-like polychlorinated biphenyls (DL-PCBs) are hazardous toxic, ubiquitous and persistent chemical compounds, which can enter the food chain and accumulate up to higher trophic levels. Their determination requires sophisticated methods, expensive facilities and instruments, well-trained personnel and expensive chemical reagents. Ideally, real-time monitoring using rapid detection methods should be applied to detect possible contamination along the food chain in order to prevent human exposure. Sensor technology may be promising in this respect. This review gives the state of the art for detecting possible contamination with dioxins and DL-PCBs along the food chain of animal-source foods. The main detection methods applied (i.e., high resolution gas-chromatography combined with high resolution mass-spectrometry (HRGC/HRMS) and the chemical activated luciferase gene expression method (CALUX bioassay)), each have their limitations. Biosensors for detecting dioxins and related compounds, although still under development, show potential to overcome these limitations. Immunosensors and biomimetic-based biosensors potentially offer increased selectivity and sensitivity for dioxin and DL-PCB detection, while whole cell-based biosensors present interpretable biological results. The main shortcoming of current biosensors, however, is their detection level: this may be insufficient as limits for dioxins and DL-PCBs for food and feedstuffs are in pg per gram level. In addition, these contaminants are normally present in fat, a difficult matrix for biosensor detection. Therefore, simple and efficient extraction and clean-up procedures are required which may enable biosensors to detect dioxins and DL-PCBs contamination along the food chain. PMID:22247688

The need and potential of biosensors to detect dioxins and dioxin-like polychlorinated biphenyls along the milk, eggs and meat food chain.

Science.gov (United States)

Chobtang, Jeerasak; de Boer, Imke J M; Hoogenboom, Ron L A P; Haasnoot, Willem; Kijlstra, Aize; Meerburg, Bastiaan G

2011-01-01

Dioxins and dioxin-like polychlorinated biphenyls (DL-PCBs) are hazardous toxic, ubiquitous and persistent chemical compounds, which can enter the food chain and accumulate up to higher trophic levels. Their determination requires sophisticated methods, expensive facilities and instruments, well-trained personnel and expensive chemical reagents. Ideally, real-time monitoring using rapid detection methods should be applied to detect possible contamination along the food chain in order to prevent human exposure. Sensor technology may be promising in this respect. This review gives the state of the art for detecting possible contamination with dioxins and DL-PCBs along the food chain of animal-source foods. The main detection methods applied (i.e., high resolution gas-chromatography combined with high resolution mass-spectrometry (HRGC/HRMS) and the chemical activated luciferase gene expression method (CALUX bioassay)), each have their limitations. Biosensors for detecting dioxins and related compounds, although still under development, show potential to overcome these limitations. Immunosensors and biomimetic-based biosensors potentially offer increased selectivity and sensitivity for dioxin and DL-PCB detection, while whole cell-based biosensors present interpretable biological results. The main shortcoming of current biosensors, however, is their detection level: this may be insufficient as limits for dioxins and DL-PCBs for food and feedstuffs are in pg per gram level. In addition, these contaminants are normally present in fat, a difficult matrix for biosensor detection. Therefore, simple and efficient extraction and clean-up procedures are required which may enable biosensors to detect dioxins and DL-PCBs contamination along the food chain.

DIOXINS AND ENDOMETRIOSIS: COHORT STUDY OF WOMEN IN WEST VIRGINIA

Science.gov (United States)

Kanawha Valley of West Virginia has a history of 2,3,7,8-tetrachlorodibenzo-p-dioxin contamination (dioxin, TCDD). The bulk of the dioxin found in this area appears to be derived from the production of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and the disposal of associated wa...

Low Dose Suppression of Neoplastic Transformation in Vitro

Energy Technology Data Exchange (ETDEWEB)

John Leslie Redpath

2012-05-01

This grant was to study the low dose suppression of neoplastic transformation in vitro and the shape of the dose-response curve at low doses and dose-rates of ionizing radiation. Previous findings had indicated a suppression of transformation at dose <10cGy of low-LET radiation when delivered at high dose-rate. The present study indicates that such suppression extends out to doses in excess of 100cGy when the dose (from I-125 photons) is delivered at dose-rates as low as 0.2 mGy/min and out to in excess of {approx}25cGy the highest dose studied at the very low dose-rate of 0.5 mGy/day. We also examined dose-rate effects for high energy protons (which are a low-LET radiation) and suppression was evident below {approx}10cGy for high dose-rate delivery and at least out to 50cGy for low dose-rate (20cGy/h) delivery. Finally, we also examined the effect of low doses of 1 GeV/n iron ions (a high-LET radiation) delivered at high dose-rate on transformation at low doses and found a suppression below {approx}10cGy that could be attributable to an adaptive response in bystander cells induced by the associated low-LET delta rays. These results have implications for cancer risk assessment at low doses.

Dioxins, dioxin-like compounds, and PBDEs in the U.S. domestic meat supply: trends and levels 2003 to 2013

Science.gov (United States)

In the mid-1990s, 2002-2003, 2007-2008, and again in 2012-2013 the U.S. Department of Agriculture (USDA) conducted statistical surveys for dioxin and dioxin-like compound (PCDDs, PCDFs, and PCBs) residues in domestic meat and poultry. The surveys were conducted to determine background levels of diox...

Multidisciplinary European Low Dose Initiative (MELODI). Strategic research agenda for low dose radiation risk research

Energy Technology Data Exchange (ETDEWEB)

Kreuzer, M. [Federal Office for Radiation Protection, BfS, Department of Radiation Protection and Health, Neuherberg (Germany); Auvinen, A. [University of Tampere, Tampere (Finland); STUK, Helsinki (Finland); Cardis, E. [ISGlobal, Barcelona Institute for Global Health, Barcelona (Spain); Durante, M. [Institute for Fundamental Physics and Applications, TIFPA, Trento (Italy); Harms-Ringdahl, M. [Stockholm University, Centre for Radiation Protection Research, Stockholm (Sweden); Jourdain, J.R. [Institute for Radiological Protection and Nuclear Safety, IRSN, Fontenay-aux-roses (France); Madas, B.G. [MTA Centre for Energy Research, Environmental Physics Department, Budapest (Hungary); Ottolenghi, A. [University of Pavia, Physics Department, Pavia (Italy); Pazzaglia, S. [Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Rome (Italy); Prise, K.M. [Queens University Belfast, Belfast (United Kingdom); Quintens, R. [Belgian Nuclear Research Centre, SCK-CEN, Mol (Belgium); Sabatier, L. [French Atomic Energy Commission, CEA, Paris (France); Bouffler, S. [Public Health England, PHE, Chilton (United Kingdom)

2018-03-15

MELODI (Multidisciplinary European Low Dose Initiative) is a European radiation protection research platform with focus on research on health risks after exposure to low-dose ionising radiation. It was founded in 2010 and currently includes 44 members from 18 countries. A major activity of MELODI is the continuous development of a long-term European Strategic Research Agenda (SRA) on low-dose risk for radiation protection. The SRA is intended to identify priorities for national and European radiation protection research programs as a basis for the preparation of competitive calls at the European level. Among those key priorities is the improvement of health risk estimates for exposures close to the dose limits for workers and to reference levels for the population in emergency situations. Another activity of MELODI is to ensure the availability of European key infrastructures for research activities, and the long-term maintenance of competences in radiation research via an integrated European approach for training and education. The MELODI SRA identifies three key research topics in low dose or low dose-rate radiation risk research: (1) dose and dose rate dependence of cancer risk, (2) radiation-induced non-cancer effects and (3) individual radiation sensitivity. The research required to improve the evidence base for each of the three key topics relates to three research lines: (1) research to improve understanding of the mechanisms contributing to radiogenic diseases, (2) epidemiological research to improve health risk evaluation of radiation exposure and (3) research to address the effects and risks associated with internal exposures, differing radiation qualities and inhomogeneous exposures. The full SRA and associated documents can be downloaded from the MELODI website (http://www.melodi-online.eu/sra.html). (orig.)

Risk assessments of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls in food

DEFF Research Database (Denmark)

Larsen, John Christian

2006-01-01

-p-dioxin (TCDD). The toxic responses include dermal toxicity, immunotoxicity, carcinogenicity, and reproductive and developmental toxicity. Toxic equivalency factors have been established for the other PCDD, PCDF and dioxin-like PCB relative to TCDD, and the combined toxicity of a sample can be expressed...... as toxic equivalent (WHO-TEQ). The EC Scientific Committee for Food evaluated these compounds in 2001. The assessment used the most sensitive adverse toxicological end-points of TCDD in experimental animals. These were developmental and reproductive effects in the male offspring of rats administered TCDD......,3,7,8-substituted PCDD and PCDF, and the dioxin-like PCB, and expressed as a group tolerable weekly intake of 14 pg WHC-TEQ/kg bw. The FAO/WHO Joint Expert Committee on Food Additives (JECFA) performed a similar assessment whereas the US Environmental Protection Agency (US EPA) has paid more attention to human data...

Inhibitory mechanism of low-dose, whole-body irradiation with gamma-rays against tumor metastasis

International Nuclear Information System (INIS)

Yasuhiro Ohsima; Mitsutoshi Tukimoto; Shuji Kojima

2007-01-01

Complete text of publication follows. A lot of beneficial effects of low-dose irradiation are well known. Of them, an inhibitory effect of the radiation on lung metastasis is reported so far. It has been reported that low-dose whole-body irradiation with gamma rays enhanced cytotoxic immune response as one of the mechanisms. In our laboratory, it has been confirmed an enhancement of natural killer activity in mice irradiated with whole-body 0.5Gy gamma-rays. Metastasis is accomplished by multistep process, involving basement membrane destruction, local invasion, intravasation, survival in the bloodstream, extravasation into distant organs, and proliferation at the target site. Besides, a lot of growth factors and proteases are involved in these steps. As to mechanism of inhibition of tumor metastasis induced by low-dose whole-body irradiation, studies from the standpoint of tumor invasion have not been reported. Here, inhibitory effect of 0.5Gy whole-body gamma-ray irradiation on tumor metastasis and its mechanism were examined in pulmonary metastasis model mice injected with B16 melanoma cells. Consequently, 0.5Gy whole-body gamma ray irradiation significantly suppressed colony formation in the lungs. Expression of matrix metalloproteinase- 2 (MMP- 2), a proteinase related to metastasis, in lung tissues was suppressed by the radiation. Alteration of tissue inhibitor of matrix metalloproteinase (TIMP) after the gamma-ray irradiation was examined. Expression of TIMP-1 and TIMP-2 mRNA in the lungs were significantly increased. In order to clarify the inhibitory effect obtained in the in vivo metastatic lung cancer model mice, we studied effects of gamma-rays on cell proliferation, alterations of mRNA and proteins related to tumor metastasis in cultured B16 melanoma cells. Proliferation of B16 melanoma cells was decreased in a dose-dependent manner. MMP-2 mRNA expression was not altered in any doses of gamma-rays. Thought expression of the protein was slightly

Low-dose BPA exposure alters the mesenchymal and epithelial transcriptomes of the mouse fetal mammary gland.

Directory of Open Access Journals (Sweden)

Perinaaz R Wadia

Full Text Available Exposure of rodent fetuses to low doses of the endocrine disruptor bisphenol A (BPA causes subtle morphological changes in the prenatal mammary gland and results in pre-cancerous and cancerous lesions during adulthood. To examine whether the BPA-induced morphological alterations of the fetal mouse mammary glands are a associated with changes in mRNA expression reflecting estrogenic actions and/or b dependent on the estrogen receptor α (ERα, we compared the transcriptomal effects of BPA and the steroidal estrogen ethinylestradiol (EE2 on fetal mammary tissues of wild type and ERα knock-out mice. Mammary glands from fetuses of dams exposed to vehicle, 250 ng BPA/kg BW/d or 10 ng EE2/kg BW/d from embryonic day (E 8 were harvested at E19. Transcriptomal analyses on the ductal epithelium and periductal stroma revealed altered expression of genes involved in the focal adhesion and adipogenesis pathways in the BPA-exposed stroma while genes regulating the apoptosis pathway changed their expression in the BPA-exposed epithelium. These changes in gene expression correlated with previously reported histological changes in matrix organization, adipogenesis, and lumen formation resulting in enhanced maturation of the fat-pad and delayed lumen formation in the epithelium of BPA-exposed fetal mammary glands. Overall similarities in the transcriptomal effects of BPA and EE2 were more pronounced in the epithelium, than in the stroma. In addition, the effects of BPA and EE2 on the expression of various genes involved in mammary stromal-epithelial interactions were suppressed in the absence of ERα. These observations support a model whereby BPA and EE2 act directly on the stroma, which expresses ERα, ERβ and GPR30 in fetal mammary glands, and that the stroma, in turn, affects gene expression in the epithelium, where ERα and ERβ are below the level of detection at this stage of development.

The use of the DR CALUX bioassay and indicator polychlorinated biphenyls for screening of elevated levels of dioxins and dioxin-like polychlorinated biphenyls in eel.

NARCIS (Netherlands)

Hoogenboom, Ron; Bovee, Toine; Traag, Win A; Hoogerbrugge, Ronald; Baumann, Bert; Portier, Liza; Weg, Guido van de; Vries, Jaap de

2006-01-01

The DR CALUX bioassay is a very suitable screening method for dioxins and dioxin-like-PCBs in feed and food. This was, e. g. demonstrated in a survey in the Netherlands to control the dioxin levels in eel. The DR CALUX assay, but also indicator polychlorinated biphenyls (PCB) were evaluated as a

Comparison of thermochemically calculated and measured dioxin contents in the off-gas of a sinter plant

Energy Technology Data Exchange (ETDEWEB)

Spencer, P; Eriksson, G; Neuschuelz, D [Lehrstuhl fuer Theoretische Huettenkunde, Aachen (Germany)

1998-12-31

Polychlorinated dibenzo-p-dioxins and dibenzo-furans form a family of more than 200 compounds which are relatively stable in the biosphere and tend to accumulate in the human body. The tetra- to hexa-chlorinated dioxins and furans are considered highly toxic. To facilitate the assessment of the total toxicity of dioxin and furan mixtures, the estimated toxic effects of the individual compounds relative to the 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) were introduced as Toxic Equivalent Factors which yield, when multiplied with the respective concentrations, the Toxic Equivalent (TE) of the mixture. Toxic dioxins and furans are unintentionally formed in a number of industrial combustion processes such as waste incineration and iron ore sintering, in the chemical industry and in household heating. To keep the emissions as low as possible, off-gas clearing systems for the collection of dioxins and furans are increasingly prescribed by the authorities. In addition, it appears desirable to select process conditions that are unfavourable for the formation of these compounds. A simulation of the relevant processes on the basis of thermodynamic data may be helpful in defining such process conditions. To simulate dioxin formation in the sintering process, all major gas-solid reactions taking place in the sinter bed must also be simulated. A sufficiently accurate reproduction of the off-gas compositions along the length of the sinter strand requires detailed assumptions concerning the relative amounts of `active` O{sub 2} as well as the distribution of reacting carbon and water over the strand length. From this basis, an equilibrium calculation for the gas/solid reactions at the sintering temperature of 1150 deg C and an equilibrium calculation restricted to the gas phase at 700 deg C produced values for the concentrations of the major off-gas constituents in very good agreement with the measured values. The further assumption that below 700 deg C all reactions are frozen

Comparison of thermochemically calculated and measured dioxin contents in the off-gas of a sinter plant

Energy Technology Data Exchange (ETDEWEB)

Spencer, P.; Eriksson, G.; Neuschuelz, D. [Lehrstuhl fuer Theoretische Huettenkunde, Aachen (Germany)

1997-12-31

Polychlorinated dibenzo-p-dioxins and dibenzo-furans form a family of more than 200 compounds which are relatively stable in the biosphere and tend to accumulate in the human body. The tetra- to hexa-chlorinated dioxins and furans are considered highly toxic. To facilitate the assessment of the total toxicity of dioxin and furan mixtures, the estimated toxic effects of the individual compounds relative to the 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) were introduced as Toxic Equivalent Factors which yield, when multiplied with the respective concentrations, the Toxic Equivalent (TE) of the mixture. Toxic dioxins and furans are unintentionally formed in a number of industrial combustion processes such as waste incineration and iron ore sintering, in the chemical industry and in household heating. To keep the emissions as low as possible, off-gas clearing systems for the collection of dioxins and furans are increasingly prescribed by the authorities. In addition, it appears desirable to select process conditions that are unfavourable for the formation of these compounds. A simulation of the relevant processes on the basis of thermodynamic data may be helpful in defining such process conditions. To simulate dioxin formation in the sintering process, all major gas-solid reactions taking place in the sinter bed must also be simulated. A sufficiently accurate reproduction of the off-gas compositions along the length of the sinter strand requires detailed assumptions concerning the relative amounts of `active` O{sub 2} as well as the distribution of reacting carbon and water over the strand length. From this basis, an equilibrium calculation for the gas/solid reactions at the sintering temperature of 1150 deg C and an equilibrium calculation restricted to the gas phase at 700 deg C produced values for the concentrations of the major off-gas constituents in very good agreement with the measured values. The further assumption that below 700 deg C all reactions are frozen

Carcinogenesis induced by low-dose radiation

Directory of Open Access Journals (Sweden)

Piotrowski Igor

2017-11-01

Full Text Available Although the effects of high dose radiation on human cells and tissues are relatively well defined, there is no consensus regarding the effects of low and very low radiation doses on the organism. Ionizing radiation has been shown to induce gene mutations and chromosome aberrations which are known to be involved in the process of carcinogenesis. The induction of secondary cancers is a challenging long-term side effect in oncologic patients treated with radiation. Medical sources of radiation like intensity modulated radiotherapy used in cancer treatment and computed tomography used in diagnostics, deliver very low doses of radiation to large volumes of healthy tissue, which might contribute to increased cancer rates in long surviving patients and in the general population. Research shows that because of the phenomena characteristic for low dose radiation the risk of cancer induction from exposure of healthy tissues to low dose radiation can be greater than the risk calculated from linear no-threshold model. Epidemiological data collected from radiation workers and atomic bomb survivors confirms that exposure to low dose radiation can contribute to increased cancer risk and also that the risk might correlate with the age at exposure.

Catalytic Filtration: A proven technology for Dioxin emission control from waste incinerators

International Nuclear Information System (INIS)

Wong, K.T.; Xu, Zhengtian

2010-01-01

Polychlorinated dibenzo-p-dioxins and di benzofurans (PCD/ Fs), in a family of dioxin derivatives with high toxicity, often associated with environmental pollution are the most toxic man made substances, emitted in gas and solid phases during incineration of waste. The threat of dioxin is drawing increasing attention around the world. Governments around the world are phasing in more stringent dioxin emission regulations, and reports about dioxin levels in food products have generated widespread concerns among the public. Issues related to dioxin emissions and disposals are moving up the environmental agenda demanding the most effective and environmentally sound technologies. With heightened public awareness, more stringent regulations, and potential penalties for non-compliance, its more important than ever to avoid the risks associated with inadequate dioxin control. The permissible dioxin emission in most industrial nations is less than 0.1 ng (TEQ)/ Nm 3 and permissible dust emission is from less than 10 to less than 50 mg/ Nm 3 . The common system to remove dioxin is installing an injection process for powdered activated carbon (PAC). This was seen as a proven and widely used technology to control dioxin. This sorbent based system moves dioxin and furan molecules from the gas stream to the solid residue. There are new concerns about existing or future landfill restrictions on the amount and toxicity of sorbent levels in fly ash. Other alternatives are non-flammable additives and catalytic technologies. The non-flammable additives are not proven to control dioxin at temperatures above 200 degree Celsius. Catalytic filter technology can be high initial investment but gaining popularity for operational benefits and reduction of solid residues for landfill. Several criteria are being considered to compare the initial cost of the catalytic filter system and the cost reduction of exhaust gas treatment that can pay for the return of the investment. Field experiences

Biological responses to low dose rate gamma radiation

International Nuclear Information System (INIS)

Magae, Junji; Ogata, Hiromitsu

2003-01-01

Linear non-threshold (LNT) theory is a basic theory for radioprotection. While LNT dose not consider irradiation time or dose-rate, biological responses to radiation are complex processes dependent on irradiation time as well as total dose. Moreover, experimental and epidemiological studies that can evaluate LNT at low dose/low dose-rate are not sufficiently accumulated. Here we analyzed quantitative relationship among dose, dose-rate and irradiation time using chromosomal breakage and proliferation inhibition of human cells as indicators of biological responses. We also acquired quantitative data at low doses that can evaluate adaptability of LNT with statistically sufficient accuracy. Our results demonstrate that biological responses at low dose-rate are remarkably affected by exposure time, and they are dependent on dose-rate rather than total dose in long-term irradiation. We also found that change of biological responses at low dose was not linearly correlated to dose. These results suggest that it is necessary for us to create a new model which sufficiently includes dose-rate effect and correctly fits of actual experimental and epidemiological results to evaluate risk of radiation at low dose/low dose-rate. (author)

Effects of low doses

International Nuclear Information System (INIS)

Le Guen, B.

2001-01-01

Actually, even though it is comfortable for the risk management, the hypothesis of the dose-effect relationship linearity is not confirmed for any model. In particular, in the area of low dose rate delivered by low let emitters. this hypothesis is debated at the light of recent observations, notably these ones relative to the mechanisms leading to genetic instability and induction eventuality of DNA repair. The problem of strong let emitters is still to solve. (N.C.)

The Effects of Low Dose Irradiation on Inflammatory Response Proteins in a 3D Reconstituted Human Skin Tissue Model

Energy Technology Data Exchange (ETDEWEB)

Varnum, Susan M.; Springer, David L.; Chaffee, Mary E.; Lien, Katie A.; Webb-Robertson, Bobbie-Jo M.; Waters, Katrina M.; Sacksteder, Colette A.

2012-12-01

Skin responses to moderate and high doses of ionizing radiation include the induction of DNA repair, apoptosis, and stress response pathways. Additionally, numerous studies indicate that radiation exposure leads to inflammatory responses in skin cells and tissue. However, the inflammatory response of skin tissue to low dose radiation (<10 cGy) is poorly understood. In order to address this, we have utilized a reconstituted human skin tissue model (MatTek EpiDerm FT) and assessed changes in 23 cytokines twenty-four and forty eight hours following treatment of skin with either 3 or 10 cGy low-dose of radiation. Three cytokines, IFN-γ, IL-2, MIP-1α, were significantly altered in response to low dose radiation. In contrast, seven cytokines were significantly altered in response to a high radiation dose of 200 cGy (IL-2, IL-10, IL-13, IFN-γ, MIP-1α, TNF α, and VEGF) or the tumor promoter 12-O-tetradecanoylphorbol 13-acetate (G-CSF, GM-CSF, IL-1α, IL-8, MIP-1α, MIP-1β, RANTES). Additionally, radiation induced inflammation appears to have a distinct cytokine response relative to the non-radiation induced stressor, TPA. Overall, these results indicate that there are subtle changes in the inflammatory protein levels following exposure to low dose radiation and this response is a sub-set of what is seen following a high dose in a human skin tissue model.

Long-term dietary supplementation with low-dose nobiletin ameliorates hepatic steatosis, insulin resistance, and inflammation without altering fat mass in diet-induced obesity.

Science.gov (United States)

Kim, Young-Je; Choi, Myung-Sook; Woo, Je Tae; Jeong, Mi Ji; Kim, Sang Ryong; Jung, Un Ju

2017-08-01

We evaluated the long-term effect of low-dose nobiletin (NOB), a polymethoxylated flavone, on diet-induced obesity and related metabolic disturbances. C57BL/6J mice were fed a high-fat diet (HFD, 45 kcal% fat) with or without NOB (0.02%, w/w) for 16 weeks. NOB did not alter food intake or body weight. Despite increases in fatty acid oxidation-related genes expression and enzymes activity in adipose tissue, NOB did not affect adipose tissue weight due to simultaneous increases in lipogenic genes expression and fatty acid synthase activity. However, NOB significantly decreased not only pro-inflammatory genes expression in adipose tissue but also proinflammatory cytokine levels in plasma. NOB-supplemented mice also showed improved glucose tolerance and insulin resistance, along with decreased levels of plasma insulin, free fatty acids, total cholesterol, non-HDL-cholesterol, and apolipoprotein B. In addition, NOB caused significant decreases in hepatic lipid droplet accumulation and triglyceride content by activating hepatic fatty acid oxidation-related enzymes. Hepatic proinflammatory TNF-α mRNA expression, collagen accumulation, and plasma levels of aminotransferases, liver damage indicators, were also significantly lower in NOB-supplemented mice. These findings suggest that long-term supplementation with low-dose NOB can protect against HFD-induced inflammation, insulin resistance, dyslipidemia, and nonalcoholic fatty liver disease, without ameliorating adiposity. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dose rate effect on low-dose hyper-radiosensitivity with cells in vitro

Energy Technology Data Exchange (ETDEWEB)

Kim, Geon-Min; Kim, Eun-Hee [Seoul National University, Seoul (Korea, Republic of)

2016-10-15

Low-dose hyper-radiosensitivity (HRS) is the phenomenon that mammalian cells exhibit higher sensitivity to radiation at low doses (< 0.5 Gy) than expected by the linear-quadratic model. At doses above 0.5Gy, the cellular response is recovered to the level expected by the linear-quadratic model. This transition is called the increased radio-resistance (IRR). HRS was first verified using Chinese hamster V79 cells in vitro by Marples and has been confirmed in studies with other cell lines including human normal and tumor cells. HRS is known to be induced by inactivation of ataxia telangiectasia-mutated (ATM), which plays a key role in repairing DNA damages. Considering the connection between ATM and HRS, one can infer that dose rate may affect cellular response regarding HRS at low doses. In this study, we quantitated the effect of dose rate on HRS by clonogenic assay with normal and tumor cells. The HRS of cells at low dose exposures is a phenomenon already known. In this study, we observed HRS of rat normal diencephalon cells and rat gliosarcoma cells at doses below 1 Gy. In addition, we found that dose rate mattered. HRS occurred at low doses, but only when total dose was delivered at a rate below certain level.

Mammography-oncogenecity at low doses

International Nuclear Information System (INIS)

Heyes, G J; Mill, A J; Charles, M W

2009-01-01

Controversy exists regarding the biological effectiveness of low energy x-rays used for mammography breast screening. Recent radiobiology studies have provided compelling evidence that these low energy x-rays may be 4.42 ± 2.02 times more effective in causing mutational damage than higher energy x-rays. These data include a study involving in vitro irradiation of a human cell line using a mammography x-ray source and a high energy source which matches the spectrum of radiation observed in survivors from the Hiroshima atomic bomb. Current radiation risk estimates rely heavily on data from the atomic bomb survivors, and a direct comparison between the diagnostic energies used in the UK breast screening programme and those used for risk estimates can now be made. Evidence highlighting the increase in relative biological effectiveness (RBE) of mammography x-rays to a range of x-ray energies implies that the risks of radiation-induced breast cancers for mammography x-rays are potentially underestimated by a factor of four. A pooled analysis of three measurements gives a maximal RBE (for malignant transformation of human cells in vitro) of 4.02 ± 0.72 for 29 kVp (peak accelerating voltage) x-rays compared to high energy electrons and higher energy x-rays. For the majority of women in the UK NHS breast screening programme, it is shown that the benefit safely exceeds the risk of possible cancer induction even when this higher biological effectiveness factor is applied. The risk/benefit analysis, however, implies the need for caution for women screened under the age of 50, and particularly for those with a family history (and therefore a likely genetic susceptibility) of breast cancer. In vitro radiobiological data are generally acquired at high doses, and there are different extrapolation mechanisms to the low doses seen clinically. Recent low dose in vitro data have indicated a potential suppressive effect at very low dose rates and doses. Whilst mammography is a low

75 FR 17857 - Removal of Obsolete References to Herbicides Containing Dioxin

Science.gov (United States)

2010-04-08

... Herbicides Containing Dioxin AGENCY: Department of Veterans Affairs. ACTION: Final rule. SUMMARY: The... health effects of exposure to herbicides containing dioxin and radiation to remove the obsolete references to herbicides containing dioxin. This final rule reflects changes made by the Agent Orange Act of...

Effects of low doses; Effet des faibles doses

Energy Technology Data Exchange (ETDEWEB)

Le Guen, B. [Electricite de France (EDF-LAM-SCAST), 93 - Saint-Denis (France)

2001-07-01

Actually, even though it is comfortable for the risk management, the hypothesis of the dose-effect relationship linearity is not confirmed for any model. In particular, in the area of low dose rate delivered by low let emitters. this hypothesis is debated at the light of recent observations, notably these ones relative to the mechanisms leading to genetic instability and induction eventuality of DNA repair. The problem of strong let emitters is still to solve. (N.C.)

Impacts of Perinatal Dioxin Exposure on Motor Coordination and Higher Cognitive Development in Vietnamese Preschool Children: A Five-Year Follow-Up.

Directory of Open Access Journals (Sweden)

Nghi Ngoc Tran

Full Text Available Dioxin concentrations remain elevated in the environment and in humans residing near former US Air Force bases in South Vietnam. Our previous epidemiological studies showed adverse effects of dioxin exposure on neurodevelopment for the first 3 years of life. Subsequently, we extended the follow-up period and investigated the influence of perinatal dioxin exposure on neurodevelopment, including motor coordination and higher cognitive ability, in preschool children. Presently, we investigated 176 children in a hot spot of dioxin contamination who were followed up from birth until 5 years old. Perinatal dioxin exposure levels were estimated by measuring dioxin levels in maternal breast milk. Dioxin toxicity was evaluated using two indices; toxic equivalent (TEQ-polychlorinated dibenzo-p-dioxins/furans (PCDDs/Fs and concentration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD. Coordinated movements, including manual dexterity, aiming and catching, and balance, were assessed using the Movement Assessment Battery for Children, Second Edition (Movement ABC-2. Cognitive ability was assessed using the nonverbal index (NVI of the Kaufman Assessment Battery for Children, Second Edition (KABC-II. In boys, total test and balance scores of Movement ABC-2 were significantly lower in the high TEQ- PCDDs/Fs group compared with the moderate and low exposure groups. NVI scores and the pattern reasoning subscale of the KABC-II indicating planning ability were also significantly lower in the high TCDD exposure group compared with the low exposure group of boys. However, in girls, no significant differences in Movement ABC-2 and KABC-II scores were found among the different TEQ-PCDDs/Fs and TCDD exposure groups. Furthermore, in high risk cases, five boys and one girl highly exposed to TEQ-PCDDs/Fs and TCDD had double the risk for difficulties in both neurodevelopmental skills. These results suggest differential impacts of TEQ-PCDDs/Fs and TCDD exposure on motor

Impacts of Perinatal Dioxin Exposure on Motor Coordination and Higher Cognitive Development in Vietnamese Preschool Children: A Five-Year Follow-Up.

Science.gov (United States)

Tran, Nghi Ngoc; Pham, Tai The; Ozawa, Kyoko; Nishijo, Muneko; Nguyen, Anh Thi Nguyet; Tran, Tuong Quy; Hoang, Luong Van; Tran, Anh Hai; Phan, Vu Huy Anh; Nakai, Akio; Nishino, Yoshikazu; Nishijo, Hisao

2016-01-01

Dioxin concentrations remain elevated in the environment and in humans residing near former US Air Force bases in South Vietnam. Our previous epidemiological studies showed adverse effects of dioxin exposure on neurodevelopment for the first 3 years of life. Subsequently, we extended the follow-up period and investigated the influence of perinatal dioxin exposure on neurodevelopment, including motor coordination and higher cognitive ability, in preschool children. Presently, we investigated 176 children in a hot spot of dioxin contamination who were followed up from birth until 5 years old. Perinatal dioxin exposure levels were estimated by measuring dioxin levels in maternal breast milk. Dioxin toxicity was evaluated using two indices; toxic equivalent (TEQ)-polychlorinated dibenzo-p-dioxins/furans (PCDDs/Fs) and concentration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Coordinated movements, including manual dexterity, aiming and catching, and balance, were assessed using the Movement Assessment Battery for Children, Second Edition (Movement ABC-2). Cognitive ability was assessed using the nonverbal index (NVI) of the Kaufman Assessment Battery for Children, Second Edition (KABC-II). In boys, total test and balance scores of Movement ABC-2 were significantly lower in the high TEQ- PCDDs/Fs group compared with the moderate and low exposure groups. NVI scores and the pattern reasoning subscale of the KABC-II indicating planning ability were also significantly lower in the high TCDD exposure group compared with the low exposure group of boys. However, in girls, no significant differences in Movement ABC-2 and KABC-II scores were found among the different TEQ-PCDDs/Fs and TCDD exposure groups. Furthermore, in high risk cases, five boys and one girl highly exposed to TEQ-PCDDs/Fs and TCDD had double the risk for difficulties in both neurodevelopmental skills. These results suggest differential impacts of TEQ-PCDDs/Fs and TCDD exposure on motor coordination and

Toxicological profile of ultrapure 2,2',3,4,4',5,5'-heptachlorbiphenyl (PCB 180) in adult rats.

