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Sample records for chronic uranium exposure

  1. Comparative sensitivity of three populations of the cladoceran Moinodaphnia macleayi to acute and chronic uranium exposure.

    Science.gov (United States)

    Semaan, M; Holdway, D A; van Dam, R A

    2001-10-01

    Assessment of differences in the response of three different populations of the tropical cladoceran Moinodaphnia macleayi to uranium exposure was evaluated. The populations tested included a laboratory stock (maintained for 10 years), a wild population collected from Bowerbird Billabong (an uncontaminated environment), and a population collected from Djalkmara Billabong (a relatively contaminated environment with elevated levels of uranium), located on the Ranger uranium mine site, Jabiru East, NT, Australia. Chronic and acute toxicity of uranium was determined for all three populations. The no-observed-effect-concentration (NOEC; reproduction) and lowest observed-effect-concentration (LOEC; reproduction) for uranium ranged between 8-31 micrograms L-1 and 20-49 micrograms L-1, respectively, for all three populations. The 48 h EC50 (immobilization-lethality) for uranium ranged between 160-390 micrograms L-1 for all three populations. There was little difference in the response of the three populations of M. macleayi to acute and chronic uranium exposure, although the response of the laboratory population to chronic uranium exposure appeared more variable than the "wild" populations. There was no apparent tolerance in the population of M. macleayi obtained from Djalkmara Billabong when exposed to elevated levels of uranium. M. macleayi was significantly more sensitive to uranium exposure than other species previously tested. It was concluded that the sensitivity of the laboratory population (to uranium) is still representative of natural M. macleayi populations. PMID:11594022

  2. Nuclear toxicology file: ecological consequences of a chronic exposure to uranium

    International Nuclear Information System (INIS)

    This article presents the thought process and the current developments, based on the experimental acquisition of the answers of the alive organisms to the chronic low dose exposures of natural uranium in fresh water, to identify the consequences of this exposure on the populations composing the ecosystems. The results acquired on the zebra fish (Danio rerio) show an impact on the first steps of development. We note a delay of hatching upon 40 % from 20 μg/l of uranium. This delay comes along with a decrease of the size and with a reduction of the growth of larvas as well as with an increase of their mortality for higher uranium concentration. For adults exposed to uranium a decrease of reproduction success is observed from a concentration of 20μg/l. The consequences in term of fertility (total number of laid roes) are drastic, with a reduction of a factor 2 and 60, for the organisms exposed respectively to 20 and 250 μg/l of uranium. A study was also made on several generations (populations of benthic invertebrates), it suggests an adaptation (genetic selection) but created a bigger fragility to a new environment even identical to their environment of origin with notably a decrease of the reproduction. (N.C.)

  3. Heavy metal uranium affects the brain cholinergic system in rat following sub-chronic and chronic exposure

    International Nuclear Information System (INIS)

    Uranium is a heavy metal naturally present in the environment that may be chronically ingested by the population. Previous studies have shown that uranium is present in the brain and alters behaviour, notably locomotor activity, sensorimotor ability, sleep/wake cycle and the memory process, but also metabolism of neurotransmitters. The cholinergic system mediates many cognitive systems, including those disturbed after chronic exposure to uranium i.e., spatial memory, sleep/wake cycle and locomotor activity. The objective of this study was to assess whether these disorders follow uranium-induced alteration of the cholinergic system. In comparison with 40 control rats, 40 rats drank 40 mg/L uranyl nitrate for 1.5 or 9 months. Cortex and hippocampus were removed and gene expression and protein level were analysed to determine potential changes in cholinergic receptors and acetylcholine levels. The expression of genes showed various alterations in the two brain areas after short- and long-term exposure. Nevertheless, protein levels of the choline acetyltransferase enzyme (ChAT), the vesicular transporter of acetylcholine (VAChT) and the nicotinic receptor β2 sub-unit (nAChRβ2) were unmodified in all cases of the experiment and muscarinic receptor type 1 (m1AChR) protein level was disturbed only after 9 months of exposure in the cortex (-30%). Acetylcholine levels were unchanged in the hippocampus after 1.5 and 9 months, but were decreased in the cortex after 1.5 months only (-22%). Acetylcholinesterase (AChE) activity was also unchanged in the hippocampus but decreased in the cortex after 1.5 and 9 months (-16% and -18%, respectively). Taken together, these data indicate that the cholinergic system is a target of uranium exposure in a structure-dependent and time-dependent manner. These cholinergic alterations could participate in behavioural impairments.

  4. Role of oxidative stress in liver and kidney in uranium toxicity after chronic exposure

    International Nuclear Information System (INIS)

    Uranium is a radioactive heavy metal found in the environment. Due to its natural presence and to civil and militaries activities, general population can be exposed to U throughout drinking water or contaminated food. The pro/anti-oxidative system is a defense system which is often implicated in case of acute exposure to U. The aim of this thesis is to study the role of the pro/anti-oxidative system after chronic exposure to U in the liver and the kidney. After chronic exposure of rats to different U concentrations, this radionuclide accumulated in the organs in proportion to U intake; until 6 μg.g-1 of kidney tissues. U is localized in nucleus of the proximal tubular cells of the kidney. No nephrotoxicity was described even for the higher U level in drinking water and a reinforcement of the pro/anti-oxidative system with an increase in glutathione is observed. The study of U internal contamination in Nrf2 deficient mice, a cytoprotective transcription factor involved in the anti-oxidative defense has been realized. U accumulate more in Nrf2 mice than in WT mice but the biologic effects of U on the pro/anti-oxidative system did not seem to implicate Nrf2. At the cell level, a correlation between U distribution in HepG2 cells and the biological effects on this system is observed after U exposure at low concentrations. Soluble distribution of U is observed in cell nucleus. The apparition of U precipitates is correlated to the establishment of the adaptive mechanisms overtime which are overwhelmed and lead to a cellular toxicity at higher U level. In conclusion, these results suggest that the reinforcement of pro/anti-oxidative system could be an adaptive mechanism after chronic exposure at low U concentration. (author)

  5. Effects of depleted uranium chronic exposure on detoxification systems in vivo and in vitro

    International Nuclear Information System (INIS)

    Uranium (U) is a heavy metal naturally presents in the environment. The aim of this work is to study effects of a U exposure on organs involved in the detoxification: the kidney and the liver (and notably the xenobiotics metabolizing enzymes (XME)). In order to mimic population chronic exposure, rats were contaminated during 9 months through the drinking water (40 mg/L). In vivo results show that U, in our experimental conditions, does not induce neither nephrotoxicity nor sensitivity to increase a renal toxicity induced by gentamicin. In the liver, U provokes impairments on the XME gene expression, particularly CYP3A. Nevertheless, paracetamole metabolism is modified only if it is administrated at a hepatotoxic dose. The in vitro results suggest an indirect effect of uranium on the XME, probably dependant of body adaptation mechanisms. Besides, in vitro studies were underline cytotoxic properties of U as well as the localisation of its soluble and/or participated forms in cytoplasmic and nuclear compartment. (author)

  6. The reproductive effects in rats after chronic oral exposure to low-dose depleted uranium

    International Nuclear Information System (INIS)

    This two-generation study evaluated the effects of depleted uranium (DU) on reproduction in rats. Across two generations, Wistar rats (30/sex/group) were maintained on feed containing DU at dose levels of 0 (control group), 4 (DU4 group), or 40 (DU40 group) mg kg-1 day-1 for 4 months prior to mating. After 4 months of exposure, the pregnancy rate, normal labour rate, and survival rate of offspring produced by F1 rats were all significantly decreased as compared to the control group, and especially in the DU40 group, these parameters fell by half to two-thirds, while no adverse effects were evident in F0 rats. The uranium content in the testes and ovaries of F1 rats in the DU4 and DU40 groups was significantly higher than that found in F0 rats. The levels of sex hormone in the serum were disorder in both generations. The enzymes related to spermiogenesis were also significantly different between generations, and the damage was more severe in F1 rats. In conclusion, the reproductive effects in F0 rats were slight after chronic oral exposure to DU, while the effects were obvious in F1 rats. (author)

  7. Effects of chronic uranium internal exposure on mortality: Results of a pilot study among French nuclear workers

    International Nuclear Information System (INIS)

    Background: This article presents the mortality data compiled among a cohort of workers at risk of internal uranium exposure and discusses the extent to which this exposure might differentiate them from other nuclear workers. Methods: The cohort consisted of 2897 Areva-NC-Pierrelatte plant workers, followed from 1 January 1968 through 31 December 2006 (79,892 person-years). Mortality was compared with that of the French population, by calculating Standardized Mortality Ratios (SMR) and 95 % confidence intervals (CI95 %). External radiation exposure was reconstructed using external dosimetry archives. Internal uranium exposure was assessed using a plant-specific job-exposure-matrix, considering six types of uranium compounds according to their nature (natural and reprocessed uranium [RPU] and solubility [fast-F, moderate-M, and slow-S]). Exposure-effect analyses were performed for causes of death known to be related to external radiation exposure (all cancers and circulatory system diseases) and cancer of uranium target-organs (lung and hematopoietic and lymphatic tissues, HLT). Results: A significant deficit of mortality from all causes (SMR = 0.58; CI95% [0.53-0.63]), all cancers (SMR = 0.72; CI95% [0.63-0.82]) and smoking related cancers was observed. Non-significant 30 %-higher increase of mortality was observed for cancer of pleura (SMR = 2.32; CI95% [0.75-5.41]), rectum and HLT, notably non-Hodgkin's lymphoma (SMR = 1.38; CI95% [0.63-2.61]) and chronic lymphoid leukemia (SMR = 2.36; CI95% [0.64-6.03]). No exposure-effect relationship was found with external radiation cumulative dose. A significant exposure-effect relationship was observed for slowly soluble uranium, particularly RPU, which was associated with an increase in mortality risk reaching 8 to 16 % per unit of cumulative exposure score and 10 to 15 % per year of exposure duration. Conclusion: The Areva-NC-Pierrelatte workers cohort presents a non-significant over-mortality from HLT cancers, notably of

  8. Immunological changes of chronic oral exposure to depleted uranium in mice.

    Science.gov (United States)

    Hao, Yuhui; Ren, Jiong; Liu, Jing; Yang, Zhangyou; Liu, Cong; Li, Rong; Su, Yongping

    2013-07-01

    Direct ingestion of contaminated soil by depleted uranium (DU) might lead to internal exposure to DU by local populations through hand contamination. The purpose of this study was to assess the immunological changes of long-term exposure to various doses of DU in mice. Three-week-old Kunming mice were divided into the following 4 groups based on the various feeding doses (containing DU): 0 (control group), 3 (DU3 group), 30 (DU30 group), and 300 mg/kg feed (DU300 group). After 4 months of exposure, in the DU300 group, the innate immune function decreased, manifesting as decreased secretion of nitric oxide, interleukin (IL)-1β, IL-18, and tumour necrosis factor (TNF)-α in the peritoneal macrophages, as well as reduced cytotoxicity of the splenic natural killer cells. Moreover, the cellular and humoral immune functions were abnormal, as manifested by decreased proliferation of the splenic T cells, proportion of the cluster of differentiation (CD) 3(+) cells, ratio of CD4(+)/CD8(+) cells and delayed-type hypersensitivity, and increased proliferation of the splenic B cells, total serum immunoglobin (Ig) G and IgE, and proportion of splenic mIgM(+)mIgD(+) cells. Through stimulation, the secretion levels of interferon (IFN)-γ and TNF-α in the splenic cells were reduced, and the levels of IL-4 and IL-10 were increased. By comparison, in the DU30 and DU3 groups, the effects were either minor or indiscernible. In conclusions, chronic intake of higher doses of DU (300 mg/kg) had a significant impact on the immune function, most likely due to an imbalance in T helper (Th) 1 and Th2 cytokines. PMID:23659960

  9. Uranium microdistribution in renal cortex of rats after chronic exposure: a study by secondary ion mass spectrometry microscopy.

    Science.gov (United States)

    Tessier, Christine; Suhard, David; Rebière, François; Souidi, Maâmar; Dublineau, Isabelle; Agarande, Michelle

    2012-02-01

    For a few years, the biological effects on ecosystems and the public of the bioaccumulation of radionuclides in situations of chronic exposures have been studied. This work, in keeping with the ENVIRHOM French research program, presents the uranium microdistribution by secondary ion mass spectrometry (SIMS) technique in the renal cortex of rats following chronic exposure to this low level element in the drinking water (40 mg/L) as a function to exposure duration (6, 9, 12, and 18 months). The SIMS mass spectra and 238U+ ion images produced with a SIMS CAMECA 4F-E7 show the kinetic of uranium accumulation in the different structures of the kidney. For the rats contaminated up to 12 months, the radioelement is mainly fixed in the proximal tubules; then after 18 exposure months, uranium is detected in all the segments of the nephron. This work has also shown that ion microscopy is an analytical method to detect trace elements and give elemental cartography at the micrometer scale. PMID:22217926

  10. Reproductive toxicity in rats after chronic oral exposure to low dose of depleted uranium

    International Nuclear Information System (INIS)

    Objective: To study the reproductive toxicity in rats induced by low dose of depleted uranium (DU). Methods: Male and female rats(F0 generation) were exposed to DU in food at doses of 0, 0.4, 4 and 40 mg·kg-1·d-1 for 160 days, respectively. Then the activities of enzymes in testis and sexual hormone contents in serum were detected. Mature male rats were mated with female rats exposed to the same doses for 14 days. Pregnant rate and normal labor rate in F0 rats were detected, as well as the survival rate and weight of F1 rats within 21 d after birth. Results: No adverse effects of DU on fertility were evident at any dose in F0 rats. Compared with control group, the rate of pregnancy, normal labor, survival of offspring birth and offspring nurture in F1 generation of high-dose group reduced to 40.0%, 33.3%, 33.3%, and 33.3%, respectively. The sexual hormone contents in F0 generation exposed increased, but those in Fl rats decreased significantly. The activities of lactate dehydrogenase-X (LDH-X) decreased in F1 rats exposed to high-dose of DU, and those of sorbitol dehydrogenase (SDH), LDH and Na+-K+-ATPase decreased in F1 rats exposed to DU. Conclusions: Reproduction function, growth and development of F0 rats are not obviously affected after chronic oral exposure to DU, while the toxicity effects in F1 generation was observed at any dose. (authors)

  11. Nuclear toxicology file: ecological consequences of a chronic exposure to uranium; Dossier toxicologie nucleaire: Consequences ecologiques d'une exposition chronique a l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Adam, Ch.; Alonzo, F.; Bonzom, J.M.; Gilbin, R.; Garnier-Laplace, J.; Simon, O. [Institut de Radioprotection et de Surete Nucleaire (IRSN:DEI/SECRE), Service d' Etude du Comportement des Radionucleides dans les Ecosystemes, 13 - Saint-Paul-lez-Durance (France)

    2008-09-15

    This article presents the thought process and the current developments, based on the experimental acquisition of the answers of the alive organisms to the chronic low dose exposures of natural uranium in fresh water, to identify the consequences of this exposure on the populations composing the ecosystems. The results acquired on the zebra fish (Danio rerio) show an impact on the first steps of development. We note a delay of hatching upon 40 % from 20 {mu}g/l of uranium. This delay comes along with a decrease of the size and with a reduction of the growth of larvas as well as with an increase of their mortality for higher uranium concentration. For adults exposed to uranium a decrease of reproduction success is observed from a concentration of 20{mu}g/l. The consequences in term of fertility (total number of laid roes) are drastic, with a reduction of a factor 2 and 60, for the organisms exposed respectively to 20 and 250 {mu}g/l of uranium. A study was also made on several generations (populations of benthic invertebrates), it suggests an adaptation (genetic selection) but created a bigger fragility to a new environment even identical to their environment of origin with notably a decrease of the reproduction. (N.C.)

  12. A study assessing the genotoxicity in rats after chronic oral exposure to a low dose of depleted uranium

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate the potential genotoxicity induced by chronic oral exposure to depleted uranium (DU). Weanling Wistar rats (F0), 50/sex/group, were exposed to DU in food at doses of 0, 4, or 40 mg kg-1 day-1 for four months. They were subsequently mated, resulting in the birth of F1 rats. Fifty F1 weanlings/sex/group were exposed for four months to the same dose levels as their parents. After four months, the uranium content in the tissues, the potential damage to the genetic material, and pathomorphological changes of the testicles were observed in both F0 and F1 rats. The genotoxicity of DU was evaluated by the following methods: sperm abnormality assessment, the bone-marrow micronucleus test, and the comet assay. Uranium content in F1 rats was significantly higher than that in F0 rats in both the kidney and ovary (p1 with F0 rats, significant differences were detected for most of the indicators, with F1 rats always exhibiting more damage (p1 rats. Genotoxicity may be induced in rats after chronic oral exposure to a low dose of DU. (author)

  13. An incident study about acute and chronic human exposure to uranium by high-resolution inductively coupled plasma mass spectrometry (HR-ICPMS).

    Science.gov (United States)

    Krystek, Petra; Ritsema, Rob

    2009-01-01

    From the year 2003 to 2005 around 1700 Dutch soldiers made a part of the international stabilisation force in Iraq. An incident happened as a group of four Dutch soldiers found a 30mm bullet identified as containing depleted uranium (DU). The main pathway of the acute exposure is via inhalation of small uranium containing particles, e.g. from a bullet during its explosion. To develop a method for acute exposure investigations were carried out about finding an efficient and suitable way to sample nasal mucus as medium of inhalation. Generally, in human exposure studies with regard to natural uranium (NU) or DU, urine is the matrix for analysis. Uranium concentrations in urine are based on daily ingestion depending on the composition of drinking water and food. A second possibility is the acute exposure to uranium after an incident, either through inhalation or impact. Nevertheless, the results deliver only interpretations in respect to chronic/long-term exposure. For the acute exposure procedures like sniffling out into cleansing tissues and rinsing the nose were tested with real-life samples from four soldiers involved in an incident with possibly acute exposure to uranium. For the quantification of uranium high-resolution inductively coupled plasma mass spectrometry (HR-ICPMS) was applied. PMID:18187363

  14. Uranium bone content as an indicator of chronic environmental exposure from drinking water

    International Nuclear Information System (INIS)

    Uranium (U) is an ubiquitous radioelement found in drinking water and food. As a consequence of its prevalence, most humans ingest a few micrograms (μg) of this element daily. It is incorporated in various organs and tissues. Several studies have demonstrated that ingested U is deposited mainly in bones. Therefore, U skeletal content could be considered as a prime indicator for low-level chronic intake. In this study, 71 archived vertebrae bone samples collected in seven Canadian cities were subjected to digestion and U analysis by inductively coupled plasma mass spectrometry. These results were correlated with U concentrations in municipal drinking water supplies, with the data originating from historical studies performed by Health Canada. A strong relationship (r2 = 0.97) was observed between the averaged U total skeletal content and averaged drinking water concentration, supporting the hypothesis that bones are indeed a good indicator of U intake. Using a PowerBASIC compiler to process an ICRP systemic model for U (ICRP, 1995a), U total skeletal content was estimated using two gastrointestinal tract absorption factors (f1 = 0.009 and 0.03). Comparisons between observed and modelled skeletal contents as a function of U intake from drinking water tend to demonstrate that neither of the f1 values can adequately estimate observed values. An f1value of 0.009 provides a realistic estimate for intake resulting from food consumption only (6.72 μg) compared to experimental data (7.4 ± 0.8 μg), whereas an f1value of 0.03 tends to better estimate U skeletal content at higher levels of U (1–10 μg L−1) in drinking water

  15. Chronic uranium exposure and growth toxicity for phytoplankton. Dose-effect relationship: first comparison of chemical and radiological toxicity

    International Nuclear Information System (INIS)

    The bioavailability of uranium for freshwater organisms, as for other dissolved metals, is closely linked to chemical speciation in solution (U aqueous speciation undergoes tremendous changes in the presence of ligands commonly found in natural waters e.g. carbonate, phosphate, hydroxide and natural organic matter). For the studied chemical domain, short-term uranium uptake experiments have already shown that the free uranyl ion concentration [UO22+] is a good predictor of uranium uptake by the green algae Chlamydomonas reinhardtii, as predicted by the Free Ion Activity Model. In agreement with these results, acidic pH and low ligands concentrations in water enhance uranium bioavailability and consequently its potential chronic effects on phytoplankton. Moreover, uranium is known to be both radio-toxic and chemo-toxic. The use of different isotopes of uranium allows to expose organisms to different radiological doses for the same molar concentration: e.g. for a given element concentration (chemical dose), replacing depleted U by U-233 obviously leads to an enhanced radiological delivered dose to organisms (x104). In this work we established relationships between uranium doses (depleted uranium and 233-U ) and effect on the growth rate of the green algae Chlamydomonas reinhardtii. Uranium bioaccumulation was also monitored. Growth rate was measured both in classical batch (0-72 hrs) and continuous (turbidostat) cultures, the latter protocol allowing medium renewal to diminish exudates accumulation and speciation changes in the medium. The differences in effects will be, if possible, related to the development of defence mechanisms against the formation of reactive oxygen species (forms of glutathione) and the production of phyto-chelatins (small peptides rich in cystein that play an important role in the homeostasis and the detoxication of metals in cells). (author)

  16. Constitution of a group of Czech and French uranium miners in order to estimate lung cancer risk linked to low chronic exposure to radon decay products

    International Nuclear Information System (INIS)

    West Bohemian and French uranium miners are characterized by a long duration of exposure to radon and its decay products, in comparison to most of the other groups of miners, studied in the recent international joint analysis by the National Cancer Institute (NCI) in USA. This analysis has confirmed the linearly increasing risk of lung cancer by cumulative radon exposure, describing the different factors that may influence this dose-response relationship. One of the main factors presently discussed is the influence of the exposure-rate effect: in other words, has the same cumulated exposure spread over 10 years the same risk of lung cancer as if it is cumulated in 2 years? The implication of an inverse exposure-rate effect for low chronic exposures as well as some methodological approaches will be discussed and tested by using the data of the Czech and French cohorts. These two cohorts present annual exposures varying by a factor of 5 to 10, French exposure rates being close or even less than 0.1 Working Level during the last 20 years. The project is integrated in a larger European project on uranium miners, co-ordinated by IPSN. (author)

  17. Effects of chronic uranium exposure on life history and physiology of Daphnia magna over three successive generations

    Energy Technology Data Exchange (ETDEWEB)

    Massarin, Sandrine [Laboratoire de Modelisation Environnementale, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 159, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Alonzo, Frederic, E-mail: frederic.alonzo@irsn.fr [Laboratoire de Modelisation Environnementale, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 159, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Garcia-Sanchez, Laurent [Laboratoire de Modelisation Environnementale, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 159, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Gilbin, Rodolphe [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 186, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Garnier-Laplace, Jacqueline [Service d' Etude du Comportement des Radionucleides dans les Ecosystemes, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 159, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Poggiale, Jean-Christophe [Laboratoire de Microbiologie, Geochimie et Ecologie Marines (UMR CNRS 6117), Centre d' Oceanologie de Marseille, Universite de la Mediterranee, Campus de Luminy, Case 901, Marseille Cedex 9, 13288 (France)

    2010-09-01

    Daphnia magna was exposed to waterborne uranium (U) at concentrations ranging from 10 to 75 {mu}g L{sup -1} over three successive generations (F0, F1 and F2). Progeny was either exposed to the same concentration as mothers to test whether susceptibility to this radioelement might vary across generations or returned to a clean medium to examine their capacity to recover after parental exposure. Maximum body burdens of 17, 32 and 54 ng U daphnid{sup -1} were measured in the different exposure conditions and converted to corresponding internal alpha dose rates. Low values of 5, 12 and 20 {mu}Gy h{sup -1} suggested that radiotoxicity was negligible compared to chemotoxicity. An increasing sensitivity to toxicity was shown across exposed generations with significant effects observed on life history traits and physiology as low as 10 {mu}g L{sup -1} and a capacity to recover partially in a clean medium after parental exposure to {<=}25 {mu}g L{sup -1}. Using a {sup 14}C-labelled food technique, the study showed that uranium affected carbon assimilation in F0 at concentrations of 25 and 75 {mu}g L{sup -1} (34 and 80% reduction respectively) and as low as 10 {mu}g L{sup -1} in F1 and F2 (40 and 36% reduction respectively). Consequences were strong for both somatic growth and reproduction and increased in severity across generations. Maximum size was reduced by 12% at 75 {mu}g L{sup -1} in F0 and 23% at 25 {mu}g L{sup -1} in F2. Reduction in 21-day fecundity ranged from 27 to 48% respectively at 25 and 75 {mu}g L{sup -1} in F0 and from 43 to 71% respectively at 10 and 25 {mu}g L{sup -1} in F2. Growth retardation caused a delay in deposition of first brood of 1.3 days at 75 {mu}g L{sup -1} in F0, of 1.9 days at 25 {mu}g L{sup -1} in F1 and of 5 days at 25 {mu}g L{sup -1} in F2. Differences in respiration rates and egg dry mass between the control and exposed daphnids were mainly an indirect result of uranium effect on body size. The observed increase in toxic effects across

  18. Effects of chronic uranium exposure on life history and physiology of Daphnia magna over three successive generations

    International Nuclear Information System (INIS)

    Daphnia magna was exposed to waterborne uranium (U) at concentrations ranging from 10 to 75 μg L-1 over three successive generations (F0, F1 and F2). Progeny was either exposed to the same concentration as mothers to test whether susceptibility to this radioelement might vary across generations or returned to a clean medium to examine their capacity to recover after parental exposure. Maximum body burdens of 17, 32 and 54 ng U daphnid-1 were measured in the different exposure conditions and converted to corresponding internal alpha dose rates. Low values of 5, 12 and 20 μGy h-1 suggested that radiotoxicity was negligible compared to chemotoxicity. An increasing sensitivity to toxicity was shown across exposed generations with significant effects observed on life history traits and physiology as low as 10 μg L-1 and a capacity to recover partially in a clean medium after parental exposure to ≤25 μg L-1. Using a 14C-labelled food technique, the study showed that uranium affected carbon assimilation in F0 at concentrations of 25 and 75 μg L-1 (34 and 80% reduction respectively) and as low as 10 μg L-1 in F1 and F2 (40 and 36% reduction respectively). Consequences were strong for both somatic growth and reproduction and increased in severity across generations. Maximum size was reduced by 12% at 75 μg L-1 in F0 and 23% at 25 μg L-1 in F2. Reduction in 21-day fecundity ranged from 27 to 48% respectively at 25 and 75 μg L-1 in F0 and from 43 to 71% respectively at 10 and 25 μg L-1 in F2. Growth retardation caused a delay in deposition of first brood of 1.3 days at 75 μg L-1 in F0, of 1.9 days at 25 μg L-1 in F1 and of 5 days at 25 μg L-1 in F2. Differences in respiration rates and egg dry mass between the control and exposed daphnids were mainly an indirect result of uranium effect on body size. The observed increase in toxic effects across generations indicated the necessity of carrying out multigeneration tests to assess environmental risk of uranium in

  19. Y-12 Uranium Exposure Study

    Energy Technology Data Exchange (ETDEWEB)

    Eckerman, K.F.; Kerr, G.D.

    1999-08-05

    Following the recent restart of operations at the Y-12 Plant, the Radiological Control Organization (RCO) observed that the enriched uranium exposures appeared to involve insoluble rather than soluble uranium that presumably characterized most earlier Y-12 operations. These observations necessitated changes in the bioassay program, particularly the need for routine fecal sampling. In addition, it was not reasonable to interpret the bioassay data using metabolic parameter values established during earlier Y-12 operations. Thus, the recent urinary and fecal bioassay data were interpreted using the default guidance in Publication 54 of the International Commission on Radiological Protection (ICRP); that is, inhalation of Class Y uranium with an activity median aerodynamic diameter (AMAD) of 1 {micro}m. Faced with apparently new workplace conditions, these actions were appropriate and ensured a cautionary approach to worker protection. As additional bioassay data were accumulated, it became apparent that the data were not consistent with Publication 54. Therefore, this study was undertaken to examine the situation.

  20. Effects of chronic exposure to environmentally relevant concentrations of waterborne depleted uranium on the digestive tract of zebrafish, Danio rerio

    International Nuclear Information System (INIS)

    Uranium is a naturally occurring element, but activities linked to the nuclear fuel cycle can increase background levels in the surrounding waters. For this reason it is important to understand how this affects organisms residing in the water column. The objective of this study was to assess histopathological effects of uranium on the gut wall of a widely used model organism: zebrafish, Danio rerio. To this end we exposed zebrafish to 84 and 420 nM depleted uranium for over a month and then examined the histology of intestines of exposed individuals compared to controls. The gut wall of individuals exposed to 84 and 420 nM of uranium had large regions of degraded mucosa. Using transmission electron microscopy (TEM) coupled to energy-dispersive X-ray spectroscopy microanalysis (EDX) we found that uranium induced a decrease in the amount of calcium containing mitochondrial matrix granules per mitochondria. This is suggestive of perturbations to cellular metabolism and more specifically to cellular calcium homeostasis. TEM-EDX of the gut wall tissue further showed that some uranium was internalized in the nucleus of epithelial cells in the 420 nM treatment. Fluorescent in situ hybridization using specific probes to detect all eubacteria was performed on frozen sections of 6 individual fish in the 84 nM and 420 nM treatments. Bacterial colonization of the gut of individuals in the 420 nM seemed to differ from that of the controls and 84 nM individuals. We suggest that host–microbiota interactions are potentially disturbed in response to uranium induced stress. The damage induced by waterborne uranium to the gut wall did not seem to depend on the concentration of uranium in the media. We measure whole body residues of uranium at the end of the experiment and compute the mean dose rate absorbed for each condition. We discuss why effects might be uncoupled from external concentration and highlight that it is not so much the external concentration but the dynamics

  1. Leukaemia among uranium miners - late effects of exposure to uranium dust

    International Nuclear Information System (INIS)

    This paper deals with on recent observations among Czech uranium miners by 1999. Results of leukaemia study in a cohort of nearly 10 000 uranium miners based on 29 observed cases show significant association to chronic exposure. The largest contribution is from the uranium dust. Although there are estimates to the red bone marrow, it seems to be more practical to use a model based on modified duration of exposure, where non-hewer exposure are accounted by 50%. The evaluation of leukaemia subtypes is limited by low numbers. More accurate results can be expected in an extended follow-up or by pooling several studies. (authors)

  2. Effects of chronic exposure to environmentally relevant concentrations of waterborne depleted uranium on the digestive tract of zebrafish, Danio rerio.

    Science.gov (United States)

    Augustine, Starrlight; Pereira, Sandrine; Floriani, Magali; Camilleri, Virginie; Kooijman, Sebastiaan A L M; Gagnaire, Béatrice; Adam-Guillermin, Christelle

    2015-04-01

    Uranium is a naturally occurring element, but activities linked to the nuclear fuel cycle can increase background levels in the surrounding waters. For this reason it is important to understand how this affects organisms residing in the water column. The objective of this study was to assess histopathological effects of uranium on the gut wall of a widely used model organism: zebrafish, Danio rerio. To this end we exposed zebrafish to 84 and 420 nM depleted uranium for over a month and then examined the histology of intestines of exposed individuals compared to controls. The gut wall of individuals exposed to 84 and 420 nM of uranium had large regions of degraded mucosa. Using transmission electron microscopy (TEM) coupled to energy-dispersive X-ray spectroscopy microanalysis (EDX) we found that uranium induced a decrease in the amount of calcium containing mitochondrial matrix granules per mitochondria. This is suggestive of perturbations to cellular metabolism and more specifically to cellular calcium homeostasis. TEM-EDX of the gut wall tissue further showed that some uranium was internalized in the nucleus of epithelial cells in the 420 nM treatment. Fluorescent in situ hybridization using specific probes to detect all eubacteria was performed on frozen sections of 6 individual fish in the 84 nM and 420 nM treatments. Bacterial colonization of the gut of individuals in the 420 nM seemed to differ from that of the controls and 84 nM individuals. We suggest that host-microbiota interactions are potentially disturbed in response to uranium induced stress. The damage induced by waterborne uranium to the gut wall did not seem to depend on the concentration of uranium in the media. We measure whole body residues of uranium at the end of the experiment and compute the mean dose rate absorbed for each condition. We discuss why effects might be uncoupled from external concentration and highlight that it is not so much the external concentration but the dynamics of

  3. Chronic radionuclide low dose exposure for non-human biota: challenges in establishing links between speciation in the exposure sources, bioaccumulation and biological effects. Uranium in aquatic ecosystems: A case-study

    International Nuclear Information System (INIS)

    In the field of environmental radioprotection, the knowledge gaps concern situations leading to chronic exposure at the lower doses typical of the living conditions of organisms influenced by radioactive releases. For any radionuclide and ecosystem, the specificities of these situations are as followed: (i) various chemical forms occur in the environment as a function of the physico-chemical conditions of the medium; (ii) each transfer from one component to another can lead to a modification of these forms with a 'chemical form-specific' mobility and bioavailability; (iii) different categories of non-radioactive toxicants are simultaneously present. In this multipollution context, the biological effects of ionising radiation may be exacerbated or reduced with the potential for action or interaction of all the pollutants present simultaneously. These situations of chronic exposure at low levels are likely to cause toxic responses distinct from those observed after acute exposure at high doses since long-term accumulation mechanisms in cells and tissues may lead to microlocalised accumulation in some target cells or subcellular components. The assessment of these mechanisms is primordial with regard to internal exposure to radionuclides since they increase locally both the radionuclide concentration and the delivered dose, coupling radiological and chemical toxicity. This is the main purpose of the ENVIRHOM research programme, recently launched at IRSN. After a global overview of the experimental strategy and of the first results obtained for phytoplankton and uranium, this paper scans the state of art for uranium within freshwaters and underlines inconsistency encountered when one wants to carry out an Ecological Risk Assessment (ERA) on the chemical or on the radiological standpoint. This example argues for future research needs in order to establish well-defined relationship between chemo-toxicity and radiotoxicity for internal contamination. The operational aim

  4. Assessment of exposure to depleted uranium

    International Nuclear Information System (INIS)

    In most circumstances, measurement of uranium excreted in urine at known times after exposure is potentially the most sensitive method for determining the amount of depleted uranium (DU) incorporated. The problems associated with this approach are that natural uranium is always present in urine because of the ingestion of natural uranium in food and drink, and that the uncertainties in the intakes as assessed from excretion measurements can be quite large, because many assumptions concerning the exposure characteristics (time pattern of exposure, route of intake, chemical form, solubility, biokinetics within the body) must be made. Applying currently available methods and instruments for the measurement of uranium in urine samples, DU incorporations of levels relevant with respect to potential health hazards can be detected reliably, even a long time after exposure. (author)

  5. Chronic exposure to uranium compounds: medical surveillance problems related to their physico-chemical properties and their solubility: actual data and future prospects

    International Nuclear Information System (INIS)

    A method was developped to assess uranium exposure hazards at work stations based on industrial experience acquired in Comurhex Malvesi at Narbonne. Applied to uranium tetrafluoride (UF4), the method involves five steps: 1/ Characterization of the industrial compound, including physico-chemical properties (density, surface area, X-ray spectrum and uranium enrichment). 2/ In vitro biological solubility with different synthetic fluids like Gamble solution added with differents gaz or compounds (Oxygen or hydrogen peroxyde), in order to determine the solubility class D, W or Y. 3/ Assessment of work station concentration in Bq m-3 and particle size distribution (AMAD). 4/ Monitoring workers by routine urinary excretion completed, if necessary, by fecal excretion and γ spectrometry. 5/ Use of individual protection filters or masks. Results and actual data on UF4 are presented and future prospects of studies on calcinated uranates are dealed with

  6. In Vivo Nanodetoxication for Acute Uranium Exposure

    Directory of Open Access Journals (Sweden)

    Luis Guzmán

    2015-06-01

    Full Text Available Accidental exposure to uranium is a matter of concern, as U(VI is nephrotoxic in both human and animal models, and its toxicity is associated to chemical toxicity instead of radioactivity. We synthesized different PAMAM G4 and G5 derivatives in order to prove their interaction with uranium and their effect on the viability of red blood cells in vitro. Furthermore, we prove the effectiveness of the selected dendrimers in an animal model of acute uranium intoxication. The dendrimer PAMAM G4-Lys-Fmoc-Cbz demonstrated the ability to chelate the uranyl ion in vivo, improving the biochemical and histopathologic features caused by acute intoxication with uranium.

  7. Bringing together Scientific Disciplines to better understand the health effects of Occupational Exposure to uranium

    International Nuclear Information System (INIS)

    Knowledge regarding the effects of chronic exposure to uranium comes up against the limitations specific to each discipline that takes an interest. The CURE (Concerted Uranium Research in Europe) project offers a scientific approach combining epidemiology, biology, toxicology and dosimetry to go beyond these limitations. (author)

  8. Emergency exposure levels for natural uranium

    International Nuclear Information System (INIS)

    An attempt is made to identify the inhalation hazards associated with the over-exposure of workers and of the general public, following an accidental release of uranium hexafluoride. Maximum emergency concentrations are recommended for periods of 10, 30, and 60 minutes. The quantitative aspect of the assessment is considered in the context of the development of exposure standards for chemical substances and this facilitates the derivation of levels which are compatible with occupational and public health experience and attainable by management, and to which most workers and members of the general public may be exposed without adverse effect. The radiological implications are also considered. (author)

  9. Radon daughter exposure to uranium miners

    International Nuclear Information System (INIS)

    Radon exposures to U.S. uranium miners average about 1.3 WLM per year approximately equal to 60 WLM per full working lifetime. This is intermediate between (a) the lowest exposures for which there have been excess lung cancers reported among U.S. miners (120-240 WLM) and (b) average environmental radon exposures (16 WLM), so models based on these two situations are used to estimate expected effects on present uranium miners. In Model A, the loss of life expectancy is 45 days, the SMR (standardized mortality ratio) for lung cancer is 1.10, and the SMR for all causes between ages 18 and 65 is 1.013. In Model B these are 10 days, 1.03 and 1.002 respectively. It is shown that the radon exposures to miners are similar to those to millions of Americans from environmental exposure, and that miner health risks are comparable to those of other radiation workers. Their lung cancer risk from radon is 7-50 times less than their job-related accident mortality risk, and represents 0.7-4% of their total risk in mining. Miners suffer from many diseases with SMR very much larger than that for radon-induced lung cancer. (author)

  10. Compared biokinetic and biological studies of chronic and acute inhalations of uranium compounds in the rat

    International Nuclear Information System (INIS)

    Uranium is a natural, radioactive heavy metal, widely used in the nuclear industry in various chemical and isotopic forms. Its use in the fuel cycle involves the risk of radiological exposure for the workers, mainly via the inhalation of uranium particles. According to the workplace configuration, uranium contaminations can be acute or repeated, involve various chemical forms and different levels of enrichment, as well as involving one or several components. The dosimetric concepts and models available for workers' radiological protection, as well as most of the studies of the biological effects, correspond to acute exposure situations. Moreover the processes leading to pathological effects are little known in vivo. In this context, the main question is to know whether exposures due to repeated inhalation by rats induce the element kinetics and toxicity, which may be different from those observed after an acute exposure. In this study, comparison of the experimental and theoretical biokinetics of an insoluble uranium repeatedly inhaled over three weeks shows that a chronic contamination is correctly modelled, except for bone retention, by the sum of acute, successive and independent incorporations. Moreover, the kinetics of a soluble uranium inhaled irregularly can be modified by previous repeated exposure to an insoluble uranium. In certain cases therefore, exposure to uranium could modify its biokinetics during later exposures. At a toxicological level, the study demonstrates that the uranium particles inhaled repeatedly induce behavioural disruptions and genotoxic effects resulting in various sorts of DNA damage, in several cell types and certainly depending on the quantity inhaled. Exposures involving several uraniferous components produce a synergy effect. Moreover, repeated inhalations worsen the genotoxic effects in comparison to an acute exposure. This work demonstrates the importance of not ignoring the effects of the repetition of uranium exposure. It

  11. Effect of nephrotoxic treatment with gentamicin on rats chronically exposed to uranium

    International Nuclear Information System (INIS)

    Uranium is a radioactive heavy metal with a predominantly chemical toxicity, affecting especially the kidneys and more particularly the proximal tubular structure. Until now, few experimental studies have examined the effect of chronic low-dose exposure to uranium on kidney integrity: these mainly analyse standard markers such as creatinine and urea, and none has studied the effect of additional co-exposure to a nephrotoxic agent on rats chronically exposed to uranium. The aim of the present study is to examine the potential cumulative effect of treating uranium-exposed rats with a nephrotoxic drug. Neither physiological indicators (diuresis and creatinine clearance) nor standard plasma and urine markers (creatinine, urea and total protein) levels were deteriorated when uranium exposure was combined with gentamicin-induced nephrotoxicity. A histological study confirmed the preferential impact of gentamicin on the tubular structure and showed that uranium did not aggravate the histopathological renal lesions. Finally, the use of novel markers of kidney toxicity, such as KIM-1, osteopontin and kallikrein, provides new knowledge about the nephrotoxicity threshold of gentamicin, and allows us to conclude that under our experimental conditions, low dose uranium exposure did not induce signs of nephrotoxicity or enhance renal sensitivity to another nephrotoxicant.

  12. Uranium internal exposure evaluation based on urine assay data

    International Nuclear Information System (INIS)

    The difficulties in assessing internal exposures to uranium from urine assay data are described. A simplified application of the ICRP-30 and ICRP Lung Model concepts to the estimation of uranium intake is presented. A discussion follows on the development of a computer code utilizing the ICRP-30-based uranium elimination model with the existing urine assay information. The calculated uranium exposures from 1949 through 1983 are discussed. 13 references, 1 table

  13. Uranium chronic contamination effects on the cholinergic system: in vivo and in vitro approaches

    International Nuclear Information System (INIS)

    Uranium (U) is a heavy metal which occurs naturally in the environment. It is both a chemical and a radiological toxicant. The aim of this work was: (i) to assess the effects of U chronic exposure on the cholinergic system (biosynthesis and breakdown enzymes, receptors and on behaviour of adult, young or predisposed to neuro-degenerative illness (ApoE KO) rodents; (ii) to grasp the neurotoxic effects of U on human neuronal cells. In vivo, this work shows a structure- (cortex more sensitive than hippocampus), rodent model- (young more sensitive than adults), time- (sub-chronic exposure more harmful than chronic exposure), exposure level- and isotope-dependent effect of U. In vitro, the study underlined the neuro-cytotoxic U potential and the presence of uranium precipitates in cells. These results show the deleterious impact of U on neuronal cells, and demonstrate that U induces impairments on the cholinergic system and the behaviour of rodents. (author)

  14. Chemical and radiological effects of chronic ingestion of uranium in the rat brain: biochemical impairment of dopaminergic, serotonergic and cholinergic neuro-transmissions

    International Nuclear Information System (INIS)

    Uranium is an environmental ubiquitous metal-trace element. It has both chemical and radiological toxicity. After chronic ingestion, uranium can distribute in any part of the body and accumulate in the brain. The aims of this study was 1) to determine and estimate the effects of uranium on dopaminergic, serotoninergic and cholinergic systems and 2) to measure the uranium amount in the brain, after chronic exposure by ingestion of depleted (D.U.) or enriched (E.U.) uranium during 1.5 to 18 months at 40 mg.L-1 (40 ppm) in different rat brain areas. At any time of exposure, the results show that both the neurotransmission alterations and the uranium brain accumulation were moderate, area specific, time-evolutive and depended on uranium specific activity. After D.U. exposure, monoamine perturbations are chronic and progressive. On the contrary, monoamine alterations occurred only after long term of E.U. exposure. These mono-aminergic modifications are not always dependent on uranium accumulation in brain areas. Moreover, although the cholinergic system was not affected at both 1.5 and 9 months of D.U. exposure, the alteration of ChE activity after E.U. exposure are both dependent on uranium accumulation in brain areas and on uranium specific activity. After E.U. exposure, cholinergic modification and uranium accumulation in hippocampus could partially explain the short-term memory disturbances which have been previously reported. (author)

  15. Concerted Uranium Research in Europe (CURE): toward a collaborative project integrating dosimetry, epidemiology and radiobiology to study the effects of occupational uranium exposure.

    Science.gov (United States)

    Laurent, Olivier; Gomolka, Maria; Haylock, Richard; Blanchardon, Eric; Giussani, Augusto; Atkinson, Will; Baatout, Sarah; Bingham, Derek; Cardis, Elisabeth; Hall, Janet; Tomasek, Ladislav; Ancelet, Sophie; Badie, Christophe; Bethel, Gary; Bertho, Jean-Marc; Bouet, Ségolène; Bull, Richard; Challeton-de Vathaire, Cécile; Cockerill, Rupert; Davesne, Estelle; Ebrahimian, Teni; Engels, Hilde; Gillies, Michael; Grellier, James; Grison, Stephane; Gueguen, Yann; Hornhardt, Sabine; Ibanez, Chrystelle; Kabacik, Sylwia; Kotik, Lukas; Kreuzer, Michaela; Lebacq, Anne Laure; Marsh, James; Nosske, Dietmar; O'Hagan, Jackie; Pernot, Eileen; Puncher, Matthew; Rage, Estelle; Riddell, Tony; Roy, Laurence; Samson, Eric; Souidi, Maamar; Turner, Michelle C; Zhivin, Sergey; Laurier, Dominique

    2016-06-01

    The potential health impacts of chronic exposures to uranium, as they occur in occupational settings, are not well characterized. Most epidemiological studies have been limited by small sample sizes, and a lack of harmonization of methods used to quantify radiation doses resulting from uranium exposure. Experimental studies have shown that uranium has biological effects, but their implications for human health are not clear. New studies that would combine the strengths of large, well-designed epidemiological datasets with those of state-of-the-art biological methods would help improve the characterization of the biological and health effects of occupational uranium exposure. The aim of the European Commission concerted action CURE (Concerted Uranium Research in Europe) was to develop protocols for such a future collaborative research project, in which dosimetry, epidemiology and biology would be integrated to better characterize the effects of occupational uranium exposure. These protocols were developed from existing European cohorts of workers exposed to uranium together with expertise in epidemiology, biology and dosimetry of CURE partner institutions. The preparatory work of CURE should allow a large scale collaborative project to be launched, in order to better characterize the effects of uranium exposure and more generally of alpha particles and low doses of ionizing radiation. PMID:27183135

  16. Occupational Exposures and Chronic Airflow Limitation

    Directory of Open Access Journals (Sweden)

    Helen Dimich-Ward

    1996-01-01

    Full Text Available The recent literature was reviewed to evaluate whether chronic airflow limitation is associated with occupational exposures to dusts. Only those studies that controlled for the effects of smoking were included. There is compelling evidence that exposure to inorganic dusts, such as from coal and hardrock mining or asbestos, are associated with the development of chronic airflow limitation, independently of pneumoconiosis. Nonsmoking gold miners are particularly at high risk of airflow obstruction and emphysema. Findings from studies of organic dusts, such as exposures to wood, cotton, grain or other agricultural dusts, or to mixed dust exposures, were less consistent but tended to show positive dose-response associations. In the majority of studies, no statistical interaction was shown between dust exposures and smoking; however, the effects of the dust exposures were often more pronounced. An occupational history should be considered, in addition to a smoking history, as an integral part of an investigation of chronic airflow limitation in a patient.

  17. From cell to man: Evaluation of osteopontin as a possible bio-marker of uranium exposure

    International Nuclear Information System (INIS)

    Background: Ore workers are conventionally monitored for exposure by measuring the uranium in their urine, but specific bio-markers of kidney damage still remain to be discovered. A recent toxico-genomics study allowed us to focus on osteopontin (OSTP) normally excreted in human urine and linked to mineral metabolism. Objectives: We examined the association between osteopontin and uranium exposure both in vitro, in a human kidney cell model, and in the urine of exposed individuals. Methods: OSTP was measured in supernatants of uranium-exposed HK2 cells to establish a dose-response curve and a time course experiment. Its role was studied through a gene extinction experiment. Uranium and OSTP were then monitored in the urine of exposed nuclear fuel industry workers and a chronically exposed population. These levels were compared with those found in a non-exposed population. Results: The study of HK2 cells indicated that OSTP secretion decreased after uranium exposure in a concentration and time dependent manner, but its suppression does not affect cell sensitivity to uranium. In spite of wide inter-individual variability, this parameter decreases also in human urine when urinary uranium exceeds 30 μg/L after an acute exposure, a value considered to be critical for kidney damage. Conclusion: This study reports how toxico-genomics can highlight putative toxicity bio-markers in an easy to access biological fluid. The decrease of urinary osteopontin in response to uranium exposure suggests kidney damage and would thus be complementary to current markers. (authors)

  18. Occupational exposures to uranium: processes, hazards, and regulations

    International Nuclear Information System (INIS)

    The United States Uranium Registry (USUR) was formed in 1978 to investigate potential hazards from occupational exposure to uranium and to assess the need for special health-related studies of uranium workers. This report provides a summary of Registry work done to date. The history of the uranium industry is outlined first, and the current commercial uranium industry (mining, milling, conversion, enrichment, and fuel fabrication) is described. This description includes information on basic processes and areas of greatest potential radiological exposure. In addition, inactive commercial facilities and other uranium operations are discussed. Regulation of the commercial production industry for uranium fuel is reported, including the historic development of regulations and the current regulatory agencies and procedures for each phase of the industry. A review of radiological health practices in the industry - facility monitoring, exposure control, exposure evaluation, and record-keeping - is presented. A discussion of the nonradiological hazards of the industry is provided, and the final section describes the tissue program developed as part of the Registry

  19. Internal distribution of uranium and associated genotoxic damages in the chronically exposed bivalve Corbicula fluminea

    Energy Technology Data Exchange (ETDEWEB)

    Simon, Olivier, E-mail: olivier.simon@irsn.fr [Laboratoire de Radioecologie et Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat, 186 BP3, 13115 Saint Paul-Lez-Durance Cedex (France); Floriani, Magali; Cavalie, Isabelle; Camilleri, Virginie; Adam, Christelle; Gilbin, Rodolphe; Garnier-Laplace, Jacqueline [Laboratoire de Radioecologie et Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat, 186 BP3, 13115 Saint Paul-Lez-Durance Cedex (France)

    2011-08-15

    Uranium (U) internal distribution and involved effects in the bivalve Corbicula fluminea have been studied after direct chronic exposure (90 d, 10 {mu}g.L-1). U distribution was assessed at the subcellular level (Metal Rich Granules -MRG-, pellets and cytosol fractions) in two main organs of the bivalve (gills and visceral mass). Micro-localisation was investigated by TEM-EDX analysis in the gills epithelium. DNA damage in gill and hemolymph samples was measured by the Comet assay. The 90-d exposure period led to a significant increase of U concentration in gills over time (x5) and a large U quantity in subcellular granules in gills. Finally, a significant increase (x2) in DNA damage was noted in exposed gills and haemocytes. This study shows that the accumulation levels and consequently the potential toxicity cannot be successfully predicted only on the basis of concentration in water or in tissues and subcellular fractions after chronic exposure. - Highlights: > Relevant information concerning the chronic impact of uranium on biota is scarce. > We study its biological speciation to explain bioavailability, accumulation, toxicity. > 80% of U accumulated was measured in the pellet fraction (organelles + granules/MRG). > Chronic exposure to U induced genetic damage in gill and haemolymph cells of the bivalve.

  20. Internal exposure to uranium in a pooled cohort of gaseous diffusion plant workers

    International Nuclear Information System (INIS)

    Intakes and absorbed organ doses were estimated for 29 303 workers employed at three former US gaseous diffusion plants as part of a study of cause-specific mortality and cancer incidence in uranium enrichment workers. Uranium urinalysis data (>600 000 urine samples) were available for 58 % of the pooled cohort. Facility records provided uranium gravimetric and radioactivity concentration data and allowed estimation of enrichment levels of uranium to which workers may have been exposed. Urine data were generally recorded with facility department numbers, which were also available in study subjects' work histories. Bioassay data were imputed for study subjects with no recorded sample results (33 % of pooled cohort) by assigning department average urine uranium concentration. Gravimetric data were converted to 24-h uranium activity excretion using department average specific activities. Intakes and organ doses were calculated assuming chronic exposure by inhalation to a 5-μm activity median aerodynamic diameter aerosol of soluble uranium. Median intakes varied between 0.31 and 0.74 Bq d-1 for the three facilities. Median organ doses for the three facilities varied between 0.019 and 0.051, 0.68 and 1.8, 0.078 and 0.22, 0.28 and 0.74, and 0.094 and 0.25 mGy for lung, bone surface, red bone marrow, kidneys, and liver, respectively. Estimated intakes and organ doses for study subjects with imputed bioassay data were similar in magnitude. (authors)

  1. Does uranium exposure induce oxidative stress and genotoxicity in the teleostean Danio rerio? first experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Barillet, S.; Devaux, A.; Simon, O.; Buet, A.; Pradines, C. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

    2004-07-01

    Within the Envirhom research program, key advances have been obtained in uranium bioaccumulation and underlying mechanisms understanding in various biological models at the individual level. However, considering different scales of biological effects (from early to delayed ones, from low to high level of organization) is crucial to provide ecologically relevant indicators. Organisms counteract stress induced by pollutant exposure through a wide range of physiological responses being both dose and time dependent. Effects at higher hierarchical levels are always preceded by early changes in biological processes, from subtle biochemical disturbances to impaired physiological functions, increased susceptibility to other stresses, reduced life-span Within this global context, preliminary experiments were carried out on adult zebra fish (Danio rerio), to assess early changes after short-term uranium exposure. Among the subsequent primary subcellular damages oxidative stress and genotoxicity (characterizing both chemo-toxicity and radiotoxicity) are relevant endpoints, thus requiring the knowledge of dose-effects relationships as a first operational approach to provide useful tool in predicting possible effects of U exposure. Zebra fish has been selected due to its small size (facilitating its maintenance) and its extended use in eco-toxicological studies. Moreover, its short life-cycle will allow to carry out chronic exposure experiments (along the whole life-cycle). Four uranium concentrations (0, 20, 100 and 500{mu}g.L{sup -1}) and five sampling times (0, 0.5, 1, 5 and 10 days) were selected. Catalase, glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were measured as oxidative stress bio-markers. DNA damage level was assessed in zebra fish erythrocytes using the comet assay. Uranium bioaccumulation was concurrently studied to understand observed bio-marker responses. Further experiments, dedicated to the assessment of the impact of chronic uranium

  2. Does uranium exposure induce oxidative stress and genotoxicity in the teleostean Danio rerio? first experimental results

    International Nuclear Information System (INIS)

    Within the Envirhom research program, key advances have been obtained in uranium bioaccumulation and underlying mechanisms understanding in various biological models at the individual level. However, considering different scales of biological effects (from early to delayed ones, from low to high level of organization) is crucial to provide ecologically relevant indicators. Organisms counteract stress induced by pollutant exposure through a wide range of physiological responses being both dose and time dependent. Effects at higher hierarchical levels are always preceded by early changes in biological processes, from subtle biochemical disturbances to impaired physiological functions, increased susceptibility to other stresses, reduced life-span Within this global context, preliminary experiments were carried out on adult zebra fish (Danio rerio), to assess early changes after short-term uranium exposure. Among the subsequent primary subcellular damages oxidative stress and genotoxicity (characterizing both chemo-toxicity and radiotoxicity) are relevant endpoints, thus requiring the knowledge of dose-effects relationships as a first operational approach to provide useful tool in predicting possible effects of U exposure. Zebra fish has been selected due to its small size (facilitating its maintenance) and its extended use in eco-toxicological studies. Moreover, its short life-cycle will allow to carry out chronic exposure experiments (along the whole life-cycle). Four uranium concentrations (0, 20, 100 and 500μg.L-1) and five sampling times (0, 0.5, 1, 5 and 10 days) were selected. Catalase, glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were measured as oxidative stress bio-markers. DNA damage level was assessed in zebra fish erythrocytes using the comet assay. Uranium bioaccumulation was concurrently studied to understand observed bio-marker responses. Further experiments, dedicated to the assessment of the impact of chronic uranium

  3. Monitoring genotoxic exposure in uranium mines

    International Nuclear Information System (INIS)

    Recent data from deep uranium mines in Czechoslovakia indicated that miners are exposed to other mutagenic factors in addition to radon daughter products. Mycotoxins were identified as a possible source of mutagens in these mines. Mycotoxins were examined in 38 samples from mines and in throat swabs taken from 116 miners and 78 controls. The following mycotoxins were identified from mines samples: aflatoxins B1 and G1, citrinin, citreoviridin, mycophenolic acid, and sterigmatocystin. Some mold strains isolated from mines and throat swabs were investigated for mutagenic activity by the SOS chromotest and Salmonella assay with strains TA100 and TA98. Mutagenicity was observed, especially with metabolic activation in citro. These data suggest that mycotoxins produced by molds in uranium mines are a new genotoxic factor im uranium miners. 17 refs., 4 tabs

  4. Absorption kinetics of uranium tri-n-butyl phosphate in the rat. Implications for occupational exposure

    International Nuclear Information System (INIS)

    The absorption kinetics for uranium into blood after deposition as tri-n-butylphosphate (UTBP) in the rat lung were combined with human data on particle deposition and clearance from the ICRP Publication 66 respiratory tract model and information from the most recent ICRP biokinetic model for uranium to predict the consequences for exposure of workers. These predictions suggest that, (1) the biokinetics of UTBP are similar to those for a Type F compound as defined by ICRP, (2) the dose coefficient is essentially independent of the aerosol size and isotopic composition, (3) the mass of uranium equivalent to the ALI can vary by 13 fold depending upon the isotopic composition, (4) intakes of uranium as UTBP other than chronic intakes as highly enriched forms should be restricted on the basis of the chemical toxicity of uranium, (5) the assessment of intake by urine bioassay measurements should be interpreted with caution unless the exposure conditions are well defined and (6) severe kidney damage is unlikely at intakes corresponding to the ALI or daily limit. (author)

  5. Monitoring genotoxic exposure in uranium mines.

    OpenAIRE

    Srám, R J; Dobiás, L; Rössner, P; Veselá, D; Veselý, D; Rakusová, R; V. Rericha

    1993-01-01

    Recent data from deep uranium mines in Czechoslovakia indicated that mines are exposed to other mutagenic factors in addition to radon daughter products. Mycotoxins were identified as a possible source of mutagens in these mines. Mycotoxins were examined in 38 samples from mines and in throat swabs taken from 116 miners and 78 controls. The following mycotoxins were identified from mines samples: aflatoxins B1 and G1, citrinin, citreoviridin, mycophenolic acid, and sterigmatocystin. Some mold...

  6. Chemical and radiological effects of chronic ingestion of uranium in the rat brain: biochemical impairment of dopaminergic, serotonergic and cholinergic neuro-transmissions; Effets chimique et radiologique d'une ingestion chronique d'uranium sur le cerveau du rat. Effets sur les neurotransmissions dopaminergique, serotoninergique et cholinergique

    Energy Technology Data Exchange (ETDEWEB)

    Bussy, C

    2005-09-15

    Uranium is an environmental ubiquitous metal-trace element. It has both chemical and radiological toxicity. After chronic ingestion, uranium can distribute in any part of the body and accumulate in the brain. The aims of this study was 1) to determine and estimate the effects of uranium on dopaminergic, serotoninergic and cholinergic systems and 2) to measure the uranium amount in the brain, after chronic exposure by ingestion of depleted (D.U.) or enriched (E.U.) uranium during 1.5 to 18 months at 40 mg.L{sup -1} (40 ppm) in different rat brain areas. At any time of exposure, the results show that both the neurotransmission alterations and the uranium brain accumulation were moderate, area specific, time-evolutive and depended on uranium specific activity. After D.U. exposure, monoamine perturbations are chronic and progressive. On the contrary, monoamine alterations occurred only after long term of E.U. exposure. These mono-aminergic modifications are not always dependent on uranium accumulation in brain areas. Moreover, although the cholinergic system was not affected at both 1.5 and 9 months of D.U. exposure, the alteration of ChE activity after E.U. exposure are both dependent on uranium accumulation in brain areas and on uranium specific activity. After E.U. exposure, cholinergic modification and uranium accumulation in hippocampus could partially explain the short-term memory disturbances which have been previously reported. (author)

  7. Depleted uranium exposure and health effects in Gulf War veterans

    OpenAIRE

    Squibb, Katherine S.; McDiarmid, Melissa A.

    2006-01-01

    Health effects stemming from depleted uranium (DU) exposure in a cohort of Gulf War veterans who were in or on US Army vehicles hit by friendly fire involving DU munitions are being carefully monitored through the Baltimore Veterans Affairs (VA) DU Follow-Up Program initiated in 1993. DU exposure in this cohort has been directly measured using inductively coupled plasma-mass spectrometer (ICP-MS) isotopic analysis for DU in urine specimens. Soldiers with embedded DU fragments continue to excr...

  8. Biological consequences of exposure to soluble forms of natural uranium

    International Nuclear Information System (INIS)

    Depending on dose, route of administration and chemical form of the administered uranium, exposure to uranium compounds can produce effects in a variety of organs. Of these, the kidney is the most sensitive, and is considered to be a critical target organ for hazard assessment. Although dose-effect relationships differ among species, injury and necrosis of the terminal segments of the renal proximal tubule is characteristic in all mammalian species that have been studied. Glomerular injury has also been reported. The critical occupational health issues is thus, ''To what extent can laboratory animal models be useful for predicting human health hazards to uranium?''. While direct quantitative extrapolations of dose-effect relationships in laboratory animals to humans is not a reality at present, it is possible, nevertheless, to explore in laboratory animal models certain specific questions regarding the biological effects of uranium in kidney that are relevant to hazard assessment. Indeed, a complete understanding of the laboratory animal model is critical for establishing valid extrapolations to humans. Issues relating to mechanisms of renal injury, dose-effect relationships and biological monitoring for uranium-induced nephrotoxicity are considered in this review. (author)

  9. Agricultural versus uranium industry regarding the exposure to natural radiation

    International Nuclear Information System (INIS)

    The potential exposure of the critical group is to be evaluated against national and international recommendation regarding the impact of general nuclear facilities. In Brazil, an agricultural industry together with uranium mining and milling facilities take place at an elevated natural radioactivity region. It was performed a dose and risk assessment to the local and remote population due to these two man made activities. This paper will present some data on dose and radiological risk to the local population (rural workers and their families) living at that region for occupational reasons. The non significant increase on the radiation dose exposure to a critical group due to the uranium industry will be pointed out. Problems associated in applying the ICRP dose limitation system to such situations will be discussed. (author)

  10. Military use of depleted uranium: assessment of prolonged population exposure

    OpenAIRE

    Giannardi, C.; Dominici, D.

    2001-01-01

    This work is an exposure assessment for a population living in an area contaminated by use of depleted uranium (DU) weapons. RESRAD 5.91 code is used to evaluate the average effective dose delivered from 1, 10, 20 cm depths of contaminated soil, in a residential farmer scenario. Critical pathway and group are identified in soil inhalation or ingestion and children playing with the soil, respectively. From available information on DU released on targeted sites, both critical and average exposu...

  11. Secondary limits of exposure in facilities handling uranium

    International Nuclear Information System (INIS)

    Annual limits of exposure and intake for radiation workers in nuclear installations have been recommended by the International Commission on Radiological Protection and the same have been adopted by the Indian Atomic Energy Regulatory Board for all the radionuclides of interest. The prescribed limits cannot be directly used for day to day radiation protection work. Hence secondary limits have to be derived for routine applications. The modeling steps may be simple in some situations and more complicated in some others. The limits recommended are for individual radionuclides. But in facilities handling natural or enriched uranium the radionuclides (isotopes of uranium and its decay products) generally occur together in specific ratios. Derivation of secondary limits has to take this into consideration. The present document is an attempt at deriving the secondary limits required for routine application in facilities handling uranium (Mine, mill, refineries and fuel fabrication etc.). Secondary limits of exposure have been derived in this document for air borne activity, activity in water, surface contamination and internal exposures. (author)

  12. Proteome changes in rat serum after a chronic ingestion of enriched uranium: Toward a biological signature of internal contamination and radiological effect.

    Science.gov (United States)

    Petitot, F; Frelon, S; Chambon, C; Paquet, F; Guipaud, O

    2016-08-22

    The civilian and military use of uranium results in an increased risk of human exposure. The toxicity of uranium results from both its chemical and radiological properties that vary with isotopic composition. Validated biomarkers of health effects associated with exposure to uranium are neither sensitive nor specific to uranium radiotoxicity and/or radiological effect. This study aimed at investigating if serum proteins could be useful as biomarkers of both uranium exposure and radiological effect. Male Sprague-Dawley rats were chronically exposed through drinking water to low levels (40mg/L, corresponding to 1mg of uranium per animal per day) of either 4% (235)U-enriched uranium (EU) or 12% EU during 6 weeks. A proteomics approach based on two-dimensional electrophoresis (2D-DIGE) and mass spectrometry (MS) was used to establish protein expression profiles that could be relevant for discriminating between groups, and to identify some differentially expressed proteins following uranium ingestion. It demonstrated that the expressions of 174 protein spots over 1045 quantified spots were altered after uranium exposure (puranium contamination and radiological effect. Finally, using bioinformatics tools, pathway analyses of differentially expressed MS-identified proteins find that acute phase, inflammatory and immune responses as well as oxidative stress are likely involved in the response to contamination, suggesting a physiological perturbation, but that does not necessarily lead to a toxic effect. PMID:27267564

  13. Effects in Plant Populations Resulting from Chronic Radiation Exposure

    Energy Technology Data Exchange (ETDEWEB)

    Geras' kin, Stanislav A.; Volkova, Polina Yu.; Vasiliyev, Denis V.; Dikareva, Nina S.; Oudalova, Alla A. [Russian Institute of Agricultural Radiology and Agroecology, 249032, Obninsk (Russian Federation)

    2014-07-01

    Human industrial activities have left behind a legacy of ecosystems strongly impacted by a wide range of contaminants, including radionuclides. Phyto-toxic effects of acute impact are well known, but the consequences of long-term chronic exposure to low pollutant concentrations is neither well understood nor adequately included in risk assessments. To understand effects of real-world contaminant exposure properly we must pay attention to what is actually going on in the field. However, for many wildlife groups and endpoints, there are no, or very few, studies that link accumulation, chronic exposure and biological effects in natural settings. To fill the gaps, results of field studies carried out on different plant species (winter rye and wheat, spring barley, oats, Scots pine, wild vetch, crested hair-grass) in various radioecological situations (nuclear weapon testing, the Chernobyl accident, uranium and radium processing) to investigate effects of long-term chronic exposure to radionuclides are discussed. Because each impacted site developed in its own way due to a unique history of events, the experience from one case study is rarely directly applicable to another situation. In spite of high heterogeneity in response, we have detected several general patterns. Plant populations growing in areas with relatively low levels of pollution are characterized by the increased level of both cytogenetic alterations and genetic diversity. Accumulation of cellular alterations may afterward influence biological parameters important for populations such as health and reproduction. Presented data provide evidence that in plant populations inhabiting heavily contaminated territories cytogenetic damage were accompanied by decrease in reproductive ability. In less contaminated sites, because of the scarcity of data available, it is impossible to establish exactly the relationship between cytogenetic effects and reproductive ability. Radioactive contamination of the plants

  14. Risk of lung cancer from radon exposure: contribution of recently published studies of uranium miners

    International Nuclear Information System (INIS)

    The International Commission on Radiological Protection (ICRP) recently estimated the risk of lung cancer associated with radon exposure, and a statement was issued in ICRP Publication 115. This was based on recent epidemiological studies and the results from a joint analysis of cohorts of Czech, French, and German uranium miners, and indicated that the excess relative risk of lung cancer per unit of exposure should be expressed with consideration of chronic exposure over more than 10 years, by modelling time since median exposure, age attained or age at exposure, and taking in account, if possible, interaction between radon and tobacco. The lifetime excess absolute risk (LEAR) calculated from occupational exposure studies is close to 5 × 10−4 per working level month (WLM) (14 × 10−5 per hm J/m3). LEAR values estimated using risk models derived from both miners and domestic exposure studies are in good agreement after accounting for factors such as sex, attained age, and exposure scenario. A sensitivity analysis highlighted the high dependence of background mortality rates on LEAR estimates. Using lung cancer rates among Euro-American males instead of the ICRP reference rates (males and females, and Euro-American and Asian populations), the estimated LEAR is close to 7 × 10−4 per WLM (20 × 10−5 per hm J/m3).