Science.gov (United States)

Viluksela, Matti; Heikkinen, Päivi; van der Ven, Leo T M; Rendel, Filip; Roos, Robert; Esteban, Javier; Korkalainen, Merja; Lensu, Sanna; Miettinen, Hanna M; Savolainen, Kari; Sankari, Satu; Lilienthal, Hellmuth; Adamsson, Annika; Toppari, Jorma; Herlin, Maria; Finnilä, Mikko; Tuukkanen, Juha; Leslie, Heather A; Hamers, Timo; Hamscher, Gerd; Al-Anati, Lauy; Stenius, Ulla; Dervola, Kine-Susann; Bogen, Inger-Lise; Fonnum, Frode; Andersson, Patrik L; Schrenk, Dieter; Halldin, Krister; Håkansson, Helen

2014-01-01

PCB 180 is a persistent non-dioxin-like polychlorinated biphenyl (NDL-PCB) abundantly present in food and the environment. Risk characterization of NDL-PCBs is confounded by the presence of highly potent dioxin-like impurities. We used ultrapure PCB 180 to characterize its toxicity profile in a 28-day repeat dose toxicity study in young adult rats extended to cover endocrine and behavioral effects. Using a loading dose/maintenance dose regimen, groups of 5 males and 5 females were given total doses of 0, 3, 10, 30, 100, 300, 1000 or 1700 mg PCB 180/kg body weight by gavage. Dose-responses were analyzed using benchmark dose modeling based on dose and adipose tissue PCB concentrations. Body weight gain was retarded at 1700 mg/kg during loading dosing, but recovered thereafter. The most sensitive endpoint of toxicity that was used for risk characterization was altered open field behavior in females; i.e. increased activity and distance moved in the inner zone of an open field suggesting altered emotional responses to unfamiliar environment and impaired behavioral inhibition. Other dose-dependent changes included decreased serum thyroid hormones with associated histopathological changes, altered tissue retinoid levels, decreased hematocrit and hemoglobin, decreased follicle stimulating hormone and luteinizing hormone levels in males and increased expression of DNA damage markers in liver of females. Dose-dependent hypertrophy of zona fasciculata cells was observed in adrenals suggesting activation of cortex. There were gender differences in sensitivity and toxicity profiles were partly different in males and females. PCB 180 adipose tissue concentrations were clearly above the general human population levels, but close to the levels in highly exposed populations. The results demonstrate a distinct toxicological profile of PCB 180 with lack of dioxin-like properties required for assignment of WHO toxic equivalency factor. However, PCB 180 shares several toxicological

Dioxins, Furans and PCBs in Recycled Water for Indirect Potable Reuse

Directory of Open Access Journals (Sweden)

Clemencia Rodriguez

2008-12-01

Full Text Available An assessment of potential health impacts of dioxin and dioxin-like compounds in recycled water for indirect potable reuse was conducted. Toxic equivalency factors (TEFs for 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDD and dibenzofurans (PCDFs and dioxin-like polychlorinated biphenyls (PCBs congeners have been developed by the World Health Organization to simplify the risk assessment of complex mixtures. Samples of secondary treated wastewater in Perth, Australia were examined pre-and post-tertiary treatment in one full-scale and one pilot water reclamation plant. Risk quotients (RQs were estimated by expressing the middle-bound toxic equivalent (TEQ and the upper-bound TEQ concentration in each sampling point as a function of the estimated health target value. The results indicate that reverse osmosis (RO is able to reduce the concentration of PCDD, PCDF and dioxin-like PCBs and produce water of high quality (RQ after RO=0.15. No increased human health risk from dioxin and dioxin-like compounds is anticipated if highly treated recycled water is used to augment drinking water supplies in Perth. Recommendations for a verification monitoring program are offered.

Dioxins, Furans and PCBs in Recycled Water for Indirect Potable Reuse

Science.gov (United States)

Rodriguez, Clemencia; Cook, Angus; Devine, Brian; Van Buynder, Paul; Lugg, Richard; Linge, Kathryn; Weinstein, Philip

2008-01-01

An assessment of potential health impacts of dioxin and dioxin-like compounds in recycled water for indirect potable reuse was conducted. Toxic equivalency factors (TEFs) for 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (PCBs) congeners have been developed by the World Health Organization to simplify the risk assessment of complex mixtures. Samples of secondary treated wastewater in Perth, Australia were examined pre-and post-tertiary treatment in one full-scale and one pilot water reclamation plant. Risk quotients (RQs) were estimated by expressing the middle-bound toxic equivalent (TEQ) and the upper-bound TEQ concentration in each sampling point as a function of the estimated health target value. The results indicate that reverse osmosis (RO) is able to reduce the concentration of PCDD, PCDF and dioxin-like PCBs and produce water of high quality (RQ after RO=0.15). No increased human health risk from dioxin and dioxin-like compounds is anticipated if highly treated recycled water is used to augment drinking water supplies in Perth. Recommendations for a verification monitoring program are offered. PMID:19151430

Study on distributions and recoveries of tetrachlorodibenzo-p-dioxin and octachlorodibenzo-p-dioxin in a mm5 sampling train

International Nuclear Information System (INIS)

Finkel, J.M.; James, R.H.; Baughman, K.W.

1990-12-01

14 C-dioxin tracers were used to evaluate whole MM5 sampling train recoveries of dioxin and to determine the distribution of dioxins spiked into a sampling train that was concurrently sampling emissions from a burn of either natural gas ('clean' burn) or kerosene ('dirty' burn). The spike tests were made with a pilot-scale furnace constructed and operated in the laboratory. Recovery of 14 C-dioxin from the MM5 sampling train was determined by scintillation spectrometry. The experimental results indicate that the amount of spiked TCDD- 14 C recovered was approximately 85% during a natural gas test and 83% during a kerosene test. The amount of spiked OCDD- 14 C recovered was approximately 88% during a kerosene test. Also, the data indicate that during the kerosene tests OCDD- 14 C is collected primarily in the front half of the sampling train but TCDD- 14 C is often found in the XAD and the rear filter bell, riser and condenser of the sampling train. During the natural gas tests, TCDD- 14 C was primarily in the XAD. The distribution of the TCDD- 14 C in the kerosene tests was dependent on the rigid operation of the sampling train. The information from the study will be used to determine procedural areas that need improvements or modifications to allow the efficient collection and accurate determination of trace levels of dioxins and furans using the MM5 Method

Non-linear dose-response of aluminium hydroxide adjuvant particles: Selective low dose neurotoxicity

International Nuclear Information System (INIS)

Crépeaux, Guillemette; Eidi, Housam; David, Marie-Odile; Baba-Amer, Yasmine; Tzavara, Eleni; Giros, Bruno; Authier, François-Jérôme; Exley, Christopher; Shaw, Christopher A.; Cadusseau, Josette

2017-01-01

Aluminium (Al) oxyhydroxide (Alhydrogel ® ), the main adjuvant licensed for human and animal vaccines, consists of primary nanoparticles that spontaneously agglomerate. Concerns about its safety emerged following recognition of its unexpectedly long-lasting biopersistence within immune cells in some individuals, and reports of chronic fatigue syndrome, cognitive dysfunction, myalgia, dysautonomia and autoimmune/inflammatory features temporally linked to multiple Al-containing vaccine administrations. Mouse experiments have documented its capture and slow transportation by monocyte-lineage cells from the injected muscle to lymphoid organs and eventually the brain. The present study aimed at evaluating mouse brain function and Al concentration 180 days after injection of various doses of Alhydrogel ® (200, 400 and 800 μg Al/kg of body weight) in the tibialis anterior muscle in adult female CD1 mice. Cognitive and motor performances were assessed by 8 validated tests, microglial activation by Iba-1 immunohistochemistry, and Al level by graphite furnace atomic absorption spectroscopy. An unusual neuro-toxicological pattern limited to a low dose of Alhydrogel ® was observed. Neurobehavioural changes, including decreased activity levels and altered anxiety-like behaviour, were observed compared to controls in animals exposed to 200 μg Al/kg but not at 400 and 800 μg Al/kg. Consistently, microglial number appeared increased in the ventral forebrain of the 200 μg Al/kg group. Cerebral Al levels were selectively increased in animals exposed to the lowest dose, while muscle granulomas had almost Completely disappeared at 6 months in these animals. We conclude that Alhydrogel ® injected at low dose in mouse muscle may selectively induce long-term Al cerebral accumulation and neurotoxic effects. To explain this unexpected result, an avenue that could be explored in the future relates to the adjuvant size since the injected suspensions corresponding to the lowest dose

Dioxin emissions into the air in the Netherlands

NARCIS (Netherlands)

Koning, J. de

1996-01-01

In 1989 in The Netherlands elevated dioxin concentrations were found in cow's milk originating from areas a.o. located near Municipal Solid Waste Combustion (MSWC) facilities. This induced the Dutch government to set up an extensive programme for making an inventory of all possible dioxin sources in

Low-dose computed tomography image restoration using previous normal-dose scan

International Nuclear Information System (INIS)

Ma, Jianhua; Huang, Jing; Feng, Qianjin; Zhang, Hua; Lu, Hongbing; Liang, Zhengrong; Chen, Wufan

2011-01-01

Purpose: In current computed tomography (CT) examinations, the associated x-ray radiation dose is of a significant concern to patients and operators. A simple and cost-effective means to perform the examinations is to lower the milliampere-seconds (mAs) or kVp parameter (or delivering less x-ray energy to the body) as low as reasonably achievable in data acquisition. However, lowering the mAs parameter will unavoidably increase data noise and the noise would propagate into the CT image if no adequate noise control is applied during image reconstruction. Since a normal-dose high diagnostic CT image scanned previously may be available in some clinical applications, such as CT perfusion imaging and CT angiography (CTA), this paper presents an innovative way to utilize the normal-dose scan as a priori information to induce signal restoration of the current low-dose CT image series. Methods: Unlike conventional local operations on neighboring image voxels, nonlocal means (NLM) algorithm utilizes the redundancy of information across the whole image. This paper adapts the NLM to utilize the redundancy of information in the previous normal-dose scan and further exploits ways to optimize the nonlocal weights for low-dose image restoration in the NLM framework. The resulting algorithm is called the previous normal-dose scan induced nonlocal means (ndiNLM). Because of the optimized nature of nonlocal weights calculation, the ndiNLM algorithm does not depend heavily on image registration between the current low-dose and the previous normal-dose CT scans. Furthermore, the smoothing parameter involved in the ndiNLM algorithm can be adaptively estimated based on the image noise relationship between the current low-dose and the previous normal-dose scanning protocols. Results: Qualitative and quantitative evaluations were carried out on a physical phantom as well as clinical abdominal and brain perfusion CT scans in terms of accuracy and resolution properties. The gain by the use

The need and Potential of Biosensors to Detect Dioxins and Dioxin-Like Polychlorinated Biphenyls along the Milk, Eggs and Meat Food Chain

NARCIS (Netherlands)

Chobtang, J.; Boer, de I.J.M.; Hoogenboom, L.A.P.; Haasnoot, W.; Kijlstra, A.; Meerburg, B.G.

2011-01-01

Dioxins and dioxin-like polychlorinated biphenyls (DL-PCBs) are hazardous toxic, ubiquitous and persistent chemical compounds, which can enter the food chain and accumulate up to higher trophic levels. Their determination requires sophisticated methods, expensive facilities and instruments,

Plants as warning signal for exposure to low dose radiation

International Nuclear Information System (INIS)

Rusli Ibrahim; Norhafiz Talib

2012-01-01

carries the advantage of observing meaningful data in a short period of time, being able to meditate effects on human health and to prevent possible accidents, when adopted as periodical monitoring. Tradescantia Pallida Purpurea can be regarded as a biosensor plant or a biological warning signal for exposure to low dose radiation which exhibits a noticeable quantity of cell alteration in a short time following exposure to radiation. Hence, the effects caused on the environment might be anticipated, and by extension on the human being, as a result of its occupation exposition level. The use of this method can be recommended for radiation monitoring, therefore into the environment acclimatization, and may be used, in addition, in the prevention of radiological accidents. (author)

A baseline study on levels of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, non-ortho and mono-ortho PCBs, non-dioxin-like PCBs and polybrominated diphenyl ethers in Northeast Arctic cod (Gadus morhua) from different parts of the Barents Sea

International Nuclear Information System (INIS)

Julshamn, Kaare; Duinker, Arne; Berntssen, Marc; Nilsen, Bente M.; Frantzen, Sylvia; Nedreaas, Kjell; Maage, Amund

2013-01-01

Highlights: • Livers of cod from the Barents Sea have been analysed for dioxins, PCBs and PBDEs. • The overall mean concentration of dioxins and DL-PCBs was 14.2 ng TEQ WHO-2005 /kg ww. • The concentrations of dioxins and DL-PCBs varied between 1.0 and 151 ng TEQ/kg ww. • 20% of the samples had concentrations higher than 20 ng TEQ/kg ww. • The highest concentrations of dioxins and PCB were found in samples from the east area of the Barents Sea. -- Abstract: This study is one of several baseline studies on commercially important Norwegian wild fish species that will provide information concerning metals and persistent organic pollutants (POPs) and food safety. The cod liver is a traditional food product in Norway and a potential source for POPs in the diet. The concentrations of dioxins and furans (PCDD/Fs), dioxin-like PCBs (DL-PCBs), non-dioxin-like PCBs (NDL-PCBs, PCB 6 ) and polybrominated flame retardants (PBDEs) were determined in the liver of 784 individual Northeast Arctic cod caught at 32 positions in the Barents Sea in the period from 2009–2010. In addition, muscle samples from 30 individual cod were analysed for the same substances. The mean concentration of the sum of PCDD/Fs and DL-PCBs for all samples was 14.2 ng TEQ who-2005 /kg ww with a variation between 1.0 and 151 ng TEQ/kg ww. The concentrations of POPs in the fillet samples were very low

In Utero Exposure to Compounds with Dioxin-like Activity and Birth Outcomes

DEFF Research Database (Denmark)

Vafeiadi, Marina; Agramunt, Silvia; Pedersen, Marie

2014-01-01

BACKGROUND: Maternal exposure to dioxins and dioxin-like compounds may affect fetal growth and development. We evaluated the association between in utero dioxin-like activity and birth outcomes in a prospective European mother-child study. METHODS: We measured dioxin-like activity in maternal...... and cord blood plasma samples collected at delivery using the Dioxin-Responsive Chemically Activated LUciferase eXpression (DR CALUX) bioassay in 967 mother-child pairs, in Denmark, Greece, Norway, Spain, and England. Multiple linear regression models were used to investigate the associations with birth...... weight, gestational age, and head circumference. RESULTS: Plasma dioxin-like activity was higher in maternal sample than in cord samples. Birth weight was lower with medium (-58 g [95% confidence interval (CI) = -176 to 62]) and high (-82 g [-216 to 53]) tertiles of exposure (cord blood) compared...

Evaluation of the release of dioxins and PCBs during kiln-firing of ball clay.

Science.gov (United States)

Broadwater, Kendra; Meeker, John D; Luksemburg, William; Maier, Martha; Garabrant, David; Demond, Avery; Franzblau, Alfred

2014-01-01

Ball clay is known to be naturally contaminated with high levels of polychlorinated di-benzo-p-dioxins (PCDDs). This study evaluated the potential for PCDD, polychlorinated dibenzofuran (PCDF) and polychlorinated biphenyl (PCB) release during the kiln firing of ball clay in an art studio. Toxic equivalence (TEQ) were calculated using World Health Organization (WHO) 2005 toxic equivalence factors (TEF) and congener concentrations. Ten bags of commercial ball clay were found to have an average TEQ of 1,370 nanograms/kilogram (ng kg(-1)) dry weight (dw), almost exclusively due to PCDDs (99.98% of TEQ). After firing, none of the 29 dioxin-like analytes was measured above the limits of detection (LOD) in the clay samples. Air samples were taken during firings using both low-flow and high-flow air samplers. Few low-flow air samples contained measurable levels of dioxin congeners above the LOD. The mean TEQ in the high volume air samples ranged from 0.07 pg m(-3) to 0.21 pg m(-3) when firing ball clay, and was 0.11 pg m(-3) when no clay was fired. These concentrations are within the range measured in typical residences and well-controlled industrial settings. The congener profiles in the high-flow air samples differed from the unfired clay; the air samples had a considerable contribution to the TEQ from PCDFs and PCBs. Given that the TEQs of all air samples were very low and the profiles differed from the unfired clay, it is likely that the PCDDs in dry ball clay were destroyed during kiln firing. These results suggest that inhalation of volatilized dioxins during kiln firing of dry ball clay is an unlikely source of exposure for vocational and art ceramicists. Copyright © 2013 Elsevier Ltd. All rights reserved.

Toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on the peripheral nervous system of developing red seabream (Pagrus major)

Energy Technology Data Exchange (ETDEWEB)

Iida, Midori [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Kim, Eun-Young [Department of Life and Nanopharmaceutical Science and Department of Biology, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Murakami, Yasunori [Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Shima, Yasuhiro [National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, Imabari 794-2305 (Japan); Iwata, Hisato, E-mail: iwatah@agr.ehime-u.ac.jp [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan)

2013-03-15

We investigated 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced effects on the morphology of peripheral nervous system (PNS) in the developing red seabream (Pagrus major) embryos. The embryos at 10 h post-fertilization (hpf) were treated with 0, 0.1, 0.4 or 1.7 μg/L of TCDD in seawater for 80 min. The morphology of PNS was microscopically observed with florescence staining using an anti-acetylated tubulin antibody at 48, 78, 120 and 136 hpf. Axon length of facial nerve (VII) was found to be shortened by TCDD exposure. Axon guidance in the glossopharyngeal nerve (IX) and vagus nerve (X) was altered at 120 and 136 hpf in a TCDD dose-dependent manner. Lowest observable effect level of TCDD (0.1 μg/L) that induced the morphological alteration of PNS was lower than those of other endpoints on morphological deformities so far reported. Given that the growth cone at the tip of growing nerve axons advances under the influence of its surrounding tissues, we hypothesized that TCDD exposure would affect (1) the nerve cell proliferation/differentiation, (2) the structure of muscle as an axon target and (3) the nerve guidance factor in the embryos. By the immunostaining of embryos with an antibody against the neuronal specific RNA-binding protein, HuD, and an antibody against the sarcomeric myosin, no morphological effects were observed on the neural proliferation/differentiation and the structure of facial muscles of TCDD-treated embryos. In contrast, whole mount in situ hybridization of semaphorin 3A (Sema3A), a secretory axon repulsion factor, revealed the altered expression pattern of its transcripts in TCDD-treated embryos. Our findings suggest that TCDD treatment affects the projection of PNS in the developing red seabream embryos through the effects on the axonal growth cone guidance molecule such as Sema3A, but not on the neuronal differentiation/proliferation and axon target. The PNS in developing embryos may be one of the most sensitive biomarkers to the exposure

Radon Exposure and the Definition of Low Doses-The Problem of Spatial Dose Distribution.

Science.gov (United States)

Madas, Balázs G

2016-07-01

Investigating the health effects of low doses of ionizing radiation is considered to be one of the most important fields in radiological protection research. Although the definition of low dose given by a dose range seems to be clear, it leaves some open questions. For example, the time frame and the target volume in which absorbed dose is measured have to be defined. While dose rate is considered in the current system of radiological protection, the same cancer risk is associated with all exposures, resulting in a given amount of energy absorbed by a single target cell or distributed among all the target cells of a given organ. However, the biological effects and so the health consequences of these extreme exposure scenarios are unlikely to be the same. Due to the heterogeneous deposition of radon progeny within the lungs, heterogeneous radiation exposure becomes a practical issue in radiological protection. While the macroscopic dose is still within the low dose range, local tissue doses on the order of Grays can be reached in the most exposed parts of the bronchial airways. It can be concluded that progress in low dose research needs not only low dose but also high dose experiments where small parts of a biological sample receive doses on the order of Grays, while the average dose over the whole sample remains low. A narrow interpretation of low dose research might exclude investigations with high relevance to radiological protection. Therefore, studies important to radiological protection should be performed in the frame of low dose research even if the applied doses do not fit in the dose range used for the definition of low doses.

Are low radiation doses Dangerous?

International Nuclear Information System (INIS)

Garcia Lima, O.; Cornejo, N.

1996-01-01

In the last few years the answers to this questions has been affirmative as well as negative from a radiation protection point of view low doses of ionizing radiation potentially constitute an agent causing stochasting effects. A lineal relation without threshold is assumed between dose and probability of occurrence of these effects . Arguments against the danger of probability of occurrence of these effects. Arguments again the danger of low dose radiation are reflected in concepts such as Hormesis and adaptive response, which are phenomena that being studied at present

Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on adipogenic differentiation and insulin-induced glucose uptake in 3T3-L1 cells

International Nuclear Information System (INIS)

Hsu, Hsin-Fen; Tsou, Tsui-Chun; Chao, How-Ran; Kuo, Ya-Ting; Tsai, Feng-Yuan; Yeh, Szu-Ching

2010-01-01

Dioxin exposure has been positively associated with human type II diabetes. Because lipophilic dioxins accumulate mainly in adipose tissue, this study aimed to determine if dioxins induce metabolic dysfunction in fat cells. Using 3T3-L1 cells as an in vitro model, we analyzed the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a model dioxin, on adipogenic differentiation, glucose uptake, and lipolysis. TCDD inhibited adipogenic differentiation, as determined by using oil droplet formation and adipogenic marker gene expression, including PPARγ (peroxisome proliferator-activated receptor γ), C/EBPα (CCAAT/enhancer-binding protein α), and Glut4 (glucose transporter type 4). Effects of TCDD on glucose uptake were evaluated using fully differentiated 3T3-L1 adipocytes, revealing that TCDD significantly attenuated insulin-induced glucose uptake dose dependently. Inhibition of aryl hydrocarbon receptor (AhR) by α-naphthoflavone (α-NF), an AhR inhibitor, did not prevent the inhibitory effect of TCDD on glucose uptake, suggesting that TCDD attenuates insulin-induced glucose uptake in an AhR-independent manner. Effects of TCDD on lipolysis were determined using glycerol release assay. We found that TCDD had no marked effect on isoproterenol-induced glycerol release in fully differentiated 3T3-L1 adipocytes. These results provide in vitro evidence of TCDD's effects on fat cell metabolism, suggesting dioxin exposure in development of insulin resistance and type II diabetes.

Dioxins and Nonortho PCBs in Breast Milk of Vietnamese Mothers Living in the Largest Hot Spot of Dioxin Contamination.

Science.gov (United States)

Nghi, Tran Ngoc; Nishijo, Muneko; Manh, Ho Dung; Tai, Pham The; Van Luong, Hoang; Anh, Tran Hai; Thao, Pham Ngoc; Trung, Nguyen Viet; Waseda, Tomoo; Nakagawa, Hideaki; Kido, Teruhiko; Nishijo, Hisao

2015-05-05

Bien Hoa Air Base is the largest dioxin contamination hot spot in Vietnam. In 2012, we recruited 216 mothers who were living in 10 communities around Bien Hoa Air Base and had delivered newborns at a prefecture hospital, and we investigated recent exposure levels of dioxins and nonortho PCBs in their breast milk. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (2,3,7,8-tetraCDD) was present at 2.6 pg/g lipid in primiparae and 2.2 pg/g lipid in multiparae. Among multiparae and total subjects, significant high prevalence of 2,3,7,8-tetraCDD≥5 pg/g lipid and 2,3,7,8-tetraCDD contribution≥40% were observed in mothers living in the five communities closest to Bien Hoa Air Base. The TEQ for nonortho PCBs was 1.6 pg-TEQ/g lipid for primiparae, and this was even lower than that in the unsprayed area. The length of residency was a strong factor to increase dioxins, including 2,3,7,8-tetraCDD. Residency in the five communities with the highest exposure was a specific risk factor for increased 2,3,7,8-tetraCDD in breast milk. Food intake might contribute partly to the increased levels of dioxin congeners other than 2,3,7,8-tetraCDD in breast milk. These results suggest that Bien Hoa Air Base has led to elevated 2,3,7,8-tetraCDD levels in breast milk of mothers in nearby areas even in the recent years.

COHORT OF WOMEN LIVING IN OR NEAR A HIGHLY INDUSTRIALIZED AREA OF KANAWHA RIVER VALLEY IN WEST VIRGINIA: ENDOMETRIOSIS AND BLOOD LEVELS OF DIOXIN AND DIOXIN-LIKE CHEMICALS

Science.gov (United States)

Introduction Historical releases of dioxin and dioxin-like chemicals with subsequent impacts to environmental media in the Kanawha River Valley (KRV) of West Virginia have been well documented.' The bulk of dioxin found in this area appears to be derived from the production of 2,...

Determination of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls in human serum using programmable-temperature vaporization gas chromatography with high-resolution mass spectrometry.

Science.gov (United States)

Zhang, Lei; Zhong, Yuxin; Liu, Xin; Bao, Yan; Zhao, Yunfeng; Wu, Yongning; Cai, Zongwei; Li, Jingguang

2017-09-01

The determination of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls in blood from a non-occupational population is essential for the investigation of adverse health effects from these pollutants. In this study, a sensitive method based on programmable-temperature vaporization with large-volume injection coupled with gas chromatography with high-resolution mass spectrometry was developed to determine these pollutants in 1-2 mL of human serum samples. Various key parameters of programmable-temperature vaporization injector, including vent temperature, vent time, vent flow, transfer temperature and transfer time were optimized by factorial design. The accuracy and precision as well as applicability were assessed by determining polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls in calibration standard solutions, standard reference materials and real human serum samples from non-occupational population. The method detection limits of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls were 1.5-9.0 and 0.005-0.02 ng/kg wet weight, respectively. By comparing with typically splitless injection, the application of programmable-temperature vaporization injector could effectively lead to higher detectable rate of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls in 1-2 mL of human serum samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Levels, profiles and risk assessment of polychlorinated biphenyls, dibenzo-p-dioxins and dibenzofurans in breast milk from North China

Energy Technology Data Exchange (ETDEWEB)

Zhao, J.H.; Sun, S.J.; Horiguchi, H.; Kayama, F. [Dept. of Environ. Medicine, Jichi Medical School, Kawachi-gun (Japan)]|[CREST-JST, Kawaguchi, Saitama (Japan); Nakamura, M. [Hiyoshi Corp., Omihachiman, Shiga (Japan); Li Li; Ge Jun [Hospital of gynaecology and maternity of Shijiazhuang, Hebei Province (China); Ma Yu-Xia [Dept. of Hygienic Food, Collection of Public Health, Hebei Medical Univ. (China); Hou Xiu-Jun [The Second Hospital of Luanxian, Hebei Province (China); Clark, G. [Xenobiotic Detection System International Inc., Durham, NC (United States)

2004-09-15

China have produced and used organochlorine pesticides with low purity in a large quantity. However, there is little information on the environmental levels of organohalogens contamination as well as body burden of these chemicals, especially in Mainland China. After recent rapid growth of economy in China, health effects of persistent organohalogens are of growing concern. To assess mother's body burden and perinatal exposure of dioxins and pesticides, we collected breast milk specimens from Shijiazhuang urban and Tangshan rural area, Hebei Province, North China, and measured dioxins by DIPS-CALUX{sup circledR} bioassay (Dioxin and PCB specific Chemical-Activated LUciferase gene eXpression cell bioassay system).

Fast Sampling and Analysis of Offgas Dioxins/Furans Using a Thermal Desorption-Gas Chromatography-High Resolution Mass Spectrometry Method

International Nuclear Information System (INIS)

Whitworth, C. G.; Rees, R. T.; Reick, K. G.; Montgomery, J. L.; Battleson, D. M.; LeFever, J.; Sears, L. J.

2002-01-01

The United States Department of Energy is using or evaluating several Alternatives-to- Incineration (ATI) technologies for treating hazardous wastes and low-level mixed wastes. ATI treatment technologies may have the potential for generating gaseous or other emissions of polychlorinated dioxins/furans, a class of highly toxic compounds which are regulated to very low levels. At present, the emission limit for dioxins/furans from hazardous waste incinerators is 0.2 ng TEQ/dscm (0.4 ng TEQ/dscm w/TC). Emissions from ATI technologies are expected to be subject to similar restrictions

First results from dioxins and dioxin-like compounds in the population from Madeira Island, Portugal. Part 1. Biomonitoring in blood of the general population living near to a solid waste incinerator

Energy Technology Data Exchange (ETDEWEB)

M. Fatima Reis; J. Pereira Miguel; Sampaio, C. [Inst. of Preventive Medicine, Lisbon (Portugal); J. Mauricio Melim [Public Health Regional Dept., Funchal (Portugal); Aguiar, P. [National School of Public Health, Lisbon (Portugal)

2004-09-15

The present study is one of a series of papers describing selected results of the ongoing projects, designed to ultimately evaluate the potential impact on public health of the updated solid waste incinerator. Addressing dioxins and dioxin-like compounds, specific aims of this study were: (i) to determine whether living in the vicinity of the Meia Serra incinerator increases the dioxin body burden of the general population; (ii) to investigate other potential determinants of dioxin exposure in this population for prevention priorities; (iii) to provide data on the extent and pattern of exposure of the general population to dioxins and dioxin-like compounds by determining respective toxicity levels and congeners profile in blood samples.

Dose-response relationships and risk estimates for the induction of cancer due to low doses of low-LET radiation

International Nuclear Information System (INIS)

Elaguppillai, V.

1981-01-01

Risk estimates for radiation-induced cancer at low doses can be obtained only by extrapolation from the known effects at high doses and high dose rates, using a suitable dose-response model. The applicability of three different models, linear, sublinear and supralinear, are discussed in this paper. Several experimental studies tend to favour a sublinear dose-response model (linear-quadratic model) for low-LET radiation. However, human epidemiological studies do not exclude any of the dose-response relationships. The risk estimates based on linear and linear quadratic dose-response models are compared and it is concluded that, for low-LET radiation, the linear dose-response model would probably over-estimate the actual risk of cancer by a factor of two or more. (author)

AN ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA) FOR DETERMINING DIOXINS IN SEDIMENT AND SOIL SAMPLES

Science.gov (United States)

The dioxins comprise a family of compounds chemically referred to as polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The most toxic of these compounds is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a known human carcinogen. Dioxins are formed ...

2,3,7,8-Tetrachlorodibenzo-p-dioxin induced autophagy in a bovine kidney cell line

International Nuclear Information System (INIS)

Fiorito, Filomena; Ciarcia, Roberto; Granato, Giovanna Elvira; Marfe, Gabriella; Iovane, Valentina; Florio, Salvatore; De Martino, Luisa; Pagnini, Ugo

2011-01-01

Highlights: ► TCDD induces cell proliferation in MDBK cells. ► TCDD provokes morphological cell death in MDBK cells. ► TCDD induces autophagy in MDBK cells. ► TCDD induces a down-regulation of telomerase activity, bTERT, c-Myc in MDBK cells. ► TCDD induces an up-regulation of p53 and p21 protein levels in MDBK cells. -- Abstract: The administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to a variety of cultured cells may alter their ability to proliferate and die. In a previous study we demonstrated that TCDD induced proliferation in Madin-Darby Bovine Kidney (MDBK) cells where no signs of apoptosis were observed, but herein, analysis of MDBK cell morphology, in a large number of exposed cells, revealed some alterations, as expanded cytoplasm, an increase of intercellular spaces and many pyknotic nuclei. Hence, the aim of the current study was to elucidate the influences of dioxin on cell proliferation and cell death. We found that dioxin increased proliferation, as well as, activated cell death with autophagy, as we detected by increased amount of LC3-II, an autophagosome marker. Furthermore, formation of acidic vesicular organelles was observed by fluorescence microscopy following staining with the lysosomotropic agent acridine orange. These results were accompanied by down-regulation of telomerase activity, bTERT and c-Myc. Key tumor-suppressor protein p53 and expression of cell cycle inhibitor p21Waf1/Cip1 were activated after TCDD exposure. These changes occurred with activation of ATM phosphorylation in the presence of a decrease in Mdm2 protein levels. Taken together, these results support the idea that TCDD in MDBK cells, may exert its action, in part, by enhancing cell proliferation, but also by modulating the incidence of induced cell death with autophagy.

Age and Chronicity of Administration Dramatically Influenced the Impact of Low Dose Paraquat Exposure on Behavior and Hypothalamic-Pituitary-Adrenal Activity

Directory of Open Access Journals (Sweden)

Chris A. Rudyk

2017-07-01

Full Text Available Little is known of the age-dependent and long-term consequences of low exposure levels of the herbicide and dopaminergic toxicant, paraquat. Thus, we assessed the dose-dependent effects of paraquat using a typical short-term (3 week exposure procedure, followed by an assessment of the effects of chronic (16 weeks exposure to a very low dose (1/10th of what previously induced dopaminergic neuronal damage. Short term paraquat treatment dose-dependently induced deficits in locomotion, sucrose preference and Y-maze performance. Chronic low dose paraquat treatment had a very different pattern of effects that were also dependent upon the age of the animal: in direct contrast to the short-term effects, chronic low dose paraquat increased sucrose consumption and reduced forced swim test (FST immobility. Yet these effects were age-dependent, only emerging in mice older than 13 months. Likewise, Y-maze spontaneous alternations and home cage activity were dramatically altered as a function of age and paraquat chronicity. In both the short and long-term exposure studies, increased corticosterone and altered hippocampal glucocorticoid receptor (GR levels were induced by paraquat, but surprisingly these effects were blunted in the older mice. Thus, paraquat clearly acts as a systemic stressor in terms of corticoid signaling and behavioral outcomes, but that paradoxical effects may occur with: (a repeated exposure at; (b very low doses; and (c older age. Collectively, these data raise the possibility that repeated “hits” with low doses of paraquat in combination with aging processes might have promoted compensatory outcomes.

Carry-over of dioxins and PCBs from feed and soil to eggs at low contamination levels-- influence of mycotoxin binders on the carry-over from feed to eggs.

NARCIS (Netherlands)

Hoogenboom, L A P; Kan, C A; Zeilmaker, Marco J; Eijkeren, Jan C H van; Traag, Win A

2006-01-01

Laying hens were fed with compound feed containing six different levels of dioxins, dioxin-like PCBs and indicator PCBs for a period of 56 days. This was followed by a period of 56 days on clean feed. Dioxin levels in feed varied from background levels to three times the current EU tolerance limit

Carry-over of dioxins and PCBs from feed and soil to eggs at low contamination levels - influence of mycotoxin binders on the carry-over from feed to eggs

NARCIS (Netherlands)

Hoogenboom, L.A.P.; Kan, C.A.; Zeilmaker, M.; Eijkeren, van J.; Traag, W.A.

2006-01-01

Laying hens were fed with compound feed containing six different levels of dioxins, dioxin-like PCBs and indicator PCBs for a period of 56 days. This was followed by a period of 56 days on clean feed. Dioxin levels in feed varied from background levels to three times the current EU tolerance limit

Pentachlorophenol from an old henhouse as a dioxin source in eggs and related human exposure.

Science.gov (United States)

Piskorska-Pliszczynska, Jadwiga; Strucinski, Pawel; Mikolajczyk, Szczepan; Maszewski, Sebastian; Rachubik, Jaroslaw; Pajurek, Marek

2016-01-01

High levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were detected in free-range eggs, and these levels reached a concentration of 29.84 ± 7.45 pg of WHO-TEQ/g of fat. This value exceeded the EU maximum permitted level of 2.5 pg of WHO-TEQ/g of fat for PCDD/F congeners by twelve-fold. A chemical analysis (HRGC-HRMS) revealed elevated amounts of OCDD, OCDF, HxCDD, HpCDD and HpCDF. During the investigation, samples of feed, soil, wall scrapings, wooden ceiling of the henhouse and tissues from laying hens were examined for dioxin contents (30 samples altogether). The long and complicated investigation found that the source of dioxins in the poultry farm was pentachlorophenol-treated wood, which was used as structural components in the 40-year-old farm building adapted to a henhouse. The wooden building material contained PCDD/Fs at a concentration of 3922.60 ± 560.93 pg of WHO-TEQ/g and 11.0 ± 2.8 μg/kg of PCP. The potential risk associated with dioxin intake was characterized by comparing the theoretically calculated weekly and monthly intakes with the toxicological reference values (TRVs), namely the Tolerable Weekly Intake (TWI) and Provisional Tolerable Monthly Intake (PTMI) values of 14 pg of WHO-TEQ/kg of bw and 70 pg of WHO-TEQ/kg of bw, respectively. The intake of dioxins estimated for high egg consumers (approximately 5-6 eggs/week) exceeded the TWI and PTMI values, which may pose a risk of delayed adverse health effects. The estimated dose of PCDD/Fs and DL-PCBs for children consuming 5 eggs per week exceeded the TWI by as much as 450% because of their nearly 5-fold-lower body weight. Although the dioxin intake estimated for the average consumption of eggs in the general population did not exceed any of the TRVs applied (58.7% TWI and 51.1% PTMI), such a situation should be considered unacceptable from a public health perspective because eggs are not the only source of these contaminants. Copyright © 2015

Using the dioxin receptor-calux in vitro bioassay to screen marine harbor sediments for compounds with a dioxin-like mode of action

NARCIS (Netherlands)

Stronkhorst, J.; Leonards, P.E.G.; Murk, A.J.

2002-01-01

The presence of dioxin-like compounds in sediments from harbors and reference sites along the Dutch coast was investigated using the dioxin receptor–chemically activated luciferase gene expression (DR-CALUX) bioassay. The DR-CALUX response varied between 0.2 and 136 ng/kg dry weight expressed in

Technologies for destruction dioxins; Tecnologias de destruccion y eliminacion de dioxinas

Energy Technology Data Exchange (ETDEWEB)

Reinman, D. O.

2002-07-01

Processes which will achieve up to 100-fold reduction of exhaust gas emissions of dioxin as proposed for the new German Standards are reviewed. A combination of processes which remove fly ash, NOx, SOx, HCl and other pollutants will also remove dioxins. Reduction of chlorinated compounds fed to the incinerator is not likely to make any significant difference. Good turbulence with elimination of cold spots in the firebox will ensure initial thermal destruction. Dioxins are synthesized on fly ash particles at temperatures between 200 and 400 degree centigree. Rapid temperature reduction across this range by water injection will greatly reduce dioxin levels. Catalytic inhibitors can also be used. Since dioxin is adsorbed on fly ash, efficient scrubbing is essential for high removal efficiency. Sorption on active carbon fixed filter and flight stream process in fabric filter are also being evaluated. (Author)

Cytogenetic effects of low-dose radiation

International Nuclear Information System (INIS)

Metalli, P.

1983-01-01

The effects of ionizing radiation on chromosomes have been known for several decades and dose-effect relationships are also fairly well established in the mid- and high-dose and dose-rate range for chromosomes of mammalian cells. In the range of low doses and dose rates of different types of radiation few data are available for direct analysis of the dose-effect relationships, and extrapolation from high to low doses is still the unavoidable approach in many cases of interest for risk assessment. A review is presented of the data actually available and of the attempts that have been made to obtain possible generalizations. Attention is focused on some specific chromosomal anomalies experimentally induced by radiation (such as reciprocal translocations and aneuploidies in germinal cells) and on their relevance for the human situation. (author)

Dihydroxylation of 4-substituted 1,2-dioxines

DEFF Research Database (Denmark)

Robinson, Tony V; Pedersen, Daniel Sejer; Taylor, Dennis K

2009-01-01

The synthesis of 2-C-branched erythritol derivatives, including the plant sugar (+/-)-2-C-methylerythritol 2, was achieved through a dihydroxylation/reduction sequence on a series of 4-substituted 1,2-dioxines 3. The asymmetric dihydroxylation of 1,2-dioxines was examined, providing access...... to optically enriched dihydroxy 1,2-dioxanes 4. The synthesized 1,2-dioxanes were converted to other erythro sugar analogues and tetrahydrofurans through controlled cleavage of the endoperoxide linkage....

Low-temperature thermal decomposition of dioxin-like compounds in fly ash: combination of chemical analysis with in vitro bioassays (EROD and DR-CALUX).

Science.gov (United States)

Behnisch, Peter A; Hosoe, Kazunori; Shiozaki, Ken; Ozaki, Hironori; Nakamura, Kazuo; Sakai, Shin-Ichi

2002-12-01

To investigate the dechlorination of fly ash during low-temperature treatment under oxygen-deficient conditions (thermocatalyic treatment or Hagenmaier process), six fly ash samples from six different incineration plants were treated in a laboratory experiment or in the actual plant, either under ideal (400 degrees C, 120 min) or intermediate (300 degrees C, 30 min) conditions. The aim of the present study was to confirm the decrease in the I-TEQ (international toxicity equivalency) of polychlorinated dibenzo-p-dioxins/-furans (PCDD/Fs) and coplanar polychlorinated biphenyls (co-PXBs) and, also for the first time, the decrease in the sum of dioxin-like toxicity (bioassay- or bio-TEQ) of all kinds of other dioxin-like Ah receptor agonists (such as PXDD/Fs, PXBs, PXN, X = Br, F) measured by two state-of-the-art cell-based Ah receptor-dependent bioassays: H4IIE-Ethoxy-Resorufin-o-Deethylase (EROD) and H4IIE-luc/DR-Chemical Activated Luciferase expression (DR-CALUX). The treatment efficiency was calculated on the basis of the reduction in the I-TEQ and bio-TED values. For these fly ash samples, the treatment efficiency, as measured by chemical analysis, was higher than 99%, and 85%-99%, in the case of the bio-TED values, indicating that these Ah receptor binding toxic compounds were sufficiently decomposed. Bio-TEQ values for untreated fly ash samples (n = 6) were on average 1.2 times (range 0.7-1.9), for the H4IIE-EROD assay, and 2.8 times (1.1-4.9), for the DR-CALUX assay, higher than I-TEQ values measured by chemical analyses (sum of PCDD/Fs and co-PCBs). In the case of these fly ash samples treated under ideal conditions and therefore low in contaminants, the bio-TEQ values were on average 1.4 times (range 0.9-1.8), for the H4IIE-EROD assay, and 5.1 times (range 1.2-12), for the DR-CALUX assay, higher than the I-TEQ values.

Dioxin and phthalate uptake and assimilation by the green mussel Perna viridis

International Nuclear Information System (INIS)

Wang, Wen-Xiong; Zhang, Qiong

2013-01-01

In this study, the aqueous uptake and dietary assimilation (trophic transfer) of two endocrine disrupting compounds (dioxin and phathalic acid) in the green mussel Perna viridis were quantified. During short-term exposure period, dioxin rapidly sorbed onto phytoplankton and its accumulation was much higher than that of phthalate. The uptake of these two compounds by the mussels increased with increasing temperature and salinity (for dioxin only). The dietary assimilation of the two contaminants was rather modest (10–64% for dioxin and 20–47% for phthalate), and was greatly dependent on the food species and concentration. Interestingly, dietary assimilation increased with increasing diatom food concentration. Gut passage time was partially responsible for the variable dietary assimilation. Given the high dissolved uptake rate and the modest dietary assimilation, aqueous exposure was predicted to be the dominant bioaccumulation source for both dioxin and phthalate in the green mussels under most conditions. -- Capsule: Aqueous uptake was the predominant pathway for dioxin and phthalate accumulation in marine green mussels

Polybrominated dibenzo-p-dioxins, dibenzofurans, and biphenyls: inclusion in the toxicity equivalency factor concept for dioxin-like compounds.

Science.gov (United States)

van den Berg, Martin; Denison, Michael S; Birnbaum, Linda S; Devito, Michael J; Fiedler, Heidelore; Falandysz, Jerzy; Rose, Martin; Schrenk, Dieter; Safe, Stephen; Tohyama, Chiharu; Tritscher, Angelika; Tysklind, Mats; Peterson, Richard E

2013-06-01

In 2011, a joint World Health Organization (WHO) and United Nations Environment Programme (UNEP) expert consultation took place, during which the possible inclusion of brominated analogues of the dioxin-like compounds in the WHO Toxicity Equivalency Factor (TEF) scheme was evaluated. The expert panel concluded that polybrominated dibenzo-p-dioxins (PBDDs), dibenzofurans (PBDFs), and some dioxin-like biphenyls (dl-PBBs) may contribute significantly in daily human background exposure to the total dioxin toxic equivalencies (TEQs). These compounds are also commonly found in the aquatic environment. Available data for fish toxicity were evaluated for possible inclusion in the WHO-UNEP TEF scheme (van den Berg et al., 1998). Because of the limited database, it was decided not to derive specific WHO-UNEP TEFs for fish, but for ecotoxicological risk assessment, the use of specific relative effect potencies (REPs) from fish embryo assays is recommended. Based on the limited mammalian REP database for these brominated compounds, it was concluded that sufficient differentiation from the present TEF values of the chlorinated analogues (van den Berg et al., 2006) was not possible. However, the REPs for PBDDs, PBDFs, and non-ortho dl-PBBs in mammals closely follow those of the chlorinated analogues, at least within one order of magnitude. Therefore, the use of similar interim TEF values for brominated and chlorinated congeners for human risk assessment is recommended, pending more detailed information in the future.

Achievement report for fiscal 1999 on development of technology to promote reduction of discharge of dioxins. Development of technology to reduce discharge of dioxins in steel manufacturing processes; 1999 nendo dioxin rui haishutsu sakugen sokushin gijutsu kaihatsu seika hokokusho. Seiko kotei ni okeru dioxin rui haishutsu sakugen gijutsu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

Research and development has been performed on a scrap melting process to make dioxins emission concentration to 0.2 ng-TEQ/Nm{sup 3} or less in steel making electric furnaces. The testing facility is of semi-sealed structure, consisting of an arc dissolution furnace, an exhaust gas combustion section, an auxiliary combustion chamber, and a quenching chamber. In the arc dissolution chamber, oxygen and coke are blown in at the same time as turning the arc power supply on, and then secondary combustion air was blown in to burn carbon monoxide gas generated from steel melting. The temperature was raised to about 850 degrees C at which dioxins are decomposed in the auxiliary combustion chamber, and then quenched to 200 degrees C or lower in the quenching chamber to prevent recombination of dioxins. As a result of the test, the exhaust gas temperature after the combustion was estimated to have reached about 900 degrees C at which dioxins are decomposed. In addition, because it was possible to control the exhaust gas temperature at the outlet of the auxiliary combustion chamber to about 850 degrees C and the exhaust gas temperature at the outlet of the quenching chamber to 200 degrees C or lower, the dioxins concentration at the outlet of the quenching chamber was reduced successfully to the targeted value or lower. (NEDO)

Reduction of dioxins-furans formed in combustion and Denovo synthesis

International Nuclear Information System (INIS)

Teller, A.J.

1991-01-01

This paper reports that the acceptance that Denovo synthesis of dioxins and furans occurs on the surface of flyash particles in the temperature range of 200 degrees C-400 degrees C, establishes that post combustion formation of dioxins must be addressed. Dioxin-guran emission reduction can be achieved by addition of synthesis inhibitors, adsorbers, catalytic destruction, or utilization of the inherent capability of silica-alumina for chemisorption of the dioxins and furans within appropriate temperature ranges. The chemisorption procedure, as applied to commercial incinerator operation adds no additional equipment or capital and operating costs to the system. The equilibria rather kinetics controls the absorption. Thus, wide variation in inlets are accepted by the system with no externally induced system response required. Experience at the Commerce, California waste to energy system established reductions of total dioxin and furan cogeners to 1.9 ng/Nm 3 from inlet concentrations ranging from 28 to 735 ng/Mm 3 , within the existing acid gas-particulate-heavy metal removal system, using only temperature control to affect the removal by chemisorption

The special cell effects and somatic consequences of exposure to low dose radiation

International Nuclear Information System (INIS)

Regina Fedortseva; Sergei Aleksanin; Eugene Zheleznyakov; Irina Bychkovskaya

2007-01-01

effects, are not connected to cell division. They appear according to the principle 'all or nothing' in low doses of radiation (in mammals less than 1 Gy). In slowly regenerating tissues these effects (we called them 'alternative effects' result in various subcellular disorders (mostly cytoplasmic). An irreversible change of intracellular homeostasis and dystrophic processes occur within a few hours after exposure. This can result in morphological and functional changes in tissues (depopulation), thus providing for the development of non-carcinogenic somatic consequences of low-dose irradiation. Presumably the changes of this kind are responsible for pathogenesis of the remote somatic disorders following a moderate radiation exposure. The alternative effects are based on special hidden non-mutational alterations. Unlike the traditionally studied alterations they involve all cells of the population and can be inherited by all off-springs (at least in F1). This substantially broadens our notion of biological and applied significance of this phenomenon. Conclusion: The most typical manifestation of alternative effects is a persistently increasing predisposition of cells to damage and death. It is likely that other manifestations are also possible, including a non-specific increase of likelihood (due to impairment of reparation capability) of genome damage. This could give a better insight into the problem of biological risks of cancer transformation and occurrence of hereditary disorders after exposure to low-dose irradiation. It is essential that different biological organisms may develop alternative effects not only due to radiation but other kinds of exposure. This represents a substantial ecological importance of alternative effects and requires development of new methods of assessment of external factors.

A Margin-of-Exposure Approach to Assessment of Noncancer Risks of Dioxins Based on Human Exposure and Response Data

OpenAIRE

Aylward, Lesa L.; Goodman, Julie E.; Charnley, Gail; Rhomberg, Lorenz R.

2008-01-01

Background Risk assessment of human environmental exposure to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDFs) and other dioxin-like compounds is complicated by several factors, including limitations in measuring intakes because of the low concentrations of these compounds in foods and the environment and interspecies differences in pharmacokinetics and responses. Objectives We examined the feasibility of relying directly on human studies of exposure and potential responses to...

Peptides Trapping Dioxins: A Docking-Based Inverse Screening Approach

Directory of Open Access Journals (Sweden)

German Perez

2013-01-01

Full Text Available A rapid and cost-effective computational methodology for designing and rationalizing the selection of small peptides as receptors for dioxin-like compounds was proposed. The backbone of the dioxin Ah receptor binding site was used to design a series of penta- and hexapeptide libraries, with 1400 elements in total. Peptide flexibility was considered and 10 conformers were found to be a good option to represent peptide conformational space with fair speed-accuracy ratio. Each peptide conformer was treated as a possible receptor, generating a dedicated box and then running a docking process using as ligands a family of 76 dibenzo-p-dioxins and 113 dibenzofurans mono- and polychlorinated. Significant predictions were confirmed by comparing primary structure of top and bottom ranked peptides binding dioxins confirming that scrambled positions of the same amino acids gave completely different predicted binding. The hexapeptide EWFQPW, with the best binding score, was chosen as selective sorbent material in solid-phase extraction. The retention performances were tested using the 2,3,7,8-tetrachlorodibenzo-p-dioxin and two polychlorinated biphenyls in order to verify the hexapeptide specificity. The solid-phase extraction experimental procedure was optimized, and analytical parameters of hexapeptide sorbent material were compared with the resin without hexapeptide and a commercial reversed phase cartridge.

Surveillance program on dioxin-like compounds in fatty food in Korea

Energy Technology Data Exchange (ETDEWEB)

Suh Junghyuck; Choi Dongmi; Lee Eunju; Hong Mooki [Korea Food and Drug Administration, Seoul (Korea)

2004-09-15

Although dioxin-like compounds (PCDD/Fs and co-planar PCBs) are environmental contaminants mainly produced from municipal waste incineration, the main route of human intake of these are food. This is because these chemicals have strong tendencies to bioaccumulate in lipid-rich compartments of organisms because of their highly lipophilic property. The contamination levels of dioxin-like compounds depends on species. Species with a higher fat content may have higher contamination levels so that detectable levels are found in fatty food such as meat, eggs, dairy products and fishes. Therefore it is very important to measure the levels of dioxin-like compounds in food(especially fatty food) and to do the risk assessment. The aim of this study was to measure the levels of dioxin-like compounds of retail food in Korea and then assess the health risks potentially associated with the dioxin-like compounds intake.

Dioxin-like chemicals in bivalves and sediment collected from around Australia

Energy Technology Data Exchange (ETDEWEB)

Mueller, J.F.; Muller, R.; Goudkamp, K. [EnTox, The University of Queensland, Brisbane (AU)] (and others)

2004-09-15

The aquatic environment is a significant sink for persistent organic pollutants including dioxin-like chemicals. Besides continuous investigations into sources of higher chlorinated PCDD that have initially been found in soils, and later in dugong and sediments little is known about the levels of dioxin-like chemicals in Australia's aquatic environment. In 2002 the National Dioxin Program (NDP) was commissioned by the Department of Environment and Heritage, Australia. One focus of the NDP was to evaluate background levels of dioxin-like chemicals in Australia's environment. One component of the 'Environmental Levels' project aimed to identify dioxinlike chemicals in the aquatic environment including bivalves collected in both marine, estuarine and freshwater systems. Here we report results from the NDP aquatic study with a particular emphasis on the levels of dioxin-like chemicals in bivalves and sediments respectively in areas from where the bivalves were collected.

Biomonitoring of organic airborne pollutants in particular dioxins and furans

International Nuclear Information System (INIS)

Nobel, W.; Maier-Reiter, W.; Sommer, B.; Finkbeiner, M.

1992-01-01

Standardised grass and borecole cultures were used as bioindicators in the course of planning procedures for emitters. The studies show that such standardised cultures are suitable cumulative indicators of the dioxin and furan content of the atmosphere. Accumulation of dioxins and furans at the site are also evident in the naturally growing vegetation. The levels found for dioxins and furans are calculated by estimating health risks by means of a model of pollutant transfer within the human food chain. (orig.) [de

Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on adipogenic differentiation and insulin-induced glucose uptake in 3T3-L1 cells

Energy Technology Data Exchange (ETDEWEB)

Hsu, Hsin-Fen [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Miaoli County 35053, Taiwan (China); Tsou, Tsui-Chun, E-mail: tctsou@nhri.org.tw [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Miaoli County 35053, Taiwan (China); Chao, How-Ran [Department of Environmental Science and Engineering, National Pingtung University of Science and Technology, Neipu 912, Pingtung, Taiwan (China); Kuo, Ya-Ting; Tsai, Feng-Yuan; Yeh, Szu-Ching [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Miaoli County 35053, Taiwan (China)

2010-10-15

Dioxin exposure has been positively associated with human type II diabetes. Because lipophilic dioxins accumulate mainly in adipose tissue, this study aimed to determine if dioxins induce metabolic dysfunction in fat cells. Using 3T3-L1 cells as an in vitro model, we analyzed the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a model dioxin, on adipogenic differentiation, glucose uptake, and lipolysis. TCDD inhibited adipogenic differentiation, as determined by using oil droplet formation and adipogenic marker gene expression, including PPAR{gamma} (peroxisome proliferator-activated receptor {gamma}), C/EBP{alpha} (CCAAT/enhancer-binding protein {alpha}), and Glut4 (glucose transporter type 4). Effects of TCDD on glucose uptake were evaluated using fully differentiated 3T3-L1 adipocytes, revealing that TCDD significantly attenuated insulin-induced glucose uptake dose dependently. Inhibition of aryl hydrocarbon receptor (AhR) by {alpha}-naphthoflavone ({alpha}-NF), an AhR inhibitor, did not prevent the inhibitory effect of TCDD on glucose uptake, suggesting that TCDD attenuates insulin-induced glucose uptake in an AhR-independent manner. Effects of TCDD on lipolysis were determined using glycerol release assay. We found that TCDD had no marked effect on isoproterenol-induced glycerol release in fully differentiated 3T3-L1 adipocytes. These results provide in vitro evidence of TCDD's effects on fat cell metabolism, suggesting dioxin exposure in development of insulin resistance and type II diabetes.

Measurements of dioxin emissions during co-firing in a fluidised bed

Energy Technology Data Exchange (ETDEWEB)

I. Gulyurtlu; A.T. Crujeira; P. Abelha; I. Cabrita [INETI, Lisbon (Portugal). Departamento de Engenharia Energetica e Controle Ambiental

2007-09-15

The emissions of dioxins could be considerable when fuels with high chlorine content are used, particularly in fluidised beds due to constraints to use temperatures in the range 800-900{sup o}C for other considerations. However, mixing of fuels with different characteristics may lead to a reduction in dioxin emissions. Studies are currently being undertaken at the above-mentioned department in mixing fuels of varying chlorine and sulphur contents to monitor the emissions of dioxins both in the gas and solid phases. Furthermore, the influence of certain elements like Cu in the ash in the emissions of dioxins is also studied to verify the catalytic effect. The INETI pilot-scale test facility is used for the combustion work. Two different coals, namely Colombian and Polish, are used as the base fuel. The supplementary fuels for co-firing include MBM and straw pellets. The combustion temperature is maintained at about 800-830{sup o}C range without any limestone addition. The residence time of over 2 s is respected. Results obtained by far suggest that the presence of sulphur in both fuels have a very strong effect on the eventual emissions of dioxins and the synergy regarding to reduce the dioxins below the levels permitted is possible by mixing fuels based on their characteristics. The paper reports the results obtained and evaluates the effect of fuel nature and operating conditions on the emissions of dioxins. 34 refs., 8 figs., 12 tabs.

Low-dose effects of hormones and endocrine disruptors.

Science.gov (United States)

Vandenberg, Laura N

2014-01-01

Endogenous hormones have effects on tissue morphology, cell physiology, and behaviors at low doses. In fact, hormones are known to circulate in the part-per-trillion and part-per-billion concentrations, making them highly effective and potent signaling molecules. Many endocrine-disrupting chemicals (EDCs) mimic hormones, yet there is strong debate over whether these chemicals can also have effects at low doses. In the 1990s, scientists proposed the "low-dose hypothesis," which postulated that EDCs affect humans and animals at environmentally relevant doses. This chapter focuses on data that support and refute the low-dose hypothesis. A case study examining the highly controversial example of bisphenol A and its low-dose effects on the prostate is examined through the lens of endocrinology. Finally, the chapter concludes with a discussion of factors that can influence the ability of a study to detect and interpret low-dose effects appropriately. © 2014 Elsevier Inc. All rights reserved.

Persistence and dioxin-like toxicity of carbazole and chlorocarbazoles in soil.

Science.gov (United States)

Mumbo, John; Henkelmann, Bernhard; Abdelaziz, Ahmed; Pfister, Gerd; Nguyen, Nghia; Schroll, Reiner; Munch, Jean Charles; Schramm, Karl-Werner

2015-01-01

Halogenated carbazoles have recently been detected in soil and water samples, but their environmental effects and fate are unknown. Eighty-four soil samples obtained from a site with no recorded history of pollution were used to assess the persistence and dioxin-like toxicity of carbazole and chlorocarbazoles in soil under controlled conditions for 15 months. Soil samples were divided into two temperature conditions, 15 and 20 °C, both under fluctuating soil moisture conditions comprising 19 and 44 drying-rewetting cycles, respectively. This was characterized by natural water loss by evaporation and rewetting to -15 kPa. Accelerated solvent extraction (ASE) and cleanup were performed after incubation. Identification and quantification were done using high-resolution gas chromatogram/mass spectrometer (HRGC/MS), while dioxin-like toxicity was determined by ethoxyresorufin-O-deethylase (EROD) induction in H4IIA rat hepatoma cells assay and multidimensional quantitative structure-activity relationships (mQSAR) modelling. Carbazole, 3-chlorocarbazole and 3,6-dichlorocarbazole were detected including trichlorocarbazole not previously reported in soils. Carbazole and 3-chlorocarbazole showed significant dissipation at 15 °C but not at 20 °C incubating conditions indicating that low temperature could be suitable for dissipation of carbazole and chlorocarbazoles. 3,6-Dichlorocarbazole was resistant at both conditions. Trichlorocarbazole however exhibited a tendency to increase in concentration with time. 3-Chlorocarbazole, 3,6-dibromocarbazole and selected soil extracts exhibited EROD activity. Dioxin-like toxicity did not decrease significantly with time, whereas the sum chlorocarbazole toxic equivalence concentrations (∑TEQ) did not contribute significantly to the soil assay dioxin-like toxicity equivalent concentrations (TCDD-EQ). Carbazole and chlorocarbazoles are persistent with the latter also toxic in natural conditions.

Low dose irradiation and biological defense mechanisms

International Nuclear Information System (INIS)

Sugahara, Tsutomu; Sagan, L.A.; Aoyama, Takashi

1992-01-01

It has been generally accepted in the context of radiation protection that ionizing radiation has some adverse effect even at low doses. However, epidemiological studies of human populations cannot definitively show its existence or absence. Furthermore, recent studies of populations living in areas of different background radiation levels reported some decrease in adverse health effects at high background levels. Genetic studies of atomic bomb survivors failed to produce statistically significant findings on the mutagenic effects of ionizing radiation. A British study however, suggests that a father's exposure to low dose radiation on the job may increase his children's risk of leukemia. On the other hand, many experimental studies have raised the possibility that low doses of ionizing radiation may not be harmful or may even produce stimulating or adaptive responses. The term 'hormesis' has come to be used to describe these phenomena produced by low doses of ionizing radiation when they were beneficial for the organisms studied. At the end of the International Conference on Low Dose Irradiation one conclusion appeared to be justified: radiation produces an adaptive response, though it is not universally detected yet. The conference failed to obtain any consensus on risk assessment at low doses, but raised many problems to be dealt with by future studies. The editors therefore believe that the Proceedings will be useful for all scientists and people concerned with radiation protection and the biological effects of low-dose irradiation

Contribution of tobacco smoking to dioxin accumulation: opposite effects according to gender

Energy Technology Data Exchange (ETDEWEB)

Fierens, S.; Bernard, A. [Univ. Catholique de Louvain, Brussels (Belgium); Eppe, G.; Focant, J.F.; Pauw, E. De [Univ. of Liege (Belgium)

2004-09-15

Tobacco smoke contains a variety of polycyclic hydrocarbons including dioxins (polychlorinated dibenzodioxins/dibenzofurans). It has been estimated that smoking 20 cigarettes per day should lead to a dioxin intake almost equivalent to that from food (1 to 3 pg TEQ/kg bw/day), the major source of human exposure. However, studies that have measured dioxins in smokers have found no increased levels, some of them even reporting significantly lower values than in non-smokers. We show here that dioxins concentrations are affected by a gender-smoking interaction that could exert a confounding effect.

Serum Dioxin and Memory Among Veterans of Operation Ranch Hand

National Research Council Canada - National Science Library

Patches, Johnson; Cary, Martin; Grubbs, William; Jackson, William; Robinson, Julie; Pavuk, Marian

2007-01-01

The authors used the Wechsler Memory Scale and the Wechsler Memory Scale-Revised to assess memory among Air Force veterans exposed to Agent Orange and its contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin...

CHLOROBENZENES, CHLOROPHENOLS, PHAS AND LOW CHLORINATED DIOXIN/FURAN POST-BOILER TOXICITY INDICATORS IN MUNICIPAL SOLID WASTE INCINERATORS

Science.gov (United States)

Research has sought indicator compounds for fast and less costly predictive monitoring of polychlorinated dibenzo-p-dioxin and furans, PCDD/F, toxic equivalent concentrations or TEQs. Studies have shown chlorobenzenes and chlorophenols had a good correlation with TEQ, suggesting ...

Topics on study of low dose-effect relationship

Energy Technology Data Exchange (ETDEWEB)

Yamada, Takeshi [Toho Univ., School of Medicine, Tokyo (Japan); Ohyama, Harumi

1999-09-01

It is not exceptional but usually observed that a dose-effect relationship in biosystem is not linear. Sometimes, the low dose-effect relationship appears entirely contrary to the expectation from high dose-effect. This is called a 'hormesis' phenomena. A high dose irradiation inflicts certainly an injury on biosystem. No matter how low the dose may be, an irradiation might inflict some injury on biosystem according to Linear Non-Threshold hypothesis(LNT). On the contrary to the expectation, a low dose irradiation stimulates immune system, and promotes cell proliferation. This is called 'radiation hormesis'. The studies of the radiation hormesis are made on from four points of view as follows: (1) radiation adaptive response, (2) revitalization caused by a low dose stimulation, (3) a low dose response unexpected from the LNT hypothesis, (4) negation of the LNT hypothesis. The various empirical proofs of radiation hormesis are introduced in the report. (M . Suetake)

Topics on study of low dose-effect relationship

International Nuclear Information System (INIS)

Yamada, Takeshi; Ohyama, Harumi

1999-01-01

It is not exceptional but usually observed that a dose-effect relationship in biosystem is not linear. Sometimes, the low dose-effect relationship appears entirely contrary to the expectation from high dose-effect. This is called a 'hormesis' phenomena. A high dose irradiation inflicts certainly an injury on biosystem. No matter how low the dose may be, an irradiation might inflict some injury on biosystem according to Linear Non-Threshold hypothesis(LNT). On the contrary to the expectation, a low dose irradiation stimulates immune system, and promotes cell proliferation. This is called 'radiation hormesis'. The studies of the radiation hormesis are made on from four points of view as follows: (1) radiation adaptive response, (2) revitalization caused by a low dose stimulation, (3) a low dose response unexpected from the LNT hypothesis, (4) negation of the LNT hypothesis. The various empirical proofs of radiation hormesis are introduced in the report. (M . Suetake)

A chain model for dioxins: from emission to cow's milk

NARCIS (Netherlands)

Slob W; Klepper O; van Jaarsveld JA

1993-01-01

A chain model for dioxins is discussed relating dioxin levels in cow's milk to emissions. It was used to explain the elevated dioxin concentrations found in cow's milk at various MSW incinerators. It also served as an aid in the selection of locations for milk analyses in still

Estimation of radiation risks at low dose

International Nuclear Information System (INIS)

1990-04-01

The report presents a review of the effects caused by radiation in low doses, or at low dose rates. For the inheritable (or ''genetic''), as well as for the cancer producing effects of radiation, present evidence is consistent with: (a) a non-linear relationship between the frequency of at least some forms of these effects, with comparing frequencies caused by doses many times those received annually from natural sources, with those caused by lower doses; (b) a probably linear relationship, however, between dose and frequency of effects for dose rates in the region of that received from natural sources, or at several times this rate; (c) no evidence to indicate the existence of a threshold dose below which such effects are not produced, and a strong inference from the mode of action of radiation on cells at low dose rates that no such thresholds are likely to apply to the detrimental, cancer-producing or inheritable, effects resulting from unrepaired damage to single cells. 19 refs

Proteomic Profiling of the Dioxin-Degrading Bacterium Sphingomonas wittichii RW1

Directory of Open Access Journals (Sweden)

David R. Colquhoun

2012-01-01

Full Text Available Sphingomonas wittichii RW1 is a bacterium of interest due to its ability to degrade polychlorinated dioxins, which represent priority pollutants in the USA and worldwide. Although its genome has been fully sequenced, many questions exist regarding changes in protein expression of S. wittichii RW1 in response to dioxin metabolism. We used difference gel electrophoresis (DIGE and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS to identify proteomic changes induced by growth on dibenzofuran, a surrogate for dioxin, as compared to acetate. Approximately 10% of the entire putative proteome of RW1 could be observed. Several components of the dioxin and dibenzofuran degradation pathway were shown to be upregulated, thereby highlighting the utility of using proteomic analyses for studying bioremediation agents. This is the first global protein analysis of a microorganism capable of utilizing the carbon backbone of both polychlorinated dioxins and dibenzofurans as the sole source for carbon and energy.