  15. Chronic fatigue syndrome following a toxic exposure.

    Science.gov (United States)

    Racciatti, D; Vecchiet, J; Ceccomancini, A; Ricci, F; Pizzigallo, E

    2001-04-10

    Chronic fatigue syndrome (CFS) is a clinical entity characterized by severe fatigue lasting more than 6 months and other well-defined symptoms. Even though in most CFS cases the etiology is still unknown, sometimes the mode of presentation of the illness implicates the exposure to chemical and/or food toxins as precipitating factors: ciguatera poisoning, sick building syndrome, Gulf War syndrome, exposure to organochlorine pesticides, etc. In the National Reference Center for CFS Study at the Department of Infectious Diseases of 'G. D'Annunzio' University (Chieti) we examined five patients (three females and two males, mean age: 37.5 years) who developed the clinical features of CFS several months after the exposure to environmental toxic factors: ciguatera poisoning in two cases, and exposure to solvents in the other three cases. These patients were compared and contrasted with two sex- and age-matched subgroups of CFS patients without any history of exposure to toxins: the first subgroup consisted of patients with CFS onset following an EBV infection (post-infectious CFS), and the second of patients with a concurrent diagnosis of major depression. All subjects were investigated by clinical examination, neurophysiological and immunologic studies, and neuroendocrine tests. Patients exposed to toxic factors had disturbances of hypothalamic function similar to those in controls and, above all, showed more severe dysfunction of the immune system with an abnormal CD4/CD8 ratio, and in three of such cases with decreased levels of NK cells (CD56+). These findings may help in understanding the pathogenetic mechanisms involved in CFS. PMID:11327394

  16. Epi-genetics modifications induced by a depleted uranium exposure in the zebra fish

    Energy Technology Data Exchange (ETDEWEB)

    Gombeau, K.; Pereira, S.; Adam-Guillermin, C. [IRSN/PRP-ENV/SERIS/LECO (France); Bourdineaud, J.P. [UMR CNRS 5805 EPOC (France); Ravanat, J.L. [INAC/Scib UMR E3 CEA-UJF (France)

    2014-07-01

    The work presented here integrates in the general framework of assessment of effects of chronic exposure to low doses of radionuclides. This evaluation necessarily involves the study of the mechanisms of toxic action at the cellular or subcellular level, in order to better understand the processes of propagation of effects to the level of the populations or ecosystems. As such, the question of the mechanisms underlying the trans-generational effects and the adaptive capacity of organisms is central, both in humans and in animal species. Epigenetic refer to changes in gene function that do not involve changes in DNA sequence, and which are transmitted in a hereditary manner by mitosis or meiosis. The latter plays a key role in these trans-generational effects. Among these changes, DNA-methylation is one of the most studied epigenetic parameters. This work is part of a PhD, included in the European COMET project (Euratom 7. Framework Program), and focuses on epigenetic modifications induced in zebra fish after a chronic exposure to radionuclides. Male and female fishes were exposed to 2 and 20 μg.L{sup -1} of depleted uranium for 24 days. After 7 and 24 days of exposure, brain, gonads, and eyes were collected in order to study changes in DNA methylation. In addition, genotoxicity was measured by the γH2AX assay. The overall changes in DNA methylation were studied by AFLP-MS and HPLC-MS, in order to know if the exposure to depleted uranium changes the global status of DNA methylation. We have found a decrease in the global level of methylation in the eyes of males after 24 days of exposure, the diminution being much more important and significant at the higher concentration of exposure (11.79 ± 3.62 against 52.43 ± 3.01 for controls) This study will be refined by analyzing the methylation of specific regions of the genome, because it represent the sequences of genes involved in major physiological functions and that may be subject to variations in the methylation

  17. Epi-genetics modifications induced by a depleted uranium exposure in the zebra fish

    International Nuclear Information System (INIS)

    The work presented here integrates in the general framework of assessment of effects of chronic exposure to low doses of radionuclides. This evaluation necessarily involves the study of the mechanisms of toxic action at the cellular or subcellular level, in order to better understand the processes of propagation of effects to the level of the populations or ecosystems. As such, the question of the mechanisms underlying the trans-generational effects and the adaptive capacity of organisms is central, both in humans and in animal species. Epigenetic refer to changes in gene function that do not involve changes in DNA sequence, and which are transmitted in a hereditary manner by mitosis or meiosis. The latter plays a key role in these trans-generational effects. Among these changes, DNA-methylation is one of the most studied epigenetic parameters. This work is part of a PhD, included in the European COMET project (Euratom 7. Framework Program), and focuses on epigenetic modifications induced in zebra fish after a chronic exposure to radionuclides. Male and female fishes were exposed to 2 and 20 μg.L-1 of depleted uranium for 24 days. After 7 and 24 days of exposure, brain, gonads, and eyes were collected in order to study changes in DNA methylation. In addition, genotoxicity was measured by the γH2AX assay. The overall changes in DNA methylation were studied by AFLP-MS and HPLC-MS, in order to know if the exposure to depleted uranium changes the global status of DNA methylation. We have found a decrease in the global level of methylation in the eyes of males after 24 days of exposure, the diminution being much more important and significant at the higher concentration of exposure (11.79 ± 3.62 against 52.43 ± 3.01 for controls) This study will be refined by analyzing the methylation of specific regions of the genome, because it represent the sequences of genes involved in major physiological functions and that may be subject to variations in the methylation of the

  18. Military use of depleted uranium assessment of prolonged population exposure

    CERN Document Server

    Giannardi, C

    2001-01-01

    This work is an exposure assessment for a population living in an area contaminated by use of depleted uranium (DU) weapons. RESRAD 5.91 code is used to evaluate the average effective dose delivered from 1, 10, 20 cm depths of contaminated soil, in a residential farmer scenario. Critical pathway and group are identified in soil inhalation or ingestion and children playing with the soil, respectively. From available information on DU released on targeted sites, both critical and average exposure can leave to toxicological hazards; annual dose limit for population can be exceeded on short-term period (years) for soil inhalation. As a consequence, in targeted sites cleaning up must be planned on the basis of measured concentration, when available, while special cautions have to be adopted altogether to reduce unaware exposures, taking into account the amount of the avertable dose.

  19. Military use of depleted uranium: assessment of prolonged population exposure

    International Nuclear Information System (INIS)

    This work is an exposure assessment for a population living in an area contaminated by the use of depleted uranium (DU) weapons. RESRAD 5.91 code was used to evaluate the average effective dose at depths of 1, 10, 20 cm of contaminated soil, in a residential farming scenario. Critical pathways and groups are identified in soil inhalation and ingestion; critical group is identified in children playing with the soil. From the available information on DU released at targeted sites, both critical and average exposure can produce toxicological hazards. The annual dose limit for the population can be exceeded within a few years from DU deposition for soil inhalation. As a result, clean up at targeted sites must be planned on the basis of measured concentration, when available, while special measures must be adopted anyway to reduce unaware exposures

  20. External exposure from gamma radiation in uranium mines

    International Nuclear Information System (INIS)

    Radiation doses received by workers in a high ore grade uranium mine are compared to those of other radiation workers and the need to be able to calculate the exposure rate from an ore body is indicated. The uranium-238 decay chain is presented and particular reference is made to the main gamma emitters and secular equilibrium of the members of the chain. Difficulties in dealing with a self attenuating volume source, in which scattering is important, are pointed out and traditional methods of solution are mentioned. It is shown that in the special case of an infinite ore body a simple solution may be obtained using the energy conservation principle. A straightforward method for calculating the exposure rate from an arbitrarily shaped ore body is given and corrections due to air attenuation, different soil types and possible lack of secular equilibrium are dealt with. The gamma ray spectrum from the ore is discussed with specific reference to the selection of suitable exposure monitors and the calculation of transmission through shields

  1. Leukemia Among Uranium Miners-Late Effluents of Exposure to Uranium Dust

    International Nuclear Information System (INIS)

    The paper reports recent observations among Czech uranium miners. The study includes two groups of underground miners exposed in periods 1948-63 and 1968-88. A total of 9960 workers have been followed to the end of 1999 representing 267 thousands person-years. By the end of 1999, a total of 29 cases of leukemia were observed. the standardized mortality ratio is 1.31, 90% CI: 0.88-1.88. In relation to cumulated exposure to radon progeny, no statistical association is seen (p=0.172), but the trend with duration of underground work is significant (p=0.015). These contrasting results suggest that the risk of leukemia is probably related to other components in the underground environment. On the basis of the ICRP respiratory tract and biokinetic models using extrapolation of measurements of long lived radionuclides from uranium dust and external gamma radiation in Czech uranium mines since the 1970s, annual dose to the red bone marrow were estimated in the range 10-30 mSv. About 2/3 of the total dose for jobs involving drilling is due to inhalation of uranium and its decay products with ore dust, about 1/4 is due to gamma radiation, and only 5% of the dose is from radon and its progeny. The risk coefficient (Excess relative risk per sievert) corresponding to these estimates is ERR/Sv=7.1 (90% CL: 3.6-13.9). The dose estimates are subject to a considerable uncertainty. Therefore, in the absence of more exact estimates, is its more practical to assess the risk using only duration of exposure modified according to job category. As the red bone marrow estimates for hewers are about two-fold, the modification consists in according only half of the year for job categories other than hewer. Using this approach, the ERR per year is 0.15 (90% CI:0.08-027). (Author) 9 refs

  2. UDAD, Radiation Exposure to Man at Uranium Processing Plant

    International Nuclear Information System (INIS)

    1 - Description of problem or function: The Uranium Dispersion and Dosimetry (UDAD) program provides estimates of potential radiation exposure to individuals and to the general population in the vicinity of a uranium processing facility such as a uranium mine or mill. Only transport through the air is considered. Exposure results from inhalation, external irradiation from airborne and ground- deposited activity, and ingestion of foodstuffs. Individual dose commitments, population dose commitments, and environmental dose commitments are computed. The program was developed for application to uranium mining and milling; however, it may be applied to dispersion of any other pollutant. 2 - Method of solution: The removal of radioactive particles from a contaminated area such as uranium tailings by wind action is estimated from theoretical and empirical wind-erosion equations according to the wind speed, particle size distribution, surface roughness, and other parameters. Atmospheric concentrations of radioactivity from specific sources are calculated by means of a dispersion-deposition-resuspension model. Source depletion as a result of deposition, fallout of the heavier particulates, and radioactive decay and ingrowth of radon daughters are included in a sector-averaged, Gaussian plume dispersion model. The average air concentration at any given receptor location is assumed to be constant during each annual release period, but to increase from year to year because of resuspension. Surface contamination is estimated by including buildup from deposition, ingrowth of radio- active daughters, and removal by radioactive decay, weathering, and other environmental processes. Deposition velocity is estimated on the basis of particle size, density, and physical and chemical environmental conditions which influence the behavior of the smaller particles. Calculation of the inhalation dose to an individual is based on the ICRP Task Group Lung Model (TGLM). Estimates of the dose to

  3. Study of the biological effects of uranium exposure on zebra fish (D. rerio). Impact on life stages

    International Nuclear Information System (INIS)

    This work is part of an ongoing project (ENVIRHOM) started at IRSN in 2000, which consists in studying the environmental effects of radioactive substances at chronic low level of exposure. In this general frame, our aim was two fold: (i) to identify sensitivity of different critical life stages of zebra fish (fish of fresh water frequently used for tests standards in ecotoxicology) to uranium exposure and (ii) to evaluate underlying mechanisms. Experiments were conducted with eggs, larvae and genitors exposed to uranium at environmentally relevant concentrations (from 20 to 500 μg/L) in order to study survival, hatching of eggs, growth of larvae and reproduction of genitors. Bio-markers of exposure (i.e. U bioaccumulation) and bio-markers of effects at molecular level (i.e. genotoxic effects, reproductive-toxicity) were also measured. Sensitivity of fish to uranium was dependent of the life stage of development with the early life stage being the most sensitive to U either directly or maternally exposed. It underlines the relevance of including pro-larval stages for toxicity assessments in fish. Moreover drastic effects of uranium on reproductive success and DNA damages in the germ cells foretell a strong impact on the population for low concentration of exposure (20 μg/L). As it is increasingly recognized that population-level effects of toxic substances are more relevant in terms of ecological risk assessment, this study points out the need to include different life stages of organisms in eco-toxicological studies, especially the sensitive early stages. Moreover, it appears, through the comparative study of the radiological effects or by another isotope of the uranium of stronger radioactivity (233U or by an irradiation with 137Cs), that the effects of the uranium are due to its chemo-toxicity. (author)

  4. Estimating the lung burden from exposure to aerosols of depleted uranium

    International Nuclear Information System (INIS)

    Following exposure to aerosols of depleted uranium (DU), biological samples show the presence of a synthetic mixture of natural uranium and DU. By partitioning the uranium in the 24-h urine sample along the isotopic fractions of natural uranium and DU, one can study the kinetics of these subpopulations independently. A linear model is developed to estimate the lung burden of DU from measurements of DU in 24-h urine samples, years after inhalational exposure to aerosols of DU. This model takes into account the intracellular dissolution of the retained particles and the precipitation of a significant fraction of the dissolved DU as insoluble uranyl phosphates. (authors)

  5. Epidemiological study of workers at risk of internal exposure to uranium

    International Nuclear Information System (INIS)

    This work is a pilot-study among nuclear fuel cycle workers potentially exposed to alpha radiation. Internal exposure from inhalation of uranium compounds during uranium conversion and enrichment operations was estimated at the AREVA NC Pierrelatte plant. A plant specific semi-quantitative job exposure matrix (JEM) was elaborated for 2709 workers employed at this plant between 1960 and 2006. The JEM has permitted to estimate the exposure to uranium and 16 other categories of pollutants and to calculate individual cumulative exposure score. Numerous correlations were detected between uranium compounds exposure and exposure to other pollutants, such as asbestos, ceramic refractive fibers, TCE and so on. 1968-2005 mortality follow-up showed an increasing risk of mortality from pleural cancer, rectal cancer and lymphoma on the basis of national mortality rates. Analyses of association between cancer mortality and uranium exposure suggested an increase in mortality due to lung cancer among workers exposed to slowly soluble uranium compounds derived from natural and reprocessed uranium. However these results are not statistically significant and based on a small number of observed deaths. These results are concordant with previously reported results from other cohorts of workers potentially exposed to uranium. Experimental studies of biokinetic and action mechanism of slowly soluble uranium oxides bear the biological plausibility of the observed results. Influence of bias was reduced by taking into account of possible confounding including co-exposure to other carcinogenic pollutants and tobacco consumption in the study. Nevertheless, at this stage statistical power of analyses is too limited to obtain more conclusive results. This pilot study shows the interest and feasibility of an epidemiological investigation among workers at risk of internal exposure to uranium and other alpha emitters at the national level. It demonstrates the importance of exposure assessment for

  6. Induction of oxidative stress related responses in Arabidopsis thaliana following uranium exposure

    OpenAIRE

    Vanhoudt, Nathalie; Vandenhove, H.; Opdenakker, Kelly; Remans, Tony; Smeets, Karen; MARTINEZ BELLO, Daniel; van Hees, M.; Wannijn, J.; Vangronsveld, Jaco; Cuypers, Ann

    2009-01-01

    The reactive oxygen species (ROS)-signaling pathway is very important in heavy metal toxicity. Induction of the antioxidative defense mechanism, comprising ROS-scavenging enzymes and metabolites, in plants after environmental uranium contamination has been insufficiently studied in the past. This study aimed to analyze oxidative stress related responses in Arabidopsis thaliana after uranium exposure. Seventeen-day-old seedlings were exposed to 0, 0.1, 1, 10 and 100 μM uranium for 3 days. Afte...

  7. Uranium bioaccumulation and biological disorders induced in zebrafish (Danio rerio) after a depleted uranium waterborne exposure

    International Nuclear Information System (INIS)

    Because of its toxicity and its ubiquity within aquatic compartments, uranium (U) represents a significant hazard to aquatic species such as fish. In a previous study, we investigated some biological responses in zebrafish either exposed to depleted or to enriched U (i.e., to different radiological activities). However, results required further experiments to better understand biological responses. Moreover, we failed to clearly demonstrate a significant relationship between biological effects and U radiological activity. We therefore chose to herein examine U bioaccumulation and induced effects in zebrafish according to a chemical dose-response approach. Results showed that U is highly bioconcentrated in fish, according to a time- and concentration-dependent model. Additionally, hepatic antioxidant defenses, red blood cells DNA integrity and brain acetylcholinesterase activity were found to be significantly altered. Generally, the higher the U concentration, the sooner and/or the greater the effect, suggesting a close relationship between accumulation and effect. - Research highlights: → Depleted U bioconcentration factor is of about 1000 in zebrafish exposed to 20 μg/L. → Hepatic antioxidant disorders are noticed as soon as the first hours of exposure. → DNA damage is induced in red blood cells after 20 d of exposure to 500 μg DU/L. → The brain cholinergic system (AChE activity) is impacted. - This study demonstrates that U is highly bioaccumulated in fish, resulting in biological disorders such as hepatic oxidative stress as well as genotoxic and neurotoxic events.

  8. Uranium bioaccumulation and biological disorders induced in zebrafish (Danio rerio) after a depleted uranium waterborne exposure

    Energy Technology Data Exchange (ETDEWEB)

    Barillet, Sabrina, E-mail: sabrina.barillet@free.f [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France); Adam-Guillermin, Christelle, E-mail: christelle.adam-guillermin@irsn.f [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France); Palluel, Olivier, E-mail: olivier.palluel@ineris.f [Ecotoxicological Risk Assessment Unit, INERIS (National Institute for Industrial Environment and Risks), Parc technologique ALATA, 60 550 Verneuil-en-Halatte (France); Porcher, Jean-Marc, E-mail: jean-marc.porcher@ineris.f [Ecotoxicological Risk Assessment Unit, INERIS (National Institute for Industrial Environment and Risks), Parc technologique ALATA, 60 550 Verneuil-en-Halatte (France); Devaux, Alain, E-mail: alain.devaux@entpe.f [Universite de Lyon, INRA, EFPA-SA, Environmental Science Laboratory (LSE), ENTPE, 69518 Vaulx en Velin cedex (France)

    2011-02-15

    Because of its toxicity and its ubiquity within aquatic compartments, uranium (U) represents a significant hazard to aquatic species such as fish. In a previous study, we investigated some biological responses in zebrafish either exposed to depleted or to enriched U (i.e., to different radiological activities). However, results required further experiments to better understand biological responses. Moreover, we failed to clearly demonstrate a significant relationship between biological effects and U radiological activity. We therefore chose to herein examine U bioaccumulation and induced effects in zebrafish according to a chemical dose-response approach. Results showed that U is highly bioconcentrated in fish, according to a time- and concentration-dependent model. Additionally, hepatic antioxidant defenses, red blood cells DNA integrity and brain acetylcholinesterase activity were found to be significantly altered. Generally, the higher the U concentration, the sooner and/or the greater the effect, suggesting a close relationship between accumulation and effect. - Research highlights: Depleted U bioconcentration factor is of about 1000 in zebrafish exposed to 20 {mu}g/L. Hepatic antioxidant disorders are noticed as soon as the first hours of exposure. DNA damage is induced in red blood cells after 20 d of exposure to 500 {mu}g DU/L. The brain cholinergic system (AChE activity) is impacted. - This study demonstrates that U is highly bioaccumulated in fish, resulting in biological disorders such as hepatic oxidative stress as well as genotoxic and neurotoxic events.

  9. Sensitivity of Trout to Chronic Acute Exposure to Selenium

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel; Nielsen, M. Gissel

    1978-01-01

    Trout were exposed to selenite (Na2SeO3) solutions of varying concentrations (0.1-100 ppm Se) for periods of up to 4 wk. A chronic exposure to 0.1 ppm Se or less is non-lethal to trout. Lethality at higher concentrations depends on the length of exposure. Trout that survive for 10 days in tap...

  10. TELOMERASE AND CHRONIC ARSENIC EXPOSURE IN HUMANS

    Science.gov (United States)

    Arsenic exposure has been associated with increased risk of skin, lung and bladder cancer in humans. The mechanisms of carcinogenesis are not well understood. Telomerase, a ribonucleoprotein containing human telomerase reverse transcriptase (hTERT), can extend telomeres of eukary...

  11. The Toxicity of Depleted Uranium

    OpenAIRE

    Wayne Briner

    2010-01-01

    Depleted uranium (DU) is an emerging environmental pollutant that is introduced into the environment primarily by military activity. While depleted uranium is less radioactive than natural uranium, it still retains all the chemical toxicity associated with the original element. In large doses the kidney is the target organ for the acute chemical toxicity of this metal, producing potentially lethal tubular necrosis. In contrast, chronic low dose exposure to depleted uranium may not produce a c...

  12. Effect of acetaminophen administration to rats chronically exposed to depleted uranium

    International Nuclear Information System (INIS)

    The extensive use of depleted uranium (DU) in both civilian and military applications results in the increase of the number of human beings exposed to this compound. We previously found that DU chronic exposure induces the expression of CYP enzymes involved in the metabolism of xenobiotics (drugs). In order to evaluate the consequences of these changes on the metabolism of a drug, rats chronically exposed to DU (40 mg/l) were treated by acetaminophen (APAP, 400 mg/kg) at the end of the 9-month contamination. Acetaminophen is considered as a safe drug within the therapeutic range but in the case of overdose or in sensitive animals, hepatotoxicity and nephrotoxicity could occur. In the present work, plasma concentration of APAP was higher in the DU group compared to the non-contaminated group. In addition, administration of APAP to the DU-exposed rats increased plasma ALT (p < 0.01) and AST (p < 0.05) more rapidly than in the control group. Nevertheless, no histological alteration of the liver was observed but renal injury characterized by incomplete proximal tubular cell necrosis was higher for the DU-exposed rats. Moreover, in the kidney, CYP2E1 gene expression, an important CYP responsible for APAP bioactivation and toxicity, is increased (p < 0.01) in the DU-exposed group compared to the control group. In the liver, CYP's activities were decreased between control and DU-exposed rats. These results could explain the worse elimination of APAP in the plasma and confirm our hypothesis of a modification of the drug metabolism following a DU chronic contamination

  13. Hair analysis as an indicator of exposure to uranium

    International Nuclear Information System (INIS)

    Medical examinations performed on four monks of a monastery in the northern Greece revealed heavy metal contamination. Hair analysis, performed by a toxicological laboratory abroad, indicated, among other, the presence of uranium. The uranium concentrations determined in a laboratory of 'Elemental Hair Analysis' indicated a uranium level that was about five times the maximum value of the reference range, which has been adopted by the measuring laboratory. After these diagnostic findings, on request of 10 monks, uranium determination in hair and urine samples was performed by means of alpha spectrometry in GAEC's laboratory. The measured uranium concentrations in hair varied from 0.15 to 2.10 mBq g-1, which correspond to 12.1 and 170 ng g-1, respectively. The uranium concentrations in urine were between 41 and 174 ng d-1. For comparison purposes, urine and non-dyed hair samples from the staff of the laboratory were analysed. Because one of the major sources of uranium intake is through drinking water, water samples were also analysed. The mean value of the uranium concentration in the two drinking water samples collected from the residence area was found to be 2.35 μg l-1. (authors)

  14. Compared biokinetic and biological studies of chronic and acute inhalations of uranium compounds in the rat; Etudes biocinetique et biologique comparees d'inhalations chroniques et aigues de composes uraniferes chez le rat

    Energy Technology Data Exchange (ETDEWEB)

    Monleau, M

    2005-12-15

    Uranium is a natural, radioactive heavy metal, widely used in the nuclear industry in various chemical and isotopic forms. Its use in the fuel cycle involves the risk of radiological exposure for the workers, mainly via the inhalation of uranium particles. According to the workplace configuration, uranium contaminations can be acute or repeated, involve various chemical forms and different levels of enrichment, as well as involving one or several components. The dosimetric concepts and models available for workers' radiological protection, as well as most of the studies of the biological effects, correspond to acute exposure situations. Moreover the processes leading to pathological effects are little known in vivo. In this context, the main question is to know whether exposures due to repeated inhalation by rats induce the element kinetics and toxicity, which may be different from those observed after an acute exposure. In this study, comparison of the experimental and theoretical biokinetics of an insoluble uranium repeatedly inhaled over three weeks shows that a chronic contamination is correctly modelled, except for bone retention, by the sum of acute, successive and independent incorporations. Moreover, the kinetics of a soluble uranium inhaled irregularly can be modified by previous repeated exposure to an insoluble uranium. In certain cases therefore, exposure to uranium could modify its biokinetics during later exposures. At a toxicological level, the study demonstrates that the uranium particles inhaled repeatedly induce behavioural disruptions and genotoxic effects resulting in various sorts of DNA damage, in several cell types and certainly depending on the quantity inhaled. Exposures involving several uraniferous components produce a synergy effect. Moreover, repeated inhalations worsen the genotoxic effects in comparison to an acute exposure. This work demonstrates the importance of not ignoring the effects of the repetition of uranium exposure

  15. Long-term ecological effects of exposure to uranium

    International Nuclear Information System (INIS)

    The consequences of releasing natural and depleted uranium to terrestrial ecosystems during development and testing of depleted uranium munitions were investigated. At Eglin Air Force Base, Florida, soil at various distances from armor plate target butts struck by depleted uranium penetrators was sampled. The upper 5 cm of soil at the target bases contained an average of 800 ppM of depleted uranium, about 30 times as much as soil at 5- to 10-cm depth, indicating some vertical movement of depleted uranium. Samples collected beyond about 20 m from the targets showed near-background natural uranium levels, about 1.3 +- 0.3 μg/g or ppM. Two explosives-testing areas at the Los Alamos Scientific Laboratory (LASL) were selected because of their use history. E-F Site soil averaged 2400 ppM of uranium in the upper 5 cm and 1600 ppM at 5-10 cm. Lower Slobovia Site soil from two subplots averaged about 2.5 and 0.6 percent of the E-F Site concentrations. Important uranium concentration differences with depth and distance from detonation points were ascribed to the different explosive tests conducted in each area. E-F Site vegetation samples contained about 320 ppM of uranium in November 1974 and about 125 ppM in June 1975. Small mammals trapped in the study areas in November contained a maximum of 210 ppM of uranium in the gastrointestinal tract contents, 24 ppM in the pelt, and 4 ppM in the remaining carcass. In June, maximum concentrations were 110, 50, and 2 ppM in similar samples and 6 ppM in lungs. These data emphasized the importance of resuspension of respirable particles in the upper few millimeters of soil as a contamination mechanism for several components of the LASL ecosystem

  16. Long-term ecological effects of exposure to uranium

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, W.C.; Miera, F.R. Jr.

    1976-03-01

    The consequences of releasing natural and depleted uranium to terrestrial ecosystems during development and testing of depleted uranium munitions were investigated. At Eglin Air Force Base, Florida, soil at various distances from armor plate target butts struck by depleted uranium penetrators was sampled. The upper 5 cm of soil at the target bases contained an average of 800 ppM of depleted uranium, about 30 times as much as soil at 5- to 10-cm depth, indicating some vertical movement of depleted uranium. Samples collected beyond about 20 m from the targets showed near-background natural uranium levels, about 1.3 +- 0.3 ..mu..g/g or ppM. Two explosives-testing areas at the Los Alamos Scientific Laboratory (LASL) were selected because of their use history. E-F Site soil averaged 2400 ppM of uranium in the upper 5 cm and 1600 ppM at 5-10 cm. Lower Slobovia Site soil from two subplots averaged about 2.5 and 0.6 percent of the E-F Site concentrations. Important uranium concentration differences with depth and distance from detonation points were ascribed to the different explosive tests conducted in each area. E-F Site vegetation samples contained about 320 ppM of uranium in November 1974 and about 125 ppM in June 1975. Small mammals trapped in the study areas in November contained a maximum of 210 ppM of uranium in the gastrointestinal tract contents, 24 ppM in the pelt, and 4 ppM in the remaining carcass. In June, maximum concentrations were 110, 50, and 2 ppM in similar samples and 6 ppM in lungs. These data emphasized the importance of resuspension of respirable particles in the upper few millimeters of soil as a contamination mechanism for several components of the LASL ecosystem.

  17. Comments upon human exposure to depleted uranium during and after the Gulf and Balkans conflicts

    International Nuclear Information System (INIS)

    The Royal Society report contains a number of comments and suggestions which are questionable or are not acceptable. Because of the total failure to obtain minimal environmental and clinical data at the time of the conflicts, retrospective, abstract epidemiological studies are unlikely to be of any value, indeed the confounding issues are so numerous that any success cannot be expected. Some individuals during the Gulf conflict seem to have been exposed to a cocktail of drugs and possibly other biological agents for which information is sparse with respect to amounts, routes of exposure and acute versus chronic symptoms. Spratt does not examine the matter of 'hot particles' in sufficient depth; for purposes of the report it is irrelevant whether or not hot particles are of any particular concern, simply that they have been poorly studied and data are lacking upon which a judgement can be made. Hamilton presented a rare description for the in situ distribution of uranium in human bone for chronic nonoccupationally exposed individuals. The uranium exhibited a distribution which reflected uptake of uranium on endosteal surfaces, especially of trabecular bone. The general labelling of bone apatite was not observed, hence the chronic diffusion of uranium deposited on endosteal surfaces does not appear to penetrate the inorganic bone tissues. For labelled Haversian systems in long bone, the physical geometry of deposition as viewed by autoradiographic techniques has an appearance of hot particle configurations. Recent discoveries that stem cells are associated with such surfaces raise the question of their susceptibility to both inorganic uranium and any associated ionisation radiation which is related to point source depositions The actual cell or cell surfaces where the uranium is taken up are unknown. The same situation in principle applies to thoracic lymph nodes, albeit their susceptibility and biological purpose renders them of less concern. The comment that it is

  18. Analytical developments for the speciation of uranium in zebra fish (Danio rerio) gills after exposure

    International Nuclear Information System (INIS)

    The objective of this thesis is to study the cellular compartmentalization and the chelation of uranium (U) by cytosolic proteins of gill cells of the zebra fish (Danio rerio, model specie in aquatic toxicology) under different direct exposure conditions (chronic vs. acute, 20 and 250 μg.L-1). This study required the development of hyphenated techniques (SEC, IEF off-gel, RP-UHPLC for the separation, ICP-SFMS, ESI-FTMS/MS for the detection) with the main challenges of maintaining the non-covalent U-biomolecule interactions and enhancing sensitivity for the analysis of environmentally relevant samples. After extraction, 24% to 32% of the total U detected in the gills were present in the cytosolic fraction, in which the U distribution on the biomolecules (as a function of their MW and pI) varied depending on the exposure level. Finally, U target biomolecules mapping allowed us (i) to highlight a particular affinity of U for acidic and/or P-containing proteins and (ii) to identify 24 protein candidates for U binding. (author)

  19. Cross-sectional study of uranium mine workers to develop predictive equations for lung functions with reference to chronic obstructive pulmonary disease

    International Nuclear Information System (INIS)

    As the first part of a prospective epidemiological study of the lung function and dust exposure of workers at the Roessing Uranium Mine in SWA/Namibia, various measurements of lung function of 1 407 workers were carried out. This was necessary in order to follow up any chronic obstructive pulmonary disease that might develop. The opportunity was used to test existing prediction formulae and to develop formulae for normal values for workers at the Roessing mine. 94 refs., 36 figs., 14 tabs

  20. Impact of chronic and acute pesticide exposures on periphyton communities

    International Nuclear Information System (INIS)

    Aquatic ecosystems face variable exposure to pesticides, especially during floodings which are associated with short bursts of high contaminant concentrations that influence biological systems. A study was undertaken to highlight the impact of the herbicide diuron applied in mixture with the fungicide tebuconazole on natural periphyton during flooding events. Periphyton were grown in two series of two lotic outdoor mesocosms: one series was non-contaminated while the other was exposed to chronic contamination. After 4 weeks, one channel of each series was exposed to three successive pulses, with each pulse followed by one week of recovery. Impacts on periphyton were assessed by using Denaturing Gel Gradient Electrophoresis to characterize eukaryotic community structure. At a functional scale, photosynthetic efficiency was quantified during each pulse, and the induced tolerance to diuron was estimated by performing short-term inhibition tests based on photosynthetic efficiency. Moreover, pesticide concentrations in the water column and periphyton matrix were measured. Diuron was adsorbed in the periphyton during each pulse and desorbed 13 h after pulse end. The different pulses affected the eukaryotic community structures of the control biofilms, but not of the chronically exposed ones. During the first pulse, photosynthetic efficiency was correlated with pesticide concentration in the water phase, and there was no difference between periphyton from chronically contaminated channels and control channels. However, during the second and third pulses, the photosynthetic efficiency of periphyton chronically exposed to pesticides appeared to be less impacted by the acute pulsed exposure of pesticide. These changes were consistent with the acquisition of induced tolerance to diuron since only after the third pulse that periphyton from chronic channel became tolerant to diuron. Our experimental study indicates that the effects of pulsed acute exposures to pesticides on

  1. The brain is a target organ after acute exposure to depleted uranium

    International Nuclear Information System (INIS)

    The health effects of depleted uranium (DU) are mainly caused by its chemical toxicity. Although the kidneys are the main target organs for uranium toxicity, uranium can also reach the brain. In this paper, the central effects of acute exposure to DU were studied in relation to health parameters and the sleep-wake cycle of adult rats. Animals were injected intraperitoneally with 144 ± 10 μg DU kg-1 as nitrate. Three days after injection, the amounts of uranium in the kidneys represented 2.6 μg of DU g-1 of tissue, considered as a sub-nephrotoxic dosage. The central effect of uranium could be seen through a decrease in food intake as early as the first day after exposure and shorter paradoxical sleep 3 days after acute DU exposure (-18% of controls). With a lower dosage of DU (70 ± 8 μg DU kg-1), no significant effect was observed on the sleep-wake cycle. The present study intends to illustrate the fact that the brain is a target organ, as are the kidneys, after acute exposure to a moderate dosage of DU. The mechanisms by which uranium causes these early neurophysiological perturbations shall be discussed

  2. CHRONIC DEVELOPMENTAL LEAD EXPOSURE REDUCES NEUROGENESIS IN ADULT HIPPOCAMPUS.

    Science.gov (United States)

    CHRONIC DEVELOPMENTAL LEAD EXPOSURE REDUCES NEUROGENESIS IN ADULT HIPPOCAMPUS. ME Gilbert1, ME Kelly2, S. Salant3, T Shafer1, J Goodman3 1Neurotoxicology Div, US EPA, RTP, NC, 27711, 2Children's Hospital, Philadelphia, PA, 19104, 3Helen Hayes Hospital, Haverstraw, NY, 10993. ...

  3. Occupational diseases in uranium and ore miners in connection with radiation exposure in the Czech Republic

    International Nuclear Information System (INIS)

    Dozens cases of diseases are submitted to judgement as occupational diseases every year in the Czech Republic. Patients or attending physicians suggest that these cases are caused by occupational ionizing radiation. Only a part of these cases is qualified as occupational disease. The term 'occupational disease' is rather a juridical term which underlies the right to financial compensation. The causal association with exposure to ionizing radiation cannot be indisputably verified by expert medical opinion. Most diseases, which are proposed as occupational disease, are malignant tumors of the lungs. Total majority of judged cases are lung cancers from radioactive agents. In 2002, a total of 33 cases of lung cancer in former uranium or ore miners have been acknowledged as occupational diseases. The decision about occupational disease is derived from probabilistic approach based on estimation of probability of causation of irradiation on disease origin (methodical guideline No. 15 of Ministry of Health Bulletin, part 9, 1998). The presented paper gives a general information about all judged causes of occupational diseases in former uranium and ore miners in the Czech Republic in 2002. A total of 72 cases were submitted to judgement of conditions of disease origin to the National Radiation Protection Institute in 2002. 67 cases were lung cancers, 1 case was chronic myeloid leukemia, acute myeloid leukemia, basaliom, cancer of larynx and cancer of nasal septum. The probability of causation was assessed as prevailing in 32 cases of lung cancer, borderline in 5 cases and low in other 30 cases of lung cancer. The probability of causation was prevailing in both cases of myeloid leukemia. (author)

  4. Uranium

    International Nuclear Information System (INIS)

    The article includes a historical preface about uranium, discovery of portability of sequential fission of uranium, uranium existence, basic raw materials, secondary raw materials, uranium's physical and chemical properties, uranium extraction, nuclear fuel cycle, logistics and estimation of the amount of uranium reserves, producing countries of concentrated uranium oxides and percentage of the world's total production, civilian and military uses of uranium. The use of depleted uranium in the Gulf War, the Balkans and Iraq has caused political and environmental effects which are complex, raising problems and questions about the effects that nuclear compounds left on human health and environment.

  5. Does uranium exposure induce genotoxicity in the teleostean Danio rerio? First experimental results

    OpenAIRE

    Barillet, S.; Buet, A.; Adam, C.; Devaux, Alain

    2005-01-01

    Zebrafish were exposed to different concentrations of waterborne uranium (0, 20, 100 and 500 $\\mu$g U.L-1) and were sacrificed for blood sampling after different exposure periods (12h, 36h, 72h, 5, 10 and 20 days) in order to assess DNA integrity in erythrocytes, using the comet assay and flow cytometry. Concurrently, uranium bioaccumulation was studied in the remaining tissues to understand the potential genotoxic biomarker responses. Both genotoxic assays revealed significant effect of wate...

  6. Joint analysis of French and Czech uranium miners: lung cancer risk at low radon exposure rates and modifying effects of time since exposure and age at exposure

    International Nuclear Information System (INIS)

    The present analysis was conducted in the frame of European project 'Quantification of lung cancer risk after low radon exposure and low exposure rate: synthesis from epidemiologic and experimental data'. The overall goal of the project related to uranium miners was the evaluation of lung cancer dose-response relationship and of dose rate effects among European uranium miners exposed to low doses and low dose rates of radon decay products. In addition, modifying factors like attained age, age at exposure and time since exposure were investigated. The joint analysis of French and Czech uranium miners was conducted mainly in order to increase the statistical power and to allow a more detailed description of the variation of dose-response relationship in time. (N.C.)

  7. Evaluation of health effects in Sequoyah Fuels Corporation workers from accidental exposure to uranium hexafluoride

    International Nuclear Information System (INIS)

    Urine bioassay measurements for uranium and medical laboratory results were studied to determine whether there were any health effects from uranium intake among a group of 31 workers exposed to uranium hexafluoride (UF6) and hydrolysis products following the accidental rupture of a 14-ton shipping cylinder in early 1986 at the Sequoyah Fuels Corporation uranium conversion facility in Gore, Oklahoma. Physiological indicators studied to detect kidney tissue damage included tests for urinary protein, casts and cells, blood, specific gravity, and urine pH, blood urea nitrogen, and blood creatinine. We concluded after reviewing two years of follow-up medical data that none of the 31 workers sustained any observable health effects from exposure to uranium. The early excretion of uranium in urine showed more rapid systemic uptake of uranium from the lung than is assumed using the International Commission on Radiological Protection (ICRP) Publication 30 and Publication 54 models. The urinary excretion data from these workers were used to develop an improved systemic recycling model for inhaled soluble uranium. We estimated initial intakes, clearance rates, kidney burdens, and resulting radiation doses to lungs, kidneys, and bone surfaces. 38 refs., 10 figs., 7 tabs

  8. US Transuranium and Uranium Registries case study on accidental exposure to uranium hexafluoride

    International Nuclear Information System (INIS)

    The United States Transuranium and Uranium Registries’ (USTUR) whole-body donor (Case 1031) was exposed to an acute inhalation of uranium hexafluoride (UF6) produced from an explosion at a uranium processing plant 65 years prior to his death. The USTUR measurements of tissue samples collected at the autopsy indicated long-term retention of inhaled slightly enriched uranium material (0.85% 235U) in the deep lungs and thoracic lymph nodes. In the present study, the authors combined the tissue measurement results with historical bioassay data, and analysed them with International Commission on Radiological Protection (ICRP) respiratory tract models and the ICRP Publication 69 systemic model for uranium using maximum likelihood and Bayesian statistical methods. The purpose of the analysis was to estimate intakes and model parameter values that best describe the data, and evaluate their effect on dose assessment. The maximum likelihood analysis, which used the ICRP Publication 66 human respiratory tract model, resulted in a point estimate of 79 mg of uranium for the occupational intake composed of 86% soluble, type F material and 14% insoluble, type S material. For the Bayesian approach, the authors applied the Markov Chain Monte Carlo method, but this time used the revised human respiratory tract model, which is currently being used by ICRP to calculate new dose coefficients for workers. The Bayesian analysis estimated that the mean uranium intake was 160 mg, and calculated the case-specific lung dissolution parameters with their associated uncertainties. The parameters were consistent with the inhaled uranium material being predominantly soluble with a small but significant insoluble component. The 95% posterior range of the rapid dissolution fraction (the fraction of deposited material that is absorbed to blood rapidly) was 0.12 to 0.91 with a median of 0.37. The remaining fraction was absorbed slowly, with a 95% range of 0.000 22 d−1 to 0.000 36

  9. US Transuranium and Uranium Registries case study on accidental exposure to uranium hexafluoride.

    Science.gov (United States)

    Avtandilashvili, Maia; Puncher, Matthew; McComish, Stacey L; Tolmachev, Sergei Y

    2015-03-01

    The United States Transuranium and Uranium Registries' (USTUR) whole-body donor (Case 1031) was exposed to an acute inhalation of uranium hexafluoride (UF6) produced from an explosion at a uranium processing plant 65 years prior to his death. The USTUR measurements of tissue samples collected at the autopsy indicated long-term retention of inhaled slightly enriched uranium material (0.85% (235)U) in the deep lungs and thoracic lymph nodes. In the present study, the authors combined the tissue measurement results with historical bioassay data, and analysed them with International Commission on Radiological Protection (ICRP) respiratory tract models and the ICRP Publication 69 systemic model for uranium using maximum likelihood and Bayesian statistical methods. The purpose of the analysis was to estimate intakes and model parameter values that best describe the data, and evaluate their effect on dose assessment. The maximum likelihood analysis, which used the ICRP Publication 66 human respiratory tract model, resulted in a point estimate of 79 mg of uranium for the occupational intake composed of 86% soluble, type F material and 14% insoluble, type S material. For the Bayesian approach, the authors applied the Markov Chain Monte Carlo method, but this time used the revised human respiratory tract model, which is currently being used by ICRP to calculate new dose coefficients for workers. The Bayesian analysis estimated that the mean uranium intake was 160 mg, and calculated the case-specific lung dissolution parameters with their associated uncertainties. The parameters were consistent with the inhaled uranium material being predominantly soluble with a small but significant insoluble component. The 95% posterior range of the rapid dissolution fraction (the fraction of deposited material that is absorbed to blood rapidly) was 0.12 to 0.91 with a median of 0.37. The remaining fraction was absorbed slowly, with a 95% range of 0.000 22 d(-1) to 0.000 36

  10. Radiation exposure and attributable cancer risk in former miners of the WISMUT uranium mining company

    International Nuclear Information System (INIS)

    Since 1990 about 5000 cases of lung cancer and nearly 1000 cases of extrapulmonary cancers among earlier workers in the WISMUT uranium facilities in East Germany have been submitted to the responsible German associations for the acknowledgement of occupational diseases and the compensation of workers. In the paper the general methods and models for the retrospective estimation of the radiation exposure of these workers and for the evaluation of the attributable cancer risk are shortly outlined. With respect to lung cancer among underground uranium miners the inhalation of the short-lived radon progenies is by far the most important exposure component. For the attributable risk of extrapulmonary cancers, however, in addition the inhalation of natural uranium included in ore dust particles has to be taken into account. The analysis indicates that under certain exposure conditions also leukemia, bone and liver cancer, as well as cancers in the oral cavity and larynx may be of some importance. (orig.)

  11. Anxiogenic-like effects of chronic nicotine exposure in zebrafish.

    Science.gov (United States)

    Stewart, Adam Michael; Grossman, Leah; Collier, Adam D; Echevarria, David J; Kalueff, Allan V

    2015-12-01

    Nicotine is one of the most widely used and abused legal drugs. Although its pharmacological profile has been extensively investigated in humans and rodents, nicotine CNS action remains poorly understood. The importance of finding evolutionarily conserved signaling pathways, and the need to apply high-throughput in vivo screens for CNS drug discovery, necessitate novel efficient experimental models for nicotine research. Zebrafish (Danio rerio) are rapidly emerging as an excellent organism for studying drug abuse, neuropharmacology and toxicology and have recently been applied to testing nicotine. Anxiolytic, rewarding and memory-modulating effects of acute nicotine treatment in zebrafish are consistently reported in the literature. However, while nicotine abuse is more relevant to long-term exposure models, little is known about chronic effects of nicotine on zebrafish behavior. In the present study, chronic 4-day exposure to 1-2mg/L nicotine mildly increased adult zebrafish shoaling but did not alter baseline cortisol levels. We also found that chronic exposure to nicotine evokes robust anxiogenic behavioral responses in zebrafish tested in the novel tank test paradigm. Generally paralleling clinical and rodent data on anxiogenic effects of chronic nicotine, our study supports the developing utility of zebrafish for nicotine research. PMID:25643654

  12. Hepatotoxic potential of combined toluene-chronic ethanol exposure

    Energy Technology Data Exchange (ETDEWEB)

    Howell, S.R.; Christian, J.E.; Isom, G.E.

    1986-05-01

    The hepatoxic properties of concurrent chronic oral ethanol ingestion and acute toluene inhalation were evaluated. Male rats were maintained on ethanol-containing or control liquid diets for 29 days. Animals of each group were subjected to five 20-min exposures to 10 000 ppm toluene with 30 min of room air inhalation between exposures on days 22, 24, 26, and 28 of liquid diet feeding. Some of the ethanol-fed animals were withdrawn from ethanol 14 h before exposure. Ethanol-withdrawn animals displayed an increased sensitivity to the narcotic action of toluene. Animals were sacrificed and assays performed on day 29. Stress markers (plasma corticosterone, free fatty acid, and glucose) were not affected by treatments. A modest elevation in plasma aspartate amino-transferase occurred in non-withdrawn animals receiving both ethanol and toluene. Ethanol-toluene exposure increased both relative liver weight and liver triglycerides. Toluene antagonized the hypertriglyceridemia associated with chronic ethanol ingestion. This study indicates that combined ethanol and toluene exposure has minor potential to induce acute liver injury, but results in altered deposition of hepatic triglycerides.

  13. Sensitivity of Trout to Chronic Acute Exposure to Selenium

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel; Nielsen, M. Gissel

    1978-01-01

    Trout were exposed to selenite (Na2SeO3) solutions of varying concentrations (0.1-100 ppm Se) for periods of up to 4 wk. A chronic exposure to 0.1 ppm Se or less is non-lethal to trout. Lethality at higher concentrations depends on the length of exposure. Trout that survive for 10 days in tap......-water after contamination will not die as a result of Se toxicity and can safely be used for human consumption....

  14. Population Exposure to Depleted Uranium in the Han Pijesak Region

    OpenAIRE

    Zora S. Žunić; Rodoljub Simović; Zoran Ćurguz; Olivera Čuknić; Jerzy Mietelski; Predrag Ujić; Igor Čeliković; Predrag Kolarž; Branko Predojević

    2011-01-01

    In September 1995 the Han Pijesak area of Republic of Srpska was heavily attacked by Depleted Uranium (DU) ammunition. In this area, from 2003 to 2004, during one year, the components of natural ionizing radiation sources like radon, thoron, and gamma radiation were measured. In addition, during the same period, the samples of soil, moss, and lichen were collected in order to identify the content of technologically enhanced natural radionuclides in them and particularly their isotopic ratios,...

  15. Does chronic exposure to mobile phones affect cognition?

    OpenAIRE

    Mohan, Mamta; Khaliq, Farah; Panwar, Aprajita; Vaney, Neelam

    2016-01-01

    Mobile phones form an integral part of our modern lifestyle. Following the drastic rise in mobile phone use in recent years, it has become important to study its potential public health impact. Amongst the various mobile phone health hazards, the most alarming is the possible effect on the brain. The aim of the present study was to explore whether chronic exposure to mobile phones affects cognition. Ninety subjects aged 17–25 years with normal hearing were recruited for the study and divided ...

  16. Acute and chronic toxicity of uranium compounds to Ceriodaphnia-Daphnia dubia

    International Nuclear Information System (INIS)

    A study to determine the acute and chronic toxicity of uranyl nitrate, hydrogen uranyl phosphate, and uranium dioxide to the organism Ceriodaphnia dubia was conducted. The toxicity tests were conducted by two independent environmental consulting laboratories. Part of the emphasis for this determination was based on concerns expressed by SCDHEC, which was concerned that a safety factor of 100 must be applied to the previous 1986 acute toxicity result of 0.22 mg/L for Daphnia pulex, This would have resulted in the LETF release limits being based on an instream concentration of 0.0022 mg/L uranium. The NPDES Permit renewal application to SCDHEC utilized the results of this study and recommended that the LETF release limit for uranium be based an instream concentration of 0.004 mg/L uranium. This is based on the fact that the uranium releases from the M-Area LETF will be in the hydrogen uranyl phosphate form, or a uranyl phosphate complex at the pH (6--10) of the Liquid Effluent Treatment Facility effluent stream, and at the pH of the receiving stream (5.5 to 7.0). Based on the chronic toxicity of hydrogen uranyl phosphate, a lower uranium concentration limit for the Liquid Effluent Treatment Facility outfall vs. the existing NPDES permit was recommended: The current NPDES permit ''Guideline'' for uranium at outfall M-004 is 0.500 mg/L average and 1.0 mg/L maximum, at a design flowrate of 60 gpm. It was recommended that the uranium concentration at the M-004 outfall be reduced to 0.28 mg/L average, and 0.56 mg/L, maximum, and to reduce the design flowrate to 30 gpm. The 0.28 mg/L concentration will provide an instream concentration of 0.004 mg/L uranium. The 0.28 mg/L concentration at M-004 is based on the combined flows from A-014, A-015, and A-011 outfalls (since 1985) of 1840 gpm (2.65 MGD) and was the flow rate which was utilized in the 1988 NPDES permit renewal application

  17. Epidemiology of Czech and French Uranium Miners; Lung Cancer Risk Linked to low Radon Exposure

    International Nuclear Information System (INIS)

    Full text: Comprehensive results from miners cohorts have demonstrated a clear association between lung cancer risk and radon exposure cumulated during occupational life. However a large proportion of these miners had cumulated high radon exposure during a short period. The French and Czech cohorts of uranium miners allow to analyse the potential risk linked to low radon exposures protracted over long duration. Furthermore, the study will allow to consider the modifying effects of other factors present in the mining atmosphere. The present analysis is based on 5098 miners employed in French uranium mines for at least one year since 1945, and followed up to 1994. A total of 5002 Czech miners employed since 1952 have been followed up to 1995. Mean cumulative exposures are 36 and 57 WLM among French and Czech miners, respectively, protracted in average over 11 and 10 years. A significant excess of lung cancer deaths is observed in both cohorts. A linear association of this risk with cumulative exposure to radon was confirmed. he purpose of the joint analysis is to study the influence of low annual exposures (exposure rate effect). According to these analyses, the occupational exposure gives the opportunity to evaluate lung cancer risk for annual exposures to radon in the range of 2 WLM or less, the levels that are comparable to exposures of about 400-500Bq/m3 in dwellings. (author)

  18. Correlation between airborne U exposure and U urinalysis results at Bear Creek Uranium

    International Nuclear Information System (INIS)

    Inhalation exposure history and U urinalysis data collected at Union Pacific Resources Company's Bear Creek Uranium milling operation, located in the Powder River Basin area of Wyoming, were studied to determine if a correlation could be made between airborne U exposure and U urinalysis results. It was observed from these data that U urinalysis results correlate with airborne U exposure levels when averaged over a period of time. The urinary U excretion rate, empirically derived from these data, was 1.8 X 10(-1) micrograms U in urine d-1 per micrograms U inhaled d-1 for samples collected after 2.9 d of no exposure

  19. Induction of oxidative stress related responses in Arabidopsis thaliana after uranium exposure

    International Nuclear Information System (INIS)

    Uranium contamination in the environment has resulted from releases linked with nuclear fuel cycle activities and from industries extracting and processing materials containing naturally occurring radionuclides (for example phosphate industry). Uranium toxicity effects are predominantly studied on man and animal species, but little information is available for plants. If phytomanagement of uranium contaminated soils is considered, biological effects on the vegetation have to be investigated. Information on the contamination impact can also be used for risk assessment and derivation of clean-up standards. Plants can experience oxidative stress when they are exposed to environmental stress situations (for example exposure to heavy metals). Reactive oxygen species (ROS) are produced in both stressed and unstressed cells potentially leading to cellular damage. Consequently, plants have developed an antioxidative defence system comprising ROS-scavenging enzymes (e.g. SOD (superoxide dismutase), CAT (catalase) and metabolites (e.g. ascorbate, glutathione). Previous results showed that uranium exposure can cause an imbalance between the oxidative and antioxidative capacities of the plant cells. The present study aimed to analyse biological effects induced in Arabidopsis thaliana after bioaccumulation of uranium and to define possible dose-effect relationships. Subtle effects on the antioxidative defence system (enzymes, metabolites viewed as early responses for individual disturbances (growth, nutrient profile) were analysed

  20. The utility of in vitro solubility testing in assessment of uranium exposure

    International Nuclear Information System (INIS)

    Assessment of accidental exposures in the uranium industry requires estimation of retention and excretion rates using bioassay measurements. This task is difficult if the solubility of the inhaled uranium compound is unknown. In our research, Beagle dogs were exposed to aerosols of commercial uranium milling products containing either pure ammonium diuranate (ADU) or U308. Dogs were exposed to ADU aerosols to achieve a median retained body burden of 0.058 mg U per kg body weight, or to U308 aerosols to achieve a median retained body burden of 0.28 mg U per kg. A biokinetic model was applied to simulate retention and excretion of the two forms of uranium in vivo. Comparison of published in vitro dissolution data and modelling results with information from accidental human exposures showed that in vitro dissolution studies are necessary to characterise the differential solubilities of uranium compounds, and indicate the potential for kidney toxicity. Because variability in pulmonary clearance and urinary excretion rates is high among individual people, in vitro dissolution results are only marginally useful for estimating urinary excretion rates. (author)

  1. In vivo effects of a chronic contamination by uranium or cesium 137 on the pharmaceutical metabolism, of the vitamin D and cholesterol

    International Nuclear Information System (INIS)

    In conclusion, an animal model, miming the chronic contamination of the populations exposed to the uranium, was used for the first time to show that the chronic ingestion of a weak dose of depleted uranium can affect the level of active vitamin D without modifying the mineral homeostasis. This study shows that this radionuclide can lead molecular modifications of the CYPs and the nuclear receivers involved in the metabolism of the vitamin D not only at the level of the liver and kidney but also at the level of the independent metabolism in the brain. The deficiency in vitamin D can provoke osseous diseases such as the rickets at the child and the osteomalacia at the adult. The three categories of population the most exposed to this deficiency are the infants, the pregnant women and the old persons. Strong prevalence of the vitamin D deficiency associated with a chronic exposure to uranium could lead to osseous disorders. To verify this hypothesis, it will be necessary secondly to realize this study on individuals animal models predisposed to the rickets or to the osteomalacia. (N.C.)

  2. Uranium

    International Nuclear Information System (INIS)

    With the worldwide revival of nuclear energy comes the question of uranium reserves. For more than 20 years, nuclear energy has been neglected and uranium prospecting has been practically abandoned. Therefore, present day production covers only 70% of needs and stocks are decreasing. Production is to double by 2030 which represents a huge industrial challenge. The FBR-type reactors technology, which allows to consume the whole uranium content of the fuel, is developing in several countries and will ensure the long-term development of nuclear fission. However, the implementation of these reactors (the generation 4) will be progressive during the second half of the 21. century. For this reason an active search for uranium ores will be necessary during the whole 21. century to ensure the fueling of light water reactors which are huge uranium consumers. This dossier covers all the aspects of natural uranium production: mineralogy, geochemistry, types of deposits, world distribution of deposits with a particular attention given to French deposits, the exploitation of which is abandoned today. Finally, exploitation, ore processing and the economical aspects are presented. Contents: 1 - the uranium element and its minerals: from uranium discovery to its industrial utilization, the main uranium minerals (minerals with tetravalent uranium, minerals with hexavalent uranium); 2 - uranium in the Earth's crust and its geochemical properties: distribution (in sedimentary rocks, in magmatic rocks, in metamorphic rocks, in soils and vegetation), geochemistry (uranium solubility and valence in magmas, uranium speciation in aqueous solution, solubility of the main uranium minerals in aqueous solution, uranium mobilization and precipitation); 3 - geology of the main types of uranium deposits: economical criteria for a deposit, structural diversity of deposits, classification, world distribution of deposits, distribution of deposits with time, superficial deposits, uranium

  3. Uranium hexafluoride public risk

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, D.R.; Hui, T.E.; Yurconic, M.; Johnson, J.R.

    1994-08-01

    The limiting value for uranium toxicity in a human being should be based on the concentration of uranium (U) in the kidneys. The threshold for nephrotoxicity appears to lie very near 3 {mu}g U per gram kidney tissue. There does not appear to be strong scientific support for any other improved estimate, either higher or lower than this, of the threshold for uranium nephrotoxicity in a human being. The value 3 {mu}g U per gram kidney is the concentration that results from a single intake of about 30 mg soluble uranium by inhalation (assuming the metabolism of a standard person). The concentration of uranium continues to increase in the kidneys after long-term, continuous (or chronic) exposure. After chronic intakes of soluble uranium by workers at the rate of 10 mg U per week, the concentration of uranium in the kidneys approaches and may even exceed the nephrotoxic limit of 3 {mu}g U per gram kidney tissue. Precise values of the kidney concentration depend on the biokinetic model and model parameters assumed for such a calculation. Since it is possible for the concentration of uranium in the kidneys to exceed 3 {mu}g per gram tissue at an intake rate of 10 mg U per week over long periods of time, we believe that the kidneys are protected from injury when intakes of soluble uranium at the rate of 10 mg U per week do not continue for more than two consecutive weeks. For long-term, continuous occupational exposure to low-level, soluble uranium, we recommend a reduced weekly intake limit of 5 mg uranium to prevent nephrotoxicity in workers. Our analysis shows that the nephrotoxic limit of 3 {mu}g U per gram kidney tissues is not exceeded after long-term, continuous uranium intake at the intake rate of 5 mg soluble uranium per week.

  4. Uranium

    International Nuclear Information System (INIS)

    The author discusses the contribution made by various energy sources in the production of electricity. Estimates are made of the future nuclear contribution, the future demand for uranium and future sales of Australian uranium. Nuclear power growth in the United States, Japan and Western Europe is discussed. The present status of the six major Australian uranium deposits (Ranger, Jabiluka, Nabarlek, Koongarra, Yeelerrie and Beverley) is given. Australian legislation relevant to the uranium mining industry is also outlined

  5. Uranium

    International Nuclear Information System (INIS)

    The development, prospecting, research, processing and marketing of South Africa's uranium industry and the national policies surrounding this industry form the headlines of this work. The geology of South Africa's uranium occurences and their positions, the processes used in the extraction of South Africa's uranium and the utilisation of uranium for power production as represented by the Koeberg nuclear power station near Cape Town are included in this publication

  6. Uranium

    International Nuclear Information System (INIS)

    A discussion is given of uranium as an energy source in The Australian economy. Figures and predictions are presented on the world supply-demand position and also figures are given on the added value that can be achieved by the processing of uranium. Conclusions are drawn about Australia's future policy with regard to uranium (R.L.)

  7. Uranium

    International Nuclear Information System (INIS)

    The geological setting of uranium resources in the world can be divided in two basic categories of resources and are defined as reasonably assured resources, estimated additional resources and speculative resources. Tables are given to illustrate these definitions. The increasing world production of uranium despite the cutback in the nuclear industry and the uranium requirements of the future concluded these lecture notes

  8. Assessment of uranium exposure in a community near former uranium mining and milling

    International Nuclear Information System (INIS)

    The northern region of Karnes County, Texas has been the site of extensive mining and milling of uranium-238 (238U) for over 30 years. Measurements of 238U were conducted to test the hypothesis that past mining/milling efforts have increased the environmental burden of 238U in local residential areas. 238U concentrations and lead isotope ratios were measured by ICP-MS in soil, plant tissues, household furnace filters, carpet dusts and drinking water. Soil samples (n=75) were collected from the yards of previously studied homes at the surface and 30 cm subsurface. From each home carpet vacuums, filter entrapments and dust swabs were collected (total n=15) as were water wells samples when available (n=7). A site located over 8 miles south of the study area and with no history of mining or milling facilities was found to be consistently and statistically (p238U contamination in the study area from high grade imported ore. The water sample near the largest mining/milling operation compared to the control site, indicating leaching into the groundwater. Analysis of dust samples indicates indoor contamination as 238U was as much as 10X higher in homes from the mining/milling areas compared to the control region. Data thus far indicates that uranium contamination from mining/milling activities is likely to be the cause of the previously documented biological effects and suggests increased health risks for these residents

  9. Chronic escalating cocaine exposure, abstinence/withdrawal, and chronic re-exposure: Effects on striatal dopamine and opioid systems in C57BL/6J mice

    OpenAIRE

    Yong ZHANG; Schlussman, Stefan D; Rabkin, Jacqui; Butelman, Eduardo R.; Ho, Ann; Kreek, Mary Jeanne

    2012-01-01

    Cocaine addiction is a chronic relapsing disease with periods of chronic escalating self-exposure, separated by periods of abstinence/withdrawal of varying duration. Few studies compare such cycles in preclinical models. This study models an “addiction-like cycle” in mice to determine neurochemical/molecular alterations that underlie the chronic, relapsing nature of this disease. Groups of male C57BL/6J mice received acute cocaine exposure (14-day saline/14-day withdrawal /13-day saline + 1-d...

  10. Impacts of chronic sublethal exposure to clothianidin on winter honeybees.

    Science.gov (United States)

    Alkassab, Abdulrahim T; Kirchner, Wolfgang H

    2016-07-01

    A wide application of systemic pesticides and detection of their residues in bee-collected pollen and nectar at sublethal concentrations led to the emergence of concerns about bees' chronic exposure and possible sublethal effects on insect pollinators. Therefore, special attention was given to reducing unintentional intoxications under field conditions. The sensitivity of winter bees throughout their long lifespan to residual exposure of pesticides is not well known, since most previous studies only looked at the effects on summer bees. Here, we performed various laboratory bioassays to assess the effects of clothianidin on the survival and behavior of winter bees. Oral lethal and sublethal doses were administered throughout 12-day. The obtained LD50 values at 48, 72, 96 h and 10 days were 26.9, 18.0, 15.1 and 9.5 ng/bee, respectively. Concentrations <20 µg/kg were found to be sublethal. Oral exposure to sublethal doses was carried out for 12-day and, the behavioral functions were tested on the respective 13th day. Although slight reductions in the responses at the concentrations 10 and 15 µg/kg were observed, all tested sublethal concentrations had showed non-significant effects on the sucrose responsiveness, habitation of the proboscis extension reflex and olfactory learning performance. Nevertheless, chronic exposure to 15 µg/kg affected the specificity of the early long-term memory (24 h). Since the tested concentrations were in the range of field-relevant concentrations, our results strongly suggest that related-effects on winter and summer bees' sensitivity should also be studied under realistic conditions. PMID:27090425

  11. Health risks following exposure to aerosols produced by the use of depleted uranium weapons

    International Nuclear Information System (INIS)

    It is shown that recent incontrovertible evidence defines the existence of a very large error in the presently accepted model for the health consequences of exposure to low-level man-made radioactivity, and that therefore this same model which underpins the presently accepted assessment of harm from Depleted Uranium, is likely to be similarly flawed. In addressing this issue, the question is asked if Scientific Method has been properly used in the historical assessment of risk from exposure to low-level radiation, and it is suggested that it has not. In order to explain how DU may be having a serious impact on health at what is conventionally seen as low dose, the cellular and molecular basis of radiation action must be examined. Two possible mechanisms which address the particular type of radiation exposure involved with Depleted Uranium are outlined, and it is argued that these types of exposure cannot be modelled by the system of assessment of risk used by ICRP and based on the external irradiation which occurred at Hiroshima. Some evidence which supports this new model is briefly reviewed and it is shown how it applies to the Depleted Uranium controversy. Recent evidence on the dispersion of battlefield DU and its consequences is also reviewed. The structure of the lecture is as follows: 1. Background; 2. Depleted uranium: properties; 3. Errors in the ICRP low level radiation risk model (The Chernobyl Infants, Minisatellite DNA in Chernobyl children); 4. Radiation risk and Scientific Method; 5. Mechanistic considerations (Averaging dose, Cellular responses to radiation: the Burlakova dose response, The Second Event Theory, Second Events from DU particles, Energy density and risk, Beta emissions from DU, Environmental mobility of the DU particles, Conclusions on mechanism); 6. Sea coast cancer risks and resuspended hot particles; and 7. Recent evidence on DU exposure risks and response by UK government (DU, leukemia, cancer and birth defects in Iraq, DU in

  12. Impact of a chronic ingestion of radionuclides on cholesterol metabolism in the rat: example of depleted uranium and cesium 137

    International Nuclear Information System (INIS)

    Depleted uranium (DU) and cesium-137 (137Cs) are radionuclides spread in the environment due to industrial activities, incidents or accidents. This pollution sets a risk of human exposure to low levels of radiations through contaminated foodstuff. The impact of a chronic ingestion of DU or 137Cs on cholesterol metabolism in the liver and the brain has been studied. Indeed, cholesterol is crucial in physiology, being a component of cell membranes and a precursor to numerous molecules (bile acids...). Disruption of its metabolism is associated to many pathologies such as atherosclerosis or Alzheimer disease. Rats daily ingested a low level of DU or 137Cs over 9 months. For each radionuclide, a reference model (rats contaminated since adulthood) and a more sensitive model (hypercholesterolemic or contaminated since fetal life) were studied. The effects mainly consist of changes in gene expression or enzymatic activity of various actors of cholesterol metabolism. DU mainly affects one catabolism enzyme in both models, as well as membrane transporters and regulation factors. 137Cs mainly affects the storage enzyme in both models as well as catabolism enzymes, apolipoproteins, and regulation factors. No change in the plasma profile or in the tissue concentration of cholesterol (hepatic/cerebral) is recorded, whatever the model and the radionuclide. Thus, a chronic internal contamination with DU or 137Cs induces molecular modifications in cholesterol metabolism in the rat, without affecting its homeostasis or the general health status in all of our experimental models. (author)

  13. Individual monitoring of internal exposure to uranium oxides in two fuel fabrication plants

    International Nuclear Information System (INIS)

    Individual monitoring of personal exposure to inhalation of uranium oxides throughout the manufacture of fuel for pressurized water reactor (PWR) includes lung gamma-spectrometry, fecal analysis and urine analysis. Examination of the results shows the following: internal exposure is the consequence of repeated intake incidents as revealed by early peaks of urinary and particularly fecal elimination; a shift is often observed with the results of aerosol concentration measured through air collectors; the measured variations of uranium lung incorporations are relatively fast (apparent mean period 165 d). Correct evaluation of the effective dose equivalent from inhalation requires further information concerning the aerosol size distribution at work stations, the physico-chemical characteristics of the product leading to an estimate of its actual biological solubility, and the measurement of the fraction of aerosol liable to intake with an individual portable collector

  14. Chronic escalating cocaine exposure, abstinence/withdrawal, and chronic re-exposure: effects on striatal dopamine and opioid systems in C57BL/6J mice.

    Science.gov (United States)

    Zhang, Yong; Schlussman, Stefan D; Rabkin, Jacqui; Butelman, Eduardo R; Ho, Ann; Kreek, Mary Jeanne

    2013-04-01

    Cocaine addiction is a chronic relapsing disease with periods of chronic escalating self-exposure, separated by periods of abstinence/withdrawal of varying duration. Few studies compare such cycles in preclinical models. This study models an "addiction-like cycle" in mice to determine neurochemical/molecular alterations that underlie the chronic, relapsing nature of this disease. Groups of male C57BL/6J mice received acute cocaine exposure (14-day saline/14-day withdrawal/13-day saline + 1-day cocaine), chronic cocaine exposure (14 day cocaine) or chronic re-exposure (14-day cocaine/14-day withdrawal/14-day cocaine). Escalating-dose binge cocaine (15-30 mg/kg/injection × 3/day, i.p. at hourly intervals) or saline (14-day saline) was administered, modeling initial exposure. In "re-exposure" groups, after a 14-day injection-free period (modeling abstinence/withdrawal), mice that had received cocaine were re-injected with 14-day escalating-dose binge cocaine, whereas controls received saline. Microdialysis was conducted on the 14th day of exposure or re-exposure to determine striatal dopamine content. Messenger RNA levels of preprodynorphin (Pdyn), dopamine D1 (Drd1) and D2 (Drd2) in the caudate putamen were determined by real-time PCR. Basal striatal dopamine levels were lower in mice after 14-day escalating exposure or re-exposure than in those in the acute cocaine group and controls. Pdyn mRNA levels were higher in the cocaine groups than in controls. Long-term adaptation was observed across the stages of this addiction-like cycle, in that the effects of cocaine on dopamine levels were increased after re-exposure compared to exposure. Changes in striatal dopaminergic responses across chronic escalating cocaine exposure and re-exposure are a central feature of the neurobiology of relapsing addictive states. PMID:23164614

  15. MEASUREMENTS OF RADON, THORON, ISOTOPIC URANIUM AND THORIUM TO DETERMINE OCCUPATIONAL & ENVIRONMENTAL EXPOSURE & RISK AT FERNALD FEED MATERIALS PRODUCTION CENTER.

    Science.gov (United States)

    The research at the Fernald Environmental Restoration Management Corporation (FERMCO) site will provide radionuclide data, and realistic risk evaluation for isotopic radon, thorium, uranium and lead exposure.We have developed and tested a passive radon monitor with proven accur...

  16. In vivo measurements of lead-210 for assessing cumulative radon exposure in uranium miners

    International Nuclear Information System (INIS)

    It has long been recognized that a major contributor to the uncertainty in risk analysis of lung cancer in uranium and other hard rock miners is the estimation of total radon progeny exposure of individual miners under study. These uncertainties arise from the fact that only a limited number of measurements of airborne 222Rn progeny concentrations were made in the mines during the times that the miners were being exposed, and that dosimeters capable of integrating the Rn progeny exposures of the miners did not exist. Historically, the cumulative exposures for individual uranium and other hard rock miners have been calculated by combining the employee's work history, which may or may not have included time spent at different jobs within the mines and at different locations within the mines, with whatever periodic measurements of Rn and Rn progeny were available. The amount and quality of the measurement data varied enormously from mine to mine and from population to population. Because the quality of the exposure data collected during the period of active mining in the United STates cannot now be altered substantially, significant improvement in individual miner exposure estimates is only likely to be achieved if a new cumulative exposure metric is developed and implemented. The decay chain of Rn includes the production of 210Pb, which can accumulate in the skeleton in amounts proportional to the intake of Rn progeny. We hypothesize that the in vivo measurement of 210Pb in the skulls of miners will provide such a metric. In summary, the primary purpose of this pilot study to demonstrate the feasibility of measuring 210Pb in the heads of former uranium miners has been accomplished

  17. In vivo measurements of lead-210 for assessing cumulative radon exposure in uranium miners

    Energy Technology Data Exchange (ETDEWEB)

    Guilmette, R.A.; Laurer, G.R. [New York Univ. Inst. of Environmental Medicine, Tuxedo, NY (United States); Lambert, W.E.; Gilliland, F.D. [Univ. of New Mexico, Albuquerque, NM (United States)] [and others

    1995-12-01

    It has long been recognized that a major contributor to the uncertainty in risk analysis of lung cancer in uranium and other hard rock miners is the estimation of total radon progeny exposure of individual miners under study. These uncertainties arise from the fact that only a limited number of measurements of airborne {sup 222}Rn progeny concentrations were made in the mines during the times that the miners were being exposed, and that dosimeters capable of integrating the Rn progeny exposures of the miners did not exist. Historically, the cumulative exposures for individual uranium and other hard rock miners have been calculated by combining the employee`s work history, which may or may not have included time spent at different jobs within the mines and at different locations within the mines, with whatever periodic measurements of Rn and Rn progeny were available. The amount and quality of the measurement data varied enormously from mine to mine and from population to population. Because the quality of the exposure data collected during the period of active mining in the United STates cannot now be altered substantially, significant improvement in individual miner exposure estimates is only likely to be achieved if a new cumulative exposure metric is developed and implemented. The decay chain of Rn includes the production of {sup 210}Pb, which can accumulate in the skeleton in amounts proportional to the intake of Rn progeny. We hypothesize that the in vivo measurement of {sup 210}Pb in the skulls of miners will provide such a metric. In summary, the primary purpose of this pilot study to demonstrate the feasibility of measuring {sup 210}Pb in the heads of former uranium miners has been accomplished.