Optimization of pressurized liquid extraction (PLE) of dioxin-furans and dioxin-like PCBs from environmental samples.

Science.gov (United States)

Antunes, Pedro; Viana, Paula; Vinhas, Tereza; Capelo, J L; Rivera, J; Gaspar, Elvira M S M

2008-05-30

Pressurized liquid extraction (PLE) applying three extraction cycles, temperature and pressure, improved the efficiency of solvent extraction when compared with the classical Soxhlet extraction. Polychlorinated-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like PCBs (coplanar polychlorinated biphenyls (Co-PCBs)) in two Certified Reference Materials [DX-1 (sediment) and BCR 529 (soil)] and in two contaminated environmental samples (sediment and soil) were extracted by ASE and Soxhlet methods. Unlike data previously reported by other authors, results demonstrated that ASE using n-hexane as solvent and three extraction cycles, 12.4 MPa (1800 psi) and 150 degrees C achieves similar recovery results than the classical Soxhlet extraction for PCDFs and Co-PCBs, and better recovery results for PCDDs. ASE extraction, performed in less time and with less solvent proved to be, under optimized conditions, an excellent extraction technique for the simultaneous analysis of PCDD/PCDFs and Co-PCBs from environmental samples. Such fast analytical methodology, having the best cost-efficiency ratio, will improve the control and will provide more information about the occurrence of dioxins and the levels of toxicity and thereby will contribute to increase human health.

Mechanisms associated with the high adsorption of dibenzo-p-dioxin from water by smectite clays.

Science.gov (United States)

Liu, Cun; Li, Hui; Teppen, Brian J; Johnston, Cliff T; Boyd, Stephen A

2009-04-15

Clay minerals may be an important unrecognized sorptive phase for dioxins in soils and clay deposits. Smectites, especially Cs-saponite, effectively adsorbed dibenzo-p-dioxin (DD) from water, reaching 0.8% (wt/wt). Adsorption was promoted by exchangeable cations with low hydration energies, and negative charge in the smectite arising from the tetrahedral siloxane sheets. X-ray diffraction measurements revealed that as DD loading increased to > or =8000 mg/kg the clay basal spacing increased abruptly from 12.3 to 15.2 A demonstrating DD intercalation. The 12.3 A spacing provides an interlayer distance that closely matches the molecular thickness of DD. In this configuration DD is essentially dehydrated as it interacts with the opposing hydrophobic siloxane sheets and with coplanar Cs+ via one of the dioxin ring oxygens. Ab initio calculations suggest that geometrical structures form at higher loadings in which intercalated DD molecules adopt a butterfly geometry sandwiched between dehydrated interlayer Cs+ and the siloxane surface, consistent with the 15.2 A spacing, wherein Cs+ interacts with dioxin ring oxygens and benzene ring pi-electrons. Fourier transformation infrared measurements confirm that adsorbed DD is present in orientations that are not parallel with the interlayer planar siloxane surfaces of smectite.

Human exposure to PCDDs, PCDFs, and dioxin like PCBs in Japan, 2001

Energy Technology Data Exchange (ETDEWEB)

Mato, Y.; Nakayama, S. [Japan Environmental Sanitation Center, Kawasaki (Japan); Suzuki, N.; Morita, M. [National Inst. for Environmental Studies, Tsukuba (Japan); Kadokami, K. [Kitakyushu City Inst. of Environmental Sciences, Kitakyushu (Japan); Katatani, N. [Univ. of Yamanashi, Kofu (Japan); Nakano, T. [Hyogo Prefectural Inst. of Public Health and Environmental Sciences, Kobe (Japan); Matsuoka, T.; Takei, T. [Ministry of the Environment, Tokyo (Japan); Uchiyama, I. [Kyoto Univ. (Japan); Miyata, H. [Setsunan Univ., Hirakata (Japan); Toyoda, M. [Jissen Women' s Univ., Tokyo (Japan)

2004-09-15

In our previous study, we have estimated the level of human exposure to dioxins (PCDDs, PCDFs, and Dioxin like PCBs) in Japan based on dioxins monitoring data and results of total diet studies (TDS) in fiscal 2000 (April 2000- March 2001). It has been reported that the national PCDDs/DFs emission in 2001 against the 1997 level has been reduced by approximately 77% In addition, reduction of environmental levels was reported. The enforcement of Japan's Law Concerning Special Measures against Dioxins has significant impact on the reduction of the average dioxins concentrations in the ambient air. Therefore, the transitions of Japanese dioxins exposure levels in recent years are worthy of attention. In order to determine exposure level in fiscal 2001, collection and compilation for surveillance results derived from the regular environmental monitoring under the law as well as other dioxins surveys by national and local governmental bodies were continued, and the data were analyzed. The exposure level in fiscal 2001 was estimated by a ''point'' estimate (i.e., a single value derived from arithmetic means) approach based on the collected data. Because dioxins exposure is not clearly below the level of concern, an emphasis is placed on the importance of quantitatively characterizing the variability in exposure assessments. Therefore, the ''probabilistic'' approach using a Monte Carlo simulation was also conducted. However, elaboration in curve fitting to the distribution of dioxins intake through diet wasn't completely achieved due to the limitation of TDS data size in fiscal 2000 (n=16) in our previous study. In the present study, the curve fitting to diet were updated and elaborated, based on larger size of TDS data (n=54) by combining all the data in fiscal 1998-2001.

Potencies of red seabream AHR1- and AHR2-mediated transactivation by dioxins: implication of both AHRs in dioxin toxicity.

Science.gov (United States)

Bak, Su-Min; Iida, Midori; Hirano, Masashi; Iwata, Hisato; Kim, Eun-Young

2013-03-19

To evaluate species- and isoform-specific responses to dioxins and related compounds (DRCs) via aryl hydrocarbon receptor (AHR) in the red seabream ( Pagrus major ), we constructed a reporter gene assay system. Each expression plasmid of red seabream AHR1 (rsAHR1) and AHR2 (rsAHR2) together with a reporter plasmid containing red seabream CYP1A 5'-flanking region were transfected into COS-7 cells. The cells were treated with graded concentrations of seven DRC congeners including 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, 1,2,3,4,7,8-HxCDD, 2,3,7,8-TCDF, 2,3,4,7,8-PeCDF, 1,2,3,4,7,8-HxCDF, and PCB126. Both rsAHR1 and rsAHR2 exhibited dose-dependent responses for all the tested congeners. The rsAHR isoform-specific TCDD induction equivalency factors (rsAHR1- and rsAHR2-IEFs) were calculated on the basis of 2,3,7,8-TCDD relative potency derived from the dose-response of each congener. The rsAHR1-IEFs of PeCDD, HxCDD, TCDF, PeCDF, and HxCDF were estimated as 0.17, 0.29, 2.5, 1.5, and 0.27, respectively. For PCB126, no rsAHR1-IEF was given because of less than 10% 2,3,7,8-TCDD maximum response. The rsAHR2-IEFs of PeCDD, HxCDD, TCDF, PeCDF, HxCDF, and PCB126 were estimated as 0.38, 0.13, 1.5, 0.93, 0.20, and 0.0085, respectively. The rsAHR1/2-IEF profiles were different from WHO toxic equivalency factors for fish. In silico docking simulations supported that both rsAHRs have potentials to bind to these congeners. These results suggest that dioxin toxicities may be mediated by both rsAHRs in red seabreams.

Dioxins and endometriosis: cohort study of women in West Virginia

Energy Technology Data Exchange (ETDEWEB)

Diliberto, J.; Birnbaum, L. [U.S. Environmental Protection Agency, NHEERL, ETD, Research Triangle Park, NC (United States); Staats, D.A. [West Virginia Dept. of Environmental Protection, Charleston, WV (United States); Staats, D.A.; Becker, J.; Jude, D.; Chouinard, S.C.; Smith, T. [Marshall Univ. Medical Center, Huntington, WV (United States); Sirinek, L. [West Virginia Dept. of Environmental Protection, Wheeling, WV (United States); Clark, G. [Xenobiotic Detection Systems Inc., Durham, NC (United States); Landy, R. [U.S. Environmental Protection Agency, Region 3, ESC, Ft. Meade, MD (United States)

2004-09-15

The women in this endometriosis/dioxin health study reside in the Kanawha/Ohio River Valley area of West Virginia and comprise a potential cluster (cohort) of individuals who have been exposed to dioxins (dioxin and dioxin-like chemicals) at background levels higher than those seen in other areas of the United States. The emissions from an unique constellation of chemical industries appear to have led to high levels of environmental dioxin contaminants. In addition, this area has a high incidence of endometriosis. Previous animal studies, both in nonhuman primates and rodents, have demonstrated a correlation between dioxin exposure and endometriosis. Human epidemiology studies have suggested an association but have not demonstrated a statistically significant correlation, possibly due to limitations in study design such as insufficient numbers, measurement of only TCDD rather than total equivalents to TCDD (TEQs), and/or lack of surgical ascertainment of endometriosis. The present study is addressing these issues. Thus, we have the unusual congruence of identified emission sources and high background levels of dioxins and a potentially related elevation of endometriosis. Endometriosis is a condition suffered by women in which the endometrial tissue, that usually lines the uterus, migrates to other areas. Most commonly it is found in the abdomen, bladder, ovaries or bowel. Patients with endometriosis experience pelvic pain, irregular bleeding, infertility and other problems. Immune suppression has been associated with severe endometriosis. This debilitating condition is a poorly understood disease. In the United States, this condition affects millions of women in their reproductive years and is showing up more frequently in very young women. Endometriosis will seriously impact future fertility and health care utilization. Data suggest that the rate of endometriosis in the Kanawha and Ohio River valleys is higher than is seen in other regions of the United States.

ENZYME-LINKED IMMUNOSORBENT ASSAY FOR SCREENING DIOXIN SOIL CONTAMINATION BY UNCONTROLLED COMBUSTION DURING INFORMAL RECYCLING IN SLUMS

Science.gov (United States)

Trindade, Mirta; Nording, Malin; Nichkova, Mikaela; Spinnel, Erik; Haglund, Peter; Last, Michael S.; Gee, Shirley; Hammock, Bruce; Last, Jerold A.; González-Sapienza, Gualberto; Brena, Beatriz M.

2010-01-01

Uncontrolled combustion due to garbage recycling is a widespread activity among slum dwellers in distressed economy countries and has been indicated as a major source of dioxin contamination. However, because of the high cost and complexity of gas chromatography/high-resolution mass spectrometry (GC-HRMS) analysis, the magnitude of the problem remains largely unknown. The present study describes a first approach toward the use of a dioxin antibody-based enzyme-linked immunosorbent assay (ELISA) as the basis for a sustainable, simple, and low-cost monitoring program to assess the toxicological impact of uncontrolled combustion in slums. A panel of 16 samples was analyzed by GC-HRMS and ELISA on split extracts. Close to 20% of the analyzed samples showed dioxin concentrations up to almost twice the guidance level for residential soil in several countries, pointing out the need for performing a large-scale monitoring program. Despite the potential for variations in dioxin congener distribution due to the mixed nature of the incinerated material, there was a good correlation between the toxic equivalents as determined by GC-HRMS and ELISA. Furthermore, an interlaboratory ELISA validation showed that the capacity to perform the dioxin ELISA was successfully transferred between laboratories. It was concluded that the ELISA method performed very well as a screening tool to prioritize samples for instrumental analysis, which allows cutting down costs significantly. PMID:18522475

Dioxin exposure of human CD34+ hemopoietic cells induces gene expression modulation that recapitulates its in vivo clinical and biological effects

International Nuclear Information System (INIS)

Fracchiolla, Nicola Stefano; Todoerti, Katia; Bertazzi, Pier Alberto; Servida, Federica; Corradini, Paolo; Carniti, Cristiana; Colombi, Antonio; Cecilia Pesatori, Angela; Neri, Antonino; Deliliers, Giorgio Lambertenghi

2011-01-01

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has a large number of biological effects, including skin, cardiovascular, neurologic diseases, diabetes, infertility, cancers and immunotoxicity. We analysed the in vitro TCDD effects on human CD34 + cells and tested the gene expression modulation by means of microarray analyses before and after TCDD exposure. We identified 257 differentially modulated probe sets, identifying 221 well characterized genes. A large part of these resulted associated to cell adhesion and/or angiogenesis and to transcription regulation. Synaptic transmission and visual perception functions, with the particular involvement of the GABAergic pathway were also significantly modulated. Numerous transcripts involved in cell cycle or cell proliferation, immune response, signal transduction, ion channel activity or calcium ion binding, tissue development and differentiation, female or male fertility or in several metabolic pathways were also affected after dioxin exposure. The transcriptional profile induced by TCDD treatment on human CD34 + cells strikingly reproduces the clinical and biological effects observed in individuals exposed to dioxin and in biological experimental systems. Our data support a role of dioxin in the neoplastic transformation of hemopoietic stem cells and in immune modulation processes after in vivo exposure, as indicated by the epidemiologic data in dioxin accidentally exposed populations, providing a molecular basis for it. In addition, TCDD alters genes associated to glucidic and lipidic metabolisms, to GABAergic transmission or involved in male and female fertility, thus providing a possible explanation of the diabetogenic, dyslipidemic, neurologic and fertility effects induced by TCDD in vivo exposure.

SR-TXRF analysis of trace elements in whole blood and heart of rats: effects of irradiation with low and high doses

Science.gov (United States)

Mota, C. L.; Pickler, A.; Braz, D.; Barroso, R. C.; Mantuano, A.; Salata, C.; Ferreira-Machado, S. C.; Lau, C. C.; de Almeida, C. E.

2018-04-01

In the last decades, studies showed that the exposure to low doses of ionizing radiation of the body could sense and activate the cell signaling pathways needed to respond to any induced cellular damage. This procedure reduces cell killing compared with a single dose of high radiation dose. Damage to the vasculature can affect the function of most body organs by restricting blood flow and oxygen to tissues; however, the heart and brain are of main concern. The precise relationship between long-term health effects and low-dose exposures remain poorly understood. Biological markers are powerful tools that can be used to determine dose- response relationships and to estimate risk, especially when dealing with, the effects of low dose exposures in humans. These markers should be specific, sensitive, as well as easy and fast to quantify. Various types of biologic specimens are potential candidates for identifying biomarkers but blood has the advantage of being minimally invasive to obtain. In this study, we propose to apply total reflection X-ray fluorescence to quantify possible chemical elemental concentration (sulfer, iron, zinc, potassium and calcium) changes in blood and heart tissues of Wistar rats after total body irradiation with low (0.1 Gy) and high (2.5 Gy) doses. The fluorescence measurements were carried out at the X-ray Fluorescence beamline in the Brazilian Synchrotron Light Laboratory. The results showed that the irradiated animals with low doses have significant alterations in blood and cardiac tissue when compared with animals that received high doses of radiation. Taken together the analysis of all the elements, we can observe that the radiation induced oxidative stress may be the leading cause for alteration of the elemental level in the studied samples.

Formation and removal of dioxins in a MSWI during different operating periods

Energy Technology Data Exchange (ETDEWEB)

Wang, H.C.; Hwang, J.F. [Center for Environmental, Safety, and Health Technology, Industrial Technology Research Institute, Hsin-Chu (Taiwan). Environmental Health and Air Pollution Division; Chang, M.B.; Chi, K.H. [National Central University, Chungli (Taiwan). Graduate Inst. of Environmental Engineering

2004-09-15

There was little literature to report the dioxin emission concentrations and characteristics during start-up and burndown periods. This research aims to establish the databases of dioxin concentrations in the flue gas and evaluate the dioxin removal efficiencies by air pollution control devices (APCDs) at different operating periods (during start-up, normal operating and burn down periods).

Late effects of low doses and dose rates

International Nuclear Information System (INIS)

Paretzke, H.G.

1980-01-01

This paper outlines the spectrum of problems and approaches used in work on the derivation of quantitative prognoses of late effects in man of low doses and dose rates. The origins of principal problems encountered in radiation risks assessments, definitions and explanations of useful quantities, methods of deriving risk factors from biological and epidemiological data, and concepts of risk evaluation and problems of acceptance are individually discussed

Total-dose hardness assurance for low earth orbit

International Nuclear Information System (INIS)

Maurer, R.H.; Suter, J.J.

1987-01-01

The Low Earth Orbit radiation environment has two significant characteristics that make laboratory simulation exposures difficult: (1) a low dose rate and (2) many cycles of low dose accumulation followed by dose-free annealing. Hardness assurance considerations for this environment are discussed and related to data from the testing of Advanced Low Power Schottky and High-speed CMOS devices

PCB and Dioxin content of Swedish waste fuels; PCB- och dioxininnehaall i svenska avfallsbraenslen

Energy Technology Data Exchange (ETDEWEB)

Blomqvist, Evalena (Swedish National Testing and Research Inst., Boraas (Sweden)) (and others)

2009-06-15

hazardous waste fractions are not included within the MSW mixture which is used in the normal waste incineration plants in Sweden. Moreover 12 of the PCBs were analyzed in all samples and the calculated toxicity, reported as WHO-PCB, is less or close to, the detection limit <0,02 mug PCB WHO-TEQ/kg. According to EU, waste needs to be destroyed if the so-called low POP content limit (LPCL) is above 15 mg TEQ dioxin/kg. A clear dominance of a few of the higher chlorinated dioxin and PCB congeners were reported in all samples i.e. OCDD, OCDF, 1,2,3,4,6,7,8-HeptaCDD, 1,2,3,4,6,7,8-HpCDF, the two penta chlorinated PCBs 105, 118 and the hexa chlorinated congener 156

FY 1999 report on the results of the investigational study of dioxin emission mechanism/control; 1999 nendo dioxin hassei kiko yokusei chosa kenkyu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

For the purpose of promoting the utilization of energy from waste, studies were conducted on the dioxin emission mechanism and non-Br base fire retardant materials which emit no Br base dioxin, and the FY 1999 results were summarized. In the study, using a small-fluidized bed experimental incinerator, survey was made of effects of organic/inorganic chlorine included in solid general waste on the formation/discharge of dioxins. As a result of the experiment, it was found out that organic chlorine compounds discharge more dioxins than inorganic ones, and that the combustion method in which rapid formation of volatile matter in furnace is controlled to realize the homogeneous mixed state is important for control of dioxins. In the study of non-Br base fire retardant materials, a preliminary experiment was conducted on new fire retardant materials added with inorganic carrier, metal complex, etc. to make the confirmation of fire retardation by liquid phase reaction of polymer in combustion conditions and the study of fire retardation by separating liquid phase reaction, pyrolysis reaction, and gaseous phase reaction. Further, simulation of the combustion of polymer materials was carried out. (NEDO)

U.S. EPA's National Dioxin Air Monitoring Network: Analytical Issues

Science.gov (United States)

The U.S. EPA has established a National Dioxin Air Monitoring Network (NDAMN) to determine the temporal and geographical variability of atmospheric chlorinated dibenzo-p-dioxins (CDDs), furans (CDFs), and coplanar polychlorinated biphenyls (PCBs) at rural and non-impacted locatio...

Relative implications of protective responses versus damage induction at low dose and low-dose-rate exposures, using the microdose approach

Energy Technology Data Exchange (ETDEWEB)

Feinendegen, L.E

2003-07-01

In reviewing tissue effects of low-dose radiation (1) absorbed dose to tissue is replaced by the sum of energy deposited with track events in cell-equivalent tissue micromasses, i.e. with microdose hits, in the number of exposed micromasses and (2) induced cell damage and adaptive protection are related to microdose hits in exposed micromasses for a given radiation quality. DNA damage increases with the number of microdose hits. They also can induce adaptive protection, mainly against endogenous DNA damage. This protection involves cellular defenses, DNA repair and damage removal. With increasing numbers of low linear energy transfer (LET) microdose hits in exposed micromasses, adaptive protection first tends to outweigh damage and then (above 200 mGy) fails and largely disappears. These experimental data predict that cancer risk coefficients derived by epidemiology at high-dose irradiation decline at low doses and dose rates when adaptive protection outdoes DNA damage. The dose-risk function should include both linear and non-linear terms at low doses. (author)

Relative implications of protective responses versus damage induction at low dose and low-dose-rate exposures, using the microdose approach

International Nuclear Information System (INIS)

Feinendegen, L.E.

2003-01-01

In reviewing tissue effects of low-dose radiation (1) absorbed dose to tissue is replaced by the sum of energy deposited with track events in cell-equivalent tissue micromasses, i.e. with microdose hits, in the number of exposed micromasses and (2) induced cell damage and adaptive protection are related to microdose hits in exposed micromasses for a given radiation quality. DNA damage increases with the number of microdose hits. They also can induce adaptive protection, mainly against endogenous DNA damage. This protection involves cellular defenses, DNA repair and damage removal. With increasing numbers of low linear energy transfer (LET) microdose hits in exposed micromasses, adaptive protection first tends to outweigh damage and then (above 200 mGy) fails and largely disappears. These experimental data predict that cancer risk coefficients derived by epidemiology at high-dose irradiation decline at low doses and dose rates when adaptive protection outdoes DNA damage. The dose-risk function should include both linear and non-linear terms at low doses. (author)

Follow-up on analysis of dioxins in residues from Swedish waste incineration; Uppfoeljande undersoekning av dioxin i rester fraan svensk avfallsfoerbraenning

Energy Technology Data Exchange (ETDEWEB)

Lindskog, Aasa (Tyrens, Stockholm (Sweden)) (ed.)

2009-10-15

As a consequence of a debate in the late 1990's, a major study of the residues from waste incineration was performed in Sweden. In 1999, samples were collected from 21 of the 22, at the time, existing plants. Focus of the study was to analyse dioxin in flue gas treatment residue. A few analyses were also done on slag/bottom ash. A new follow-up study was decided to be carried out after some years. The present report present the result from the follow-up study from 2006 where 24 out of 29 waste incineration plants participated. Between 1999 and 2006 a number of changes have taken place in the waste incineration industry. A few new plants have been built, a few have been closed, a new and stricter law has come into force and the technical development has continued. These changes have together led to a positive development for waste incineration. As a result, the dioxin content in the flue gas residues has decreased, when the results from the two studies are being compared. The decrease is even larger for slag/bottom ash. In the 1999 study the dioxin content in the flue gas treatment residues varied from 0,2 ng/g to 18 ng/g (I-TEQ) with an average of 2-3 ng/g. The total amount for all plants was 160 g. The variation between the dioxin content in the flue gas treatment residues in the later study is smaller, the lowest value is 0,3 ng/g and the highest 5 ng/g. The average is 1,6 ng/g and the median is 1,2 ng/g, both lower that the values from 1999. The total dioxin amount for 2006 is larger than for 1999, 185 g. Although, it must be considered that the amount of incinerated waste has almost doubled during the same period. The dioxin content in the slag/bottom ash has decreased since the former study was performed. At 1999, samples of slag/bottom ash from only seven plants were analysed. The median was 0,03 ng/g and the total dioxin amount from all plants was approximated to 10 g. In the 2006 study the median amounted to 0,005 ng/g and the total amount to 9 g

Modification of damage following low doses

International Nuclear Information System (INIS)

Braby, L.A.; Nelson, J.M.; Metting, N.F.

1988-01-01

At very low doses the damage-interaction mechanism is responsible for very little lethal or potentially lethal damage, and repair of the latter should essentially disappear. An alternative model suggests that potentially lethal damage is either repaired with a constant half time or misrepaired at a rate which is proportional to the square of the damage concentration. In this case, as the dose decreases, the probability of misrepair decreases faster than the probability of repair, and repair becomes a more pronounced feature of the cell response. Since the consequence of unrepaired damage is an important question in determining the effects of low doses of radiation delivered at low dose rates, we have attempted to determine which of these two types of models is consistent with the response of plateau-phase CHO cells. In the earlier experiments, there was no indication of repair after a 50-rad exposure with a 24-hour split dose or plating delay; in fact, immediate plating resulted in survival slightly above control and delayed plating in survival slightly below the control value

The effects of chronic low dose irradiation on drosophila melanogaster

International Nuclear Information System (INIS)

Zajnullin, V.G.; Moskalev, A.A.; Shaposhnikov, M.V.; Yuraneva, I.N.; Taskaev, A.I.

2001-01-01

It was investigated the influence of the chronic gamma-irradiation in the dose rate of 0.17 cGy/h on the rate of genetic variability and on the life-span in the laboratory strains of Drosophila melanogaster with genotypic distinguishes in mobile genetic elements and defects in the DNA repair processes. It is shown that the radiation-induced alteration of the traits under study depends from genotype of investigated strains. In the different strains we have observed an increase as well as a decrease of the mutation rate and life-span. Also it was established that irradiation leads to the frequencies of the GD-sterility and mutability of the snw and h(w+) in the P-M and H-E dysgenic crosses. The obtained results suggest that mobile genetic elements play an important role in the forming of genetic effects in response to low dose irradiation. (author)

Toxicological Profile of Ultrapure 2,2′,3,4,4′,5,5′-Heptachlorbiphenyl (PCB 180) in Adult Rats

Science.gov (United States)

Viluksela, Matti; Heikkinen, Päivi; van der Ven, Leo T. M.; Rendel, Filip; Roos, Robert; Esteban, Javier; Korkalainen, Merja; Lensu, Sanna; Miettinen, Hanna M.; Savolainen, Kari; Sankari, Satu; Lilienthal, Hellmuth; Adamsson, Annika; Toppari, Jorma; Herlin, Maria; Finnilä, Mikko; Tuukkanen, Juha; Leslie, Heather A.; Hamers, Timo; Hamscher, Gerd; Al-Anati, Lauy; Stenius, Ulla; Dervola, Kine-Susann; Bogen, Inger-Lise; Fonnum, Frode; Andersson, Patrik L.; Schrenk, Dieter; Halldin, Krister; Håkansson, Helen

2014-01-01

PCB 180 is a persistent non-dioxin-like polychlorinated biphenyl (NDL-PCB) abundantly present in food and the environment. Risk characterization of NDL-PCBs is confounded by the presence of highly potent dioxin-like impurities. We used ultrapure PCB 180 to characterize its toxicity profile in a 28-day repeat dose toxicity study in young adult rats extended to cover endocrine and behavioral effects. Using a loading dose/maintenance dose regimen, groups of 5 males and 5 females were given total doses of 0, 3, 10, 30, 100, 300, 1000 or 1700 mg PCB 180/kg body weight by gavage. Dose-responses were analyzed using benchmark dose modeling based on dose and adipose tissue PCB concentrations. Body weight gain was retarded at 1700 mg/kg during loading dosing, but recovered thereafter. The most sensitive endpoint of toxicity that was used for risk characterization was altered open field behavior in females; i.e. increased activity and distance moved in the inner zone of an open field suggesting altered emotional responses to unfamiliar environment and impaired behavioral inhibition. Other dose-dependent changes included decreased serum thyroid hormones with associated histopathological changes, altered tissue retinoid levels, decreased hematocrit and hemoglobin, decreased follicle stimulating hormone and luteinizing hormone levels in males and increased expression of DNA damage markers in liver of females. Dose-dependent hypertrophy of zona fasciculata cells was observed in adrenals suggesting activation of cortex. There were gender differences in sensitivity and toxicity profiles were partly different in males and females. PCB 180 adipose tissue concentrations were clearly above the general human population levels, but close to the levels in highly exposed populations. The results demonstrate a distinct toxicological profile of PCB 180 with lack of dioxin-like properties required for assignment of WHO toxic equivalency factor. However, PCB 180 shares several toxicological

The European Dioxin Emission Inventory. Stage II. Final report

Energy Technology Data Exchange (ETDEWEB)

Quass, U.; Fermann, M.; Broeker, G.

2001-07-01

For Stage II of the European Dioxin Project the following objectives were set: - Amendment of existing emission data collected for most relevant emission sources in order to reduce uncertainties of emission estimates. Collecting first emission data from countries not yet performing dioxin emission measurement programs. Extending the inventory of dioxin emissions to ambient air produced in Stage I by a complementary study on emissions to land and water. Extending the regional scope of data collection to countries in Central Europe. The report of Stage II of the European Dioxin Project is presented in 3 Volumes. Volume 1 contains an overview on the background and approach of different activities carried out and on the results obtained. These results are put into a broader view regarding the dioxin reduction measures in Europe leading to conclusions and recommendation for future work. Volume 2 of the report contains a detailed presentation of the sub-projects carried out. The chapters of Volume 2 are structured in a similar manner and start with a short summary in order to allow for a fast cross-reading. In the case of the desk-top studies an overview of the main results or statements is given. Regarding emission measurements details on the experimental set-up and the facilities being investigated are presented. Volume 3 contains a re-evaluation of the dioxin emission inventory presented for the most relevant sources types in the Stage I report. New data gathered from the projects of Stage II as well as from independent activities in the European countries are considered for a revision of the 1995 emission estimates. Additionally, based on current trends and activities the PCDD/F emissions for the years 2000 and 2005 are estimated. Finally, an attempt is made to evaluate the PCDD/F emission reduction rates which might be possible to achieve by the year 2005 compared to 1985. (orig.)

The aromatic polycyclic chlorinated hydrocarbons (HAPC) or ''dioxin'' 30 june 2000; Les hydrocarbures aromatiques polycycliques chlores (HAPC) ou ''dioxines'' 30 juin 2000

Energy Technology Data Exchange (ETDEWEB)

Coulombier, D.; Plenel, L.

2000-06-01

The authors propose in this paper a pocket-book on the dioxin also called HAPC. It presents the emission sources of the dioxin, the population exposed, the effects on the public health, the risk assessment, the dioxin in the food and the environment and the regulation in the domain. (A.L.B.)

Alterations of proteins in murine splenic cells after low dose radiation

International Nuclear Information System (INIS)

Chen Shali; Meng Qingyong; Liu Shuzheng

1997-01-01

Alterations of proteins in the nuclear and cytoplasmic fractions of splenocytes were investigated in mice 4 hours after whole body irradiation with 75 mGy X-rays by 2D-electrophoresis. It was found that alterations of 6 proteins ranging in size from 12 to 43 kD with their pI distribution from 5.6 to 6.6 were displayed in the nuclear fraction of splenocytes in irradiated mice, of which there were 4 novel proteins and 2 up-regulated proteins and at the same time alterations of 10 proteins ranging in size from 10 to 69 kD with their pI distribution from 5.3 to 8.2 were displayed in the cytoplasmic fraction of splenocytes in irradiated mice, of which there were 6 novel proteins, 1 up-regulated proteins and 3 down-regulated proteins, and 3 proteins ranging in size from 24 to 32 kD with their pI distribution from 5.2 to 6.5 disappeared after radiation. It was shown that a 32000/5.2 (MW/pI) protein molecule in the sham-irradiated cytosol of splenocytes appeared in the nuclei after radiation and a 43000/6.3 protein molecule in the sham-irradiated cytosol decreased and appeared in the nuclei after radiation. The results suggest that exchanges of protein molecules occurred between nuclear and cytoplasmic compartments after radiation

Review of State Soil Cleanup Levels for Dioxin (December 2009)

Science.gov (United States)

This final report summarizes a survey of state soil cleanup levels for dioxin and characterizes the science underlying these values. The objective of this project was to summarize existing state cleanup levels for dioxin in soil, together with their scientific bases where availa...

Dioxin generation in hot dip galvanising installations in Spain during 2002; Evaluacion de la generacion de dioxinas y furanos en el sector de galvanizacion en caliente durante el ano 2002

Energy Technology Data Exchange (ETDEWEB)

Fabrellas Rodriguez, B.; Ruiz Lorenzo, M. L.; Martinez Calvo, M. A.; Sanz Chincon, P.; Larrazabal Moya, D.

2003-07-01

Hot dip galvanising sector has been evaluated in the frame of Spanish Dioxin Inventory to estimate their importance as a source of dioxins through their air emissions and wastes generated. The survey has been designed taken into account different pre-treatment surface preparation processes, mainly in degreasing steps. Air emissions, ashes and filter dusts have been sampled and toxic dioxins have been analysed. The results have been correlated with the characteristics of each installation. Dioxins releases to the air are very low when air control devices are used but they are concentrated in filter dusts that appear highly contaminated. Both air and dusts samples present the same dioxin homologue profile and different from ashes, which implies two different ways of formation where organic content, temperature and residence time should place important rules. The organic content could be originated, in some cases, by the degrease step absence, the low efficiency in grease removing and/or by the presence of organic inhibitors and additives used in picking steps. (Author)

Effect of flock Size on Dioxin Levels in eggs from Chickens kept Outside

NARCIS (Netherlands)

Kijlstra, A.; Traag, W.A.; Hoogenboom, L.A.P.

2007-01-01

To decrease dioxin uptake by the general population the European Union (EU) has set limits to the dioxin content of many foodstuffs including eggs. Eggs from free foraging chickens are known to have a higher dioxin content compared with confined laying hens, and the question is whether these eggs

Low dose CT perfusion in acute ischemic stroke.

Science.gov (United States)

Murphy, Amanda; So, Aaron; Lee, Ting-Yim; Symons, Sean; Jakubovic, Raphael; Zhang, Liying; Aviv, Richard I

2014-12-01

The purpose of this investigation is to determine if CT perfusion (CTP) measurements at low doses (LD = 20 or 50 mAs) are similar to those obtained at regular doses (RD = 100 mAs), with and without the addition of adaptive statistical iterative reconstruction (ASIR). A single-center, prospective study was performed in patients with acute ischemic stroke (n = 37; 54% male; age = 74 ± 15 years). Two CTP scans were performed on each subject: one at 100 mAs (RD) and one at either 50 or 20 mAs (LD). CTP parameters were compared between the RD and LD scans in regions of ischemia, infarction, and normal tissue. Differences were determined using a within-subjects ANOVA (p test post hoc analysis (p 50 mAs, there was no significant difference between cerebral blood flow (CBF), cerebral blood volume (CBV), or time to maximum enhancement (Tmax) values for the RD and LD scans in the ischemic, infarcted, or normal contralateral regions (p LD scans for all parameters in the ischemic and normal tissue regions (p > 0.05). CTP-derived CBF and CBV are not different at 50 mAs compared to 100 mAs, even without the addition of ASIR. Current CTP protocols can be modified to reduce the effective dose by 50 % without altering CTP measurements.

Low-dose vaporized cannabis significantly improves neuropathic pain.

Science.gov (United States)

Wilsey, Barth; Marcotte, Thomas; Deutsch, Reena; Gouaux, Ben; Sakai, Staci; Donaghe, Haylee

2013-02-01

We conducted a double-blind, placebo-controlled, crossover study evaluating the analgesic efficacy of vaporized cannabis in subjects, the majority of whom were experiencing neuropathic pain despite traditional treatment. Thirty-nine patients with central and peripheral neuropathic pain underwent a standardized procedure for inhaling medium-dose (3.53%), low-dose (1.29%), or placebo cannabis with the primary outcome being visual analog scale pain intensity. Psychoactive side effects and neuropsychological performance were also evaluated. Mixed-effects regression models demonstrated an analgesic response to vaporized cannabis. There was no significant difference between the 2 active dose groups' results (P > .7). The number needed to treat (NNT) to achieve 30% pain reduction was 3.2 for placebo versus low-dose, 2.9 for placebo versus medium-dose, and 25 for medium- versus low-dose. As these NNTs are comparable to those of traditional neuropathic pain medications, cannabis has analgesic efficacy with the low dose being as effective a pain reliever as the medium dose. Psychoactive effects were minimal and well tolerated, and neuropsychological effects were of limited duration and readily reversible within 1 to 2 hours. Vaporized cannabis, even at low doses, may present an effective option for patients with treatment-resistant neuropathic pain. The analgesia obtained from a low dose of delta-9-tetrahydrocannabinol (1.29%) in patients, most of whom were experiencing neuropathic pain despite conventional treatments, is a clinically significant outcome. In general, the effect sizes on cognitive testing were consistent with this minimal dose. As a result, one might not anticipate a significant impact on daily functioning. Published by Elsevier Inc.

Low dose radiation exposure and atherosclerosis in ApoE-/- mice

International Nuclear Information System (INIS)

Mitchel, R.E.J.; Hasu, M.; Bugden, M.; Wyatt, H.; Little, M.; Hildebrandt, G.; Priest, N.D.; Whitman, S.C.

2010-01-01

The hypothesis that single low dose exposures (0.025-0.5 Gy) to low LET radiation, given at either high (240 mGy/min) or low (1 mGy/min) dose rate, would promote aortic atherosclerosis was tested in female C57BI/6 mice genetically predisposed to this disease (ApoE-/-). Mice were exposed either at early stage disease (2 months of age) and examined 3 or 6 months later, or at late stage disease (8 months of age) and examined 2 or 4 months later. Compared to unexposed controls, all doses given at low or high dose rate at early stage disease had significant inhibitory effects on lesion growth and, at 25 or 50 mGy, on lesion frequency. No dose given at low dose rate had any effect on total serum cholesterol, but this was elevated by every dose given at high dose rate. Exposures at low dose rate had no effect on the percentage of lesion lipids contained within macrophages, and, at either high or low dose rate, had no significant effect on lesion severity. Exposure at late stage disease, to any dose at high dose rate, had no significant effect on lesion frequency, but at low dose rate some doses produced a small transient increase in this frequency. Exposure to low doses at low, but not high dose rate, significantly, but transiently reduced average lesion size, and at either dose rate transiently reduced lesion severity. Exposure to any dose at low dose rate (but not high dose rate) resulted in large and persistent decreases in serum cholesterol. These data indicate that a single low dose exposure, depending on dose and dose rate, generally protects against various measures of atherosclerosis in genetically susceptible mice. This result contrasts with the known, generally detrimental effects of high doses on this disease in the same mice, suggesting that a linear extrapolation of risk from high doses is not appropriate. (author)

Dioxin and furan emissions from landfill gas-fired combustion units

International Nuclear Information System (INIS)

Caponi, F.R.; Wheless, E.; Frediani, D.

1998-01-01

The 1990 Federal Clean Air Act Amendments require the development of maximum achievable control technology standards (MACT) for sources of hazardous air pollutants, including landfill gas-fired combustion sources. The Industrial Combustion Coordinated Rulemaking (ICCR) Federal Advisory Committee is a group of stakeholders from the public and private sector whose charge is to develop recommendations for a unified set of federal toxic air emissions regulations. Specifically, the group will establish MACT standards for industrial-commercial-institutional combustion sources. The ICCR proceedings have given rise to considerable interest in potential dioxin and furan emissions from landfill gas-fired combustion units. In order to establish the potential of dioxin and furan emissions from this group of combustion sources, a world-wide literature search was conducted. A total of 22 references were evaluated. The references covered a wide range of test programs, testing methodologies and combustion equipment type. The most abundant data were for landfill gas-fired flares (shrouded and afterburners) and I.C. engines. Because of limitations in obtaining actual test reports with complete lab data and QA/QC results, and a lack of knowledge as to the exact types of waste received at the European landfills, the test data from these sources, for the purposes of this paper, are considered qualitative. The conclusion reached from review of the test data is that there is a potential for dioxin and furan emissions from landfill gas-fired combustion units, but at very low levels for well operated systems

Achievement report for fiscal 1999 on development of 'technology to promote reduction of discharge of dioxins and development of technology to suppress discharge of dioxins in aluminum product manufacturing processes'; 1999 nendo dioxine rui haishutsu sakugen sokushin gijutsu kaihatsu seika hokokusho. Aluminium seihin seizo kotei ni okeru dioxin rui no haishutsu yokusei seigyo no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

Research and development has been performed with an objective to reduce discharge of dioxins in aluminum product manufacturing processes. With regard to the quantity of chlorine used in aluminum molten metal refining process, the refining tests using 100% chlorine gas and the mixed gas (nitrogen gas mixed at 80%) revealed that either gas has approximately the same degassing performance, and the use of the mixed gas can reduce the amount of chlorine used. Dioxin concentrations in the gas discharged from the refining process were measured under the refining condition using less amount of chlorine. As a result, it was verified that, in the case of using 20% chlorine gas plus 80% nitrogen gas, the concentrations of dioxins decrease to about l/6, or 0.6 ng-TEQ/N{sup 3}. The studies on suppressing the discharge of dioxins from the facility to wash chlorine treatment exhaust gas discovered that dioxin concentration in the scrubber circulating solution can be suppressed to 1/10 or less by means of gravity precipitation and separation of the suspended liquid. It was also made clear that pH should preferably be controlled to 10.5 to separate suspended substances from the precipitated solution. (NEDO)

Low Dose Vaporized Cannabis Significantly Improves Neuropathic Pain

Science.gov (United States)

Wilsey, Barth; Marcotte, Thomas D.; Deutsch, Reena; Gouaux, Ben; Sakai, Staci; Donaghe, Haylee

2013-01-01

We conducted a double-blind, placebo-controlled, crossover study evaluating the analgesic efficacy of vaporized cannabis in subjects, the majority of whom were experiencing neuropathic pain despite traditional treatment. Thirty-nine patients with central and peripheral neuropathic pain underwent a standardized procedure for inhaling either medium dose (3.53%), low dose (1.29%), or placebo cannabis with the primary outcome being VAS pain intensity. Psychoactive side-effects, and neuropsychological performance were also evaluated. Mixed effects regression models demonstrated an analgesic response to vaporized cannabis. There was no significant difference between the two active dose groups’ results (p>0.7). The number needed to treat (NNT) to achieve 30% pain reduction was 3.2 for placebo vs. low dose, 2.9 for placebo vs. medium dose, and 25 for medium vs. low dose. As these NNT are comparable to those of traditional neuropathic pain medications, cannabis has analgesic efficacy with the low dose being, for all intents and purposes, as effective a pain reliever as the medium dose. Psychoactive effects were minimal and well-tolerated, and neuropsychological effects were of limited duration and readily reversible within 1–2 hours. Vaporized cannabis, even at low doses, may present an effective option for patients with treatment-resistant neuropathic pain. PMID:23237736

Identification of novel low-dose bisphenol a targets in human foreskin fibroblast cells derived from hypospadias patients.

Directory of Open Access Journals (Sweden)

Xian-Yang Qin

Full Text Available The effect of low-dose bisphenol A (BPA exposure on human reproductive health is still controversial. To better understand the molecular basis of the effect of BPA on human reproductive health, a genome-wide screen was performed using human foreskin fibroblast cells (hFFCs derived from child hypospadias (HS patients to identify novel targets of low-dose BPA exposure.Gene expression profiles of hFFCs were measured after exposure to 10 nM BPA, 0.01 nM 17β-estradiol (E2 or 1 nM 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD for 24 h. Differentially expressed genes were identified using an unpaired Student's t test with P value cut off at 0.05 and fold change of more than 1.2. These genes were selected for network generation and pathway analysis using Ingenuity Pathways Analysis, Pathway Express and KegArray. Seventy-one genes (42 downregulated and 29 upregulated were identified as significantly differentially expressed in response to BPA, among which 43 genes were found to be affected exclusively by BPA compared with E2 and TCDD. Of particular interest, real-time PCR analysis revealed that the expression of matrix metallopeptidase 11 (MMP11, a well-known effector of development and normal physiology, was found to be inhibited by BPA (0.47-fold and 0.37-fold at 10 nM and 100 nM, respectively. Furthermore, study of hFFCs derived from HS and cryptorchidism (CO patients (n = 23 and 11, respectively indicated that MMP11 expression was significantly lower in the HS group than in the CO group (0.25-fold, P = 0.0027.This present study suggests that an involvement of BPA in the etiology of HS might be associated with the downregulation of MMP11. Further study to elucidate the function of the novel target genes identified in this study during genital tubercle development might increase our knowledge of the effects of low-dose BPA exposure on human reproductive health.

Low dose epidemiologic studies

International Nuclear Information System (INIS)

Anon.

1990-01-01

In this chapter the BEIR committee has reviewed low-dose irradiation studies since the BEIR III report. They have considered the carcinogenic effectiveness of low-LET in populations exposed to radiation from a number of different sources: diagnostic radiography; fallout from nuclear weapons testing; nuclear installations; radiation in the workplace and high levels of natural background radiation

Systematic analysis and the overall toxicity evaluation of dioxins and hexachlorobenzene in human milk

Energy Technology Data Exchange (ETDEWEB)

Saito, K.; Ogawa, M.; Takekuma, M.; Ohmura, A. [Dioxin Reasearch Group, Saitama Institute of Public Health, Saitama (Japan); Kawaguchi, M.; Ito, R.; Nakazawa, H. [Hoshi Univ., Tokyo (Japan). Dept. of Analytical Chemistry; Matsuki, Y. [Japan Food Hygiene Association, Tokyo (Japan). Inst. of Food Hygiene

2004-09-15

The hexachlorobenzene (HCB), a type of organochlorine pesticide (OCP), was used as a fungicide for seed, and as a wood preservative. Also, HCB exists in the by-products found in the manufacturing process of chlorinated organic chemicals, and is generated by garbage incineration. The HCB is a so-called, unintended toxic pollutant as well as dioxins, and HCB is then specified for Persistent Organic Pollutants (POPs). According to a recent study, it was pointed out that HCB binds to the aryl hydrocarbon (Ah) receptor, resulting in dioxin-like effects and bioaccumulates. Therefore, the overall toxicity evaluation of dioxins and HCB in human body, especially in human milk, should be examined, because HCB is universally detected in human milk. Until now, many studies regarding the dioxins or OCPs polluted in human milk have been reported. However, there are only a few reports that analyze both dioxins and HCB in the same sample, because repeated sampling and large amounts of samples of human milk were generally difficult to acquire. Moreover, few studies are available for the overall toxicity evaluation of dioxins and HCB in human milk. The aim of the present study was to develop the systematic analysis method of dioxins and HCB, and to obtain additional information about the overall toxicity evaluation of dioxins and HCB in human milk. The correlation between the HCB residue level and each dioxin isomer in the human milk was also considered.

Low dose irradiation facilitates hepatocellular carcinoma genesis involving HULC.

Science.gov (United States)

Li, Yuan; Ge, Chang; Feng, Guoxing; Xiao, Huiwen; Dong, Jiali; Zhu, Changchun; Jiang, Mian; Cui, Ming; Fan, Saijun

2018-03-24

Irradiation exposure positive correlates with tumor formation, such as breast cancer and lung cancer. However, whether low dose irradiation induces hepatocarcinogenesis and the underlying mechanism remain poorly defined. In the present study, we reported that low dose irradiation facilitated the proliferation of hepatocyte through up-regulating HULC in vitro and in vivo. Low dose irradiation exposure elevated HULC expression level in hepatocyte. Deletion of heightened HULC erased the cells growth accelerated following low dose irradiation exposure. CDKN1, the neighbor gene of HULC, was down-regulated by overexpression of HULC following low dose irradiation exposure via complementary base pairing, resulting in promoting cell cycle process. Thus, our findings provide new insights into the mechanism of low dose irradiation-induced hepatocarcinogenesis through HULC/CDKN1 signaling, and shed light on the potential risk of low dose irradiation for the development of hepatocellular carcinoma in pre-clinical settings. © 2018 Wiley Periodicals, Inc.

Low-dose effect on blood chromosomes

International Nuclear Information System (INIS)

Pohl-Rueling, J.

1992-01-01

Linear dose response relationships of biological effects at low doses are experimentally and theoretically disputed. Structural chromosome aberration rates at doses ranging from normal background exposures up to about 30 mGy/yr in vivo and up to 50 mGy in vitro were investigated by the author and other scientists. Results are comparable and dose effect curves reveal following shapes; within the normal burden and up to 2-10 mGy/yr in vivo rates they increase sharply to about 3-6 times the lowest values; subsequent doses either from natural, occupational or accidental exposures up to about 30 mGy/yr yield either constant aberration rates, assuming a plateau, or perhaps even a decrease. In vitro experiments show comparable results up to 50 mGy. Other biological effects seem to have similar dose dependencies. The non-linearity of low-dose effects can be explained by induction of repair enzymes at certain damage to the DNA. This hypothesis is sustained experimentally and theoretically by several papers in literature. (author). 14 refs., 5 figs

Risk of radiation-induced cancer at low doses and low dose rates for radiation protection purposes

International Nuclear Information System (INIS)

1995-01-01

The aim of this report is to provide an updated, comprehensive review of the data available for assessing the risk of radiation-induced cancer for radiation protection purposes. Particular emphasis is placed on assessing risks at low doses and low dose rates. The review brings together the results of epidemiological investigations and fundamental studies on the molecular and cellular mechanisms involved in radiation damage. Additionally, this information is supplemented by studies with experimental animals which provide further guidance on the form of the dose-response relationship for cancer induction, as well as on the effect of dose rate on the tumour yield. The emphasis of the report is on cancer induction resulting from exposure to radiations with a low linear energy transfer (LET). The work was performed under contract for the Institut de Protection et de Surete Nucleaire, Fontenay-aux-Roses, Paris, France, whose agreement to publish is gratefully ackowledged. It extends the advice on radiation risks given in Documents of the NRPB, 4 No. 4 (1993). (Author)

Internal dose-effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in gonadotropin-primed weanling rat model

Energy Technology Data Exchange (ETDEWEB)

Shirota, Mariko [Food and Drug Safety Center, Hatano Research Institute, Kanagawa (Japan); Kaneko, Toyozo [National Institute of Health Sciences, Tokyo (Japan); Okuyama, Mitsunobu [Food and Drug Safety Center, Hatano Research Institute, Kanagawa (Japan); TEIZO Medical Co., Ltd., Kawasaki (Japan); Sakurada, Yosuke; Shirota, Kinji [Azabu University, Research Institute of Biosciences, Kanagawa (Japan); Matsuki, Yasuhiko [Food and Drug Safety Center, Hatano Research Institute, Kanagawa (Japan); Japan Food Hygiene Association, Tokyo (Japan)

2007-04-15

Single sc injection of 5 IU equine chorionic gonadotropin (eCG) induces ovulation in weanling female rats 3 days later. It has been shown that treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) 24 h before eCG injection reduces eCG-stimulated ovarian hypertrophy and inhibits ovulation. The present study intended to compare internal dose-effects of TCDD between these endpoints and representative endpoints for TCDD toxicity, such as weights of the liver and thymus, in weanling female rats given orally 0, 1, 4 or 16 {mu}g/kg TCDD 24 h before eCG injection on postnatal day 25. Measurement of plasma TCDD concentrations by ELISA at 6, 72 and 96 h after TCDD revealed that significant levels of TCDD were maintained in systemic circulation until 96 h (on the day of induced ovulation) with the highest level at 6 h after TCDD treatment. Ovarian TCDD concentrations varied similarly and tended to be higher than those in the thymus at all time points, whereas hepatic concentrations of TCDD were the highest among the tissues. Although {>=} 4 {mu}g/kg TCDD affected the weights of the thymus and liver, no differences were observed in ovarian weights at any time point or in ovulation between corn oil-treated and TCDD-treated groups. Furthermore, ovarian levels of representative mRNAs in follicles were not affected by TCDD treatment. Since TCDD increased the amount of cytochrome P450 1A1 mRNA in the ovary, the administered TCDD stimulated the aryl hydrocarbon receptor-signaling pathway. From these results, we concluded that thymus weights of weanling female rats responded to TCDD at a lower internal dose as compared with that ovarian hypertrophy and follicular growth from early antral stage to ovulation would respond to. (orig.)

Optimization of an oil leaching process to reduce the level of dioxins and dioxin-like PCBs in fishmeal.

Science.gov (United States)

Oterhals, Åge; Kvamme, Bjørn

2013-05-01

Fishmeal produced from fish caught in polluted fishing areas might contain dioxins and dioxin-like polychlorinated biphenyls (PCBs) above maximum permitted levels (MPL) for use in feed. Decontamination of the fishmeal can be achieved by hexane extraction. The principal objective of this study was to optimize a more environmentally friendly alternative based on oil leaching of the moist presscake intermediate product during fishmeal manufacturing. A central composite design and response surface methodology was used to study the influence of the process variables temperature (T), presscake moisture content (MC) and leaching time (LT) on the decontamination process. A significant squared MC effect was observed, resulting in an optimum leaching rate at 27% MC. This corresponds to 5% improved dibenzo-p-dioxin/dibenzo furan (PCDD/F)-PCB toxic equivalent (TEQ) reduction compared to normal presscake (55% MC). The initial leaching rate was fast, with a TEQ reduction of 69% after only 2 min at 87 °C and 55% MC. Under the best experimental conditions (87 °C, 38% MC, 12 min LT) a TEQ reduction of 82% was achieved. Excess oil in the presscake after the leaching operation could be removed by use of a water washing step. No reduction in protein quality measured by mink digestibility could be observed. The results confirm that the oil leaching process is robust and offers easily achievable TEQ levels well below present MPLs based on process conditions normally used by the industry. Comparative effects on non-dioxin-like PCBs are expected. © 2012 Society of Chemical Industry.

Emissions and dioxins formation from waste incinerators

International Nuclear Information System (INIS)

Carbone, A.I.; Zagaroli, M.

1989-01-01

This paper describes current knowledge on dioxins formation and emission from waste incinerators. The pertinent Italian law and effects on man health are dealt with, too. The picture of existing municipal incinerators is presented concerning both the actual emission levels and the monitored levels in the environment. Sampling and analysis systems of these organic chlorinated micro-pollutants and current theories on precursors, formation mechanisms, and influence of different parameters are also described. The last section deals with some of the techniques that can be used to reduce dioxins formation and emission from municipal incinerators. (author)

Low doses of gamma radiation in soybean

International Nuclear Information System (INIS)

Franco, José G.; Franco, Suely S.H.; Villavicencio, Anna L.C.; Arthur, Valter; Arthur, Paula B.; Franco, Caio H.

2017-01-01

The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Dry soya seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.210 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. A treatment with four radiation doses was applied as follows: 0 (control); 12.5; 25.0 and 50.0 Gy. Seed germination and harvested of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds number and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were the doses of 12.5 and 50.0 Gy. The results show that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

Low doses of gamma radiation in soybean

Energy Technology Data Exchange (ETDEWEB)

Franco, José G.; Franco, Suely S.H.; Villavicencio, Anna L.C., E-mail: zegilmar60@gmail.com, E-mail: gilmita@uol.com.br, E-mail: villavic@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Arthur, Valter; Arthur, Paula B., E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Franco, Caio H. [Universidade Federal de São Paulo (UNIFESP), SP (Brazil). Departamento de Microbiologia, Imunologia e Parasitologia

2017-07-01

The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Dry soya seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.210 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. A treatment with four radiation doses was applied as follows: 0 (control); 12.5; 25.0 and 50.0 Gy. Seed germination and harvested of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds number and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were the doses of 12.5 and 50.0 Gy. The results show that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

Correlations between dioxin-like and indicators PCBs: Potential consequences for environmental studies involving fish or sediment

International Nuclear Information System (INIS)

Babut, M.; Miege, C.; Villeneuve, B.; Abarnou, A.; Duchemin, J.; Marchand, P.; Narbonne, J.F.

2009-01-01

Among the numerous PCB congeners, most of the dioxin-like PCBs (DL-PCBs) need to be characterized by hyphenated techniques. It has been shown in several instances that these congeners are well related to the total PCB content in fish. We examined datasets collected mainly in France, on freshwater and marine fish and sediments. A statistical model linking DL- and indicator PCBs was developed for a dataset composed of freshwater fishes, and proved to predict well DL-PCBs from indicator PCBs in all other fish sets, including marine ones. Type II error rates remained low in almost all fish sets. A similar correlation was observed in sediments. Non-dioxin-like PCBs elicit various adverse effects and represent 95% of the total PCBs. A European guideline for them is needed; the correlation between DL- and indicator PCBs could help develop this standard in the future. - Dioxin-like PCBs in fish and maybe sediments are rather well predicted by indicator PCBs.

CHLOROBENZENES, CHLOROPHENOLS, PAHS AND LOW CHLORINATED DIOXIN/FURAN AS POST-BOILER TOXICITY INDICATORS IN MUNICIPAL SOLID WASTE INCINERATORS

Science.gov (United States)

Numerous research studies have been conducted to establish indicator compounds for fast and less costly predictive monitoring of polychlorinated dibenzo-p-dioxin and furan (PCDD/F) toxic equivalent concentrations (TEQs). Many studies have shown that chlorobenzenes and chlorophen...

Low-dose responses to 2,3,7,8-tetrachlorodibenzo-p-dioxin in single living human cells measured by synhrotron infrared spectromicroscopy

International Nuclear Information System (INIS)

Holman, Hoi-Ying N.; Goth-Goldstein, R.; Martin, M.C.; Russel, M.L.; McKinney, W.R.

1999-01-01

We report synchrotron radiation-based (SR) Fourier-transform infrared (FTIR) spectromicroscopy measurements of HepG2 cells exposed to an environmental contaminant that is a known ligand for the aryl hydrocarbon receptor (AhR). Measurements were made on cells treated with an AhR-binding model compound 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Compared to untreated control cells, treated cells display unique spectral changes with TCDD concentrations of 0.01 to 10.0 nanomolar (nM). Key spectral changes involve P=O, C-O and C-H stretching bands. The first changes are related to the environment of the phosphate backbone of nucleic acids. The C-H stretching bands data show a relative increase in the number of methyl to methylene groups. We find an excellent correlation between spectral changes and an increase in CYP1A1 expression measured by the reverse transcriptase polymerase chain reaction (RT-PCR) technique demonstrating that the SR-FTIR method is observing cellular biochemical changes related to this gene expression pathway. Finally, we discuss the potential use of SR-FTIR spectromicroscopy as a diagnostic tool for monitoring cellular exposure and early molecular responses to environmental pollutants

Dioxines en PCB's in Chinese wolhandkrab; invloed van grootte en variatie door het seizoen

NARCIS (Netherlands)

Kotterman, M.J.J.; Vries, de P.; Leeuwen, van S.P.J.; Hoogenboom, L.A.P.

2015-01-01

De monitoringsstudies naar de vervuilingsgraad van Chinese Wolhandkrab (WHK) die vanaf 2010 in Nederlandse wateren worden uitgevoerd tonen aan dat de WHK sterk vervuild kan zijn met polychloordibenzo-p-dioxines en -furanen (PCDD/F's, verderop aangeduid als 'dioxines'), met dioxine-achtige

Optimizing bulk milk dioxin monitoring based on costs and effectiveness

NARCIS (Netherlands)

Lascano Alcoser, V.; Velthuis, A.G.J.; Fels-Klerx, van der H.J.; Hoogenboom, L.A.P.; Oude Lansink, A.G.J.M.

2013-01-01

Dioxins are environmental pollutants, potentially present in milk products, which have negative consequences for human health and for the firms and farms involved in the dairy chain. Dioxin monitoring in feed and food has been implemented to detect their presence and estimate their levels in food

Wound trauma alters ionizing radiation dose assessment

Directory of Open Access Journals (Sweden)

Kiang Juliann G

2012-06-01

Full Text Available Abstract Background Wounding following whole-body γ-irradiation (radiation combined injury, RCI increases mortality. Wounding-induced increases in radiation mortality are triggered by sustained activation of inducible nitric oxide synthase pathways, persistent alteration of cytokine homeostasis, and increased susceptibility to bacterial infection. Among these factors, cytokines along with other biomarkers have been adopted for biodosimetric evaluation and assessment of radiation dose and injury. Therefore, wounding could complicate biodosimetric assessments. Results In this report, such confounding effects were addressed. Mice were given 60Co γ-photon radiation followed by skin wounding. Wound trauma exacerbated radiation-induced mortality, body-weight loss, and wound healing. Analyses of DNA damage in bone-marrow cells and peripheral blood mononuclear cells (PBMCs, changes in hematology and cytokine profiles, and fundamental clinical signs were evaluated. Early biomarkers (1 d after RCI vs. irradiation alone included significant decreases in survivin expression in bone marrow cells, enhanced increases in γ-H2AX formation in Lin+ bone marrow cells, enhanced increases in IL-1β, IL-6, IL-8, and G-CSF concentrations in blood, and concomitant decreases in γ-H2AX formation in PBMCs and decreases in numbers of splenocytes, lymphocytes, and neutrophils. Intermediate biomarkers (7 – 10 d after RCI included continuously decreased γ-H2AX formation in PBMC and enhanced increases in IL-1β, IL-6, IL-8, and G-CSF concentrations in blood. The clinical signs evaluated after RCI were increased water consumption, decreased body weight, and decreased wound healing rate and survival rate. Late clinical signs (30 d after RCI included poor survival and wound healing. Conclusion Results suggest that confounding factors such as wounding alters ionizing radiation dose assessment and agents inhibiting these responses may prove therapeutic for radiation combined

An assessment of dioxin levels in processed ball clay from the United States

Energy Technology Data Exchange (ETDEWEB)

Ferrario, J.; Byrne, C. [USEPA, Stennis Space Ctr. Mississippi (United States); Schaum, J. [USEPA, Washington, DC (United States)

2004-09-15

Introduction The presence of dioxin-like compounds in ball clay was discovered in 1996 as a result of an investigation to determine the sources of elevated levels of dioxin found in two chicken fat samples from a national survey of poultry. The investigation indicated that soybean meal added to chicken feed was the source of dioxin contamination. Further investigation showed that the dioxin contamination came from the mixing of a natural clay known as ''ball clay'' with the soybean meal as an anti-caking agent. The FDA subsequently discontinued the use of contaminated ball clay as an anti-caking agent in animal feeds. The source of the dioxins found in ball clay has yet to be established. A comparison of the characteristic dioxin profile found in ball clay to those of known anthropogenic sources from the U.S.EPA Source Inventory has been undertaken, and none of those examined match the features found in the clays. These characteristic features together with the fact that the geologic formations in which the clays are found are ancient suggest a natural origin for the dioxins. The plasticity of ball clays makes them an important commercial resource for a variety of commercial uses. The percentage of commercial uses of ball clay in 2000 included: 29% for floor and wall tile, 24% for sanitary ware, 10% pottery, and 37% for other industrial and commercial uses. The total mining of ball clay in the U.S. for 2003 was 1.12 million metric tons. EPA is examining the potential for the environmental release of dioxins from the processing/use of ball clays and evaluating potential exposure pathways. Part of this overall effort and the subject of this study includes the analysis of dioxin levels found in commercially available ball clays commonly used in ceramic art studios.

Dioxins: validation of food frequency questionnaire and intake in a group of adolescents.

Science.gov (United States)

Zając, Joanna; Skop-Lewandowska, Agata; Helbin, Jadwiga; Potocki, Artur

2017-09-21

A lot of has been heard about dioxins and dioxins-like compounds. These molecules are typically connected in public awareness with affairs. The main source of dioxins for humans is food (90% of typical exposition); thus, assessment of dioxins intake and monitoring of levels of dioxins in food remain an important issue. The aim of the presented work was checking the reproducibility of the authors' semi-quantitative food frequency questionnaire, focusing on products that may contain dioxins and related compounds among adolescents. The uptake of these compounds was also assessed using obtained data. For survey purposes, an album of food products from the questionnaire was constructed. A modified semi-quantitative food frequency questionnaire was constructed and distributed twice in a 2-week time span among 55, 15-year-old, students of secondary schools. The correlation coefficient for both declared frequencies and assessed amounts in the case of the majority of food items was above 0.70. The average assessed intake of dioxins and related compounds was 1.57pgWHO-TEQ/kg body weight per day, and 1.85 pgWHO-TEQ/kg body weight per day, during test and retest, respectively. The modified semi-quantitative food frequency questionnaire is a reproducible tool that can be used for adolescents. Average intake in the analyzed group was lower than the Tolerable Daily Intake, but in contrast to other countries remains one of the highest intakes in a comparable age group. The main sources of dioxins exposition were fish (38%), and meat products.

Dioxin concentration in milk, faeces and tissues of cows related to feed contamination

Energy Technology Data Exchange (ETDEWEB)

Schulz, A.J.; Kamphues, J. [Inst. of Animal Nutrition, School of Veterinary Medicine, Hannover (Germany); Wiesmueller, T. [Federal State Office for Consumer Protection, Potsdam (Germany); Appuhn, H. [Agricultural Investigation and Research Inst., Hameln (Germany); Stehr, D. [District Government of Lueneburg (Germany); Severin, K. [Chamber for Agriculture, Hannover (Germany); Landmann, D. [Agricultural Teaching and Research Facility, Echem (Germany)

2004-09-15

Dioxin contamination of feed and food is a frequently discussed problem, even in the press. The EU legislation sets maximum levels for dioxins in food and feeding stuffs. The dioxin concentration of milk, faeces and tissues of lactating cows grazing in an area of higher dioxin level in the soil and grass, has been tested in part 1 of this small scale field study. Soil intake of grazing cows can reach 1.5 kg soil/d under extreme meteorological conditions. Considering that, the dioxin load of soil and the degree of contamination of feedstuffs could play an important role regarding the exposition of grazing animals. Due to repeated flooding the area the experiment took place was known for a higher dioxin level in soil and grass. The area was separated in a depression and an elevation (in flooding areas depressions are known for their higher dioxin level). Grassland is not only used for grazing animals, but also to obtain hay or grass silage. In part 2 of the field study grass silage obtained on the same area, was fed to dry cows to test whether or not there a risk for milk quality after parturition. The primary aim of this field study was to investigate different matrices at different moments of the experiment. The secondary aim was to develop recommendations on how to prevent or at least how to minimize the dioxin load of feed and with it of food, if food producing animals graze on such areas.