  18. Canine neoplasia and exposure to uranium mill tailings in Mesa County, Colorado

    International Nuclear Information System (INIS)

    A canine cancer registry was established for Mesa County, Colorado in order to collect material for a case control analysis of exposure to uranium tailings. Between 1979 and 1981, 212 cases of canine cancer were confirmed histologically. Based on the address provided at the time of diagnosis, 33 dogs (15.6%) lived in a house with some exposure to uranium tailings. A control group, comprised of dogs with a histologic diagnosis other than cancer, was stratified according to hospital and matched with cases on a 1:1 basis. No significant differences were noted with respect to exposure to uranium tailings for total cancers or cancers of specific sites including lymph node, breast, liver, testicle and bone. The overall estimated relative risk was 0.70 (95% CI 0.04 to 1.16). Canine population estimates were derived for Mesa County in order to develop crude incidence rates for the major types and sites of cancer. Crude rates were compared with those published previously for Alameda County, California and Tulsa County, Oklahoma. Mesa County rates for total cancer incidence, connective tissue tumors and non melanoma skin cancer were higher than those reported for Alameda County. When compared with Tulsa County, Mesa County rates for total cancer, breast cancer, melanoma and mastocytoma were lower than expected while rates for osteosarcoma, hemangiosarcoma and fibrosarcoma significantly exceeded expected values

  19. Effects of long-term chronic exposure to radionuclides in plant populations

    International Nuclear Information System (INIS)

    The results of field studies carried out on different plant species (winter rye and wheat, spring barley, oats, Scots pine, wild vetch, crested hairgrass) in various radioecological situations (nuclear weapon testing, the Chernobyl accident, uranium and radium processing) to investigate the effects of long-term chronic exposure to radionuclides are discussed. Plant populations growing in areas with relatively low levels of pollution are characterized by an increased level of both cytogenetic disturbances and genetic diversity. Although ionizing radiation causes primary damage at the molecular level, there are emergent effects at the level of populations, non-predictable from the knowledge of elementary mechanisms of cellular effects formation. Accumulation of cellular alterations may afterward influence biological parameters important for populations such as health and reproduction. Presented data provide evidence that in plant populations inhabiting heavily contaminated territories cytogenetic damage could be accompanied by a decrease in reproductive capacity. However, in less contaminated sites, because of the scarcity of data available, a steady relationship between cytogenetic effects and reproductive capacity was not revealed. Under radioactive contamination of the plant's environment, a population's resistance to exposure may increase. However, there are radioecological situations where an enhanced radioresistance has not evolved or has not persisted

  20. The Toxicity of Depleted Uranium

    Directory of Open Access Journals (Sweden)

    Wayne Briner

    2010-01-01

    Full Text Available Depleted uranium (DU is an emerging environmental pollutant that is introduced into the environment primarily by military activity. While depleted uranium is less radioactive than natural uranium, it still retains all the chemical toxicity associated with the original element. In large doses the kidney is the target organ for the acute chemical toxicity of this metal, producing potentially lethal tubular necrosis. In contrast, chronic low dose exposure to depleted uranium may not produce a clear and defined set of symptoms. Chronic low-dose, or subacute, exposure to depleted uranium alters the appearance of milestones in developing organisms. Adult animals that were exposed to depleted uranium during development display persistent alterations in behavior, even after cessation of depleted uranium exposure. Adult animals exposed to depleted uranium demonstrate altered behaviors and a variety of alterations to brain chemistry. Despite its reduced level of radioactivity evidence continues to accumulate that depleted uranium, if ingested, may pose a radiologic hazard. The current state of knowledge concerning DU is discussed.

  1. Background paper for regulations related to the exposure of uranium mine and mill workers

    International Nuclear Information System (INIS)

    The Atomic Energy Control Board is modifying the Atomic Energy Control Regulations to include a maximum permissible exposure to radon daughters for uranium mine and mill workers. In January 1976, after consultation with the uranium producers, union, and government regulatory bodies, the AECB issued a directive endorsing a maximum permissible annual occupational exposure to radon daughters of 4 Working Level Months (WLM). This exposure limit was an interim guideline to be applied for at least one year. The Board staff and members of the Mine Safety Advisory Committee have examined available evidence on the excess risk of lung cancer owing to exposure to radon daughters since then, and have assessed the arguments for both raising and lowering the exposure limit. The evidence is still not conclusive, and further studies, especially epidemiological ones, are needed. Nevertheless, the Board considers that the interim guideline is acceptable in the light of the present state of knowledge and that it should be incorporated into the regulations. This document explains why the Board has made this decision and discusses a number of related issues

  2. Unexpected Lack of Deleterious Effects of Uranium on Physiological Systems following a Chronic Oral Intake in Adult Rat

    OpenAIRE

    2014-01-01

    Uranium level in drinking water is usually in the range of microgram-per-liter, but this value may be as much as 100 to 1000 times higher in some areas, which may raise question about the health consequences for human populations living in these areas. Our purpose was to improve knowledge of chemical effects of uranium following chronic ingestion. Experiments were performed on rats contaminated for 9 months via drinking water containing depleted uranium (0.2, 2, 5, 10, 20, 40, or 120 mg/L). B...

  3. Memory Deficit Recovery after Chronic Vanadium Exposure in Mice

    Directory of Open Access Journals (Sweden)

    Oluwabusayo Folarin

    2016-01-01

    Full Text Available Vanadium is a transitional metal with an ability to generate reactive oxygen species in the biological system. This work was designed to assess memory deficits in mice chronically exposed to vanadium. A total of 132 male BALB/c mice (4 weeks old were used for the experiment and were divided into three major groups of vanadium treated, matched controls, and animals exposed to vanadium for three months and thereafter vanadium was withdrawn. Animals were tested using Morris water maze and forelimb grip test at 3, 6, 9, and 12 months of age. The results showed that animals across the groups showed no difference in learning but had significant loss in memory abilities after 3 months of vanadium exposure and this trend continued in all vanadium-exposed groups relative to the controls. Animals exposed to vanadium for three months recovered significantly only 9 months after vanadium withdrawal. There was no significant difference in latency to fall in the forelimb grip test between vanadium-exposed groups and the controls in all age groups. In conclusion, we have shown that chronic administration of vanadium in mice leads to memory deficit which is reversible but only after a long period of vanadium withdrawal.

  4. Ultrastructural effects on gill, muscle, and gonadal tissues induced in zebrafish (Danio rerio) by a waterborne uranium exposure

    Energy Technology Data Exchange (ETDEWEB)

    Barillet, Sabrina, E-mail: sabrina.barillet@free.fr [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological Protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France); Larno, Valerie, E-mail: valerie.larno@irsn.fr [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological Protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France); Floriani, Magali, E-mail: magali.floriani@irsn.fr [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological Protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France); Devaux, Alain, E-mail: alain.devaux@entpe.fr [INRA, EFPA Department, 54280, Champenoux and Environmental Science Laboratory, ENTPE, 69518 Vaulx en Velin cedex (France); Adam-Guillermin, Christelle, E-mail: christelle.adam-guillermin@irsn.fr [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological Protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France)

    2010-11-01

    Experiments on adult zebrafish (Danio rerio) were conducted to assess histopathological effects induced on gill, muscle, and gonadal tissues after waterborne uranium exposure. Although histopathology is often employed as a tool for the detection and assessment of xenobiotic-mediated effects in aquatic organisms, few studies have been dedicated to the investigation of histopathological consequences of uranium exposure in fish. Results showed that gill tissue architecture was markedly disrupted. Major symptoms were alterations of the secondary lamellae epithelium (from extensive oedema to desquamation), hyperplasia of chloride cells, and breakdown of the pillar cell system. Muscle histology was also affected. Degeneration and disorganization of myofibrillar sarcomeric pattern as well as abnormal localization of mitochondria within muscle and altered endomysial sheaths were observed. Morphological alterations of spermatozoa within the gonadal tissue were also noticed. This study demonstrated that uranium exposure induced a variety of histological impairments in fish, supporting environmental concerns when uranium contaminates aquatic systems.

  5. Substrate-enzyme characteristics after derangements of biological combustion processes. Estimations of organism's long term exposure to uranium ore dust

    International Nuclear Information System (INIS)

    Under uranium-mining and processing conditions industrial dust of uranium ore (IDO) is key anthropogenic factor of effect on organism. Industrial dust of uranium ore contains trace of 238uranium oxide making effects of low and ultralow radiation doses along with silicon derivatives, salts of heavy metals and other contaminants. In recent years epidemiological studies showed that along with commonly encountered radiation- induced pathology in zones with radiation problems general somatic morbidity with symptoms of chronic disease with protracted course essentially increased. Above-mentioned facts indicate the exigency of systematized study the nature of systemic effect of ionizing radiation on organism at low doses. Structural and functional irregularities, metabolic imbalances and dyscrasia induced by irradiation can become indicators in this direction. Biological combustion processes performing complex of reductive and oxidative conversions directed to energy-rich compound synthesis occupy a special place among highly sensitive and informative homeostasis systems. In order to reveal the nature of ionizing radiation effect on organism at low doses and search for a relation 'Dose - Effect' we carried out series experiments with different doses of industrial dust of uranium ore from Stepnogorsk mining and chemical complex. Dose load calculation was carried out with a glance for threshold limit value (TLV) of dust control in work zone. Three dose loads satisfied to 5, 10, and 50 times to TLV were studied. Total time on inhalation primer makes up 120 days at doses equal to 5 and 10 times TLV and 60 days at dose 50 times TLV Value of total accumulated dose in the first two series varies within 11 and 22 micro Sv per 120 days of inhalation and is 55 micro Sv per 60 days in the third series. Substrate - enzyme relationships of three energy systems: terminal stages of glycolysis, intermediates and enzymes from Krebs cycle, as well as certain products from lipid

  6. Assessment of gamma radiation exposure to drivers (contractual) engaged with transporting of uranium ore in uranium mines at Narwapahar Mines, India

    International Nuclear Information System (INIS)

    Due to radioactive nature of uranium ore and tailings sand, it is essential to assess the exposure of drivers and helpers, those are continuously engaged with transporting of it. The external exposure is due to gamma radiation, emitted by uranium progeny and its magnitude is therefore directly related to the ore grade. The major gamma emitters in the series are 214Pb and 214Bi. After uranium recovery in ore processing areas the waste generated in mill contains same magnitude of gamma emitters. Tailings sand is the waste generated from mill area, which is used for back filling in underground mine. This paper presents the results of estimation of external gamma radiation levels during transport and assesses the radiation dose to drivers and helpers

  7. Occupational exposure to radon in non-uranium underground mines in the Philippines

    International Nuclear Information System (INIS)

    One of the occupational risks of mining ore results from the exposures of miners to radon gas, a radioactive gas that occurs naturally in rocks and soils. The inhalation of this radionuclide constitutes the most important occupational exposure in uranium mines, as well as in non-uranium underground mines and underground work places where ventilation is insufficient. In the Philippines, nine underground metallurgical and coal mines where monitored for radon. Data shows that the activity concentrations of radon in these mines ranged from 30 to 347Bq/m3. The annual average potential alpha energy exposure of workers in the mines ranged from 0.02 to 0.06 WLM. These values correspond to an annual effective dose equivalent of 0.15 to 0.5 mSv, respectively. It was found that the levels of radon in Philippine underground mines were below the action level (1000 Bq/m3) set by the International Commission on Radiological Protection (ICRP) and were below the levels of human health concerns. (author)

  8. Unexpected Lack of Deleterious Effects of Uranium on Physiological Systems following a Chronic Oral Intake in Adult Rat

    Directory of Open Access Journals (Sweden)

    Isabelle Dublineau

    2014-01-01

    Full Text Available Uranium level in drinking water is usually in the range of microgram-per-liter, but this value may be as much as 100 to 1000 times higher in some areas, which may raise question about the health consequences for human populations living in these areas. Our purpose was to improve knowledge of chemical effects of uranium following chronic ingestion. Experiments were performed on rats contaminated for 9 months via drinking water containing depleted uranium (0.2, 2, 5, 10, 20, 40, or 120 mg/L. Blood biochemical and hematological indicators were measured and several different types of investigations (molecular, functional, and structural were conducted in organs (intestine, liver, kidneys, hematopoietic cells, and brain. The specific sensitivity of the organs to uranium was deduced from nondeleterious biological effects, with the following thresholds (in mg/L: 0.2 for brain, >2 for liver, >10 for kidneys, and >20 for intestine, indicating a NOAEL (No-Observed-Adverse-Effect Level threshold for uranium superior to 120 m g/L. Based on the chemical uranium toxicity, the tolerable daily intake calculation yields a guideline value for humans of 1350 μg/L. This value was higher than the WHO value of 30 μg/L, indicating that this WHO guideline for uranium content in drinking water is very protective and might be reconsidered.

  9. Uranium

    International Nuclear Information System (INIS)

    Canada produced one-third of the Western World's uranium production in 1989, twice as much from Saskatchewan as from Ontario, where mine closures have led to the loss of over 2,000 jobs. Canadian production in 1990 was about 8.8 Gg U. In 1990, Canada's primary producers were Denison Mines, Rio Algom, Cluff Mining, and Cameco. In Saskatchewan, there are three operations: Key Lake, Rabbit Lake/Collins Bay, and Cluff Lake. Canada stands fourth in uranium resources, but because of favourable geology remains the focus of much exploration activity, which cost about C$60 in 1989. Large stockpiles overhang the market, so new sources of uranium will not be needed before the mid 1990's, but long-term prospects seem good

  10. Uranium

    International Nuclear Information System (INIS)

    The uranium production industry is well into its third recession during the nuclear era (since 1945). Exploration is drastically curtailed, and many staffs are being reduced. Historical market price production trends are discussed. A total of 3.07 million acres of land was acquired for exploration; drastic decrease. Surface drilling footage was reduced sharply; an estimated 250 drill rigs were used by the uranium industry during 1980. Land acquisition costs increased 8%. The domestic reserve changes are detailed by cause: exploration, re-evaluation, or production. Two significant discoveries of deposits were made in Mohave County, Arizona. Uranium production during 1980 was 21,850 short tons U3O8; an increase of 17% from 1979. Domestic and foreign exploration highlights were given. Major producing areas for the US are San Juan basin, Wyoming basins, Texas coastal plain, Paradox basin, northeastern Washington, Henry Mountains, Utah, central Colorado, and the McDermitt caldera in Nevada and Oregon. 3 figures, 8 tables

  11. Chronic obstructive pulmonary disease (COPD and occupational exposures

    Directory of Open Access Journals (Sweden)

    Zeni Elena

    2006-06-01

    Full Text Available Abstract Chronic obstructive pulmonary disease (COPD is one of the leading causes of morbidity and mortality in both industrialized and developing countries. Cigarette smoking is the major risk factor for COPD. However, relevant information from the literature published within the last years, either on general population samples or on workplaces, indicate that about 15% of all cases of COPD is work-related. Specific settings and agents are quoted which have been indicated or confirmed as linked to COPD. Coal miners, hard-rock miners, tunnel workers, concrete-manufacturing workers, nonmining industrial workers have been shown to be at highest risk for developing COPD. Further evidence that occupational agents are capable of inducing COPD comes from experimental studies, particularly in animal models. In conclusion, occupational exposure to dusts, chemicals, gases should be considered an established, or supported by good evidence, risk factor for developing COPD. The implications of this substantial occupational contribution to COPD must be considered in research planning, in public policy decision-making, and in clinical practice.

  12. Long-term exposure to depleted uranium in Gulf-War veterans does not induce chromosome aberrations in peripheral blood lymphocytes.

    Science.gov (United States)

    Bakhmutsky, Marina V; Squibb, Katherine; McDiarmid, Melissa; Oliver, Marc; Tucker, James D

    2013-10-01

    Depleted uranium (DU) is a high-density heavy metal that has been used in munitions since the 1991 Gulf War. DU is weakly radioactive and chemically toxic, and long-term exposure may cause adverse health effects. This study evaluates genotoxic effects of exposure to DU by measuring chromosome damage in peripheral blood lymphocytes with fluorescence in situ hybridization whole-chromosome painting. Study participants are Gulf War-I Veterans with embedded DU fragments and/or inhalation exposure due to involvement in friendly-fire incidents; they are enrolled in a long-term health surveillance program at the Baltimore Veterans Administration Medical Center. Blood was drawn from 35 exposed male veterans aged 39 to 62 years. Chromosomes 1, 2, and 4 were painted red and chromosomes 3, 5, and 6 were simultaneously labeled green. At least 1800 metaphase cells per subject were scored. Univariate regression analyses were performed to evaluate the effects of log(urine uranium), age at time of blood draw, log(lifetime X-rays), pack-years smoked and alcohol use, against frequencies of cells with translocated chromosomes, dicentrics, acentric fragments, color junctions and abnormal cells. No significant relationships were observed between any cytogenetic endpoint and log(urine uranium) levels, smoking, or log(lifetime X-rays). Age at the time of blood draw showed significant relationships with all endpoints except for cells with acentric fragments. Translocation frequencies in these Veterans were all well within the normal range of published values for healthy control subjects from around the world. These results indicate that chronic exposure to DU does not induce significant levels of chromosome damage in these Veterans. PMID:23933231

  13. Laser Ablation-ICP MS of Hair Strands as a Means for Assessment of Internal Exposure to Uranium

    International Nuclear Information System (INIS)

    Assessment of internal exposure to uranium is generally carried out by analysis of urine samples, and correlating the result according to the ICRP bio-kinetic mode. Hair samples can also be used for a sensitive bio monitoring of environmental or occupational exposure. There are several advantages to analyze hair samples rather than urine. First, hair is an effective bio-concentrator for uranium and is a major excretion pathway. Second, hair samples are stable and the uranium content does not change over time. Third, hair does not require special storage and handling. And finally, hair has the unique ability to reflect the total body intake during an extended period and it is possible to trace changes over time. These features were recently demonstrated in a comprehensive joint study by groups from Finland and Israel, where hair samples were rinsed, digested and the uranium level determined by inductively coupled plasma - mass spectrometry (ICP MS). If an occupational exposure incident occurs, urine samples must be collected shortly after the incident and then several more samples need to be acquired until the uranium in urine concentration returns to its normal level. Hair samples can be collected several days, or even weeks, after the incident and the uranium content can be measured along a single strand to reflect the level before, during and after the incident in a single series of measurements with a laser-ablation ICP MS instrument

  14. Late health effects of chronic radiation exposure of bone marrow

    Energy Technology Data Exchange (ETDEWEB)

    Yarmoshenko, Ilia V.; Malinovsky, Georgy P.; Konshina, Lidia G.; Zhukovsky, Michael V. [Institute of Industrial Ecology UB RAS, 620219, 20, Sophy Kovalevskoy St., Ekaterinburg (Russian Federation); Tuzankina, Irina A. [Institute of Immunology and Physiology UB RAS, 620049, 106, Pervomayskaya St., Ekaterinburg (Russian Federation)

    2014-07-01

    infectious etiology, which are unexpected due to low doses absorbed in those organs and tissues. To analyze the unexpected results recent findings on strong attributability of stomach, liver and cervix cancers to bacterial and viral infections was taken into account. According to IARC, stomach cancer relative risk associated with helicobacter pillory is 5.6, liver cancer relative risks associated with HBV and HCV are 23 and 17 respectively, cervix cancer relative risk associated with HPV is >100. At the same time association of lung cancer, colon cancer and some other common malignancies with infections is either not established or of low significance. To explain observed effects we suggested that excess mortality due to cancer and non-cancer diseases of infectious etiology is associated with radiation exposure of bone marrow due to Sr-90. Irradiation of hematopoietic stem cells and progenitor cells damages hematopoiesis and suppresses the immune response. Secondary immune deficiency induced by chronic radiation increases susceptibility to the bacterial and viral infections. Such late effect of radiation exposure can be considered within the concept of deterministic tissue reactions. (Under support of UB RAS project 12-P-2-1033). (authors)

  15. Late health effects of chronic radiation exposure of bone marrow

    International Nuclear Information System (INIS)

    etiology, which are unexpected due to low doses absorbed in those organs and tissues. To analyze the unexpected results recent findings on strong attributability of stomach, liver and cervix cancers to bacterial and viral infections was taken into account. According to IARC, stomach cancer relative risk associated with helicobacter pillory is 5.6, liver cancer relative risks associated with HBV and HCV are 23 and 17 respectively, cervix cancer relative risk associated with HPV is >100. At the same time association of lung cancer, colon cancer and some other common malignancies with infections is either not established or of low significance. To explain observed effects we suggested that excess mortality due to cancer and non-cancer diseases of infectious etiology is associated with radiation exposure of bone marrow due to Sr-90. Irradiation of hematopoietic stem cells and progenitor cells damages hematopoiesis and suppresses the immune response. Secondary immune deficiency induced by chronic radiation increases susceptibility to the bacterial and viral infections. Such late effect of radiation exposure can be considered within the concept of deterministic tissue reactions. (Under support of UB RAS project 12-P-2-1033). (authors)

  16. Temperature modulates phototrophic periphyton response to chronic copper exposure.

    Science.gov (United States)

    Lambert, Anne Sophie; Dabrin, Aymeric; Morin, Soizic; Gahou, Josiane; Foulquier, Arnaud; Coquery, Marina; Pesce, Stéphane

    2016-01-01

    Streams located in vineyard areas are highly prone to metal pollution. In a context of global change, aquatic systems are generally subjected to multi-stress conditions due to multiple chemical and/or physical pressures. Among various environmental factors that modulate the ecological effects of toxicants, special attention should be paid to climate change, which is driving an increase in extreme climate events such as sharp temperature rises. In lotic ecosystems, periphyton ensures key ecological functions such as primary production and nutrient cycling. However, although the effects of metals on microbial communities are relatively well known, there is scant data on possible interactions between temperature increase and metal pollution. Here we led a study to evaluate the influence of temperature on the response of phototrophic periphyton to copper (Cu) exposure. Winter communities, collected in a 8 °C river water, were subjected for six weeks to four thermal conditions in microcosms in presence or not of Cu (nominal concentration of 15 μg L(-1)). At the initial river temperature (8 °C), our results confirmed the chronic impact of Cu on periphyton, both in terms of structure (biomass, distribution of algal groups, diatomic composition) and function (photosynthetic efficiency). At higher temperatures (13, 18 and 23 °C), Cu effects were modulated. Indeed, temperature increase reduced Cu effects on algal biomass, algal class proportions, diatom assemblage composition and photosynthetic efficiency. This reduction of Cu effects on periphyton may be related to lower bioaccumulation of Cu and/or to selection of more Cu-tolerant species at higher temperatures. PMID:26608872

  17. Biological characterization of radiation exposure and dose estimates for inhaled uranium milling effluents. Annual progress report, April 1981-March 1982

    International Nuclear Information System (INIS)

    The problems addressed are the protection of uranium will workers from occupational exposure to uranium through routine bioassay programs and the assessment of accidental worker exposures. Comparisons of chemical properties and the biological behavior of refined uranium ore (yellowcake) are made to identify important properties that influence uranium distribution patterns among organs. These studies will facilitate calculations of organ doses for specific exposures and associated health risk estimates and will identify important bioassay procedures to improve evaluations of human exposures. Sampling of airborne yellowcake at four uranium mills showed that aerosols were heterogeneous, changed with time and contained approx. 50% of the airborne uranium in particles greater than 12 μm aerodynamic diameter. Results are related to specific packaging steps and to predictions of appreciable upper respiratory tract deposition rates for the aerosols, if inhaled by a worker without respiratory protection. Previously used in vitro dissolution techniques were evaluated and the uses of the results for interpreting urinary bioassay data are described. Preliminary results from an inhalation experiment using rats indicate that the clearance patterns of inhaled uranium from lung agreed quantitatively with results from in vitro dissolution and infrared analyses of the yellowcake used. Preliminary results from an experiment to simulate contamination of a wound by yellowcake showed that more of the implanted dose of a less soluble form of yellowcake was retained at the wound site than of a more soluble form at 32 days after implantation. The results did not quantitatively agree with in vitro dissolution results. A two-year study of yellowcake from two mills was initiated. Twenty Beagle dogs were exposed by nose-only inhalation to a more soluble form of yellowcake and 20 to a less soluble form

  18. Sub-chronic exposure to second hand smoke induces airspace leukocyte infiltration and decreased lung elastance

    OpenAIRE

    Hartney, John M.; Chu, HongWei; Pelanda, Roberta; Torres, Raul M.

    2012-01-01

    Exposure to second hand tobacco smoke is associated with the development and/or exacerbation of several different pulmonary diseases in humans. To better understand the possible effects of second hand smoke exposure in humans, we sub-chronically (4 weeks) exposed mice to a mixture of mainstream and sidestream tobacco smoke at concentrations similar to second hand smoke exposure in humans. The inflammatory response to smoke exposures was assessed at the end of this time by enumeration of pulmo...

  19. Effects of Chronic Manganese Exposure on Cognitive and Motor Functioning in Non-Human Primates

    OpenAIRE

    Schneider, Jay S.; Decamp, Emmanuel; Koser, Amy Jo; Fritz, Stephanie; Gonczi, Heather; Syversen, Tore; Guilarte, Tomás R.

    2006-01-01

    Acute exposure to manganese is associated with complex behavioral/psychiatric signs that may include Parkinsonian motor features. However, little is known about the behavioral consequences of chronic manganese exposures. In this study, cynomolgus macaque monkeys were exposed to manganese sulfate (10 –15 mg/kg/week) over an exposure period lasting 272 ± 17 days. Prior to manganese exposure, animals were trained to perform tests of cognitive and motor functioning and overall behavior was assess...

  20. Cell proliferation and cell death are disturbed during prenatal and postnatal brain development after uranium exposure.

    Science.gov (United States)

    Legrand, M; Elie, C; Stefani, J; N Florès; Culeux, C; Delissen, O; Ibanez, C; Lestaevel, P; Eriksson, P; Dinocourt, C

    2016-01-01

    The developing brain is more susceptible to neurotoxic compounds than adult brain. It is also well known that disturbances during brain development cause neurological disorders in adulthood. The brain is known to be a target organ of uranium (U) exposure and previous studies have noted that internal U contamination of adult rats induces behavioral disorders as well as affects neurochemistry and neurophysiological properties. In this study, we investigated whether depleted uranium (DU) exposure affects neurogenesis during prenatal and postnatal brain development. We examined the structural morphology of the brain, cell death and finally cell proliferation in animals exposed to DU during gestation and lactation compared to control animals. Our results showed that DU decreases cell death in the cortical neuroepithelium of gestational day (GD) 13 embryos exposed at 40mg/L and 120mg/L and of GD18 fetuses exposed at 120mg/L without modification of the number of apoptotic cells. Cell proliferation analysis showed an increase of BrdU labeling in the dentate neuroepithelium of fetuses from GD18 at 120mg/L. Postnatally, cell death is increased in the dentate gyrus of postnatal day (PND) 0 and PND5 exposed pups at 120mg/L and is associated with an increase of apoptotic cell number only at PND5. Finally, a decrease in dividing cells is observed in the dentate gyrus of PND21 rats developmentally exposed to 120mg/L DU, but not at PND0 and PND5. These results show that DU exposure during brain development causes opposite effects on cell proliferation and cell death processes between prenatal and postnatal development mainly at the highest dose. Although these modifications do not have a major impact in brain morphology, they could affect the next steps of neurogenesis and thus might disrupt the fine organization of the neuronal network. PMID:26506049

  1. The oxidation of uranium hydride during its instantaneous or gradual exposure to oxygen

    International Nuclear Information System (INIS)

    The oxidation behaviour of uranium hydride when exposed to oxygen gas either gradually or instantaneously at an ambient temperature of approximately 37 °C has been investigated. The proportion of the sample converted to oxide and the mean hydride mound temperature rise accompanying the oxidation process were recorded. Pressure changes in the reaction cell were used to deduce the nature of the oxide generated during the oxidation process and the nature of the gaseous reaction products. For the gradual oxidation of the hydride, typically only about 15% of the hydride mass was converted to oxide during the initial period of oxidation defined by an observed temperature excursion lasting a finite time; during this oxidation period it is concluded that, despite the only moderate recoded mean temperature rises, the generated oxide is U3O8 rather than UO2. Typically also for such gradual exposure experiments, hydrogen was the principal gaseous reaction product with negligible water being produced. For the instantaneous exposure of the hydride to oxygen, much higher hydride mound mean temperature rises were recorded but the proportion of hydride converted to oxide was quite variable and apparently dependent on several experimental variables; for these experiments, although hydrogen was a major reaction product typically some water was also produced. The boundary between pyrophoric and non-pyrophoric oxidation of uranium hydride for given oxidising conditions is discussed in terms of a calculated particle “thermal runaway temperature”. - Highlights: • Only about 15% of UH3 is oxidised on its gradual exposure to oxygen. • During the gradual exposure of UH3 to oxygen U3O8 rather than UO2 is generated. • For such gradual exposure, predominantly H2 rather than H2O was generated. • For the instantaneous exposure of UH3 to O2 the amount oxidised was variable. • For these experiments, H2 + some H2O was generally produced. • Pyrophoric or non-pyrophoric behaviour

  2. The oxidation of uranium hydride during its instantaneous or gradual exposure to oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Glascott, J., E-mail: joe.glascott@awe.co.uk; Findlay, I.M.

    2015-11-15

    The oxidation behaviour of uranium hydride when exposed to oxygen gas either gradually or instantaneously at an ambient temperature of approximately 37 °C has been investigated. The proportion of the sample converted to oxide and the mean hydride mound temperature rise accompanying the oxidation process were recorded. Pressure changes in the reaction cell were used to deduce the nature of the oxide generated during the oxidation process and the nature of the gaseous reaction products. For the gradual oxidation of the hydride, typically only about 15% of the hydride mass was converted to oxide during the initial period of oxidation defined by an observed temperature excursion lasting a finite time; during this oxidation period it is concluded that, despite the only moderate recoded mean temperature rises, the generated oxide is U{sub 3}O{sub 8} rather than UO{sub 2}. Typically also for such gradual exposure experiments, hydrogen was the principal gaseous reaction product with negligible water being produced. For the instantaneous exposure of the hydride to oxygen, much higher hydride mound mean temperature rises were recorded but the proportion of hydride converted to oxide was quite variable and apparently dependent on several experimental variables; for these experiments, although hydrogen was a major reaction product typically some water was also produced. The boundary between pyrophoric and non-pyrophoric oxidation of uranium hydride for given oxidising conditions is discussed in terms of a calculated particle “thermal runaway temperature”. - Highlights: • Only about 15% of UH{sub 3} is oxidised on its gradual exposure to oxygen. • During the gradual exposure of UH{sub 3} to oxygen U{sub 3}O{sub 8} rather than UO{sub 2} is generated. • For such gradual exposure, predominantly H{sub 2} rather than H{sub 2}O was generated. • For the instantaneous exposure of UH{sub 3} to O{sub 2} the amount oxidised was variable. • For these experiments, H{sub 2

  3. Biomarkers for assessing potential carcinogenic effects of chronic arsenic exposure in Inner Mongolia, CHINA

    Science.gov (United States)

    Arsenic is ubiquitous in the environment. Chronic arsenic exposure via drinking water has been associated. with carcinogenic, cardiovascular, neurological and diabetic effects in humans and has been of great public health concern worldwide. In 2001, U.S. Environmental Protection ...

  4. The Impact of Chronic Pesticide Exposure on Neuropsychological Functioning

    Science.gov (United States)

    Schultz, Caitlin G.; Ferraro, F. Richard

    2013-01-01

    This study compared neuropsychological test performance of individuals (n = 18) with an occupational history of pesticide exposure to individuals (n = 35) with no such exposure history. Results showed that a history of pesticide-related occupation exposure led to deficits in only Digit Symbol performance. Additionally, the correlation between…

  5. Functional Alterations in the Dorsal Raphe Nucleus Following Acute and Chronic Ethanol Exposure

    OpenAIRE

    Lowery-Gionta, Emily G; Marcinkiewcz, Catherine A.; Kash, Thomas L.

    2014-01-01

    Alcoholism is a pervasive disorder perpetuated in part to relieve negative mood states like anxiety experienced during alcohol withdrawal. Emerging evidence demonstrates a role for the serotonin-rich dorsal raphe (DR) in anxiety following ethanol withdrawal. The current study examined the effects of chronic ethanol vapor exposure on the DR using slice electrophysiology in male DBA2/J mice. We found that chronic ethanol exposure resulted in deficits in social approach indicative of increased a...

  6. Chronic exposure of low dose salinomycin inhibits MSC migration capability in vitro

    OpenAIRE

    Scherzad, Agmal; HACKENBERG, STEPHAN; FROELICH, KATRIN; RAK, KRISTEN; HAGEN, RUDOLF; TAEGER, JOHANNES; BREGENZER, MAXIMILLIAN; KLEINSASSER, NORBERT

    2016-01-01

    Salinomycin is a polyether antiprotozoal antibiotic that is used as a food additive, particularly in poultry farming. By consuming animal products, there may be a chronic human exposure to salinomycin. Salinomycin inhibits the differentiation of preadipocytes into adipocytes. As human mesenchymal stem cells (MSC) may differentiate into different mesenchymal cells, it thus appeared worthwhile to investigate whether chronic salinomycin exposure impairs the functional properties of MSC and induc...

  7. Study of the biological effects of uranium exposure on zebra fish (D. rerio). Impact on life stages; Etude des effets biologiques de l'exposition a l'uranium chez le poisson zebre (D. rerio). Impact sur les stades de vie

    Energy Technology Data Exchange (ETDEWEB)

    Bourrachot, St.

    2009-05-15

    This work is part of an ongoing project (ENVIRHOM) started at IRSN in 2000, which consists in studying the environmental effects of radioactive substances at chronic low level of exposure. In this general frame, our aim was two fold: (i) to identify sensitivity of different critical life stages of zebra fish (fish of fresh water frequently used for tests standards in ecotoxicology) to uranium exposure and (ii) to evaluate underlying mechanisms. Experiments were conducted with eggs, larvae and genitors exposed to uranium at environmentally relevant concentrations (from 20 to 500 {mu}g/L) in order to study survival, hatching of eggs, growth of larvae and reproduction of genitors. Bio-markers of exposure (i.e. U bioaccumulation) and bio-markers of effects at molecular level (i.e. genotoxic effects, reproductive-toxicity) were also measured. Sensitivity of fish to uranium was dependent of the life stage of development with the early life stage being the most sensitive to U either directly or maternally exposed. It underlines the relevance of including pro-larval stages for toxicity assessments in fish. Moreover drastic effects of uranium on reproductive success and DNA damages in the germ cells foretell a strong impact on the population for low concentration of exposure (20 {mu}g/L). As it is increasingly recognized that population-level effects of toxic substances are more relevant in terms of ecological risk assessment, this study points out the need to include different life stages of organisms in eco-toxicological studies, especially the sensitive early stages. Moreover, it appears, through the comparative study of the radiological effects or by another isotope of the uranium of stronger radioactivity ({sup 233}U or by an irradiation with {sup 137}Cs), that the effects of the uranium are due to its chemo-toxicity. (author)

  8. Inflammatory and Remodeling Events in Asthma with Chronic Exposure to House Dust Mites: A Murine Model

    OpenAIRE

    Ahn, Joong Hyun; Kim, Chi Hong; Kim, Yong Hyun; Kim, Seung Joon; Lee, Sook-Young; Kim, Young Kyoon; Kim, Kwan Hyoung; Moon, Hwa Sik; Song, Jeong Sup; Park, Sung Hak; Kwon, Soon Seog

    2007-01-01

    Although animal models with ovalbumin have been used to study chronic asthma, there are difficulties in inducing recurrence as well as in maintaining chronic inflammation in this system. Using a murine model of house dust mite (HDM)-induced bronchial asthma, we examined the airway remodeling process in response to the chronic exposure to HDM. During the seventh and twelfth weeks of study, HDM were inhaled through the nose for three consecutive days and airway responsiveness was measured. Twen...

  9. The metabolic behaviour of uranium octoxide bearing residues after their deposition in the rat lung: the implications for occupational exposure

    International Nuclear Information System (INIS)

    This paper describes the metabolic behaviour in rats of uranium inhaled as a U3O8 bearing residue. The biokinetic behaviour of uranium in workers has been predicted by combining the transfer rates to blood in rats with mucociliary clearance rates obtained from human volunteers exposed to other aerosols. It is concluded that chest monitoring will be of value for assessing acute and chronic intakes of the residue below the proposed annual limit (6 x 103 Bq) whilst urinary excretion data should be interpreted with caution. (author)

  10. Assessing potential risks from exposure to natural uranium in well water

    Energy Technology Data Exchange (ETDEWEB)

    Hakonson-Hayes, A.C.; Fresquez, P.R. E-mail: fresquezp@lanl.gov; Whicker, F.W

    2002-07-01

    Over 50% of the wells in the Nambe region of northern New Mexico exceed the US Environmental Protection Agency's recommended drinking water standard of 20 {mu}g l{sup -1} for {sup 238}U; the highest in the area was measured at 1200 {mu}g U l{sup -1}. Uranium uptake was estimated in tomato (Lycopersicon esculentum), squash (Cucurbita pepo), lettuce (Lactuca scarriola), and radish (Raphanus sativus) irrigated with Nambe well water containing <1, 150, 500, and 1200 {mu}g U l{sup -1}. Plant uptake and human dose and toxicity associated with ingestion of water and produce and inhalation of irrigated soil related to gardening activities were evaluated. Uranium concentration in plants increased linearly with increasing U concentration in irrigation water, particularly in lettuce and radish. The estimated total committed effective dose for 70 years of maximum continuous exposure, via the three pathways to well water containing 1200 {mu}g U l{sup -1}, was 0.17 mSv with a corresponding kidney concentration of 0.8 {mu}g U g{sup -1} kidney.

  11. Assessing potential risks from exposure to natural uranium in well water

    International Nuclear Information System (INIS)

    Over 50% of the wells in the Nambe region of northern New Mexico exceed the US Environmental Protection Agency's recommended drinking water standard of 20 μg l-1 for 238U; the highest in the area was measured at 1200 μg U l-1. Uranium uptake was estimated in tomato (Lycopersicon esculentum), squash (Cucurbita pepo), lettuce (Lactuca scarriola), and radish (Raphanus sativus) irrigated with Nambe well water containing -1. Plant uptake and human dose and toxicity associated with ingestion of water and produce and inhalation of irrigated soil related to gardening activities were evaluated. Uranium concentration in plants increased linearly with increasing U concentration in irrigation water, particularly in lettuce and radish. The estimated total committed effective dose for 70 years of maximum continuous exposure, via the three pathways to well water containing 1200 μg U l-1, was 0.17 mSv with a corresponding kidney concentration of 0.8 μg U g-1 kidney

  12. Effect of Chronic Exposure to Acidic Environment on Radiosensitivity of Gliosarcoma Cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sora; Kim, Eunhee [Seoul National Univ., Seoul (Korea, Republic of)

    2014-05-15

    In this study, the chronic exposure of cells to acid culture medium, prior or posterior to irradiation, has been investigated for its effect on clonogenic cell survival. Unconventional high-dose radiation therapy, such as SRS, SBRT and MRT, may cause severe vascular damage in tumors, thereby a number of tumor cells facing chronic hypoxia and thus acidosis. According to our observation, gliosarcoma cells become more vulnerable to radiation damage by chronic exposure to acidic condition before irradiation. The longer the preirradiation exposure is, the more vulnerable to radiation damage the cells become. However, the repair of PLD by post-irradiation exposure to acid medium is efficient enough to eliminate the difference in number of the cells carrying PLDs due to different durations of preirradiation exposure to acidic condition.

  13. A novel antibody-based biomarker for chronic algal toxin exposure and sub-acute neurotoxicity

    Science.gov (United States)

    Lefebvre, Kathi A.; Frame, Elizabeth R.; Gulland, Frances; Hansen, John D.; Kendrick, Preston S.; Beyer, Richard P.; Bammler, Theo K.; Farin, Frederico M.; Hiolski, Emma M.; Smith, Donald R.; Marcinek, David J.

    2012-01-01

    The neurotoxic amino acid, domoic acid (DA), is naturally produced by marine phytoplankton and presents a significant threat to the health of marine mammals, seabirds and humans via transfer of the toxin through the foodweb. In humans, acute exposure causes a neurotoxic illness known as amnesic shellfish poisoning characterized by seizures, memory loss, coma and death. Regular monitoring for high DA levels in edible shellfish tissues has been effective in protecting human consumers from acute DA exposure. However, chronic low-level DA exposure remains a concern, particularly in coastal and tribal communities that subsistence harvest shellfish known to contain low levels of the toxin. Domoic acid exposure via consumption of planktivorous fish also has a profound health impact on California sea lions (Zalophus californianus) affecting hundreds of animals yearly. Due to increasing algal toxin exposure threats globally, there is a critical need for reliable diagnostic tests for assessing chronic DA exposure in humans and wildlife. Here we report the discovery of a novel DA-specific antibody response that is a signature of chronic low-level exposure identified initially in a zebrafish exposure model and confirmed in naturally exposed wild sea lions. Additionally, we found that chronic exposure in zebrafish caused increased neurologic sensitivity to DA, revealing that repetitive exposure to DA well below the threshold for acute behavioral toxicity has underlying neurotoxic consequences. The discovery that chronic exposure to low levels of a small, water-soluble single amino acid triggers a detectable antibody response is surprising and has profound implications for the development of diagnostic tests for exposure to other pervasive environmental toxins.

  14. Radiation exposure of the public from operations of ranger uranium mines

    International Nuclear Information System (INIS)

    The radiological impact on the public from the biggest uranium mining and milling operation in Australia is assessed. The aerial pathway appears to be the critical pathway for transfer of radioactive contaminants (radionuclides of U chain) from the ranger site to the local population. It is suggested that juveniles of the permanent Aboriginal community of the Manaburduma camp in Jabiru (7km wnw of the mine site) are most likely to form the critical group of the local population. The per capita average annual effective dose equivalent rate to this group is 0,25±0,10 from inhalation of long-lived activity attached to dust particles and 0,04±0,03 mSv/y (4±3 mWLM/y) from exposure to radon daughters. No evidence was found for an increase of exposure of the public due to consumption of bush food collected in the vicinity of the ranger site. It is concluded that the possible radiation exposure of the public, which could be attributed to the Company's present operations is one to two orders of magnitude below the limits set by the present Australian radiation protection legislation and several times below the 1 mSv/y limit recommended by ICRP and foreshadowed in the presently revised Australian legislation. 10 refs., 3 tabs. (Author)

  15. Cost-effectiveness of protection actions to reduce occupational exposures in underground uranium mines

    International Nuclear Information System (INIS)

    The primary objective of this study is to present an analysis of protection actions against alpha energy due to short-lived Radon (Rn) daughters in an underground non sedimentary uranium mine. A set of combinations of simple protection (e.g. parpen wall isolating old stopes, increase in ventilation rates or installation of an electrostatic filter) options has been evaluated. The evaluation of the risk reduction options requires the knowledge of the effective dose equivalent (i.e. the indicator to express the risk) as a function of the considered options. For this purpose a mine model has to be defined, that will help modelling the alpha contamination due to short-lived Rn daughters. Finally a computer program has been established, that calculates the effective collective dose equivalent associated with the various protection options. Therefore, this study is able to point out the most 'cost-effective' options to reduce occupational exposure

  16. Ailing uranium millworkers seek recognition, aid

    International Nuclear Information System (INIS)

    Uranium millworkers who helped produce uranium for the U.S. nuclear defense program in the 1950's and 1960's are suing the federal government and uranium companies for compensation for illnesses that they believe are job-related. Symptoms of these illnesses include frequent blackouts, chronic bronchitis, asthma, constant fatigue, and susceptibility to colds. Research is being conducted to determine whether the millworkers' symptoms are due to excessive radiation exposure. Studies to date indicated that during the 1950's and early 1960's, radiation protection procedures at uranium milling facilities were extremely deficient

  17. Metabolism of uranium in the rat after inhalation of two industrial forms of ore concentrate: the implications for occupational exposure

    International Nuclear Information System (INIS)

    Aerosols produced from two commercially available ore concentrates in which the uranium was present essentially in the one as ammonium diuranate (ADU) and in the other as uranium octoxide (U3O8) were administered to rats. Uranium in the ADU bearing material was cleared rapidly from the lungs, the retention kinetics being similar to a class D (highly transportable) compound. Uranium in the U3O8 bearing material was removed from the lungs principally by mechanical processes, the retention kinetics being similar to a class Y (poorly transportable) compound. For both materials the distribution of uranium amongst body tissues and the fraction of the systemic content excreted in urine were similar to those obtained after the injection of soluble hexavalent compounds. For workers potentially exposed to both these materials, urine monitoring and lung radioactivity counting measurements should be used in addition to air sampling procedures for assessing the intake of uranium. Intakes of the ADU bearing material should be restricted to those permitted for short-term exposures on the basis of chemical toxicity, whereas those for the U3O8 bearing material should be governed by radiation dose. (author)

  18. Protective effects of quercetine on the neuronal injury in frontal cortex after chronic toluene exposure.

    Science.gov (United States)

    Kanter, Mehmet

    2013-08-01

    The aim of this study was designed to evaluate the possible protective effects of quercetine (QE) on the neuronal injury in the frontal cortex after chronic toluene exposure in rats. The rats were randomly allotted into one of the three experimental groups, namely, groups A (control), B (toluene treated) and C (toluene-treated with QE), where each group contains 10 animals. Control group received 1 ml of normal saline solution, and toluene treatment was performed by the inhalation of 3000 ppm toluene in an 8-h/day and 6-day/week order for 12 weeks. The rats in QE-treated group was given QE (15 mg/kg body weight) once a day intraperitoneally for 12 weeks, starting just after toluene exposure. Tissue samples were obtained for histopathological investigation. To date, no histopathological changes of neurodegeneration in the frontal cortex after chronic toluene exposure in rats by QE treatment have been reported. In this study, the morphology of neurons in the QE treatment group was well protected. Chronic toluene exposure caused severe degenerative changes, shrunken cytoplasm and extensively dark picnotic nuclei in neurons of the frontal cortex. We conclude that QE therapy causes morphologic improvement in neurodegeneration of frontal cortex after chronic toluene exposure in rats. We believe that further preclinical research into the utility of QE may indicate its usefulness as a potential treatment on neurodegeneration after chronic toluene exposure in rats. PMID:22252859

  19. Oral Methylphenidate Alleviates the Fine Motor Dysfunction Caused by Chronic Postnatal Manganese Exposure in Adult Rats

    OpenAIRE

    Beaudin, Stéphane A.; Strupp, Barbara J.; Lasley, Stephen M.; Fornal, Casimir A.; Mandal, Shyamali; Smith, Donald R

    2015-01-01

    Developmental manganese (Mn) exposure is associated with motor dysfunction in children and animal models, but little is known about the underlying neurochemical mechanisms or the potential for amelioration by pharmacotherapy. We investigated whether methylphenidate (MPH) alleviates fine motor dysfunction due to chronic postnatal Mn exposure, and whether Mn exposure impairs brain extracellular dopamine (DA) and norepinephrine (NE) in the prefrontal cortex (PFC) and striatum in adult animals. R...

  20. Miners' exposure to radon and its decay products in some Iranian non-uranium underground mines

    International Nuclear Information System (INIS)

    Measurements of radon, radon decay products and gamma exposure rate in 12 non-uranium underground mines have been carried out in order to estimate the occupational radiation exposure of miners. Continuous measurements of radon using pulse ionisation chambers and scintillation cell techniques were employed for these studies. Progenies of radon were collected on filter paper, and then a three-count procedure was used for the measurement. The equilibrium state between radon and its decay products has been determined. Concentrations of natural radionuclides (226Ra, 232Th and 40K) in ore and soil samples taken from various locations in each mine have been measured using a Canberra High Purity Germanium detector. Based on these measurements two ranges of dose were evident. Doses ranged from 0.1 to 1.52 mSv y-1 for nine mines and from 10 to 31 mSv y-1 for the other three mines. A separate grouping of the mines was recognised from radon concentrations, which varied from 2 Bq m-3 to 10 kBq m-3. In three of these mines, working level (WL) concentrations of the order of 36-1771 mWL were determined in different working areas. In all other mines, the concentrations were observed to be <45 mWL. (authors)

  1. Sub-chronic exposure to second hand smoke induces airspace leukocyte infiltration and decreases lung elastance

    Directory of Open Access Journals (Sweden)

    John M. Hartney

    2012-07-01

    Full Text Available Exposure to second hand tobacco smoke is associated with the development and/or exacerbation of several different pulmonary diseases in humans. To better understand the possible effects of second hand smoke exposure in humans, we sub-chronically (4 weeks exposed mice to a mixture of mainstream and sidestream tobacco smoke at concentrations similar to second hand smoke exposure in humans. The inflammatory response to smoke exposures was assessed at the end of this time by enumeration of pulmonary leukocyte infiltration together with measurements of lung elastance and pathology. This response was measured in both healthy wild type (C57BL/6 mice as well as mouse mutants deficient in the expression of Arhgef1 (Arhgef1–/– that display constitutive pulmonary inflammation and decreased lung elastance reminiscent of emphysema. The results from this study show that sub-chronic second hand smoke exposure leads to significantly increased numbers of airspace leukocytes in both healthy and mutant animals. While sub-chronic cigarette smoke exposure is not sufficient to induce changes in lung architecture as measured by mean linear intercept, both groups exhibit a significant decrease in lung elastance. Together these data demonstrate that even sub-chronic exposure to second hand smoke is sufficient to induce pulmonary inflammation and decrease lung elastance in both healthy and diseased animals and in the absence of tissue destruction.

  2. A review of exposures to radon, long-lived radionuclides and external gamma at the Czech uranium mine

    International Nuclear Information System (INIS)

    This paper presents the results of the personal exposure monitoring conducted in the Ron uranium mine in the Czech Republic. In this mine, which has been operated since the late 1950's, personal ALGADE dosemeters have been used since 1998. A group of 600 miners employed during the period 2000-09 has been analysed. Annual exposures to radon decay products, long-lived alpha emitters and external gamma radiation are described. These components play an essential role in the estimation of the total effective dose. The dependence of the exposures on the type of mining job is also assessed. (authors)

  3. A review of exposures to radon, long-lived radionuclides and external gamma at the Czech uranium mine.

    Science.gov (United States)

    Marušiaková, M; Gregor, Z; Tomášek, L

    2011-05-01

    This paper presents the results of the personal exposure monitoring conducted in the RoŽná uranium mine in the Czech Republic. In this mine, which has been operated since the late 1950s, personal ALGADE dosemeters have been used since 1998. A group of 600 miners employed during the period 2000-09 has been analysed. Annual exposures to radon decay products, long-lived alpha emitters and external gamma radiation are described. These components play an essential role in the estimation of the total effective dose. The dependence of the exposures on the type of mining job is also assessed. PMID:21471123

  4. Modelling the effects of ionizing radiation on survival of animal population: acute versus chronic exposure.

    Science.gov (United States)

    Kryshev, A I; Sazykina, T G

    2015-03-01

    The objective of the present paper was application of a model, which was originally developed to simulate chronic ionizing radiation effects in a generic isolated population, to the case of acute exposure, and comparison of the dynamic features of radiation effects on the population survival in cases of acute and chronic exposure. Two modes of exposure were considered: acute exposure (2-35 Gy) and chronic lifetime exposure with the same integrated dose. Calculations were made for a generic mice population; however, the model can be applied for other animals with proper selection of parameter values. In case of acute exposure, in the range 2-11 Gy, the population response was in two phases. During a first phase, there was a depletion in population survival; the second phase was a recovery period due to reparation of damage and biosynthesis of new biomass. Model predictions indicate that a generic mice population, living in ideal conditions, has the potential for recovery (within a mouse lifetime period) from acute exposure with dose up to 10-11 Gy, i.e., the population may recover from doses above an LD50 (6.2 Gy). Following acute doses above 14 Gy, however, the mice population went to extinction without recovery. In contrast, under chronic lifetime exposures (500 days), radiation had little effect on population survival up to integrated doses of 14-15 Gy, so the survival of a population subjected to chronic exposure was much better compared with that after an acute exposure with the same dose. Due to the effect of "wasted radiation", the integrated dose of chronic exposure could be about two times higher than acute dose, producing the same effect on survival. It is concluded that the developed generic population model including the repair of radiation damage can be applied both to acute and chronic modes of exposure; results of calculations for generic mice population are in qualitative agreement with published data on radiation effects in mice. PMID

  5. In vivo effects of a chronic contamination by uranium or cesium 137 on the pharmaceutical metabolism, of the vitamin D and cholesterol; Effets in vivo d'une contamination chronique par l'uranium ou le cesium 137 sur le metabolisme du medicament, de la vitamine D et du cholesterol

    Energy Technology Data Exchange (ETDEWEB)

    Souidi, M

    2006-11-15

    In conclusion, an animal model, miming the chronic contamination of the populations exposed to the uranium, was used for the first time to show that the chronic ingestion of a weak dose of depleted uranium can affect the level of active vitamin D without modifying the mineral homeostasis. This study shows that this radionuclide can lead molecular modifications of the CYPs and the nuclear receivers involved in the metabolism of the vitamin D not only at the level of the liver and kidney but also at the level of the independent metabolism in the brain. The deficiency in vitamin D can provoke osseous diseases such as the rickets at the child and the osteomalacia at the adult. The three categories of population the most exposed to this deficiency are the infants, the pregnant women and the old persons. Strong prevalence of the vitamin D deficiency associated with a chronic exposure to uranium could lead to osseous disorders. To verify this hypothesis, it will be necessary secondly to realize this study on individuals animal models predisposed to the rickets or to the osteomalacia. (N.C.)

  6. Occupational diseases in uranium and ore miners, related to the radiation exposure in Czech Republic, in 2003-2013

    International Nuclear Information System (INIS)

    Dozens cases of disease of former or present uranium and ore miners are submitted to judgment as occupational diseases every year in the Czech Republic. Patients or attending physicians suggest that these cases are caused by occupational ionizing radiation. Only a part of these cases is qualified as occupational disease. The term 'occupational disease' is rather juridical term which underlies the right to financial compensation. The causal association with exposure to ionizing radiation cannot be indisputably verified by expert medical opinion. Most diseases in uranium and ore miners, which are proposed as occupational disease, are malignant tumors. The majority of judged cases are lung cancers from radioactive agents. The lecture gives general information about all judged cases of occupational diseases in former uranium and ore miners in the Czech Republic in the years 2002 - 2013. In the period 2002-13 were 40-80 cases submitted to judgment as potential occupational disease every year. (authors)

  7. Uranium mining sites - Thematic sheets

    International Nuclear Information System (INIS)

    A first sheet proposes comments, data and key numbers about uranium extraction in France: general overview of uranium mining sites, status of waste rock and tailings after exploitation, site rehabilitation. The second sheet addresses the sources of exposure to ionizing radiations due to ancient uranium mining sites: discussion on the identification of these sources associated with these sites, properly due to mining activities or to tailings, or due to the transfer of radioactive substances towards water and to the contamination of sediments, description of the practice and assessment of radiological control of mining sites. A third sheet addresses the radiological exposure of public to waste rocks, and the dose assessment according to exposure scenarios: main exposure ways to be considered, studied exposure scenarios (passage on backfilled path and grounds, stay in buildings built on waste rocks, keeping mineralogical samples at home). The fourth sheet addresses research programmes of the IRSN on uranium and radon: epidemiological studies (performed on mine workers; on French and on European cohorts, French and European studies on the risk of lung cancer associated with radon in housing), study of the biological effects of chronic exposures. The last sheet addresses studies and expertises performed by the IRSN on ancient uranium mining sites in France: studies commissioned by public authorities, radioactivity control studies performed by the IRSN about mining sites, participation of the IRSN to actions to promote openness to civil society

  8. Impacts of chronic low-level nicotine exposure on Caenorhabditis elegans reproduction: Identification of novel gene targets

    OpenAIRE

    Michael A Smith; Zhang, Yanqiong; Polli, Joseph R.; Wu, Hongmei; Zhang, Baohong; Xiao, Peng; Farwell, Mary A.; Pan, Xiaoping

    2013-01-01

    Effects and mechanisms of chronic exposure to low levels of nicotine is an area fundamentally important however less investigated. We employed the model organism Caenorhabditis elegans to investigate potential impacts of chronic (24 h) and low nicotine exposure (6.17–194.5 μM) on stimulus-response, reproduction, and gene expressions. Nicotine significantly affects the organism's response to touch stimulus (p = 0.031), which follows a dose-dependent pattern. Chronic nicotine exposure promotes ...

  9. Assessment of the solubility of thorium and uranium from black sand of Camargue in both simulated lung and gut fluids for dose calculation after internal exposure

    Energy Technology Data Exchange (ETDEWEB)

    Frelon, S.; Chazel, V.; Tourlonias, E.; Paquet, F. [IRSN/ DRPH/ SRBE, LRTOX, BP 166, 26702 Pierrelatte Cedex (France); Blanchardon, E. [IRSN/ DRPH/ SDI, LEDI, BP 17, 92262 Fontenay Aux Roses Cedex (France); Bouisset, P. [IRSN/ DEI/ STEME, LMRE, Bois des rames, 91400 Orsay (France); Pourcelot, L. [IRSN/ DEI/ SESURE, LERCM, BP3, 13 115 St Paul lez Durance Cedex (France)

    2006-07-01

    In the south of France, some beaches of Camargue present a high rate of natural radioactivity due to thorium and uranium from zircon and apatite heavy minerals present in the so-called black sand. These radionuclides may lead to internal exposure consecutive to inhalation or ingestion of this sand. The accurate assessment of radiological risk after internal exposure of public frequenting these beaches requires some information on the human bioavailability of U and Th from the sand. Both routes of intake were studied in this work and the consecutive dose delivered was calculated under two different scenarios for each type of exposure. As far as inhalation is concerned, the first important conclusion is that the inhalable fraction, i.e. particles with aerodynamic diameters below 50 {mu}m, was tiny (0.002%) in this sample of sand. Moreover in vitro assays of solubility were performed for this fraction and showed that U and Th as well as their progeny presented moderate solubility. Then effective doses under several scenarios were calculated and seem to demonstrate a very poor risk of exposure after inhalation. Indeed, a dose of 1 mSv would be received by a babies after inhalation of about 40 Kg of sand, that is impossible, whereas a more realistic scenario of chronic exposure only reached 31 {mu} Sv. In case of ingestion, the solubility of Th and U in the gastrointestinal fluids was found to be very low with a maximum solubility of 0.5% of the initial mass of radioelement in the sample of sand. Then the worst hypothesis studied yields an effective dose of 0.018 mSv./(g-swallowed sand) that is roughly 50 times less than the legal annual dose limit for members of the public. as a conclusion, the possible internal dose after exposure by inhalation or ingestion of black sand of Camargue seems to be very low under the conditions of this study. (N.C.)

  10. Assessment of the solubility of thorium and uranium from black sand of Camargue in both simulated lung and gut fluids for dose calculation after internal exposure

    International Nuclear Information System (INIS)

    In the south of France, some beaches of Camargue present a high rate of natural radioactivity due to thorium and uranium from zircon and apatite heavy minerals present in the so-called black sand. These radionuclides may lead to internal exposure consecutive to inhalation or ingestion of this sand. The accurate assessment of radiological risk after internal exposure of public frequenting these beaches requires some information on the human bioavailability of U and Th from the sand. Both routes of intake were studied in this work and the consecutive dose delivered was calculated under two different scenarios for each type of exposure. As far as inhalation is concerned, the first important conclusion is that the inhalable fraction, i.e. particles with aerodynamic diameters below 50 μm, was tiny (0.002%) in this sample of sand. Moreover in vitro assays of solubility were performed for this fraction and showed that U and Th as well as their progeny presented moderate solubility. Then effective doses under several scenarios were calculated and seem to demonstrate a very poor risk of exposure after inhalation. Indeed, a dose of 1 mSv would be received by a babies after inhalation of about 40 Kg of sand, that is impossible, whereas a more realistic scenario of chronic exposure only reached 31 μ Sv. In case of ingestion, the solubility of Th and U in the gastrointestinal fluids was found to be very low with a maximum solubility of 0.5% of the initial mass of radioelement in the sample of sand. Then the worst hypothesis studied yields an effective dose of 0.018 mSv./(g-swallowed sand) that is roughly 50 times less than the legal annual dose limit for members of the public. as a conclusion, the possible internal dose after exposure by inhalation or ingestion of black sand of Camargue seems to be very low under the conditions of this study. (N.C.)

  11. Ionizing radiation exposures in treatments of solid neoplasms are not associated with subsequent increased risks of chronic lymphocytic leukemia.

    Science.gov (United States)

    Radivoyevitch, Tomas; Sachs, Rainer K; Gale, Robert Peter; Smith, Mitchell R; Hill, Brian T

    2016-04-01

    Exposure to ionizing radiation is not thought to cause chronic lymphocytic leukemia (CLL). Challenging this notion are recent data suggesting CLL incidence may be increased by radiation exposure from the atomic bombs (after many decades), uranium mining and nuclear power facility accidents. To assess the effects of therapeutic ionizing radiation for the treatment of solid neoplasms we studied CLL risks in data from the Surveillance, Epidemiology, and End Results (SEER) Program. Specifically, we compared the risks of developing CLL in persons with a 1(st) non-hematologic cancer treated with or without ionizing radiation. We controlled for early detection effects on CLL risk induced by surveillance after 1(st) cancer diagnoses by forming all-time cumulative CLL relative risks (RR). We estimate such CLL RR to be 1.20 (95% confidence interval, 1.17, 1.23) for persons whose 1(st) cancer was not treated with ionizing radiation and 1.00 (0.96, 1.05) for persons whose 1(st) cancer was treated with ionizing radiations. These results imply that diagnosis of a solid neoplasm is associated with an increased risk of developing CLL only in persons whose 1(st) cancer was not treated with radiation therapy. PMID:26922774

  12. Determination of internal exposure doses of the personnel of uranium-mining company due to radon isotopes decay products

    International Nuclear Information System (INIS)

    This work carries out a determination of individual doses of internal exposure of the staff of the uranium-mining company in Kazakhstan due to radon decay products. The company extracts uranium by in-situ leaching. After leaching, uranium is sorbed from a solution in facilities where the staff is located. The state of three uranium mines was analyzed. The dose determination was conducted in tune with the proposed method by using integral alpha-tracking detectors to identify the content of 222Rn and express appliances to identify the content of radio-active aerosols in air of the working area for determination the equilibrium coefficient. The measurements were performed within one year. The work produced the results in average annual values of radon and thoron decay products activity concentration and variation, equilibrium coefficient variation, and so-called expressive-to-integral value conversion factor. The obtained personnel's individual radiation doses due to radon exposure for this period lie within the range of < 1 mSv/year. (author)

  13. 38 CFR 3.316 - Claims based on chronic effects of exposure to mustard gas and Lewisite.

    Science.gov (United States)

    2010-07-01

    ..., bronchitis, emphysema, asthma or chronic obstructive pulmonary disease. (3) Full-body exposure to nitrogen mustard during active military service together with the subsequent development of acute...

  14. Chronic Nicotine Exposure Attenuates Methamphetamine-Induced Dopaminergic Deficits.

    Science.gov (United States)

    Vieira-Brock, Paula L; McFadden, Lisa M; Nielsen, Shannon M; Ellis, Jonathan D; Walters, Elliot T; Stout, Kristen A; McIntosh, J Michael; Wilkins, Diana G; Hanson, Glen R; Fleckenstein, Annette E

    2015-12-01

    Repeated methamphetamine (METH) administrations cause persistent dopaminergic deficits resembling aspects of Parkinson's disease. Many METH abusers smoke cigarettes and thus self-administer nicotine; yet few studies have investigated the effects of nicotine on METH-induced dopaminergic deficits. This interaction is of interest because preclinical studies demonstrate that nicotine can be neuroprotective, perhaps owing to effects involving α4β2 and α6β2 nicotinic acetylcholine receptors (nAChRs). This study revealed that oral nicotine exposure beginning in adolescence [postnatal day (PND) 40] through adulthood [PND 96] attenuated METH-induced striatal dopaminergic deficits when METH was administered at PND 89. This protection did not appear to be due to nicotine-induced alterations in METH pharmacokinetics. Short-term (i.e., 21-day) high-dose nicotine exposure also protected when administered from PND 40 to PND 61 (with METH at PND 54), but this protective effect did not persist. Short-term (i.e., 21-day) high-dose nicotine exposure did not protect when administered postadolescence (i.e., beginning at PND 61, with METH at PND 75). However, protection was engendered if the duration of nicotine exposure was extended to 39 days (with METH at PND 93). Autoradiographic analysis revealed that nicotine increased striatal α4β2 expression, as assessed using [(125)I]epibatidine. Both METH and nicotine decreased striatal α6β2 expression, as assessed using [(125)I]α-conotoxin MII. These findings indicate that nicotine protects against METH-induced striatal dopaminergic deficits, perhaps by affecting α4β2 and/or α6β2 expression, and that both age of onset and duration of nicotine exposure affect this protection. PMID:26391161

  15. Particulate matter air pollution exposure: role in the development and exacerbation of chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Sean H Ling

    2009-06-01

    Full Text Available Sean H Ling, Stephan F van EedenJames Hogg iCAPTURE Centre for Pulmonary and Cardiovascular Research and Heart and Lung Institute, University of British Columbia, Vancouver, British Columbia, CanadaAbstract: Due to the rapid urbanization of the world population, a better understanding of the detrimental effects of exposure to urban air pollution on chronic lung disease is necessary. Strong epidemiological evidence suggests that exposure to particulate matter (PM air pollution causes exacerbations of pre-existing lung conditions, such as, chronic obstructive pulmonary disease (COPD resulting in increased morbidity and mortality. However, little is known whether a chronic, low-grade exposure to ambient PM can cause the development and progression of COPD. The deposition of PM in the respiratory tract depends predominantly on the size of the particles, with larger particles deposited in the upper and larger airways and smaller particles penetrating deep into the alveolar spaces. Ineffective clearance of this PM from the airways could cause particle retention in lung tissues, resulting in a chronic, low-grade inflammatory response that may be pathogenetically important in both the exacerbation, as well as, the progression of lung disease. This review focuses on the adverse effects of exposure to ambient PM air pollution on the exacerbation, progression, and development of COPD.Keywords: chronic obstructive pulmonary disease, particulate matter, air pollution, alveolar macrophage

  16. Chronic ethanol exposure inhibits distraction osteogenesis in a mouse model: Role of the TNF signaling axis

    International Nuclear Information System (INIS)

    Tumor necrosis factor-alpha (TNF-α) is an inflammatory cytokine that modulates osteoblastogenesis. In addition, the demonstrated inhibitory effects of chronic ethanol exposure on direct bone formation in rats are hypothetically mediated by TNF-α signaling. The effects in mice are unreported. Therefore, we hypothesized that in mice (1) administration of a soluble TNF receptor 1 derivative (sTNF-R1) would protect direct bone formation during chronic ethanol exposure, and (2) administration of recombinant mouse TNF-α (rmTNF-α) to ethanol naive mice would inhibit direct bone formation. We utilized a unique model of limb lengthening (distraction osteogenesis, DO) combined with liquid diets to measure chronic ethanol's effects on direct bone formation. Chronic ethanol exposure resulted in increased marrow TNF, IL-1, and CYP 2E1 RNA levels in ethanol-treated vs. control mice, while no significant weight differences were noted. Systemic administration of sTNF-R1 during DO (8.0 mg/kg/2 days) to chronic ethanol-exposed mice resulted in enhanced direct bone formation as measured radiologically and histologically. Systemic rmTNF-α (10 μg/kg/day) administration decreased direct bone formation measures, while no significant weight differences were noted. We conclude that chronic ethanol-associated inhibition of direct bone formation is mediated to a significant extent by the TNF signaling axis in a mouse model

  17. Influence of chronic x-ray exposure on adrenal glucocorticoid function and adrenocorticocyte membrane potential

    International Nuclear Information System (INIS)

    The peculiarities of adrenal glucocorticoid function and membrane potential (MP) of zona fasciculata adrenocorticocyte (ACC) in rats after chronic x-ray exposure was studied. The changes of adrenal glucocorticoid function caused by chronic x-ray exposure within a relatively small period of irradiation (1.5 months) are obscure and manifest themselves only at physiological load. With the prolongation of the period (8 and 15 months), more considerable inhibition of the adrenal glucocorticoid function and disturbances in the membrane mechanisms of ACC MP level regulation are revealed

  18. Cytogenetic studies in workers with chronic occupational radiation exposure

    International Nuclear Information System (INIS)

    The technique of chromosomal aberration detection on peripheral lymphocytes blood samples from monazite industry workers was used to study the cytogenetic effect of low chronic radiation doses. Cells from 51 workers and 21 controls were analysed. Cytogenetic data from individuals from different working areas were statistically compared among themselves and with the control group. The possible correlations between chromosomal aberration frequencies and cumulative external dose and working time were investigated. The influence of smoking was also tested. The link to the wives spontaneous abortions was analysed. Our results indicate possible biological effects on this sample of workers. (author)

  19. Renal effects of uranium in drinking water.

    OpenAIRE

    Kurttio, Päivi; Auvinen, Anssi; Salonen, Laina; Saha, Heikki; Pekkanen, Juha; Mäkeläinen, Ilona; Väisänen, Sari B; Penttilä, Ilkka M; Komulainen, Hannu

    2002-01-01

    Animal studies and small studies in humans have shown that uranium is nephrotoxic. However, more information about its renal effects in humans following chronic exposure through drinking water is required. We measured uranium concentrations in drinking water and urine in 325 persons who had used drilled wells for drinking water. We measured urine and serum concentrations of calcium, phosphate, glucose, albumin, creatinine, and beta-2-microglobulin to evaluate possible renal effects. The media...

  20. The effect of exposure to employees from mining and milling operations in a uranium mine on lead isotopes-a pilot study

    International Nuclear Information System (INIS)

    Potential exposure during mining and milling of uranium ore has resulted in the industry being highly regulated. Exposure can arise from inhalation of the daughter product radioactive gas radon (222Rn), inhalation of radioactive dust particles from mining and milling, direct irradiation from outside the body, and ingestion of radionuclides (e.g. uranium or radium) in food or water. Making use of the highly unusual lead isotopic signature for uranium ores (high 206Pb/204Pb from the high uranium content, low 208Pb/204Pb from the low Th/U ratio), we undertook a pilot study of nine male mine employees and three controls from the Ranger uranium mine in the Northern Territory Australia to determine if it was feasible to use lead isotopes in blood to identify exposure to uranium-derived materials. The lead isotopic data for the mine employees and controls plot in two distinct fields which are consistent with predicted isotopic patterns. Assuming retention of 10% of the ingested lead, then the increases seen in 206Pb represent intakes of between 0.9 and 15 mg, integrated over the years of exposure. The small amount of lead does not affect blood lead concentrations, but appears to be sufficient to be detectable with sensitive isotopic methods. Further studies, including those on urine, should be undertaken to confirm the veracity of the lead isotope method in monitoring exposure of uranium industry employees

  1. Effects of prenatal exposure to chronic mild stress and toluene in rats

    DEFF Research Database (Denmark)

    Hougaard, Karin; Andersen, Maibritt B; Hansen, Ase M;

    2005-01-01

    The aim of the present study was to elucidate whether prenatal chronic stress, in combination with exposure to a developmental neurotoxicant, would increase effects in the offspring compared with the effects of either exposure alone. Development and neurobehavioral effects were investigated in...... female offspring of pregnant rats (Mol:WIST) exposed to chronic mild stress (CMS) during gestational days (GD) 9-20, or 1500 ppm toluene, 6 h/day during gestational days 7-20, or a combination of the two. Prenatal CMS was associated with decreased thymic weight and increased auditory startle response....... The corticosterone response to restraint seemed modified by prenatal exposure to toluene. Lactational body weight was decreased in offsprings subjected to CMS, primarily due to effects in the combined exposure group. Cognitive function was investigated in the Morris water maze, and some indications of...

  2. Segmental hair testing to disclose chronic exposure to psychoactive drugs.

    Science.gov (United States)

    Marchei, Emilia; Palmi, Ilaria; Pichini, Simona; Pacifici, Roberta; Anton Airaldi, Ileana-Rita; Costa Orvay, Juan Antonio; García Serra, Joan; Bonet Serra, Bartolomé; García-Algar, Óscar

    2016-01-01

    This study presents the case of a 4-year-old healthy child admitted to the paediatric ward for suspected accidental intoxication due to ingestion of narcoleptic drugs (methylphenidate, sertraline and quetiapine), taken on a regular basis by his 8-year-old brother affected by Asperger syndrome.Intoxication can be objectively assessed by measurements of drugs and metabolites in biological matrices with short-term (blood and urine) or long-term (hair) detection windows. At the hospital, the child's blood and urine were analysed by immunoassay (confirmed by liquid chromatography-mass spectrometry), and sertraline and quetiapine and their metabolites were identified. The suspicion that the mother administered drugs chronically prompted the analysis of six, consecutive 2-cm segments of the child's hair, using ultra-high performance liquid chromatography-tandem mass spectrometry, thereby accounting for ingestion over the previous 12 months. Quetiapine was found in the first four segments with a mean concentration of 1.00 ng/mg ± 0.94 ng/mg hair while sertraline and its metabolite, desmethyl-sertraline, were found in all segments with a mean concentration of 2.65 ± 0.94 ng/mg and 1.50 ± 0.94 ng/mg hair, respectively. Hair analyses were negative for methylphenidate and its metabolite (ritalinic acid). Biological matrices testing for psychoactive drugs disclosed both acute and chronic intoxication with quetiapine and sertraline administered by the mother. PMID:27399225

  3. Impairment induced by chronic occupational cadmium exposure during brazing process

    International Nuclear Information System (INIS)

    Cadmium (CD) is considered a metal of the 20th century to which all inhabitants of develop societies are exposed. Long-term occupational and environmental exposure to CD often results in renal dysfunction as the kidney is considered the critical target organ. The aim of this work was to evalutate both resporatory and renal manifestations induced by occupational exposure to CD compounds during brazing process, and suggesting a protocol for prevention and control for CD- induced health effects. This study was conducted on 20 males occupationally exposed workers. They are divided into two groups: Group-1 included (10) exposed smokers and group-2 included (10) exposed non-smokers. Results of both groups were compared with those of 10 healthy age and sex matched non-smokers. All subjects were subjected to detailed history taking and laboratory investigations including blood and urinary CD, liver profile (SGOT, SGPT and alkline phosphates), kindey function tests (blood urea, creatinine and urinary beta2- microglobulin). The level of Cd in the atmosphere of the work plase air was also assessed to detect the degree of exposure as it was about 6 times greater than thesave level (1 mu /m3).(1) This study demonstrated elevation levels of blood CD, urea, creatinine and urinary CD and beta2 -microglobulin for both exposed worker groups than the controls. In additions no appreciable were noted for liver function tests, although the levels fell within normal range

  4. Assessment of exposure of uranium miners to radon progeny using in vivo measurement of 210Pb in bone

    International Nuclear Information System (INIS)

    Epidemiological studies of lung cancer incidence among uranium miners from various populations around the world have shown a significant variability in the relative risk per unit exposure - a range of a factor of 30. A significant fraction of the uncertainty associated with these risk coefficients may be due to differences in the methods and quality of data used in calculating cumulative exposures, in Working Level Months (WLM), for the various miner populations. We hypothesize that in vivo measurement of 210Pb, a long-lived radon decay product, retained in bone will provide a better measure of the exposure of individual miners to radon and progeny during their mining careers. To accomplish these in vivo measurements, the Lovelace Respiratory Research Institute (LRRI) In Vivo Bioassay Facility (IVBF) was modified to optimize a counting geometry for measuring 210Pb in the skull. Six phoswich detectors (12.7 cm diameter) were positioned about the head of a reclining subject (one posterior, one anterior, and four on the sides of the head), and photon emission from the skull was measured using anticoincidence multichannel analysis electronics. To date, we have analyzed the in vivo measurement data from about 90 former uranium miners from the Grants, New Mexico (NM), mining district. The recorded WLM exposures for each uranium miner (data from the UNM epidemiological data base) were compared with a WLM exposure calculated using a Pb biokinetic model coupled to the ICRP Publication 66 respiratory tract dosimetry model. The analyses show that the independent measures of exposure are statistically correlated but vary greatly among individual values. (author)

  5. Chronic obstructive pulmonary disease and long-term exposure to traffic-related air pollution: a cohort study

    DEFF Research Database (Denmark)

    Andersen, Zorana J; Hvidberg, Martin; Jensen, Steen S; Ketzel, Matthias; Loft, Steffen; Sørensen, Mette; Tjønneland, Anne; Overvad, Kim; Raaschou-Nielsen, Ole

    2011-01-01

    Short-term exposure to air pollution has been associated with exacerbation of chronic obstructive pulmonary disease (COPD), whereas the role of long-term exposures on the development of COPD is not yet fully understood.......Short-term exposure to air pollution has been associated with exacerbation of chronic obstructive pulmonary disease (COPD), whereas the role of long-term exposures on the development of COPD is not yet fully understood....

  6. Chronic oral exposure to the aldehyde pollutant acrolein induces dilated cardiomyopathy

    OpenAIRE

    Ismahil, Mohamed Ameen; Hamid, Tariq; Haberzettl, Petra; Gu, Yan; Chandrasekar, Bysani; Srivastava, Sanjay; Bhatnagar, Aruni; Prabhu, Sumanth D.

    2011-01-01

    Environmental triggers of dilated cardiomyopathy are poorly understood. Acute exposure to acrolein, a ubiquitous aldehyde pollutant, impairs cardiac function and cardioprotective responses in mice. Here, we tested the hypothesis that chronic oral exposure to acrolein induces inflammation and cardiomyopathy. C57BL/6 mice were gavage-fed acrolein (1 mg/kg) or water (vehicle) daily for 48 days. The dose was chosen based on estimates of human daily unsaturated aldehyde consumption. Compared with ...

  7. Controlled exposure of volunteers with chronic obstructive pulmonary disease to sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Linn, W.S.; Fischer, D.A.; Shamoo, D.A.; Spier, C.E.; Valencia, L.M.; Anzar, U.T.; Hackney, J.D.

    1985-08-01

    Twenty-four volunteers with chronic obstructive pulmonary disease (COPD) were exposed to sulfur dioxide (SO/sub 2/) at 0, 0.4, and 0.8 ppm in an environmental control chamber. Exposures lasted 1 hr and included two 15-min exercise periods (mean exercise ventilation rate 18 liter/min). Pulmonary mechanical function was evaluated before exposures, after initial exercise, and at the end of exposure. Blood oxygenation was measured by ear oximetry before exposure and during the second exercise period. Symptoms were recorded throughout exposure periods and for 1 week afterward. No statistically significant changes in physiology or symptoms could be attributed to SO/sub 2/ exposure. Older adults with COPD seem less reactive to a given concentration of SO/sub 2/ than heavily exercising young adult asthmatics. This may be due to lower ventilation rates (i.e., lower SO/sub 2/ dose rates) and/or to lower airway reactivity in the COPD group.

  8. Induction of vascular remodeling in the lung by chronic house dust mite exposure.

    Science.gov (United States)

    Rydell-Törmänen, Kristina; Johnson, Jill R; Fattouh, Ramzi; Jordana, Manel; Erjefält, Jonas S

    2008-07-01

    Structural changes to the lung are associated with chronic asthma. In addition to alterations to the airway wall, asthma is associated with vascular modifications, although this aspect of remodeling is poorly understood. We sought to evaluate the character and kinetics of vascular remodeling in response to chronic aeroallergen exposure. Because many ovalbumin-driven models used to investigate allergic airway disease do so in the absence of persistent airway inflammation, we used a protocol of chronic respiratory exposure to house dust mite extract (HDME), which has been shown to induce persistent airway inflammation consistent with that seen in humans with asthma. Mice were exposed to HDME intranasally for 7 or 20 consecutive weeks, and resolution of the inflammatory and remodeling response to allergen was investigated 4 weeks after the end of a 7-week exposure protocol. Measures of vascular remodeling, including total collagen deposition, procollagen I production, endothelial and smooth muscle cell proliferation, smooth muscle area, and presence of myofibroblasts, were investigated histologically in lung vessels of different sizes and locations. We observed an increase in total collagen content, which did not resolve upon cessation of allergen exposure. Other parameters were significantly increased after 7 and/or 20 weeks of allergen exposure but returned to baseline after allergen withdrawal. We conclude that respiratory HDME exposure induces airway remodeling and pulmonary vascular remodeling, and, in accordance with airway remodeling, some components of these structural changes may be irreversible. PMID:18314535

  9. Lifetime environmental tobacco smoke exposure and the risk of chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Balmes John

    2005-05-01

    Full Text Available Abstract Background Exposure to environmental tobacco smoke (ETS, which contains potent respiratory irritants, may lead to chronic airway inflammation and obstruction. Although ETS exposure appears to cause asthma in children and adults, its role in causing COPD has received limited attention in epidemiologic studies. Methods Using data from a population-based sample of 2,113 U.S. adults aged 55 to 75 years, we examined the association between lifetime ETS exposure and the risk of developing COPD. Participants were recruited from all 48 contiguous U.S. states by random digit dialing. Lifetime ETS exposure was ascertained by structured telephone interview. We used a standard epidemiologic approach to define COPD based on a self-reported physician diagnosis of chronic bronchitis, emphysema, or COPD. Results Higher cumulative lifetime home and work exposure were associated with a greater risk of COPD. The highest quartile of lifetime home ETS exposure was associated with a greater risk of COPD, controlling for age, sex, race, personal smoking history, educational attainment, marital status, and occupational exposure to vapors, gas, dusts, or fumes during the longest held job (OR 1.55; 95% CI 1.09 to 2.21. The highest quartile of lifetime workplace ETS exposure was also related to a greater risk of COPD (OR 1.36; 95% CI 1.002 to 1.84. The population attributable fraction was 11% for the highest quartile of home ETS exposure and 7% for work exposure. Conclusion ETS exposure may be an important cause of COPD. Consequently, public policies aimed at preventing public smoking may reduce the burden of COPD-related death and disability, both by reducing direct smoking and ETS exposure.

  10. Chronic ethanol exposure enhances the aggressiveness of breast cancer: the role of p38γ.

    Science.gov (United States)

    Xu, Mei; Wang, Siying; Ren, Zhenhua; Frank, Jacqueline A; Yang, Xiuwei H; Zhang, Zhuo; Ke, Zun-Ji; Shi, Xianglin; Luo, Jia

    2016-01-19

    Both epidemiological and experimental studies suggest that ethanol may enhance aggressiveness of breast cancer. We have previously demonstrated that short term exposure to ethanol (12-48 hours) increased migration/invasion in breast cancer cells overexpressing ErbB2, but not in breast cancer cells with low expression of ErbB2, such as MCF7, BT20 and T47D breast cancer cells. In this study, we showed that chronic ethanol exposure transformed breast cancer cells that were not responsive to short term ethanol treatment to a more aggressive phenotype. Chronic ethanol exposure (10 days - 2 months) at 100 (22 mM) or 200 mg/dl (44 mM) caused the scattering of MCF7, BT20 and T47D cell colonies in a 3-dimension culture system. Chronic ethanol exposure also increased colony formation in an anchorage-independent condition and stimulated cell invasion/migration. Chronic ethanol exposure increased cancer stem-like cell (CSC) population by more than 20 folds. Breast cancer cells exposed to ethanol in vitro displayed a much higher growth rate and metastasis in mice. Ethanol selectively activated p38γ MAPK and RhoC but not p38α/β in a concentration-dependent manner. SP-MCF7 cells, a derivative of MCF7 cells which compose mainly CSC expressed high levels of phosphorylated p38γ MAPK. Knocking-down p38γ MAPK blocked ethanol-induced RhoC activation, cell scattering, invasion/migration and ethanol-increased CSC population. Furthermore, knocking-down p38γ MAPK mitigated ethanol-induced tumor growth and metastasis in mice. These results suggest that chronic ethanol exposure can enhance the aggressiveness of breast cancer by activating p38γ MAPK/RhoC pathway. PMID:26655092

  11. A review of gamma doses and radon daughter exposures for workers in some Canadian uranium mines from 1984 to 1987

    International Nuclear Information System (INIS)

    In the light of the 1977 recommendations of the International Commission on Radiological Protection (ICRP 26), the Atomic Energy Control Board (AECB) proposes to amend the Atomic Energy Control (AEC) Regulations. The most basic change from the current Regulations is the introduction of the concept of effective dose equivalent. In order to explore some possible implications of the Proposal General Amendments to the Atomic Energy Control Regulations (PGAAEC), the doses and exposures of some Canadian uranium mine workers during the period 1984 to 1987 are analysed. As a basis for comparison, the distributions of annual gamma doses and radon daughter exposures for the entire worker population and for different job categories as percentages of the Maximum Permissible Dose and Exposure in the current AEC Regulations are presented. Job categories of high exposures and doses are identified. (author)

  12. Graded exposure for chronic low back pain in older adults : a pilot study

    NARCIS (Netherlands)

    Leonhardt, Corinna; Kuss, Katrin; Becker, Annette; Basler, Heinz-Dieter; de jong, Jeroen; Flatau, Brigitta; Laekeman, Marjan; Mattenklodt, Peter; Schuler, Matthias; Vlaeyen, Johan; Quint, Sabine

    2016-01-01

    BACKGROUND AND PURPOSE: Fear-avoidance beliefs in older adults with chronic low back pain (CLBP) can lead to disability. Graded exposure-based active physical therapy could be an option to enhance physical ability in older patients with CLBP. The purpose of this study was to develop a standardized g

  13. Lung functions at school age and chronic exposure to outdoor and indoor air pollution

    Energy Technology Data Exchange (ETDEWEB)

    Neuberger, M.; Kundi, M.; Wiesenberger, W. [Vienna Univ. (Austria). Dept. of Preventive Medicine

    1995-12-31

    Early signs of lung function impairment have been found correlated with annual concentrations of outdoor air pollutants and with passive smoking. To investigate the combined effects of both indicators of chronic exposure to air pollution pulmonary functions in all elementary and high school children of an Austrian town was examined for 5 years. (author)

  14. THERMOREGULATION IN THE RAT DURING CHRONIC, DIETARY EXPOSURE TO CHLORPYRIFOS, AN ORGANOPHOSPHATE INSECTICIDE.

    Science.gov (United States)

    Administration of chlorpyrifos (CHP) at a dose of 25 to 80 mg/kg (p.o.) To rats results in hypothermia followed by a fever lasting for several days. To understand if chronic, low level exposure to CHP affects thermoregulation in a comparable manner to acute administration, male L...

  15. Prolonged Exposure Treatment of Chronic PTSD in Juvenile Sex Offenders: Promising Results from Two Case Studies

    Science.gov (United States)

    Hunter, John A.

    2010-01-01

    Prolonged exposure (PE) was used to treat chronic PTSD secondary to severe developmental trauma in two adolescent male sex offenders referred for residential sex offender treatment. Both youth were treatment resistant prior to initiation of PE and showed evidence of long-standing irritability and depression/anxiety. Clinical observation and…

  16. SOME EFFECTS OF CHRONIC TRITIUM EXPOSURE DURING SELECTED AGES IN THE RAT

    Science.gov (United States)

    To assess the implication of age at the time of exposure to chronic irradiation, rats were exposed to constant tritium (HTO) activities of 10 microcuries/ml of body water for 42 days beginning either on the first day of pregnancy or at birth, or at 42 days or 74 days of age. This...

  17. RESPONSES OF SUBJECTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE AFTER EXPOSURES TO 0.3 PPM OZONE

    Science.gov (United States)

    The authors previously reported (1982) that the respiratory mechanics of intermittently exercising persons with chronic obstructive pulmonary disease (COPD) were unaffected by a 2-h exposure to 0.2 ppm ozone. Employing a single-blind cross-over design protocol, 13 white men with ...

  18. Effects of a Chronic Lower Range of Triclosan Exposure on a Stream Mesocosm Community

    Science.gov (United States)

    Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) is an antimicrobial found in consumer soaps and toothpaste. It is in treated wastewater effluents at low part per billion concentrations, representing a potentially chronic exposure condition for biota inhabiting receiving strea...

  19. Consideration of measurement errors in the analysis of the risk related to the exposure to ionising radiation in an occupational cohort: application to the French cohort of uranium miners

    International Nuclear Information System (INIS)

    In epidemiological studies, measurement errors in exposure can substantially bias the estimation of the risk associated to exposure. A broad variety of methods for measurement error correction has been developed, but they have been rarely applied in practice, probably because their ability to correct measurement error effects and their implementation are poorly understood. Another important reason is that many of the proposed correction methods require to know measurement errors characteristics (size, nature, structure and distribution). The aim of this thesis is to take into account measurement error in the analysis of risk of lung cancer death associated to radon exposure based on the French cohort of uranium miners. The mains stages were (1) to assess the characteristics (size, nature, structure and distribution) of measurement error in the French uranium miners cohort, (2) to investigate the impact of measurement error in radon exposure on the estimated excess relative risk (ERR) of lung cancer death associated to radon exposure, and (3) to compare the performance of methods for correction of these measurement error effects. The French cohort of uranium miners includes more than 5000 miners chronically exposed to radon with a follow-up duration of 30 years. Measurement errors have been characterized taking into account the evolution of uranium extraction methods and of radiation protection measures over time. A simulation study based on the French cohort of uranium miners has been carried out to investigate the effects of these measurement errors on the estimated ERR and to assess the performance of different methods for correcting these effects. Measurement error associated to radon exposure decreased over time, from more than 45% in the early 70's to about 10% in the late 80's. Its nature also changed over time from mostly Berkson to classical type from 1983. Simulation results showed that measurement error leads to an attenuation of the ERR towards the null

  20. Inequitable Chronic Lead Exposure: A Dual Legacy of Social and Environmental Injustice.

    Science.gov (United States)

    Leech, Tamara G J; Adams, Elizabeth A; Weathers, Tess D; Staten, Lisa K; Filippelli, Gabriel M

    2016-01-01

    Both historic and contemporary factors contribute to the current unequal distribution of lead in urban environments and the disproportionate impact lead exposure has on the health and well-being of low-income minority communities. We consider the enduring impact of lead through the lens of environmental justice, taking into account well-documented geographic concentrations of lead, legacy sources that produce chronic exposures, and intergenerational transfers of risk. We discuss the most promising type of public health action to address inequitable lead exposure and uptake: primordial prevention efforts that address the most fundamental causes of diseases by intervening in structural and systemic inequalities. PMID:27214670

  1. No effect of low-level chronic neonicotinoid exposure on bumblebee learning and fecundity.

    Science.gov (United States)

    Piiroinen, Saija; Botías, Cristina; Nicholls, Elizabeth; Goulson, Dave

    2016-01-01

    In recent years, many pollinators have declined in abundance and diversity worldwide, presenting a potential threat to agricultural productivity, biodiversity and the functioning of natural ecosystems. One of the most debated factors proposed to be contributing to pollinator declines is exposure to pesticides, particularly neonicotinoids, a widely used class of systemic insecticide. Also, newly emerging parasites and diseases, thought to be spread via contact with managed honeybees, may pose threats to other pollinators such as bumblebees. Compared to honeybees, bumblebees could be particularly vulnerable to the effects of stressors due to their smaller and more short-lived colonies. Here, we studied the effect of field-realistic, chronic clothianidin exposure and inoculation with the parasite Nosema ceranae on survival, fecundity, sugar water collection and learning using queenless Bombus terrestris audax microcolonies in the laboratory. Chronic exposure to 1 ppb clothianidin had no significant effects on the traits studied. Interestingly, pesticide exposure in combination with additional stress caused by harnessing bees for Proboscis Extension Response (PER) learning assays, led to an increase in mortality. In contrast to previous findings, the bees did not become infected by N. ceranae after experimental inoculation with the parasite spores, suggesting variability in host resistance or parasite virulence. However, this treatment induced a slight, short-term reduction in sugar water collection, potentially through stimulation of the immune system of the bees. Our results suggest that chronic exposure to 1 ppb clothianidin does not have adverse effects on bumblebee fecundity or learning ability. PMID:27014515

  2. Occupational diseases in uranium and ore miners related to radiation exposure in the Czech Republic in 2002 - 2007

    International Nuclear Information System (INIS)

    Dozens cases of disease of former or present uranium and ore miners are submitted to judgment as occupational diseases every year in the Czech Republic. Patients or attending physicians suggest that these cases are caused by occupational ionizing radiation. Only a part of these cases is qualified as occupational disease, nevertheless they can cause many juridical problems. The term 'occupational disease' is rather juridical term which underlies the right to financial compensation. The causal association with exposure to ionizing radiation cannot be indisputably verified by expert medical opinion. Most diseases in uranium and ore miners, which are proposed as occupational disease, are malignant tumors. The majority of judged cases are lung cancers from radioactive agents. The poster gives general information about all judged cases of occupational diseases in former uranium and ore miners in the Czech Republic in the years 2002-2007. It also provides short information about standards of professional radiation exposure assessment valid in the other countries. Most frequent diseases were lung cancers. Nevertheless the rate of lung cancers acknowledged as occupational disease decreases during the last two decades. Non-melanoma skin cancers are on the second place. The rate of skin cancers increases. We can explain this fact by better diagnostics and by new method which allows more precious assessment of the skin dose. The method is used since 2005. Leukemias are on the third place (1-2 cases in the year). (authors)

  3. Occupational diseases in uranium and ore miners related to radiation exposure in the Czech Republic in 2002 - 2007

    International Nuclear Information System (INIS)

    Dozens cases of disease of former or present uranium and ore miners are submitted to judgment as occupational diseases every year in the Czech Republic. Patients or attending physicians suggest that these cases are caused by occupational ionizing radiation. Only a part of these cases is qualified as occupational disease, nevertheless they can cause many juridical problems. The term 'occupational disease' is rather juridical term which underlies the right to financial compensation. The causal association with exposure to ionizing radiation cannot be indisputably verified by expert medical opinion. Most diseases in uranium and ore miners, which are proposed as occupational disease, are malignant tumors. The majority of judged cases are lung cancers from radioactive agents. The poster gives general information about all judged cases of occupational diseases in former uranium and ore miners in the Czech Republic in the years 2002 -2007. It also provides short information about standards of professional radiation exposure assessment valid in the other countries. Most frequent diseases were lung cancers. Nevertheless the rate of lung cancers acknowledged as occupational disease decreases during the last two decades. Non-melanoma skin cancers are on the second place. The rate of skin cancers increases. We can explain this fact by better diagnostics and by new method which allows more precious assessment of the skin dose. The method is used since 2005. Leukemias are on the third place (1-2 cases in the year). (authors)

  4. Development of risk maps to minimize uranium exposures in the Navajo Churchrock mining district

    Directory of Open Access Journals (Sweden)

    Rock Tommy

    2009-07-01

    Full Text Available Abstract Background Decades of improper disposal of uranium-mining wastes on the Navajo Nation has resulted in adverse human and ecological health impacts as well as socio-cultural problems. As the Navajo people become increasingly aware of the contamination problems, there is a need to develop a risk-communication strategy to properly inform tribal members of the extent and severity of the health risks. To be most effective, this strategy needs to blend accepted risk-communication techniques with Navajo perspectives such that the strategy can be used at the community level to inform culturally- and toxicologically-relevant decisions about land and water use as well as mine-waste remediation. Objective The objective of this study was to develop GIS-based thematic maps as communication tools to clearly identify high risk exposure areas and offer alternatives to minimize public and ecological health impacts. Methods Thematic maps were produced that incorporated data derived from environmental sampling and public health surveys. The maps show the location and quality of unregulated water resources and identify regulated water sources that could be used as alternatives. In addition, the maps show the location of contaminated soil and sediment areas in which disturbance of surface deposits should be avoided. Preliminary feedback was collected from an informal Navajo working group to assess the clarity and efficacy of this proposed communication method. Results The working group found the maps to be both clear and effective, and made suggestions for improvements, such as the addition of more map features. The working group predicted that once the maps are presented to the public, water hauling and soil use behaviors will change, and dialogue with chapter officials will be initiated to accelerate further risk reduction efforts. Implications Because risk communication is complicated by language barriers, lack of infrastructure, and historical mistrust

  5. Uptake of uranium in Atlantic salmon gills following exposure experiments demonstrated by SR-XRF tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lind, O.C.; Cagno, S.; Brit Salbu, H.C.T. [Centre of Excellence in Environmental Radioactivity - CERAD, Norwegian University of Life Sciences - UMB (Norway); Vanmeert, F.; Nuyts, G.; Janssens, K. [University of Antwerp (Belgium); Alfeld, M.; Falkenberg, G. [Deutsches Elektronen-Synchrotron - DESY (Germany)

    2014-07-01

    Uranium is a naturally occurring radionuclide as well as a heavy metal that can be found in elevated concentrations (mg/L) in the aquatic environment and therefore may pose a risk to aquatic organisms including fish. The major challenges in monitoring the fate of U in complex media, such as soils, sediments and water are to identify mobile and bioavailable U species, interactions with environmental components, transfer to organisms via sorption to surfaces and across membranes, and the internal distribution of target organs. As part of a larger study, U accumulation in gills and internal organs (e.g. liver) as well as mortality of Atlantic Salmon (Salmo salar) were studied as a function of U concentration as well as pH of the exposure water. As Atlantic salmon does not ingest freshwater, the major pathway for uptake of U in the liver is hypothesized to be by transfer across the gills. However, to our best knowledge, active uptake of U within gill filaments has never been proven. In the present work, we demonstrate that following 96 hours exposure of 6 mg U/l in freshwater at pH 7 and 1 mg U/l at pH 5, U was actively taken up in the Atlantic Salmon gill filaments. The internal distribution of U within exposed organisms was visualized using μXRF/μXRD two-dimensional scanning and XRF/XRD tomography at the microprobe end-station of the PETRA III P06 beamline. The recently developed and highly efficient Maia detector array was successfully employed to record extended high-resolution element-specific maps of the tissue samples. First, conventional 2D μXRF/μXRD mapping allowed to identify the axial planes in the samples actually containing U. On the same samples, higher resolution virtual cross-sections were obtained (18 keV, 0.6 μm beam size) by means of μXRF/μXRD tomography of the planes in which U was encountered. The results proved that U not only adheres to the external boundary of the fish gills, but it is also taken up via gills. The results of this work

  6. Characterisation of cochlear inflammation in mice following acute and chronic noise exposure.

    Science.gov (United States)

    Tan, Winston J T; Thorne, Peter R; Vlajkovic, Srdjan M

    2016-08-01

    Oxidative stress has been established as the key mechanism of the cochlear damage underlying noise-induced hearing loss, however, emerging evidence suggests that cochlear inflammation may also be a major contributor. This study aimed to improve our understanding of the cochlear inflammatory response associated with acute and chronic noise exposure. C57BL/6 mice were exposed to acute traumatic noise (100 dBSPL, 8-16 kHz for 24 h) and their cochleae collected at various intervals thereafter, up to 7 days. Using quantitative RT-PCR and immunohistochemistry, changes in expression levels of proinflammatory cytokines (TNF-α, IL-1β), chemokines (CCL2) and cell adhesion molecules (ICAM-1) were studied. All gene transcripts displayed similar dynamics of expression, with an early upregulation at 6 h post-exposure, followed by a second peak at 7 days. ICAM-1 immunoexpression increased significantly in the inferior region of the spiral ligament, peaking 24 h post-exposure. The early expression of proinflammatory mediators likely mediates the recruitment and extravasation of inflammatory cells into the noise-exposed cochlea. The occurrence of the latter expression peak is not clear, but it may be associated with reparative processes initiated in response to cochlear damage. Chronic exposure to moderate noise (90 dBSPL, 8-16 kHz, 2 h/day, up to 4 weeks) also elicited an inflammatory response, reaching a maximum after 2 weeks, suggesting that cochlear damage and hearing loss associated with chronic environmental noise exposure may be linked to inflammatory processes in the cochlea. This study thus provides further insight into the dynamics of the cochlear inflammatory response induced by exposure to acute and chronic noise. PMID:27109494

  7. Inflammation mediators in employees in chronic exposure to neurotoxicants

    Directory of Open Access Journals (Sweden)

    Galina Bodienkova

    2014-08-01

    Full Text Available Objectives: The aim of this work is to perform comparative estimation of cytokines levels in chlorinated hydrocarbons and metallic mercury exposure in employees in the dynamics of neurologic disorders formation. Material and Methods: The contents of cytokines IL-1β, IL-2, IL-4, IL-6, TNF-α, INF-γ were determined in blood sera using the method of hardphasic immunoferment analysis. The significance of different average values was assessed using the parametric and non-parametric criteria - Student (in normal distribution and Mann-Whitney tests taking into account the Bonferonni correction (non-difference from normal distribution. Results: It was shown that, a number of inflammation mediators with the dominance, depending on the expositional toxicant and expression of neurological deficiency, take part in the neurointoxication development. Healthy employees show pro-inflammatory responses with different expression degree, which dominate in the immune regulation processes regardless of the expositional factors (metallic mercury vapors and chlorinated hydrocarbons. Conclusions: The production intensity and interconnection between the pro- and anti-inflammatory cytokines may change in the occupational injuries of the nervous system development process. The decrease in the serum concentrations of cytokines along with the increase of clinical manifestation severity may prove dysregulation of the immune system, which promotes maintaining of pathological process and progradient process of neurointoxication. The most obvious is the imbalance of cytokines in the employees exposed to metallic mercury (in all the examined groups that increases neurointoxication in the distant period.

  8. Further studies of long-term ecological effects of exposure to uranium

    International Nuclear Information System (INIS)

    Spatial variability in sampling for soil uranium distribution by a polar coordinate system was evaluated in randomly selected soil cores at the Los Alamos Scientific Laboratory. Variations for surface (0- to 2.5-cm-deep) soils were 0.18 at 10 m from the nuclear weapons test detonation point and 0.96 at 50 m. Results were strongly influenced by past uranium dispersal patterns, variable leaching of uranium debris, and surface water runoff. A total surface (0- to 5-cm) soil uranium inventory within a 12.6-ha circle centered on the E-F detonation point was estimated to be 3000 kg when calculated by soil uranium concentration isopleths and 4500 kg when using annuli of a polar coordinate sampling system. Uranium concentrations in tissues of deer mice (Peromyscus maniculatus) and pocket gophers (Thomomys bottae) were sufficiently different to conclude that the greater bioavailability of uranium in the top few millimeters of soil at E-F Site, combined with the difference in grooming and food habits of the animals, resulted in greater contamination of deer mice than of pocket gophers

  9. Further studies of long-term ecological effects of exposure to uranium

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, W.C.; Miera, F.R. Jr.

    1978-07-01

    Spatial variability in sampling for soil uranium distribution by a polar coordinate system was evaluated in randomly selected soil cores at the Los Alamos Scientific Laboratory. Variations for surface (0- to 2.5-cm-deep) soils were 0.18 at 10 m from the nuclear weapons test detonation point and 0.96 at 50 m. Results were strongly influenced by past uranium dispersal patterns, variable leaching of uranium debris, and surface water runoff. A total surface (0- to 5-cm) soil uranium inventory within a 12.6-ha circle centered on the E-F detonation point was estimated to be 3000 kg when calculated by soil uranium concentration isopleths and 4500 kg when using annuli of a polar coordinate sampling system. Uranium concentrations in tissues of deer mice (Peromyscus maniculatus) and pocket gophers (Thomomys bottae) were sufficiently different to conclude that the greater bioavailability of uranium in the top few millimeters of soil at E-F Site, combined with the difference in grooming and food habits of the animals, resulted in greater contamination of deer mice than of pocket gophers.

  10. CHRONIC DIETARY EXPOSURE WITH INTERMITTENT SPIKE DOSES OF CHLORPYRIFOS FALLS TO ALTER SOMATOSENSORY EVOKED POTENTIALS, COMPOUND NERVE ACTION POTENTIALS, OR NERVE CONDUCTION VELOCITY IN RATS.

    Science.gov (United States)

    Human exposure to pesticides is often characterized by chronic low level exposure with intermittent spiked higher exposures. Cholinergic transmission is involved in sensory modulation in the cortex and cerebellum, and therefore may be altered following chlorpyrifos (CPF) exposure...

  11. Depleted uranium: Metabolic disruptor?

    International Nuclear Information System (INIS)

    The presence of uranium in the environment can lead to long-term contamination of the food chain and of water intended for human consumption and thus raises many questions about the scientific and societal consequences of this exposure on population health. Although the biological effects of chronic low-level exposure are poorly understood, results of various recent studies show that contamination by depleted uranium (DU) induces subtle but significant biological effects at the molecular level in organs including the brain, liver, kidneys and testicles. For the first time, it has been demonstrated that DU induces effects on several metabolic pathways, including those metabolizing vitamin D, cholesterol, steroid hormones, acetylcholine and xenobiotics. This evidence strongly suggests that DU might well interfere with many metabolic pathways. It might thus contribute, together with other man-made substances in the environment, to increased health risks in some regions. (authors)

  12. Influence of radon-daughter exposure rate and uranium ore dust concentration on occurrence of lung tumors

    International Nuclear Information System (INIS)

    Groups of male SPF Wistar rats were exposed concurrently to several levels of radon daughters and uranium ore dust to study the effect of these variables on pulmonary disease states. Clinical pathology data at 1 yr postexposure indicate no significant differences among exposed animals when compared with controls. Preliminary histopathologic data suggest a trend toward increasing lung tumor risk as the exposure rate is decreased (constant total dose), but the differences are not statistically significant at the 0.05 level. A similar trend occurs with decrease in ore dust concentration (except for the 2560-WLM exposure group), but these differences are also not significant at the 0.05 level. The tumor risk is significantly (0.05 level) increased as the exposure level increases from approximately 320 and 640 WLM to 2560 WLM at the high ore dust concentration

  13. Bumblebee learning and memory is impaired by chronic exposure to a neonicotinoid pesticide.

    Science.gov (United States)

    Stanley, Dara A; Smith, Karen E; Raine, Nigel E

    2015-01-01

    Bumblebees are exposed to pesticides applied for crop protection while foraging on treated plants, with increasing evidence suggesting that this sublethal exposure has implications for pollinator declines. The challenges of navigating and learning to manipulate many different flowers underline the critical role learning plays for the foraging success and survival of bees. We assessed the impacts of both acute and chronic exposure to field-realistic levels of a widely applied neonicotinoid insecticide, thiamethoxam, on bumblebee odour learning and memory. Although bees exposed to acute doses showed conditioned responses less frequently than controls, we found no difference in the number of individuals able to learn at field-realistic exposure levels. However, following chronic pesticide exposure, bees exposed to field-realistic levels learnt more slowly and their short-term memory was significantly impaired following exposure to 2.4 ppb pesticide. These results indicate that field-realistic pesticide exposure can have appreciable impacts on learning and memory, with potential implications for essential individual behaviour and colony fitness. PMID:26568480

  14. Chronic Exposure to Ambient Levels of Urban Particles Affects Mouse Lung Development

    Science.gov (United States)

    Mauad, Thais; Rivero, Dolores Helena Rodriguez Ferreira; de Oliveira, Regiani Carvalho; de Faria Coimbra Lichtenfels, Ana Julia; Guimarães, Eliane Tigre; de Andre, Paulo Afonso; Kasahara, David Itiro; de Siqueira Bueno, Heloisa Maria; Saldiva, Paulo Hilário Nascimento

    2008-01-01

    Rationale: Chronic exposure to air pollution has been associated with adverse effects on children's lung growth. Objectives: We analyzed the effects of chronic exposure to urban levels of particulate matter (PM) on selected phases of mouse lung development. Methods: The exposure occurred in two open-top chambers (filtered and nonfiltered) placed 20 m from a street with heavy traffic in São Paulo, 24 hours/day for 8 months. There was a significant reduction of the levels of PM2.5 inside the filtered chamber (filtered = 2.9 ± 3.0 μg/m3, nonfiltered = 16.8 ± 8.3 μg/m3; P = 0.001). At this exposure site, vehicular sources are the major components of PM2.5 (PM ≤ 2.5μm). Exposure of the parental generation in the two chambers occurred from the 10th to the 120th days of life. After mating and birth of offspring, a crossover of mothers and pups occurred within the chambers, resulting in four groups of pups: nonexposed, prenatal, postnatal, and pre+postnatal. Offspring were killed at the age of 15 (n = 42) and 90 (n = 35) days; lungs were analyzed by morphometry for surface to volume ratio (as an estimator of alveolization). Pressure–volume curves were performed in the older groups, using a 20-ml plethysmograph. Measurements and Main Results: Mice exposed to PM2.5 pre+postnatally presented a smaller surface to volume ratio when compared with nonexposed animals (P = 0.036). The pre+postnatal group presented reduced inspiratory and expiratory volumes at higher levels of transpulmonary pressure (P = 0.001). There were no differences among prenatal and postnatal exposure and nonexposed animals. Conclusions: Our data provide anatomical and functional support to the concept that chronic exposure to urban PM affects lung growth. PMID:18596224

  15. The neurological significance of abnormal natural killer cell activity in chronic toxigenic mold exposures.

    Science.gov (United States)

    Anyanwu, Ebere; Campbell, Andrew W; Jones, Joseph; Ehiri, John E; Akpan, Akpan I

    2003-11-13

    Toxigenic mold activities produce metabolites that are either broad-spectrum antibiotics or mycotoxins that are cytotoxic. Indoor environmental exposure to these toxigenic molds leads to adverse health conditions with the main outcome measure of frequent neuroimmunologic and behavioral consequences. One of the immune system disorders found in patients presenting with toxigenic mold exposure is an abnormal natural killer cell activity. This paper presents an overview of the neurological significance of abnormal natural killer cell (NKC) activity in chronic toxigenic mold exposure. A comprehensive review of the literature was carried out to evaluate and assess the conditions under which the immune system could be dysfunctionally interfered with leading to abnormal NKC activity and the involvement of mycotoxins in these processes. The functions, mechanism, the factors that influence NKC activities, and the roles of mycotoxins in NKCs were cited wherever necessary. The major presentations are headache, general debilitating pains, nose bleeding, fevers with body temperatures up to 40 degrees C (104 degrees F), cough, memory loss, depression, mood swings, sleep disturbances, anxiety, chronic fatigue, vertigo/dizziness, and in some cases, seizures. Although sleep is commonly considered a restorative process that is important for the proper functioning of the immune system, it could be disturbed by mycotoxins. Most likely, mycotoxins exert some rigorous effects on the circadian rhythmic processes resulting in sleep deprivation to which an acute and transient increase in NKC activity is observed. Depression, psychological stress, tissue injuries, malignancies, carcinogenesis, chronic fatigue syndrome, and experimental allergic encephalomyelitis could be induced at very low physiological concentrations by mycotoxin-induced NKC activity. In the light of this review, it is concluded that chronic exposures to toxigenic mold could lead to abnormal NKC activity with a wide range

  16. The Neurological Significance of Abnormal Natural Killer Cell Activity in Chronic Toxigenic Mold Exposures

    Directory of Open Access Journals (Sweden)

    Ebere Anyanwu

    2003-01-01

    Full Text Available Toxigenic mold activities produce metabolites that are either broad-spectrum antibiotics or mycotoxins that are cytotoxic. Indoor environmental exposure to these toxigenic molds leads to adverse health conditions with the main outcome measure of frequent neuroimmunologic and behavioral consequences. One of the immune system disorders found in patients presenting with toxigenic mold exposure is an abnormal natural killer cell activity. This paper presents an overview of the neurological significance of abnormal natural killer cell (NKC activity in chronic toxigenic mold exposure. A comprehensive review of the literature was carried out to evaluate and assess the conditions under which the immune system could be dysfunctionally interfered with leading to abnormal NKC activity and the involvement of mycotoxins in these processes. The functions, mechanism, the factors that influence NKC activities, and the roles of mycotoxins in NKCs were cited wherever necessary. The major presentations are headache, general debilitating pains, nose bleeding, fevers with body temperatures up to 40�C (104�F, cough, memory loss, depression, mood swings, sleep disturbances, anxiety, chronic fatigue, vertigo/dizziness, and in some cases, seizures. Although sleep is commonly considered a restorative process that is important for the proper functioning of the immune system, it could be disturbed by mycotoxins. Most likely, mycotoxins exert some rigorous effects on the circadian rhythmic processes resulting in sleep deprivation to which an acute and transient increase in NKC activity is observed. Depression, psychological stress, tissue injuries, malignancies, carcinogenesis, chronic fatigue syndrome, and experimental allergic encephalomyelitis could be induced at very low physiological concentrations by mycotoxin-induced NKC activity. In the light of this review, it is concluded that chronic exposures to toxigenic mold could lead to abnormal NKC activity with a wide

  17. Biological Monitoring for Depleted Uranium Exposure in U.S. Veterans

    OpenAIRE

    Dorsey, Carrie D.; Engelhardt, Susan M.; Squibb, Katherine S.; McDiarmid, Melissa A.

    2009-01-01

    Background As part of an ongoing medical surveillance program for U.S. veterans exposed to depleted uranium (DU), biological monitoring of urine uranium (U) concentrations is offered to any veteran of the Gulf War and those serving in more recent conflicts (post-Gulf War veterans). Objectives Since a previous report of surveillance findings in 2004, an improved methodology for determination of the isotopic ratio of U in urine (235U:238U) has been developed and allows for more definitive evalu...

  18. A safe strategy to decrease fetal lead exposure in a woman with chronic intoxication.

    Science.gov (United States)

    Leiba, Adi; Hu, Howard; Zheng, Amin; Kales, Stefanos N

    2010-08-01

    During pregnancy skeletal lead is mobilized by maternal bone turnover and can threaten fetal development. The exact strategy suggested to women of childbearing age, who were chronically exposed to lead, and, thus, have high bone lead burden, is not well established. We describe 4 years of follow-up of a 29-year-old woman with chronic lead intoxication. We (a) advised her to delay conception until 'toxicological clearance', (b) treated her with multiple courses of lead chelator, DMSA, and (c) prescribed oral calcium. Patient had low blood lead and protoporphyrin level during pregnancy until delivery. Delaying conception, lead chelation, and calcium supplementation can decrease fetal exposure. PMID:20459344

  19. Reaction of fresh water zooplankton community to chronic radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Osipov, D.; Pryakhin, E. [Urals Research Center for Radiation Medicine - URCRM (Russian Federation); Ivanov, I. [FSUE Mayak PA (Russian Federation)

    2014-07-01

    The characteristic features of ecological community as a whole and cenosis of zooplankton organisms as part of it determine the intensity of the processes of self-purification of water and the formation of a particular body of water. Identifying features of the structure and composition of the zooplankton community of aquatic ecosystems exposed to different levels of radiation exposure, it is necessary to identify patterns of changes in zooplankton and hydro-biocenosis as a whole. Industrial reservoirs, the storage of liquid low-level radioactive waste 'Mayak' for decades, have high radiation load. A large range of levels of radioactive contamination (total volume beta-activity in water varies from 2.2x10{sup 3} to 2.3x10{sup 7} Bq/l, total volume alpha-activity - from 2.6x10{sup -1} to 3.1x10{sup 3} Bq/l) provides a unique opportunity to study ecosystems in a number of reservoirs with increasing impact of radiation factor. We studied five reservoirs that were used as the storage of low-and intermediate-level liquid radioactive waste pond and one comparison water body. In parallel with zooplankton sampling water samples were collected for hydro-chemical analysis. 41 indicators were analysed in order to assess the water chemistry. To determine the content of radionuclides in the various components of the ecosystem samples were collected from water, bottom sediments and plankton. Sampling of zooplankton for the quantitative analysis was performed using the method of weighted average auto bathometer. Apshteyn's plankton net of the surface horizon was used for qualitative analysis of the species composition of zooplankton. Software package ERICA Assessment Tool 2012 was used for the calculation of the absorbed dose rate. Species diversity and biomass of zooplankton, the share of rotifers in the number of species, abundance and biomass decrease with the increase of the absorbed dose rate and salinity. The number of species in a sample decreases with the

  20. Response to 'Comments upon human exposure to depleted uranium during and after the Gulf and Balkans conflicts'

    International Nuclear Information System (INIS)

    Dear Sir, Eric Hamilton takes the Royal Society and myself to task for investigating the health hazards of depleted uranium munitions. In his view the matter appears to be clear. Exposures to uranium have been studied extensively for decades in the nuclear industry and there is little evidence of adverse health consequences. Exposures to DU on the battlefield are therefore unlikely to have health consequences and setting up an independent working group to look at the scientific issues only suggests there are doubts about the science, and leads to mistrust and confusion in the minds of the public. This type of robust approach to addressing the risks of exposure to radioactive materials, and of attempting to assuage the concerns of veterans exposed to DU during the Gulf War, may have worked in the past but it doesn't work today. The Royal Society is accused of having failed to address the main issue, which Hamilton considers to be the failure to implement well established and validated monitoring procedures at the time DU weapons were deployed, so that intakes and risks could have been calculated. This is a curious perspective as, from the outset, the remit of the Royal Society working group was to provide an independent view of the science, rather than the deficiencies in procedures, in response to public concerns and to the very different pronouncements about the dangers to health and the environment arising from the deployment of over 300 tonnes of DU munitions in the Gulf War. Some of the comments in the Royal Society reports and the editorial are considered to be questionable or not acceptable. It is not clear which particular aspects cause offence. One aspect appears to be the claim that DU measurements are difficult, where Hamilton appears to misunderstand the nature of the problem of quantifying exposures to DU. Of course uranium concentrations and isotope ratios are routinely measured in the nuclear industry and in geochemical laboratories, but the problem

  1. Low-level chronic exposure to tritium: An improved basis for hazard evaluation

    International Nuclear Information System (INIS)

    The possibility that significant biological effects may result from chronic low-level exposure to 3HOH is the main health and environmental concern regarding tritium from nuclear energy operations. Direct data for such exposure are, however, largely still unavailable. Information on chronic irradiation at low levels derives mostly from γ-ray studies, so extrapolations are necesary for tritium. But controversy exists on tritium's relative biological effectiveness (RBE) compared to γ radiation and on the related quality factor (Q) used for radiation protection (recently adjusted downward from 1.7 to 1). A firmer basis for extrapolation is needed. The author has obtained quantitative data for low-level 3HOH and 60Co γ-ray exposures in the intact mammal. Developing mice were exposed to various doses over 33 days; surviving oocytes were then counted in ovaries and compared with controls, providing dose-response curves for both radiations. By comparing these curves, RBE values were determined. The RBE was found to vary inversely with dose, in accord with the theory of dual radiation action. At γ-ray doses of 50 rads, the RBE was 1.6. It increased at lower doses, reaching a value of approximately 3. With short exposures, the RBE was lower, due possibly to differences in microdistribution of 3H. These results demonstrate that conclusions from both high-dose and short-term experiments are likely to underestimate the effects of low-level chronic exposure to 3HOH. Measurement of the systematic variation of tritium's RBE with dose and recognition of the effect of exposure duration provide a more secure basis for hazard evaluation. (author)

  2. Mitochondrial energy metabolism impairment and liver dysfunction following chronic exposure to dichlorvos

    International Nuclear Information System (INIS)

    Although the effects of acute pesticide poisoning are well known but, hardly any data exists regarding the health effects after long-term low-level exposure. Major unresolved issues include the effect of moderate exposure in the absence of poisoning. The present study elucidates a possible mechanism by which chronic organophosphate exposure (dichlorvos 6 mg/kg b.wt., s.c. for 12 weeks) causes liver dysfunction. Mitochondria, a primary site of cellular energy generation and oxygen consumption represent a likely target for organophosphate poisoning. Therefore, the objective of the current study was planned with an aim to investigate the effect of chronic dichlorvos exposure on liver mitochondrial electron transport chain (ETC), mitochondrial calcium uptake and its implications on the induction of liver enzymes and liver dysfunction in rodent model. Our results indicated decreased mitochondrial electron transfer activities of cytochrome oxidase along with altered mitochondrial complexes I and II activity. This decrease in the activities of electron transport complexes in turn affected the ATP synthesis and ATP levels adversely in the mitochondria isolated from dichlorvos (DDVP) treated rat liver. Mitochondrial preparation from DDVP treated rat liver demonstrated significant increase in mitochondrial Ca2+ uptake and increase ROS levels. The alterations in the mitochondrial calcium uptake, mitochondrial electron transfer enzyme activities and increase ROS levels in turn might have caused an increase in liver enzymes (ALT, AST and ALP). The electron micrographs of liver cells depicted morphological changes in mitochondria as well as nucleus following 12 weeks of exposure to DDVP. These studies provide an evidence of impaired mitochondrial bioenergetics which may lead to liver dysfunction after chronic exposure to dichlorvos.

  3. Professional exposure: a cohort study among the French nuclear industry service contractors. New-Mexico: workers employed in uranium extraction

    International Nuclear Information System (INIS)

    Two short articles on workers' exposure. First, this document briefly reports and comments the results of a retrospective cohort study performed on service providers intervening in the French nuclear industry. It comments the identification of workers, and briefly comments the results of statistical analysis of mortality due to different forms of cancer. It also outlines the problem of dosimetric data acquisition. The second part presents and comments a similar study concerning workers exposed to uranium bore dust in New-Mexico between 1955 and 1990

  4. Chronic exposure of juvenile rats to environmental noise impairs hippocampal cell proliferation in adulthood

    Directory of Open Access Journals (Sweden)

    Fernando Jáuregui-Huerta

    2011-01-01

    Full Text Available Increasing evidence indicates that chronic exposure to environmental noise may permanently affect the central nervous system. The aim of this study was to evaluate the long-term effects of early exposure to environmental noise on the hippocampal cell proliferation of the adult male rat. Early-weaned Wistar rats were exposed for 15 days to a rats′ audiogram-fitted adaptation to a noisy environment. Two months later, the rats were injected with the cellular proliferation marker 5΄bromodeoxiuridine (BrdU, and their brains were processed for immunohistochemical analysis. Coronal sections were immunolabeled with anti-BrdU antibodies to identify new-born cells in dentate gyrus (DG, cornu amonis areas CA1 and CA3. In addition, blood samples were obtained to evaluate corticosterone serum levels after noise exposure. All data are expressed as mean΁standard deviation. For mean comparisons between groups, we used the Student t test. We found an increase in corticosterone serum levels after environmental noise exposure. Interestingly, noise-exposed rats showed a long-term reduction of proliferating cells in the hippocampal formation, as compared to controls. These findings indicate that chronic environmental noise exposure at young ages produces persistent non-auditory impairment that modifies cell proliferation in the hippocampal formation.

  5. Environmental Heavy Metal Exposure and Chronic Kidney Disease in the General Population

    OpenAIRE

    Kim, Nam Hee; Hyun, Young Youl; Lee, Kyu-Beck; Chang, Yoosoo; Rhu, Seungho; Oh, Kook-Hwan; Ahn, Curie

    2015-01-01

    Lead (Pb), mercury (Hg), and cadmium (Cd) are common heavy metal toxins and cause toxicological renal effects at high levels, but the relevance of low-level environmental exposures in the general population is controversial. A total of 1,797 adults who participated in the KNHANES (a cross-sectional nationally representative survey in Korea) were examined, and 128 of them (7.1%) had chronic kidney disease (CKD). Our study assessed the association between Pb, Hg, Cd exposure, and CKD. Blood Pb ...

  6. Chronic disease and early exposure to air-borne mixtures. 2. Exposure assessment.

    Science.gov (United States)

    Argo, James

    2007-10-15

    This work is part of a larger study of the impact of early exposure to releases from industry on the etiology of cancer. Releases from all kraft and sulfite mills, coke ovens, oil refineries, copper, nickel, and lead/zinc smelters operating in Canada during the exposure period of 1967-1970 have been determined. All plumes have been expressed in microg BaP eq/d using the RASH methodology. The releases have been divided into process, boiler fuel, dioxin, and SO2 emissions. Combustion sources have been defined with FIREv6.23. Dioxin congenors are expected in all source types when the boiler fuel is heavy fuel oil, wood or wood bark, or coal. All approximately 90 communities examined have an inverted sex ratio. PMID:17993167

  7. Chronic caffeine or theophylline exposure reduces gamma-aminobutyric acid/benzodiazepine receptor site interactions.

    Science.gov (United States)

    Roca, D J; Schiller, G D; Farb, D H

    1988-05-01

    Methylxanthines, such as caffeine and theophylline, are adenosine receptor antagonists that exert dramatic effects upon the behavior of vertebrate animals by increasing attentiveness, anxiety, and convulsive activity. Benzodiazepines, such as flunitrazepam, generally exert behavioral effects that are opposite to those of methylxanthines. We report the finding that chronic exposure of embryonic brain neurons to caffeine or theophylline reduces the ability of gamma-aminobutyric acid (GABA) to potentiate the binding of [3H]flunitrazepam to the GABA/benzodiazepine receptor. This theophylline-induced "uncoupling" of GABA- and benzodiazepine-binding site allosteric interactions is blocked by chloroadenosine, an adenosine receptor agonist, indicating that the chronic effects of theophylline are mediated by a site that resembles an adenosine receptor. We speculate that adverse central nervous system effects of long-term exposure to methylxanthines such as in caffeine-containing beverages or theophylline-containing medications may be exerted by a cell-mediated modification of the GABAA receptor. PMID:2835648

  8. Chronic ethanol exposure produces tolerance to elevations in neuroactive steroids: Mechanisms and reversal by exogenous ACTH

    OpenAIRE

    Boyd, Kevin N.; Kumar, Sandeep; O'Buckley, Todd K.; Morrow, A. Leslie

    2010-01-01

    Acute ethanol administration increases potent GABAergic neuroactive steroids, specifically (3α,5α)-3-hydroxypregnan-20-one (3α,5α-THP) and (3α,5α)-3,21-dihydroxypregnan-20-one. In addition, neuroactive steroids contribute to ethanol actions. Chronic ethanol exposure results in tolerance to many effects of ethanol, including ethanol-induced increases in neuroactive steroid levels. To determine the mechanisms of tolerance to ethanol-induced increases in neuroactive steroids, we investigated cri...

  9. Acute and chronic toxicity of sodium sulfate to four freshwater organisms in water-only exposures

    Science.gov (United States)

    Wang, Ning; Consbrock, Rebecca A.; Ingersoll, Christopher G.; Hardesty, Douglas K.; Brumbaugh, William G.; Hammer, Edward J.; Bauer, Candice R.; Mount, David R.

    2015-01-01

    The acute and chronic toxicity of sulfate (tested as sodium sulfate) was determined in diluted well water (hardness of 100 mg/L and pH 8.2) with a cladoceran (Ceriodaphnia dubia; 2-d and 7-d exposures), a midge (Chironomus dilutus; 4-d and 41-d exposures), a unionid mussel (pink mucket, Lampsilis abrupta; 4-d and 28-d exposures), and a fish (fathead minnow, Pimephales promelas; 4-d and 34-d exposures). Among the 4 species, the cladoceran and mussel were acutely more sensitive to sulfate than the midge and fathead minnow, whereas the fathead minnow was chronically more sensitive than the other 3 species. Acute-to-chronic ratios ranged from 2.34 to 5.68 for the 3 invertebrates but were as high as 12.69 for the fish. The fathead minnow was highly sensitive to sulfate during the transitional period from embryo development to hatching in the diluted well water, and thus, additional short-term (7- to 14-d) sulfate toxicity tests were conducted starting with embryonic fathead minnow in test waters with different ionic compositions at a water hardness of 100 mg/L. Increasing chloride in test water from 10 mg Cl/L to 25 mg Cl/L did not influence sulfate toxicity to the fish, whereas increasing potassium in test water from 1mg K/L to 3mg K/L substantially reduced the toxicity of sulfate. The results indicate that both acute and chronic sulfate toxicity data, and the influence of potassium on sulfate toxicity to fish embryos, need to be considered when environmental guidance values for sulfate are developed or refined.

  10. The Consequences of adolescent chronic unpredictable stress exposure on brain and behavior

    OpenAIRE

    Hollis, Fiona; Isgor, Ceylan; Kabbaj, Mohamed

    2013-01-01

    There is increasing evidence for adolescence as a time period vulnerable to environmental perturbations such as stress. What is unclear is the persistent nature of the effects of stress and how specific these effects are to the type of stressor. In this review, we describe the effects of chronic, unpredictable stress (CUS) exposure during adolescence on adult behavior and brain morphology and function in animal models. We provide evidence for adolescence as a critical window for the effects o...

  11. Chronic estradiol exposure induces oxidative stress in the hypothalamus to decrease hypothalamic dopamine and cause hyperprolactinemia

    OpenAIRE

    MohanKumar, Sheba M.J.; Kasturi, Badrinarayanan S.; Shin, Andrew C.; Balasubramanian, Priya; Gilbreath, Ebony T.; Subramanian, Madhan; MohanKumar, Puliyur S

    2010-01-01

    Estrogens are known to cause hyperprolactinemia, most probably by acting on the tuberoinfundibular dopaminergic (TIDA) system of the hypothalamus. Dopamine (DA) produced by TIDA neurons directly inhibits prolactin secretion and, therefore, to stimulate prolactin secretion, estrogens inhibit TIDA neurons to decrease DA production. However, the mechanism by which estrogen produces this effect is not clear. In the present study, we used a paradigm involving chronic exposure to low levels of estr...

  12. Pulmonary function and exercise-associated changes with chronic low-level paraquat exposure

    OpenAIRE

    Schenker, M B; Stoecklin, Maria T; Lee, Kiyoung; Lupercio, Rafael; Zeballos, R. Jorge; Enright, Paul; Hennessy, Tamara E.; Laurel A. Beckett

    2004-01-01

    The present study was undertaken to test the hypothesis that chronic, low-level paraquat exposure causes restrictive lung function with gas transfer impairment. Three hundred thirty-eight Costa Rican farm workers from banana, coffee and palm oil farms completed a questionnaire, spirometry and single-breath carbon monoxide diffusing capacity. Subjects 40 years of age or older, without other medical risk factors, completed maximal cardiopulmonary exercise tests. Most (66.6%) were paraquat hand...

  13. Biochemical Impedance on Intracellular Functions of Vitamin B12 in Chronic Toxigenic Mold Exposures

    OpenAIRE

    Ebere C. Anyanwu; Ijeoma Kanu

    2007-01-01

    A majority of patients with neurological disorders with chronic exposures to toxigenic molds and mycotoxins has vitamin B12 deficiency that is unrelated to dietary insufficiency. Vitamin B12 is a source of coenzymes, and participates in intracellular recycling of methionine, and in methionine synthase reactions. The biochemical processes that lead to B12 depletion and deficiency are not fully understood. This paper examines and assesses various most likely biochemical reasons that could imped...

  14. Comparative transcriptomic responses to chronic cadmium, fluoranthene, and atrazine exposure in Lumbricus rubellus.

    Science.gov (United States)

    Svendsen, C; Owen, J; Kille, P; Wren, J; Jonker, M J; Headley, B A; Morgan, A J; Blaxter, M; Stürzenbaum, S R; Hankard, P K; Lister, L J; Spurgeon, D J

    2008-06-01

    Transcriptional responses of a soil-dwelling organism (the earthworm Lumbricus rubellus) to three chemicals, cadmium (Cd), fluoranthene (FA), and atrazine (AZ), were measured following chronic exposure, with the aim of identifying the nature of any shared transcriptional response. Principal component analysis indicated full or partial separation of control and exposed samples for each compound but not for the composite set of all control and exposed samples. Partial least-squares discriminant analysis allowed separation of the control and exposed samples for each chemical and also for the composite data set, suggesting a common transcriptional response to exposure. Genes identified as changing in expression level (by the least stringent test for significance) following exposure to two chemicals indicated a substantial number of common genes (> 127). The three compound overlapping gene set, however, comprised only 25 genes. We suggest that the low commonality in transcriptional response may be linked to the chronic concentrations (approximately 10% EC50) and chronic duration (28 days) used. Annotations of the three compound overlapping gene set indicated that genes from pathways most often associated with responses to environmental stress, such as heat shock, phase I and II metabolism, antioxidant defense, and cation balance, were not represented. The strongest annotation signature was for genes important in mitochondrial function and energy metabolism. PMID:18589989

  15. Biological characterization of radiation exposure and dose estimates for inhaled uranium milling effluents. Annual progress report April 1, 1982-March 31, 1983

    Energy Technology Data Exchange (ETDEWEB)

    Eidson, A.F.

    1984-05-01

    The problems addressed are the protection of uranium mill workers from occupational exposure to uranium through routine bioassay programs and the assessment of accidental worker exposures. Comparisons of chemical properties and the biological behavior of refined uranium ore (yellowcake) are made to identify important properties that influence uranium distribution patterns among organs. These studies will facilitate calculations of organ doses for specific exposures and associated health risk estimates and will identify important bioassay procedures to improve evaluations of human exposures. A quantitative analytical method for yellowcake was developed based on the infrared absorption of ammonium diuranate and U/sub 3/O/sub 8/ mixtures in KBr. The method was applied to yellowcake samples obtained from six operating mills. The composition of yellowcake from the six mills ranged from nearly pure ammonium diuranate to nearly pure U/sub 3/O/sub 8/. The composition of yellowcake samples taken from lots from the same mill was only somewhat less variable. Because uranium mill workers might be exposed to yellowcake either by contamination of a wound or by inhalation, a study of retention and translocation of uranium after subcutaneous implantation in rats was done. The results showed that 49% of the implanted yellowcake cleared from the body with a half-time (T sub 1/2) in the body of 0.3 days, and the remainder was cleared with a T sub 1/2 of 11 to 30 days. Exposures of Beagle dogs by nose-only inhalation to aerosols of commercial yellowcake were completed. Biochemical indicators of kidney dysfunction that appeared in blood and urine 4 to 8 days after exposure to the more soluble yellowcake showed significant changes in dogs, but levels returned to normal by 16 days after exposure. No biochemical evidence of kidney dysfunction was observed in dogs exposed to the less soluble yellowcake form. 18 figures, 9 tables.

  16. Biological characterization of radiation exposure and dose estimates for inhaled uranium milling effluents. Annual progress report April 1, 1982-March 31, 1983

    International Nuclear Information System (INIS)

    The problems addressed are the protection of uranium mill workers from occupational exposure to uranium through routine bioassay programs and the assessment of accidental worker exposures. Comparisons of chemical properties and the biological behavior of refined uranium ore (yellowcake) are made to identify important properties that influence uranium distribution patterns among organs. These studies will facilitate calculations of organ doses for specific exposures and associated health risk estimates and will identify important bioassay procedures to improve evaluations of human exposures. A quantitative analytical method for yellowcake was developed based on the infrared absorption of ammonium diuranate and U3O8 mixtures in KBr. The method was applied to yellowcake samples obtained from six operating mills. The composition of yellowcake from the six mills ranged from nearly pure ammonium diuranate to nearly pure U3O8. The composition of yellowcake samples taken from lots from the same mill was only somewhat less variable. Because uranium mill workers might be exposed to yellowcake either by contamination of a wound or by inhalation, a study of retention and translocation of uranium after subcutaneous implantation in rats was done. The results showed that 49% of the implanted yellowcake cleared from the body with a half-time (T sub 1/2) in the body of 0.3 days, and the remainder was cleared with a T sub 1/2 of 11 to 30 days. Exposures of Beagle dogs by nose-only inhalation to aerosols of commercial yellowcake were completed. Biochemical indicators of kidney dysfunction that appeared in blood and urine 4 to 8 days after exposure to the more soluble yellowcake showed significant changes in dogs, but levels returned to normal by 16 days after exposure. No biochemical evidence of kidney dysfunction was observed in dogs exposed to the less soluble yellowcake form. 18 figures, 9 tables

  17. Studies of long-term ecological effects of exposure to uranium V

    International Nuclear Information System (INIS)

    Research performed by the Los Alamos Scientific Laboratory (LASL) for the Air Force Armament Laboratory, Eglin Air Force Base, Florida, is reported. A statistical technique called kriging was used to analyze the uranium concentrations in surface soil at E-F Site (LASL). Kriging provided a much more realistic contour surface for uranium concentrations than either a polynomial trend analysis or contouring the original data. The major advantages of kriging are that a measure of the uncertainty of the contoured surface is provided, and that the nonparametric nature of the method allows very irregular surfaces to be fitted. A function relating the uranium counting efficiency of the phoswich portable survey instrument to ambient temperature (10 to 300C) was developed. Counting efficiency is maximum at approximately 100C and declines significantly at higher sample temperatures. The counting efficiency of the phoswich was not affected by soil moisture or relative humidity

  18. Age influence on mice lung tissue response to [i]Aspergillus fumigatus[/i] chronic exposure

    Directory of Open Access Journals (Sweden)

    Marta Kinga Lemieszek

    2015-02-01

    Full Text Available [b]Introduction and objective[/b]. Exposure to conidia of [i]Aspergillus fumigatus[/i] was described as a causative factor of a number of the respiratory system diseases, including asthma, chronic eosinophilic pneumonia, hypersensitivity pneumonitis and bronchopulmonary aspergillosis. The study investigates the effects of the repeated exposure to [i]A. fumigatus[/i] in mice pulmonary compartment. Our work tackles two, so far insufficiently addressed, important aspects of interaction between affected organism and[i] A. fumigatus[/i]: 1 recurrent character of exposure (characteristic for pathomechanism of the abovementioned disease states and 2 impact of aging, potentially important for the differentiation response to an antigen. [b]Materials and methods[/b]. In order to dissect alterations of the immune system involved with both aging and chronic exposure to [i]A. fumigatus[/i], we used 3- and 18-month-old C57BL/6J mice exposed to repeated[i] A. fumigatus[/i] inhalations for 7 and 28 days. Changes in lung tissue were monitored by histological and biochemical evaluation. Concentration of pro- and anti-inflammatory cytokines in lung homogenates was assessed by ELISA tests. [b]Results and conclusions. [/b]Our study demonstrated that chronic inflammation in pulmonary compartment, characterized by the significant increase of proinflammatory cytokines (IL1, IL6, IL10 levels, was the dominant feature of mice response to repeated [i]A. fumigatus[/i] inhalations. The pattern of cytokines’ profile in the course of exposure was similar in both age groups, however in old mice the growth of the cytokines’ levels was more pronounced (especially in case of IL1.

  19. Radionuclides in human hair as indicators of exposure to uranium series radionuclides - Polonium-210 and lead-210 in human hair as indicators of exposure to uranium series radionuclides

    International Nuclear Information System (INIS)

    Polonium-210 and lead-210 were determined in samples of human hair from people living in several regions of Portugal with different radioactivity levels in soils and water. Activity concentration ratios of 210Po/210Pb in the hair were always higher than unity, suggesting that hair is an excretion route for these radionuclides from the human body, especially for 210Po. 210Po activity concentration in the hair increased with the age of people indicating that the source of 210Po body burden is 226Ra deposited in bone, and that this deposit increases with the age of individuals. Furthermore, 210Po activity concentration in the hair was significantly higher in uranium mine workers than in members of the public at large in granite regions, and these ones higher than in people living in low background sedimentary regions, indicating that 210Po concentration in the hair reflected radioactivity levels of the regional environment. 210Pb activity concentrations in the hair seemed more constant throughout life of humans, although reflecting also 210Pb levels in the environment. A relationship is established between 210Po concentration in the hair and 210Po total body burden. (authors)

  20. Mutagenicity monitoring following battlefield exposures: Longitudinal study of HPRT mutations in Gulf War I veterans exposed to depleted uranium.

    Science.gov (United States)

    Albertini, Richard J; Vacek, Pamela M; Carter, Elizabeth W; Nicklas, Janice A; Squibb, Katherine S; Gucer, Patricia W; Engelhardt, Susan M; McDiarmid, Melissa A

    2015-08-01

    A total of 70 military Veterans have been monitored for HPRT T-cell mutations in five separate studies at 2-year intervals over an 8-year period. Systemic depleted uranium (DU) levels were measured at the time of each study by determining urinary uranium (uU) excretion. Each HPRT study included 30-40 Veterans, several with retained DU-containing shrapnel. Forty-nine Veterans were evaluated in multiple studies, including 14 who were in all five studies. This permitted a characterization of the HPRT mutation assay over time to assess the effects of age, smoking and non-selected cloning efficiencies, as well as the inter- and intra-individual variability across time points. Molecular analyses identified the HPRT mutation and T-cell receptor (TCR) gene rearrangement in 1,377 mutant isolates. An unexpected finding was that in vivo clones of HPRT mutant T-cells were present in some Veterans, and could persist over several years of the study. The calculated HPRT mutant frequencies (MFs) were repeatedly elevated in replicate studies in three outlier Veterans with elevated urinary uranium excretion levels. However, these three outlier Veterans also harbored large and persistent in vivo HPRT mutant T-cell clones, each of which was represented by a single founder mutation. Correction for in vivo clonality allowed calculation of HPRT T-cell mutation frequencies (MutFs). Despite earlier reports of DU associated increases in HPRT MFs in some Veterans, the results presented here demonstrate that HPRT mutations are not increased by systemic DU exposure. Additional battlefield exposures were also evaluated for associations with HPRT mutations and none were found. PMID:25914368

  1. Does chronic occupational exposure to volatile anesthetic agents influence the rate of neutrophil apoptosis?

    LENUS (Irish Health Repository)

    Goto, Y

    2012-02-03

    PURPOSE: The purpose of this preliminary investigation was to determine whether the rate of neutrophil apoptosis in health care workers is influenced by exposure to volatile anesthetic agents. METHODS: Percentage neutrophil apoptosis (Annexin-V FITC assay) was measured in health care workers (n = 20) and unexposed volunteers (n = 10). For the health care workers, time weighted personal exposure monitoring to N2O, sevoflurane and isoflurane was carried out. RESULTS: The sevoflurane and isoflurane concentrations to which health care workers were exposed were less than recommended levels in all 20 cases. Percent apoptosis was less at 24 (but not at one and 12) hr culture in health care workers [50.5 (9.7)%; P = 0.008] than in unexposed volunteers [57.3 (5.1)%]. CONCLUSION: Inhibition of neutrophil apoptosis at 24 hr culture was demonstrated in health care workers chronically exposed to volatile anesthetic agents. Exposure was well below recommended levels in the both scavenged and unscavenged work areas in which the study was carried out. Further study is required to assess the effect of greater degrees of chronic exposure to volatile anesthetic agents on neutrophil apoptosis.