Transplantation Dose Alters the Differentiation Program of Hematopoietic Stem Cells.

Science.gov (United States)

Brewer, Casey; Chu, Elizabeth; Chin, Mike; Lu, Rong

2016-05-24

Hematopoietic stem cell (HSC) transplantation is the most prevalent stem cell therapy, but it remains a risky procedure. To improve this treatment, it is important to understand how transplanted stem cells rebuild the blood and immune systems and how this process is impacted by transplantation variables such as the HSC dose. Here, we find that, in the long term following transplantation, 70%-80% of donor-HSC-derived clones do not produce all measured blood cell types. High HSC doses lead to more clones that exhibit balanced lymphocyte production, whereas low doses produce more T-cell-specialized clones. High HSC doses also produce significantly higher proportions of early-differentiating clones compared to low doses. These complex differentiation behaviors uncover the clonal-level regeneration dynamics of hematopoietic regeneration and suggest that transplantation dose can be exploited to improve stem cell therapy. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Identification of aldehyde oxidase 1 and aldehyde oxidase homologue 1 as dioxin-inducible genes

International Nuclear Information System (INIS)

Rivera, Steven P.; Choi, Hyun Ho; Chapman, Brett; Whitekus, Michael J.; Terao, Mineko; Garattini, Enrico; Hankinson, Oliver

2005-01-01

Aldehyde oxidases are a family of highly related molybdo-flavoenzymes acting upon a variety of compounds of industrial and medical importance. We have identified aldehyde oxidase 1 (AOX1) as a 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin) inducible gene in the mouse hepatoma cell line Hepa-1. AOX1 mRNA levels were not increased by dioxin in mutant derivatives of the Hepa-1 cell line lacking either functional aryl hydrocarbon receptor (AHR) or aryl hydrocarbon receptor nuclear translocator (ARNT) proteins, thus demonstrating that transcriptional induction of AOX1 in response to dioxin occurs through the AHR pathway. Dioxin induction of AOX1 mRNA was also observed in mouse liver. In addition, levels of AOX1 protein as well as those of aldehyde oxidase homologue 1 (AOH1), a recently identified homolog of AOX1, were elevated in mouse liver in response to dioxin. Employing an aldehyde oxidase specific substrate, AOX1/AOH1 activity was shown to be induced by dioxin in mouse liver. This activity was inhibited by a known inhibitor of aldehyde oxidases, and eliminated by including tungstate in the mouse diet, which is known to lead to inactivation of molybdoflavoenzymes, thus confirming that the enzymatic activity was attributable to AOX1/AOH1. Our observations thus identify two additional xenobiotic metabolizing enzymes induced by dioxin

Lateral topography for reducing effective dose in low-dose chest CT.

Science.gov (United States)

Bang, Dong-Ho; Lim, Daekeon; Hwang, Wi-Sub; Park, Seong-Hoon; Jeong, Ok-man; Kang, Kyung Wook; Kang, Hohyung

2013-06-01

The purposes of this study were to assess radiation exposure during low-dose chest CT by using lateral topography and to compare the lateral topographic findings with findings obtained with anteroposterior topography alone and anteroposterior and lateral topography combined. From November 2011 to February 2012, 210 male subjects were enrolled in the study. Age, weight, and height of the men were recorded. All subjects were placed into one of three subgroups based on the type of topographic image obtained: anteroposterior topography, lateral topography, and both anteroposterior and lateral topography. Imaging was performed with a 128-MDCT scanner. CT, except for topography, was the same for all subjects. A radiologist analyzed each image, recorded scan length, checked for any insufficiencies in the FOV, and calculated the effective radiation dose. One-way analysis of variance and multiple comparisons were used to compare the effective radiation exposure and scan length between groups. The mean scan length in the anteroposterior topography group was significantly greater than that of the lateral topography group and the combined anteroposterior and lateral topography group (p topography group (0.735 ± 0.033 mSv) was significantly lower than that for the anteroposterior topography group (0.763 ± 0.038 mSv) and the combined anteroposterior and lateral topography group (0.773 ± 0.038) (p < 0.001). Lateral topographic low-dose CT was associated with a lower effective radiation dose and scan length than either anteroposterior topographic low-dose chest CT or low-dose chest CT with both anteroposterior and lateral topograms.

Formation of dioxins from incineration of foods found in domestic garbage.

Science.gov (United States)

Katami, Takeo; Yasuhara, Akio; Shibamoto, Takayuki

2004-02-15

There has been great concern about the large amounts of garbage produced by domestic households in the modern world. One of the major sources of dioxins (PCDDs, PCDFs, and coplanar PCBs) in the environment is the combustion of domestic waste materials. Exhaust gases from an incinerator, in which mixtures of 67 food items--including fruits, vegetables, pasta, seafoods, meats, and processed foods and seasoned foods--were analyzed for dioxins. Gases collected at the chimney port (9.15 ng/g) contained less total dioxins than those collected at the chamber port (29.1 ng/g). The levels of Cl1-Cl6-PCDDs and Cl1-Cl5-PCDFs were much lower in the gas collected at the chimney port than in the gas collected at the chamber port. The levels of Cl7-Cl8-PCDDs and Cl6-Cl8-PCDFs were higher in the gas collected at the chimney port than in the gas collected at the chamber port. A total of Cl4-Cl8-PCDDs (1.84-3.04 ng/g) comprised over 80% of the total PCDDs formed (2.24-4.00 ng/g). Total PCDFs (16.2-22.6 ng/g) comprised 78-86% of the total dioxins formed (18.9-29.1 ng/g). The PCDFs formed in the greatest amounts were M1CDFs (9.68-10.7 ng/g). Mixtures of commonly consumed food items produced ppb levels of total dioxins in exhaust gases upon combustion, suggesting that incineration of domestic food wastes is one of the sources of dioxins in the environment. A mixture containing some seasoned foods, such as mayonnaise spread on bread, produced more dioxins (29.1 ng/g) than a mixture without seasoned foods did (18.9 ng/g).

First results from dioxins and dioxin-like compounds in the population from Madeira Island, Portugal. Part 2. Biomonitoring in breast milk of women living near to a solid waste incinerator

Energy Technology Data Exchange (ETDEWEB)

M. Fatima Reis; Sampaio, C.; J. Pereira Miguel [Inst. of Preventive Medicine, Lisbon (Portugal); J. Mauricio Melim [Public Health Regional Dept., Funchal (Portugal)

2004-09-15

Although breast-feeding women cannot be representative of the general population, for biomonitoring programs carried out to ultimately assist in policy design to improve public health and safety, it is important to monitor dioxin exposure of this demographic segment through breast milk due to several reasons: 1) breast milk reflects the maternal body burden of lipophilic chemicals and thus it is a measure of prenatal exposure to those compounds; 2) being a human food and the first and main foodstuff for most newborn babies during first lifetime-period, breast milk can be a very significant pathway for infant exposure to dioxins; 3) because large volumes can be collected non-invasively, breast milk is also a convenient sampling specimen for biomonitoring purposes if it is collected taking into consideration all the relevant factors influencing fat content and thus levels of lipophilic compounds, namely the time of sampling during lactation, breastfeeding patterns and maternal characteristics. As part of an Environmental Health Survey Program, relative to an updated incinerator at Meia Serra, Madeira Island, Portugal, dioxin breast milk levels have been determined to provide indicative data on the extent and pattern of exposure of the general population to dioxins and dioxin-like compounds and to investigate potential determinants of dioxin exposure in age reproductive women for prevention priorities. The ultimate objective was to determine whether living in the vicinity of the incinerator increases the maternal dioxin exposure and accordingly their breast-fed infants. Data will also be collected longitudinally in order to provide information on temporal trends in breast milk dioxin levels, which will indicate whether controls on sources of these pollutants are effective.

Are dioxin-like contaminants responsible for the eel ( Anguilla anguilla) drama?

Science.gov (United States)

Palstra, A. P.; van Ginneken, V. J. T.; Murk, A. J.; van den Thillart, G. E. E. J. M.

2006-03-01

Eel populations worldwide are dangerously close to collapsing. Our study is the first to show that current levels of dioxin-like contaminants are strong candidates because of their devastating effects on development and survival of eel embryos. Female and male silver eels were artificially stimulated to maturation and reproduction by treatment with carp pituitary extracts and hCG, respectively. During maturation of female European silver eels, about 60 g fat per kg eel is incorporated in the oocytes. Together with the fat, however, persistent organic pollutants such as dioxin-like polychlorinated biphenyls (PCBs) are incorporated too. The total dioxin-like toxic potency of the individual gonad batches was determined as 2,3,7,8-tetrachlorodibenzo- p-dioxine equivalents (TEQs), using an in vitro reporter gene assay. The observed differences in development and survival showed a significant negative correlation with the TEQ levels in the gonads, already at levels far below the maximal allowable level for fish consumption, i.e., 4 ng TEQ/kg fish. The clear inverse relationship between the TEQ level and the survival period of the fertilised eggs strongly suggests that the current levels of dioxin-like compounds seriously impair the reproduction of the European eel. The peak of the environmental levels of dioxin-like PCBs and the decline of eel coincide worldwide, further suggesting that, in addition to other threats, these contaminants contributed significantly to the current collapse in eel populations.

Brominated Dioxins: Little-Known New Health Hazards - A Review

Directory of Open Access Journals (Sweden)

Piskorska-Pliszczyńska Jadwiga

2014-10-01

Full Text Available This article reviews the present state of the science concerning the polybrominated dibenzo-p-dioxins (PBDDs and dibenzofurans (PBDFs. Everywhere in the world people are exposed to anthropogenic origin chemicals. Some of them are long-lived organic compounds, which persist over the years in the environment. Persistent organic pollutants, such as organohalogen compounds, accumulate in environmental and biological compartments and have adverse effects on the health of humans and animals. Little is known about the brominated and mixed chloro/bromo dioxin and furans. Existing literature suggests that brominated dioxins and furans have similar toxicity profiles to their chlorinated analogues. The exposure data are extremely limited, showing a major data gap in estimating the potential environmental and health risk of these chemicals. The rapid increase in the use of brominated flame retardants (the main source of these pollutants has raised the level of concern over environmental and health damage from brominated dioxins and furans. It is likely that human as well as wildlife exposure to these contaminants will increase with their greater use. The findings reported here present strong evidence of the PBDDs and PBDFs as an emerging new class of contaminants.

Effects of low dose radiation and epigenetic regulation

International Nuclear Information System (INIS)

Jiao Benzheng; Ma Shumei; Yi Heqing; Kong Dejuan; Zhao Guangtong; Gao Lin; Liu Xiaodong

2010-01-01

Purpose: To conclude the relationship between epigenetics regulation and radiation responses, especially in low-dose area. Methods: The literature was examined for papers related to the topics of DNA methylation, histone modifications, chromatin remodeling and non-coding RNA modulation in low-dose radiation responses. Results: DNA methylation and radiation can regulate reciprocally, especially in low-dose radiation responses. The relationship between histone methylation and radiation mainly exists in the high-dose radiation area; histone deacetylase (HDAC) inhibitors show a promising application to enhance radiation sensitivity, no matter whether in low-dose or high-dose areas; the connection between γ-H2AX and LDR has been remained unknown, although γ-H2AX has been shown no radiation sensitivities with 1-15 Gy irradiation; histone ubiquitination play an important role in DNA damage repair mechanism. Moreover, chromatin remodeling has an integral role in DSB repair and the chromatin response, in general, may be precede DNA end resection. Finally, the effect of radiation on miRNA expression seems to vary according to cell type, radiation dose, and post-irradiation time point. Conclusion: Although the advance of epigenetic regulation on radiation responses, which we are managing to elucidate in this review, has been concluded, there are many questions and blind blots deserved to investigated, especially in low-dose radiation area. However, as progress on epigenetics, we believe that many new elements will be identified in the low-dose radiation responses which may put new sights into the mechanisms of radiation responses and radiotherapy. (authors)

Separation and recovery of dioxins using a heavy ion irradiation film

Energy Technology Data Exchange (ETDEWEB)

Takahashi, S; Iida, S; Ohbayashi, Y [Meiji Univ., Kawasaki, Kanagawa (Japan). Faculty of Engineering

2004-02-01

It is demonstrated that halogenated dioxin and its derivatives can be separated from polluted aqueous solutions using pervaporation technique with a nanopore membrane fabricated by heavy-ion beam irradiation. The concentration of dioxin in the sample solution was set below 1 ppm. Polyethyleneterphthalate membrane was used. The membrane was first irradiated with high energy Xe-ions of 450 MeV with a fluence of 3 x 10{sup 3} to 3 x 10{sup 9} ions/cm{sup 2} using TIARA facility of JAERI Takasaki, etched with 6 mol/l NaOH solution resulting in formation of pores with diameter ranging from several to 40 nm, followed by grafting with monomers having affinity to dioxin. Dibenzo-p-dioxin was used to obtain permeability data. Separation factor obtained were within the range from 10 to 50. (S. Ohno)

Dioxins and PCBs in ostrich meat and eggs: levels and implications.

Science.gov (United States)

Piskorska-Pliszczynska, Jadwiga; Strucinski, Pawel; Mikolajczyk, Szczepan; Pajurek, Marek; Maszewski, Sebastian; Pietron, Wojciech

2017-12-01

Although consumption of eggs is an essential part of our diet, limited information is available for table eggs other than those laid by hens. The aim of our study was to determine concentrations of polychlorinated dibenzofurans (PCDD/Fs), dioxin-like (DL-) and non-dioxin-like (NDL) polychlorinated biphenyls (PCBs) in ostrich eggs and meat available on the Polish market, in order to obtain baseline information on the current status of these pollutants in comparison to poultry products. Obtained data were compared with the binding EU limits set for chicken eggs and meat. The levels of individual PCDD/Fs and PCBs congeners varied considerably. The percentage share of total WHO toxic equivalency factor (WHO-TEQ) content indicates the dominant role of PCDD/Fs. High concentrations of PCDD/F and DL-PCBs, in the range of 0.85-74.48 pg WHO-TEQ g -1 fat, were found in ostrich eggs; this exceeds the maximum level permitted for chicken eggs by a factor of up to 15. Eight of the 11 egg samples exceeded the action level for hen eggs. Although the ostrich meat concentrations of PCDD/Fs do not exceed the limit established for poultry muscle (1.75 pg g -1 fat), average contents of PCDD/Fs exceeded almost four times the levels in chicken and turkey muscle. Human exposure was evaluated and the resulting risk was characterised. Taking into account the low average consumption of ostrich eggs, the resulting exposure to dioxins for the general population can be considered as negligibly low. However, the individuals who frequently consume such eggs may be at risk of elevated exposure. Although ostrich products are not consumed frequently, such data are nevertheless useful for food safety purposes.

Dioxin air emission inventory 1990-2004

Energy Technology Data Exchange (ETDEWEB)

Capral Henriksen, T; Illerup, J B; Nielsen, Ole-Kenneth [DMU, Dept. of Policy Analysis (Denmark)

2006-12-15

The present Danish dioxin air emission inventory shows that the emission has been reduced from 68.6 g I-TEQ in 1990 to 22.0 g I-TEQ in 2004, or about 68% over this period. Most of the significant reductions have been achieved in the industrial sector, where emissions have been reduced from 14.67 g I-TEQ in 1990 to 0.17 g I-TEQ in 2004; a reduction of almost 99%. Lower emissions from steel and aluminium reclamation industries form the major part of the reduction within industry. Emissions from waste incineration reduced from 32.5 g I-TEQ in 1990 to 2.1 g ITEQ in 2004; which is approx. 94%. This is due to installation of dioxin abatement equipment in incineration plants. The most important source of emission in 2004 is residential wood combustion, at 8.5 g I-TEQ, or around 40% of the total emission. In 2004, accidental fires, which are estimated to emit 6.1 g I-TEQ/year, are the second most important source, contributing with around 28% of the total emission. The present dioxin emission inventory for Denmark shows how emissions in 2004 come from sources other than waste incineration plants and industry, which were the largest sources in 1990. (au)

Journal Article: Quality Assurance Considerations for An Ambient Dioxin Monitoring Network

Science.gov (United States)

The U.S. Environmental Protection Agency initiated the National Dioxin Air Monitoring Network (NDAMN) in 1998. NDAMN has three primary purposes: 1. To provide measurements of background atmospheric levels of dioxin-like compounds in different geographic regions of the Unite...

A rapid and reagent-free bioassay for the detection of dioxin-like compounds and other aryl hydrocarbon receptor (AhR) agonists using autobioluminescent yeast.

Science.gov (United States)

Xu, Tingting; Young, Anna; Marr, Enolia; Sayler, Gary; Ripp, Steven; Close, Dan

2018-02-01

An autonomously bioluminescent Saccharomyces cerevisiae BLYAhS bioreporter was developed in this study for the simple and rapid detection of dioxin-like compounds (DLCs) and aryl hydrocarbon receptor (AhR) agonists. This recombinant yeast reporter was based on a synthetic bacterial luciferase reporter gene cassette (lux) that can produce the luciferase as well as the enzymes capable of self-synthesizing the requisite substrates for bioluminescent production from endogenous cellular metabolites. As a result, bioluminescent signal production is generated continuously and autonomously without cell lysis or exogenous reagent addition. By linking the expression of the autobioluminescent lux reporter cassette to AhR activation via the use of a dioxin-responsive promoter, the S. cerevisiae BLYAhS bioreporter emitted a bioluminescent signal in response to DLC exposure in a dose-responsive manner. The model dioxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), could be detected within 4 h with a half maximal effective concentration (EC 50 ) of ~ 8.1 nM and a lower detection limit of 500 pM. The autobioluminescent response of BLYAhS to other AhR agonists, including 2,3,7,8-tetrachlorodibenzofuran (TCDF), polychlorinated bisphenyl congener 126 (PCB-126) and 169 (PCB-169), 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin (HxCDD), 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (HpCDD), benzo[a]pyrene (BaP), and β-naphthoflavone (bNF), were also characterized in this study. The non-destructive and reagent-free nature of the BLYAhS reporter assay facilitated near-continuous, automated signal acquisition without additional hands-on effort and cost, providing a simple and cost-effective method for rapid DLC detection.

Systemic effects of low-dose dopamine during administration of cytarabine.

Science.gov (United States)

Connelly, James; Benani, Dina J; Newman, Matthew; Burton, Bradley; Crow, Jessica; Levis, Mark

2017-09-01

Purpose Low-dose dopamine has been utilized to improve renal blood flow, urine output, and reduce drug-induced nephrotoxicity. The purpose of this study was to assess changes in renal function, cardiovascular adverse events, and neurologic toxicity in patients receiving cytarabine with or without low-dose dopamine. Methods A retrospective, single-center, cohort study of patients receiving cytarabine at 667 mg/m 2 /dose or greater, with or without dopamine at ≤5 mcg/kg/min. Cohorts were based upon initiation or absence of low-dose dopamine; cytarabine only, cytarabine + pre- and day of low-dose dopamine, and cytarabine + post-low-dose dopamine. Renal outcomes (urine output, serum creatinine, and creatinine clearance) were compared with baseline and between cohorts. Safety endpoints (arrhythmias, tachycardia, and neurotoxicity) were compared between cohorts based on low-dose dopamine exposure. Results There was no difference in urine output from baseline in all cohorts. Comparing cytarabine only and pre- and day of low-dose dopamine cohorts, there was no difference in urine output. In those receiving low-dose dopamine, there was no difference in serum creatinine and creatinine clearance from baseline. No arrhythmias were documented during the study period, and there was no difference in the incidence of tachycardia between groups (P = 0.66). Neurotoxicity was reported in three patients who were on low-dose dopamine. Conclusion Though variation existed in individual patients administered low-dose dopamine, the use of low-dose dopamine did not significantly impact renal function in this small sample at a single institution. In addition, low-dose dopamine did not negatively impact cardiovascular function.

Alterations in offspring behavior induced by chronic prenatal cocaine dosing.

Science.gov (United States)

Smith, R F; Mattran, K M; Kurkjian, M F; Kurtz, S L

1989-01-01

Sperm-positive female Long-Evans hooded rats were dosed subcutaneously with 10 mg/kg/day cocaine or an equal volume of vehicle (0.9% sterile saline) from gestation day 4 (GD4) through GD18. Offspring were assessed for development of negative geotaxis, righting reflex, spontaneous alternation, and open field activity, and for adult behaviors including DRL-20 acquisition, water maze, visual discrimination, barbiturate sleep time, shuttlebox avoidance, footshock sensitivity, and tail flick latency. Cocaine dosing produced no significant effects on dam weight gain, any measure of litter size and weight, or early postnatal behavioral tests, but there were significant drug effects on development of spontaneous alternation, development of open field activity, DRL-20 acquisition, water maze performance, tail flick, and footshock sensitivity. These data suggest that chronic administration of a modest dose of cocaine during gestation in the rat alters a number of behaviors in the offspring.

Risk assessment of dioxins and dioxin-like PCBs in food. Comments by the German Federal Environmental Agency

Energy Technology Data Exchange (ETDEWEB)

Gies, A.; Neumeier, G.; Rappolder, M.; Konietzka, R. [Federal Environmental Agency, Berlin (Germany)

2004-09-15

Potential health effects of dioxins are an important issue of concern to both politicians and the public. As all humans are exposed to measurable levels of dioxins and related substances, the determination of the tolerated daily intake is a very significant decision. Moreover the revision of this value is not only of academic interest but may also directly influence limit values guiding risk reduction measures, target levels such as those for tolerated residues in food. Council Regulation (EC) No 2375/2001 (setting maximum levels for certain contaminants in food) states in 11: ''Target levels indicate the levels to be achieved in order to ultimately bring human exposure for the majority of the population down to the TWI set by the Scientific Committee''. These target values will be set before 31 December 2004. Thus the level of the TDI may indirectly influence entire sectors of industry in some member countries such as the fish industry of some Nordic States or the feed industry throughout the European Union. Recommendations of a daily intake should involve a very low likelihood of a risk for humans. In particular some prerequisites have to be fulfilled: The proposed TDI has to protect all subpopulations. In the case of dioxin this is of high importance as the exposure of infants through breast feeding may exceed the exposure of adults by one or two orders of magnitude. The degree of uncertainty should be indicated at every step of the risk assessment as requested by the Communication from the Commission on the Precautionary Principle ''Where possible, a report should be made which indicates the assessment of the existing knowledge and the available information, providing the views of the scientists on the reliability of the assessment as well as on the remaining uncertainties. If necessary, it should also contain the identification of topics for further scientific research'' Uncertainty of the models applied should be

Reduced oxygen enhancement ratio at low doses

International Nuclear Information System (INIS)

Palcic, B.; Skarsgard, L.D.

1984-01-01

The oxygen depletion rate in cell suspensions was measured using a Clark electrode. It was found that under experimental conditions used in this laboratory for hypoxic irradiations, the oxygen levels before the start of irradiation are always below 0.1μm, the levels which could give any significant enhancement to radiation inactivation by x-rays. The measured O/sub 2/ depletion rates were comparable to those reported in the literature. Chinese hamster cells (CHO) were made hypoxic by gas exchange, combined with metabolic consumption of oxygen by cells at 37 0 C. Full survival curves were determined in the dose range 0 to 3Gy using the low dose survival assay. The results confirmed the authors' earlier finding that the OER decreases at low doses. The authors therefore believe that the dose-dependent OER is a true radiobiological phenomenon and not an artifact of the experimental method used in the low dose survival assay

Dose Response Model of Biological Reaction to Low Dose Rate Gamma Radiation

International Nuclear Information System (INIS)

Magae, J.; Furikawa, C.; Hoshi, Y.; Kawakami, Y.; Ogata, H.

2004-01-01

It is necessary to use reproducible and stable indicators to evaluate biological responses to long term irradiation at low dose-rate. They should be simple and quantitative enough to produce the results statistically accurate, because we have to analyze the subtle changes of biological responses around background level at low dose. For these purposes we chose micronucleus formation of U2OS, a human osteosarcoma cell line, as indicators of biological responses. Cells were exposed to gamma ray in irradiation rom bearing 50,000 Ci 60Co. After irradiation, they were cultured for 24 h in the presence of cytochalasin B to block cytokinesis, and cytoplasm and nucleus were stained with DAPI and prospidium iodide, respectively. the number of binuclear cells bearing micronuclei was counted under a fluorescence microscope. Dose rate in the irradiation room was measured with PLD. Dose response of PLD is linear between 1 mGy to 10 Gy, and standard deviation of triplicate count was several percent of mean value. We fitted statistically dose response curves to the data, and they were plotted on the coordinate of linearly scale response and dose. The results followed to the straight line passing through the origin of the coordinate axes between 0.1-5 Gy, and dose and does rate effectiveness factor (DDREF) was less than 2 when cells were irradiated for 1-10 min. Difference of the percent binuclear cells bearing micronucleus between irradiated cells and control cells was not statistically significant at the dose above 0.1 Gy when 5,000 binuclear cells were analyzed. In contrast, dose response curves never followed LNT, when cells were irradiated for 7 to 124 days. Difference of the percent binuclear cells bearing micronucleus between irradiated cells and control cells was not statistically significant at the dose below 6 Gy, when cells were continuously irradiated for 124 days. These results suggest that dose response curve of biological reaction is remarkably affected by exposure

Environmental dioxin contamination in Chapaevsk, Russia: an evaluation of potential human health risks

Energy Technology Data Exchange (ETDEWEB)

Revich, B. [Center for Demography and Human Ecology of Inst. for Forecasting, Russian Academy of Sciences, Moscow (Russian Federation); Sergeyev, O. [Chapaevsk Medical Association, Chapaevsk (Russian Federation); Zeilert, V. [Central Medical Hospital, Chapaevsk (Russian Federation); Hauser, R. [Dept. of Environmental Health, Harvard School of Public Health, Boston (United States)

2004-09-15

The town of Chapaevsk (population 80 thousand) is located in Middle Volga region. During 1967- 1987 a chemical plant there produced hexachlorcyclohexan (lindan) and its derivatives. Later it produced crop protection chemicals (liquid chlorine, acids, methyl chloroform, vinyl chloride, and some other chemicals). Previously it was considered that hexachlorane production was responsible for dioxin contamination in the city's environment. Tests seemed to confirm it. But after the production was stopped in 1987, a continued output of dioxin was still observed. At present the plant stands practically idle; the main contamination source is represented by the old technological equipment, the plant's territory and industrial wastes. In 1994 an average concentration of dioxins in the air was 0.116 pg/m{sup 3}. The calculations were made when the plant worked at 20% capacity, so one can extrapolate that dioxin air emissions had been higher previously. Moving away from the plant one can see the decrease in dioxin levels down to 36.8 ng/kg in downtown (2.7 km from the plant); down to 3.9 ng/kg in the southern part of the city; down to 0.9 ng/kg at 10 - 15 km from the plant. Private house owners (18,000 in Chapaevsk) grow essentially all their vegetables and fruits for their own use, thus receiving an additional dioxin load. The results received in Chapaevsk boys study show a high proportion of the boys consumed locally grown or raised foods during their lifetime: over 70% consumed locally produced dairy products, over 50% consumed locally raised chickens or eggs, and over 80% consumed locally caught fish during their lifetime. In 1994 we began studies of dioxins impact on human health with the following aims: (1) to estimate dioxin levels in human blood and milk; (2) to estimate incidence and mortality rates, and specifically describe reproductive health in the population according to official statistical data; (3) to estimate dioxin exposure as a risk factor for

Evaluation of toxic equivalency factors for induction of cytochromes P450 CYP1A1 and CYP1A2 enzyme activity by dioxin-like compounds

International Nuclear Information System (INIS)

Toyoshiba, Hiroyoshi; Walker, Nigel J.; Bailer, A. John; Portier, Christopher J.

2004-01-01

The toxic equivalency factor (TEF) method has been used to characterize the toxicity of human mixtures of dioxin-like compounds and is being considered for use with other classes of potentially toxic agents. TEFs are estimated by examining the relative potencies of the various congeners for a series of biological and toxicological effects. In this paper, we consider changes in activity for two enzymes, cytochrome P450 1A1 (CYP1A1)-associated 7-ethoxyresorufin-O-deethylase (EROD) and CYP1A2-associated acetanilide-4-hydroxylase (A4H) activity, resulting from exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3',4,4',5-pentachlorobiphenyl (PCB), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF) or a mixture of these agents. The ratio of median effective dose (ED 50 ) is one way to estimate the relative potencies, especially for gene expression and protein endpoints. ED 50 's were estimated with a nonlinear regression model in which dose-related changes in mean responses are described by a Hill function. ED 50 's along with other model parameters were estimated by fitting this model to a given data set. Significant differences in estimated model parameters were tested by likelihood ratio methods. The estimated parameters indicated that congener-specific dose-response shapes were significantly different, that additivity failed for these congeners, and that the ratios of ED 50 's did not predict the response seen for the mixture. These results indicate that for some biological responses, the use of a single relative potency factor (RPF) is not appropriate for the comparison of the dose response behavior of different dioxin-like congeners

Low dose CT perfusion in acute ischemic stroke

Energy Technology Data Exchange (ETDEWEB)

Murphy, Amanda; Symons, Sean; Jakubovic, Raphael; Zhang, Liying; Aviv, Richard I. [Sunnybrook Health Sciences Centre, Toronto, ON (Canada); So, Aaron; Lee, Ting-Yim [Robarts Research Institute, London, Ontario (Canada)

2014-12-15

The purpose of this investigation is to determine if CT perfusion (CTP) measurements at low doses (LD = 20 or 50 mAs) are similar to those obtained at regular doses (RD = 100 mAs), with and without the addition of adaptive statistical iterative reconstruction (ASIR). A single-center, prospective study was performed in patients with acute ischemic stroke (n = 37; 54 % male; age = 74 ± 15 years). Two CTP scans were performed on each subject: one at 100 mAs (RD) and one at either 50 or 20 mAs (LD). CTP parameters were compared between the RD and LD scans in regions of ischemia, infarction, and normal tissue. Differences were determined using a within-subjects ANOVA (p < 0.05) followed by a paired t test post hoc analysis (p < 0.01). At 50 mAs, there was no significant difference between cerebral blood flow (CBF), cerebral blood volume (CBV), or time to maximum enhancement (Tmax) values for the RD and LD scans in the ischemic, infarcted, or normal contralateral regions (p < 0.05). At 20 mAs, there were significant differences between the RD and LD scans for all parameters in the ischemic and normal tissue regions (p > 0.05). CTP-derived CBF and CBV are not different at 50 mAs compared to 100 mAs, even without the addition of ASIR. Current CTP protocols can be modified to reduce the effective dose by 50 % without altering CTP measurements. (orig.)

PCB and dioxin levels in plasma and human milk of 418 Dutch women and their infants : predictive value of PCB congener levels in maternal plasma for fetal and infant's exposure to PCBs and dioxins

NARCIS (Netherlands)

Koopman-Esseboom, C.; Huisman, M.; Weisglas-Kuperus, N.; Paauw, C.G. van der; Tuinstra, L.G.M.T.; Boersma, E.R.; Sauer, P.J.J.

1995-01-01

Polychlorinated biphenyls (PCBs) as well as dioxins (polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs)) are potentially hazardous compounds in the environment for human beings. In order to investigate PCB and dioxin exposure of Dutch women and their neonates, levels were examined

PCB AND DIOXIN LEVELS IN PLASMA AND HUMAN-MILK OF 418 DUTCH WOMEN AND THEIR INFANTS - PREDICTIVE VALUE OF PCB CONGENER LEVELS IN MATERNAL PLASMA FOR FETAL AND INFANTS EXPOSURE TO PCBS AND DIOXINS

NARCIS (Netherlands)

KOOPMANESSEBOOM, C; HUISMAN, M; WEISGLASKUPERUS, N; VANDERPAAUW, CG; TUINSTRA, LGMT; BOERSMA, ER; SAUER, PJJ

Polychlorinated biphenyls (PCBs) as well as dioxins (polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs)) are potentially hazardous compounds in the environment for human beings. In order to investigate PCB and dioxin exposure of Dutch women and their neonates, levels were examined

Dioxin (TCDD induces epigenetic transgenerational inheritance of adult onset disease and sperm epimutations.