  2. Study of internal exposure to uranium compounds in fuel fabrication plants in Brazil

    International Nuclear Information System (INIS)

    The International Commission on Radiological Protection (ICRP) Publication 66 and Supporting Guidance 3) strongly recommends that specific information on lung retention parameters should be used in preference to default values wherever appropriate, for the derivation of effective doses and for bioassay interpretation of monitoring data. A group of 81 workers exposed to UO2 at the fuel fabrication facility in Brazil was selected to evaluate the committed effective dose. The workers were monitored for determination of uranium content in the urinary and faecal excretion. The contribution of intakes by ingestion and inhalation were assessed on the basis of the ratios of urinary to fecal excretion. For the selected workers it was concluded that inhalation dominated intake. According to ICRP 66, uranium oxide is classified as insoluble Type S compound. The ICRP Supporting Guidance 3 and some recent studies have recommended specific lung retention parameters to UO2. The solubility parameters of the uranium oxide compound handled by the workers at the fuel fabrication facility in Brazil was evaluated on the basis of the ratios of urinary to fecal excretion. Excretion data were corrected for dietary intakes. This paper will discuss the application of lung retention parameters recommended by the ICRP models to these data and also the dependence of the effective committed dose on the lung retention parameters. It will also discuss the problems in the interpretation of monitoring results, when the worker is exposed to several uranium compounds of different solubilities. (author)

  3. An intake prior for the bayesian analysis of plutonium and uranium exposures in an epidemiology study

    International Nuclear Information System (INIS)

    In Bayesian inference, the initial knowledge regarding the value of a parameter, before additional data are considered, is represented as a prior probability distribution. This paper describes the derivation of a prior distribution of intake that was used for the Bayesian analysis of plutonium and uranium worker doses in a recent epidemiology study. The chosen distribution is log- normal with a geometric standard deviation of 6 and a median value that is derived for each worker based on the duration of the work history and the number of reported acute intakes. The median value is a function of the work history and a constant related to activity in air concentration, M, which is derived separately for uranium and plutonium. The value of M is based primarily on measurements of plutonium and uranium in air derived from historical personal air sampler (PAS) data. However, there is significant uncertainty on the value of M that results from paucity of PAS data and from extrapolating these measurements to actual intakes. This paper compares posterior and prior distributions of intake and investigates the sensitivity of the Bayesian analyses to the assumed value of M. It is found that varying M by a factor of 10 results in a much smaller factor of 2 variation in mean intake and lung dose for both plutonium and uranium. It is concluded that if a log-normal distribution is considered to adequately represent worker intakes, then the Bayesian posterior distribution of dose is relatively insensitive to the value assumed of M. (authors)

  4. Assessment of radiation exposure around abandoned uranium mining area of Stara planina Mt., Serbia

    Directory of Open Access Journals (Sweden)

    Tanić Milan N.

    2014-01-01

    Full Text Available The aim of this work was to estimate the health and radiation hazard due to external irradiation from terrestrial radionuclides in the Stara planina Mt. region, which is important because of past uranium mining activities on the mountain. Soil samples were collected inside the flotation processing facilities, their surroundings and more distant locations, i.e. from areas considered certainly affected, potentially affected, and unaffected by former mining and uranium ore processing activities. The radiological and health risk assessments were done by calculating the six main parameters, based on the activity concentration of 238U, 232Th, and 40K in soil samples as determined by gamma-ray spectrometry. Increased values of the risk parameters were observed only for sites where uranium ore was processed, while the location surrounding these compounds showed values that are usual for this mountain or slightly above them. Calculations of the risk parameters for the background area showed no radiation risk for the local and seasonal population. The presence of U and Th was detected in all water samples from creeks surrounding the facilities, but only in the water from the facility drainage pipe did their concentration exceed the limits given for the uranium content in drinking water. In conclusion, the results obtained in this study fall within the range of values in similar studies conducted worldwide and are below the values which can cause a significant radiation hazard. [Projekat Ministarstva nauke Republike Srbije, br. III43009 i br. III41005

  5. TBBPA chronic exposure produces sex-specific neurobehavioral and social interaction changes in adult zebrafish.

    Science.gov (United States)

    Chen, Jiangfei; Tanguay, Robert L; Simonich, Michael; Nie, Shangfei; Zhao, Yuxin; Li, Lelin; Bai, Chenglian; Dong, Qiaoxiang; Huang, Changjiang; Lin, Kuangfei

    2016-01-01

    The toxicity of tetrabromobisphenol A (TBBPA) has been extensively studied because of its high production volume. TBBPA is toxic to aquatic fish based on acute high concentration exposure tests, and few studies have assessed the behavioral effects of low concentration chronic TBBPA exposures in aquatic organisms. The present study defined the developmental and neurobehavioral effects associated with exposure of zebrafish to 0, 5 and 50nM TBBPA during 1-120days post-fertilization (dpf) following by detoxification for four months before the behaviors assessment. These low concentration TBBPA exposures were not associated with malformations and did not alter sex ratio, but resulted in reduced zebrafish body weight and length. Adult behavioral assays indicated that TBBPA exposed males had significantly higher average swim speeds and spent significantly more time in high speed darting mode and less time in medium cruising mode compared to control males. In an adult photomotor response assay, TBBPA exposure was associated with hyperactivity in male fish. Female zebrafish responses in these assays followed a similar trend, but the magnitude of TBBPA effects was generally smaller than in males. Social interaction evaluated using a mirror attack test showed that 50nM TBBPA exposed males had heightened aggression. Females exposed to 50nM TBBPA spent more time in the vicinity of the mirror, but did not show increased aggression toward the mirror compared to unexposed control fish. Overall, the hyperactivity and social behavior deficits ascribed here to chronic TBBPA exposure was most profound in males. Our findings indicate that TBBPA can cause developmental and neurobehavioral deficits, and may pose significant health risk to humans. PMID:27221227

  6. Chronic caffeine exposure attenuates blast-induced memory deficit in mice

    Institute of Scientific and Technical Information of China (English)

    Ya-Lei Ning; Nan Yang; Xing Chen; Zi-Ai Zhao; Xiu-Zhu Zhang; Xing-Yun Chen; Ping Li

    2015-01-01

    Objective:To investigate the effects of three different ways of chronic caffeine administration on blastinduced memory dysfunction and to explore the underlying mechanisms.Methods:Adult male C57BL/6 mice were used and randomly divided into five groups:control:without blast exposure,con-water:administrated with water continuously before and after blast-induced traumatic brain injury (bTBI),con-caffeine:administrated with caffeine continuously for 1 month before and after bTBI,pre-caffeine:chronically administrated with caffeine for 1 month before bTBI and withdrawal after bTBI,post-caffeine:chronically administrated with caffeine after bTBI.After being subjected to moderate intensity of blast injury,mice were recorded for learning and memory performance using Morris water maze (MWM) paradigms at 1,4,and 8 weeks post-blast injury.Neurological deficit scoring,glutamate concentration,proinflammatory cytokines production,and neuropathological changes at 24 h,1,4,and 8 weeks post-bTBI were examined to evaluate the brain injury in early and prolonged stages.Adenosine A1 receptor expression was detected using qPCR.Results:All of the three ways of chronic caffeine exposure ameliorated blast-induced memory deficit,which is correlated with the neuroprotective effects against excitotoxicity,inflammation,astrogliosis and neuronal loss at different stages of injury.Continuous caffeine treatment played positive roles in both early and prolonged stages of bTBI;pre-bTBl and post-bTBl treatment of caffeine tended to exert neuroprotective effects at early and prolonged stages of bTBI respectively.Up-regulation of adenosine A1 receptor expression might contribute to the favorable effects of chronic caffeine consumption.Conclusion:Since caffeinated beverages are widely consumed in both civilian and military personnel and are convenient to get,the results may provide a promising prophylactic strategy for blast-induced neurotrauma and the consequent cognitive impairment.

  7. Association between pre- and perinatal exposures and Tourette syndrome or chronic tic disorder in the ALSPAC cohort†

    OpenAIRE

    Mathews, Carol A; Scharf, Jeremiah M.; Miller, Laura L; Macdonald-Wallis, Corrie; Lawlor, Debbie A.; Ben-Shlomo, Yoav

    2014-01-01

    Background Tourette syndrome and chronic tic disorder are heritable but aetiologically complex. Although environment plays a role in their development, existing studies of non-genetic risk factors are inconsistent. Aims To examine the association between pre- and perinatal exposures and Tourette syndrome/chronic tic disorder in the Avon Longitudinal Study of Parents and Children (ALSPAC) prospective longitudinal pre-birth cohort. Method Relationships between exposures and Tourette syndrome/ch...

  8. The effect of chronic exposure to highly aggressive mice on hippocampal gene expression of non-aggressive subordinates

    NARCIS (Netherlands)

    Feldker, DEM; Morsink, MC; Veenema, AH; Datson, NA; Proutski, [No Value; Lathouwers, D; de Kloet, ER; Vreugdenhil, E

    2006-01-01

    Exposure to a chronic psychosocial stressor changes the behavioral and neuroendocrine response pattern and causes structural changes in the rodent hippocampus. However, the underlying molecular mechanism of these changes induced by chronic stress is largely unknown. Recently, it was shown that expos

  9. Chronic cadmium exposure in vitro induces cancer cell characteristics in human lung cells

    Energy Technology Data Exchange (ETDEWEB)

    Person, Rachel J.; Tokar, Erik J.; Xu, Yuanyuan; Orihuela, Ruben; Ngalame, Ntube N. Olive; Waalkes, Michael P., E-mail: waalkes@niehs.nih.gov

    2013-12-01

    Cadmium is a known human lung carcinogen. Here, we attempt to develop an in vitro model of cadmium-induced human lung carcinogenesis by chronically exposing the peripheral lung epithelia cell line, HPL-1D, to a low level of cadmium. Cells were chronically exposed to 5 μM cadmium, a noncytotoxic level, and monitored for acquired cancer characteristics. By 20 weeks of continuous cadmium exposure, these chronic cadmium treated lung (CCT-LC) cells showed marked increases in secreted MMP-2 activity (3.5-fold), invasion (3.4-fold), and colony formation in soft agar (2-fold). CCT-LC cells were hyperproliferative, grew well in serum-free media, and overexpressed cyclin D1. The CCT-LC cells also showed decreased expression of the tumor suppressor genes p16 and SLC38A3 at the protein levels. Also consistent with an acquired cancer cell phenotype, CCT-LC cells showed increased expression of the oncoproteins K-RAS and N-RAS as well as the epithelial-to-mesenchymal transition marker protein Vimentin. Metallothionein (MT) expression is increased by cadmium, and is typically overexpressed in human lung cancers. The major MT isoforms, MT-1A and MT-2A were elevated in CCT-LC cells. Oxidant adaptive response genes HO-1 and HIF-1A were also activated in CCT-LC cells. Expression of the metal transport genes ZNT-1, ZNT-5, and ZIP-8 increased in CCT-LC cells culminating in reduced cadmium accumulation, suggesting adaptation to the metal. Overall, these data suggest that exposure of human lung epithelial cells to cadmium causes acquisition of cancer cell characteristics. Furthermore, transformation occurs despite the cell's ability to adapt to chronic cadmium exposure. - Highlights: • Chronic cadmium exposure induces cancer cell characteristics in human lung cells. • This provides an in vitro model of cadmium-induced human lung cell transformation. • This occurred with general and lung specific changes typical for cancer cells. • These findings add insight to the

  10. Chronic cadmium exposure in vitro induces cancer cell characteristics in human lung cells

    International Nuclear Information System (INIS)

    Cadmium is a known human lung carcinogen. Here, we attempt to develop an in vitro model of cadmium-induced human lung carcinogenesis by chronically exposing the peripheral lung epithelia cell line, HPL-1D, to a low level of cadmium. Cells were chronically exposed to 5 μM cadmium, a noncytotoxic level, and monitored for acquired cancer characteristics. By 20 weeks of continuous cadmium exposure, these chronic cadmium treated lung (CCT-LC) cells showed marked increases in secreted MMP-2 activity (3.5-fold), invasion (3.4-fold), and colony formation in soft agar (2-fold). CCT-LC cells were hyperproliferative, grew well in serum-free media, and overexpressed cyclin D1. The CCT-LC cells also showed decreased expression of the tumor suppressor genes p16 and SLC38A3 at the protein levels. Also consistent with an acquired cancer cell phenotype, CCT-LC cells showed increased expression of the oncoproteins K-RAS and N-RAS as well as the epithelial-to-mesenchymal transition marker protein Vimentin. Metallothionein (MT) expression is increased by cadmium, and is typically overexpressed in human lung cancers. The major MT isoforms, MT-1A and MT-2A were elevated in CCT-LC cells. Oxidant adaptive response genes HO-1 and HIF-1A were also activated in CCT-LC cells. Expression of the metal transport genes ZNT-1, ZNT-5, and ZIP-8 increased in CCT-LC cells culminating in reduced cadmium accumulation, suggesting adaptation to the metal. Overall, these data suggest that exposure of human lung epithelial cells to cadmium causes acquisition of cancer cell characteristics. Furthermore, transformation occurs despite the cell's ability to adapt to chronic cadmium exposure. - Highlights: • Chronic cadmium exposure induces cancer cell characteristics in human lung cells. • This provides an in vitro model of cadmium-induced human lung cell transformation. • This occurred with general and lung specific changes typical for cancer cells. • These findings add insight to the relationship

  11. Diffuse parenchymal lung disease in a case of chronic arsenic exposure

    Directory of Open Access Journals (Sweden)

    Somnath Bhattacharya

    2016-01-01

    Full Text Available A 42-year-old housewife, the resident of rural part of West Bengal, presented with gradually progressive exertional dyspnea associated with a dry cough for last 3 years clinical features were suggestive of diffuse parenchymal lung disease (DPLD. Her chest X-ray posteroanterior view and high resolution computed tomography scan of the thorax showed bilateral patchy ground glass opacities and reticulonodular pattern. Search for the etiology revealed classical skin findings of chronic arsenic exposure in the form of generalized darkening and thickening of skin and keratotic lesions over the palms and soles and classical raindrop pigmentation over leg which was present for last 7 years subsequently her bronchoalveolar lavage fluid, hair, nail, and drinking water showed significant amount of arsenic contamination. By exclusion of all known causes of DPLD, we concluded that it was a case of DPLD due to chronic arsenic exposure. To the best of our knowledge, only few case report of DPLD in chronic arsenicosis has been reported till date.

  12. Effects of chronic occupational exposure to anaesthetic gases on the rate of neutrophil apoptosis among anaesthetists.

    LENUS (Irish Health Repository)

    Tyther, R

    2012-02-03

    BACKGROUND AND OBJECTIVE: Volatile anaesthetic agents are known to influence neutrophil function. The aim was to determine the effect of chronic occupational exposure to volatile anaesthetic agents on the rate of neutrophil apoptosis among anaesthetists. To test this hypothesis, we compared the rate of neutrophil apoptosis in anaesthetists who had been chronically exposed to volatile anaesthetic agents with that in unexposed volunteers. METHODS: Venous blood (20 mL) was withdrawn from 24 ASA I-II volunteers, from which neutrophils were isolated, and maintained in culture. At 1, 12 and 24 h in culture, the percentage of neutrophil apoptosis was assessed by dual staining with annexin V-FITC and propidium iodide. RESULTS: At 1 h (but not at 12 and 24 h) in culture, the rate of neutrophil apoptosis was significantly less in the anaesthetists--13.8 (12.9%) versus 34.4 (12.1%) (P = 0.001). CONCLUSIONS: Chronic occupational exposure to volatile anaesthetic agents may inhibit neutrophil apoptosis. This may have implications for anaesthetists and similarly exposed healthcare workers in terms of the adequacy of their inflammatory response.

  13. Striatal proteomic analysis suggests that first L-dopa dose equates to chronic exposure.

    Directory of Open Access Journals (Sweden)

    Birger Scholz

    Full Text Available L-3,4-dihydroxypheylalanine (L-dopa-induced dyskinesia represent a debilitating complication of therapy for Parkinson's disease (PD that result from a progressive sensitization through repeated L-dopa exposures. The MPTP macaque model was used to study the proteome in dopamine-depleted striatum with and without subsequent acute and chronic L-dopa treatment using two-dimensional difference in-gel electrophoresis (2D-DIGE and mass spectrometry. The present data suggest that the dopamine-depleted striatum is so sensitive to de novo L-dopa treatment that the first ever administration alone would be able (i to induce rapid post-translational modification-based proteomic changes that are specific to this first exposure and (ii, possibly, lead to irreversible protein level changes that would be not further modified by chronic L-dopa treatment. The apparent equivalence between first and chronic L-dopa administration suggests that priming would be the direct consequence of dopamine loss, the first L-dopa administrations only exacerbating the sensitization process but not inducing it.

  14. Study of biological effects induced in Arabidopsis thaliana following uranium exposure, including mixed exposure to cadmium or external gamma radiation: applying a multi-biomarkers approach

    OpenAIRE

    Vanhoudt, Nathalie

    2009-01-01

    The aim of this study was first to investigate uranium toxicity effects and to unravel mechanisms by which plants respond to uranium stress. In a next phase, the influence of secondary stressors on uranium induced effects was investigated. The highest uranium concentration of 100 µM uranium is extremely toxic for Arabidopsis thaliana plants with a completely inhibited growth, a fully disturbed nutrient profile, wilting and although making an effort to increase antioxidative defense, suffering...

  15. Cataracts in uranium miners

    International Nuclear Information System (INIS)

    The question was studied of whether or not uranium miners with a long history of work underground develop alterations of the eye lens as a result of a long-term chronic exposure to gamma radiation. Investigated were the area of opacities and the occurrence of alterations of the lens posterior pole in a group of 800 uranium miners (i.e., 1,600 eyes) with work underground longer than 10 years. As against controls, no statistical differences were found in the lens transparency. Significant differences were also not found in the extent of cataracts and the occurrence of posterior pole alterations, nor in the rate of an increased occurrence of cataracts due to age. (L.O.)

  16. Lung cancer risk, exposure to radon and tobacco consumption in a nested case-control study of French uranium miners

    International Nuclear Information System (INIS)

    Introduction: A nested case-control study was conducted among the French uranium miners cohort in order to assess the effect of protract ed radon exposure on lung cancer risk taking into account tobacco consumption. Material and methods: One hundred uranium miners employed by the French company CEA-COGEMA and who died of a lung cancer between 1980 and 1994 were identified as cases among the cohort. For each case, five controls were randomly matched on birth period and attained age at the time of death of the corresponding case. Cumulated radon exposure during employment was reconstructed for each of these 100 cases and 500 controls. Smoking habits were retrospectively determined from three complementary sources: 1) medical files, 2) forms filled in by occupational physicians and 3) questionnaires applied in face-to-face interviews, phone calls or mailings. Analysis was performed by conditional logistic regression using a linear excess relative risk (ERR) model. A multiplicative model was fitted to assess the joint effect of radon exposure and smoking on lung cancer risk. Results: Smoking status was established for 62 cases and 320 controls and two categories ('ever smokers' vs. 'never smokers') were defined. Ninety percent of the cases and 73% of the controls were classified as 'ever smokers'. Mean five-year lagged cumulated radon exposures were 82.0 and 47.6 working level months (WLM) for the cases and the controls, respectively. The excess relative risk per WLM (ERR/WLM) was 1.1% with a 95%-confidence interval (CI) of 0.2-2.0%. When adjusting for smoking, radon exposure effect was little modified (ERR/WLM = 0.8%, 95% -CI = 0.1- 2.8%). The effect of smoking on lung cancer risk was comparable to results reported in previous miners cohorts (OR = 3.04, 95% -CI = 1.20-7.70). Discussion: A consequent effort was carried out to collect smoking status from three sources for the miners included in this nested case-control study. This analysis shows that, when adjusting on

  17. Chronic 835-MHz radiofrequency exposure to mice hippocampus alters the distribution of calbindin and GFAP immunoreactivity.

    Science.gov (United States)

    Maskey, Dhiraj; Pradhan, Jonu; Aryal, Bijay; Lee, Chang-Min; Choi, In-Young; Park, Ki-Sup; Kim, Seok Bae; Kim, Hyung Gun; Kim, Myeung Ju

    2010-07-30

    Exponential interindividual handling in wireless communication system has raised possible doubts in the biological aspects of radiofrequency (RF) exposure on human brain owing to its close proximity to the mobile phone. In the nervous system, calcium (Ca(2+)) plays a critical role in releasing neurotransmitters, generating action potential and membrane integrity. Alterations in intracellular Ca(2+) concentration trigger aberrant synaptic action or cause neuronal apoptosis, which may exert an influence on the cellular pathology for learning and memory in the hippocampus. Calcium binding proteins like calbindin D28-K (CB) is responsible for the maintaining and controlling Ca(2+) homeostasis. Therefore, in the present study, we investigated the effect of RF exposure on rat hippocampus at 835 MHz with low energy (specific absorption rate: SAR=1.6 W/kg) for 3 months by using both CB and glial fibrillary acidic protein (GFAP) specific antibodies by immunohistochemical method. Decrease in CB immunoreactivity (IR) was noted in exposed (E1.6) group with loss of interneurons and pyramidal cells in CA1 area and loss of granule cells. Also, an overall increase in GFAP IR was observed in the hippocampus of E1.6. By TUNEL assay, apoptotic cells were detected in the CA1, CA3 areas and dentate gyrus of hippocampus, which reflects that chronic RF exposure may affect the cell viability. In addition, the increase of GFAP IR due to RF exposure could be well suited with the feature of reactive astrocytosis, which is an abnormal increase in the number of astrocytes due to the loss of nearby neurons. Chronic RF exposure to the rat brain suggested that the decrease of CB IR accompanying apoptosis and increase of GFAP IR might be morphological parameters in the hippocampus damages. PMID:20546709

  18. Hypothermia after chronic mild stress exposure in rats with a history of postnatal maternal separations.

    Science.gov (United States)

    Mrdalj, Jelena; Lundegaard Mattson, Ase; Murison, Robert; Konow Jellestad, Finn; Milde, Anne Marita; Pallesen, Ståle; Ursin, Reidun; Bjorvatn, Bjørn; Grønli, Janne

    2014-03-01

    The circadian system develops and changes in a gradual and programmed process over the lifespan. Early in life, maternal care represents an important zeitgeber and thus contributes to the development of circadian rhythmicity. Exposure to early life stress may affect circadian processes and induce a latent circadian disturbance evident after exposure to later life stress. Disturbance of the normal regulation of circadian rhythmicity is surmised to be an etiological factor in depression. We used postnatal maternal separation in rats to investigate how the early life environment might modify the circadian response to later life unpredictable and chronic stress. During postnatal days 2-14, male Wistar rats (n = 8 per group) were daily separated from their mothers for a period of either 180 min (long maternal separation; LMS) or 10 min (brief maternal separation; BMS). In adulthood, rats were exposed to chronic mild stress (CMS) for 4 weeks. Body temperature, locomotor activity and heart rate were measured and compared before and after CMS exposure. LMS offspring showed a delayed body temperature acrophase compared to BMS offspring. Otherwise, adult LMS and BMS offspring demonstrated similar diurnal rhythms of body temperature, locomotor activity and heart rate. Exposure to CMS provoked a stronger and longer lasting hypothermia in LMS rats than in BMS rats. The thermoregulatory response appears to be moderated by maternal care following reunion, an observation made in the LMS group only. The results show that early life stress (LMS) in an early developmental stage induced a thermoregulatory disturbance evident upon exposure to unpredictable adult life stressors. PMID:24156523

  19. Chronic Exposure to Particulate Nickel Induces Neoplastic Transformation in Human Lung Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Amie L. Holmes

    2013-11-01

    Full Text Available Nickel is a well-known human lung carcinogen with the particulate form being the most potent; however, the carcinogenic mechanism remains largely unknown. Few studies have investigated the genotoxicity and carcinogenicity of nickel in its target cell, human bronchial epithelial cells. Thus, the goal of this study was to investigate the effects of particulate nickel in human lung epithelial cells. We found that nickel subsulfide induced concentration- and time-dependent increases in both cytotoxicity and genotoxicity in human lung epithelial cells (BEP2D. Chronic exposure to nickel subsulfide readily induced cellular transformation, inducing 2.55, 2.9 and 2.35 foci per dish after exposure to 1, 2.5 and 5 μg/cm2 nickel subsulfide, respectively. Sixty-one, 100 and 70 percent of the foci isolated from 1, 2.5, and 5 μg/cm2 nickel subsulfide treatments formed colonies in soft agar and the degree of soft agar colony growth increased in a concentration-dependent manner. Thus, chronic exposure to particulate nickel induces genotoxicity and cellular transformation in human lung epithelial cells.

  20. Reproduction recovery of the crustacean Daphnia magna after chronic exposure to ibuprofen.

    Science.gov (United States)

    Hayashi, Yuya; Heckmann, Lars-Henrik; Callaghan, Amanda; Sibly, Richard M

    2008-05-01

    In mammals, the pharmaceutical ibuprofen (IB), a non-steroidal anti-inflammatory drug, primarily functions by reversibly inhibiting the cyclooxygenase (COX) pathway in the synthesis of eicosanoids (e.g. prostaglandins). Previous studies suggest that IB may act in a similar manner to interrupt production of eicosanoids reducing reproduction in the model crustacean Daphnia magna. On this basis withdrawal of IB should lead to the recovery of D. magna reproduction. Here we test whether the effect of IB is reversible in D. magna, as it is in mammals, by observing reproduction recovery following chronic exposure. D. magna (5-days old) were exposed to a range of IB concentrations (0, 20, 40 and 80 mg l(-1)) for 10 days followed by a 10 day recovery period in uncontaminated water. During the exposure period, individuals exposed to higher concentrations produced significantly fewer offspring. Thereafter, IB-stressed individuals produced offspring faster during recovery, having similar average population growth rates (PGR) (1.15-1.28) to controls by the end of the test. It appears that maternal daphnids are susceptible to IB during egg maturation. This is the first recorded recovery of reproduction in aquatic invertebrates that suffered reproductive inhibition during chronic exposure to a chemical stressor. Our results suggest a possible theory behind the compensatory fecundity that we referred to as 'catch-up reproduction'. PMID:18214676

  1. Metabolic and histopathological alterations in the marine bivalve Mytilus galloprovincialis induced by chronic exposure to acrylamide.

    Science.gov (United States)

    Larguinho, Miguel; Cordeiro, Ana; Diniz, Mário S; Costa, Pedro M; Baptista, Pedro V

    2014-11-01

    Although the neurotoxic and genotoxic potential of acrylamide has been established in freshwater fish, the full breadth of the toxicological consequences induced by this xenobiotic has not yet been disclosed, particularly in aquatic invertebrates. To assess the effects of acrylamide on a bivalve model, the Mediterranean mussel (Mytilus galloprovincialis), two different setups were accomplished: 1) acute exposure to several concentrations of waterborne acrylamide to determine lethality thresholds of the substance and 2) chronic exposure to more reduced acrylamide concentrations to survey phases I and II metabolic endpoints and to perform a whole-body screening for histopathological alterations. Acute toxicity was low (LC50≈400mg/L). However, mussels were responsive to prolonged exposure to chronic concentrations of waterborne acrylamide (1-10mg/L), yielding a significant increase in lipid peroxidation plus EROD and GST activities. Still, total anti-oxidant capacity was not exceeded. In addition, no neurotoxic effects could be determined through acetylcholine esterase (AChE) activity. The findings suggest aryl-hydrocarbon receptor (Ahr)-dependent responses in mussels exposed to acrylamide, although reduced comparatively to vertebrates. No significant histological damage was found in digestive gland or gills but female gonads endured severe necrosis and oocyte atresia. Altogether, the results indicate that acrylamide may induce gonadotoxicity in mussels, although the subject should benefit from further research. Altogether, the findings suggest that the risk of acrylamide to aquatic animals, especially molluscs, may be underestimated. PMID:25262075

  2. Chronic exposure to ethanol in male mice may be associated with hearing loss in offspring

    Directory of Open Access Journals (Sweden)

    Fei Liang

    2015-01-01

    Full Text Available Although paternal ethanol (EtOH abuse has been shown to affect the growth and behavior of offspring, the exact molecular and mechanistic basis remains largely unclear. Methylation alterations in imprinted genes may be related to well-documented teratogenic effects of ethanol. Here we show that chronic paternal ethanol exposure increases the susceptibility to abnormal behavior in offspring through male game epigenetic alteration. In our study, different doses of ethanol (0, 1.1, 3.3 g kg−1 were administered intra-gastrically to male mice and decreased sperm motility was found in the highest ethanol-exposed group compared with the controls. Data also showed a dose-dependent increase in deaf mice of the paternally ethanol-exposed groups. The methylation of H19, Peg3, Ndn and Snrpn was assessed in paternal spermatozoa and in the cerebral cortices of deaf mice. EtOH affected methylation of Peg3 (CpG 3, 7 and 9 in paternal spermatozoa and in the cerebral cortices of deaf mice, but the level of mRNA expression did not change, suggesting that other gene regulation may be involved in these processes. Overall, chronic paternal ethanol exposure could alter the methylation of imprinted genes in sire spermatozoa that could also be passed on to offspring, giving rise to developmental disorders. Our results provide possible epigenetic evidence for a paternal ethanol exposure contribution to Fetal Alcohol Syndrome (FAS.

  3. Chronic exposure to trichloroethene causes early onset of SLE-like disease in female MRL +/+ mice

    International Nuclear Information System (INIS)

    Trichloroethene (TCE) exacerbates the development of autoimmune responses in autoimmune-prone MRL +/+ mice. Although TCE-mediated autoimmune responses are associated with an increase in serum immunoglobulins and autoantibodies, the underlying mechanism of autoimmunity is not known. To determine the progression of TCE-mediated immunotoxicity, female MRL +/+ mice were chronically exposed to TCE through the drinking water (0.5 mg/ml of TCE) for various periods of time. Serum concentrations of antinuclear antibodies increased after 36 and 48 weeks of TCE exposure. Histopathological analyses showed lymphocyte infiltration in the livers of MRL +/+ mice exposed to TCE for 36 or 48 weeks. Lymphocyte infiltration was also apparent in the pancreas, lungs, and kidneys of mice exposed to TCE for 48 weeks. Immunoglobulin deposits in kidney glomeruli were found after 48 weeks of exposure to TCE. Our results suggest that chronic exposure to TCE promotes inflammation in the liver, pancreas, lungs, and kidneys, which may lead to SLE-like disease in MRL +/+ mice

  4. An intake prior for the Bayesian analysis of plutonium and uranium exposures in an epidemiology study.

    Science.gov (United States)

    Puncher, M; Birchall, A; Bull, R K

    2014-12-01

    In Bayesian inference, the initial knowledge regarding the value of a parameter, before additional data are considered, is represented as a prior probability distribution. This paper describes the derivation of a prior distribution of intake that was used for the Bayesian analysis of plutonium and uranium worker doses in a recent epidemiology study. The chosen distribution is log-normal with a geometric standard deviation of 6 and a median value that is derived for each worker based on the duration of the work history and the number of reported acute intakes. The median value is a function of the work history and a constant related to activity in air concentration, M, which is derived separately for uranium and plutonium. The value of M is based primarily on measurements of plutonium and uranium in air derived from historical personal air sampler (PAS) data. However, there is significant uncertainty on the value of M that results from paucity of PAS data and from extrapolating these measurements to actual intakes. This paper compares posterior and prior distributions of intake and investigates the sensitivity of the Bayesian analyses to the assumed value of M. It is found that varying M by a factor of 10 results in a much smaller factor of 2 variation in mean intake and lung dose for both plutonium and uranium. It is concluded that if a log-normal distribution is considered to adequately represent worker intakes, then the Bayesian posterior distribution of dose is relatively insensitive to the value assumed of M. PMID:24191121

  5. The effect of chronic exposure to tobacco smoke on the antibacterial defenses of the lung.

    Science.gov (United States)

    Huber, G L; Pochay, V E; Mahajan, V K; McCarthy, C R; Hinds, W C; Davies, P; Drath, D B; Sornberger, G C

    1977-01-01

    To evaluate the effects of cigarette smoking on the host defenses of the lung, male CD rats were exposed to fresh whole smoke for up to 60 consecutive days. Intrapulmonary deposition of smoke and animal exposure levels, quantified with decachlorobiphenyl and other smoke tracers, indicated a daily cigarette exposure equivalent to approximately a pack and a half per day in man. Pulmonary alveolar macrophage function in situ was quantified by the inactivation of an aerosolized challenge of Staphylococcus aureus six hours after inoculation. Controls (n=120) inactivated 88.8+/-0.64% of the staphylococci. Exposure to whole smoke did not impair intrapulmonary antistaphylococcal defenses, with inactivation rates of 89.8+/-0.97% (n=49) and 89.1+/-0.46% (n=74) at 30 and 60 days, respectively. Inactivation distribution frequency analysis in controls revealed that 7% of animals had inactivation values greater than two standard deviations from the mean. With prolonged exposure mean with less skewing towards the abnormal. Alveolar macrophages harvested from smoked animals were comparable in viability and in vitro antistaphylococcal activity to controls, appeared to be metabolically activated and had specific stereologic ultrastructural alterations. These studies indicate that chronic exposure to tobacco smoke does not impair, and in fact may stimulate, the host defenses of the lung, as evaluated by in vivo and in vitro pulmonary alveolar macrophage function. PMID:843645

  6. Effects of chronic carbon monoxide exposure on fetal growth and development in mice

    Directory of Open Access Journals (Sweden)

    Venditti Carolina C

    2011-12-01

    Full Text Available Abstract Background Carbon monoxide (CO is produced endogenously, and can also be acquired from many exogenous sources: ie. cigarette smoking, automobile exhaust. Although toxic at high levels, low level production or exposure lends to normal physiologic functions: smooth muscle cell relaxation, control of vascular tone, platelet aggregation, anti- inflammatory and anti-apoptotic events. In pregnancy, it is unclear at what level maternal CO exposure becomes toxic to the fetus. In this study, we hypothesized that CO would be embryotoxic, and we sought to determine at what level of chronic CO exposure in pregnancy embryo/fetotoxic effects are observed. Methods Pregnant CD1 mice were exposed to continuous levels of CO (0 to 400 ppm from conception to gestation day 17. The effect on fetal/placental growth and development, and fetal/maternal CO concentrations were determined. Results Maternal and fetal CO blood concentrations ranged from 1.12- 15.6 percent carboxyhemoglobin (%COHb and 1.0- 28.6%COHb, respectively. No significant difference was observed in placental histological morphology or in placental mass with any CO exposure. At 400 ppm CO vs. control, decreased litter size and fetal mass (p Conclusions Exposure to levels at or below 300 ppm CO throughout pregnancy has little demonstrable effect on fetal growth and development in the mouse.

  7. Occupational exposure to nickel, uranium and thorium in a nickel mine

    International Nuclear Information System (INIS)

    The workers involved in mining and milling ores are exposed in the workplace to many hazardous agents that can cause a health detriment. In this work, the measurements obtained in a nickel mineral processing facility in the Brazilian Central-West are presented. One of the most important hazardous agents in this facility is the aerosol present in the air that contains nickel, uranium and thorium. The aerosol is inhaled or ingested, metabolised and deposited in the whole body or in specific organs. The surveillance of internal contamination of workers was performed by analysis of urine, fecal and hair samples. The ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) method was used to analytically determine nickel, uranium and thorium in these biological samples. Additional data were obtained by the collection of air samples in the workplace. A cascade impactor with six stages was used to collect mineral dust particles with an aerodynamic diameter in the range of 0.64 to 19.4 μm. The particles impacted in each stage of the cascade impactor were analysed by PIXE (Particle Induced X ray Emission), which permits the determination of elemental mass air concentration and the MMAD (Mass Median Aerodynamic Diameter). The concentrations of nickel, uranium and thorium were determined in the aerosol samples. All the results were analysed using statistical methods and biokinetical modelling was applied to evaluate the internal contamination and to make a risk estimation. (author)

  8. Persistent modification of Nav1.9 following chronic exposure to insecticides and pyridostigmine bromide

    International Nuclear Information System (INIS)

    Many veterans of the 1991 Gulf War (GW) returned from that conflict with a widespread chronic pain affecting deep tissues. Recently, we have shown that a 60 day exposure to the insecticides permethrin, chlorpyrifos, and pyridostigmine bromide (NTPB) had little influence on nociceptor action potential forming Nav1.8, but increased Kv7 mediated inhibitory currents 8 weeks after treatment. Using the same exposure regimen, we used whole cell patch methods to examine whether the influences of NTPB could be observed on Nav1.9 expressed in muscle and vascular nociceptors. During a 60 day exposure to NTPB, rats exhibited lowered muscle pain thresholds and increased rest periods, but these measures subsequently returned to normal levels. Eight and 12 weeks after treatments ceased, DRG neurons were excised from the sensory ganglia. Whole cell patch studies revealed little change in voltage dependent activation and deactivation of Nav1.9, but significant increases in the amplitude of Nav1.9 were observed 8 weeks after exposure. Cellular studies, at the 8 week delay, revealed that NTPB also significantly prolonged action potential duration and afterhyperpolarization (22 °C). Acute application of permethrin (10 μM) also increased the amplitude of Nav1.9 in skin, muscle and vascular nociceptors. In conclusion, chronic exposure to Gulf War agents produced long term changes in the amplitude of Nav1.9 expressed in muscle and vascular nociceptors. The reported increases in Kv7 amplitude may have been an adaptive response to increased Nav1.9, and effectively suppressed behavioral pain measures in the post treatment period. Factors that alter the balance between Nav1.9 and Kv7 could release spontaneous discharge and produce chronic deep tissue pain. - Highlights: • Rats were treated 60 days with permethrin, chlorpyrifos and pyridostigmine bromide. • 8 weeks after treatments, Nav1.9 activation and deactivation were unchanged. • The amplitude and conductance of Nav1.9 were

  9. Non-neoplastic pulmonary disease from inhaled radon daughters with uranium ore dust in beagle dogs

    International Nuclear Information System (INIS)

    Daily exposures of adult beagle dogs to inhaled radon daughters plus uranium ore dust, with and without concurrent cigarette smoking, for 2 to 5-1/2 yr have produced massive pulmonary fibrosis and severe emphysema. The cumulative exposure doses are similar to those associated with a 5-fold or greater increase in death rate of uranium miners due to chronic respiratory insufficiency, including pneumoconiosis, pulmonary fibrosis, and emphysema

  10. Quantifying Chronic Stress Exposure for Cumulative Risk Assessment: Lessons Learned from a Case Study of Allostatic Load

    Science.gov (United States)

    Although multiple methods of quantifying environmental chemical exposures have been validated for use in human health risk assessment, quantifying chronic stress exposure is more challenging. Stress is a consequence of perceiving an “exposure” (e.g., violence, poverty) as more th...

  11. Assessing the Renal Toxicity of Capstone Depleted Uranium Oxides and Other Uranium Compounds

    International Nuclear Information System (INIS)

    The primary target for uranium toxicity is the kidney. The most frequently used guideline for uranium kidney burdens is the International Commission on Radiation Protection (ICRP) value of 3 (micro)g U/g kidney, a value that is based largely upon chronic studies in animals. In the present effort, we have developed a risk model equation to assess potential outcomes of acute uranium exposure. Twenty-seven previously published case studies in which workers were acutely exposed to soluble compounds of uranium (as a result of workplace accidents) were analyzed. Kidney burdens of uranium for these individuals were determined based on uranium in the urine, and correlated with health effects observed over a period of up to 38 years. Based upon the severity of health effects, each individual was assigned a score (- to +++) and then placed into an Effect Group. A discriminant analysis was used to build a model equation to predict the Effect Group based on the amount of uranium in the kidneys. The model equation was able to predict the Effect Group with 85% accuracy. The risk model was used to predict the Effect Group for Soldiers exposed to DU as a result of friendly fire incidents during the 1991 Gulf War. This model equation can also be used to predict the Effect Group of new cases in which acute exposures to uranium have occurred

  12. Reduced gene expression levels after chronic exposure to high concentrations of air pollutants

    Czech Academy of Sciences Publication Activity Database

    Rössner ml., Pavel; Tulupová, Elena; Rössnerová, Andrea; Líbalová, Helena; Hoňková, Kateřina; Gmuender, H.; Pastorková, Anna; Švecová, Vlasta; Topinka, Jan; Šrám, Radim

    2015-01-01

    Roč. 780, oct (2015), s. 60-70. ISSN 0027-5107 R&D Projects: GA MŽP(CZ) SP/1B3/8/08; GA MŠk(CZ) LO1508; GA ČR GA13-13458S; GA MŠk 2B08005 Institutional support: RVO:68378041 Keywords : chronic exposure * air pollution * gene expression profiles * human health * particulate matter * polycyclic aromatic hydrocarbons Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 3.680, year: 2014

  13. Influence of UF4 physico-chemical properties on the assessment of the chronic exposure to this compound

    International Nuclear Information System (INIS)

    A method was developed in order to assess uranium exposure hazards at work stations based on the industrial experience acquired by Comurhex Malvesi at Narbonne. Applied to uranium tetrafluoride (UF4) the method involves 4 steps: 1. characterization of the industrial compound, including its physico-chemical properties (density, surface area, X-ray spectrum and uranium enrichment); 2. assessment of work station concentrations and particle size distribution (AMAD); 3. In vitro biological solubility with different synthetic fluids such as Gamble solutions with different gases or compounds added (oxygen or superoxide ions O2-) in order to determine the solubility class D, W or Y; 4. workers' monitoring by routine measurements of urinary excretion completed, if necessary, by fecal excretion and γ-spectrometry. Results and present data on UF4 are presented. 3 tabs., 4 figs

  14. Chronic exposure to a beta 2-adrenoceptor agonist increases the airway response to methacholine.

    Science.gov (United States)

    Witt-Enderby, P A; Yamamura, H I; Halonen, M; Palmer, J D; Bloom, J W

    1993-09-01

    Scheduled chronic administration of beta 2-adrenoceptor agonist bronchodilators in patients with asthma recently has been reported to be associated with a worsening of symptoms and an increase in bronchial responsiveness. We wanted to determine whether a 28-day in vivo exposure to albuterol (beta 2-adrenoceptor agonist) altered the response of rabbit airways to the cholinergic agonist methacholine. We found, using in vitro tissue bath techniques, that in mainstem bronchi from rabbits given a 28-day exposure to albuterol, maximum contraction to methacholine was increased in the albuterol-treated group (control group = 1.10 +/- 0.11 g vs. treated group = 1.50 +/- 0.13 g, P airway smooth muscle to methacholine.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7901034

  15. Mutagenicity monitoring following battlefield exposures: Molecular analysis of HPRT mutations in Gulf War I veterans exposed to depleted uranium.

    Science.gov (United States)

    Nicklas, Janice A; Albertini, Richard J; Vacek, Pamela M; Ardell, Stephanie K; Carter, Elizabeth W; McDiarmid, Melissa A; Engelhardt, Susan M; Gucer, Patricia W; Squibb, Katherine S

    2015-08-01

    Molecular studies that involved cDNA and genomic DNA sequencing as well as multiplex PCR of the HPRT gene were performed to determine the molecular mutational spectrum for 1,377 HPRT mutant isolates obtained from 61 Veterans of the 1991 Gulf War, most of whom were exposed to depleted uranium (DU). Mutant colonies were isolated from one to four times from each Veteran (in 2003, 2005, 2007, and/or 2009). The relative frequencies of the various types of mutations (point mutations, deletions, insertions, etc.) were compared between high versus low DU exposed groups, (based on their urine U concentration levels), with HPRT mutant frequency (as determined in the companion paper) and with a database of historic controls. The mutational spectrum includes all classes of gene mutations with no significant differences observed in Veterans related to their DU exposures. PMID:25914382

  16. Lactobacillus rhamnosus GG Effect on Behavior of Zebrafish During Chronic Ethanol Exposure.

    Science.gov (United States)

    Schneider, Ana Claudia Reis; Rico, Eduardo Pacheco; de Oliveira, Diogo Losch; Rosemberg, Denis Broock; Guizzo, Ranieli; Meurer, Fábio; da Silveira, Themis Reverbel

    2016-01-01

    Ethanol is a widely consumed drug, which acts on the central nervous system to induce behavioral alterations ranging from disinhibition to sedation. Recent studies have produced accumulating evidence for the therapeutic role of probiotic bacteria in behavior. We aimed to investigate the effect of Lactobacillus rhamnosus GG (LGG) on the behavior of adult zebrafish chronically exposed to ethanol. Adult wild-type zebrafish were randomly divided into four groups, each containing 15 fish. The following groups were formed: Control (C), received unsupplemented feed during the trial period; Probiotic (P), fed with feed supplemented with LGG; Ethanol (E), received unsupplemented feed and 0.5% of ethanol directly added to the tank water; and Probiotic+Ethanol (P+E), group under ethanol exposure (0.5%) and fed with LGG supplemented feed. After 2 weeks of exposure, the novel tank test was used to evaluate fish behavior, which was analyzed using computer-aided video tracking. LGG alone did not alter swimming behavior of the fish. Ethanol exposure led to robust behavioral effects in the form of reduced anxiety levels, as indicated by increased vertical exploration and more time spent in the upper region of the novel tank. The group exposed to ethanol and treated with LGG behaved similarly to animals exposed to ethanol alone. Taken together, these results show that zebrafish behavior was not altered by LGG per se, as seen in murine models. This was the first study to investigate the effects of a probiotic diet on behavior after a chronic ethanol exposure. PMID:26862467

  17. Growth Responses of Fish During Chronic Exposure of Metal Mixture under Laboratory Conditions

    Directory of Open Access Journals (Sweden)

    Saima Naz and Muhammad Javed

    2013-07-01

    Full Text Available Growth responses of five fish species viz. Catla catla, Labeo rohita, Cirrhina mrigala, Ctenopharyngodon idella and Hypophthalmichthys molitrix were determined, separately, under chronic exposure of binary mixture of metals (Zn+Ni at sub-lethal concentrations (1/3rd of LC50 for 12 weeks. Randomized complete block design (RCBD was followed to conduct this research work. The groups (10 fish each of Catla catla, Labeo rohita, Cirrhina mrigala, Ctenopharyngodon idella and Hypophthalmichthys molitrix having almost similar weights were investigated for their growth responses and metals bioaccumulation patterns in their body organs during chronic exposure of Zn+Ni mixture. The bioaccumulation of metals in the fish body organs viz. gills, liver, kidney, fins, bones, muscle and skin were also determined before and after growth trails under the stress of metals mixture. The exposure of fish to sub-lethal concentrations of mixture caused significant impacts on the average wet weight increments of five fish species. Ctenopharyngodon idella and Labeo rohita attained significantly higher weights, followed by that of Hypophthalmichthys molitrix, Cirrhina mrigala and Catla catla. However, the growth of metals mixture exposed fish species was significantly lesser than that of control fish (un-stressed. Significantly variable condition factor values reflected the degree of fish well-beings that correlated directly with fish growth and metal exposure concentration. Any significant change in feed intake, due to stress, is reflected in terms of fish growth showing the impacts of metal mixture on fish growth were either additive or antagonist / synergistic. Accumulation of all the metals in fish body followed the general order: liver>kidney>gills> skin >muscle> fins >bones.

  18. Effects of Acute and Chronic Heavy Metal (Cu, Cd, and Zn) Exposure on Sea Cucumbers (Apostichopus japonicus).

    Science.gov (United States)

    Li, Li; Tian, Xiangli; Yu, Xiao; Dong, Shuanglin

    2016-01-01

    Acute and chronic toxicity tests were conducted with sea cucumber (Apostichopus japonicus) exposed to heavy metals. Acute toxicity values (96 h LC50) were 2.697, 0.133, and 1.574 mg L(-1) for Zn, Cu, and Cd, respectively, and were ranked in order of toxicity: Cu > Cd > Zn. Under chronic metal exposure the specific growth rates of sea cucumbers decreased with the increase of metal concentration for all the three metals. After acute metal exposure, the oxygen consumption rate (OCR) decreased. The OCRs in all groups were significantly different than control (P muscle > intestine in natural sea water. After chronic Zn, Cu, and Cd exposure, the change pattern of HK and PK in respiratory tree, muscle, and intestine varied slightly. However, the activity of the enzyme showed a general trend of increase and then decrease and the higher the exposure concentration was, the earlier the highest point of enzyme activity was obtained. PMID:27382568

  19. Effect of chronic and subchronic organic solvents exposure on balance control of workers in plant manufacturing adhesive materials.

    Science.gov (United States)

    Herpin, Guillaume; Gargouri, Imed; Gauchard, Gérome C; Nisse, Catherine; Khadhraoui, Moncef; Elleuch, Boubaker; Zmirou-Navier, Denis; Perrin, Philippe P

    2009-02-01

    High-level occupational exposure to volatile organic solvents may elicit neurotoxic effects, especially on central and peripheral structures involved in balance ability. Studies on balance control in relation with exposure levels close to the threshold limit values are scarce. This study aimed to assess the neurotoxic effects of chronic and subchronic exposure to organic solvents among workers in plant manufacturing adhesive materials. Balance control was evaluated in 18 subjects, mainly exposed to n-hexane and toluene, with current median exposure levels of 222 and 102 mg/m(3), respectively, and a median exposure duration of 21 years, and in 32 nonexposed controls, using posturography tests with and without sensory conflicting situations. Tests were undergone at the beginning of the work shift (chronic exposure) following a week end, and after 72 h (subchronic exposure). Balance control performance was lower in chronically exposed workers compared to controls, and got worse after subchronic exposure, particularly during situations, where vestibular information was important. Our study suggests that a low-level and prolonged exposure to volatile organic solvents, mainly n-hexane and toluene, in the workplace is associated with deleterious central effects involved in postural regulation. This neurotoxicity is characterized by difficulties to use the most relevant information to control balance, leading to altered management of sensory conflicting situations. PMID:19384580

  20. Continuous exposure to house dust mite elicits chronic airway inflammation and structural remodeling.

    Science.gov (United States)

    Johnson, Jill R; Wiley, Ryan E; Fattouh, Ramzi; Swirski, Filip K; Gajewska, Beata U; Coyle, Anthony J; Gutierrez-Ramos, José-Carlos; Ellis, Russ; Inman, Mark D; Jordana, Manel

    2004-02-01

    It is now fully appreciated that asthma is a disease of a chronic nature resulting from intermittent or continued aeroallergen exposure leading to airway inflammation. To investigate responses to continuous antigen exposure, mice were exposed to either house dust mite extract (HDM) or ovalbumin intranasally for five consecutive days, followed by 2 days of rest, for up to seven consecutive weeks. Continuous exposure to HDM, unlike ovalbumin, elicited severe and persistent eosinophilic airway inflammation. Flow cytometric analysis demonstrated an accumulation of CD4+ lymphocytes in the lung with elevated expression of inducible costimulator a marker of T cell activation, and of T1/ST2, a marker of helper T Type 2 effector cells. We also detected increased and sustained production of helper T cell Type 2-associated cytokines by splenocytes of HDM-exposed mice on in vitro HDM recall. Histologic analysis of the lung showed evidence of airway remodeling in mice exposed to HDM, with goblet cell hyperplasia, collagen deposition, and peribronchial accumulation of contractile tissue. In addition, HDM-exposed mice demonstrated severe airway hyperreactivity to methacholine. Finally, these responses were studied for up to 9 weeks after cessation of HDM exposure. We observed that whereas airway inflammation resolved fully, the remodeling changes did not resolve and airway hyperreactivity resolved only partly. PMID:14597485

  1. Investigations of subclinical neurogenous damage of persons with chronic occupational exposure to lead and trichlorethylene

    Energy Technology Data Exchange (ETDEWEB)

    Reichenbach, T.

    1980-12-15

    The functions of the peripheral nervous system, for example the maximum and minimum conduction velocities of the ulnar and the radial nerves, were measured in 22 men and 9 women with occupational exposure to lead and in 20 men and 20 women without occupational exposure to lead. The result of the comparison of the obtained measuring values was a decrease of the minimum conduction velocity of the ulnar nerve of the working hand of men exposed to lead. In order to quantify the lead exposure we determined in all test persons the blood lead level, the concentration of free erythrocyteporphyrines in the blood and the hemoglobin concentration. The study reports also about the elcetroneurographic investigations on 7 persons with chronical exposure to trichloroethylene and on 13 comparable persons of a corresponding age group. A correlation between the biochemical and toxicologic parameters and the nervous conduction velocities could be detected neither in the persons exposed to lead nor in those exposed to trichloroethylene. The measured nervous conduction velocities are well comparable with those age-specific indications given in the specialised literature. The dependence of conduction velocity on various parameters as age, temperature, left- or righthandedness and sex is discussed.

  2. Assessment of radiation exposure and evaluation of remedial measures for the uranium mining and milling area of Mailuu Suu, Kyrgyzstan

    International Nuclear Information System (INIS)

    The area of the town of Mailuu Suu, Kyrgyzstan, is polluted by radionuclides and heavy metals in tailing dumps and heaps resulting from the historic exploitation of uranium mines. Radioactive substances are stored in 23 tailings and 10 heaps situated along the Mailuu Suu River. The stability of many tailings is at risk. Attention is mostly directed to Tailing 3, because of its important radionuclide inventory and since threatened by the borders of a major landslide. In the frame of a European Commission-TACIS funded project, a radiological monitoring programme was set up and a radiological assessment was performed for critical group members living in the city of Mailuu Suu, located downstream the tailings, or in the village of Kara Agach, partially located on a uranium mine-waste dump. The actual radiological situation is of no immediate concern for most of the population of Mailuu Suu. The actual external exposure and exposure from radon are, respectively, around 1.2 mSv a-1 and 5 mSv a-1, at both locations. Ingestion dose was negligible for a critical group member living at Mailuu Suu. At Kara Agach, however, under the hypothesis that all food and fodder is cultivated locally, exposure from ingestion is much higher (∼10-30 mSv a-1). Additional dose from irrigation with Mailuu Suu river water is small in actual conditions (-1). However, there is an important possibility that, triggered by an earthquake or a landslide, (part of the) tailing(s) content may be directed to the river Mailuu Suu. In case the content of Tailing 3 is thrust to river, calculated maximum doses are 45 and 77 mSv a-1 for an adult and a child, respectively, for an assumed exposure duration of 2 years. To impede the consequences of a potential disaster, under the TACIS project different remedial options were evaluated for Tailing 3 including in situ stabilisation and tailing translocation. Also more global remedial options for the Mailuu Suu River valley were proposed (translocation of other

  3. Assessment of radiation exposure and evaluation of remedial measures for the uranium mining and milling area of Mailuu Suu, Kyrgyzstan

    Energy Technology Data Exchange (ETDEWEB)

    Vandenhove, Hildegarde; Sweeck, Lieve [SCK-CEN, Boeretang 200, BR1 Building, B-2400 Mol (Belgium); Clerc, Jean-Jacques [Arcadis, 10 avenue Newton, 92350 Le Plessis-Robinson (France); Aitaliev, Anarkul [Ministry of Ecology and Disaster Situations, Bishkek (Kyrgyzstan)

    2006-07-01

    The area of the town of Mailuu Suu, Kyrgyzstan, is polluted by radionuclides and heavy metals in tailing dumps and heaps resulting from the historic exploitation of uranium mines. Radioactive substances are stored in 23 tailings and 10 heaps situated along the Mailuu Suu River. The stability of many tailings is at risk. Attention is mostly directed to Tailing 3, because of its important radionuclide inventory and since threatened by the borders of a major landslide. In the frame of a European Commission-TACIS funded project, a radiological monitoring programme was set up and a radiological assessment was performed for critical group members living in the city of Mailuu Suu, located downstream the tailings, or in the village of Kara Agach, partially located on a uranium mine-waste dump. The actual radiological situation is of no immediate concern for most of the population of Mailuu Suu. The actual external exposure and exposure from radon are, respectively, around 1.2 mSv a{sup -1} and 5 mSv a{sup -1}, at both locations. Ingestion dose was negligible for a critical group member living at Mailuu Suu. At Kara Agach, however, under the hypothesis that all food and fodder is cultivated locally, exposure from ingestion is much higher ({approx}10-30 mSv a{sup -1}). Additional dose from irrigation with Mailuu Suu river water is small in actual conditions (< 0.1 mSv a{sup -1}). However, there is an important possibility that, triggered by an earthquake or a landslide, (part of the) tailing(s) content may be directed to the river Mailuu Suu. In case the content of Tailing 3 is thrust to river, calculated maximum doses are 45 and 77 mSv a{sup -1} for an adult and a child, respectively, for an assumed exposure duration of 2 years. To impede the consequences of a potential disaster, under the TACIS project different remedial options were evaluated for Tailing 3 including in situ stabilisation and tailing translocation. Also more global remedial options for the Mailuu Suu River

  4. Exposure of critical group of population to water radionuclides in area affected by uranium ore mining

    International Nuclear Information System (INIS)

    Waste waters from the uranium industry are decontaminated and then discharged into water courses. Inhabitants of the nearest village on the river form the critical group with regard to radiation burden. The critical radionuclides are Usub(nat), Ra 226, Pb 210 and Po 210 whose concentrations were determined in drinking water, in the water course and in plants watered with water from the river. From obtained data on the consumption of foods of own production and of water for drinking and cooking, a weighted sum was made of the intake of critical radionuclides per year on the conservative assumption that ingestion is the sole form of intake (permissible ingestion under Notice 59/72, Coll. of Laws). Under the said criteria the intake of radionuclides from water and foods of own production is for the critical population group 27 times less than the permissible intake for the population. Decontaminated waste waters from the operation of uranium industries contribute to the radiation burden of the population only negligibly. Radionuclides from the investigated sources represent a minute fraction of permissible intake. (author)

  5. Public radiation exposure due to radon transport from a uranium mine

    International Nuclear Information System (INIS)

    Radon and radon daughter concentrations at locations several kilometres away from a uranium mine are due both to the background sources and the mine-related sources. The contribution of these two types of sources should be distinguished because the authorised limits on public radiation dose apply only to the mine-related sources. Such a distinction can be achieved by measuring radon and radon daughter concentration in the wind sectors containing only the background sources and those in the wind sectors containing both the background and the mine-related sources. This approach has been used to make estimates of public radiation dose due to radon transport from the Ranger Uranium Mine in Australia. The residential town of Jabiru, the non-residential working town of Jabiru East, and the aboriginal camp sites in the vicinity of the mine were considered. The results indicate that, for the groups of population considered, the annual mine-related dose varies between 0.04 and 0.2 mSv. (author)

  6. Depleted uranium: Metabolic disruptor?; Uranium appauvri: perturbateur metabolique?

    Energy Technology Data Exchange (ETDEWEB)

    Souidi, Maamar; Dublineau, Isabelle; Lestaevel, Philippe [Institut de Radioprotection et de Surete Nucleaire - IRSN, Direction de la radioprotection de l' homme, Laboratoire de radiotoxicologie experimentale, Service de radiobiologie et d' epidemiologie, BP 17, 92262 Fontenay-aux-Roses cedex (France)

    2011-11-15

    The presence of uranium in the environment can lead to long-term contamination of the food chain and of water intended for human consumption and thus raises many questions about the scientific and societal consequences of this exposure on population health. Although the biological effects of chronic low-level exposure are poorly understood, results of various recent studies show that contamination by depleted uranium (DU) induces subtle but significant biological effects at the molecular level in organs including the brain, liver, kidneys and testicles. For the first time, it has been demonstrated that DU induces effects on several metabolic pathways, including those metabolizing vitamin D, cholesterol, steroid hormones, acetylcholine and xenobiotics. This evidence strongly suggests that DU might well interfere with many metabolic pathways. It might thus contribute, together with other man-made substances in the environment, to increased health risks in some regions. (authors)

  7. Effects of a chronic lower range of triclosan exposure to a stream mesocosm community

    Science.gov (United States)

    Nietch, C.T.; Quinlan, E.L.; Lazorchak, J.; Impellitteri, C.; Raikow, D.; Walters, David M.

    2013-01-01

    Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) is an antimicrobial found in consumer soaps and toothpaste. It is in treated wastewater effluents at low part per billion concentrations, representing a potentially chronic exposure condition for biota inhabiting receiving streams. A naturally colonized benthos was created using flow-through indoor mesocosms. Then the benthic communities were dosed to achieve different in-stream triclosan concentrations (Control, 0.1, 0.5, 1.0, 5.0, and 10 µg/L) for 56 days. Water quality parameters and endpoints from bacteria to macroinvertebrates plus interacting abiotic components were measured. Effects of triclosan on specific microbial endpoints were observed at all doses, including an effect on litter decomposition dynamics at doses 1.0 µg/L and higher. Resistance of periphytic bacteria to triclosan significantly increased in doses 0.5 µg/L and above. By the end of dosing, the antimicrobial appeared to stimulate the stream periphyton at the three lowest doses while the two highest doses exhibited decreased stocks of periphyton, including significantly lower bacteria cell densities, and cyanobacteria abundance compared to the control. Beside an effect on benthic ostracods, the changes that occurred in the periphyton did not translate to significant change in the colonizing nematodes, the macroinvertebrate community as a whole, or other measurements of stream function. The results shed light on the role a low, chronic exposure to triclosan may play in effluent dominated streams.

  8. Altered social cognition in male BDNF heterozygous mice and following chronic methamphetamine exposure.

    Science.gov (United States)

    Manning, Elizabeth E; van den Buuse, Maarten

    2016-05-15

    Growing clinical evidence suggests that persistent psychosis which occurs in methamphetamine users is closely related to schizophrenia. However, preclinical studies in animal models have focussed on psychosis-related behaviours following methamphetamine, and less work has been done to assess endophenotypes relevant to other deficits observed in schizophrenia. Altered social behaviour is a feature of both the negative symptoms and cognitive deficits in schizophrenia, and significantly impacts patient functioning. We recently found that brain-derived neurotrophic factor (BDNF) heterozygous mice show disrupted sensitization to methamphetamine, supporting other work suggesting an important role of this neurotrophin in the pathophysiology of psychosis and the neuronal response to stimulant drugs. In the current study, we assessed social and cognitive behaviours in methamphetamine-treated BDNF heterozygous mice and wildtype littermate controls. Following chronic methamphetamine exposure male wildtype mice showed a 50% reduction in social novelty preference. Vehicle-treated male BDNF heterozygous mice showed a similar impairment in social novelty preference, with a trend for no further disruption by methamphetamine exposure. Female mice were unaffected in this task, and no groups showed any changes in sociability or short-term spatial memory. These findings suggest that chronic methamphetamine alters behaviour relevant to disruption of social cognition in schizophrenia, supporting other studies which demonstrate a close resemblance between persistent methamphetamine psychosis and schizophrenia. Together these findings suggest that dynamic regulation of BDNF signalling is necessary to mediate the effects of methamphetamine on behaviours relevant to schizophrenia. PMID:26965573

  9. Development of Toxicological Risk Assessment Models for Acute and Chronic Exposure to Pollutants.

    Science.gov (United States)

    Reichwaldt, Elke S; Stone, Daniel; Barrington, Dani J; Sinang, Som C; Ghadouani, Anas

    2016-01-01

    Alert level frameworks advise agencies on a sequence of monitoring and management actions, and are implemented so as to reduce the risk of the public coming into contact with hazardous substances. Their effectiveness relies on the detection of the hazard, but with many systems not receiving any regular monitoring, pollution events often go undetected. We developed toxicological risk assessment models for acute and chronic exposure to pollutants that incorporate the probabilities that the public will come into contact with undetected pollution events, to identify the level of risk a system poses in regards to the pollutant. As a proof of concept, we successfully demonstrated that the models could be applied to determine probabilities of acute and chronic illness types related to recreational activities in waterbodies containing cyanotoxins. Using the acute model, we identified lakes that present a 'high' risk to develop Day Away From Work illness, and lakes that present a 'low' or 'medium' risk to develop First Aid Cases when used for swimming. The developed risk models succeeded in categorising lakes according to their risk level to the public in an objective way. Modelling by how much the probability of public exposure has to decrease to lower the risks to acceptable levels will enable authorities to identify suitable control measures and monitoring strategies. We suggest broadening the application of these models to other contaminants. PMID:27589798

  10. Effects of Chronic Exposure to Sodium Arsenate on Kidney of Rats

    Directory of Open Access Journals (Sweden)

    Namdar Yousofvand

    2015-09-01

    Full Text Available Background: In the present study, histopathological effects of chronic exposure to sodium arsenate in drinkable water were studied on a quantity of organs of rat. Methods: Rats were divided into two groups, group I; served as control group, were main-tained on deionized drinkable water for 2 months, and group II; the study group were given 60 g/ml of sodium arsenate in deionized drinkable water for 2 months. Blood and urine samples from two groups of animals were collected under anesthesia and the animals were sacrificed under deep anesthesia (a-chloralose, 100 mg/kg, I.P. Their kidney, liver, aorta, and heart were dissected out and cleaned of surrounding connective tissue. The organs were kept in formaldehyde (10% for histopathologic examination. Serum and urine samples from two groups were collected and analyzed for arsenic level. Total quantity of arsenic in serum and urine of animal was measured through graphic furnace atomic absorption spectrometry (GF-AAS. Results:Examination with light microscopy did not show any visible structural changes in the aorta, myocardium, and liver of chronic arsenic treated animals.However, a significant effect was observed in the kidneys of chronic arsenic treated rats showing distinct changes in proxi-mal tubular cells. There was high concentration of arsenic in serum and urine of arsenic ex-posed animals (group II significantly (P<0.001. Conclusion:Swollen tubular cells in histopathologic study of kidney may suggest toxic effects of arsenic in the body.

  11. Acute and chronic ethanol exposure differentially affect induction of hippocampal LTP.

    Science.gov (United States)

    Fujii, Satoshi; Yamazaki, Yoshihiko; Sugihara, Toshimichi; Wakabayashi, Ichiro

    2008-05-23

    Using hippocampal slices, we found that chronic ethanol consumption by rats induces tolerance to the impairing effects of acute ethanol treatment on induction of long-term potentiation (LTP) in CA1 neurons. In hippocampal slices from pair-fed control rats, stable LTP was induced by tetanic stimulation consisting of 25 or more pulses at 100 Hz, but not by tetanic stimulation of 15 pulses at 100 Hz, and LTP induction was blocked if the tetanus was delivered in the presence of 8.6 mM ethanol, 1 microM muscimol, a gamma-aminobutyric acid (GABA) A receptor agonist, or 2.5 microM dl-2-amino-5-phosphonovaleric acid (AP5), an N-methyl-d-aspartate (NMDA) receptor antagonist. In hippocampal slices from rats chronically fed a liquid diet containing ethanol, a tetanus consisting of 15 pulses at 100 Hz did induce stable LTP, indicating a decrease in the stimulation threshold for inducing LTP. Application of ethanol, muscimol, or AP5 did not affect LTP induction in these cells, suggesting that the effects of chronic ethanol exposure on LTP induction are mediated by a reduction in GABAergic inhibition or an increase in NMDA receptor activity in hippocampal CA1 neurons. PMID:18423576

  12. Effect of chronic exposure to aspartame on oxidative stress in the brain of albino rats

    Indian Academy of Sciences (India)

    Ashok Iyyaswamy; Sheeladevi Rathinasamy

    2012-09-01

    This study was aimed at investigating the chronic effect of the artificial sweetener aspartame on oxidative stress in brain regions of Wistar strain albino rats. Many controversial reports are available on the use of aspartame as it releases methanol as one of its metabolite during metabolism. The present study proposed to investigate whether chronic aspartame (75 mg/kg) administration could release methanol and induce oxidative stress in the rat brain. To mimic the human methanol metabolism, methotrexate (MTX)-treated rats were included to study the aspartame effects. Wistar strain male albino rats were administered with aspartame orally and studied along with controls and MTX-treated controls. The blood methanol level was estimated, the animal was sacrificed and the free radical changes were observed in brain discrete regions by assessing the scavenging enzymes, reduced glutathione, lipid peroxidation (LPO) and protein thiol levels. It was observed that there was a significant increase in LPO levels, superoxide dismutase (SOD) activity, GPx levels and CAT activity with a significant decrease in GSH and protein thiol. Moreover, the increases in some of these enzymes were region specific. Chronic exposure of aspartame resulted in detectable methanol in blood. Methanol per se and its metabolites may be responsible for the generation of oxidative stress in brain regions.

  13. Analysis of dose-rate effects on cellular responses to chronic radiation exposure

    International Nuclear Information System (INIS)

    The effects in the title were studied on their expression of various genes concerned with radiation exposure by the acute (1 Gy/min) and chronic (0.007-0.694 Gy/min) irradiations to various cell lines. Cell of human origin were the primarily cultured fibroblasts (F), their immortalized strain (imF) by transduction of human teromerase transcriptase (hTERT), breast cancer MCF-7, osteosarcoma U-20S, colon cancer HCT-116 and T-cell leukemia Jurkat. Acute irradiation was done in a gamma-cell with Cs-137 gamma-ray and chronic one, in a CO2-incubator with the Cs-137 source. Expression of genes was analyzed by mRNA sequence with Genome Analyzer. Proteins of p53, p53-Ser15-P, murine double minute 2 (MDM2), p21 and a/b-tubulin were analyzed by Western blotting. D0 values of acute irradiation were found in the range of 1.1-1.4 Gy, suggesting the similar sensitivity of used cells. However, responses to chronic exposure were different from cells to cells: particularly, at 0.347 mGy/min, no effect on growth was observed in cancer-derived cells until 10 days whereas a marked growth inhibition of F and imF cells was seen after 4 days. Arrest of proliferation of F cells after 10 days exposure at 0.347 mGy/min was tentative, but at 0.694 mGy/min, it was irreversible dependently on the exposure time. They were arrested at G0 stage. Gene expression analyzed by mRNA sequence was shown to be changed even by the lowest rate 0.007 mGy/min: levels of protein expressed under control of cancer-suppressing p53 were markedly altered. Western blotting showed an increased expression of examined proteins except for p53, at higher dose than 0.069 mGy/min. Results indicated that the cellular response to radiation involved not only DNA damage but also the process of yielding the damage. (T.T.)

  14. Microfluidic gradient device for studying mesothelial cell migration and the effect of chronic carbon nanotube exposure

    International Nuclear Information System (INIS)

    Cell migration is one of the crucial steps in many physiological and pathological processes, including cancer development. Our recent studies have shown that carbon nanotubes (CNTs), similarly to asbestos, can induce accelerated cell growth and invasiveness that contribute to their mesothelioma pathogenicity. Malignant mesothelioma is a very aggressive tumor that develops from cells of the mesothelium, and is most commonly caused by exposure to asbestos. CNTs have a similar structure and mode of exposure to asbestos. This has raised a concern regarding the potential carcinogenicity of CNTs, especially in the pleural area which is a key target for asbestos-related diseases. In this paper, a static microfluidic gradient device was applied to study the migration of human pleural mesothelial cells which had been through a long-term exposure (4 months) to subcytotoxic concentration (0.02 µg cm−2) of single-walled CNTs (SWCNTs). Multiple migration signatures of these cells were investigated using the microfluidic gradient device for the first time. During the migration study, we observed that cell morphologies changed from flattened shapes to spindle shapes prior to their migration after their sensing of the chemical gradient. The migration of chronically SWCNT-exposed mesothelial cells was evaluated under different fetal bovine serum (FBS) concentration gradients, and the migration speeds and number of migrating cells were extracted and compared. The results showed that chronically SWCNT-exposed mesothelial cells are more sensitive to the gradient compared to non-SWCNT-exposed cells. The method described here allows simultaneous detection of cell morphology and migration under chemical gradient conditions, and also allows for real-time monitoring of cell motility that resembles in vivo cell migration. This platform would be much needed for supporting the development of more physiologically relevant cell models for better assessment and characterization of the

  15. Microfluidic gradient device for studying mesothelial cell migration and the effect of chronic carbon nanotube exposure

    Science.gov (United States)

    Zhang, Hanyuan; Lohcharoenkal, Warangkana; Sun, Jianbo; Li, Xiang; Wang, Liying; Wu, Nianqiang; Rojanasakul, Yon; Liu, Yuxin

    2016-01-01

    Cell migration is one of the crucial steps in many physiological and pathological processes, including cancer development. Our recent studies have shown that carbon nanotubes (CNTs), similarly to asbestos, can induce accelerated cell growth and invasiveness that contribute to their mesothelioma pathogenicity. Malignant mesothelioma is a very aggressive tumor that develops from cells of the mesothelium, and is most commonly caused by exposure to asbestos. CNTs have a similar structure and mode of exposure to asbestos. This has raised a concern regarding the potential carcinogenicity of CNTs, especially in the pleural area which is a key target for asbestos-related diseases. In this paper, a static microfluidic gradient device was applied to study the migration of human pleural mesothelial cells which had been through a long-term exposure (4 months) to subcytotoxic concentration (0.02 μg cm−2) of single-walled CNTs (SWCNTs). Multiple migration signatures of these cells were investigated using the microfluidic gradient device for the first time. During the migration study, we observed that cell morphologies changed from flattened shapes to spindle shapes prior to their migration after their sensing of the chemical gradient. The migration of chronically SWCNT-exposed mesothelial cells was evaluated under different fetal bovine serum (FBS) concentration gradients, and the migration speeds and number of migrating cells were extracted and compared. The results showed that chronically SWCNT-exposed mesothelial cells are more sensitive to the gradient compared to non-SWCNT-exposed cells. The method described here allows simultaneous detection of cell morphology and migration under chemical gradient conditions, and also allows for real-time monitoring of cell motility that resembles in vivo cell migration. This platform would be much needed for supporting the development of more physiologically relevant cell models for better assessment and characterization of the

  16. Chronic exposure to hypergravity affects thyrotropin-releasing hormone levels in rat brainstem and cerebellum

    Science.gov (United States)

    Daunton, N. G.; Tang, F.; Corcoran, M. L.; Fox, R. A.; Man, S. Y.

    1998-01-01

    In studies to determine the neurochemical mechanisms underlying adaptation to altered gravity we have investigated changes in neuropeptide levels in brainstem, cerebellum, hypothalamus, striatum, hippocampus, and cerebral cortex by radioimmunoassay. Fourteen days of hypergravity (hyperG) exposure resulted in significant increases in thyrotropin-releasing hormone (TRH) content of brainstem and cerebellum, but no changes in levels of other neuropeptides (beta-endorphin, cholecystokinin, met-enkephalin, somatostatin, and substance P) examined in these areas were found, nor were TRH levels significantly changed in any other brain regions investigated. The increase in TRH in brainstem and cerebellum was not seen in animals exposed only to the rotational component of centrifugation, suggesting that this increase was elicited by the alteration in the gravitational environment. The only other neuropeptide affected by chronic hyperG exposure was met-enkephalin, which was significantly decreased in the cerebral cortex. However, this alteration in met-enkephalin was found in both hyperG and rotation control animals and thus may be due to the rotational rather than the hyperG component of centrifugation. Thus it does not appear as if there is a generalized neuropeptide response to chronic hyperG following 2 weeks of exposure. Rather, there is an increase only of TRH and that occurs only in areas of the brain known to be heavily involved with vestibular inputs and motor control (both voluntary and autonomic). These results suggest that TRH may play a role in adaptation to altered gravity as it does in adaptation to altered vestibular input following labyrinthectomy, and in cerebellar and vestibular control of locomotion, as seen in studies of ataxia.

  17. Environmental heavy metal exposure and chronic kidney disease in the general population.

    Science.gov (United States)

    Kim, Nam Hee; Hyun, Young Youl; Lee, Kyu-Beck; Chang, Yoosoo; Ryu, Seungho; Rhu, Seungho; Oh, Kook-Hwan; Ahn, Curie

    2015-03-01

    Lead (Pb), mercury (Hg), and cadmium (Cd) are common heavy metal toxins and cause toxicological renal effects at high levels, but the relevance of low-level environmental exposures in the general population is controversial. A total of 1,797 adults who participated in the KNHANES (a cross-sectional nationally representative survey in Korea) were examined, and 128 of them (7.1%) had chronic kidney disease (CKD). Our study assessed the association between Pb, Hg, Cd exposure, and CKD. Blood Pb and Cd levels were correlated with CKD in univariate logistic regression model. However, these environmental heavy metals were not associated with CKD after adjustment for age, sex, BMI, smoking, hyperlipidemia, hypertension, diabetes, and these metals in multivariate logistic regression models. We stratified the analysis according to hypertension or diabetes. In the adults with hypertension or diabetes, CKD had a significant association with elevated blood Cd after adjustment, but no association was present with blood Pb and Hg. The corresponding odds ratio [OR] of Cd for CKD were 1.52 (95% confidence interval [CI], 1.05-2.19, P=0.026) in adults with hypertension and 1.92 (95% CI, 1.14-3.25, P=0.014) in adults with diabetes. Environmental low level of Pb, Hg, Cd exposure in the general population was not associated with CKD. However, Cd exposure was associated with CKD, especially in adults with hypertension or diabetes. This finding suggests that environmental low Cd exposure may be a contributor to the risk of CKD in adults with hypertension or diabetes. PMID:25729249

  18. Metallothionein (MT) response after chronic palladium exposure in the zebra mussel, Dreissena polymorpha

    International Nuclear Information System (INIS)

    The effects of different exposure concentrations of palladium (Pd) on relative metallothionein (MT) response and bioaccumulation were investigated in zebra mussels (Dreissena polymorpha). The mussels were exposed to 0.05, 5, 50, and 500 μg/L Pd2+ for 10 weeks under controlled temperature and fasting conditions. Relative MT contents were assessed by a modified Ag-saturation method, which allows to discriminate between MT bound to Pd (Pd-MT) and MT bound to unidentified metals (Ag-MT). Determination of metal contents resulted from atomic absorption spectrometry following a microwave digestion. For unexposed mussels and mussels exposed to 0.05 μg/L Pd no metal accumulation could be detected. All other exposure concentrations resulted in detectable Pd accumulation in mussels with final tissue concentrations of 96 μg/g (500 μg/L), 45 μg/g (50 μg/L), and 9 μg/g (5 μg/L). Compared with initial levels Pd-MT concentrations at the end of the exposure period were 600 (500 μg/L), 160 (50 μg/L), and 27 (5 μg/L) times higher. These results show that an increase in MTs in D. polymorpha already occurs at relatively low aqueous Pd concentrations indicating that there is the need for detoxification of Pd in the mussel. Furthermore, correlations between Ag-MT and Pd accumulation indicate that higher exposure concentrations are associated with adverse effects on the mussels. Thus, harmful effects of chronic Pd exposure of organisms even in lowest concentrations cannot be excluded in the environment

  19. Chronic subhepatotoxic exposure to arsenic enhances hepatic injury caused by high fat diet in mice

    International Nuclear Information System (INIS)

    Arsenic is a ubiquitous contaminant in drinking water. Whereas arsenic can be directly hepatotoxic, the concentrations/doses required are generally higher than present in the US water supply. However, physiological/biochemical changes that are alone pathologically inert can enhance the hepatotoxic response to a subsequent stimulus. Such a ‘2-hit’ paradigm is best exemplified in chronic fatty liver diseases. Here, the hypothesis that low arsenic exposure sensitizes liver to hepatotoxicity in a mouse model of non-alcoholic fatty liver disease was tested. Accordingly, male C57Bl/6J mice were exposed to low fat diet (LFD; 13% calories as fat) or high fat diet (HFD; 42% calories as fat) and tap water or arsenic (4.9 ppm as sodium arsenite) for ten weeks. Biochemical and histologic indices of liver damage were determined. High fat diet (± arsenic) significantly increased body weight gain in mice compared with low-fat controls. HFD significantly increased liver to body weight ratios; this variable was unaffected by arsenic exposure. HFD caused steatohepatitis, as indicated by histological assessment and by increases in plasma ALT and AST. Although arsenic exposure had no effect on indices of liver damage in LFD-fed animals, it significantly increased the liver damage caused by HFD. This effect of arsenic correlated with enhanced inflammation and fibrin extracellular matrix (ECM) deposition. These data indicate that subhepatotoxic arsenic exposure enhances the toxicity of HFD. These results also suggest that arsenic exposure might be a risk factor for the development of fatty liver disease in human populations. -- Highlights: ► Characterizes a mouse model of arsenic enhanced NAFLD. ► Arsenic synergistically enhances experimental fatty liver disease at concentrations that cause no overt hepatotoxicity alone. ► This effect is associated with increased inflammation.

  20. Chronic Exposure to Bisphenol A Affects Uterine Function During Early Pregnancy in Mice.

    Science.gov (United States)

    Li, Quanxi; Davila, Juanmahel; Kannan, Athilakshmi; Flaws, Jodi A; Bagchi, Milan K; Bagchi, Indrani C

    2016-05-01

    Environmental and occupational exposure to bisphenol A (BPA), a chemical widely used in polycarbonate plastics and epoxy resins, has received much attention in female reproductive health due to its widespread toxic effects. Although BPA has been linked to infertility and recurrent miscarriage in women, the impact of its exposure on uterine function during early pregnancy remains unclear. In this study, we addressed the effect of prolonged exposure to an environmental relevant dose of BPA on embryo implantation and establishment of pregnancy. Our studies revealed that treatment of mice with BPA led to improper endometrial epithelial and stromal functions thus affecting embryo implantation and establishment of pregnancy. Upon further analyses, we found that the expression of progesterone receptor (PGR) and its downstream target gene, HAND2 (heart and neural crest derivatives expressed 2), was markedly suppressed in BPA-exposed uterine tissues. Previous studies have shown that HAND2 controls embryo implantation by repressing fibroblast growth factor and the MAPK signaling pathways and inhibiting epithelial proliferation. Interestingly, we observed that down-regulation of PGR and HAND2 expression in uterine stroma upon BPA exposure was associated with enhanced activation of fibroblast growth factor and MAPK signaling in the epithelium, thus contributing to aberrant proliferation and lack of uterine receptivity. Further, the differentiation of endometrial stromal cells to decidual cells, an event critical for the establishment and maintenance of pregnancy, was severely compromised in response to BPA. In summary, our studies revealed that chronic exposure to BPA impairs PGR-HAND2 pathway and adversely affects implantation and the establishment of pregnancy. PMID:27022677

  1. Decision-making about chronic radiation exposure to the public. New recommendations from the ICRP

    International Nuclear Information System (INIS)

    The paper discusses decision-making in situations of chronic exposure within the framework of a forthcoming related ICRP report on the subject which has been produced by an ICRP Task Group chaired by the author. This ICRP report will provide guidance on the application of the ICRP System of Radiological Protection to prolonged exposure situations afflicting members of the public. It will address the general application of the System to the control of prolonged exposures resulting from practices and to the undertaking of interventions in prolonged exposure situations, and will provide recommendations on generic reference levels for such interventions. It will also consider some specific situations and will discuss a number of issues that have been of concern, namely: natural radiation sources that may give rise to high doses; the restoration and rehabilitation of sites where human activities involving radioactive substances have been carried out; the return to 'normality' following an accident that has released radioactive substances to the environment; and the global marketing of commodities for public consumption that contain relatively high levels of radioactive substances. Annexes will provide some examples of prolonged exposure situations and will discuss the radiological protection quantities, radiation-induced health effects and aspects of the System of Radiological Protection relevant to prolonged exposure. The quantitative recommendations for prolonged exposures provided in the report will be as follows: generic reference levels for intervention, in terms of existing annual doses, of < or approx. 100 mSv, above which intervention is almost always justifiable (situations for which the annual dose threshold for deterministic effects in relevant organs is exceeded will almost always require intervention), and of < or approx.10 mSv, below which intervention is not likely to be justifiable (and above which it may be necessary); intervention exemption levels for

  2. Consideration of measurement errors in the analysis of the risk related to the exposure to ionising radiation in an occupational cohort: application to the French cohort of uranium miners; Prise en compte des erreurs de mesure dans l'analyse du risque associe a l'exposition aux rayonnements ionisants dans une cohorte professionnelle: application a la cohorte francaise des mineurs d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Allodji, Rodrigue Setcheou

    2011-12-09

    In epidemiological studies, measurement errors in exposure can substantially bias the estimation of the risk associated to exposure. A broad variety of methods for measurement error correction has been developed, but they have been rarely applied in practice, probably because their ability to correct measurement error effects and their implementation are poorly understood. Another important reason is that many of the proposed correction methods require to know measurement errors characteristics (size, nature, structure and distribution). The aim of this thesis is to take into account measurement error in the analysis of risk of lung cancer death associated to radon exposure based on the French cohort of uranium miners. The mains stages were (1) to assess the characteristics (size, nature, structure and distribution) of measurement error in the French uranium miners cohort, (2) to investigate the impact of measurement error in radon exposure on the estimated excess relative risk (ERR) of lung cancer death associated to radon exposure, and (3) to compare the performance of methods for correction of these measurement error effects. The French cohort of uranium miners includes more than 5000 miners chronically exposed to radon with a follow-up duration of 30 years. Measurement errors have been characterized taking into account the evolution of uranium extraction methods and of radiation protection measures over time. A simulation study based on the French cohort of uranium miners has been carried out to investigate the effects of these measurement errors on the estimated ERR and to assess the performance of different methods for correcting these effects. Measurement error associated to radon exposure decreased over time, from more than 45% in the early 70's to about 10% in the late 80's. Its nature also changed over time from mostly Berkson to classical type from 1983. Simulation results showed that measurement error leads to an attenuation of the ERR towards

  3. Effects of depleted uranium after short-term exposure on vitamin D metabolism in rat

    Energy Technology Data Exchange (ETDEWEB)

    Tissandie, E.; Gueguen, Y.; Paquet, F.; Aigueperse, J.; Souidi, M. [Institute for Radiological Protection and Nuclear Safety, Laboratory of Experimental Toxicology, BP n 17, Fontenay-aux-Roses Cedex (France); Lobaccaro, J.M.A. [UMR Universite Blaise Pascal-CNRS, Compared Physiology and Molecular Endocrinology, 24 avenue des Landais, 6547, Aubiere Cedex (France)

    2006-08-15

    Uranium is a natural radioactive heavy metal. Its toxicity has been demonstrated for different organs, including bone, kidney, liver and brain. Effects of an acute contamination by depleted uranium (DU) were investigated in vivo on vitamin D{sub 3} biosynthetic pathway. Rats received an intragastric administration of DU (204 mg/kg) and various parameters were studied either on day 1 or day 3 after contamination. Cytochrome P450 (CYP27A1, CYP2R1, CYP27B1, CYP24A1) enzymes involved in vitamin D metabolism and two vitamin D{sub 3}-target genes (ECaC1, CaBP-D9K) were assessed by real time RT-PCR in liver and kidneys. CYP27A1 activity was measured in liver and vitamin D and parathyroid hormone (PTH) level were measured in plasma. In acute treated-rats, vitamin D level was increased by 62% and decreased by 68% in plasma, respectively at day 1 and at day 3, which paralleled with a concomitant decrease of PTH level (90%) at day 3. In liver, cyp2r1 mRNA level was increased at day 3. Cyp27a1 activity decreased at day 1 and increased markedly at day 3. In kidney, cyp27b1 mRNA was increased at days 1 and 3 (11- and 4-fold respectively). Moreover, ecac1 and cabp-d9k mRNA levels were increased at day 1 and decreased at day 3. This work shows for the first time that DU acute contamination modulates both activity and expression of CYP enzymes involved in vitamin D metabolism in liver and kidney, and consequently affects vitamin D target genes levels. (orig.)

  4. Effects of depleted uranium after short-term exposure on vitamin D metabolism in rat

    International Nuclear Information System (INIS)

    Uranium is a natural radioactive heavy metal. Its toxicity has been demonstrated for different organs, including bone, kidney, liver and brain. Effects of an acute contamination by depleted uranium (DU) were investigated in vivo on vitamin D3 biosynthetic pathway. Rats received an intragastric administration of DU (204 mg/kg) and various parameters were studied either on day 1 or day 3 after contamination. Cytochrome P450 (CYP27A1, CYP2R1, CYP27B1, CYP24A1) enzymes involved in vitamin D metabolism and two vitamin D3-target genes (ECaC1, CaBP-D9K) were assessed by real time RT-PCR in liver and kidneys. CYP27A1 activity was measured in liver and vitamin D and parathyroid hormone (PTH) level were measured in plasma. In acute treated-rats, vitamin D level was increased by 62% and decreased by 68% in plasma, respectively at day 1 and at day 3, which paralleled with a concomitant decrease of PTH level (90%) at day 3. In liver, cyp2r1 mRNA level was increased at day 3. Cyp27a1 activity decreased at day 1 and increased markedly at day 3. In kidney, cyp27b1 mRNA was increased at days 1 and 3 (11- and 4-fold respectively). Moreover, ecac1 and cabp-d9k mRNA levels were increased at day 1 and decreased at day 3. This work shows for the first time that DU acute contamination modulates both activity and expression of CYP enzymes involved in vitamin D metabolism in liver and kidney, and consequently affects vitamin D target genes levels. (orig.)

  5. Radiation exposure of the public as a result of the present operations of Ranger Uranium Mines Pty Ltd

    International Nuclear Information System (INIS)

    Ranger Uranium Mines monitors ambient levels of ionising radiation in accordance with the Code of Practice on Radiation Protection in the Mining and Milling of Radioactive Ores 1980. The radionuclides of interest are: U-238, Th-230, Ra-226, Pb-210, Po-210 and Rn-222 daughters (RnD). The aerial pathway appears to be the critical pathway for transfer of radioactive contaminants to the local population. The average annual effective dose equivalent rate to a member of the critical group from inhalation of long-lived radioactive dust is 0.22 +- 0.10 mSv/y, about 22 times below the limit of 5 mSv/y. No experimental evidence was found for any overall increase of exposure of the public due to consumption of bush food items collected in the vicinity of the Ranger site. The average exposure of the critical group member to RnD is likely to be 2.1 +- 3.1 mWLM/y, or 200 times below the annual limit of 0.4 WLM

  6. Chronic neonicotinoid pesticide exposure and parasite stress differentially affects learning in honeybees and bumblebees.

    Science.gov (United States)

    Piiroinen, Saija; Goulson, Dave

    2016-04-13

    Learning and memory are crucial functions which enable insect pollinators to efficiently locate and extract floral rewards. Exposure to pesticides or infection by parasites may cause subtle but ecologically important changes in cognitive functions of pollinators. The potential interactive effects of these stressors on learning and memory have not yet been explored. Furthermore, sensitivity to stressors may differ between species, but few studies have compared responses in different species. Here, we show that chronic exposure to field-realistic levels of the neonicotinoid clothianidin impaired olfactory learning acquisition in honeybees, leading to potential impacts on colony fitness, but not in bumblebees. Infection by the microsporidian parasiteNosema ceranaeslightly impaired learning in honeybees, but no interactive effects were observed.Nosemadid not infect bumblebees (3% infection success). Nevertheless,Nosema-treated bumblebees had a slightly lower rate of learning than controls, but faster learning in combination with neonicotinoid exposure. This highlights the potential for complex interactive effects of stressors on learning. Our results underline that one cannot readily extrapolate findings from one bee species to others. This has important implications for regulatory risk assessments which generally use honeybees as a model for all bees. PMID:27053744

  7. Chronic toxicity of heavy fuel oils to fish embryos using multiple exposure scenarios.

    Science.gov (United States)

    Martin, Jonathan D; Adams, Julie; Hollebone, Bruce; King, Thomas; Brown, R Stephen; Hodson, Peter V

    2014-03-01

    The chronic toxicity to rainbow trout (Oncorhynchus mykiss) embryos of heavy fuel oil (HFO) 6303, weathered HFO 6303, HFO 7102, and medium South American (MESA) crude oil was assessed by different exposure regimes. These included water accommodated fractions (WAF; water in contact with floating oil), chemically enhanced WAF (CEWAF; oil dispersed with Corexit 9500), and effluent from columns of gravel coated with stranded oil. Heavy fuel oil WAF was nontoxic and did not contain detectable concentrations of hydrocarbons, likely because the high density and viscosity of HFO prevented droplet formation. In contrast, chemically dispersed HFO and effluent from columns of stranded HFO contained measurable concentrations of alkyl polycyclic aromatic hydrocarbons (PAH), coincident with embryo toxicity. These exposure regimes enhanced the surface area of oil in contact with water, facilitating oil-water partitioning of hydrocarbons. Heavy fuel oil was consistently more toxic to fish than crude oil and the rank order of alkyl PAH concentrations in whole oil were sufficient to explain the rank order of toxicity, regardless of exposure method. Thus, the propensity of HFO to sink and strand in spawning shoals creates a long-term risk to developing fish because of the sustained release of PAHs from HFO to interstitial waters. Further, PAH monitoring is key to accurate risk assessment. PMID:24464524

  8. Histopathologic alterations associated with global gene expression due to chronic dietary TCDD exposure in juvenile zebrafish.

    Directory of Open Access Journals (Sweden)

    Qing Liu

    Full Text Available The goal of this project was to investigate the effects and possible developmental disease implication of chronic dietary TCDD exposure on global gene expression anchored to histopathologic analysis in juvenile zebrafish by functional genomic, histopathologic and analytic chemistry methods. Specifically, juvenile zebrafish were fed Biodiet starter with TCDD added at 0, 0.1, 1, 10 and 100 ppb, and fish were sampled following 0, 7, 14, 28 and 42 d after initiation of the exposure. TCDD accumulated in a dose- and time-dependent manner and 100 ppb TCDD caused TCDD accumulation in female (15.49 ppb and male (18.04 ppb fish at 28 d post exposure. Dietary TCDD caused multiple lesions in liver, kidney, intestine and ovary of zebrafish and functional dysregulation such as depletion of glycogen in liver, retrobulbar edema, degeneration of nasal neurosensory epithelium, underdevelopment of intestine, and diminution in the fraction of ovarian follicles containing vitellogenic oocytes. Importantly, lesions in nasal epithelium and evidence of endocrine disruption based on alternatively spliced vasa transcripts are two novel and significant results of this study. Microarray gene expression analysis comparing vehicle control to dietary TCDD revealed dysregulated genes involved in pathways associated with cardiac necrosis/cell death, cardiac fibrosis, renal necrosis/cell death and liver necrosis/cell death. These baseline toxicological effects provide evidence for the potential mechanisms of developmental dysfunctions induced by TCDD and vasa as a biomarker for ovarian developmental disruption.

  9. Chronic exposure to neonicotinoids increases neuronal vulnerability to mitochondrial dysfunction in the bumblebee (Bombus terrestris).

    Science.gov (United States)

    Moffat, Christopher; Pacheco, Joao Goncalves; Sharp, Sheila; Samson, Andrew J; Bollan, Karen A; Huang, Jeffrey; Buckland, Stephen T; Connolly, Christopher N

    2015-05-01

    The global decline in the abundance and diversity of insect pollinators could result from habitat loss, disease, and pesticide exposure. The contribution of the neonicotinoid insecticides (e.g., clothianidin and imidacloprid) to this decline is controversial, and key to understanding their risk is whether the astonishingly low levels found in the nectar and pollen of plants is sufficient to deliver neuroactive levels to their site of action: the bee brain. Here we show that bumblebees (Bombus terrestris audax) fed field levels [10 nM, 2.1 ppb (w/w)] of neonicotinoid accumulate between 4 and 10 nM in their brains within 3 days. Acute (minutes) exposure of cultured neurons to 10 nM clothianidin, but not imidacloprid, causes a nicotinic acetylcholine receptor-dependent rapid mitochondrial depolarization. However, a chronic (2 days) exposure to 1 nM imidacloprid leads to a receptor-dependent increased sensitivity to a normally innocuous level of acetylcholine, which now also causes rapid mitochondrial depolarization in neurons. Finally, colonies exposed to this level of imidacloprid show deficits in colony growth and nest condition compared with untreated colonies. These findings provide a mechanistic explanation for the poor navigation and foraging observed in neonicotinoid treated bumblebee colonies. PMID:25634958

  10. Kalrn promoter usage and isoform expression respond to chronic cocaine exposure

    Directory of Open Access Journals (Sweden)

    Ma Xin-Ming

    2011-02-01

    Full Text Available Abstract Background The long-term effects of cocaine on behavior are accompanied by structural changes in excitatory glutamatergic synapses onto the medium spiny neurons of the striatum. The Kalrn gene encodes several functionally distinct isoforms; these multidomain guanine nucleotide exchange factors (GEFs contain additional domains known to interact with phosphatidylinositides as well as with a number of different proteins. Through their activation of Rho proteins and their interactions with other proteins, the different Kalirin isoforms affect cytoskeletal organization. Chronic exposure of adult male rodents to cocaine increases levels of Kalirin 7 in the striatum. When exposed chronically to cocaine, mice lacking Kalirin 7, the major adult isoform, fail to show an increase in dendritic spine density in the nucleus accumbens, show diminished place preference for cocaine, and exhibit increased locomotor activity in response to cocaine. Results The use of alternate promoters and 3'-terminal exons of the mouse Kalrn gene were investigated using real-time quantitative polymerase chain reaction. While the two most distal full-length Kalrn promoters are used equally in the prefrontal cortex, the more proximal of these promoters accounts for most of the transcripts expressed in the nucleus accumbens. The 3'-terminal exon unique to the Kalirin 7 isoform accounts for a greater percentage of the Kalrn transcripts in prefrontal cortex than in nucleus accumbens. Western blot analyses confirmed these differences. Chronic cocaine treatment increases usage of the promoter encoding the Δ-Kalirin isoforms but does not alter full-length Kalirin promoter usage. Usage of the 3'-terminal exon unique to Kalirin 7 increases following chronic cocaine exposure. Conclusions Kalrn promoter and 3'-terminal exon utilization are region-specific. In the nucleus accumbens, cocaine-mediated alterations in promoter usage and 3'-terminal exon usage favor expression of

  11. Chronic neonatal nicotine exposure increases excitation in the young adult rat hippocampus in a sex-dependent manner

    OpenAIRE

    Damborsky, Joanne C.; Griffith, William H.; Ursula H Winzer-Serhan

    2011-01-01

    Smoking during pregnancy exposes the fetus to nicotine, resulting in nicotine-stimulated neurotransmitter release. Recent evidence suggests that the hippocampus develops differently in males and females with delayed maturation in males. We show that chronic nicotine exposure during the first postnatal week has sex-specific long-term effects. Neonatal rat pups were chronically treated with nicotine (6 mg/kg/day) (CNN) from postnatal day 1 to 7 or milk only (Controls), and hippocampal slices we...

  12. Long-term consequences of chronic fluoxetine exposure on the expression of myelination-related genes in the rat hippocampus.

    Science.gov (United States)

    Kroeze, Y; Peeters, D; Boulle, F; van den Hove, D L A; van Bokhoven, H; Zhou, H; Homberg, J R

    2015-01-01

    The selective serotonin reuptake inhibitor (SSRI) fluoxetine is widely prescribed for the treatment of symptoms related to a variety of psychiatric disorders. After chronic SSRI treatment, some symptoms remediate on the long term, but the underlying mechanisms are not yet well understood. Here we studied the long-term consequences (40 days after treatment) of chronic fluoxetine exposure on genome-wide gene expression. During the treatment period, we measured body weight; and 1 week after treatment, cessation behavior in an SSRI-sensitive anxiety test was assessed. Gene expression was assessed in hippocampal tissue of adult rats using transcriptome analysis and several differentially expressed genes were validated in independent samples. Gene ontology analysis showed that upregulated genes induced by chronic fluoxetine exposure were significantly enriched for genes involved in myelination. We also investigated the expression of myelination-related genes in adult rats exposed to fluoxetine at early life and found two myelination-related genes (Transferrin (Tf) and Ciliary neurotrophic factor (Cntf)) that were downregulated by chronic fluoxetine exposure. Cntf, a neurotrophic factor involved in myelination, showed regulation in opposite direction in the adult versus neonatally fluoxetine-exposed groups. Expression of myelination-related genes correlated negatively with anxiety-like behavior in both adult and neonatally fluoxetine-exposed rats. In conclusion, our data reveal that chronic fluoxetine exposure causes on the long-term changes in expression of genes involved in myelination, a process that shapes brain connectivity and contributes to symptoms of psychiatric disorders. PMID:26393488

  13. Effects of Acute and Chronic Heavy Metal (Cu, Cd, and Zn) Exposure on Sea Cucumbers (Apostichopus japonicus)

    OpenAIRE

    Li, Li; Tian, Xiangli; Yu, Xiao; Dong, Shuanglin

    2016-01-01

    Acute and chronic toxicity tests were conducted with sea cucumber (Apostichopus japonicus) exposed to heavy metals. Acute toxicity values (96 h LC50) were 2.697, 0.133, and 1.574 mg L−1 for Zn, Cu, and Cd, respectively, and were ranked in order of toxicity: Cu > Cd > Zn. Under chronic metal exposure the specific growth rates of sea cucumbers decreased with the increase of metal concentration for all the three metals. After acute metal exposure, the oxygen consumption rate (OCR) decreased. The...

  14. In vivo effects of chronic contamination with depleted uranium on CYP3A and associated nuclear receptors PXR and CAR in the rat

    International Nuclear Information System (INIS)

    In addition to its natural presence at high concentrations in some areas, uranium has several civilian and military applications that could cause contamination of human populations, mainly through chronic ingestion. Reports describe the accumulation of this radionuclide in some organs (including the bone, kidney, and liver) after acute or chronic contamination and show that it produces chemical or radiological toxicity or both. The literature is essentially devoid of information about uranium-related cellular and molecular effects on metabolic functions such as xenobiotic detoxification. The present study thus evaluated rats chronically exposed to depleted uranium in their drinking water (1 mg/(rat day)) for 9 months. Our specific aim was to evaluate the hepatic and extrahepatic mRNA expression of CYP3A1/A2, CYP2B1, and CYP1A1 as well as of the nuclear receptors PXR, CAR, and RXR in these rats. CYP3A1 mRNA expression was significantly higher in the brain (200%), liver (300%), and kidneys (900%) of exposed rats compared with control rats, while CYP3A2 mRNA levels were higher in the lungs (300%) and liver (200%), and CYP2B1 mRNA expression in the kidneys (300%). Expression of CYP1A1 mRNA did not change significantly during this study. PXR mRNA levels increased in the brain (200%), liver (150%), and kidneys (200%). Uranium caused CAR mRNA expression in the lungs to double. Expression of RXR mRNA did not change significantly in the course of this study, nor did the hepatic activity of CYP2C, CYP3A, CYP2A, or CYP2B. Uranium probably affects the expression of drug-metabolizing CYP enzymes through the PXR and CAR nuclear receptors. These results suggest that the stimulating effect of uranium on these enzymes might lead to hepatic or extrahepatic toxicity (or both) during drug treatment and then affect the entire organism

  15. Assessing Cumulative Thermal Stress in Fish During Chronic Exposure to High Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Bevelhimer, M.S.; Bennett, W.R.

    1999-11-14

    As environmental laws become increasingly protective, and with possible future changes in global climate, thermal effects on aquatic resources are likely to receive increasing attention. Lethal temperatures for a variety of species have been determined for situations where temperatures rise rapidly resulting in lethal effects. However, less is known about the effects of chronic exposure to high (but not immediately lethal) temperatures and even less about stress accumulation during periods of fluctuating temperatures. In this paper we present a modeling framework for assessing cumulative thermal stress in fish. The model assumes that stress accumulation occurs above a threshold temperature at a rate depending on the degree to which the threshold is exceeded. The model also includes stress recovery (or alleviation) when temperatures drop below the threshold temperature as in systems with large daily variation. In addition to non-specific physiological stress, the model also simulates thermal effects on growth.

  16. [Influence of chronic lead exposure on resistence to bacterial infection (author's transl)].

    Science.gov (United States)

    Ewers, U; Weisser, L; Wegner, A

    1980-01-01

    Suppression by lead of resistance to bacterial or viral infections has been reported by several authors. We have studied, if a decrease of resistance to bacterial infection could be evaluated at blood lead concentrations (PbB), which correspond to the upper levels of environmental or occupational lead exposure regarded as tolerable (PbB = 35 resp. 60 microgram/100 ml). NMRI mice were chronically exposed to lead by feeding with lead acetate containing diets and given a challenge with Salmonella typhimurium. No increase of susceptibility to bacterial infection could be demonstrated at PbB 100 microgram/100 g, however, an increase of lethality and a decrease of 50% survival times could be observed after bacterial infection. PMID:6999813

  17. Regional alterations of brain biogenic amines in young rats following chronic lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    Dubas, T.C.; Stevenson, A.; Singhal, R.L.; Hrdina, P.D.

    1978-02-01

    An examination was made of neurochemical changes that occur in discrete brain regions of rats that have been chronically exposed to low levels of lead from birth, in order to provide further information on the involvement of brain biogenic amines in lead-induced neurotoxicity. Results indicate a relationship between exposure to lead and alterations in the brain levels of various putative neurotransmitters. However, changes in the functional activity of the neurotransmitter may not be adequately reflected in the change of its steady-state levels or may occur even in the absence of any changes in the actual concentrations. Lead may influence central neurotransmitter function by affecting one or several of the processes involved in the synthesis, release and/or disposition of biogenic amines.

  18. Chronic estrogen exposure maintains elevated levels of progesterone receptor mRNA in guinea pig hypothalamus.

    Science.gov (United States)

    Bayliss, D A; Millhorn, D E

    1991-05-01

    We performed in situ hybridization on hypothalamic sections from ovariectomized guinea pig using a cocktail of three 35S-labeled oligonucleotides complementary to mammalian progesterone receptor (PR) cDNA. PR mRNA was readily detected in hypothalamic neurons from guinea pigs pretreated with 17 beta-estradiol benzoate (E2B), but not from animals which did not receive supplemental E2B. The distribution of PR mRNA-containing cells corresponded well with previous localizations of PR in guinea pig. In contrast to earlier reports of E2B regulation of PR mRNA in rat hypothalamus, however, we found that PR mRNA remained elevated during chronic exposure to E2B (up to 10 days) in guinea pig. PMID:2072827

  19. Murine pulmonary responses after sub-chronic exposure to aluminum oxide-based nanowhiskers

    Directory of Open Access Journals (Sweden)

    Adamcakova-Dodd Andrea

    2012-06-01

    Full Text Available Abstract Background Aluminum oxide-based nanowhiskers (AO nanowhiskers have been used in manufacturing processes as catalyst supports, flame retardants, adsorbents, or in ceramic, metal and plastic composite materials. They are classified as high aspect ratio nanomaterials. Our aim was to assess in vivo toxicity of inhaled AO nanowhisker aerosols. Methods Primary dimensions of AO nanowhiskers specified by manufacturer were 2–4 nm x 2800 nm. The aluminum content found in this nanomaterial was 30% [mixed phase material containing Al(OH3 and AlOOH]. Male mice (C57Bl/6 J were exposed to AO nanowhiskers for 4 hrs/day, 5 days/wk for 2 or 4 wks in a dynamic whole body exposure chamber. The whiskers were aerosolized with an acoustical dry aerosol generator that included a grounded metal elutriator and a venturi aspirator to enhance deagglomeration. Average concentration of aerosol in the chamber was 3.3 ± 0.6 mg/m3 and the mobility diameter was 150 ± 1.6 nm. Both groups of mice (2 or 4 wks exposure were necropsied immediately after the last exposure. Aluminum content in the lung, heart, liver, and spleen was determined. Pulmonary toxicity assessment was performed by evaluation of bronchoalveolar lavage (BAL fluid (enumeration of total and differential cells, total protein, activity of lactate dehydrogenase [LDH] and cytokines, blood (total and differential cell counts, lung histopathology and pulmonary mechanics. Results Following exposure, mean Al content of lungs was 0.25, 8.10 and 15.37 μg/g lung (dry wt respectively for sham, 2 wk and 4 wk exposure groups. The number of total cells and macrophages in BAL fluid was 2-times higher in animals exposed for 2 wks and 6-times higher in mice exposed for 4 wks, compared to shams (p p  Conclusions Sub-chronic inhalation exposures to aluminum-oxide based nanowhiskers induced increased lung macrophages, but no inflammatory or toxic responses were observed.

  20. Associations between Chronic Community Noise Exposure and Blood Pressure at Rest and during Acute Noise and Non-Noise Stressors among Urban School Children in India

    OpenAIRE

    Bang Hyun Kim; Evans, Gary W.; Stephen J. Lepore; Bhaskar Shejwal

    2010-01-01

    The present study builds on prior research that has examined the association between children’s chronic exposure to community noise and resting blood pressure and blood pressure dysregulation during exposure to acute stressors. A novel contribution of the study is that it examines how chronic noise exposure relates to blood pressure responses during exposure to both noise and non-noise acute stressors. The acute noise stressor was recorded street noise and the non-noise stressor was mental ar...

  1. Chronic health effects of sulphur mustard exposure with special reference to Iranian veterans

    Directory of Open Access Journals (Sweden)

    B Balali-Mood

    2008-01-01

    Full Text Available The widespread use of sulphur mustard (SM as an incapacitating chemical warfare agent in the past century has proved its long-lasting toxic effects. It may also be used as a chemical terrorist agent. Therefore, all health professionals should have sufficient knowledge and be prepared for any such chemical attack. SM exerts direct toxic effects on the eyes, skin, and respiratory tissue, with subsequent systemic action on the nervous, immunological, haematological, digestive, and reproductive systems. SM is an alkylating agent that affects DNA synthesis, and, thus, delayed complications have been seen since the First World War. Cases of malignancies in the target organs, particularly in haematopoietic, respiratory, and digestive systems, have been reported. Important delayed respiratory complications include chronic bronchitis, bronchiectasis, frequent bronchopneumonia, and pulmonary fibrosis, all of which tend to deteriorate with time. Severe dry skin, delayed keratitis, and reduction of natural killer cells with subsequent increased risk of infections and malignancies are also among the most distressing long-term consequences of SM intoxication. However, despite a lot of research over the past decades on Iranian veterans, there are still major gaps in the SM literature. Immunological and neurological dysfunction, as well as the relationship between SM exposure and mutagenicity, carcinogenicity, and teratogenicity are important fields that require further studies, particularly on Iranian veterans with chronic health effects of SM poisoning. There is also a paucity of information on the medical management of acute and delayed toxic effects of SM poisoning—a subject that greatly challenges health care specialists.

  2. Chronic Arsenic Exposure-Induced Oxidative Stress is Mediated by Decreased Mitochondrial Biogenesis in Rat Liver.

    Science.gov (United States)

    Prakash, Chandra; Kumar, Vijay

    2016-09-01

    The present study was executed to study the effect of chronic arsenic exposure on generation of mitochondrial oxidative stress and biogenesis in rat liver. Chronic sodium arsenite treatment (25 ppm for 12 weeks) decreased mitochondrial complexes activity in rat liver. There was a decrease in mitochondrial superoxide dismutase (MnSOD) activity in arsenic-treated rats that might be responsible for increased protein and lipid oxidation as observed in our study. The messenger RNA (mRNA) expression of mitochondrial and nuclear-encoded subunits of complexes I (ND1 and ND2) and IV (COX I and COX IV) was downregulated in arsenic-treated rats only. The protein and mRNA expression of MnSOD was reduced suggesting increased mitochondrial oxidative damage after arsenic treatment. There was activation of Bax and caspase-3 followed by release of cytochrome c from mitochondria suggesting induction of apoptotic pathway under oxidative stress. The entire phenomenon was associated with decrease in mitochondrial biogenesis as evident by decreased protein and mRNA expression of nuclear respiratory factor 1 (NRF-1), nuclear respiratory factor 2 (NRF-2), peroxisome proliferator activator receptor gamma-coactivator 1α (PGC-1α), and mitochondrial transcription factor A (Tfam) in arsenic-treated rat liver. The results of the present study indicate that arsenic-induced mitochondrial oxidative stress is associated with decreased mitochondrial biogenesis in rat liver that may present one of the mechanisms for arsenic-induced hepatotoxicity. PMID:26767369

  3. Effect of head-only sub-chronic GSM exposure on spatial memory of rats

    International Nuclear Information System (INIS)

    Full text: Introduction: Low power electromagnetic fields (EMF) are suspected to produce deficit memory in rats. The study of Dubreuil et al (2003) showed that a short-term (10-15 days) exposure 'head-only' to GSM 900 MHz radio frequencies does not produce a deficit memory in adult rats. The aim of our experiment was to determine if head-only sub-chronic exposure (2 months) of rats to GSM signal for 45 min at a SAR = 1.5 W/Kg and for 15 min at 6 W/Kg induce deficit in spatial memory of rats in radial maze test. Materials and methods: Exposure system: Animals were placed in Plexiglas rockets with an individual loop antenna placed above the rat's head. Four animals were exposed at the time. Loop antennas were connected to a generator and emitted a GSM signal (900 MHz, pulsed at 217 Hz, 1/8 duty factor) 5 days / week for 8 weeks. Experimental group: 30 Sprague-Dawley male rats were randomly assigned to 5 different groups: a) 6 rats exposed 15 min at SAR = 6 W/Kg; b) 6 rats exposed 45 min at SAR = 1.5 W/g; c) 6 rats sham controls (3 for 5 min and 3 for 45 min, SAR = 0 W/Kg); d) 6 rats without any treatment and manipulation (cage control); e) 6 rats were injected (i.p) S.B.H 0.1 mg/Kg (Sigma Aldrich) as positive control group. Behavioural procedure: The radial maze protocol consists of two consecutive phases: the training task (10 days) and the test task (8 days). In the first phase, rats were trained to visit the 8 arms of the maze without returning to an arm already visited. In the second phase (8 days), a 45-min intra-trial delay was introduced after four visited arms. After the intra-delay, the rat was placed in the maze to finish the test task, which is visiting four other arms he had not visited. During the training task, exposure took place before the behavioural task. During the test task, exposure or sham-exposure took place during the intra-delay. Results and discussion: In all experiments, performance of exposed rats (1.5 and 6 W/Kg) was compared with that of

  4. Effects of chronic aluminum exposure on learning and memory and brain-derived nerve growth factor in rats

    Institute of Scientific and Technical Information of China (English)

    潘宝龙

    2013-01-01

    Objective To investigate the effects of chronic aluminum exposure on the learning and memory abilities and brain-derived nerve growth factor (BDNF) in SpragueDawley (SD) rats.Methods Thirty-two male SD rats were randomly and equally divided into 4 groups:control group and high-,middle-,and low-dose exposure groups.The rats in high-,middle-,and low-dose expo-

  5. Chronic exposure to chlorpyrifos reveals two modes of action in the springtail Folsomia candida

    International Nuclear Information System (INIS)

    Organophosphates are popular insecticides, but relatively little is known about their chronic effects on ecologically relevant endpoints. In this paper, we examine a life-cycle experiment with the springtail Folsomia candida, exposed via food to chlorpyrifos (CPF). The results for all endpoints (survival, growth and reproduction) were analyzed using the DEBtox model. Growth was unaffected by CPF, even at concentrations causing severe effects on survival and reproduction. Model analysis suggests that CPF directly affects the process of egg production. For the short-term response (45 days), this single mode of action accurately agreed with the data. However, the full data set (120 days) revealed a dose-related decrease in reproduction at low concentrations after prolonged exposure, not covered by the same mechanism. It appears that CPF interacts with senescence by increasing oxidative damage. This assumption fits the data well, but has little consequences for the predicted response at the population level. - Exposure to chlorpyrifos in food affects reproduction in springtails according to two distinct toxic mechanisms

  6. Chronic exposure to gamma radiation of wild populations of meadow voles (Microtus pennsylvanicus)

    International Nuclear Information System (INIS)

    Free-ranging, wild meadow voles (Microtus pennsylvanicus) were exposed to gamma radiation from a 137Cs irradiator in a series of experiments conducted on six 1-ha meadows within a mixed deciduous forest in Manitoba, Canada. Over a period of 1-1.5 years in each of three experiments, vole populations were monitored with capture-mark-release techniques at nominal exposure rates of 200x, 9000x and 40,000x background. No effects on population or individual characteristics were detected up to the highest exposure rate (81 mGy/d). At this level, third generation voles were monitored up to a lifetime dose of about 5.7 Gy, at a measured dose rate of 44 mGy/d. Smaller numbers of overwintered animals survived and reproduced normally at doses up to 10 Gy. These results are discussed in terms of low-LET, external chronic radiation effects on rodents in the laboratory and the field, relative to current views on appropriate benchmarks for the protection of biota

  7. Response of tibialis anterior tendon to a chronic exposure of stretch-shortening cycles: age effects

    Directory of Open Access Journals (Sweden)

    Baker Brent B

    2009-06-01

    Full Text Available Abstract Background The purpose of the current study was to investigate the effects of aging on tendon response to repetitive exposures of stretch-shortening cycles (SSC's. Methods The left hind limb from young (3 mo, N = 4 and old (30 mo, N = 9 male Fisher 344 × Brown Norway rats were exposed to 80 maximal SSCs (60 deg/s, 50 deg range of motion 3x/week for 4.5 weeks in vivo. After the last exposure, tendons from the tibialis anterior muscle were isolated, stored at -80°C, and then tested using a micro-mechanical testing machine. Deformation of each tendon was evaluated using both relative grip-to-grip displacements and reference marks via a video system. Results At failure, the young control tendons had higher strain magnitude than the young exposed (p Conclusion The chronic protocol enhanced the elastic stiffness of young tendon and the loads in both the young and old tendons. The old exposed tendons were found to exhibit higher load capacity than their younger counterparts, which differed from our initial hypothesis.

  8. [MORPHOFUNCTIONAL STATE OF BLOOD CELLS AFTER CHRONIC EXPOSURE OF THE PROTEIN KINASES INHIBITOR MALEIMIDE DERIVATIVE].

    Science.gov (United States)

    Byelinska, I V; Lynchak, O V; Tsyvinska, S M; Rybalchenko, V K

    2015-01-01

    The effect of the protein kinases inhibitor maleimide derivative (MI-1, 1-(4-Cl-benzyl)-3-Cl-4-(CF3-phenylamino)-1H-pyrrole-2,5-dione), inhibitor of VEGF-R1,2,3, FGF-R1, EGF-R(h), PDK1, Src(h), Syk(h), YES, ZAP70 et al. with antineoplastic activity, on blood cells parameters of rats after chronic exposure has been studied. Administration of MI-1 at doses 0.027 and 2.7 mg/kg (suppress colon carcinogenesis) for 20 and 26 weeks does not affect the morphofunctional state of red blood cells in healthy rats. This is confirmed by the lack of differences in the concentration of hemoglobin in blood, red blood cells count, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration, hematocrit and mean corpuscular volume, and the number of reticulocytes in blood after 20 and 26 weeks of exposure compared with the control group. MI-1 at indicated doses does not influence total leukocytes count and content (eosinophilic and neutrophilic granulocytes, lymphocytes, monocytes) and does not inhibit thrombocytopoiesis (platelet count remains unchanged). No negative effect of MI-1 on hematopoiesis is not limited (by the hemopoietic system) use of this compound as a potential antitumor drug PMID:26552308

  9. Effects of Sub-chronic Aluminum Exposure on Renal Structure in Rats

    Institute of Scientific and Technical Information of China (English)

    Li Yan-fei; Liu Jian-yu; Cao Zheng

    2015-01-01

    To investigate the effects of aluminum (Al) exposure on renal structure of rats, 60 Wistar rats were randomly divided into four treatment groups and were orally exposed to 0 (control group, GC), 64.18 (low-dose group, GL), 128.36 (middle-dose group, GM), and 256.72 (high-dose group, GH) mg• kg-1 BW AlCl3 in drinking water for 120 days. The body weight of different rats was recorded, the kidney pathologic structure and the ultrastructure were observed. The results showed that the body weight of different rats was markedly lower in Al-treated rats than those in GC (P<0.05;P<0.01). After masson staining, the collagen was deposited in the renal interstitium and aggravated with Al dose increases in Al-treated rats. Under electron microscope, the infolding of the plasma membrane was slight swollen, the mitochondrion was abundant with different sizes, the mitochondrion cristae was fused, the microvillus was swollen and fused in GH. Our findings indicated that sub-chronic Al exposure slowed the weight of rats and caused the kidney pathologic damage in rats.

  10. Pulmonary and hepatic injury after sub-chronic exposure to sublethal doses of microcystin-LR.

    Science.gov (United States)

    Carvalho, Giovanna Marcella Cavalcante; Oliveira, Vinícius Rosa; Casquilho, Natália Vasconcelos; Araujo, Andressa Cristine Pereira; Soares, Raquel Moraes; Azevedo, Sandra Maria F O; Pires, Karla Maria Pereira; Valença, Samuel Santos; Zin, Walter Araujo

    2016-03-15

    We had previously shown that microcystin-LR (MCLR) could induce lung and liver inflammation after acute exposure. The biological outcomes following prolonged exposure to MCLR, although more frequent, are still poorly understood. Thus, we aimed to verify whether repeated doses of MCLR could damage lung and liver and evaluate the dose-dependence of the results. Male Swiss mice received 10 intraperitoneal injections (i.p.) of distilled water (60 μL, CTRL) or different doses of MCLR (5 μg/kg, TOX5), 10 μg/kg (TOX10), 15 μg/kg (TOX15) and 20 μg/kg (TOX20) every other day. On the tenth injection respiratory mechanics (lung resistive and viscoelastic/inhomogeneous pressures, static elastance, and viscoelastic component of elastance) was measured. Lungs and liver were prepared for histology (morphometry and cellularity) and inflammatory mediators (KC and MIP-2) determination. All mechanical parameters and alveolar collapse were significantly higher in TOX5, 10, 15 and 20 than CTRL, but did not differ among them. Lung inflammatory cell content increased dose-dependently in all TOX groups in relation to CTRL, being TOX20 the largest. The production of KC was increased in lung and liver homogenates. MIP-2 increased in the liver of all TOX groups, but in lung homogenates it was significantly higher only in TOX20 group. All TOX mice livers showed steatosis, necrosis, inflammatory foci and a high degree of binucleated hepatocytes. In conclusion, sub-chronic exposure to MCLR damaged lung and liver in all doses, with a more important lung inflammation in TOX20 group. PMID:26844922

  11. Chronic exposure to low-levels of lead in the rat: biochemical and behavioural changes

    International Nuclear Information System (INIS)

    The prevalence of lead in the environment is a cause of continuing toxicology concern and there have been numerous human and animal studies to examine more thoroughly the possible consequences of exposure to this ecotoxicant. Because lead is highly toxic to the developing central nervous system, increasing concern over the rise in the lead content in the environment has been expressed. These concerns seem appropriate since more recent clinical studies have shown that prolonged exposure of children to so called 'subclinical' concentrations of lead may be associated with behavioural disorders, learning disabilities and mental retardation. Moreover, animal studies have shown that chronic perinatal low-level lead exposure elicits alterations in both learned and spontaneous behavioural patterns in the absence of typical outward signs of lead-induced neurological toxicity. No study however could relate behavioural changes to specific alterations in neurochemisty. The aim of this study was therefore to expose rats, in different stages of their development, to low-levels of lead in order to induce behavioural disorders and correlate latter with possible neurochemical changes. In accordance with the general aims of the study, the structuring of the thesis is as follows: (a) a discussion of the neurotransmitters in the brain in order to describe the different systems which have been investigated; (b) a review of appropriate literature regarding the kinetics, toxodynamics and neurotoxicity of lead and (c) a summary of the methods employed in the study. The following results are presented: (d) the effects of lead treatment on physical development of the rats; (e) the induction of behavioural supersensitivity and (f) the effects lead has on central receptors

  12. Quantitative Neuropathology Associated with Chronic Manganese Exposure in South African Mine Workers

    Science.gov (United States)

    Gonzalez-Cuyar, Luis F.; Nelson, Gill; Criswell, Susan R.; Ho, Pokuan; Lonzanida, Jaymes A.; Checkoway, Harvey; Seixas, Noah; Gelman, Benjamin B.; Evanoff, Bradley A.; Murray, Jill; Zhang, Jing; Racette, Brad A.

    2014-01-01

    Manganese (Mn) is a common neurotoxicant associated with a clinical syndrome that includes signs and symptoms referable to the basal ganglia. Despite many advances in understanding the pathophysiology of Mn neurotoxicity in humans, with molecular and structural imaging techniques, only a few case reports describe the associated pathological findings, and all are in symptomatic subjects exposed to relatively high-level Mn. We performed an exploratory, neurohistopathological study to investigate the changes in the corpus striatum (caudate nucleus, putamen, and globus pallidus) associated with chronic low-level Mn exposure in South African Mn mine workers. Immunohistochemical techniques were used to quantify cell density of neuronal and glial components of the corpus striatum in eight South African Mn mine workers without clinical evidence of a movement disorder and eight age-race-gender matched, non-Mn mine workers. There was higher mean microglia density in Mn mine workers than non-Mn mine workers in the globus pallidus external and internal segments [GPe: 1.33 and 0.87 cells per HPF, respectively (p=0.064); GPi: 1.37 and 0.99 cells per HPF, respectively (p=0.250)]. The number of years worked in the Mn mines was significantly correlated with microglial density in the GPi (Spearman's rho 0.886; p=0.019). The ratio of astrocytes to microglia in each brain region was lower in the Mn mine workers than the non-Mn mine workers in the caudate (7.80 and 14.68; p=0.025), putamen (7.35 and 11.11; p=0.117), GPe (10.60 and 16.10; p=0.091) and GPi (9.56 and 12.42; p=0.376). Future studies incorporating more detailed occupational exposures in a larger sample of Mn mine workers will be needed to demonstrate an etiologic relationship between Mn exposure and these pathological findings. PMID:24374477

  13. Effects of chronic exposure to ionising radiation in the Pacific oyster Crassostrea gigas

    International Nuclear Information System (INIS)

    The Cotentin peninsula (Normandy, France) hosts nuclear industry facilities which operate with controlled discharges of radionuclides in the marine environment. Compared to natural radioactivity, the increase by artificial radionuclides is small but constant. As a consequence, marine species are chronically exposed to low additional doses of ionizing radiation (IR). The effects of chronic exposure to radionuclides were investigated in early stages of development of the Japanese oyster Crassostrea gigas. On the basis of literature, mollusks are expected to be particularly resistant to acute IR (UNSCEAR, 1996. Sources and effects of ionizing radiation. Report to the General Assembly, with Scientific Annex. 86 p). Two different chronic exposure conditions consisted in external (137Cs) and internal (241Am) irradiation for two weeks. Biological endpoints were analyzed in parallel at both the integrated (growth) and molecular (target stress gene expression) levels. To identify potential biological targets of IR, oysters were first exposed to very high dose rates and radionuclide activities with the perspective to reduce the levels and to derive dose-response curves. Although the initial exposure levels (137Cs 30 000 μGy.h-1; 241Am 57 000 Bq.L-1) were many orders of magnitude higher than those encountered in the natural environment, no significant change in the measured parameters was observed. This result was surprising because data from the literature showed that exposure of mussel Mytilus edulis to 3H at lower doses rates (10-100 μGy.h-1) induced DNA damage in hemocytes (Jha et al., 2005. Impact of low doses of tritium on the marine mussel, Mytilus edulis: Genotoxic effects and tissue-specific bioconcentration. Mutation Research/Genetic Toxicology and Environmental Mutagenesis 586, 47-57). To understand this apparent discrepancy between those two filtering bivalves, a new experiment was performed to compare the response of oyster exposed to 3H in the same condition

  14. Effects of chronic exposure to ionising radiation in the Pacific oyster Crassostrea gigas

    Energy Technology Data Exchange (ETDEWEB)

    Fievet, B.; Devos, A.; Voiseux, C.; Leconte-Pradines, C. [Institut de Radioprotection et de Surete' Nucleaire (France); Dallas, L.; Jha, A. [University of Plymouth (United Kingdom)

    2014-07-01

    The Cotentin peninsula (Normandy, France) hosts nuclear industry facilities which operate with controlled discharges of radionuclides in the marine environment. Compared to natural radioactivity, the increase by artificial radionuclides is small but constant. As a consequence, marine species are chronically exposed to low additional doses of ionizing radiation (IR). The effects of chronic exposure to radionuclides were investigated in early stages of development of the Japanese oyster Crassostrea gigas. On the basis of literature, mollusks are expected to be particularly resistant to acute IR (UNSCEAR, 1996. Sources and effects of ionizing radiation. Report to the General Assembly, with Scientific Annex. 86 p). Two different chronic exposure conditions consisted in external ({sup 137}Cs) and internal ({sup 241}Am) irradiation for two weeks. Biological endpoints were analyzed in parallel at both the integrated (growth) and molecular (target stress gene expression) levels. To identify potential biological targets of IR, oysters were first exposed to very high dose rates and radionuclide activities with the perspective to reduce the levels and to derive dose-response curves. Although the initial exposure levels ({sup 137}Cs 30 000 μGy.h{sup -1}; {sup 241}Am 57 000 Bq.L{sup -1}) were many orders of magnitude higher than those encountered in the natural environment, no significant change in the measured parameters was observed. This result was surprising because data from the literature showed that exposure of mussel Mytilus edulis to {sup 3}H at lower doses rates (10-100 μGy.h{sup -1}) induced DNA damage in hemocytes (Jha et al., 2005. Impact of low doses of tritium on the marine mussel, Mytilus edulis: Genotoxic effects and tissue-specific bioconcentration. Mutation Research/Genetic Toxicology and Environmental Mutagenesis 586, 47-57). To understand this apparent discrepancy between those two filtering bivalves, a new experiment was performed to compare the response

  15. Oxidative stress responses induced by uranium exposure at low pH in leaves of Arabidopsis thaliana plants.

    Science.gov (United States)

    Saenen, Eline; Horemans, Nele; Vanhoudt, Nathalie; Vandenhove, Hildegarde; Biermans, Geert; van Hees, May; Wannijn, Jean; Vangronsveld, Jaco; Cuypers, Ann

    2015-12-01

    Anthropogenic activities have led to a widespread uranium (U) contamination in many countries. The toxic effects of U at the cellular level have mainly been investigated at a pH around 5.5, the optimal pH for hydroponically grown plants. However, since the speciation of U, and hence its toxicity, is strongly dependent on environmental factors such as the pH, it is important to investigate the effects of U at different environmentally relevant pH levels. Although U is poorly translocated from the roots to the shoots, resulting in a low U concentration in the leaves, it has been demonstrated that toxic effects in the leaves were already visible after 1 day exposure at pH 5.5, although only when exposed to relatively high U concentrations (100 μM). Therefore, the present study aimed to analyse the effects of different U concentrations (ranging from 0 to 100 μM) at pH 4.5 in leaves of Arabidopsis thaliana plants. Results indicate that U induces early senescence in A. thaliana leaves as was suggested by a decreased expression of CAT2 accompanied by an induction of CAT3 expression, a decreased CAT capacity and an increased lipid peroxidation. In addition, miRNA398b/c is involved in the regulation of the SOD response in the leaves. As such, an increased MIR398b/c expression was observed leading to a decreased transcript level of CSD1/2. Finally, the biosynthesis of ascorbate was induced after U exposure. This can point towards an important role for this metabolite in the scavenging of reactive oxygen species under U stress. PMID:26263174

  16. Induction of Oxidative Stress and Antioxidative Mechanisms in Arabidopsis thaliana after Uranium Exposure at pH 7.5.

    Science.gov (United States)

    Saenen, Eline; Horemans, Nele; Vanhoudt, Nathalie; Vandenhove, Hildegarde; Biermans, Geert; Van Hees, May; Wannijn, Jean; Vangronsveld, Jaco; Cuypers, Ann

    2015-01-01

    To evaluate the environmental impact of uranium (U) contamination, it is important to investigate the effects of U at ecologically relevant conditions. Since U speciation, and hence its toxicity, strongly depends on environmental pH, the present study aimed to investigate dose-dependent effects of U at pH 7.5. Arabidopsis thaliana plants (Mouse-ear Cress) were exposed for three days to different U concentrations at pH 7.5. In the roots, the increased capacities of ascorbate peroxidase and glutathione reductase indicate an important role for the ascorbate-glutathione cycle during U-induced stress. However, a significant decrease in the ascorbate redox state was observed after exposure to 75 and 100 µM U, indicating that those roots are severely stressed. In accordance with the roots, the ascorbate-glutathione cycle plays an important role in the antioxidative defence systems in A. thaliana leaves exposed to U at pH 7.5 as the ascorbate and glutathione biosynthesis were upregulated. In addition, small inductions of enzymes of the antioxidative defence system were observed at lower U concentrations to counteract the U-induced stress. However, at higher U concentrations it seems that the antioxidative defence system of the leaves collapses as reductions in enzyme activities and gene expression levels were observed. PMID:26042463

  17. Induction of Oxidative Stress and Antioxidative Mechanisms in Arabidopsis thaliana after Uranium Exposure at pH 7.5

    Directory of Open Access Journals (Sweden)

    Eline Saenen

    2015-06-01

    Full Text Available To evaluate the environmental impact of uranium (U contamination, it is important to investigate the effects of U at ecologically relevant conditions. Since U speciation, and hence its toxicity, strongly depends on environmental pH, the present study aimed to investigate dose-dependent effects of U at pH 7.5. Arabidopsis thaliana plants (Mouse-ear Cress were exposed for three days to different U concentrations at pH 7.5. In the roots, the increased capacities of ascorbate peroxidase and glutathione reductase indicate an important role for the ascorbate-glutathione cycle during U-induced stress. However, a significant decrease in the ascorbate redox state was observed after exposure to 75 and 100 µM U, indicating that those roots are severely stressed. In accordance with the roots, the ascorbate-glutathione cycle plays an important role in the antioxidative defence systems in A. thaliana leaves exposed to U at pH 7.5 as the ascorbate and glutathione biosynthesis were upregulated. In addition, small inductions of enzymes of the antioxidative defence system were observed at lower U concentrations to counteract the U-induced stress. However, at higher U concentrations it seems that the antioxidative defence system of the leaves collapses as reductions in enzyme activities and gene expression levels were observed.

  18. NOTCH1, HIF1A and other cancer-related proteins in lung tissue from uranium miners : variation by occupational exposure and subtype of lung cancer

    OpenAIRE

    Pesch, Beate; Casjens, Swaantje; Stricker, Ingo; Westerwick, Daniela; Taeger, Dirk; Rabstein, Sylvia; Wiethege, Thorsten; Tannapfel, Andrea; Brüning, Thomas; Johnen, Georg

    2012-01-01

    Background Radon and arsenic are established pulmonary carcinogens. We investigated the association of cumulative exposure to these carcinogens with NOTCH1, HIF1A and other cancer-specific proteins in lung tissue from uranium miners. Methodology/Principal Findings Paraffin-embedded tissue of 147 miners was randomly selected from an autopsy repository by type of lung tissue, comprising adenocarcinoma (AdCa), squamous cell carcinoma (SqCC), small cell lung cancer (SCLC), and cancer-free tissue....

  19. A novel mouse model for the study of the inhibitory effects of chronic ethanol exposure on direct bone formation

    Science.gov (United States)

    Excessive alcohol consumption has been reported to interfere with human bone homeostasis and repair in multiple ways. Previous studies have demonstrated that chronic ethanol exposure in the rat via an intragastric dietary delivery system inhibits direct bone formation during distraction osteogenesis...

  20. HEALTH RISKS FROM CHRONIC EXPOSURE TO ARSENIC VIA DRINKING WATER: FINDINGS FROM THE CLINICAL INVESTIGATIONS DATA IN INNER MONGOLIA, CHINA

    Science.gov (United States)

    Prior studies have reported a large number of arsenicism cases in the Mongolia Autonomous Region of China due to drinking arsenic-contaminated water with concentrations up to 1.8 mg/L. However, the endemic health risks from chronic exposure to arsenic in this population have not...

  1. Chronic ethanol exposure downregulates hepatic expression of pregnane X receptor and P450 3A11 in female ICR mice

    International Nuclear Information System (INIS)

    Pregnane X receptor (PXR) is a nuclear receptor that regulates cytochrome P450 3A (CYP3A) gene transcription in a ligand-dependent manner. Ethanol has been reported to be either an inducer or an inhibitor of CYP3A expression. In this study, we investigated the effects of chronic ethanol exposure on PXR and P450 3A11 gene expression in mouse liver. Female ICR mice were administered by gavage with different doses (1000, 2000 and 4000 mg/kg) of ethanol for up to 5 weeks. Hepatic PXR and P450 3A11 mRNA levels were measured using RT-PCR. Erythromycin N-demethylase (ERND) activity was used as an indicator of CYP3A protein expression. Results showed that chronic ethanol exposure markedly decreased hepatic PXR and P450 3A11 mRNA levels. Consistent with downregulation of P450 3A11 mRNA, chronic ethanol exposure significantly decreased ERND activity in a dose-dependent manner. Additional experiment showed that chronic ethanol exposure significantly increased plasma endotoxin level and hepatic CD14 and TLR-4 mRNA expression, all of which were blocked by elimination of Gram-negative bacteria and endotoxin with antibiotics. Correspondingly, pretreatment with antibiotics reversed the downregulation of PXR and P450 3A11 mRNA expression and ERND activity in mouse liver. Furthermore, the downregulation of hepatic PXR and P450 3A11 mRNA expression was significantly attenuated in mice pretreated with GdCl3, a selective Kupffer cell toxicant. GdCl3 pretreatment also significantly attenuated chronically ethanol-induced decrease in ERND activity. These results indicated that activation of Kupffer cells by gut-derived endotoxin contributes to downregulation of hepatic PXR and P450 3A11 expression during chronic alcohol intoxication

  2. Review of the chronic exposure pathways models in MACCS [MELCOR Accident Consequence Code System] and several other well-known probabilistic risk assessment models

    International Nuclear Information System (INIS)

    The purpose of this report is to document the results of the work performed by the author in connection with the following task, performed for US Nuclear Regulatory Commission, (USNRC) Office of Nuclear Regulatory Research, Division of Systems Research: MACCS Chronic Exposure Pathway Models: Review the chronic exposure pathway models implemented in the MELCOR Accident Consequence Code System (MACCS) and compare those models to the chronic exposure pathway models implemented in similar codes developed in countries that are members of the OECD. The chronic exposures concerned are via: the terrestrial food pathways, the water pathways, the long-term groundshine pathway, and the inhalation of resuspended radionuclides pathway. The USNRC has indicated during discussions of the task that the major effort should be spent on the terrestrial food pathways. There is one chapter for each of the categories of chronic exposure pathways listed above

  3. Chronic toxicity of uranium to a tropical green alga (Chlorella sp.) in natural waters and the influence of dissolved organic carbon

    International Nuclear Information System (INIS)

    The chronic toxicity (72-h cell division rate) of uranium (U) to the unicellular alga, Chlorella sp., was assessed in natural Magela Creek water (NMCW) to provide data for the derivation of a site-specific water quality trigger value for U in Magela Creek, NT, Australia. In addition, the data were compared to those for Chlorella sp. when tested for U toxicity using synthetic Magela Creek water (SMCW), which simulates the inorganic composition of Magela Creek water and contains no organic component. Based on one rangefinder and four definitive toxicity tests, concentrations causing a 50% inhibition of algal growth after 72 h exposure (72 h IC50s) ranged between 137 and 238 μg/L U, no-observed-effect concentrations (NOECs) from 72 to 157 μg/L U and lowest-observed-effect concentrations (LOECs) from 120 to 187 μg/L U. Based on these data, Chlorella sp. was the second most sensitive organism to U of five local species that have been assessed using NMCW. The U toxicity data for Chlorella sp. were incorporated with existing data for the four other species to derive a site-specific guideline value for Magela Creek that is protective of 99% of species of 6 μg/L. The toxicity of U to Chlorella sp. in NMCW was approximately two to four times lower than in SMCW. Based on geochemical speciation modelling, this difference corresponded to a four-fold decrease in the proportion of free uranyl ion (UO22+) in NMCW compared to SMCW, most likely due to the presence of dissolved organic carbon (DOC) in NMCW. Relatively, large variability in U toxicity across the tests conducted in NMCW was found to be inversely related to DOC concentration (r 2 = 0.996, n = 4, P = 0.002). Speciation modelling indicated that the increase in DOC was associated with an increase in the proportion of U complexed with DOC (r 2 = 0.986, n = 4, P 22+ (r 2 = 0.989, n = 4, P = 0.006). When the proportion of UO22+ was regressed against U toxicity, a very strong, positive relationship was observed (r 2 = 1, n

  4. Tissue-specific Bio-accumulation of Metals in Fish during Chronic Waterborne and Dietary Exposures

    Directory of Open Access Journals (Sweden)

    M. Javed

    2012-10-01

    Full Text Available Juvenile (120-day three fish species viz. Catla catla, Labeo rohita and Cirrhina mrigala were exposed to chronic sub-lethal concentrations (1/3rd of LC50/LD50 of waterborne and dietary copper (Cu, cadmium (Cd, zinc (Zn, nickel (Ni and cobalt (Co, separately, in glass aquaria under constant water temperature (29oC, pH (7.5 and hardness (225 mgL-1 for 12 weeks. Waterborne and dietary exposures caused significantly variable accumulation of metals in three fish species that followed Zn>Ni>Cd>Co>Cu. Fish liver showed significantly higher tendency to accumulate Cu (69.64±25.35 µg g-1, Cd (68.93±21.65 µg g-1, Zn (91.46±29.53 µg g-1, Ni (74.64±18.61 µg g-1 and Co (22.65±20.56 µg g-1, followed by that of kidney and gills, with significant differences while muscle and bones exhibited significantly least tendency to accumulate all metals. Labeo rohita (31.63±2.43 µg g-1 and C. mrigala (31.43±13.70 µg g-1 exhibited significantly higher ability to amass metals than that of C. catla (27.96±10.28 µg g-1. Waterborne exposure caused significantly higher accumulation of metals in fish liver (72.69±27.91 µg g-1, followed by that in kidney, gills, skin, muscle, fins and bones with the average concentrations of 45.14±18.70, 39.47±21.13, 30.81±12.64, 22.65±17.34, 22.23±11.74 and 12.14±6.25 µg g-1, respectively. Dietary exposure resulted into significant escalation of metals in fish liver (58.23±32.44 µg g-1 while it was lowest in bones. Waterborne exposure caused significantly higher accumulation of all metals in fish body than that of dietary treatments.