Directory of Open Access Journals (Sweden)

Mohan Manikkam

Full Text Available Environmental compounds can promote epigenetic transgenerational inheritance of adult-onset disease in subsequent generations following ancestral exposure during fetal gonadal sex determination. The current study examined the ability of dioxin (2,3,7,8-tetrachlorodibenzo[p]dioxin, TCDD to promote epigenetic transgenerational inheritance of disease and DNA methylation epimutations in sperm. Gestating F0 generation females were exposed to dioxin during fetal day 8 to 14 and adult-onset disease was evaluated in F1 and F3 generation rats. The incidences of total disease and multiple disease increased in F1 and F3 generations. Prostate disease, ovarian primordial follicle loss and polycystic ovary disease were increased in F1 generation dioxin lineage. Kidney disease in males, pubertal abnormalities in females, ovarian primordial follicle loss and polycystic ovary disease were increased in F3 generation dioxin lineage animals. Analysis of the F3 generation sperm epigenome identified 50 differentially DNA methylated regions (DMR in gene promoters. These DMR provide potential epigenetic biomarkers for transgenerational disease and ancestral environmental exposures. Observations demonstrate dioxin exposure of a gestating female promotes epigenetic transgenerational inheritance of adult onset disease and sperm epimutations.

Low dose radiation enhance the anti-tumor effect of high dose radiation on human glioma cell U251

International Nuclear Information System (INIS)

Wang Chang; Wang Guanjun; Tan Yehui; Jiang Hongyu; Li Wei

2008-01-01

Objective: To detect the effect on the growth of human glioma cell U251 induced by low dose irradiation and low dose irradiation combined with large dose irradiation. Methods: Human glioma cell line U251 and nude mice carried with human glioma were used. The tumor cells and the mice were treated with low dose, high dose, and low dose combined high dose radiation. Cells growth curve, MTT and flow cytometry were used to detect the proliferation, cell cycle and apoptosis of the cells; and the tumor inhibition rate was used to assess the growth of tumor in vivo. Results: After low dose irradiation, there was no difference between experimental group and control group in cell count, MTT and flow cytometry. Single high dose group and low dose combined high dose group both show significantly the suppressing effect on tumor cells, the apoptosis increased and there was cell cycle blocked in G 2 period, but there was no difference between two groups. In vivo apparent anti-tumor effect in high dose radiation group and the combining group was observed, and that was more significant in the combining group; the prior low dose radiation alleviated the injury of hematological system. There was no difference between single low dose radiation group and control. Conclusions: There is no significant effect on human glioma cell induced by low dose radiation, and low dose radiation could not induce adaptive response. But in vivo experience, low dose radiation could enhance the anti-tumor effect of high dose radiation and alleviated the injury of hematological system. (authors)

Detection of lung nodules with low-dose spiral CT: comparison with conventional dose CT

International Nuclear Information System (INIS)

Zhu Tianzhao; Tang Guangjian; Jiang Xuexiang

2004-01-01

Objective: To investigate the effect of reducing scan dose on the lung nodules detection rate by scanning a lung nodule model at low dose and conventional dose. Methods: The lung and the thoracic cage were simulated by using a cyst filled with water surrounded by a roll bandage. Flour, butter, and paraffin wax were mixed together by a certain ratio to simulate lung nodules of 10 mm and 5 mm in diameter with the CT values ranging from -10 to 50 HU. Conventional-dose scan (240 mA, 140 kV) and low-dose scan of three different levels (43 mA, 140 kV; 50 mA, 120 kV; 75 mA, 80 kV) together with three different pitches (1.0, 1.5, and 2.0) were performed. The images of the simulated nodules were combined with the CT images of a normal adult's upper, middle, and inferior lung. Three radiologists read the images and the number of the nodules they detected including both the real ones and the false-positive ones was calculated to investigate weather there was any difference among different doses, pitch groups, and different locations. Results: The detection rate of the 10 mm and 5 mm nodules was 100% and 89.6% respectively by the low-dose scan. There was no difference between low-dose and conventional-dose CT (χ 2 =0.6907, P>0.70). The detection rate of 5 mm nodules declined when large pitch was used. Conclusion: The detection rates of 10 mm and 5 mm nodules had no difference between low-dose CT and conventional-dose CT. As the pitch augmented, the detection rate for the nodules declined

Mutation process at low or high radiation doses

International Nuclear Information System (INIS)

Abrahamson, S.; Wisconsin Univ., Madison

1976-01-01

A concise review is given of the status of research on the genetic effects of low-level radiation in general. The term ''low dose'' is defined and current theories on low dose are set out. Problems and their solutions are discussed. (author)

''Low dose'' and/or ''high dose'' in radiation protection: A need to setting criteria for dose classification

International Nuclear Information System (INIS)

Sohrabi, M.

1997-01-01

The ''low dose'' and/or ''high dose'' of ionizing radiation are common terms widely used in radiation applications, radiation protection and radiobiology, and natural radiation environment. Reading the title, the papers of this interesting and highly important conference and the related literature, one can simply raise the question; ''What are the levels and/or criteria for defining a low dose or a high dose of ionizing radiation?''. This is due to the fact that the criteria for these terms and for dose levels between these two extreme quantities have not yet been set, so that the terms relatively lower doses or higher doses are usually applied. Therefore, setting criteria for classification of radiation doses in the above mentioned areas seems a vital need. The author while realizing the existing problems to achieve this important task, has made efforts in this paper to justify this need and has proposed some criteria, in particular for the classification of natural radiation areas, based on a system of dose limitation. (author)

A review of dioxin-related substances during municipal solid waste incineration.

Science.gov (United States)

Zhou, Hui; Meng, Aihong; Long, Yanqiu; Li, Qinghai; Zhang, Yanguo

2015-02-01

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) are among the most toxic chemicals and the main restriction on municipal solid waste incineration. To exert more effective control over the formation of dioxin homologues during municipal solid waste incineration, it is significant to investigate dioxin-related compounds. Despite the numerous studies about PCDD/Fs, a unified understanding regarding many problems has yet to be reached because the homologues of PCDD/Fs are excessive, the measurement of PCDD/Fs is difficult, and the formation mechanisms of PCDD/Fs are complicated. Firstly, this paper briefly introduces the different formation mechanisms of PCDD/Fs, including high temperature homogeneous reaction PCDD/Fs formation and low temperature heterogeneous reaction PCDD/Fs formation. Then the sources of PCDD/Fs including precursors (chlorophenols and polycyclic aromatic hydrocarbons) and residual carbon are summarized. In particular, this paper analyzes the substances that influence PCDD/Fs formation and their impact mechanisms, including different categories of chlorine (Cl2, HCl and chloride in fly ash), O2, copper, sulfur, water, and nitrogen compounds (ammonia and urea). Due to the high cost and complexity of PCDD/Fs measurement, PCDD/Fs indicators, especially chlorobenzenes and polycyclic aromatic hydrocarbons, are summarized, to find an effective surrogate for quick, convenient and real-time monitoring of PCDD/Fs. Finally, according to the results of the current study, recommendations for further research and industrial applications prospects are proposed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Biological effects of low-dose ionizing radiation exposure

International Nuclear Information System (INIS)

Reinoehl-Kompa, Sabine; Baldauf, Daniela; Heller, Horst

2009-01-01

The report on the meeting of the Strahlenschutzkommission 2007 concerning biological effects of low-dose ionizing radiation exposure includes the following contributions: Adaptive response. The importance of DNA damage mechanisms for the biological efficiency of low-energy photons. Radiation effects in mammography: the relative biological radiation effects of low-energy photons. Radiation-induced cataracts. Carcinomas following prenatal radiation exposure. Intercellular apoptosis induction and low-dose irradiation: possible consequences for the oncogenesis control. Mechanistic models for the carcinogenesis with radiation-induced cell inactivation: application to all solid tumors in the Japanese atomic bomb survivors. Microarrays at low radiation doses. Mouse models for the analysis of biological effects of low-dose ionizing radiation. The bystander effect: observations, mechanisms and implications. Lung carcinoma risk of Majak workers - modeling of carcinogenesis and the bystander effect. Microbeam studies in radiation biology - an overview. Carcinogenesis models with radiation-induced genomic instability. Application to two epidemiological cohorts.

Prolonged endoplasmic reticulum stress alters placental morphology and causes low birth weight

International Nuclear Information System (INIS)

Kawakami, Takashige; Yoshimi, Masaki; Kadota, Yoshito; Inoue, Masahisa; Sato, Masao; Suzuki, Shinya

2014-01-01

The role of endoplasmic reticulum (ER) stress in pregnancy remains largely unknown. Pregnant mice were subcutaneously administered tunicamycin (Tun), an ER stressor, as a single dose [0, 50, and 100 μg Tun/kg/body weight (BW)] on gestation days (GDs) 8.5, 12.5, and 15.5. A high incidence (75%) of preterm delivery was observed only in the group treated with Tun 100 μg/kg BW at GD 15.5, indicating that pregnant mice during late gestation are more susceptible to ER stress on preterm delivery. We further examined whether prolonged in utero exposure to ER stress affects fetal development. Pregnant mice were subcutaneously administered a dose of 0, 20, 40, and 60 μg Tun/kg from GD 12.5 to 16.5. Tun treatment decreased the placental and fetal weights in a dose-dependent manner. Histological evaluation showed the formation of a cluster of spongiotrophoblast cells in the labyrinth zone of the placenta of Tun-treated mice. The glycogen content of the fetal liver and placenta from Tun-treated mice was lower than that from control mice. Tun treatment decreased mRNA expression of Slc2a1/glucose transporter 1 (GLUT1), which is a major transporter for glucose, but increased placental mRNA levels of Slc2a3/GLUT3. Moreover, maternal exposure to Tun resulted in a decrease in vascular endothelial growth factor receptor-1 (VEGFR-1), VEGFR-2, and placental growth factor. These results suggest that excessive and exogenous ER stress may induce functional abnormalities in the placenta, at least in part, with altered GLUT and vascular-related gene expression, resulting in low infant birth weight. - Highlights: • Maternal exposure to excessive ER stress induced preterm birth and IUGR. • Prolonged excessive ER stress altered the formation of the placental labyrinth. • ER stress decreased GLUT1 mRNA expression in the placenta, but increased GLUT3. • ER stress-induced IUGR causes decreased glycogen and altered glucose transport

Prolonged endoplasmic reticulum stress alters placental morphology and causes low birth weight

Energy Technology Data Exchange (ETDEWEB)

Kawakami, Takashige, E-mail: tkawakami@ph.bunri-u.ac.jp; Yoshimi, Masaki; Kadota, Yoshito; Inoue, Masahisa; Sato, Masao; Suzuki, Shinya

2014-03-01

The role of endoplasmic reticulum (ER) stress in pregnancy remains largely unknown. Pregnant mice were subcutaneously administered tunicamycin (Tun), an ER stressor, as a single dose [0, 50, and 100 μg Tun/kg/body weight (BW)] on gestation days (GDs) 8.5, 12.5, and 15.5. A high incidence (75%) of preterm delivery was observed only in the group treated with Tun 100 μg/kg BW at GD 15.5, indicating that pregnant mice during late gestation are more susceptible to ER stress on preterm delivery. We further examined whether prolonged in utero exposure to ER stress affects fetal development. Pregnant mice were subcutaneously administered a dose of 0, 20, 40, and 60 μg Tun/kg from GD 12.5 to 16.5. Tun treatment decreased the placental and fetal weights in a dose-dependent manner. Histological evaluation showed the formation of a cluster of spongiotrophoblast cells in the labyrinth zone of the placenta of Tun-treated mice. The glycogen content of the fetal liver and placenta from Tun-treated mice was lower than that from control mice. Tun treatment decreased mRNA expression of Slc2a1/glucose transporter 1 (GLUT1), which is a major transporter for glucose, but increased placental mRNA levels of Slc2a3/GLUT3. Moreover, maternal exposure to Tun resulted in a decrease in vascular endothelial growth factor receptor-1 (VEGFR-1), VEGFR-2, and placental growth factor. These results suggest that excessive and exogenous ER stress may induce functional abnormalities in the placenta, at least in part, with altered GLUT and vascular-related gene expression, resulting in low infant birth weight. - Highlights: • Maternal exposure to excessive ER stress induced preterm birth and IUGR. • Prolonged excessive ER stress altered the formation of the placental labyrinth. • ER stress decreased GLUT1 mRNA expression in the placenta, but increased GLUT3. • ER stress-induced IUGR causes decreased glycogen and altered glucose transport.

Comparison of hyperuricemia in type 2 diabetics on low dose aspirin and not on low dose aspirin

International Nuclear Information System (INIS)

Malik, M.I.

2013-01-01

Objective: To compare the frequency of hyperuricemia in type 2 diabetes patients who are taking low dose aspirin with those patients who are not taking low dose aspirin. Study design: Quasi experimental study. Place and duration of study: This study was carried out at Military Hospital Rawalpindi for a period of two years (June 2006-May 2008). Patients and Methods: Sixty diabetic patients were selected who were taking low dose aspirin comparing group A and sixty diabetic patients who were not taking aspirin were placed in group B. These patients were selected from the OPD through non probability convenience sampling. All these patients were being followed up in medical outpatient quite regularly on fort-nightly basis. Data had been collected through a carefully designed questionnaire. Results: In group A, 90% of the patients had uric acid less than 445 micro mol/l and 10% of the patients had uric acid more than 445micro mol/l. Whereas in group B 100% of the patients had uric acid less than 445umol/l, there was a statistically significant difference between the two groups (p< 0.05). Conclusion: Aspirin in low doses cause hyperuricemia and regular monitoring of uric acid is mandatory to prevent its adverse effects. (author)

Hydrothermal treatment of municipal solid waste incineration fly ash for dioxin decomposition

International Nuclear Information System (INIS)

Hu, Yuyan; Zhang, Pengfei; Chen, Dezhen; Zhou, Bin; Li, Jianyi; Li, Xian-wei

2012-01-01

Highlights: ► The first study to apply Fe-sulfate in hydrothermal treatment of municipal solid waste incineration fly ash for dioxin decomposition. ► The first study to comprehensively evaluate the effect of hydrothermal treatment on dioxin decomposition and heavy metal stabilization in municipal solid waste incineration fly ash. ► Gaussian software chemical computational simulation was performed to investigate the mechanism of dioxin decomposition based on quantum chemistry calculation, and to support the experimental data by the calculation results. - Abstract: Hydrothermal treatment of MSWI fly ash was performed in this paper with a purpose to reduce its dioxin content. First a hydrothermal reactor was set up with a mixture of ferric sulphate and ferrous sulphate serviced as the reactant, then the effects caused by reaction conditions such as reaction temperature, pre-treatment by water-washing and reactant dosage were checked; the results showed that as a promising technology, hydrothermal treatment exhibited considerable high efficiencies in decomposition of PCDDs/PCDFs and good stabilization of heavy metals as well. Experimental results also showed that for dioxin destruction, higher reaction temperature is the most important influencing factor followed by Fe addition, and pre-treatment of raw fly ash by water-washing increased the destruction efficiencies of dioxins only very slightly. Finally with help of Gaussian software chemical computational simulation was performed to investigate the mechanism of dioxin decomposition based on quantum chemistry calculation. The calculation results were supported by the experimental data. The leaching toxicities of hydrothermal products were higher than upper limits defined in the latest Chinese standard GB 16889-2008 for sanitary landfill disposal, thus an auxiliary process is suggested after the hydrothermal treatment for heavy metal stabilization.

Enhancing the response of CALUX and CAFLUX cell bioassays for quantitative detection of dioxin-like compounds

Science.gov (United States)

ZHAO, Bin; BASTON, David S.; KHAN, Elaine; SORRENTINO, Claudio; DENISON, Michael S.

2011-01-01

Reporter genes produce a protein product in transfected cells that can be easily measured in intact or lysed cells and they have been extensively used in numerous basic and applied research applications. Over the past 10 years, reporter gene assays have been widely accepted and used for analysis of 2,3,7,8-tetrachlorodibenzo-p-dioxin and related dioxin-like compounds in various types of matrices, such as biological, environmental, food and feed samples, given that high-resolution instrumental analysis techniques are impractical for large-scale screening analysis. The most sensitive cell-based reporter gene bioassay systems developed are the mechanism-based CALUX (Chemically Activated Luciferase Expression) and CAFLUX (Chemically Activated Fluorescent Expression) bioassays, which utilize recombinant cell lines containing stably transfected dioxin (AhR)-responsive firefly luciferase or enhanced green fluorescent protein (EGFP) reporter genes, respectively. While the current CALUX and CAFLUX bioassays are very sensitive, increasing their lower limit of sensitivity, magnitude of response and dynamic range for chemical detection would significantly increase their utility, particularly for those samples that contain low levels of dioxin-like HAHs (i.e., serum). In this study, we report that the addition of modulators of cell signaling pathways or modification of cell culture conditions results in significant improvement in the magnitude and overall responsiveness of the existing CALUX and CAFLUX cell bioassays. PMID:21394221

Charophyte electrogenesis as a biomarker for assessing the risk from low-dose ionizing radiation to a single plant cell

International Nuclear Information System (INIS)

Sevriukova, Olga; Kanapeckaite, Auste; Lapeikaite, Indre; Kisnieriene, Vilma; Ladygiene, Rima; Sakalauskas, Vidmantas

2014-01-01

The impact of low-dose ionizing radiation on the electrical signalling pattern and membrane properties of the characea Nitellopsis obtusa was examined using conventional glass-microelectrode and voltage-clamp techniques. The giant cell was exposed to a ubiquitous radionuclide of high biological importance – tritium – for low-dose irradiation. Tritium was applied as tritiated water with an activity concentration of 15 kBq L −1 (an external dose rate that is approximately 0.05 μGy h −1 above the background radiation level); experiments indicated that this was the lowest effective concentration. Investigating the dynamics of electrical excitation of the plasma membrane (action potential) showed that exposing Characeae to tritium for half an hour prolonged the repolarization phase of the action potential by approximately 35%: the repolarization rate decreased from 39.2 ± 3.1 mV s −1 to 25.5 ± 1,8 mV s −1 due to tritium. Voltage-clamp measurements showed that the tritium exposure decreased the Cl – efflux and Ca 2+ influx involved in generating an action potential by approximately 27% (Δ = 12.4 ± 1.1 μA cm −2 ) and 64% (Δ = −5.3 ± 0.4 μA cm −2 ), respectively. The measured alterations in the action potential dynamics and in the chloride and calcium ion transport due to the exogenous low-dose tritium exposure provide the basis for predicting possible further impairments of plasma membrane regulatory functions, which subsequently disturb essential physiological processes of the plant cell. - Highlights: • We show some cellular details of the impact of low-dose ionizing radiation on biota. • Giant green algae cells provides a useful tool for studying HTO toxicity to a single plant cell. • Rapid real-time electrophysiological methods allowed to determine low dose tritium effect on transmembrane ion fluxes. • Pattern of charophyte cell membrane electrical excitation encodes tritium-caused alteration in cell homeostasis

Health related war dioxin in Vietnam today, methodological approach in evaluation

Energy Technology Data Exchange (ETDEWEB)

Thom, Le Hong; Tran, Manh Hung; Phung, Tri Dung [Ministry of Health, Ha Noi (Viet Nam)

2004-09-15

The Chemical war, that lasted for more than 10 years (1961-1971) had ended 30 years ago, but its severe outcomes on exposed human health seem to be far from ending. By the newest calculations, there should be more than 80 million of herbicides, including no less than 500 kg of Dioxin - 2,3,7,8-TCDD have been sprayed over land of South Vietnam. Dioxin the most ecotoxic agent, that human knowns to now, and have been researched by many scientists over the world. The studies conducted in experimental animals and partly in human tissues, have demonstrated, that dioxin cause the toxicity for many biofunctions, especially for systems like: nervous, digestive, immunoresponses, reproductive health, skin disorders, and carcinogenicity. It seems to be, that Viet nam have become a ''biggest laboratory'' of dioxin testing and its effects studying over the world. Many research into human health have been done, but the opinions of health outcomes, related to dioxin exposure still cause the debates. A lot of studies conducted on nature and man in Viet nam also, unfortunately there is not yet the overview general, concerning the methodological as epidemiological criteria. This report sum up the health, especially the reproductive outcomes, based strictly on the epidemiological disciplines.

Low dose radiation exposure and atherosclerosis in ApoE{sup -/-} mice

Energy Technology Data Exchange (ETDEWEB)

Mitchel, R.E.J. [Atomic Energy of Canada Limited, Chalk River, ON (Canada); Hasu, M. [Univ. of Ottawa, Department of Pathology and Lab. Medicine, and Cellular and Molecular Medicine, Ottawa, ON (Canada); Univ. of Ottawa Heart Inst., Vascular Biology Group, Ottawa, ON (Canada); Bugden, M.; Wyatt, H. [Atomic Energy of Canada Limited, Chalk River, ON (Canada); Little, M. [Imperial Coll., Faculty of Medicine, St. Marys Campus, London (United Kingdom); Hildebrandt, G. [Univ. Hospital, Dept. of Radiotherapy, Rostock (Germany); Priest, N.D. [Atomic Energy of Canada Limited, Chalk River, ON (Canada); Whitman, S.C. [Univ. of Ottawa, Department of Pathology and Lab. Medicine, and Cellular and Molecular Medicine, Ottawa, ON (Canada); Univ. of Ottawa Heart Inst., Vascular Biology Group, Ottawa, ON (Canada)

2010-07-01

The hypothesis that single low dose exposures (0.025-0.5 Gy) to low LET radiation, given at either high (240 mGy/min) or low (1 mGy/min) dose rate, would promote aortic atherosclerosis was tested in female C57BI/6 mice genetically predisposed to this disease (ApoE-/-). Mice were exposed either at early stage disease (2 months of age) and examined 3 or 6 months later, or at late stage disease (8 months of age) and examined 2 or 4 months later. Compared to unexposed controls, all doses given at low or high dose rate at early stage disease had significant inhibitory effects on lesion growth and, at 25 or 50 mGy, on lesion frequency. No dose given at low dose rate had any effect on total serum cholesterol, but this was elevated by every dose given at high dose rate. Exposures at low dose rate had no effect on the percentage of lesion lipids contained within macrophages, and, at either high or low dose rate, had no significant effect on lesion severity. Exposure at late stage disease, to any dose at high dose rate, had no significant effect on lesion frequency, but at low dose rate some doses produced a small transient increase in this frequency. Exposure to low doses at low, but not high dose rate, significantly, but transiently reduced average lesion size, and at either dose rate transiently reduced lesion severity. Exposure to any dose at low dose rate (but not high dose rate) resulted in large and persistent decreases in serum cholesterol. These data indicate that a single low dose exposure, depending on dose and dose rate, generally protects against various measures of atherosclerosis in genetically susceptible mice. This result contrasts with the known, generally detrimental effects of high doses on this disease in the same mice, suggesting that a linear extrapolation of risk from high doses is not appropriate. (author)

Regulatory aspects of low doses control in Albania

International Nuclear Information System (INIS)

Dollani, K.; Kushe, R.

1997-01-01

In the present paper are described the status of regulatory aspects of low doses control as well as the existing procedures for their implementation in Albania. According to new Radiological Protection Act, approved by Parliament in 1995, the establishment of the infrastructures in radiation protection area is in course, accompanied by the installation and functioning of new equipment for low dose control. Based in many years experience it is concluded that personal doses of the workers added by practices in Albania are 1/10 of dose Emits. Some particular cases of overexposured workers were investigated. Last times the elements of the optimisation procedures (QA and QC) are outlined in the frame of improving regulatory aspects of low doses control. (author)

Exposure to low doses of ionizing radiations

International Nuclear Information System (INIS)

Le Guen, B.

2008-01-01

The author discusses the knowledge about the effects of ionizing radiations on mankind. Some of them have been well documented (skin cancer and leukaemia for the pioneer scientists who worked on radiations, some other types of cancer for workers who handled luminescent paints, rock miners, nuclear explosion survivors, patients submitted to radiological treatments). He also evokes the issue of hereditary cancers, and discusses the issue of low dose irradiation where some surveys can now be performed on workers. He discusses the biological effects of these low doses. He outlines that many questions remain about these effects, notably the influence of dose level and of dose rate level on the biological reaction

Dioxins: diagnostic and prognostic challenges arising from complex mechanisms

DEFF Research Database (Denmark)

Rysavy, Noel M.; Maaetoft-Udsen, Kristina; Turner, Helen

2013-01-01

Dioxins are ubiquitous environmental challenges to humans, with a pervasiveness that arises from 200?years of rapid industrialization and mechanization of Western societies and which is now extending into the developing world. In spite of their penetrance of the human biota, these compounds...... such as cancer and diabetes, which are already multifactorial and highly complex, creates the context for the current review paper. Here, we summarize dioxin exposure paradigms and the resulting physiological effects that have been documented in animals and humans. Novel insights into potential endogenous end...... exogenous ligands, as well as the mechanisms by which these ligands impact acute and chronic cellular processes, are discussed. We develop the idea that the diagnosis of dioxin exposure, the subtleties of the cellular effects of the compounds and prognosis of the long-term effects of exposure are problems...

Bioavailability of diclofenac potassium at low doses

Science.gov (United States)

Hinz, Burkhard; Chevts, Julia; Renner, Bertold; Wuttke, Henrike; Rau, Thomas; Schmidt, Andreas; Szelenyi, Istvan; Brune, Kay; Werner, Ulrike

2005-01-01

Aim Diclofenac-K has been recently launched at low oral doses in different countries for over-the-counter use. However, given the considerable first-pass metabolism of diclofenac, the degree of absorption of diclofenac-K at low doses remained to be determined. The aim of this study was to determine the bioavailability of low-dose diclofenac-K. Methods A randomized, three-way, cross-over study was performed in 10 subjects. Each received diclofenac-K, 22.5 mg via short-term i.v. infusion and orally at single doses of 12.5 mg and 25 mg. Results Mean (± SD) times to maximal plasma concentration (tmax) of diclofenac were 0.48 ± 0.28 h (12.5 mg) and 0.93 ± 0.96 h (25 mg). The absolute bioavailability of diclofenac-K after oral administration did not differ significantly in the 12.5-mg and 25-mg dose group (63.1 ± 12.6% vs. 65.1 ± 19.4%, respectively). The 90% confidence intervals for the AUC∞ and AUCt ratios for the two oral regimes were 82.6, 103.4% (point estimate 92.4%) and 86.2, 112.9% (point estimate 98.6%), respectively. These values were within the acceptance criteria for bioequivalence (80–125%). Conclusions Our data indicate that diclofenac-K is rapidly and well absorbed at low dose, and are consistent with a rapid onset of action of the drug. Abbreviations AUC, area under plasma concentraton-time curve; Cmax, peak plasma concentration; CI, confidence interval; COX, cyclooxygenase; D, dose; F, absolute bioavailability; tmax, time to reach Cmax. PMID:15606444

Antagonistic effects of gestational dietary exposure to low-dose vinclozolin and genistein on rat fetal germ cell development.

Science.gov (United States)

Lehraiki, Abdelali; Messiaen, Sébastien; Berges, Raymond; Canivenc-Lavier, Marie-Chantal; Auger, Jacques; Habert, René; Levacher, Christine

2011-05-01

Continuous, low-dose exposure to a phytoestrogen (1 mg/kg/day genistein) and/or to an antiandrogenic food contaminant (1 mg/kg/day vinclozolin) has been recently reported to affect male reproductive tract and fertility [1] in adults. We investigated whether alterations of the testis are already present at the end of in utero exposure using the same rat model and doses following exposure from conception to delivery. After vinclozolin exposure, we observed in the neonate a slight but significant alteration of steroidogenesis and gametogenesis with a reduction of testosterone secretion and of the number of gonocytes. In contrast, genistein exposure had no effect. While the vinclozolin-genistein mixture acts in a synergistic manner to induce the most significant alterations in the adult, interestingly, genistein antagonized the deleterious effect of vinclozolin on germ cells in the neonate. This difference emphasizes the importance of studying the effects of endocrine disruptors during various developmental stages to understand their effects. Copyright © 2011 Elsevier Inc. All rights reserved.

Carcinogenesis in mice after low doses and dose rates

International Nuclear Information System (INIS)

Ullrich, R.L.

1979-01-01

The results from the experimental systems reported here indicate that the dose-response curves for tumor induction in various tissues cannot be described by a single model. Furthermore, although the understanding of the mechanisms involved in different systems is incomplete, it is clear that very different mechanisms for induction are involved. For some tumors the mechanism of carcinogenesis may be mainly a result of direct effects on the target cell, perhaps involving one or more mutations. While induction may occur, in many instances, through such direct effects, the eventual expression of the tumor can be influenced by a variety of host factors including endocrine status, competence of the immune system, and kinetics of target and interacting cell populations. In other tumors, indirect effects may play a major role in the initiation or expression of tumors. Some of the hormone-modulated tumors would fall into this class. Despite the complexities of the experimental systems and the lack of understanding of the types of mechanisms involved, in nearly every example the tumorigenic effectiveness per rad of low-LET radiation tends to decrease with decreasing dose rate. For some tumor types the differences may be small or may appear only with very low dose rates, while for others the dose-rate effects may be large

Some remarks on the significance of low doses

International Nuclear Information System (INIS)

Cigna, A.A.

1989-12-01

The criteria of the present system of individual dose limitation are considered as well as the evolution of the limiting values. The assumption of the linearity of the dose-effect relationship without any threshold is probably the best approach to adopt for recommendations in radiation protection and for accounting the doses acquired by exposure to ionizing radiation. On the other hand the present evaluation of the natural background could imply a different dose-effect relationship in the low doses region and perhaps the existence of a threshold. Therefore the extrapolations which are usually made after exposures of different groups of people to low doses cannot be considered as scientifically sound. (author)

Mutation induction in cultured human cells after low-dose and low-dose-rate γ-ray irradiation. Detection by LOH analysis

International Nuclear Information System (INIS)

Umebayashi, Yukihiro; Iwaki, Masaya; Yatagai, Fumio; Honma, Masamitsu; Suzuki, Masao; Suzuki, Hiromi; Shimazu, Toru; Ishioka, Noriaki

2007-01-01

To study the genetic effects of low-doses and low-dose-rate ionizing radiation (IR), human lymphoblastoid TK6 cells were exposed to 30 mGy of γ-rays at a dose-rate of 1.2 mGy/hr. The frequency of early mutations (EMs) in the thymidine kinase (TK) gene locus was determined to be 1.7 x 10 -6 , or 1.9-fold higher than the level seen in unirradiated controls. These mutations were analyzed with a loss of heterozygosity (LOH) detection system, a methodology which has been shown to be sensitive to the effects of radiation. Among the 15 EMs observed after IR exposure, 8 were small interstitial-deletion events restricted to the TK gene locus. However, this specific type of event was not found in unirradiated controls. Although these results were observed under the limited conditions, they strongly suggest that the LOH detection system can be used for estimating the genetic effects of a low-dose IR exposure delivered at a low-dose-rate. (author)

Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on estrogenic responses

Energy Technology Data Exchange (ETDEWEB)

Romkes, M.

1988-01-01

The competitive receptor binding affinities of thirteen 2-substituted-3,7,8-trichlorodibenzo-p-dioxins to hepatic cytosol from rat, mouse, guinea pig and hamster were determined using ({sup 3}H)-2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) as the radio-ligand. Significant species-dependent structural differences in the Ah receptor ligand binding site were observed and support the heterologous nature of the receptor protein. The interactions of 2,3,7,8-TCDD and estrogenic responses in the female rat and human breast cancer cells were also investigated. Cotreatment of 25-day-old female Long Evans rats with 20 or 80 ug/kg of 2,3,7,8-TCDD resulted in a dose-dependent decrease in both uterine and hepatic estrogen receptor (ER) levels. Moreover, these levels are decreased for at least ten days and appear to be related to the tissue persistence of 2,3,7,8-TCDD. In contrast, estradiol elevated uterine and hepatic ER levels and increased uterine wet weights. Cotreatment of the rats with 2,3,7,8-TCDD and estradiol resulted in hepatic and uterine ER levels which were comparable to those observed in the control rats; in addition, 2,3,7,8-TCDD also antagonized the effects of estradiol-induced uterine wet weights.

Documents for Recommended Toxicity Equivalency Factors for Human Health Risk Assessments of Dioxin and Dioxin-Like Compounds

Science.gov (United States)

This document describes the U.S. Environmental Protection Agency’s (U.S. EPA’s) updated approach for evaluating the human health risks from exposures to environmental media containing dioxin-like compounds (DLCs).

Perinatal dioxin exposure and psychosocial and behavioral development in school-aged children.