  5. Dust exposure and chronic respiratory symptoms among coffee curing workers in Kilimanjaro: a cross sectional study

    Directory of Open Access Journals (Sweden)

    Sakwari Gloria

    2011-11-01

    Full Text Available Abstract Background Coffee processing causes organic dust exposure which may lead to development of respiratory symptoms. Previous studies have mainly focused on workers involved in roasting coffee in importing countries. This study was carried out to determine total dust exposure and respiratory health of workers in Tanzanian primary coffee-processing factories. Methods A cross sectional study was conducted among 79 workers in two coffee factories, and among 73 control workers in a beverage factory. Personal samples of total dust (n = 45 from the coffee factories and n = 19 from the control factory were collected throughout the working shift from the breathing zone of the workers. A questionnaire with modified questions from the American Thoracic Society questionnaire was used to assess chronic respiratory symptoms. Differences between groups were tested by using independent t-tests and Chi square tests. Poisson Regression Model was used to estimate prevalence ratio, adjusting for age, smoking, presence of previous lung diseases and years worked in dusty factories. Results All participants were male. The coffee workers had a mean age of 40 years and were older than the controls (31 years. Personal total dust exposure in the coffee factories were significantly higher than in the control factory (geometric mean (GM 1.23 mg/m3, geometric standard deviation (GSD (0.8 vs. 0.21(2.4 mg/m3. Coffee workers had significantly higher prevalence than controls for cough with sputum (23% vs. 10%; Prevalence ratio (PR; 2.5, 95% CI 1.0 - 5.9 and chest tightness (27% vs. 13%; PR; 2.4, 95% CI 1.1 - 5.2. The prevalence of morning cough, cough with and without sputum for 4 days or more in a week was also higher among coffee workers than among controls. However, these differences were not statistically significant. Conclusion Workers exposed to coffee dust reported more respiratory symptoms than did the controls. This might relate to their exposure to coffee dust

  6. Biological effects and oxidative stress responses in Arabidopsis thaliana following exposure to uranium and copper

    Energy Technology Data Exchange (ETDEWEB)

    Horemans, N.; Saenen, E.; Vandenhove, H.; Vanhoudt, N.; Wannijn, J.; Nauts, R. [Belgian Nuclear Research Centre SCK-CEN (Belgium); Vangronsveld, J.; Cuypers, A. [Hasselt University (Belgium)

    2014-07-01

    Since organisms are almost always exposed to multiple stressors, it is important to investigate the toxicity effects in plants in a multiple stressor context to provide a more realistic estimate of environmental risks. Therefore, we evaluated the toxicity of U and Cu individually and in combination. Arabidopsis thaliana plants were exposed during 3 days to 25 μM U, 2.5 μM Cu or 12.5 μM U + 1.25 μM Cu at pH 7.5. The concentrations of U and Cu administered to the plants were the derived EC30 values for plant growth reduction based on the single-dose response curves. When plants were exposed to U or Cu, this resulted in an increased metal concentration in both roots and shoots as compared to the control plants. The increased Cu content of the plant, led to a significant decrease in leaf and root growth, while U exposure did not affect plant growth. By exposing plants to both metals, it seems that Cu interferes with the translocation of U from the roots to the leaves. In addition, U interferes with the Cu uptake, since less Cu was found in the roots than expected. This can probably be explained by the fact that U causes a shift in the Cu speciation in our medium. As such, the percentage of the bioavailable fractions of Cu decreased, while the percentage Cu-EDTA (i.e. non-available fraction) increased. No effects on plant growth were observed by exposing plants to U+Cu. Exposing plants to heavy metals can lead to an increased production of reactive oxygen species (ROS). After U or Cu exposure, the transcript levels of different ROS-producing enzymes (NADPH oxidases and lipoxygenases (LOX)) were up-regulated in the roots. Furthermore, exposing plants to U+Cu resulted in a 20-fold increase in the expression of LOX1 as compared to the single stressor conditions. This possibly indicates an enhanced ROS production. In addition, the increased expression of LOX1 can also indicate an increased production of oxylipins, important molecules in inter-organ signalling. In the

  7. Chronic cocaine or ethanol exposure during adolescence alters novelty-related behaviors in adulthood.

    Science.gov (United States)

    Stansfield, Kirstie H; Kirstein, Cheryl L

    2007-04-01

    Adolescence is a time of high-risk behavior and increased exploration. This developmental period is marked by a greater probability to initiate drug use and is associated with an increased risk to develop addiction and adulthood dependency and drug use at this time is associated with an increased risk. Human adolescents are predisposed toward an increased likelihood of risk-taking behaviors [Zuckerman M. Sensation seeking and the endogenous deficit theory of drug abuse. NIDA Res Monogr 1986;74:59-70.], including drug use or initiation. In the present study, adolescent animals were exposed to twenty days of either saline (0.9% sodium chloride), cocaine (20 mg/kg) or ethanol (1 g/kg) i.p. followed by a fifteen-day washout period. All animals were tested as adults on several behavioral measures including locomotor activity induced by a novel environment, time spent in the center of an open field, novelty preference and novel object exploration. Animals exposed to cocaine during adolescence and tested as adults exhibited a greater locomotor response in a novel environment, spent less time in the center of the novel open field and spent less time with a novel object, results that are indicative of a stress or anxiogenic response to novelty or a novel situation. Adolescent animals chronically administered ethanol and tested as adults, unlike cocaine-exposed were not different from controls in a novel environment, indicated by locomotor activity or time spent with a novel object. However, ethanol-exposed animals approached the novel object more, suggesting that exposure to ethanol during development may result in less-inhibited behaviors during adulthood. The differences in adult behavioral responses after drug exposure during adolescence are likely due to differences in the mechanisms of action of the drugs and subsequent reward and/or stress responsivity. Future studies are needed to determine the neural substrates of these long lasting drug-induced changes. PMID

  8. Rat lung macrophage tumor cytotoxin production: impairment by chronic in vivo cigarette smoke exposure.

    Science.gov (United States)

    Flick, D A; Gonzalez-Rothi, R J; Harris, J O; Gifford, G E

    1985-11-01

    Macrophages in the presence of bacteria-derived lipopolysaccharide (LPS) stimuli produce a soluble cytotoxin which is toxic to tumor cells. In this study, we examined various parameters of cytotoxin production from pulmonary lavage cells obtained from Fisher 344 cesarean-derived rats. Cultures of macrophages were derived from pulmonary lavage cells and stimulated in vitro with LPS. Cytotoxin production was assayed in vitro using an L-929 cell target assay. Pulmonary lavage preparations contained a relatively pure population of macrophages, and adherence studies revealed that nonadherent lavage cells contributed negligible amounts of cytotoxin, indicating that macrophages were responsible for cytotoxin production. After LPS stimulation, cytotoxin production became maximal within 10 h and thereafter plateaued. Doses of LPS above 0.1 microgram/ml were optimal for production, and in the absence of LPS, no cytotoxin was detected. Because cigarette smoke is the major etiological factor in the development of lung cancers and because smoking is known to profoundly alter the function of alveolar macrophages in humans and experimental animals, subsequent experiments examined the role of chronic cigarette smoke exposure on tumoricidal activity of lung macrophages. Rats were exposed in vivo for 8 wk to either cigarette smoke or air (sham-treated controls). When lavage cells were cultured and stimulated with LPS (1 microgram/ml), 5- to 10-fold less cytotoxin was produced by lavage cells from rats exposed to cigarette smoke. Similarly, using a direct cytotoxicity assay, lung macrophages of smoke-exposed animals also revealed marked impairment in cytotoxicity against L-929 cell targets, and this was noted over a wide range of macrophage:tumor target cell ratios. Another product of macrophages, interferon, was also decreased in rats exposed in vivo to cigarette smoke when compared to sham-treated controls. These results suggest that cigarette smoke exposure may impair pulmonary

  9. Effects of acute or chronic ethanol exposure during adolescence on behavioral inhibition and efficiency in a modified water maze task.

    Directory of Open Access Journals (Sweden)

    Shawn K Acheson

    Full Text Available Ethanol is well known to adversely affect frontal executive functioning, which continues to develop throughout adolescence and into young adulthood. This is also a developmental window in which ethanol is misused by a significant number of adolescents. We examined the effects of acute and chronic ethanol exposure during adolescence on behavioral inhibition and efficiency using a modified water maze task. During acquisition, rats were trained to find a stable visible platform onto which they could escape. During the test phase, the stable platform was converted to a visible floating platform (providing no escape and a new hidden platform was added in the opposite quadrant. The hidden platform was the only means of escape during the test phase. In experiment 1, adolescent animals received ethanol (1.0 g/kg 30 min before each session during the test phase. In experiment 2, adolescent animals received chronic intermittent ethanol (5.0 g/kg for 16 days (PND30 To PND46 prior to any training in the maze. At PND72, training was initiated in the same modified water maze task. Results from experiment 1 indicated that acute ethanol promoted behavioral disinhibition and inefficiency. Experiment 2 showed that chronic intermittent ethanol during adolescence appeared to have no lasting effect on behavioral disinhibition or new spatial learning during adulthood. However, chronic ethanol did promote behavioral inefficiency. In summary, results indicate that ethanol-induced promotion of perseverative behavior may contribute to the many adverse behavioral sequelae of alcohol intoxication in adolescents and young adults. Moreover, the long-term effect of adolescent chronic ethanol exposure on behavioral efficiency is similar to that observed after chronic exposure in humans.

  10. Effects of Acute and Chronic Heavy Metal (Cu, Cd, and Zn Exposure on Sea Cucumbers (Apostichopus japonicus

    Directory of Open Access Journals (Sweden)

    Li Li

    2016-01-01

    Full Text Available Acute and chronic toxicity tests were conducted with sea cucumber (Apostichopus japonicus exposed to heavy metals. Acute toxicity values (96 h LC50 were 2.697, 0.133, and 1.574 mg L−1 for Zn, Cu, and Cd, respectively, and were ranked in order of toxicity: Cu > Cd > Zn. Under chronic metal exposure the specific growth rates of sea cucumbers decreased with the increase of metal concentration for all the three metals. After acute metal exposure, the oxygen consumption rate (OCR decreased. The OCRs in all groups were significantly different than control (P muscle > intestine in natural sea water. After chronic Zn, Cu, and Cd exposure, the change pattern of HK and PK in respiratory tree, muscle, and intestine varied slightly. However, the activity of the enzyme showed a general trend of increase and then decrease and the higher the exposure concentration was, the earlier the highest point of enzyme activity was obtained.

  11. The chronic toxicity of bisphenol A to Caenorhabditis elegans after long-term exposure at environmentally relevant concentrations.

    Science.gov (United States)

    Zhou, Dong; Yang, Jie; Li, Hui; Cui, Changzheng; Yu, Yunjiang; Liu, Yongdi; Lin, Kuangfei

    2016-07-01

    To investigate biological effects of bisphenol A (BPA) over the long term, the model animal Caenorhabditis elegans was used to conduct the chronic exposure. C. elegans were exposed to BPA (0.0001-10 μM) from L4 larvae to day-10 adult in the present chronic toxicity assay system. Multiple endpoints at the physiological (growth, locomotion behaviors and lifespan), biochemical (lipofuscin accumulation), molecular (stress-related genes expressions), and population (population size) levels were examined. At the physiological level, BPA exposure induced significant negative effects on the indicators. Among the endpoints, head thrash was most sensitive and the detection limit was 0.001 μM. At the biochemical level, BPA exposure induced no significant effects on lipofuscin accumulation. At the molecular level, BPA induced strong stress responses in vivo. At the population level, the population size was significantly decreased in the treatment groups from 0.1 to 10 μM. Compared to the previous short-term toxicity evaluation, long-term exposure to BPA induced a more obvious response at the same concentration, and the phenomenon might be due to cumulative toxic effects. By the Pearson correlation analyses, cep-1 was speculated to act as an important role in BPA-induced chronic toxicity on C. elegans. PMID:27085314

  12. Ways of pharmacological prophylaxis of stochastic and deterministic effects of chronical radiation exposure

    International Nuclear Information System (INIS)

    The prophylactics of late effects of exposure is the actual medico-social problem, because now there are large groups of persons who were exposed during occupational contact and living on territories contaminated by radionuclides. Most probable consequences of external and internal chronic influence of radiation may be the increase of malignant tumour frequency, the development of secondary myelo- and immuno-depressions, the earlier forming of sclerous and destructive processes, and the acceleration of senescence. The role of damages in immune system was not yet understood in pathogenesis of the late effects of radiation, but there are evidences that the decreasing of the immunologic supervision in period of forming the consequences of radiation influence enables to realize the cancerogenic effect of radiation. The purposes of this investigation are to decrease the frequency or to prevent the development of radiation consequences dangerous for health and life by using the method of modification of radiogenic damages in hemopoietic and immune systems by applying the pharmacological preparations with immunomodulating effects. The investigation tasks include: the study of modifying influence of pharmacological substances with different mechanisms of effect: myelopid (immunomodulating, and regulatory), β-carotin, Calendula officinalis (immunomodulating, and antioxidant), lipamid (detoxicating); the separate or complex applications of these substances; and the development of the optimum medico-prophylactic schemes. The advantages of these indicated preparations in comparison with the known (T-activin, thymogen, cytokines, etc.) are the absence of contraindications and the possibility to use per os. (author)

  13. Metamorphosis of two amphibian species after chronic cadmium exposure in outdoor aquatic mesocosms

    Science.gov (United States)

    James, S.M.; Little, E.E.; Semlitsch, R.D.

    2005-01-01

    Amphibian larvae at contaminated sites may experience an alteration of metamorphic traits and survival compared to amphibians in uncontaminated conditions. Effects of chronic cadmium (Cd) exposure on the metamorphosis of American toads (Bufo americanus) and southern leopard frogs (Rana sphenocephala) were determined. The two species were reared separately from shortly after hatching through metamorphosis in outdoor mesocosms (1,325-L polyethylene cattle tanks) that simulated natural ponds and enhanced environmental realism relative to the laboratory. Both species exhibited a decrease in survival with increasing initial nominal aqueous Cd concentration. Cadmium treatment did not influence mass at metamorphosis for either species when survival was included as a covariate, but increased the age at metamorphosis for the American toads. The whole body Cd content of metamorphs increased with aqueous Cd treatment level for both species, and the American toads tended to possess more elevated residues. Cadmium quickly partitioned out of the water column and accumulated in and altered the abundance of the tadpoles' diet. Cadmium-contaminated sites may produce fewer metamorphs, and those that survive will metamorphose later and contain Cd. Interspecific differences in the response variables illustrate the importance of testing multiple species when assessing risk. ?? 2005 SETAC.

  14. Modelling the propagation of effects of chronic exposure to ionising radiation from individuals to populations

    Energy Technology Data Exchange (ETDEWEB)

    Alonzo, F. [Laboratory of Environmental Modelling, DEI/SECRE/LME, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache, Building 159, BP3, 13115 St-Paul-lez-Durance Cedex (France); Laboratory of Radioecology and Ecotoxicology, DEI/SECRE/LRE, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France)], E-mail: frederic.alonzo@irsn.fr; Hertel-Aas, T. [Department of Plant and Environmental Sciences, P.O. Box 5003, Norwegian University of Life Sciences, 1432 Aas (Norway); Gilek, M. [School of Life Sciences, Soedertoern University College, 14189 Huddinge (Sweden); Gilbin, R. [Laboratory of Radioecology and Ecotoxicology, DEI/SECRE/LRE, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France); Oughton, D.H. [Department of Plant and Environmental Sciences, P.O. Box 5003, Norwegian University of Life Sciences, 1432 Aas (Norway); Garnier-Laplace, J. [Laboratory of Radioecology and Ecotoxicology, DEI/SECRE/LRE, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France)

    2008-09-15

    This study evaluated the potential effect of ionising radiation on population growth using simple population models and parameter values derived from chronic exposure experiments in two invertebrate species with contrasting life-history strategies. In the earthworm Eisenia fetida, models predicted increasing delay in population growth with increasing gamma dose rate (up to 0.6 generation times at 11 mGy h{sup -1}). Population extinction was predicted at 43 mGy h{sup -1}. In the microcrustacean Daphnia magna, models predicted increasing delay in population growth with increasing alpha dose rate (up to 0.8 generation times at 15.0 mGy h{sup -1}), only after two successive generations were exposed. The study examined population effects of changes in different individual endpoints (including survival, number of offspring produced and time to first reproduction). Models showed that the two species did not respond equally to equivalent levels of change, the fast growing daphnids being more susceptible to reduction in fecundity or delay in reproduction than the slow growing earthworms. This suggested that susceptibility of a population to ionising radiation cannot be considered independent of the species' life history.

  15. HIGH-Resolution CT in Chronic Pulmonary Changes after Mustard Gas Exposure

    Energy Technology Data Exchange (ETDEWEB)

    Bagheri, M.H.; Mostafavi, S.H. [Shiraz Univ. of Medical Siences (Iran, Islamic Republic of). Dept. of Radiology; Hosseini, S.K. [Shiraz Univ. of Medical Siences (Iran, Islamic Republic of). Dept. of Internal Medicine; Alavi, S.A. [Medical Center for Chemical Warfare Victims Foundation, Shiraz (Iran, Islamic Republic of)

    2003-05-01

    Purpose: To identify the findings of high-resolution CT (HRCT) of the lung in patients with previous sulfur mustard gas exposure, and to correlate these findings with clinical and chest X-ray (CXR) results. Material and Methods: 50 consecutive patients were studied prospectively. The clinical data were recorded. Standard p.a. CXR and HRCT of the lung and spirometry were performed. The findings of CXR, HRCT and clinical and spirometry results were scored between 0 and 3 according to the severity of the findings. Results: HRCT abnormality was detected in all 50 patients (100%), while CXR was abnormal in 40 patients (80%). The most common HRCT findings was airway abnormalities (bronchial wall thickening in 100% of cases). Other important findings were suggestive of interstitial lung disease (ILD) (80%), bronchiectasis (26%), and emphysema (24%). A statistically significant correlation was found between the severity of clinical presentation and that of the HCTR scores in patients with bronchiectasis, bronchitis and ILD (p< 0.05), but not with severity scores of HRCT in patients with emphysema. No significant correlation was found between severity scores of CXR findings. HRCT evidence of bronchial wall thickening and with a lower frequency ILD were present despite normal CXR in 20% of the patients. Conclusion: The results of this study suggest that bronchial wall thickening, ILD and emphysema are common chronic pulmonary sequelae of sulfur mustard injury. HRCT of the chest should be considered as the imaging modality of choice in chemical war injury.

  16. HIGH-Resolution CT in Chronic Pulmonary Changes after Mustard Gas Exposure

    International Nuclear Information System (INIS)

    Purpose: To identify the findings of high-resolution CT (HRCT) of the lung in patients with previous sulfur mustard gas exposure, and to correlate these findings with clinical and chest X-ray (CXR) results. Material and Methods: 50 consecutive patients were studied prospectively. The clinical data were recorded. Standard p.a. CXR and HRCT of the lung and spirometry were performed. The findings of CXR, HRCT and clinical and spirometry results were scored between 0 and 3 according to the severity of the findings. Results: HRCT abnormality was detected in all 50 patients (100%), while CXR was abnormal in 40 patients (80%). The most common HRCT findings was airway abnormalities (bronchial wall thickening in 100% of cases). Other important findings were suggestive of interstitial lung disease (ILD) (80%), bronchiectasis (26%), and emphysema (24%). A statistically significant correlation was found between the severity of clinical presentation and that of the HCTR scores in patients with bronchiectasis, bronchitis and ILD (p< 0.05), but not with severity scores of HRCT in patients with emphysema. No significant correlation was found between severity scores of CXR findings. HRCT evidence of bronchial wall thickening and with a lower frequency ILD were present despite normal CXR in 20% of the patients. Conclusion: The results of this study suggest that bronchial wall thickening, ILD and emphysema are common chronic pulmonary sequelae of sulfur mustard injury. HRCT of the chest should be considered as the imaging modality of choice in chemical war injury

  17. Acute and chronic ethanol exposure differentially regulate CB1 receptor function at glutamatergic synapses in the rat basolateral amygdala.

    Science.gov (United States)

    Robinson, Stacey L; Alexander, Nancy J; Bluett, Rebecca J; Patel, Sachin; McCool, Brian A

    2016-09-01

    The endogenous cannabinoid (eCB) system has been suggested to play a key role in ethanol preference and intake, the acute effects of ethanol, and in the development of withdrawal symptoms following ethanol dependence. Ethanol-dependent alterations in glutamatergic signaling within the lateral/basolateral nucleus of the amygdala (BLA) are critical for the development and expression of withdrawal-induced anxiety. Notably, the eCB system significantly regulates both glutamatergic and GABAergic synaptic activity within the BLA. Chronic ethanol exposure significantly alters eCB system expression within regions critical to the expression of emotionality and anxiety-related behavior, including the BLA. Here, we investigated specific interactions between the BLA eCB system and its functional regulation of synaptic activity during acute and chronic ethanol exposure. In tissue from ethanol naïve-rats, a prolonged acute ethanol exposure caused a dose dependent inhibition of glutamatergic synaptic activity via a presynaptic mechanism that was occluded by CB1 antagonist/inverse agonists SR141716a and AM251. Importantly, this acute ethanol inhibition was attenuated following 10 day chronic intermittent ethanol vapor exposure (CIE). CIE exposure also significantly down-regulated CB1-mediated presynaptic inhibition at glutamatergic afferent terminals but spared CB1-inhibition of GABAergic synapses arising from local inhibitory-interneurons. CIE also significantly elevated BLA N-arachidonoylethanolamine (AEA or anandamide) levels and decreased CB1 receptor protein levels. Collectively, these data suggest a dynamic regulation of the BLA eCB system by acute and chronic ethanol. PMID:26707595

  18. Effects of an acute and a sub-chronic 900 MHz GSM exposure on brain activity and behaviors of rats

    Energy Technology Data Exchange (ETDEWEB)

    Elsa Brillaud; Aleksandra Piotrowski; Anthony Lecomte; Franck Robidel; Rene de Seze [Toxicology Unit, INERIS, Verneuil en Halatte (France)

    2006-07-01

    Radio frequencies are suspected to produce health effects. Concerning the mobile phone technology, according to position during use (close to the head), possible effects of radio frequencies on the central nervous system have to be evaluated. Previous works showed contradictory results, possibly due to experimental design diversity. In the framework of R.A.M.P. 2001 project, we evaluated possible effect of a 900 MHz GSM exposure on the central nervous system of rat at a structural, a functional and a behavioral level after acute or sub-chronic exposures. Rats were exposed using a loop antenna system to different S.A.R. levels and durations, according to results of the French C.O.M.O.B.I.O. 2001 project. A functional effect was found (modification of the cerebral activity and increase of the glia surface) after an acute exposure, even at a low level of brain averaged S.A.R. (1.5 W/kg). No cumulative effect was observed after a sub-chronic exposure (same amplitude of the effect). No structural or behavioral consequence was noted. We do not conclude on the neurotoxicity of the 900 MHz GSM exposure on the rat brain. Our results do not indicate any health risk. (authors)

  19. Effects of an acute and a sub-chronic 900 MHz GSM exposure on brain activity and behaviors of rats

    International Nuclear Information System (INIS)

    Radio frequencies are suspected to produce health effects. Concerning the mobile phone technology, according to position during use (close to the head), possible effects of radio frequencies on the central nervous system have to be evaluated. Previous works showed contradictory results, possibly due to experimental design diversity. In the framework of R.A.M.P. 2001 project, we evaluated possible effect of a 900 MHz GSM exposure on the central nervous system of rat at a structural, a functional and a behavioral level after acute or sub-chronic exposures. Rats were exposed using a loop antenna system to different S.A.R. levels and durations, according to results of the French C.O.M.O.B.I.O. 2001 project. A functional effect was found (modification of the cerebral activity and increase of the glia surface) after an acute exposure, even at a low level of brain averaged S.A.R. (1.5 W/kg). No cumulative effect was observed after a sub-chronic exposure (same amplitude of the effect). No structural or behavioral consequence was noted. We do not conclude on the neurotoxicity of the 900 MHz GSM exposure on the rat brain. Our results do not indicate any health risk. (authors)

  20. Chronic hydrocarbon exposure of harlequin ducks in areas affected by the Selendang Ayu oil spill at Unalaska Island, Alaska

    Science.gov (United States)

    Flint, Paul L.; Schamber, J.L.; Trust, K.A.; Miles, A.K.; Henderson, J.D.; Wilson, B.W.

    2012-01-01

    We evaluated chronic exposure of harlequin ducks (Histrionicus histrionicus) to hydrocarbons associated with the 2004 M/V Selendang Ayu oil spill at Unalaska Island, Alaska. We measured levels of hepatic 7-ethoxyresorufin-O-deethylase activity (EROD) in liver biopsy samples as an indicator of hydrocarbon exposure in three oiled bays and one reference bay in 2005, 2006, and 2008. Median EROD activity in ducks from oiled bays was significantly higher than in the reference bay in seven of nine pairwise comparisons. These results indicated that harlequin ducks were exposed to lingering hydrocarbons more than three years after the spill.

  1. Plants experiencing chronic internal exposure to ionizing radiation exhibit higher frequency of homologous recombination than acutely irradiated plants

    Energy Technology Data Exchange (ETDEWEB)

    Kovalchuk, O.; Kovalchuk, I.; Hohn, B. [Friedrich Miescher Institute, P.O. Box 2543, CH-4002 Basel (Switzerland); Arkhipov, A. [Chernobyl Scientific and Technical Center of International Research, Shkolnaya Str. 6, 255620 Chernobyl (Ukraine); Barylyak, I.; Karachov, I. [Ukrainian Scientific Genetics Center, Popudrenko Str. 50, 253660 Kiev (Ukraine); Titov, V. [Ivano-Frankivsk State Medical Academy, Galitska Str.2, 284000 Ivano-Frankivsk (Ukraine)

    2000-04-03

    Ionizing radiation (IR) is a known mutagen responsible for causing DNA strand breaks in all living organisms. Strand breaks thus created can be repaired by different mechanisms, including homologous recombination (HR), one of the key mechanisms maintaining genome stability [A. Britt, DNA damage and repair in plants, Annu. Rev. Plant. Phys. Plant Mol. Biol., 45 (1996) 75-100; H. Puchta, B. Hohn, From centiMorgans to basepairs: homologous recombination in plants, Trends Plant Sci., 1 (1996) 340-348.]. Acute or chronic exposure to IR may have different influences on the genome integrity. Although in a radioactively contaminated environment plants are mostly exposed to chronic pollution, evaluation of both kinds of influences is important. Estimation of the frequency of HR in the exposed plants may serve as an indication of genome stability. We used previously generated Arabidopsis thaliana and Nicotiana tabacum plants, transgenic for non-active versions of the {beta}-glucoronidase gene (uidA) [P. Swoboda, S. Gal, B. Hohn, H. Puchta, Intrachromosomal homologous recombination in whole plants, EMBO J., 13 (1994) 484-489; H. Puchta, P. Swoboda, B. Hohn, Induction of homologous DNA recombination in whole plants, Plant, 7 (1995) 203-210.] serving as a recombination substrate, to study the influence of acute and chronic exposure to IR on the level of HR as example of genome stability in plants. Exposure of seeds and seedlings to 0.1 to 10.0 Gy 60Co resulted in increased HR frequency, although the effect was more pronounced in seedlings. For the study of the influence of chronic exposure to IR, plants were grown on two chemically different types of soils, each artificially contaminated with equal amounts of 137Cs. We observed a strong and significant correlation between the frequency of HR in plants, the radioactivity of the soil samples and the doses of radiation absorbed by plants (in all cases r0.9, n=6, P<0.05). In addition, we noted that plants grown in soils with

  2. Plants experiencing chronic internal exposure to ionizing radiation exhibit higher frequency of homologous recombination than acutely irradiated plants

    International Nuclear Information System (INIS)

    Ionizing radiation (IR) is a known mutagen responsible for causing DNA strand breaks in all living organisms. Strand breaks thus created can be repaired by different mechanisms, including homologous recombination (HR), one of the key mechanisms maintaining genome stability [A. Britt, DNA damage and repair in plants, Annu. Rev. Plant. Phys. Plant Mol. Biol., 45 (1996) 75-100; H. Puchta, B. Hohn, From centiMorgans to basepairs: homologous recombination in plants, Trends Plant Sci., 1 (1996) 340-348.]. Acute or chronic exposure to IR may have different influences on the genome integrity. Although in a radioactively contaminated environment plants are mostly exposed to chronic pollution, evaluation of both kinds of influences is important. Estimation of the frequency of HR in the exposed plants may serve as an indication of genome stability. We used previously generated Arabidopsis thaliana and Nicotiana tabacum plants, transgenic for non-active versions of the β-glucoronidase gene (uidA) [P. Swoboda, S. Gal, B. Hohn, H. Puchta, Intrachromosomal homologous recombination in whole plants, EMBO J., 13 (1994) 484-489; H. Puchta, P. Swoboda, B. Hohn, Induction of homologous DNA recombination in whole plants, Plant, 7 (1995) 203-210.] serving as a recombination substrate, to study the influence of acute and chronic exposure to IR on the level of HR as example of genome stability in plants. Exposure of seeds and seedlings to 0.1 to 10.0 Gy 60Co resulted in increased HR frequency, although the effect was more pronounced in seedlings. For the study of the influence of chronic exposure to IR, plants were grown on two chemically different types of soils, each artificially contaminated with equal amounts of 137Cs. We observed a strong and significant correlation between the frequency of HR in plants, the radioactivity of the soil samples and the doses of radiation absorbed by plants (in all cases r0.9, n=6, P<0.05). In addition, we noted that plants grown in soils with different

  3. PROVANN: Model System for Chronic Exposure of Larval and Adult Fish to Releases from Offshore Petroleum Platforms

    International Nuclear Information System (INIS)

    Produced water from offshore oil and gas production platforms contains a variety of hydrocarbons, heavy metals, and production chemicals. Vertical and horizontal mixing generally brings concentrations in discharge plumes below level associated with acute effects within 500 or 1000 m of the source. Chronic effects outside this region remain a potential problem. The purpose of PROVANN, the system of models described in this paper, is to assess the potential for chronic effects from produced water. The preliminary focus is on potential bioaccumulation and boimagnification of produced water constituents in the marine food web. Other possible types of chronic effects, such as reduced fecundity, or pheromone response interference, can also be assessed to the extent that such effects may be correlated with exposure. PROVANN simulates 3-dimensional transport, dilution, and degradation of chemicals released into the water, from one or more simultaneous sources. 8 refs., 10 figs., 3 tabs

  4. Chronic Exposure to Zinc Chromate Induces Centrosome Amplification and Spindle Assembly Checkpoint Bypass in Human Lung Fibroblasts

    OpenAIRE

    Holmes, Amie L.; Wise, Sandra S.; Pelsue, Stephen C.; Aboueissa, AbouEl-Makarim; Lingle, Wilma; Salisbury, Jeffery; Gallagher, Jamie; Wise, John Pierce

    2010-01-01

    Hexavalent chromium (Cr(VI)) compounds are known human lung carcinogens. Solubility plays an important role in its carcinogenicity with the particulate or insoluble form being the most potent. Of the particulate Cr(VI) compounds, zinc chromate appears to be the most potent carcinogen, however, very few studies have investigated its carcinogenic mechanism. In this study, we investigated the ability of chronic exposure to zinc chromate to induce numerical chromosome instability. We found no inc...

  5. Chronic exposure to low doses of pharmaceuticals disturbs the hepatic expression of circadian genes in lean and obese mice.

    OpenAIRE

    Anthérieu, Sébastien; Le Guillou, Dounia; Coulouarn, Cédric; Begriche, Karima; Trak-Smayra, Viviane; Martinais, Sophie; Porceddu, Mathieu; Robin, Marie-Anne; Fromenty, Bernard

    2014-01-01

    International audience Drinking water can be contaminated with pharmaceuticals. However, it is uncertain whether this contamination can be harmful for the liver, especially during obesity. Hence, the goal of our study was to determine whether chronic exposure to low doses of pharmaceuticals could have deleterious effects on livers of lean and obese mice. To this end, lean and ob/ob male mice were treated for 4 months with a mixture of 11 drugs provided in drinking water at concentrations r...

  6. Use of Polar Organic Chemical Integrative Samplers to assess the effects of chronic pesticide exposure on biofilms

    OpenAIRE

    Morin, S.; Pesce, S.; Kim Tiam, S.; Libert, X.; Coquery, M.; Mazzella, N.

    2012-01-01

    The responses of aquatic organisms to chronic exposure to environmental concentrations of toxicants, often found in mixtures, are poorly documented. Here passive sampler extracts were used in experimental contamination of laboratory channels, to investigate their effects on natural biofilm communities. A realistic mixture of pesticides extracted from POCIS (Polar Organic Chemical Integrative Samplers) was used to expose biofilms in laboratory channels to total pesticide concentrations averagi...

  7. CD44v6 expression in human skin keratinocytes as a possible mechanism for carcinogenesis associated with chronic arsenic exposure

    OpenAIRE

    Huang, S.; Guo, S.; Guo, F; Yang, Q.; XIAO, X.; Murata, M.; Ohnishi, S.; Kawanishi, S; Ma, N

    2013-01-01

    Inorganic arsenic is a well-known human skin carcinogen. Chronic arsenic exposure results in various types of human skin lesions, including squamous cell carcinoma (SCC). To investigate whether mutant stem cells participate in arsenic-associated carcinogenesis, we repeatedly exposed the human spontaneously immortalized skin keratinocytes (HaCaT) cell line to an environmentally relevant level of arsenic (0.05 ppm) in vitrofor 18 weeks. Following sodium arsenite administration, cell cycle, colo...

  8. Neutralisation of interleukin-13 in mice prevents airway pathology caused by chronic exposure to house dust mite.

    Directory of Open Access Journals (Sweden)

    Kate L Tomlinson

    Full Text Available BACKGROUND: Repeated exposure to inhaled allergen can cause airway inflammation, remodeling and dysfunction that manifests as the symptoms of allergic asthma. We have investigated the role of the cytokine interleukin-13 (IL-13 in the generation and persistence of airway cellular inflammation, bronchial remodeling and deterioration in airway function in a model of allergic asthma caused by chronic exposure to the aeroallergen House Dust Mite (HDM. METHODOLOGY/PRINCIPAL FINDINGS: Mice were exposed to HDM via the intranasal route for 4 consecutive days per week for up to 8 consecutive weeks. Mice were treated either prophylactically or therapeutically with a potent neutralising anti-IL-13 monoclonal antibody (mAb administered subcutaneously (s.c.. Airway cellular inflammation was assessed by flow cytometry, peribronchial collagen deposition by histocytochemistry and airway hyperreactivity (AHR by invasive measurement of lung resistance (R(L and dynamic compliance (C(dyn. Both prophylactic and therapeutic treatment with an anti-IL-13 mAb significantly inhibited (P<0.05 the generation and maintenance of chronic HDM-induced airway cellular inflammation, peribronchial collagen deposition, epithelial goblet cell upregulation. AHR to inhaled methacholine was reversed by prophylactic but not therapeutic treatment with anti-IL-13 mAb. Both prophylactic and therapeutic treatment with anti-IL-13 mAb significantly reversed (P<0.05 the increase in baseline R(L and the decrease in baseline C(dyn caused by chronic exposure to inhaled HDM. CONCLUSIONS/SIGNIFICANCE: These data demonstrate that in a model of allergic lung disease driven by chronic exposure to a clinically relevant aeroallergen, IL-13 plays a significant role in the generation and persistence of airway inflammation, remodeling and dysfunction.

  9. Chronic inorganic arsenic exposure in vitro induces a cancer cell phenotype in human peripheral lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Person, Rachel J.; Olive Ngalame, Ntube N.; Makia, Ngome L.; Bell, Matthew W.; Waalkes, Michael P.; Tokar, Erik J., E-mail: tokare@niehs.nih.gov

    2015-07-01

    Inorganic arsenic is a human lung carcinogen. We studied the ability of chronic inorganic arsenic (2 μM; as sodium arsenite) exposure to induce a cancer phenotype in the immortalized, non-tumorigenic human lung peripheral epithelial cell line, HPL-1D. After 38 weeks of continuous arsenic exposure, secreted matrix metalloproteinase-2 (MMP2) activity increased to over 200% of control, levels linked to arsenic-induced cancer phenotypes in other cell lines. The invasive capacity of these chronic arsenic-treated lung epithelial (CATLE) cells increased to 320% of control and colony formation increased to 280% of control. CATLE cells showed enhanced proliferation in serum-free media indicative of autonomous growth. Compared to control cells, CATLE cells showed reduced protein expression of the tumor suppressor gene PTEN (decreased to 26% of control) and the putative tumor suppressor gene SLC38A3 (14% of control). Morphological evidence of epithelial-to-mesenchymal transition (EMT) occurred in CATLE cells together with appropriate changes in expression of the EMT markers vimentin (VIM; increased to 300% of control) and e-cadherin (CDH1; decreased to 16% of control). EMT is common in carcinogenic transformation of epithelial cells. CATLE cells showed increased KRAS (291%), ERK1/2 (274%), phosphorylated ERK (p-ERK; 152%), and phosphorylated AKT1 (p-AKT1; 170%) protein expression. Increased transcript expression of metallothioneins, MT1A and MT2A and the stress response genes HMOX1 (690%) and HIF1A (247%) occurred in CATLE cells possibly in adaptation to chronic arsenic exposure. Thus, arsenic induced multiple cancer cell characteristics in human peripheral lung epithelial cells. This model may be useful to assess mechanisms of arsenic-induced lung cancer. - Highlights: • Chronic arsenic exposure transforms a human peripheral lung epithelia cell line. • Cells acquire characteristics in common with human lung adenocarcinoma cells. • These transformed cells provide a

  10. Effects of Chronic and Acute Ozone Exposure on Lipid Peroxidation and Antioxidant Capacity in Healthy Young Adults

    OpenAIRE

    Chen, Connie; Arjomandi, Mehrdad; Balmes, John; Tager, Ira; Holland, Nina

    2007-01-01

    Background There is growing evidence for the role of oxidative damage in chronic diseases. Although ozone (O3) is an oxidant pollutant to which many people are exposed, few studies have examined whether O3 induces oxidative stress in humans. Objectives This study was designed to assess the effect of short-and long-term O3 exposures on biomarkers of oxidative stress in healthy individuals. Methods Biomarkers of lipid peroxidation, 8-isoprostane (8-iso-PGF), and antioxidant capacity ferric redu...

  11. Chronic inorganic arsenic exposure in vitro induces a cancer cell phenotype in human peripheral lung epithelial cells

    International Nuclear Information System (INIS)

    Inorganic arsenic is a human lung carcinogen. We studied the ability of chronic inorganic arsenic (2 μM; as sodium arsenite) exposure to induce a cancer phenotype in the immortalized, non-tumorigenic human lung peripheral epithelial cell line, HPL-1D. After 38 weeks of continuous arsenic exposure, secreted matrix metalloproteinase-2 (MMP2) activity increased to over 200% of control, levels linked to arsenic-induced cancer phenotypes in other cell lines. The invasive capacity of these chronic arsenic-treated lung epithelial (CATLE) cells increased to 320% of control and colony formation increased to 280% of control. CATLE cells showed enhanced proliferation in serum-free media indicative of autonomous growth. Compared to control cells, CATLE cells showed reduced protein expression of the tumor suppressor gene PTEN (decreased to 26% of control) and the putative tumor suppressor gene SLC38A3 (14% of control). Morphological evidence of epithelial-to-mesenchymal transition (EMT) occurred in CATLE cells together with appropriate changes in expression of the EMT markers vimentin (VIM; increased to 300% of control) and e-cadherin (CDH1; decreased to 16% of control). EMT is common in carcinogenic transformation of epithelial cells. CATLE cells showed increased KRAS (291%), ERK1/2 (274%), phosphorylated ERK (p-ERK; 152%), and phosphorylated AKT1 (p-AKT1; 170%) protein expression. Increased transcript expression of metallothioneins, MT1A and MT2A and the stress response genes HMOX1 (690%) and HIF1A (247%) occurred in CATLE cells possibly in adaptation to chronic arsenic exposure. Thus, arsenic induced multiple cancer cell characteristics in human peripheral lung epithelial cells. This model may be useful to assess mechanisms of arsenic-induced lung cancer. - Highlights: • Chronic arsenic exposure transforms a human peripheral lung epithelia cell line. • Cells acquire characteristics in common with human lung adenocarcinoma cells. • These transformed cells provide a

  12. Chronic CO2 exposure markedly increases the incidence of cataracts in juvenile Atlantic cod Gadus morhua L

    DEFF Research Database (Denmark)

    Moran, Damian; Tubbs, Lincoln; Støttrup, Josianne G.

    2012-01-01

    A study was undertaken to test the affect of chronic exposure to elevated dissolved carbon dioxide on juvenile Atlantic cod. The CO2 treatment concentrations were designated as low (1–2mgL−1, 1000μatm), medium (8mgL−1, 3500μatm) and high (18mgL−1, 8500μatm), and the fish were reared at 10°C and 2...

  13. Association between Blood Dioxin Level and Chronic Kidney Disease in an Endemic Area of Exposure.

    Directory of Open Access Journals (Sweden)

    Chien-Yuan Huang

    Full Text Available Dioxin is an industrial pollutant related to various diseases, but epidemiological data on its effects on the kidney are limited. Therefore, we conducted a study to evaluate the association between dioxin exposure and chronic kidney disease (CKD and identify the related factors.We conducted a community-based cross-sectional study and recruited participants from an area where the residents were exposed to dioxin released from a factory. We defined a "high dioxin level" as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs ≥ 20 pg WHO98-TEQDF/g lipid in the serum and defined CKD as having an estimated glomerular filtration rate (e-GFR ≤ 60 mL/min/1.73m2 or a diagnosis of CKD by a physician. The renal function was assessed between 2005 and 2010, and we excluded those who had had kidney diseases before the study started. Comparisons between patients of CKD and those who did not have CKD were made to identify the risk factors for CKD.Of the 2898 participants, 1427 had high dioxin levels, and 156 had CKD. In the univariate analyses, CKD was associated with high dioxin levels, age, gender, metabolic syndrome, diabetes mellitus, hypertension, and high insulin and uric acid levels. After adjusting for other factors, we found high dioxin levels (adjusted odds ratio [AOR] = 1.76, 95% confidence interval [CI]: 1.04-2.99, female gender (AOR = 1.74, 95%CI: 1.20-2.53, hypertension (AOR = 1.68, 95%CI: 1.17-2.42, high insulin levels (AOR = 2.14, 95% CI: 1.26-3.61, high uric acid levels (AOR = 4.25, 95% CI: 2.92-6.20, and older age (AOR = 4.66, 95% CI: 1.87-11.62 for 40-64 year and AOR = 26.66, 95% CI: 10.51-67.62 for age ≥ 65 year were independent predictors of CKD.A high dioxin level was associated with an increased prevalence of CKD. Therefore, the kidney function of populations with exposure to dioxin should be monitored.

  14. Yohimbine reinstates extinguished 3,4-methylenedioxymethamphetamine (MDMA; ecstasy) seeking in rats with prior exposure to chronic yohimbine.

    Science.gov (United States)

    Ball, Kevin T; Jarsocrak, Hanna; Hyacinthe, Johanna; Lambert, Justina; Lockowitz, James; Schrock, Jordan

    2015-11-01

    Although exposure to acute stress has been shown to reinstate extinguished responding for a wide variety of drugs, no studies have investigated stress-induced reinstatement in animals with a history of 3,4-methylenedioxymethamphetamine (MDMA; ecstasy) self-administration. Thus, rats were trained to press a lever for MDMA (0.50 mg/kg/infusion) in daily sessions, and lever pressing was subsequently extinguished in the absence of MDMA and conditioned cues (light and tone). We then tested the ability of acute yohimbine (2.0 mg/kg), a pharmacological stressor, to reinstate lever-pressing under extinction conditions. Additionally, to model chronic stress, some rats were injected daily with yohimbine (5.0 mg/kg × 10 days) prior to reinstatement tests. To assess dopaminergic involvement, chronic yohimbine injections were combined with injections of SCH-23390 (0.0 or 10.0 μg/kg), a dopamine D1-like receptor antagonist. In a separate experiment, rats with a history of food self-administration were treated and tested in the same way. Results showed that acute yohimbine injections reinstated extinguished MDMA and food seeking, but only in rats with a history of chronic yohimbine exposure. Co-administration of SCH-23390 with chronic yohimbine injections prevented the potentiation of subsequent food seeking, but not MDMA seeking. These results suggest that abstinent MDMA users who also are exposed to chronic stress may be at increased risk for future relapse, and also that the effects of chronic stress on relapse may be mediated by different mechanisms depending on one's drug use history. PMID:26241170

  15. Chronic myelogenous leukemia (CML)

    Science.gov (United States)

    CML; Chronic myeloid leukemia; Chronic granulocytic leukemia; Leukemia - chronic granulocytic ... nuclear disaster. It takes many years to develop leukemia from radiation exposure. Most people treated for cancer ...

  16. Chronic obstructive pulmonary disease

    Science.gov (United States)

    ... airways disease; Chronic obstructive lung disease; Chronic bronchitis; Emphysema; Bronchitis - chronic ... a protein called alpha-1 antitrypsin can develop emphysema. Other risk factors for COPD are: Exposure to ...

  17. Considerations when using longitudinal cohort studies to assess dietary exposure to inorganic arsenic and chronic health outcomes.

    Science.gov (United States)

    Scrafford, Carolyn G; Barraj, Leila M; Tsuji, Joyce S

    2016-07-01

    Dietary arsenic exposure and chronic health outcomes are of interest, due in part to increased awareness and data available on inorganic arsenic levels in some foods. Recent concerns regarding levels of inorganic arsenic, the primary form of arsenic of human health concern, in foods are based on extrapolation from adverse health effects observed at high levels of inorganic arsenic exposure; the potential for the occurrence of these health effects from lower levels of dietary inorganic arsenic exposure has not been established. In this review, longitudinal cohort studies are evaluated for their utility in estimating dietary inorganic arsenic exposure and quantifying statistically reliable associations with health outcomes. The primary limiting factor in longitudinal studies is incomplete data on inorganic arsenic levels in foods combined with the aggregation of consumption of foods with varying arsenic levels into a single category, resulting in exposure misclassification. Longitudinal cohort studies could provide some evidence to evaluate associations of dietary patterns related to inorganic arsenic exposure with risk of arsenic-related diseases. However, currently available data from longitudinal cohort studies limit causal analyses regarding the association between inorganic arsenic exposure and health outcomes. Any conclusions should therefore be viewed with knowledge of the analytical and methodological limitations. PMID:27155067

  18. NOTCH1, HIF1A and other cancer-related proteins in lung tissue from uranium miners--variation by occupational exposure and subtype of lung cancer.

    Directory of Open Access Journals (Sweden)

    Beate Pesch

    Full Text Available BACKGROUND: Radon and arsenic are established pulmonary carcinogens. We investigated the association of cumulative exposure to these carcinogens with NOTCH1, HIF1A and other cancer-specific proteins in lung tissue from uranium miners. METHODOLOGY/PRINCIPAL FINDINGS: Paraffin-embedded tissue of 147 miners was randomly selected from an autopsy repository by type of lung tissue, comprising adenocarcinoma (AdCa, squamous cell carcinoma (SqCC, small cell lung cancer (SCLC, and cancer-free tissue. Within each stratum, we additionally stratified by low or high level of exposure to radon or arsenic. Lifetime exposure to radon and arsenic was estimated using a quantitative job-exposure matrix developed for uranium mining. For 22 cancer-related proteins, immunohistochemical scores were calculated from the intensity and percentage of stained cells. We explored the associations of these scores with cumulative exposure to radon and arsenic with Spearman rank correlation coefficients (r(s. Occupational exposure was associated with an up-regulation of NOTCH1 (radon r(s = 0.18, 95% CI 0.02-0.33; arsenic: r(s = 0.23, 95% CI 0.07-0.38. Moreover, we investigated whether these cancer-related proteins can classify lung cancer using supervised and unsupervised classification. MUC1 classified lung cancer from cancer-free tissue with a failure rate of 2.1%. A two-protein signature discriminated SCLC (HIF1A low, AdCa (NKX2-1 high, and SqCC (NKX2-1 low with a failure rate of 8.4%. CONCLUSIONS/SIGNIFICANCE: These results suggest that the radiation-sensitive protein NOTCH1 can be up-regulated in lung tissue from uranium miners by level of exposure to pulmonary carcinogens. We evaluated a three-protein signature consisting of a physiological protein (MUC1, a cancer-specific protein (HIF1A, and a lineage-specific protein (NKX2-1 that could discriminate lung cancer and its major subtypes with a low failure rate.

  19. The potential immune modulatory effect of chronic bisphenol A exposure on gene regulation in male medaka (Oryzias latipes) liver.

    Science.gov (United States)

    Qiu, Wenhui; Shen, Yang; Pan, Chenyuan; Liu, Shuai; Wu, Minghong; Yang, Ming; Wang, Ke-Jian

    2016-08-01

    Bisphenol A (BPA) is a well-known estrogenic endocrine disrupting chemical (EDC) ubiquitously present in various environmental media. The present study aims to identify the responsive genes in male fish chronically exposed to low concentrations of BPA at the transcription level. We screened genes from a suppression subtractive hybridization library constructed from male medaka (Oryzias latipes) livers after 60-d exposure to 10μg/L BPA under the condition at which changes of hepatic antioxidant parameters have been previously reported. The identified genes were predicted to be involved in multiple biological processes including antioxidant physiology, endocrine system, detoxification, notably associated with the immune response processes. With real time PCR analysis, the immune-associated genes including hepcidin-like precursor, complement component and factors, MHC class I, alpha-2-macroglobulin and novel immune-type receptor 6 isoform were significantly up-regulated in a nonmonotonic dose response pattern in livers upon exposure to different concentrations of BPA (0.1, 1, 10, 100, 1000μg/L). Our results demonstrated a negative impact on gene regulation in fish chronically exposed to relatively low and environmentally relevant concentrations of BPA, and suggested the potential immune modulatory effect of chronic EDC exposure on fish. The immunotoxicity of BPA and other EDCs should be much concerned for the health of human beings and other vertebrates exposed to it. PMID:27104808

  20. Chronic intermittent ethanol exposure and withdrawal leads to adaptations in nucleus accumbens core postsynaptic density proteome and dendritic spines.

    Science.gov (United States)

    Uys, Joachim D; McGuier, Natalie S; Gass, Justin T; Griffin, William C; Ball, Lauren E; Mulholland, Patrick J

    2016-05-01

    Alcohol use disorder is a chronic relapsing brain disease characterized by the loss of ability to control alcohol (ethanol) intake despite knowledge of detrimental health or personal consequences. Clinical and pre-clinical models provide strong evidence for chronic ethanol-associated alterations in glutamatergic signaling and impaired synaptic plasticity in the nucleus accumbens (NAc). However, the neural mechanisms that contribute to aberrant glutamatergic signaling in ethanol-dependent individuals in this critical brain structure remain unknown. Using an unbiased proteomic approach, we investigated the effects of chronic intermittent ethanol (CIE) exposure on neuroadaptations in postsynaptic density (PSD)-enriched proteins in the NAc of ethanol-dependent mice. Compared with controls, CIE exposure significantly changed expression levels of 50 proteins in the PSD-enriched fraction. Systems biology and functional annotation analyses demonstrated that the dysregulated proteins are expressed at tetrapartite synapses and critically regulate cellular morphology. To confirm this latter finding, the density and morphology of dendritic spines were examined in the NAc core of ethanol-dependent mice. We found that CIE exposure and withdrawal differentially altered dendrite diameter and dendritic spine density and morphology. Through the use of quantitative proteomics and functional annotation, these series of experiments demonstrate that ethanol dependence produces neuroadaptations in proteins that modify dendritic spine morphology. In addition, these studies identified novel PSD-related proteins that contribute to the neurobiological mechanisms of ethanol dependence that drive maladaptive structural plasticity of NAc neurons. PMID:25787124

  1. Uranium-induced sensory alterations in the zebrafish Danio rerio

    International Nuclear Information System (INIS)

    The effect of chronic exposure to uranium ions (UO22+) on sensory tissues including the olfactory and lateral line systems was investigated in zebrafish (Danio rerio) using scanning electron microscopy. The aim of this study was to determine whether exposure to uranium damaged sensory tissues in fish. The fish were exposed to uranium at the concentration of 250 μg l−1 for 10 days followed by a depuration period of 23 days. Measurements of uranium uptake in different fish organs: olfactory rosettes and bulbs, brain, skin, and muscles, were also determined by ICP-AES and ICP-MS during the entire experimental period. The results showed that uranium displayed a strong affinity for sensory structures in direct contact with the surrounding medium, such as the olfactory and lateral line systems distributed on the skin. A decreasing gradient of uranium concentration was found: olfactory rosettes > olfactory bulbs > skin > muscles > brain. At the end of the experiment, uranium was present in non-negligible quantities in sensory tissues. In parallel, fish exposed to uranium showed severe sensory tissue alterations at the level of the olfactory and lateral line systems. In both sensory systems, the gross morphology was altered and the sensory hair cells were significantly damaged very early after the initiation of exposure (from the 3rd day). At the end of the experiment, after 23 days of depuration, the lateral line system still displayed slight tissue alterations, but approximately 80% of the neuromasts in this system had regenerated. In contrast, the olfactory system took more time to recover, as more than half of the olfactory rosettes observed remained destroyed at the end of the experiment. This study showed, for the first time, that uranium is able to damage fish sensory tissues to such an extent that tissue regeneration is delayed.

  2. Uranium-induced sensory alterations in the zebrafish Danio rerio

    Energy Technology Data Exchange (ETDEWEB)

    Faucher, K., E-mail: kfaucher@hotmail.fr [Laboratoire d' ecotoxicologie des radionucleides (LECO), Institut de Radioprotection et Surete Nucleaire, Centre de Cadarache, Batiment 186, BP3, 13115 Saint Paul lez Durance (France); Floriani, M.; Gilbin, R.; Adam-Guillermin, C. [Laboratoire d' ecotoxicologie des radionucleides (LECO), Institut de Radioprotection et Surete Nucleaire, Centre de Cadarache, Batiment 186, BP3, 13115 Saint Paul lez Durance (France)

    2012-11-15

    The effect of chronic exposure to uranium ions (UO{sub 2}{sup 2+}) on sensory tissues including the olfactory and lateral line systems was investigated in zebrafish (Danio rerio) using scanning electron microscopy. The aim of this study was to determine whether exposure to uranium damaged sensory tissues in fish. The fish were exposed to uranium at the concentration of 250 {mu}g l{sup -1} for 10 days followed by a depuration period of 23 days. Measurements of uranium uptake in different fish organs: olfactory rosettes and bulbs, brain, skin, and muscles, were also determined by ICP-AES and ICP-MS during the entire experimental period. The results showed that uranium displayed a strong affinity for sensory structures in direct contact with the surrounding medium, such as the olfactory and lateral line systems distributed on the skin. A decreasing gradient of uranium concentration was found: olfactory rosettes > olfactory bulbs > skin > muscles > brain. At the end of the experiment, uranium was present in non-negligible quantities in sensory tissues. In parallel, fish exposed to uranium showed severe sensory tissue alterations at the level of the olfactory and lateral line systems. In both sensory systems, the gross morphology was altered and the sensory hair cells were significantly damaged very early after the initiation of exposure (from the 3rd day). At the end of the experiment, after 23 days of depuration, the lateral line system still displayed slight tissue alterations, but approximately 80% of the neuromasts in this system had regenerated. In contrast, the olfactory system took more time to recover, as more than half of the olfactory rosettes observed remained destroyed at the end of the experiment. This study showed, for the first time, that uranium is able to damage fish sensory tissues to such an extent that tissue regeneration is delayed.

  3. Uncertainty and sensitivity analysis of chronic exposure results with the MACCS reactor accident consequence model

    International Nuclear Information System (INIS)

    Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling, partial correlation analysis and stepwise regression analysis are used in an investigation with the MACCS model of the chronic exposure pathways associated with a severe accident at a nuclear power station. The primary purpose of this study is to provide guidance on the variables to be considered in future review work to reduce the uncertainty in the important variables used in the calculation of reactor accident consequences. The effects of 75 imprecisely known input variables on the following reactor accident consequences are studied: crop growing season dose, crop long-term dose, water ingestion dose, milk growing season dose, long-term groundshine dose, long-term inhalation dose, total food pathways dose, total ingestion pathways dose, total long-term pathways dose, total latent cancer fatalities, area-dependent cost, crop disposal cost, milk disposal cost, population-dependent cost, total economic cost, condemnation area, condemnation population, crop disposal area and milk disposal area. When the predicted variables are considered collectively, the following input variables were found to be the dominant contributors to uncertainty: dry deposition velocity, transfer of cesium from animal feed to milk, transfer of cesium from animal feed to meat, ground concentration of Cs-134 at which the disposal of milk products will be initiated, transfer of Sr-90 from soil to legumes, maximum allowable ground concentration of Sr-90 for production of crops, fraction of cesium entering surface water that is consumed in drinking water, groundshine shielding factor, scale factor defining resuspension, dose reduction associated with decontamination, and ground concentration of 1-131 at which disposal of crops will be initiated due to accidents that occur during the growing season

  4. Effect of chronic pesticide exposure in farm workers of a Mexico community.

    Science.gov (United States)

    Payán-Rentería, Rolando; Garibay-Chávez, Guadalupe; Rangel-Ascencio, Raul; Preciado-Martínez, Veronica; Muñoz-Islas, Laura; Beltrán-Miranda, Claudia; Mena-Munguía, Salvador; Jave-Suárez, Luis; Feria-Velasco, Alfredo; De Celis, Ruth

    2012-01-01

    Pesticides are frequently used substances worldwide, even when the use of some of them is forbidden due to the recognized adverse effect they have on the health of not only the people who apply the pesticides, but also of those that consume the contaminated products. The objectives of this study were to know the health issues of farm workers chronically exposed to pesticides, to evaluate possible damage at genetic level, as well as to explore some hepatic, renal, and hematological alterations. A transversal comparative study was performed between 2 groups, one composed of 25 farm workers engaged in pesticide spraying, and a control group of 21 workers not exposed to pesticides; both groups belonged to the Nextipac community in Jalisco, Mexico. Each member of both groups underwent a full medical history. Blood samples were taken from all farm workers in order to obtain a complete blood count and chemistry, clinical chemistry, lipid profile, liver and kidney function tests, erythrocyte cholinesterase quantification, lipid peroxidation profile, and free DNA fragment quantification. For the information analysis, central tendency and dispersion measurements were registered. In order to know the differences between groups, a cluster multivariate method was used, as well as prevalence reasons. The most used pesticides were mainly organophosphates, triazines and organochlorine compounds. The exposed group showed acute poisoning (20% of the cases) and diverse alterations of the digestive, neurological, respiratory, circulatory, dermatological, renal, and reproductive system probably associated to pesticide exposure. More importantly, they presented free DNA fragments in plasma (90.8 vs 49.05 ng/mL) as well as a higher level of lipid peroxidation (41.85 vs. 31.91 nmol/mL) in comparison with those data from unexposed farm workers. These results suggest that there exist health hazards for those farm workers exposed to pesticides, at organic and cellular levels. PMID:22315932

  5. Uncertainty and sensitivity analysis of chronic exposure results with the MACCS reactor accident consequence model

    International Nuclear Information System (INIS)

    Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling, partial correlation analysis and stepwise regression analysis are used in an investigation with the MACCS model of the chronic exposure pathways associated with a severe accident at a nuclear power station. The primary purpose of this study is to provide guidance on the variables to be considered in future review work to reduce the uncertainty in the important variables used in the calculation of reactor accident consequences. The effects of 75 imprecisely known input variables on the following reactor accident consequences are studied: crop growing-season dose, crop long-term dose, water ingestion dose, milk growing-season dose, long-term groundshine dose, long-term inhalation dose, total food pathways dose, total ingestion pathways dose, total long-term pathways dose, total latent cancer fatalities, area-dependent cost, crop disposal cost, milk disposal cost, population-dependent cost, total economic cost, condemnation area, condemnation population, crop disposal area and milk disposal area. When the predicted variables are considered collectively, the following input variables were found to be the dominant contributors to uncertainty: dry deposition velocity, transfer of cesium from animal feed to milk, transfer of cesium from animal feed to meet, ground concentration of Cs-134 at which the disposal of milk products will be initiated, transfer of Sr-90 from soil to legumes, maximum allowable ground concentration of Sr-90 for production of crops, fraction of cesium entering surface water that is consumed in drinking water, groundshine shielding factor, scale factor defining resuspension, dose reduction associated with decontamination, and ground concentration of I-131 at which disposal of crops will be initiated due to accidents that occur during the growing season. Reducing the uncertainty in the preceding variables was found to substantially reduce the uncertainty in the

  6. Micronucleus assay in human lymphocytes as a bio dosimeter of in vivo acute and chronic exposures

    International Nuclear Information System (INIS)

    To assess the persistence over time of micronuclei (MN) in lymphocytes of cancer patients after radiotherapy and, consequently, to verify the suitability of MN test as a dosimeter for monitoring in vivo ionizing radiation damage, the cytokinesis-blocked MN assay was applied in peripheral blood lymphocytes of cervix and head and neck cancer patients (n = 34). The evaluation of data suggests that: 1) MN frequency increases linearly with the equivalent total-body absorbed dose (R2 = 0,9; P=0,015); 2) The distribution of the MN yields deviates significantly from Poisson with the increase of equivalent total-body dose (σ2/y = 1,14 mean value); 3) The comparison of spontaneous MN frequencies in healthy subjects with those in cancer patients, prior to radiotherapy, shows significant differences (p<0,01); and 4) It is observed a general decline in MN frequencies with time after radiotherapy, with considerable variations between patients. The kinetics of elimination of MN seems to follow a two-term exponential function, with a short and a long term. Patients with the highest equivalent total-body dose (total tumoral dose: 60-80 Gy) initially tend to have the fastest decline. At 6-18 months of follow-up time 11 of the 17 patients, evaluated 2-480 months post-treatment, showed higher frequencies of MN than their respective levels before radiation therapy, indicating persistence of radiation induced cytogenetic damage. Further studies modeling changes in chromosome aberrations with acute and chronic exposures should provide perspectives on biological dosimetry in accident situations in which there is a blood sampling delay and on biological monitoring of human populations exposed to ionizing radiation. (author)

  7. Uncertainty and sensitivity analysis of chronic exposure results with the MACCS reactor accident consequence model

    Energy Technology Data Exchange (ETDEWEB)

    Helton, J.C. [Arizona State Univ., Tempe, AZ (United States); Johnson, J.D.; Rollstin, J.A. [Gram, Inc., Albuquerque, NM (United States); Shiver, A.W.; Sprung, J.L. [Sandia National Labs., Albuquerque, NM (United States)

    1995-01-01

    Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling, partial correlation analysis and stepwise regression analysis are used in an investigation with the MACCS model of the chronic exposure pathways associated with a severe accident at a nuclear power station. The primary purpose of this study is to provide guidance on the variables to be considered in future review work to reduce the uncertainty in the important variables used in the calculation of reactor accident consequences. The effects of 75 imprecisely known input variables on the following reactor accident consequences are studied: crop growing season dose, crop long-term dose, water ingestion dose, milk growing season dose, long-term groundshine dose, long-term inhalation dose, total food pathways dose, total ingestion pathways dose, total long-term pathways dose, total latent cancer fatalities, area-dependent cost, crop disposal cost, milk disposal cost, population-dependent cost, total economic cost, condemnation area, condemnation population, crop disposal area and milk disposal area. When the predicted variables are considered collectively, the following input variables were found to be the dominant contributors to uncertainty: dry deposition velocity, transfer of cesium from animal feed to milk, transfer of cesium from animal feed to meat, ground concentration of Cs-134 at which the disposal of milk products will be initiated, transfer of Sr-90 from soil to legumes, maximum allowable ground concentration of Sr-90 for production of crops, fraction of cesium entering surface water that is consumed in drinking water, groundshine shielding factor, scale factor defining resuspension, dose reduction associated with decontamination, and ground concentration of 1-131 at which disposal of crops will be initiated due to accidents that occur during the growing season.

  8. Hereditary effects of low and chronic radiation exposure: a case-control study of mental retardation and cleft lip/palate in the monazite bearing coastal areas of Southern Kerala

    International Nuclear Information System (INIS)

    The high level natural radiation (HLNR) areas of Kerala in the south west coast of Kerala is suitable for direct human studies to assess the genetic and teratogenic effect of low and chronic radiation exposures. The radiation level in the region (about 55 km long and 0.5 km wide belt) range from ≤1.0 mGy to 45.0 mGy per year and is due to natural deposit of monazite sand containing Thorium (8-10%), Uranium (0.3%) and corresponding decay products. A population based case-control study was carried out in the area to assess the role, if any, of HLNR as a causative factor in the etiology of two relatively frequent and easily identifiable congenital malformations, viz., mental retardation (MR) and cleft lip/palate (CLP). Findings from the study are discussed in this paper

  9. Evaluation of a Po-210 bioassay as an index of the exposure of uranium mine workers in Japan to radon daughters

    International Nuclear Information System (INIS)

    As an indicator nuclide for inhalation exposure of mine workders to Rn daughters in a Japanses uranium mine, 210Po urinalyses of the workers and surveys of some environmental factors were conducted. An estimation study of concentrations of Rn daughters in a mine, indicated that about 800-50 pCi of 210Po could have been accumulated in each miner's body. However, according to the results of urinalyses performed several times in 5 years, a statistical difference in the quantity of 210Po in urine among miners and non-mining workers there was not clearly identified. Investigations of 210Po concentrations in the mine's air, water, foods (of about 30 kinds) and cigarets, and investigations of feces-urine 210Po ratios in humans revealed that these factors would greatly affect the metabolism and 210Po excretion of the workers. In particular, some marine foods in Japan contained a great amount of 210Po (several hundreds times that of other foods) and cigarets showed 0.3-0.8 pCi of 210Po per gramme. Smokers definitely excreted more 210Po in urine than non-smokers. Feces-urine ratios ranged between 5.2-42.9 in one human subject. Therefore, it can be concluded that 210Po would not be a good indicator for human exposure to Rn daughters, unless great care is taken regarding the eating and smoking habits of mine workers, as well as the exposure conditions in the uranium mine. (Evans, J.)

  10. The acute and sub-chronic exposures of goldfish to naphthenic acids induce different host defense responses.

    Science.gov (United States)

    Hagen, Mariel O; Garcia-Garcia, Erick; Oladiran, Ayoola; Karpman, Matthew; Mitchell, Scott; El-Din, Mohamed Gamal; Martin, Jonathan W; Belosevic, Miodrag

    2012-03-01

    Naphthenic acids (NAs) are believed to be the major toxic component in oil sands process-affected water (OSPW) produced by the oil sands mining industry in Northern Alberta, Canada. We recently reported that oral exposure to NAs alters mammalian immune responses, but the effect of OSPW or NAs on the immune mechanisms of aquatic organisms has not been fully elucidated. We analyzed the effects of acute and sub-chronic NAs exposures on goldfish immune responses by measuring the expression of three pro-inflammatory cytokine genes, antimicrobial functions of macrophages, and host defense after challenge with a protozoan pathogen (Trypanosoma carassii). One week after NAs exposure, fish exhibited increased expression of pro-inflammatory cytokines (IFNγ, IL-1β1, TNF-α2) in the gills, kidney and spleen. Primary macrophages from fish exposed to NAs for one week, exhibited increased production of nitric oxide and reactive oxygen intermediates. Goldfish exposed for one week to 20 mg/L NAs were more resistant to infection by T. carassii. In contrast, sub-chronic exposure of goldfish (12 weeks) to NAs resulted in decreased expression of pro-inflammatory cytokines in the gills, kidney and spleen. The sub-chronic exposure to NAs reduced the ability of goldfish to control the T. carassii infection, exemplified by a drastic increase in fish mortality and increased blood parasite loads. This is the first report analyzing the effects of OSPW contaminants on the immune system of aquatic vertebrates. We believe that the bioassays depicted in this work will be valuable tools for analyzing the efficacy of OSPW remediation techniques and assessment of diverse environmental pollutants. PMID:22227375

  11. Chronic uranium contamination alters spinal motor neuron integrity via modulation of SMN1 expression and microglia recruitment.