Science.gov (United States)

Kono, Yumi; Oka, Akira; Tada, Hiroshi; Itabashi, Kazuo; Matsui, Eiko; Nakamura, Yosikazu

2015-09-01

The aim of this study was to elucidate the association between psychosocial and behavioral problems in children at school age and dioxin level in breast milk or estimated dioxin exposure (EDE) through breastfeeding in the general Japanese population. Dioxin level of breast milk at 1month of age and breastfeeding ratio through the first year of life were used to calculate the EDE of infants born in 1998-2005 in Japan. The Japanese Social Difficulties Questionnaire (SDQ) for the assessment of children's behavior was sent by mail to mothers whose breast milk underwent the dioxin survey, at the time when their infants were aged 6-13 years. The study subjects were 175 pairs of mothers and their first infants (79 boys, 96 girls). The mean total dioxin levels of breast milk were 18.3 and 19.8 (pgTEQ/g fat) and EDEs were 16.4 and 19.6 (ngTEQ/kg/year) in boys and girls, respectively. In linear multiple regression analyses after adjusting for age at SDQ, maternal age, birth weight and maternal smoking habit, dioxin level in breast milk was not significantly related to the total difficulties score (TDS) of SDQ in boys, B=2.29 (95% CI -7.60-12.18), or in girls, B=-1.04 (95% CI -9.24-7.15). EDE correlated to the TDS in neither boys, B=-0.99 (95% CI -4.14-2.15), nor girls, B=1.08 (95% CI -2.69-4.85). No evidence was found of a correlation between perinatal dioxin exposure and behavioral and psychosocial problems of children measured by SDQ. These results support the benefits of recommending breastfeeding. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Impact of low-dose chronic exposure to Bisphenol A (BPA) on adult male zebrafish adaption to the environmental complexity: Disturbing the color preference patterns and reliving the anxiety behavior.

Science.gov (United States)

Li, Xiang; Sun, Ming-Zhu; Li, Xu; Zhang, Shu-Hui; Dai, Liang-Ti; Liu, Xing-Yu; Zhao, Xin; Chen, Dong-Yan; Feng, Xi-Zeng

2017-11-01

The extensive usage of xenobiotic endocrine disrupting chemicals (XEDCs), such as Bisphenol A (BPA), has created obvious threat to aquatic ecosystems worldwide. Although a comprehensive understanding of the adverse effect of BPA on behaviors and physiology have been proven, the potential impact of low-dose BPA on altering the basic ability of aquatic organism in adapting to the surrounded complex environment still remains elusive. In this research, we report that treatment of adult male zebrafish with chronic (7 weeks) low-dose (0.22 nM-2.2 nM) BPA, altered the ability in adapting the complex environment by disturbing the natural color preference patterns. In addition, chronic 50 ng/L (0.22 nM) BPA exposure alleviated the anxiety behavior of male zebrafish confronted with the novel environment by enhancing the preference towards light in the light/dark preference test. This phenotype was associated with less expression of serotonin (5-TH) in the hypothalamus and the down-regulation of tyrosine hydroxylase (TH) in brain tissues. As such, our results show that low-dose BPA remnant in surface waters altered zebrafish behavior that are known to have ecological and evolutionary consequences. Here we reported that the impact of chronic low-dose BPA exposure on the basic capability of zebrafish to adapt to the environmental complexity. Specifically, BPA at low concentration, under the environmental safety level and 3000-fold lower than the accepted human daily exposure, interfered with the ability to discriminate color and alleviate anxiety induced by the novel environment, which finally altered the capability of male zebrafish to adapt to the environmental complexity. These findings revealed the ecological effect of low-dose BPA and regular BPA concentration standard are not necessarily safe. The result also provided the consideration of retuning the hazard concentration level of BPA. Copyright © 2017 Elsevier Ltd. All rights reserved.

Deep learning for low-dose CT

Science.gov (United States)

Chen, Hu; Zhang, Yi; Zhou, Jiliu; Wang, Ge

2017-09-01

Given the potential risk of X-ray radiation to the patient, low-dose CT has attracted a considerable interest in the medical imaging field. Currently, the main stream low-dose CT methods include vendor-specific sinogram domain filtration and iterative reconstruction algorithms, but they need to access raw data whose formats are not transparent to most users. Due to the difficulty of modeling the statistical characteristics in the image domain, the existing methods for directly processing reconstructed images cannot eliminate image noise very well while keeping structural details. Inspired by the idea of deep learning, here we combine the autoencoder, deconvolution network, and shortcut connections into the residual encoder-decoder convolutional neural network (RED-CNN) for low-dose CT imaging. After patch-based training, the proposed RED-CNN achieves a competitive performance relative to the-state-of-art methods. Especially, our method has been favorably evaluated in terms of noise suppression and structural preservation.

Concentration and distribution of dioxins and related compounds in various human organs

Energy Technology Data Exchange (ETDEWEB)

Iida, T.; Hirakawa, H.; Hori, T.; Tobiishi, K.; Matsueda, T. [Fukuoka Inst. of Health and Environmental Sciences, Dazaifu, Fukuoka (Japan); Todaka, T. [Japan Food Hygiene Association, Tokyo (Japan); Watanabe, S. [Tokyo Univ. of Agriculture, Tokyo (Japan); Yamada, T. [Keio Univ. School of Medicine, Tokyo (Japan)

2004-09-15

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and non-ortho coplanar polychlorinated biphenyls (Non-Co-PCBs) and mono-ortho coplanar polychlorinated biphenyls (Mono-Co-PCBs) accumulate in the human body due to their highly lipophilic properties. In recent years, there has been some concern about the potential health effects of dioxins and related chemicals for the general population of humans. Although there exists an enormous amount of data on this subject, most of it is from breast milk and blood, due to ease of collection; information concerning concentrations and distribution in various human organs hardly exists. Therefore, new data concerning various human tissues is required to evaluate the pathophysiological significance of dioxins and related compounds in humans. The aim of this study was to investigate the concentration levels and distribution of dioxins and related compounds in various human organ tissues. We previously reported on the concentration levels in the human liver and adipose tissues from 28 donors. In this paper, we determined the concentrations of dioxin-like isomers in 8 organs, including blood, lungs, liver, bile, spleen, pancreas, kidney and mesentery fat from 20 donors.

Curbing dioxin emissions from municipal solid waste incineration in China: Re-thinking about management policies and practices

Energy Technology Data Exchange (ETDEWEB)

Cheng Hefa, E-mail: hefac@umich.ed [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Hu Yuanan [Education Program for Gifted Youth, Stanford University, Stanford, CA 94025 (United States)

2010-09-15

As one of the countries with large amounts of dioxin releases, the control of dioxins is a major challenge for China. Municipal solid waste (MSW) incineration should be considered a high priority source of dioxin emissions because it is playing an increasingly more important role in waste management. MSW incineration in China has much higher emission rates of dioxins than in the developed countries, partially resulting from the gaps in the technologies of incineration and flue gas cleaning. Moreover, the current management policies and practices also contribute significantly to the problem. We recommend lowering dioxin emission standard, strengthening fly ash management, and improving regulation enforcement to reduce dioxin releases into the environment from MSW incineration. We also propose that alternative strategies should be considered on dioxin control and call for an expansion of economic instruments in waste management to reduce waste generation and thus the need for incineration. - The management policies and practices need to be improved to curb the increasing dioxin releases from municipal solid waste incineration in China.

Curbing dioxin emissions from municipal solid waste incineration in China: Re-thinking about management policies and practices

International Nuclear Information System (INIS)

Cheng Hefa; Hu Yuanan

2010-01-01

As one of the countries with large amounts of dioxin releases, the control of dioxins is a major challenge for China. Municipal solid waste (MSW) incineration should be considered a high priority source of dioxin emissions because it is playing an increasingly more important role in waste management. MSW incineration in China has much higher emission rates of dioxins than in the developed countries, partially resulting from the gaps in the technologies of incineration and flue gas cleaning. Moreover, the current management policies and practices also contribute significantly to the problem. We recommend lowering dioxin emission standard, strengthening fly ash management, and improving regulation enforcement to reduce dioxin releases into the environment from MSW incineration. We also propose that alternative strategies should be considered on dioxin control and call for an expansion of economic instruments in waste management to reduce waste generation and thus the need for incineration. - The management policies and practices need to be improved to curb the increasing dioxin releases from municipal solid waste incineration in China.

Assessment of low absorbed dose with a MOSFET detector

International Nuclear Information System (INIS)

Butson, M.J.; Cancer Services, Wollongong, NSW; Cheung, T.; Yu, P.K.N.

2004-01-01

Full text: The ability of a MOSFET dosimetry system to measure low therapeutic doses has been evaluated for accuracy for high energy x-ray radiotherapy applications. The MOSFET system in high sensitivity mode produces a dose measurement reproducibility of within 10%, 4% and 2.5% for 2 cGy, 5 cGy and 10cGy dose assessment respectively. This is compared to 7%, 4% and 2% for an Attix parallel plate ionisation chamber and 20%, 7% and 3.5% for a Wellhofer IC4 small volume ionisation chamber. Results for our dose standard thimble ionisation chamber and low noise farmer dosemeter were 2%, 0.5% and 0.25% respectively for these measurements. The quoted accuracy of the MOSFET dosimetry system is partially due to the slight non linear dose response (reduced response) with age of the detector but mainly due to the intrinsic variations in measured voltage differential per applied dose. Results have shown that the MOSFET dosimetry system provides an adequate measure of dose at low dose levels and is comparable in accuracy to the Attix parallel plate ionisation chambers for relative dose assessment at levels of 2cGy to 10cGy. The use of the MOSFET dosimeter at low doses can extend the life expectancy of the device and may provide useful information for areas where low dose assessment is required. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

Low dose epidemiology

International Nuclear Information System (INIS)

Tirmarche, M.; Hubert, P.

1992-01-01

Actually, epidemiological studies have to establish if the assessment of cancer risk can be verified at low chronic radiation doses. The population surveillance must be very long, the side effects and cancers of such radiation appearing much later. In France, this epidemiological study on nuclear workers have been decided recently. Before describing the experiment and french projects in epidemiology of nuclear workers, the authors present the main english and american studies

Inhalation Exposure to Dioxins and dl-PCBs Depending on the Season in Upper Silesia, Poland: A Pilot Study.

Science.gov (United States)

Dziubanek, Grzegorz; Marchwińska, Ewa; Hajok, Ilona; Piekut, Agata

2016-06-01

The aim of this study was to investigate the seasonal fluctuation of PCDD/Fs and dl-PCBs levels in the ambient air of Upper Silesia in the aspect of human inhalation exposure as well as the estimation of health risk attributed to this exposure pathway to dioxins and dl-PCBs. In the study air samples were taken in five urban districts of Upper Silesia, Poland, where the houses are heated with coal. The same sampling points in summer and winter were analyzed for dioxins/furans and dl-PCBs. In addition, information was collected on awareness of the residents about the co-incineration of plastic waste and effects of this activity on human health. The results show that the average daily exposure of residents of Upper Silesia to TCDD and DLCs in the heating season was about 6.5.-fold higher than in summer. The risk assessment showed that expected excess of cancer cases per 1,000,000 people ranged from 4.5 to 13.2 in winter and from 0.9 to 2.1 in summer. The practice of mixing waste with coal for houses heating has been confirmed by investigated families, who do not associate it with the possibility of negative health effects. Air pollution can be a significant source of dioxin and dl-PCB for people during the winter season, as a result of co-burning coal and waste containing plastics. The dose of dioxins inhaled through the respiratory pathway in winter can be associated with the higher cancer risk in the population of Upper Silesia. Copyright© by the National Institute of Public Health, Prague 2015.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and biphenyls (PCBs) in home-produced eggs

NARCIS (Netherlands)

Hoogenboom, L.A.P.; Dam, ten G.; Bruggen, van Mark; Jeurissen, Suzanne; Leeuwen, van S.P.J.; Theelen, R.M.C.; Zeilmaker, M.J.

2016-01-01

Home produced eggs from 62 addresses in the Netherlands were investigated for the levels of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and biphenyls (PCBs), both dioxin-like (dl) and non-dioxin-like (ndl). Compared to commercial eggs, levels were relatively high with a median of 4.6

TCDD alters medial epithelial cell differentiation during palatogenesis

International Nuclear Information System (INIS)

Abbott, B.D.; Birnbaum, L.S.

1989-01-01

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a widely distributed, persistent environmental contaminant that is teratogenic in mice, where it induces hydronephrosis and cleft palate. The incidence of clefting has been shown to be dose dependent after exposure on either gestation Day (GD) 10 or 12, although the embryo is more susceptible on GD 12. TCDD-exposed palatal shelves meet but do not fuse, and programmed cell death of the medial epithelial cells is inhibited. The mechanism of action through which TCDD alters the program of medial cell development has not been examined in earlier studies, and it is not known whether the mechanism is the same regardless of the dose or developmental stage of exposure. In this study, C57BL/6N mice, a strain sensitive to TCDD, were dosed orally on GD 10 or 12 with 0, 6, 12, 24, or 30 micrograms/kg body wt, in 10 ml corn oil/kg. Embryonic palatal shelves were examined on GD 14, 15, or 16. The degree of palatal closure, epithelial surface morphology, and cellular ultrastructure, the incorporation of [3H]TdR, the expression of EGF receptors, and the binding of 125I-EGF were assessed. After exposure on GD 10 or 12, TCDD altered the differentiation pathway of the medial epithelial cells. The palatal shelves were of normal size and overall morphology, but fusion of the medial epithelia of the opposing shelves did not occur. TCDD prevented programmed cell death of the medial peridermal cells. The expression of EGF receptors by medial cells continued through Day 16 and the receptors were able to bind ligand. The medial cells differentiated into a stratified, squamous, keratinizing epithelium. The shift in phenotype to an oral-like epithelium occurred after exposure on either GD 10 or 12. At the lower dose (6 micrograms/kg), fewer cleft palates were produced, but those shelves which did respond had a fully expressed shift in differentiation

Associations between congenital cryptorchidism in newborn boys and levels of dioxins and PCBs in placenta

DEFF Research Database (Denmark)

Virtanen, H E; Koskenniemi, J J; Sundqvist, E

2012-01-01

In animal studies, exposure to dioxins has been associated with disrupted development of the male reproductive system, including testicular maldescent. Some polychlorinated biphenyls (PCBs) have also dioxin-like effects. In addition, one previous case-control study has reported an association...... between congenital cryptorchidism and colostrum PCB levels. We performed a case-control study to evaluate whether congenital cryptorchidism in boys was associated with increased levels of dioxins or PCBs in placenta reflecting foetal exposure. In addition, associations between placenta levels...... controls) and 168 Danish (39 cases, 129 controls)] were analysed for 17 toxic polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and 37 PCBs (including 12 dioxin-like PCBs). Infant serum samples taken at 3 months were analysed for reproductive hormones. No significant differences between cases...

Risks to health from radiation at low dose rates

International Nuclear Information System (INIS)

Gentner, N.E.; Osborne, R.V.

1997-01-01

Our focus is on whether, using a balance-of-evidence approach, it is possible to say that at a low enough dose, or at a sufficiently low dose rate, radiation risk reduces to zero in a population. We conclude that insufficient evidence exists at present to support such a conclusion. In part this reflects statistical limitations at low doses, and in part (although mechanisms unquestionably exist to protect us against much of the damage induced by ionizing radiation) the biological heterogeneity of human populations, which means these mechanisms do not act in all members of the population at all times. If it is going to be possible to demonstrate that low doses are less dangerous than we presently assume, the evidence, paradoxically, will likely come from studies of higher dose and dose rate scenarios than are encountered occupationally. (author)

Super-low dose endotoxin pre-conditioning exacerbates sepsis mortality.

Science.gov (United States)

Chen, Keqiang; Geng, Shuo; Yuan, Ruoxi; Diao, Na; Upchurch, Zachary; Li, Liwu

2015-04-01

Sepsis mortality varies dramatically in individuals of variable immune conditions, with poorly defined mechanisms. This phenomenon complements the hypothesis that innate immunity may adopt rudimentary memory, as demonstrated in vitro with endotoxin priming and tolerance in cultured monocytes. However, previous in vivo studies only examined the protective effect of endotoxin tolerance in the context of sepsis. In sharp contrast, we report herein that pre-conditionings with super-low or low dose endotoxin lipopolysaccharide (LPS) cause strikingly opposite survival outcomes. Mice pre-conditioned with super-low dose LPS experienced severe tissue damage, inflammation, increased bacterial load in circulation, and elevated mortality when they were subjected to cecal-ligation and puncture (CLP). This is in opposite to the well-reported protective phenomenon with CLP mice pre-conditioned with low dose LPS. Mechanistically, we demonstrated that super-low and low dose LPS differentially modulate the formation of neutrophil extracellular trap (NET) in neutrophils. Instead of increased ERK activation and NET formation in neutrophils pre-conditioned with low dose LPS, we observed significantly reduced ERK activation and compromised NET generation in neutrophils pre-conditioned with super-low dose LPS. Collectively, our findings reveal a novel mechanism potentially responsible for the dynamic programming of innate immunity in vivo as it relates to sepsis risks.

Super-low Dose Endotoxin Pre-conditioning Exacerbates Sepsis Mortality

Directory of Open Access Journals (Sweden)

Keqiang Chen

2015-04-01

Full Text Available Sepsis mortality varies dramatically in individuals of variable immune conditions, with poorly defined mechanisms. This phenomenon complements the hypothesis that innate immunity may adopt rudimentary memory, as demonstrated in vitro with endotoxin priming and tolerance in cultured monocytes. However, previous in vivo studies only examined the protective effect of endotoxin tolerance in the context of sepsis. In sharp contrast, we report herein that pre-conditioning with super-low or low dose endotoxin lipopolysaccharide (LPS cause strikingly opposite survival outcomes. Mice pre-conditioned with super-low dose LPS experienced severe tissue damage, inflammation, increased bacterial load in circulation, and elevated mortality when they were subjected to cecal-ligation and puncture (CLP. This is in contrast to the well-reported protective phenomenon with CLP mice pre-conditioned with low dose LPS. Mechanistically, we demonstrated that super-low and low dose LPS differentially modulate the formation of neutrophil extracellular trap (NET in neutrophils. Instead of increased ERK activation and NET formation in neutrophils pre-conditioned with low dose LPS, we observed significantly reduced ERK activation and compromised NET generation in neutrophils pre-conditioned with super-low dose LPS. Collectively, our findings reveal a mechanism potentially responsible for the dynamic programming of innate immunity in vivo as it relates to sepsis risks.

Liver Tumor Promotion by 2,3,7,8-Tetrachlorodibenzo-p-dioxin Is Dependent on the Aryl Hydrocarbon Receptor and TNF/IL-1 Receptors

Science.gov (United States)

Kennedy, Gregory D.; Nukaya, Manabu; Moran, Susan M.; Glover, Edward; Weinberg, Samuel; Balbo, Silvia; Hecht, Stephen S.; Pitot, Henry C.; Drinkwater, Norman R.; Bradfield, Christopher A.

2014-01-01

We set out to better understand the signal transduction pathways that mediate liver tumor promotion by 2,3,7,8-tetrachlorodibenzo-p-dioxn (“dioxin”). To this end, we first employed congenic mice homozygous for either the Ahrb1 or Ahrd alleles (encoding an aryl hydrocarbon receptor (AHR) with high or low binding affinity for dioxin, respectively) and demonstrated that hepatocellular tumor promotion in response to dioxin segregated with the Ahr locus. Once we had genetic evidence for the importance of AHR signaling, we then asked if tumor promotion by dioxin was influenced by “interleukin-1 (IL-1)-like” inflammatory cytokines. The importance of this question arose from our earlier observation that aspects of the acute hepatocellular toxicity of dioxin are dependent upon IL1-like cytokine signaling. To address this issue, we employed a triple knock-out (TKO) mouse model with null alleles at the loci encoding the three relevant receptors for tumor necrosis factors α and β and IL-1α and IL-1β (i.e., null alleles at the Tnfrsf1a, Tnfrsf1b, and Il-1r1 loci). The observation that TKO mice were resistant to the tumor promoting effects of dioxin in liver suggests that inflammatory cytokines play an important step in dioxin mediated liver tumor promotion in the mouse. Collectively, these data support the idea that the mechanism of dioxin acute hepatotoxicity and its activity as a promoter in a mouse two stage liver cancer model may be similar, i.e., tumor promotion by dioxin, like acute hepatotoxicity, are mediated by the linked action of two receptor systems, the AHR and the receptors for the “IL-1-like” cytokines. PMID:24718703

Validation of rapid dioxin screening by GC-FID in fish products

Energy Technology Data Exchange (ETDEWEB)

Bassompierre, M.; Munck, L.; Bro, R.; Tomasi, G.; Engelsen, S.B. [Royal Veterinary and Agricultural Univ., Copenhagen (Denmark). Food Technology, Institute of Food Science, Centre for Advanced Food Studies

2004-09-15

A novel, cost- and time-effective dioxin screening method was developed and validated for fish product. The method is based on multivariate covariance between fatty acid composition monitored by GC-FID and dioxin content as teq WHO pg/ g fat. A dioxin range varying from 1.1 to 47.1 pg TEQ-WHO/ g fat using 65 fish meal samples was accessible for model calibration. An optimal multivariate dioxin prediction model was developed based on automatic peak integration, thereby enabling extraction of the area of 140 peaks from the gas chromatogramms. Models were produced employing partial least squares regression (PLS) based upon the duplicate GC-FID run and 46 specific peaks, selected after variable selection from the 140 investigated. The best results were yielded by local pls modelling employing three latent variables based upon the 12 nearest neighbors. For each prediction sample, the neighbors, yielding the 12 smallest sum of squares of differences to the test sample using the 140 peaks, were extracted from the whole calibration set and a local model built using these 12 chromatograms and related dioxin content. Prediction performance was thereafter validated for 10 fully independent samples. The performance of this model, yielded a correlation of 0.85 (r{sup 2}) and a root mean square error of prediction of 2.3 pg PCDD/F TEQWHO/ g fat.

Ageing effects of polymers at very low dose-rates

International Nuclear Information System (INIS)

Chenion, J.; Armand, X.; Berthet, J.; Carlin, F.; Gaussens, G.; Le Meur, M.

1987-10-01

The equipment irradiation dose-rate into the containment is variable from 10 -6 to 10 -4 gray per second for the most exposed materials. During qualification, safety equipments are submitted in France to dose-rates around 0.28 gray per second. This study purpose is to now if a so large irradiation dose-rate increase is reasonable. Three elastomeric materials used in electrical cables, o'rings seals and connectors, are exposed to a very large dose-rates scale between 2.1.10 -4 and 1.4 gray per second, to 49 KGy dose. This work was carried out during 3.5 years. Oxygen consumption measurement of the air in contact with polymer materials, as mechanical properties measurement show that: - at very low dose-rate, oxygen consumption is maximum at the same time (1.4 year) for the three elastomeric samples. Also, mechanical properties simultaneously change with oxygen consumption. At very low dose-rate, for the low irradiation doses, oxygen consumption is at least 10 times more important that it is showed when irradiation is carried out with usual material qualification dose-rate. At very low dose-rate, oxygen consumption decreases when absorbed irradiation dose by samples increases. The polymer samples irradiation dose is not still sufficient (49 KGy) to certainly determine, for the three chosen polymer materials, the reasonable irradiation acceleration boundary during nuclear qualification tests [fr

Addition of low-dose ketamine to midazolam and low-dose bupivacaine improves hemodynamics and postoperative analgesia during spinal anesthesia for cesarean section

Directory of Open Access Journals (Sweden)

Ahmed Sobhy Basuni

2016-01-01

Conclusion: Intrathecal low-dose ketamine combined with midazolam and low-dose bupivacaine stabilizes hemodynamics and prolongs postoperative analgesia without significant side-effects in parturients undergoing CS.

An experimental study on the alteration of thermal enhancement ratio by combination of split dose hyperthermia irradiation

Energy Technology Data Exchange (ETDEWEB)

Park, Sun Ok; Kim, Hee Seup [Ewha Womens University College of Medicine, Seoul (Korea, Republic of)

1983-06-15

The study was undertaken to evaluate the alteration of thermal enhancement ratio as a function of time intervals between two split dose hyperthermias followed by irradiation. For the experiments, 330 mice were divided into 3 groups; the first, 72 mice were used to evaluate the heat reaction by single dose hyperthermia and heat resistance by split dose hyperthermia, the second, 36 mice were used to evaluate the radiation reaction by irradiation only, and the third, 222 mice were used for TER observation by combination of single dose hyperthermia and irradiation, and TER alteration by combination of split dose hyperthermia and irradiation. For each group the skin reaction score of mouse tail was used for observation and evaluation of the result of heat and irradiation. The results obtained are summarized as follows: 1. The heating time resulting 50% necrosis (ND{sub 5}0) Was 101 minutes in 43 .deg. C and 24 minutes in 45 .deg. C hyperthermia, which indicated that three is reciprocal proportion between temperature and heating time. 2. Development of heat resistance was observed by split dose hyperthermia. 3. The degree of skin reaction by irradiation only was increased proportionally as a function of radiation dose, and calculated radiation dose corresponding to skin score 1.5 (D{sub 1}.5) was 4,137 rads. 4. Obtained thermal enhancement ratio by combination of single dose hyperthermia and irradiation was increased proportionally as a function of heating time. 5. Thermal enhancement ratio was decreased by combination of split dose hyperthermia and irradiation, which was less intense and lasted longer than development of heat resistance. In summary, these studies indicate that the alteration of thermal enhancement ratio has influence on heat resistance by split dose hyperthermia and irradiation.

Additional exposure of the Irish adult population to dioxins and PCBs from the diet as a consequence of the 2008 Irish dioxin food contamination incident.

Science.gov (United States)

Tlustos, C; Anderson, W; Flynn, A; Pratt, I

2014-01-01

In 2008, the discovery of elevated levels of dioxins and PCBs in a porcine fat sample taken as part of the national residues monitoring programme led to the detection of a major feed contamination incidence in the Republic of Ireland. To estimate additional exposure to dioxins and PCBs due to the contamination incident, all data associated with the contamination incident were collected and reviewed. An exposure model was devised that took into account the proportion of contaminated product reaching the final consumer during the contamination incident window and which utilised all additional information that became available after the incident occurred. Exposure estimates derived for both dioxins and PCBs showed that the body burden of the general population remained largely unaffected by the contamination incident and only approximately 10% were exposed to elevated levels of dioxins and PCBs. Whilst this proportion of the population experienced quite a significant additional load to the existing body burden, the estimated exposure values do not suggest that these would be associated with adverse health effects, based on current knowledge. The exposure period was also limited in time to approximately 3 months, following the recall of contaminated meat immediately on detection of the contamination.

Xenoestrogenic and dioxin-like activity in blood of East Greenland polar bears (Ursus maritimus)

DEFF Research Database (Denmark)

Erdmann, Simon Erik; Dietz, Rune; Sonne, Christian

2013-01-01

chromatography (HPLC). ER mediated transactivity was determined using the ER luciferase reporter MVLN cell assay. The extracts were tested alone (XER) and together with 17β-estradiol (E2) as a physiological mimic (XERcomp). Dioxins and dioxin-like (DL) compounds were extracted by a combination of SPE...... and the Supelco Dioxin Prep System®. AhR mediated dioxin-like transactivity was determined using the AhR luciferase reporter Hepa 1.12cR cell assay. Agonistic ER transactivity was elicited by 19% of the samples, and a further increased E2 induced ER response was found for 52%, whereas 17% antagonized the E2...

Diverse effects of a low dose supplement of lipidated curcumin in healthy middle aged people

Directory of Open Access Journals (Sweden)

DiSilvestro Robert A

2012-09-01

Full Text Available Abstract Background Curcumin extracts of turmeric are proposed to produce health benefits. To date, human intervention studies have focused mainly on people with existing health problems given high doses of poorly absorbed curcumin. The purpose of the current study was to check whether in healthy people, a low dose of a lipidated curcumin extract could alter wellness-related measures. Methods The present study was conducted in healthy middle aged people (40–60 years old with a low dose of curcumin (80 mg/day in a lipidated form expected to have good absorption. Subjects were given either curcumin (N = 19 or placebo (N = 19 for 4 wk. Blood and saliva samples were taken before and after the 4 weeks and analyzed for a variety of blood and saliva measures relevant to health promotion. Results Curcumin, but not placebo, produced the following statistically significant changes: lowering of plasma triglyceride values, lowering of salivary amylase levels, raising of salivary radical scavenging capacities, raising of plasma catalase activities, lowering of plasma beta amyloid protein concentrations, lowering of plasma sICAM readings, increased plasma myeloperoxidase without increased c-reactive protein levels, increased plasma nitric oxide, and decreased plasma alanine amino transferase activities. Conclusion Collectively, these results demonstrate that a low dose of a curcumin-lipid preparation can produce a variety of potentially health promoting effects in healthy middle aged people.

Cancer and low dose responses in vivo: implications for radiation protection

International Nuclear Information System (INIS)

Mitchel, R.E.J.

2006-01-01

Full text: Radiation protection practices assume that cancer risk is linearly proportional to total dose, without a threshold, both for people with normal cancer risk and for people who may be genetically cancer prone. Mice heterozygous for the Tp 53 gene are cancer prone, and their increased risk from high doses was not different from Tp 53 normal mice. However, in either Tp 53 normal or heterozygous mice, a single low dose of low LET radiation given at low dose rate protected against both spontaneous and radiation-induced cancer by increasing tumor latency. Increased tumor latency without a cancer frequency change implies that low doses in vivo primarily slow the process of genomic instability, consistent with the elevated capacity for correct DSB rejoining seen in low dose exposed cells. The in vivo animal data indicates that, for low doses and low dose rates in both normal and cancer prone adult mice, risk does not increase linearly with dose, and dose thresholds for increased risk exist. Below those dose thresholds (which are influenced by Tp 53 function) overall risk is reduced below that of unexposed control mice, indicating that Dose Rate Effectiveness Factors (DREF) may approach infinity, rather than the current assumption of 2. However, as dose decreases, different tissues appear to have different thresholds at which detriment turns to protection, indicating that individual tissue weighting factors (Wt) are also not constant, but vary from positive values to zero with decreasing dose. Measurements of Relative Biological Effect between high and low LET radiations are used to establish radiation weighting factors (Wr) used in radiation protection, and these are also assumed to be constant with dose. However, since the risk from an exposure to low LET radiation is not constant with dose, it would seem unlikely that radiation-weighting factors for high LET radiation are actually constant at low dose and dose rate

Limited mobility of dioxins near San Jacinto super fund site (waste pit) in the Houston Ship Channel, Texas due to strong sediment sorption.

Science.gov (United States)

Louchouarn, Patrick; Seward, Shaya M; Cornelissen, Gerard; Arp, Hans Peter H; Yeager, Kevin M; Brinkmeyer, Robin; Santschi, Peter H

2018-02-20

Sediments from a waste pit in Houston Ship Channel (HSC) were characterized using a number of molecular markers of natural organic matter fractions (e.g., pyrogenic carbon residues, PAHs, lignins), in addition to dioxins, in order to test the hypothesis that the dispersal and mobility of dioxins from the waste pit in the San Jacinto River is minimal. Station SG-6, sampled at the site of the submerged waste pit, had the highest dioxin/furan concentrations reported for the Houston Ship Channel/Galveston Bay (HSC/GB) system (10,000-46,000 pg/g), which translated into some of the highest reported World Health Organization Toxic Equivalents (TEQs: 2000-11,000 pg/g) in HSC sediments. Using a multi-tracer approach, this study confirmed our hypothesis that sludges from chlorinated pulps are a very likely source of dioxins/furans to this pit. However, this material also contained large quantities of additional hydrophobic organic contaminants (PAHs) and pyrogenic markers (soot-BC, levoglucosan), pointing to the co-occurrence of petroleum hydrocarbons and combustion byproducts. Comparison of dioxin/furan signatures in the waste pit with those from sediments of the HSC and a control site suggests that the remobilization of contaminated particles did not occur beyond the close vicinity of the pit itself. The dioxins/furans in sediments outside the waste pit within the HSC are rather from other diffuse inputs, entering the sedimentary environment through the air and water, and which are comprised of a mixture of industrial and municipal sources. Fingerprinting of waste pit dioxins indicates that their composition is typical of pulp and paper sources. Measured pore water concentrations were 1 order of magnitude lower than estimated values, calculated from a multiphase sorption model, indicating low mobility of dioxins within the waste pit. This is likely accomplished by co-occurring and strong sorbing pyrogenic and petrogenic residues in the waste pit, which tend to keep

Conditioned instrumental behaviour in the rat: Effects of prenatal irradiation with various low dose-rate doses

International Nuclear Information System (INIS)

Klug, H.

1986-01-01

4 groups of rats of the Wistar-strain were subjected to γ-irradiation on the 16th day of gestation. 5 rats received 0,6 Gy low dose rate irradiation, 5 animals received 0,9 Gy low dose and 6 high dose irradiation, 3 females were shamirradiated. The male offspring of these 3 irradiation groups and 1 control group were tested for locomotor coordination on parallel bars and in a water maze. The female offspring were used in an operant conditioning test. The locomotor test showed slight impairment of locomotor coordination in those animals irradiated with 0,9 Gy high dose rate. Swimming ability was significantly impaired by irradiation with 0,9 Gy high dose rate. Performance in the operant conditioning task was improved by irradiation with 0,9 Gy both low and high dose rate. The 0,9 Gy high dose rate group learned faster than all the other groups. For the dose of 0,9 Gy a significant dose rate effect could be observed. For the dose of 0,6 Gy a similar tendency was observed, differences between 0,6 Gy high and low dose rate and controls not being significant. (orig./MG) [de

Dioxins and PCBs in game animals: Interspecies comparison and related consumer exposure.