    Science.gov (United States)

    Saint-Marc, Brice; Elie, Christelle; Manens, Line; Tack, Karine; Benderitter, Marc; Gueguen, Yann; Ibanez, Chrystelle

    2016-07-01

    Consequences of uranium contamination have been extensively studied in brain as cognitive function impairments were observed in rodents. Locomotor disturbances have also been described in contaminated animals. Epidemiological studies have revealed increased risk of motor neuron diseases in veterans potentially exposed to uranium during their military duties. To our knowledge, biological response of spinal cord to uranium contamination has not been studied even though it has a crucial role in locomotion. Four groups of rats were contaminated with increasing concentrations of uranium in their drinking water compared to a control group to study cellular mechanisms involved in locomotor disorders. Nissl staining of spinal cord sections revealed the presence of chromatolytic neurons in the ventral horn. This observation was correlated with a decreased number of motor neurons in the highly contaminated group and a decrease of SMN1 protein expression (Survival of Motor Neuron 1). While contamination impairs motor neuron integrity, an increasing number of microglial cells indicates the trigger of a neuroinflammation process. Potential overexpression of a microglial recruitment chemokine, MCP-1 (Monocyte Chimioattractant Protein 1), by motor neurons themselves could mediate this process. Studies on spinal cord appear to be relevant for risk assessment of population exposed via contaminated food and water. PMID:27153795

  12. Gamma exposure rate reduction and residual radium-226 concentrations resulting from decontamination activities conducted at the former uranium millsite in Shiprock, New Mexico

    International Nuclear Information System (INIS)

    Gamma radiation surveys and residual radium 226 soil samples were taken as part of the decontamination activities of the former Shiprock uranium mill site in New Mexico. In order to facilitate the decontamination activities, the mill site and its contaminated environs were divided into 6 major areas. Extensive data are presented in 2 appendices of the pre- and post-decontamination gamma ray exposure rates made on mill site, and of radium 226 concentrations in surface soil samples. A training program established on the mill site by the Navajo Engineering and Construction Authority is described

  13. Gene expression and pathologic alterations in juvenile rainbow trout due to chronic dietary TCDD exposure

    International Nuclear Information System (INIS)

    Highlights: •First report of the effects of dietary TCDD in juvenile trout smaller than 20 g. •TCDD uptake was estimated using published models and confirmed by GC. •First report of dietary TCDD-induced lesions in nasal epithelium in any species. •Several useful biomarkers are identified from microarray-based transcriptomics analysis. -- Abstract: The goal of this project was to use functional genomic methods to identify molecular biomarkers as indicators of the impact of TCDD exposure in rainbow trout. Specifically, we investigated the effects of chronic dietary TCDD exposure on whole juvenile rainbow trout global gene expression associated with histopathological analysis. Juvenile rainbow trout were fed Biodiet starter with TCDD added at 0, 0.1, 1, 10 and 100 ppb (ng TCDD/g food), and fish were sampled from each group at 7, 14, 28 and 42 days after initiation of feeding. 100 ppb TCDD caused 100% mortality at 39 days. Fish fed with 100 ppb TCDD food had TCDD accumulation of 47.37 ppb (ng TCDD/g fish) in whole fish at 28 days. Histological analysis from TCDD-treated trout sampled from 28 and 42 days revealed that obvious lesions were found in skin, oropharynx, liver, gas bladder, intestine, pancreas, nose and kidney. In addition, TCDD caused anemia in peripheral blood, decreases in abdominal fat, increases of remodeling of fin rays, edema in pericardium and retrobulbar hemorrhage in the 100 ppb TCDD-treated rainbow trout compared to the control group at 28 days. Dose- and time-dependent global gene expression analyses were performed using the cGRASP 16,000 (16K) cDNA microarray. TCDD-responsive whole body transcripts identified in the microarray experiments have putative functions involved in various biological processes including growth, cell proliferation, metabolic process, and immune system processes. Nine microarray-identified genes were selected for QPCR validation. CYP1A3 and CYP1A1 were common up-regulated genes and HBB1 was a common down

  14. Gene expression and pathologic alterations in juvenile rainbow trout due to chronic dietary TCDD exposure

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qing [Department of Biological Sciences, University of Wisconsin-Milwaukee, Lapham Hall, 3209 N. Maryland Ave., Milwaukee, WI 53211 (United States); School of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 E Greenfield Ave, Milwaukee, WI 53204 (United States); Rise, Matthew L. [Ocean Sciences Centre, Memorial University of Newfoundland, 1 Marine Lab Road, St. John' s, NL, A1C 5S7 (Canada); Spitsbergen, Jan M. [Department of Microbiology, Oregon State University, 220 Nash Hall, Corvallis, OR 97331 (United States); Hori, Tiago S. [Ocean Sciences Centre, Memorial University of Newfoundland, 1 Marine Lab Road, St. John' s, NL, A1C 5S7 (Canada); Mieritz, Mark; Geis, Steven [Wisconsin State Laboratory of Hygiene, 465 Henry Mall, Madison, WI 53706 (United States); McGraw, Joseph E. [School of Pharmacy, Concordia University Wisconsin, 12800 North Lake Shore Drive, Mequon, WI 53097 (United States); Goetz, Giles [School of Aquatic and Fishery Sciences, University of Washington, 1122 Northeast Boat Street, Seattle, WA 98195 (United States); Larson, Jeremy; Hutz, Reinhold J. [Department of Biological Sciences, University of Wisconsin-Milwaukee, Lapham Hall, 3209 N. Maryland Ave., Milwaukee, WI 53211 (United States); Carvan, Michael J., E-mail: carvanmj@uwm.edu [Department of Biological Sciences, University of Wisconsin-Milwaukee, Lapham Hall, 3209 N. Maryland Ave., Milwaukee, WI 53211 (United States); School of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 E Greenfield Ave, Milwaukee, WI 53204 (United States)

    2013-09-15

    Highlights: •First report of the effects of dietary TCDD in juvenile trout smaller than 20 g. •TCDD uptake was estimated using published models and confirmed by GC. •First report of dietary TCDD-induced lesions in nasal epithelium in any species. •Several useful biomarkers are identified from microarray-based transcriptomics analysis. -- Abstract: The goal of this project was to use functional genomic methods to identify molecular biomarkers as indicators of the impact of TCDD exposure in rainbow trout. Specifically, we investigated the effects of chronic dietary TCDD exposure on whole juvenile rainbow trout global gene expression associated with histopathological analysis. Juvenile rainbow trout were fed Biodiet starter with TCDD added at 0, 0.1, 1, 10 and 100 ppb (ng TCDD/g food), and fish were sampled from each group at 7, 14, 28 and 42 days after initiation of feeding. 100 ppb TCDD caused 100% mortality at 39 days. Fish fed with 100 ppb TCDD food had TCDD accumulation of 47.37 ppb (ng TCDD/g fish) in whole fish at 28 days. Histological analysis from TCDD-treated trout sampled from 28 and 42 days revealed that obvious lesions were found in skin, oropharynx, liver, gas bladder, intestine, pancreas, nose and kidney. In addition, TCDD caused anemia in peripheral blood, decreases in abdominal fat, increases of remodeling of fin rays, edema in pericardium and retrobulbar hemorrhage in the 100 ppb TCDD-treated rainbow trout compared to the control group at 28 days. Dose- and time-dependent global gene expression analyses were performed using the cGRASP 16,000 (16K) cDNA microarray. TCDD-responsive whole body transcripts identified in the microarray experiments have putative functions involved in various biological processes including growth, cell proliferation, metabolic process, and immune system processes. Nine microarray-identified genes were selected for QPCR validation. CYP1A3 and CYP1A1 were common up-regulated genes and HBB1 was a common down

  15. Chronic Exposure to Deoxynivalenol Has No Influence on the Oral Bioavailability of Fumonisin B1 in Broiler Chickens

    Science.gov (United States)

    Antonissen, Gunther; Devreese, Mathias; Van Immerseel, Filip; De Baere, Siegrid; Hessenberger, Sabine; Martel, An; Croubels, Siska

    2015-01-01

    Both deoxynivalenol (DON) and fumonisin B1 (FB1) are common contaminants of feed. Fumonisins (FBs) in general have a very limited oral bioavailability in healthy animals. Previous studies have demonstrated that chronic exposure to DON impairs the intestinal barrier function and integrity, by affecting the intestinal surface area and function of the tight junctions. This might influence the oral bioavailability of FB1, and possibly lead to altered toxicity of this mycotoxin. A toxicokinetic study was performed with two groups of 6 broiler chickens, which were all administered an oral bolus of 2.5 mg FBs/kg BW after three-week exposure to either uncontaminated feed (group 1) or feed contaminated with 3.12 mg DON/kg feed (group 2). No significant differences in toxicokinetic parameters of FB1 could be demonstrated between the groups. Also, no increased or decreased body exposure to FB1 was observed, since the relative oral bioavailability of FB1 after chronic DON exposure was 92.2%. PMID:25690690

  16. In vivo screening of proteins likely to bind uranium in exposed rat kidney

    International Nuclear Information System (INIS)

    Uranium is a naturally abundant element which has been used in several industries. Internal exposure could occur via three main pathways that are ingestion, inhalation and wounds. It has been recently shown that chronic ingestion of uranium in drinking water induces an important uranium accumulation in kidney with a perturbation of iron metabolism in this organ. Whereas uranium speciation is a key parameter to elucidate the chemical reactivity and the mobility of an element, it remains poorly documented in most of environmental and biological media. A few examples of uranium complexation with biomolecules have been published recently but most of them are in vitro studies whereas in vivo experiments remain poorly investigated. In order to better understand possible competition of uranium towards metals involved in the metal-protein binding, i.e. iron, copper, calcium, a study on uranium speciation was investigated by doing an in vivo screening of target proteins likely to bind it in kidneys of exposed rats. Rats were chronically exposed via contaminated drinking water at 40 mgL-1 and killed 9 months after the beginning of exposure. Kidneys were dissected out and protein extract was prepared. Then, separation of renal proteins by isoelectric focusing gel electrophoresis (IEF) and two-dimensional gel electrophoresis (2-DE) followed by LA-ICPMS analysis were performed. IEF-LA-ICP MS showed that uranium could specifically bind few proteins in kidney whereas 2-DE-LA-ICP MS could indicate that uranium is not covalently bound to proteins in this organ. The results suggested that even at moderate concentrations of exposure, uranium can be observed chelated with some renal proteins that is very encouraging to understand the entry, storage and elimination of this element in kidneys. (orig.)

  17. Developmental effects induced by chronic and prolonged exposure of chicken embryos to 900 MHz GSM base station radiation

    International Nuclear Information System (INIS)

    Interference from base station radiation with embryonic development was investigated by chronic and prolonged exposure of developing chicken embryos. The latter were exposed under a 900 MHz GSM base station radiating microwaves at recommended safety level, i.e., 41 V/m. Total death rate was 7.7 times higher among radiation exposed embryos (78.5%) than among sham exposures (10.2%). Radiation exposure was associated with delayed hatching (3.2 days) and slightly but significantly increased (P<0.01) weight of hatchings. These finding indicated that base station radiation can induce lethal effect, as well as developmental retardation. They arouse questioning as to the adequacy of current safety guidelines. (author)

  18. Zebrafish gene expression, histology, blood domoic acid level, and behavioral data (Effects of Chronic Domoic Acid Exposure on Gene Expression in the Vertebrate CNS.)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The potential impacts of chronic algal toxin exposure have long been a concern. One HAB toxin, domoic acid (DA), is a potent neurotoxin that interacts with the...

  19. Expression of Glutamatergic Genes in Healthy Humans across 16 Brain Regions; Altered Expression in the Hippocampus after Chronic Exposure to Alcohol or Cocaine

    OpenAIRE

    Enoch, Mary-Anne; Rosser, Alexandra A.; Zhou, Zhifeng; Mash, Deborah C; Yuan, Qiaoping; Goldman, David

    2014-01-01

    We analyzed global patterns of expression in genes related to glutamatergic neurotransmission (glutamatergic genes) in healthy human adult brain before determining the effects of chronic alcohol and cocaine exposure on gene expression in the hippocampus.

  20. Effects of sub-chronic exposure to SO{sub 2} on lipid and carbohydrate metabolism in rats

    Energy Technology Data Exchange (ETDEWEB)

    Lovati, M.R. [Institute of Pharmacological Sciences, Milan (Italy); Manzoni, C. [Institute of Pharmacological Sciences, Milan (Italy); Daldossi, M. [Institute of Pharmacological Sciences, Milan (Italy); Spolti, S. [Institute of Pharmacological Sciences, Milan (Italy); Sirtori, C.R. [Institute of Pharmacological Sciences, Milan (Italy)

    1996-01-01

    Sulfur dioxide (SO{sub 2}) is a ubiquitous air pollutant, present in low concentrations in the urban air, and in higher concentrations in the working environment. While toxicological reports on SO{sub 2} have extensively dealt with the pulmonary system, essentially no data are available on the effects of chronic exposure to this pollutant on intermediary metabolism, although some biochemical changes in lipid metabolism have been detected. The present investigation was aimed at evaluating the effects of sub-chronic exposure to SO{sub 2} on concentrations of serum lipids/lipoproteins and on glucose metabolism, in animal models of hypercholesterolemia and diabetes. A specially designed controlinert atmosphere chamber was used, where male Sprague-Dawley rats fed on either standard or cholesterol enriched (HC) diets, as well as streptozotocin diabetics, were exposed to SO{sub 2} at 5 and 10 ppm, 24 h per day for 14 days. In rats, both on a standard diet and on a HC regimen, SO{sub 2} exposure determined a significant dose-dependent increase in plasma triglycerides, up to +363% in the 10 ppm HC exposed animals. This same gas concentration significantly reduced HDL cholesterol levels. In contrast, exposure of diabetic animals to 10 ppm SO{sub 2} resulted in a fall (-41%) of plasma and liver triglycerides and in a concomitant increase (+62%) of plasma HDL cholesterol. This discrepancy could apparently be related to diverging effects of SO{sub 2} exposure on plasma insulin levels in the different animal groups. Kinetic analyses of triglyceride synthesis carried out in rats on a standard diet revealed, in exposed animals, a significant reduction in the secretory rate, in spite of the concomitant hypertriglyceridemia. These findings suggest that SO{sub 2} exposure can markedly modify major lipid and glycemic indices, also indicating a differential response in normo/hyperlipidemic versus diabetic animals. (orig.)

  1. Metabolism of Mycotoxins, Intracellular Functions of Vitamin B12, and Neurological Manifestations in Patients with Chronic Toxigenic Mold Exposures. A Review

    OpenAIRE

    Ebere C. Anyanwu; Mohammed Morad; Campbell, Andrew W.

    2004-01-01

    This paper evaluates the possible reasons for consistent vitamin B12 deficiency in chronic toxigenic mold exposures and the synergistic relationships with the possible mycotoxic effects on one-carbon metabolism that lead to the manifestations of clinical neuropathological symptomology. Vitamins are first defined in general and the nutritional sources of vitamin B12 are evaluated in particular. Since patients with chronic exposures to toxigenic molds manifest vitamin B12 deficiencies, the role...

  2. Hair analysis following chronic smoked-drugs-of-abuse exposure in adults and their toddler: a case report

    Directory of Open Access Journals (Sweden)

    Papaseit Esther

    2011-12-01

    Full Text Available Abstract Introduction Over the past two decades, the study of chronic cocaine and crack cocaine exposure in the pediatric population has been focused on the potential adverse effects, especially in the prenatal period and early childhood. Non-invasive biological matrices have become an essential tool for the assessment of a long-term history of drug of abuse exposure. Case report We analyze the significance of different biomarker values in hair after chronic crack exposure in a two-year-old Caucasian girl and her parents, who are self-reported crack smokers. The level of benzoylecgonine, the principal metabolite of cocaine, was determined in segmented hair samples (0 cm to 3 cm from the scalp, and > 3 cm from the scalp following washing to exclude external contamination. Benzoylecgonine was detectable in high concentrations in the child's hair, at 1.9 ng/mg and 7.04 ng/mg, respectively. Benzoylecgonine was also present in the maternal and paternal hair samples at 7.88 ng/mg and 6.39 ng/mg, and 13.06 ng/mg and 12.97 ng/mg, respectively. Conclusion Based on the data from this case and from previously published poisoning cases, as well as on the experience of our research group, we conclude that, using similar matrices for the study of chronic drug exposure, children present with a higher cocaine concentration in hair and they experience more serious deleterious acute effects, probably due to a different and slower cocaine metabolism. Consequently, children must be not exposed to secondhand crack smoke under any circumstance.

  3. Accumulation and effects of Cr(VI) in Japanese medaka (Oryzias latipes) during chronic dissolved and dietary exposures.

    Science.gov (United States)

    Chen, Hongxing; Mu, Lei; Cao, Jinling; Mu, Jingli; Klerks, Paul L; Luo, Yongju; Guo, Zhongbao; Xie, Lingtian

    2016-07-01

    Chromium (Cr) is an essential metal and a nutritional supplement for both human and agricultural uses. It is also a pollutant from a variety of industrial uses. These uses can lead to elevated Cr levels in aquatic environments, where it can enter and affect aquatic organisms. Its accumulation and subsequent effects in fish have received relatively little attention, especially for chronic exposure. In the present study, Japanese medaka were chronically exposed to dissolved or dietary Cr(VI) for 3 months. Cr accumulation in liver, gills, intestine, and brain was evaluated. Effects on the antioxidant system, nervous system (acetylcholinesterase, AChE), digestive system (α-glucosidase, α-Glu), and tissue histology (liver and gills) were also assessed. Cr accumulation was observed in the intestine and liver of fish exposed to Cr-contaminated brine shrimp. However, chronic dissolved Cr exposure led to significant Cr accumulation in all organs tested. Analysis of the subcellular distribution of Cr in medaka livers revealed that 37% of the Cr was present in the heat stable protein fraction. The dissolved Cr exposure had pronounced effects on the antioxidant system in the liver, with an elevated ratio of reduced glutathione/oxidized glutathione (GSH/GSSG) and decreases in GSH and glutathione S-transferase (GST). The α-Glu activity in the intestine was significantly inhibited. In addition, Cr exposure caused histopathological alterations in the gills and liver. In general, the effects of dietary Cr were relatively minor, possible due to the much lower accumulation in the fish. Our results imply that Japanese medaka accumulate Cr mainly via uptake of dissolved Cr(VI). PMID:27162070

  4. Chronic environmental exposure to lead affects semen quality in a Mexican men population

    Science.gov (United States)

    Morán-Martínez, Javier; Carranza-Rosales, Pilar; Morales-Vallarta, Mario; A. Heredia-Rojas, José; Bassol-Mayagoitia, Susana; Denys Betancourt-Martínez, Nadia; M. Cerda-Flores, Ricardo

    2013-01-01

    Background: Male infertility is affected by several factors. Lead is one of the heavy metals more bioavailable than usually modifies the sperm quality in humans. Objective: The aim of this study was to establish the role of lead in semen quality in environmentally exposed men. Materials and Methods: Semen and blood samples were obtained from two groups: the exposed group (EG=20) and the non-exposed group (NEG=27). Two semen aliquots were used, one to evaluate spermatic quality and the other for lead determination. Blood (PbB) and semen lead (PbS) determination was performed by atomic absorption spectrophotometry. Results: The PbB concentration was significantly greater in the EG, 10.10±0.97 µgdL-1 than in the NEG, 6.42±0.38 µgdL-1 (p<0.01), as well as the PbS concentration, with 3.28±0.35 and 1.76±0.14µgdL-1 in the EG and NEG respectively (p=0.043). A significant correlation between PbS and PbB concentration in the EG was found (r=0.573, p=0.038). Overall, the spermatic quality was lower in the EG than in the NEG. Specifically, there were significant differences in the spermatic concentration [EG=43.98±6.26 and NEG=68.78±8.51X106 cellmL-1 (p<0.01)], motility [EG=49±7 and NEG=67±4% (p=0.029)], viability [EG=36.32±3.59 and NEG=72.12±1.91% (p<0.01)] and abnormal morphology [EG=67±18 and NEG=32±12% (p<0.01)]. In the immature germ cells (IGC) concentration differences were found only for A cells (EG=8.1±1.1x100 and NEG=3.2±1.9X100 spermatozoa) (p<0.01) and for Sab cells (EG=3.4±2.2x100 and NEG=1.1±1.0X100 spermatozoa) (p=0.041). Conclusion: These results suggest that chronic environmental exposure to low levels of lead adversely affect the spermatic quality. PMID:24639755

  5. Neuropsychological effects of chronic low-dose exposure to polychlorinated biphenyls (PCBs: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Klett Martin

    2005-10-01

    Full Text Available Abstract Background Exposure to indoor air of private or public buildings contaminated with polychlorinated biphenyls (PCBs has raised health concerns in long-term users. This exploratory neuropsychological group study investigated the potential adverse effects of chronic low-dose exposure to specific air-borne low chlorinated PCBs on well-being and behavioral measures in adult humans. Methods Thirty employees exposed to indoor air contaminated with PCBs from elastic sealants in a school building were compared to 30 non-exposed controls matched for education and age, controlling for gender (age range 37–61 years. PCB exposure was verified by external exposure data and biological monitoring (PCB 28, 101, 138, 153, 180. Subjective complaints, learning and memory, executive function, and visual-spatial function was assessed by standardized neuropsychological testing. Since exposure status depended on the use of contaminated rooms, an objectively exposed subgroup (N = 16; PCB 28 = 0.20 μg/l; weighted exposure duration 17.9 ± 7 years was identified and compared with 16 paired controls. Results Blood analyses indicated a moderate exposure effect size (d relative to expected background exposure for total PCB (4.45 ± 2.44 μg/l; d = 0.4. A significant exposure effect was found for the low chlorinated PCBs 28 (0.28 ± 0.25 μg/l; d = 1.5 and 101 (0.07 ± 0.09 μg/l; d = 0.7. Although no neuropsychological effects exceeded the adjusted significance level, estimation statistics showed elevated effect sizes for several variables. The objectively exposed subgroup showed a trend towards increased subjective attentional and emotional complaints (tiredness and slowing of practical activities, emotional state as well as attenuated attentional performance (response shifting and alertness in a cued reaction task. Conclusion Chronic inhalation of low chlorinated PCBs that involved elevated blood levels was associated with a subtle attenuation of emotional well

  6. Injury to the blood-testis barrier after low-dose-rate chronic radiation exposure in mice

    International Nuclear Information System (INIS)

    Exposure to ionising radiation induces male infertility, accompanied by increasing permeability of the blood-testis barrier. However, the effect on male fertility by low-dose-rate chronic radiation has not been investigated. In this study, the effects of low-dose-rate chronic radiation on male mice were investigated by measuring the levels of tight-junction-associated proteins (ZO-1 and occludin-1), Niemann-Pick disease type 2 protein (NPC-2) and anti-sperm antibody (AsAb) in serum. BALB/c mice were exposed to low-dose-rate radiation (3.49 mGy h-1) for total exposures of 0.02 (6 h), 0.17 (2 d) and 1.7 Gy (21 d). Based on histological examination, the diameter and epithelial depth of seminiferous tubules were significantly decreased in 1.7-Gy-irradiated mice. Compared with those of the non-irradiated group, 1.7-Gy-irradiated mice showed significantly decreased ZO-1, occludin-1 and NPC-2 protein levels, accompanied with increased serum AsAb levels. These results suggest potential blood-testis barrier injury and immune infertility in male mice exposed to low-dose-rate chronic radiation. (authors)

  7. Continuing Exposure to Low-Dose Nonylphenol Aggravates Adenine-Induced Chronic Renal Dysfunction and Role of Rosuvastatin Therapy

    Directory of Open Access Journals (Sweden)

    Yen Chia-Hung

    2012-07-01

    Full Text Available Abstract Background Nonylphenol (NP, an environmental organic compound, has been demonstrated to enhance reactive-oxygen species (ROS synthesis. Chronic exposure to low-dose adenine (AD has been reported to induce chronic kidney disease (CKD. Methods In this study, we tested the hypothesis that chronic exposure to NP will aggravate AD-induced CKD through increasing generations of inflammation, ROS, and apoptosis that could be attenuated by rosuvastatin. Fifty male Wistar rats were equally divided into group 1 (control, group 2 (AD in fodder at a concentration of 0.25%, group 3 (NP: 2 mg/kg/day, group 4 (combined AD & NP, and group 5 (AD-NP + rosuvastatin: 20 mg/kg/day. Treatment was continued for 24 weeks for all animals before being sacrificed. Results By the end of 24 weeks, serum blood urea nitrogen (BUN and creatinine levels were increased in group 4 than in groups 1–3, but significantly reduced in group 5 as compared with group 4 (all p  Conclusion NP worsened AD-induced CKD that could be reversed by rosuvastatin therapy.

  8. Chronic occupational exposure to arsenic induces carcinogenic gene signaling networks and neoplastic transformation in human lung epithelial cells

    International Nuclear Information System (INIS)

    Chronic arsenic exposure remains a human health risk; however a clear mode of action to understand gene signaling-driven arsenic carcinogenesis is currently lacking. This study chronically exposed human lung epithelial BEAS-2B cells to low-dose arsenic trioxide to elucidate cancer promoting gene signaling networks associated with arsenic-transformed (B-As) cells. Following a 6 month exposure, exposed cells were assessed for enhanced cell proliferation, colony formation, invasion ability and in vivo tumor formation compared to control cell lines. Collected mRNA was subjected to whole genome expression microarray profiling followed by in silico Ingenuity Pathway Analysis (IPA) to identify lung carcinogenesis modes of action. B-As cells displayed significant increases in proliferation, colony formation and invasion ability compared to BEAS-2B cells. B-As injections into nude mice resulted in development of primary and secondary metastatic tumors. Arsenic exposure resulted in widespread up-regulation of genes associated with mitochondrial metabolism and increased reactive oxygen species protection suggesting mitochondrial dysfunction. Carcinogenic initiation via reactive oxygen species and epigenetic mechanisms was further supported by altered DNA repair, histone, and ROS-sensitive signaling. NF-κB, MAPK and NCOR1 signaling disrupted PPARα/δ-mediated lipid homeostasis. A ‘pro-cancer’ gene signaling network identified increased survival, proliferation, inflammation, metabolism, anti-apoptosis and mobility signaling. IPA-ranked signaling networks identified altered p21, EF1α, Akt, MAPK, and NF-κB signaling networks promoting genetic disorder, altered cell cycle, cancer and changes in nucleic acid and energy metabolism. In conclusion, transformed B-As cells with their whole genome expression profile provide an in vitro arsenic model for future lung cancer signaling research and data for chronic arsenic exposure risk assessment. Highlights: ► Chronic As2O3

  9. Chronic occupational exposure to arsenic induces carcinogenic gene signaling networks and neoplastic transformation in human lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Stueckle, Todd A., E-mail: tstueckle@hsc.wvu.edu [Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506 (United States); Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505 (United States); Lu, Yongju, E-mail: yongju6@hotmail.com [Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506 (United States); Davis, Mary E., E-mail: mdavis@wvu.edu [Department of Physiology, West Virginia University, Morgantown, WV 26506 (United States); Wang, Liying, E-mail: lmw6@cdc.gov [Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505 (United States); Jiang, Bing-Hua, E-mail: bhjiang@jefferson.edu [Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107 (United States); Holaskova, Ida, E-mail: iholaskova@hsc.wvu.edu [Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV 26506 (United States); Schafer, Rosana, E-mail: rschafer@hsc.wvu.edu [Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV 26506 (United States); Barnett, John B., E-mail: jbarnett@hsc.wvu.edu [Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV 26506 (United States); Rojanasakul, Yon, E-mail: yrojan@hsc.wvu.edu [Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506 (United States)

    2012-06-01

    Chronic arsenic exposure remains a human health risk; however a clear mode of action to understand gene signaling-driven arsenic carcinogenesis is currently lacking. This study chronically exposed human lung epithelial BEAS-2B cells to low-dose arsenic trioxide to elucidate cancer promoting gene signaling networks associated with arsenic-transformed (B-As) cells. Following a 6 month exposure, exposed cells were assessed for enhanced cell proliferation, colony formation, invasion ability and in vivo tumor formation compared to control cell lines. Collected mRNA was subjected to whole genome expression microarray profiling followed by in silico Ingenuity Pathway Analysis (IPA) to identify lung carcinogenesis modes of action. B-As cells displayed significant increases in proliferation, colony formation and invasion ability compared to BEAS-2B cells. B-As injections into nude mice resulted in development of primary and secondary metastatic tumors. Arsenic exposure resulted in widespread up-regulation of genes associated with mitochondrial metabolism and increased reactive oxygen species protection suggesting mitochondrial dysfunction. Carcinogenic initiation via reactive oxygen species and epigenetic mechanisms was further supported by altered DNA repair, histone, and ROS-sensitive signaling. NF-κB, MAPK and NCOR1 signaling disrupted PPARα/δ-mediated lipid homeostasis. A ‘pro-cancer’ gene signaling network identified increased survival, proliferation, inflammation, metabolism, anti-apoptosis and mobility signaling. IPA-ranked signaling networks identified altered p21, EF1α, Akt, MAPK, and NF-κB signaling networks promoting genetic disorder, altered cell cycle, cancer and changes in nucleic acid and energy metabolism. In conclusion, transformed B-As cells with their whole genome expression profile provide an in vitro arsenic model for future lung cancer signaling research and data for chronic arsenic exposure risk assessment. Highlights: ► Chronic As{sub 2}O

  10. Exposure to daily ambient particulate polycyclic aromatic hydrocarbons and cough occurrence in adult chronic cough patients: A longitudinal study

    Science.gov (United States)

    Anyenda, Enoch Olando; Higashi, Tomomi; Kambayashi, Yasuhiro; Thao, Nguyen Thi Thu; Michigami, Yoshimasa; Fujimura, Masaki; Hara, Johsuke; Tsujiguchi, Hiromasa; Kitaoka, Masami; Asakura, Hiroki; Hori, Daisuke; Yamada, Yohei; Hayashi, Koichiro; Hayakawa, Kazuichi; Nakamura, Hiroyuki

    2016-09-01

    The specific components of airborne particulates responsible for adverse health effects have not been conclusively identified. We conducted a longitudinal study on 88 adult patients with chronic cough to evaluate whether exposure to daily ambient levels of particulate polycyclic aromatic hydrocarbons (PAH) has relationship with cough occurrence. Study participants were recruited at Kanazawa University Hospital, Japan and were physician-diagnosed to at least have asthma, cough variant asthma and/or atopic cough during 4th January to 30th June 2011. Daily cough symptoms were collected by use of cough diaries and simultaneously, particulate PAH content in daily total suspended particles collected on glass fiber filters were determined by high performance liquid chromatography coupled with fluorescence detector. Population averaged estimates of association between PAH exposure and cough occurrence for entire patients and subgroups according to doctor's diagnosis were performed using generalized estimating equations. Selected adjusted odds ratios for cough occurrence were 1.088 (95% confidence interval (CI): 1.031, 1.147); 1.209 (95% CI: 1.060, 1.379) per 1 ng/m3 increase for 2-day lag and 6-day moving average PAH exposure respectively. Likewise, 5 ring PAH had higher odds in comparison to 4 ring PAH. On the basis of doctor's diagnosis, non-asthma group had slightly higher odds ratio 1.127 (95% CI: 1.033, 1.228) per 1 ng/m3 increase in 2-day lag PAH exposure. Our findings suggest that ambient PAH exposure is associated with cough occurrence in adult chronic cough patients. The association may be stronger in non-asthma patients and even at low levels although there is need for further study with a larger sample size of respective diagnosis and inclusion of co-pollutants.

  11. Chronic exposure to low benzo[a]pyrene level causes neurodegenerative disease-like syndromes in zebrafish (Danio rerio).

    Science.gov (United States)

    Gao, Dongxu; Wu, Meifang; Wang, Chonggang; Wang, Yuanchuan; Zuo, Zhenghong

    2015-10-01

    Previous epidemiological and animal studies report that exposure to environmental pollutant exposure links to neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease. Benzo[a]pyrene (BaP), a neurotoxic polycyclic aromatic hydrocarbon, has been increasingly released into the environment during recent decades. So far, the role of BaP on the development of neurodegenerative diseases remaind unclear. This study aimed to determine whether chronic exposure to low dose BaP would cause neurodegenerative disease-like syndromes in zebrafish (Danio rerio). We exposed zebrafish, from early embryogenesis to adults, to environmentally relevant concentrations of BaP for 230 days. Our results indicated that BaP decreased the brain weight to body weight ratio, locomotor activity and cognitive ability; induced the loss of dopaminergic neurons; and resulted in neurodegeneration. In addition, obvious cell apoptosis in the brain was found. Furthermore, the neurotransmitter levels of dopamine and 3,4-dihydroxyphenylacetic acid, the mRNA levels of the genes encoding dopamine transporter, Parkinson protein 7, phosphatase and tensin-induced putative kinase 1, ubiquitin carboxy-terminal hydrolase L1, leucine-rich repeat serine/threonine kinase 2, amyloid precursor protein b, presenilin 1 and presenilin 2 were significantly down-regulated by BaP exposure. These findings suggest that chronic exposure to low dose BaP could cause the behavioral, neuropathological, neurochemical, and genetic features of neurodegenerative diseases. This study provides clues that BaP may constitute an important environmental risk factor for neurodegenerative diseases in humans. PMID:26349946

  12. Using expression profiling to understand the effects of chronic cadmium exposure on MCF-7 breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Zelmina Lubovac-Pilav

    Full Text Available Cadmium is a metalloestrogen known to activate the estrogen receptor and promote breast cancer cell growth. Previous studies have implicated cadmium in the development of more malignant tumors; however the molecular mechanisms behind this cadmium-induced malignancy remain elusive. Using clonal cell lines derived from exposing breast cancer cells to cadmium for over 6 months (MCF-7-Cd4, -Cd6, -Cd7, -Cd8 and -Cd12, this study aims to identify gene expression signatures associated with chronic cadmium exposure. Our results demonstrate that prolonged cadmium exposure does not merely result in the deregulation of genes but actually leads to a distinctive expression profile. The genes deregulated in cadmium-exposed cells are involved in multiple biological processes (i.e. cell growth, apoptosis, etc. and molecular functions (i.e. cadmium/metal ion binding, transcription factor activity, etc.. Hierarchical clustering demonstrates that the five clonal cadmium cell lines share a common gene expression signature of breast cancer associated genes, clearly differentiating control cells from cadmium exposed cells. The results presented in this study offer insights into the cellular and molecular impacts of cadmium on breast cancer and emphasize the importance of studying chronic cadmium exposure as one possible mechanism of promoting breast cancer progression.

  13. Risk Analysis of Acute Or Chronic Exposure to Arsenic of the Inhabitants in a District of Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    Cristina Vázquez

    2016-09-01

    Full Text Available The arsenic occurrence in the water constitutes a serious world health concern due to its toxicity. Depending on the intensity and duration of exposure, this element can be acutely lethal or may have a wide range of health effects in humans and animals. In Argentina, the origin of arsenic is mainly natural, and related to different geological processes. The Argentinean concern about arsenic and its influence on human health dates back to the previous century. The disease ascribed to arsenic contamination was called ‘chronic regional endemic hydroarsenism’. It is produced by the consumption of water with high levels of this element. In our study, we focused in La Matanza district, a very populated site in the Buenos Aires Province. An increasing concern of the inhabitants of the area regarding health problems was detected. In order to establish a full view of arsenic exposure in the area, several matrices and targets were analyzed. As matrices, water and soil samples were analyzed. As targets, canine and human hair was studied. The aim of this study was to investigate acute and chronically exposure to arsenic of La Matanza inhabitants.

  14. Chronic copper exposure and fatty acid composition of the amphipod Dikerogammarus villosus: Results from a field study

    International Nuclear Information System (INIS)

    Field study allows assessment of long-term effects on fatty acid (FA) composition of organisms under chronic exposure to metals. One expected effect of copper is peroxidation of lipids and essentially polyunsaturated fatty acids (PUFA). FA analysis was established for the amphipod Dikerogammarus villosus subjected to different degrees of copper exposure (4-40 μg Cu L-1). A previous study in our team showed that this species regulates its body Cu concentration (106-135 mg Cu kg-1 dry weight). Despite the high capacity of bioaccumulation, the absence of a correlation between copper concentration in D. villosus and water prevents its use as bioindicator of copper pollution. Both sexes from the most polluted site showed the lowest total FA content, but the highest PUFA percent, mainly of the long-chained variety (C20-C22). Mechanisms leading to the prevention of lipid peroxidation in this species were discussed (metallothioneins and intracellular granules) and proposed with support from literature data. - Under chronic copper exposure, Dikerogammarus villosus loses in total fatty acids content but increases its essential ω3 and ω6 PUFA percent

  15. Chronic copper exposure and fatty acid composition of the amphipod Dikerogammarus villosus: Results from a field study

    Energy Technology Data Exchange (ETDEWEB)

    Maazouzi, Chafik [Universite de Metz, Laboratoire Interactions Ecotoxicologie Biodiversite Ecosystemes (LIEBE), CNRS UMR 7146, Avenue General Delestraint, 57070 Metz (France)], E-mail: maazouzi@univ-metz.fr; Masson, Gerard [Universite de Metz, Laboratoire Interactions Ecotoxicologie Biodiversite Ecosystemes (LIEBE), CNRS UMR 7146, Avenue General Delestraint, 57070 Metz (France)], E-mail: masson1@univ-metz.fr; Izquierdo, Maria Soledad [Grupo de Investigacion en Acuicultura, ULPGC and ICCM, P.O. Box 56, 35200 Telde, Las Palmas de Gran Canaria (Spain)], E-mail: mizquierdo@dbio.ulpgc.es; Pihan, Jean-Claude [Universite de Metz, Laboratoire Interactions Ecotoxicologie Biodiversite Ecosystemes (LIEBE), CNRS UMR 7146, Avenue General Delestraint, 57070 Metz (France)], E-mail: pihan@univ-metz.fr

    2008-11-15

    Field study allows assessment of long-term effects on fatty acid (FA) composition of organisms under chronic exposure to metals. One expected effect of copper is peroxidation of lipids and essentially polyunsaturated fatty acids (PUFA). FA analysis was established for the amphipod Dikerogammarus villosus subjected to different degrees of copper exposure (4-40 {mu}g Cu L{sup -1}). A previous study in our team showed that this species regulates its body Cu concentration (106-135 mg Cu kg{sup -1} dry weight). Despite the high capacity of bioaccumulation, the absence of a correlation between copper concentration in D. villosus and water prevents its use as bioindicator of copper pollution. Both sexes from the most polluted site showed the lowest total FA content, but the highest PUFA percent, mainly of the long-chained variety (C20-C22). Mechanisms leading to the prevention of lipid peroxidation in this species were discussed (metallothioneins and intracellular granules) and proposed with support from literature data. - Under chronic copper exposure, Dikerogammarus villosus loses in total fatty acids content but increases its essential {omega}3 and {omega}6 PUFA percent.

  16. Impact of chronic cadmium exposure at environmental dose on escape behaviour in sea bass (Dicentrarchus labrax L.; Teleostei, Moronidae)

    International Nuclear Information System (INIS)

    The effect of chronic exposure to a low concentration (0.5 μg l-1) of cadmium ions was investigated on escape behaviour of sea bass, Dicentrarchus labrax, using video analysis. Observations were also performed on the microanatomy of lateral system neuromasts. When fish were exposed for 4 h per day over 8 days to the cadmium ions, most of both types of neuromasts observed remained intact. However, some of them presented damaged sensory maculae. Whereas before cadmium exposure, fish responded positively to nearly all the lateral system stimulations, after exposure they decreased by about 10% their positive responses to stimulations. From the 15th day after the beginning of cadmium exposure, neuromasts presented progressively less damage, cadmium accumulation in gills and scales decreased significantly and fish escape behaviour had recovered. This study presents a new concept in ecotoxicology: using behavioural change to reveal the effects of pollution levels, scarcely detectable by currently used techniques (physiological responses). - Cadmium exposure involved a significant bioaccumulation in fish scales, slight damage to the lateral line system and a significant decrease in fish escape behaviour

  17. Chronic pain relief after the exposure of nitrous oxide during dental treatment: longitudinal retrospective study

    Directory of Open Access Journals (Sweden)

    Francisco Moreira Mattos Júnior

    2015-07-01

    Full Text Available The objective was to investigate the effect of nitrous/oxygen in chronic pain. Seventy-seven chronic pain patients referred to dental treatment with conscious sedation with nitrous oxide/oxygen had their records included in this research. Data were collected regarding the location and intensity of pain by the visual analogue scale before and after the treatment. Statistical analysis was performed comparing pre- and post-treatment findings. It was observed a remarkable decrease in the prevalence of pain in this sample (only 18 patients still had chronic pain, p < 0.001 and in its intensity (p < 0.001. Patients that needed fewer sessions received higher proportions of nitrous oxide/oxygen. Nitrous oxide may be a tool to be used in the treatment of chronic pain, and future prospective studies are necessary to understand the underlying mechanisms and the effect of nitrous oxide/oxygen in patients according to the pain diagnosis and other characteristics.

  18. Pulmonary sensitivity to ozone exposure in sedentary versus chronically trained, female rats

    Data.gov (United States)

    U.S. Environmental Protection Agency — Pulmonary effects to ozone with rats that have chronically exercised or have been continuously sedentary. Also includes body composition of both groups throughout...

  19. Persistent modification of Na{sub v}1.9 following chronic exposure to insecticides and pyridostigmine bromide

    Energy Technology Data Exchange (ETDEWEB)

    Nutter, Thomas J., E-mail: tnutter@dental.ufl.edu; Cooper, Brian Y., E-mail: bcooper@dental.ufl.edu

    2014-06-15

    Many veterans of the 1991 Gulf War (GW) returned from that conflict with a widespread chronic pain affecting deep tissues. Recently, we have shown that a 60 day exposure to the insecticides permethrin, chlorpyrifos, and pyridostigmine bromide (NTPB) had little influence on nociceptor action potential forming Na{sub v}1.8, but increased K{sub v}7 mediated inhibitory currents 8 weeks after treatment. Using the same exposure regimen, we used whole cell patch methods to examine whether the influences of NTPB could be observed on Na{sub v}1.9 expressed in muscle and vascular nociceptors. During a 60 day exposure to NTPB, rats exhibited lowered muscle pain thresholds and increased rest periods, but these measures subsequently returned to normal levels. Eight and 12 weeks after treatments ceased, DRG neurons were excised from the sensory ganglia. Whole cell patch studies revealed little change in voltage dependent activation and deactivation of Na{sub v}1.9, but significant increases in the amplitude of Na{sub v}1.9 were observed 8 weeks after exposure. Cellular studies, at the 8 week delay, revealed that NTPB also significantly prolonged action potential duration and afterhyperpolarization (22 °C). Acute application of permethrin (10 μM) also increased the amplitude of Na{sub v}1.9 in skin, muscle and vascular nociceptors. In conclusion, chronic exposure to Gulf War agents produced long term changes in the amplitude of Na{sub v}1.9 expressed in muscle and vascular nociceptors. The reported increases in K{sub v}7 amplitude may have been an adaptive response to increased Na{sub v}1.9, and effectively suppressed behavioral pain measures in the post treatment period. Factors that alter the balance between Na{sub v}1.9 and K{sub v}7 could release spontaneous discharge and produce chronic deep tissue pain. - Highlights: • Rats were treated 60 days with permethrin, chlorpyrifos and pyridostigmine bromide. • 8 weeks after treatments, Nav1.9 activation and deactivation were

  20. MAPK pathway activation by chronic lead-exposure increases vascular reactivity through oxidative stress/cyclooxygenase-2-dependent pathways

    Energy Technology Data Exchange (ETDEWEB)

    Simões, Maylla Ronacher, E-mail: yllars@hotmail.com [Dept. of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES CEP 29040-091 (Brazil); Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain); Aguado, Andrea [Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain); Fiorim, Jonaína; Silveira, Edna Aparecida; Azevedo, Bruna Fernandes; Toscano, Cindy Medice [Dept. of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES CEP 29040-091 (Brazil); Zhenyukh, Olha; Briones, Ana María [Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain); Alonso, María Jesús [Dept. of Biochemistry, Physiology and Molecular Genetics, Universidad Rey Juan Carlos, Alcorcón (Spain); Vassallo, Dalton Valentim [Dept. of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES CEP 29040-091 (Brazil); Health Science Center of Vitória-EMESCAM, Vitória, ES CEP 29045-402 (Brazil); Salaices, Mercedes, E-mail: mercedes.salaices@uam.es [Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain)

    2015-03-01

    Chronic exposure to low lead concentration produces hypertension; however, the underlying mechanisms remain unclear. We analyzed the role of oxidative stress, cyclooxygenase-2-dependent pathways and MAPK in the vascular alterations induced by chronic lead exposure. Aortas from lead-treated Wistar rats (1st dose: 10 μg/100 g; subsequent doses: 0.125 μg/100 g, intramuscular, 30 days) and cultured aortic vascular smooth muscle cells (VSMCs) from Sprague Dawley rats stimulated with lead (20 μg/dL) were used. Lead blood levels of treated rats attained 21.7 ± 2.38 μg/dL. Lead exposure increased systolic blood pressure and aortic ring contractile response to phenylephrine, reduced acetylcholine-induced relaxation and did not affect sodium nitroprusside relaxation. Endothelium removal and L-NAME left-shifted the response to phenylephrine more in untreated than in lead-treated rats. Apocynin and indomethacin decreased more the response to phenylephrine in treated than in untreated rats. Aortic protein expression of gp91(phox), Cu/Zn-SOD, Mn-SOD and COX-2 increased after lead exposure. In cultured VSMCs lead 1) increased superoxide anion production, NADPH oxidase activity and gene and/or protein levels of NOX-1, NOX-4, Mn-SOD, EC-SOD and COX-2 and 2) activated ERK1/2 and p38 MAPK. Both antioxidants and COX-2 inhibitors normalized superoxide anion production, NADPH oxidase activity and mRNA levels of NOX-1, NOX-4 and COX-2. Blockade of the ERK1/2 and p38 signaling pathways abolished lead-induced NOX-1, NOX-4 and COX-2 expression. Results show that lead activation of the MAPK signaling pathways activates inflammatory proteins such as NADPH oxidase and COX-2, suggesting a reciprocal interplay and contribution to vascular dysfunction as an underlying mechanisms for lead-induced hypertension. - Highlights: • Lead-exposure increases oxidative stress, COX-2 expression and vascular reactivity. • Lead exposure activates MAPK signaling pathway. • ROS and COX-2 activation by

  1. MAPK pathway activation by chronic lead-exposure increases vascular reactivity through oxidative stress/cyclooxygenase-2-dependent pathways

    International Nuclear Information System (INIS)

    Chronic exposure to low lead concentration produces hypertension; however, the underlying mechanisms remain unclear. We analyzed the role of oxidative stress, cyclooxygenase-2-dependent pathways and MAPK in the vascular alterations induced by chronic lead exposure. Aortas from lead-treated Wistar rats (1st dose: 10 μg/100 g; subsequent doses: 0.125 μg/100 g, intramuscular, 30 days) and cultured aortic vascular smooth muscle cells (VSMCs) from Sprague Dawley rats stimulated with lead (20 μg/dL) were used. Lead blood levels of treated rats attained 21.7 ± 2.38 μg/dL. Lead exposure increased systolic blood pressure and aortic ring contractile response to phenylephrine, reduced acetylcholine-induced relaxation and did not affect sodium nitroprusside relaxation. Endothelium removal and L-NAME left-shifted the response to phenylephrine more in untreated than in lead-treated rats. Apocynin and indomethacin decreased more the response to phenylephrine in treated than in untreated rats. Aortic protein expression of gp91(phox), Cu/Zn-SOD, Mn-SOD and COX-2 increased after lead exposure. In cultured VSMCs lead 1) increased superoxide anion production, NADPH oxidase activity and gene and/or protein levels of NOX-1, NOX-4, Mn-SOD, EC-SOD and COX-2 and 2) activated ERK1/2 and p38 MAPK. Both antioxidants and COX-2 inhibitors normalized superoxide anion production, NADPH oxidase activity and mRNA levels of NOX-1, NOX-4 and COX-2. Blockade of the ERK1/2 and p38 signaling pathways abolished lead-induced NOX-1, NOX-4 and COX-2 expression. Results show that lead activation of the MAPK signaling pathways activates inflammatory proteins such as NADPH oxidase and COX-2, suggesting a reciprocal interplay and contribution to vascular dysfunction as an underlying mechanisms for lead-induced hypertension. - Highlights: • Lead-exposure increases oxidative stress, COX-2 expression and vascular reactivity. • Lead exposure activates MAPK signaling pathway. • ROS and COX-2 activation by

  2. Chronic Exposure to Beta-Blockers Attenuates Inflammation and Mucin Content in a Murine Asthma Model

    OpenAIRE

    Nguyen, Long P.; Omoluabi, Ozozoma; Parra, Sergio; Frieske, Joanna M.; Clement, Cecilia; Ammar-Aouchiche, Zoulikha; Ho, Samuel B.; Ehre, Camille; Kesimer, Mehmet; Knoll, Brian J.; Tuvim, Michael J; Dickey, Burton F.; Bond, Richard A.

    2007-01-01

    Single-dose administration of beta-adrenoceptor agonists produces bronchodilation and inhibits airway hyperresponsiveness (AHR), and is the standard treatment for the acute relief of asthma. However, chronic repetitive administration of beta-adrenoceptor agonists may increase AHR, airway inflammation, and risk of death. Based upon the paradigm shift that occurred with the use of beta-blockers in congestive heart failure, we previously determined that chronic administration of beta-blockers de...

  3. Chronic exposure of ecosystems and public to elements in trace contributions

    International Nuclear Information System (INIS)

    The needs in radiation protection come towards the question of chronic contaminations by trace elements or radioactive compounds. The chronicity induces to take into account a whole of redistribution mechanisms more important than the only ways of the most direct transfer. In the case of environment, that is going to become one of the way of public contamination is a target to protect, the important work is to link the contamination situation to eventual consequences on the ecosystems situation. (N.C.)

  4. Chronic exposure to perfluorinated compounds: Impact on airway hyperresponsiveness and inflammation

    OpenAIRE

    Ryu, Min H.; Jha, Aruni; Ojo, Oluwaseun O.; Mahood, Thomas H.; Basu, Sujata; Detillieux, Karen A.; Nikoobakht, Neda; Wong, Charles S.; Loewen, Mark; Allan B Becker; Halayko, Andrew J.

    2014-01-01

    Emerging epidemiological evidence reveals a link between lung disease and exposure to indoor pollutants such as perfluorinated compounds (PFCs). PFC exposure during critical developmental stages may increase asthma susceptibility. Thus, in a murine model, we tested the hypothesis that early life and continued exposure to two ubiquitous household PFCs, perfluorooctanoic acid (PFOA) and perflurooctanesulfonic acid (PFOS), can induce lung dysfunction that exacerbates allergen-induced airway hype...

  5. INDUCTION OF CHRONIC KIDNEY FAILURE IN A LONG-TERM PERITONEAL EXPOSURE MODEL IN THE RAT: EFFECTS ON FUNCTIONAL AND STRUCTURAL PERITONEAL ALTERATIONS

    NARCIS (Netherlands)

    F. Vrtovsnik; A. Coester; D. Lopes-Barreto; D.R. de Waart; A. van der Wal; D.G. Struijk; R. Krediet; M. Zweers

    2010-01-01

    Background: A long-term peritoneal exposure model has been developed in Wistar rats. Chronic daily exposure to 3.86% glucose based, lactate buffered, conventional dialysis solutions is possible for up to 20 weeks and induces morphological abnormalities similar to those in long-term peritoneal dialys

  6. Concomitant stress potentiates the preference for, and consumption of, ethanol induced by chronic pre-exposure to ethanol

    Directory of Open Access Journals (Sweden)

    G. Morais-Silva

    2016-01-01

    Full Text Available Ethanol abuse is linked to several acute and chronic injuries that can lead to health problems. Ethanol addiction is one of the most severe diseases linked to the abuse of this drug. Symptoms of ethanol addiction include compulsive substance intake and withdrawal syndrome. Stress exposure has an important role in addictive behavior for many drugs of abuse (including ethanol, but the consequences of stress and ethanol in the organism when these factors are concomitant results in a complex interaction. We investigated the effects of concomitant, chronic administration of ethanol and stress exposure on the withdrawal and consumption of, as well as the preference for, ethanol in mice. Male Swiss mice (30–35 g, 8-10 per group were exposed to an ethanol liquid diet as the only source of food for 15 days. In the final 5 days, they were exposed to forced swimming stress. Twelve hours after removal of the ethanol liquid diet, animals were evaluated for ethanol withdrawal by measuring anxiety-related behaviors and locomotor activity. Twenty-four hours after evaluation of ethanol withdrawal, they were evaluated for voluntary consumption of ethanol in a “three-bottle choice” paradigm. Mice exposed to chronic consumption of ethanol had decreased locomotor activity during withdrawal. Contrary to our expectations, a concomitant forced swimming stress did not aggravate ethanol withdrawal. Nevertheless, simultaneous ethanol administration and stress exposure increased voluntary consumption of ethanol, mainly solutions containing high concentrations of ethanol. These results showed that stressful situations during ethanol intake may aggravate specific addiction-related behaviors.

  7. The implications of re-analysing radiation-induced leukaemia in atomic bomb survivors: risks for acute and chronic exposures are different

    International Nuclear Information System (INIS)

    Implications of risk estimates, as required for practical radiation protection purposes, were explored through a preliminary re-analysis of leukaemia in the Japanese atomic bomb survivors using a biologically based cancer model. The calculations for the risks posed for contracting leukaemia pointed to important differences between low-dose-rate ('chronic') and high-dose-rate ('acute') exposures. For example, the risks caused by long-term ('chronic') exposures are calculated to be substantially lower than those for 'acute' exposures. In view of these model predictions the results of epidemiological studies are discussed. (author)

  8. Impact of water-accommodated fractions of crude oil on Atlantic cod, Gadus morhua following chronic exposure

    International Nuclear Information System (INIS)

    This study examined the long-term effects of hydrocarbon exposure on the gonadal development of fish. Mature Atlantic cod (Gadus morhua) were exposed to low concentrations of water accommodated fractions (WAFs) of polycyclic aromatic hydrocarbons (PAHs) in an ambient flowthrough seawater system. Some PAH-exposed cod groups were depurated afterwards for 38 to 287 days. Mortality was rare, and external lesions occurred only in the PAH-exposed groups. The gonado-somatic index revealed that gonadal development was disrupted in both sexes and spawning and spermiation was delayed in the 33 depurated PAH-groups. The findings indicate that chronic exposure to WAFs in the water column may have an adverse effect on reproduction in Atlantic cod.

  9. Effects of chronic produced water exposure on the expression of some immune-related genes of juvenile Atlantic cod

    International Nuclear Information System (INIS)

    This study assessed the impacts of exposure to processed water produced by offshore oil operators on immune-related genes of juvenile Atlantic cod exposed to processed water for a period of 22 weeks. The study investigated the influence of processed water concentrations on growth parameters; food consumption; plasma cortisol; respiratory burst activity (RB); and mRNA expression. The study showed that the RB of circulating leukocytes was significantly elevated. Significant up-regulation of the mRNA expression of microglobulin, immunoglobulin light chain, and interleukins was observed in some fish. The down-regulation of the interferon stimulated gene was also observed. The study indicated that chronic exposure to significant amounts of processed water causes modulations of the immune system of juvenile Atlantic cod.

  10. Uranium: biokinetics and toxicity

    International Nuclear Information System (INIS)

    This report was achieved as a part of a collaboration with the Fuel Cycle Direction. Its aim was to give the state of the art about: the behaviour of uranium in the human organism (biokinetics) after ingestion, its toxicity (mainly renal) and the current regulation about its incorporation. Both in the upstream and in the downstream of the fuel cycle, uranium remains, quantitatively, the first element in the cycle which is, at the present time, temporarily disposed or recycled. Such a considerable quantity of uranium sets the problem of its risk on the health. In the long term, the biosphere may be affected and consequently the public may ingest water or food contaminated with uranium. In this way, radiological and chemical toxicity risk may be activated. This report emphasizes: the necessity of confirming some experimental and epidemiological biokinetic data used or not in the ICRP models. Unsolved questions remain about the gastrointestinal absorption according to chemical form (valency state, mixtures...), mass and individual variations (age, disease) further a chronic ingestion of uranium. It is well established that uranium is mainly deposited in the skeleton and the kidney. But the skeleton kinetics following a chronic ingestion and especially in some diseases has to be more elucidated; the necessity of taking into account uranium at first as a chemical toxic, essentially in the kidney and determining the threshold of functional lesion. In this way, it is important to look for some specific markers; the problem of not considering chemical toxicity of uranium in the texts regulating its incorporation

  11. In vivo chronic intermittent ethanol exposure reverses the polarity of synaptic plasticity in the nucleus accumbens shell.

    Science.gov (United States)

    Jeanes, Zachary M; Buske, Tavanna R; Morrisett, Richard A

    2011-01-01

    Glutamatergic synaptic plasticity in the nucleus accumbens (NAc) is implicated in response to sensitization to psychomotor-stimulating agents, yet ethanol effects here are undefined. We studied the acute in vitro and in vivo effects of ethanol in medium spiny neurons from the shell NAc subregion of slices of C57BL/6 mice by using whole-cell voltage-clamp recordings of α-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA) excitatory postsynaptic current (EPSCs). Synaptic conditioning (low-frequency stimulation with concurrent postsynaptic depolarization) reliably depressed AMPA EPSCs by nearly 30%; this accumbal long-term depression (LTD) was blocked by a nonselective N-methyl-D-aspartate (NMDA) receptor antagonist (DL-2-amino-5-phosphonovaleric acid) and a selective NMDA receptor 2B antagonist [R-(R*,S*)-α-(4-hydroxyphenyl)-β-methyl-4-(phenylmethyl)-1-piperidine propanol]. Acute ethanol exposure inhibited the depression of AMPA EPSCs differentially with increasing concentrations, but this inhibitory action of ethanol was occluded by a D1-selective dopamine receptor agonist. Ethanol dependence was elicited in C57BL/6 mice by two separate 4-day bouts of chronic intermittent ethanol (CIE) vapor exposure. When assessed 24 h after a single bout of in vivo CIE vapor exposure, NAc LTD was absent, and instead NMDA receptor-dependent synaptic potentiation [long-term potentiation (LTP)] was reliably observed. It is noteworthy that both LTP and LTD were completely absent after an extended withdrawal (72 h) after a single 3-day CIE vapor bout. These observations demonstrate that 1) accumbal synaptic depression is mediated by NR2B receptors, 2) accumbal synaptic depression is highly sensitive to both acute and chronic ethanol exposure, and 3) alterations in this synaptic process may constitute a neural adaptation that contributes to the induction and/or expression of ethanol dependence. PMID:20947635

  12. Chronic Exposure to Androgenic-Anabolic Steroids Exacerbates Axonal Injury and Microgliosis in the CHIMERA Mouse Model of Repetitive Concussion.

    Science.gov (United States)

    Namjoshi, Dhananjay R; Cheng, Wai Hang; Carr, Michael; Martens, Kris M; Zareyan, Shahab; Wilkinson, Anna; McInnes, Kurt A; Cripton, Peter A; Wellington, Cheryl L

    2016-01-01

    Concussion is a serious health concern. Concussion in athletes is of particular interest with respect to the relationship of concussion exposure to risk of chronic traumatic encephalopathy (CTE), a neurodegenerative condition associated with altered cognitive and psychiatric functions and profound tauopathy. However, much remains to be learned about factors other than cumulative exposure that could influence concussion pathogenesis. Approximately 20% of CTE cases report a history of substance use including androgenic-anabolic steroids (AAS). How acute, chronic, or historical AAS use may affect the vulnerability of the brain to concussion is unknown. We therefore tested whether antecedent AAS exposure in young, male C57Bl/6 mice affects acute behavioral and neuropathological responses to mild traumatic brain injury (TBI) induced with the CHIMERA (Closed Head Impact Model of Engineered Rotational Acceleration) platform. Male C57Bl/6 mice received either vehicle or a cocktail of three AAS (testosterone, nandrolone and 17α-methyltestosterone) from 8-16 weeks of age. At the end of the 7th week of treatment, mice underwent two closed-head TBI or sham procedures spaced 24 h apart using CHIMERA. Post-repetitive TBI (rTBI) behavior was assessed for 7 d followed by tissue collection. AAS treatment induced the expected physiological changes including increased body weight, testicular atrophy, aggression and downregulation of brain 5-HT1B receptor expression. rTBI induced behavioral deficits, widespread axonal injury and white matter microgliosis. While AAS treatment did not worsen post-rTBI behavioral changes, AAS-treated mice exhibited significantly exacerbated axonal injury and microgliosis, indicating that AAS exposure can alter neuronal and innate immune responses to concussive TBI. PMID:26784694

  13. The French cohort of uranium miners: Analysis of lung cancer risk linked to radon exposure in a population exposed to relatively low concentration over a long duration

    International Nuclear Information System (INIS)

    In France, about 5,000 miners have been employed in uranium mining industry since 1946. Most of these miners have experienced relatively low annual exposures in comparison to other cohorts of miners. Consequently, the hypothesis to be tested in our study was the potential risk of cancer in a relatively low exposed population, characterised by a long period of underground work. A first analysis of the ''oldest'' cohort (1,785 miners having worked underground before 1972) has been published in 1993, based on a follow-up to December 1985. Recently, this follow-up has been extended up to 1994. Compared to the first analysis, the size of the cohort has increased by 24 %, and the number of lung cancer deaths has increased by about 90 % (from 45 to 85 deaths). Mean cumulated exposure to radon is of 71.5 WML, protracted over more than 15 years. After 1956, radon exposure is lower than 2 WLM/year for 50 % of the miners. The Standardised Mortality Ratio for lung cancer is 1.65, with confidence interval CI95% = [1.3-2.0]. The Excess Relative Risk coefficient for lung cancer with cumulated exposure to radon is ERR/WLM 0.40 % (p = 0.05). This estimate is very similar to the one obtained in the first analysis. The contribution of this population to the estimation of the risk coefficient of lung cancer, in relation to low dose-rates and low cumulative exposure is far from negligible. Enlargement of the French cohort exposed after 1956 is ongoing. Moreover a European joint analysis of cohorts with low levels of exposure rates (French, Czech and German cohorts) will be performed in a near future. (author)

  14. Chronic xerostomia increases esophageal acid exposure and is associated with esophageal injury

    International Nuclear Information System (INIS)

    OBJECTIVES: To assess the effects of chronic xerostomia on parameters of gastroesophageal reflux and esophagitis. DESIGN: Observational study of a cohort of male patients with xerostomia and age-matched control subjects. SETTING: Tertiary-care Veterans Affairs Medical Center. SUBJECTS: Sixteen male patients with chronic xerostomia secondary to radiation for head and neck cancers or medications. Nineteen age-matched male control subjects with comparable alcohol and smoking histories. MEASUREMENTS AND MAIN RESULTS: Esophageal motility was similar in patients with xerostomia and controls. Clearance of acid from the esophagus and 24-hour intraesophageal pH were markedly abnormal in patients with xerostomia. Symptoms and signs of esophagitis were significantly more frequent in subjects with xerostomia. CONCLUSIONS: Chronic xerostomia may predispose to esophageal injury, at least in part, by decreasing the clearance of acid from the esophagus and altering 24-hour intraesophageal pH. Esophageal injury is a previously unreported complication of long-term salivary deficiency

  15. Evaluation of the effect of chronic exposure to 137Cesium on sleep-wake cycle in rats

    International Nuclear Information System (INIS)

    Since the Chernobyl accident, the most significant problem for the population living in the contaminated areas is chronic exposure by ingestion of radionuclides, notably 137Cs, a radioactive isotope of cesium. It can be found in the whole body, including the central nervous system. The present study aimed to assess the effect of 137Cs on the central nervous system and notably on open-field activity and the electroencephalographic pattern. Rats were exposed up to 90 days to drinking water contaminated with 137Cs at a dosage of 400 Bq kg-1, which is similar to that ingested by the population living in contaminated territories. At this level of exposure, no significant effect was observed on open-field activity. On the other hand, at 30 days exposure, 137Cs decreased the number of episodes of wakefulness and slow wave sleep and increased the mean duration of these stages. At 90 days exposure, the power of 0.5-4 Hz band of 137Cs-exposed rats was increased in comparison with controls. These electrophysiological changes may be due to a regional 137Cs accumulation in the brain stem. In conclusion, the neurocognitive effects of 137Cs need further evaluation and central disorders of population living in contaminated territories must be considered

  16. Evaluation of the genotoxic effects of chronic low-dose ionizing radiation exposure on nuclear medicine workers

    International Nuclear Information System (INIS)

    Introduction: Nuclear medicine workers are occupationally exposed to chronic ionizing radiation. It is known that ionizing radiation may have damaging effects on chromosomes. In the present study, we investigated the genotoxic effects of ionizing radiation on nuclear medicine workers. We used two different indicators of genotoxicity methods: sister chromatid exchange (SCE) and micronucleus (MN). Methods: The present research was carried out using 21 nuclear medicine workers (11 females and 10 males) during two periods: during normal working conditions and after a 1-month vacation. The radiation dose varied from 1.20 to 48.56 mSv, which accumulated during the occupational exposure time between two vacations. Peripheral blood samples were taken from each subject for two distinct lymphocyte cultures (SCE and MN) in each period. Results: In nearly all subjects, SCE values increased significantly during radiation exposure compared to the postvacation period (P<.05). Similarly, MN frequencies in most of the subjects increased significantly during radiation exposure compared to the postvacation period (P<.05). Conclusions: This study revealed that both SCE and MN frequencies in most of the subjects were significantly higher during exposure to ionizing radiation than after a 1-month vacation period. However, this genotoxic effect was reversible in most of the subjects.

  17. Chronic exposure to perfluorooctane sulfonate induces behavior defects and neurotoxicity through oxidative damages, in vivo and in vitro.

    Directory of Open Access Journals (Sweden)

    Na Chen

    Full Text Available Perfluorooctane sulfonate (PFOS is an emerging persistent pollutant which shows multiple adverse health effects. However, the neurotoxicity of PFOS and its mechanisms have not been fully elucidated. Using a combination of in vivo and in vitro methods, the present study provides a detailed description of PFOS-induced neurotoxicity. Results showed that the median lethal concentration of PFOS was 2.03 mM in Caenorhabditis elegans for 48 h exposure. 20 µM PFOS caused decrease of locomotor behaviors including forward movement, body bend and head thrash. Additionally, PFOS exposure reduced chemotaxis index of C. elegans, which indicates the decline of chemotaxis learning ability. Using green fluorescent protein (GFP labelled transgenic strains, we found that PFOS caused down-regulated expression of a chemoreceptor gene, gcy-5, in ASE chemosensory neurons, but did not affect cholinergic neurons and dopaminergic neurons. In SH-SY5Y cells, 48 h exposure to 25 µM and 50 µM PFOS induced cell damage, apoptosis and the reactive oxygen species (ROS generation. PFOS caused significant increases of lipid peroxidation and superoxide dismutase activity, but an actual decrease of glutathione peroxidase activity. Furthermore, antioxidant N-acetylcysteine rescued cells from PFOS-induced apoptosis via blocking ROS. Our results demonstrate that chronic exposure to PFOS can cause obvious neurotoxicity and behavior defects. Oxidative damage and anti-oxidative deficit are crucial mechanisms in neurotoxicity of PFOS.

  18. Effect of chronic lead exposure on kidney function in male and female rats: determination of a lead exposure biomarker.

    Science.gov (United States)

    Ghorbe, F; Boujelbene, M; Makni-Ayadi, F; Guermazi, F; Kammoun, A; Murat, J; Croute, F; Soleilhavoup, J P; El-Feki, A

    2001-12-01

    Several cytotoxic chemical pollutants inducing peroxidative damages are liable to induce kidney failure. Among these pollutants we find heavy metals such as: lead, nickel, cadmium, vanadium and mercury. Lead is one of the most dangerous metals because it is widely spread in the environment, and because it may be a source of several nervous diseases. The aim of this study is to provide evidence concerning the effect of this metal on the renal function and to try to determine a storage corner in the organism which serves as an indicator of a lead intoxication. Lead acetate was administered by oral route in the drinking water to adult rats aged three months at the rate of 0.3% (P1) and 0.6% (P2). Reference rats received distilled water to drink under the same conditions. The treatment continued for 15, 30, 45, 60 and 90 days. The creatinemia, uremia, glycemia and creatinuria are determined by colorimetric techniques. Lead concentration in blood as well as the lead content of the tail are determined by atomic absorption after nitroperchloric mineralization at the liquid stage. The results showed an increase of creatinemia on the 30th day of the experiment for both sexes in (P1 and P2). The same happened for ureamia. The increase of these two parameters would indicate a renal deficiency which is confirmed by a decrease of creatinuria and urinary pH observed mainly on and after the 45th day of the experiment. An increase of the renal relative weight was noticed in P1 and P2 on the 30th day of the treatment. The determination of the concentration of lead in the blood shows that this factor increases among treated subjects in a constant way, independently of the dose and the duration of the treatment. Nevertheless, the rate increase of lead in the tail seems to be dose-dependent. In conclusion, lead administered by oral route causes a renal deficiency to the rat without distinction between males and females. In addition, the tail seems to be a reliable exposure biomarker

  19. Acute and chronic effects of pulse exposure of Daphnia magna to dimethoate and pirimicarb.

    Science.gov (United States)

    Andersen, Tobias Henrik; Tjørnhøj, Rikke; Wollenberger, Leah; Slothuus, Tina; Baun, Anders

    2006-05-01

    Short-term (Daphnia magna exposed to pulses of 0.5 to 8 h in duration. During a 21-d postexposure observation period, the following parameters were monitored: Mortality, mobility, day for first offspring, animal size, weight of offspring and adults, and number of offspring produced. In general, animals exposed to a single pulse of dimethoate or pirimicarb regained mobility after 24 to 48 h in clean media. Animals exposed to repeated pulses of dimethoate did not recover mobility during a 48-h postexposure observation period, and mortality was significantly increased. Animals exposed to two pulses of pirimicarb showed less recovery of mobility compared with those exposed to one pulse. Exposure of D. magna to 30 mg/L of dimethoate or 100 microg/L of pirimicarb for 2 to 6 h resulted in a significant reduction in the number of offspring and in the average weight of offspring. The average body length was reduced after pulse exposure to 30 mg/L of dimethoate for 3 h or 70 microg/L of pirimicarb for 4 h, and these exposure concentrations caused a delay in the day for first offspring at exposure durations of 2 to 6 h. The most important new findings in the present study are that short-term (<4 h) pulse exposure of neonates to acetylcholinesterase-inhibiting pesticides caused reproductive damage in D. magna and that repeated-pulse exposure significantly increased mortality in animals that apparently had recovered after a single-pulse exposure. PMID:16704047

  20. The Association between Chronic Arsenic Exposure and Hypertension: A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Tanvir Abir

    2012-01-01

    Full Text Available Background. There is inconclusive evidence from cross-sectional and cohort studies that arsenic exposure is a risk factor involved in the development of hypertension. Methods. A database search, using several keywords, was conducted to identify relevant studies. Separate odds ratio estimates for arsenic exposure with concentration only and arsenic exposure with duration, including biomarker, were extracted from studies that met all inclusion criteria. The extracted odds ratios (OR comparing the highest exposure categories with the lowest in each study were pooled using the random effects methods of meta-analysis. Heterogeneity of odds ratios in the included studies were analyzed using I2 statistics. Results. Eight studies were analyzed. Using the exposure as arsenic concentration in the drinking water, the OR estimate was 1.9 (95% CI: 1.2–3.0, with the I2 = 92%, while using the exposure as concentration and duration, the OR estimate was 1.4 (95% CI: 0.95–2.0 with the I2 = 80%. Meta-regression was done and the quality of exposure measurement was found to be significantly associated with the effect measure. For a one unit increase in the score from exposure assessment, the odds ratio decreased by 6%. No publication bias was evident. The only major weaknesses of this study were heterogeneity across studies and small sample size. Conclusions. The study findings provide limited evidence for a relationship between arsenic and hypertension. In summary, the relationship between arsenic exposure and hypertension is still inconclusive and needs further validation through prospective cohort studies.

  1. Spatial variations in estimated chronic exposure to traffic-related air pollution in working populations: A simulation

    Directory of Open Access Journals (Sweden)

    Cloutier-Fisher Denise

    2008-07-01

    Full Text Available Abstract Background Chronic exposure to traffic-related air pollution is associated with a variety of health impacts in adults and recent studies show that exposure varies spatially, with some residents in a community more exposed than others. A spatial exposure simulation model (SESM which incorporates six microenvironments (home indoor, work indoor, other indoor, outdoor, in-vehicle to work and in-vehicle other is described and used to explore spatial variability in estimates of exposure to traffic-related nitrogen dioxide (not including indoor sources for working people. The study models spatial variability in estimated exposure aggregated at the census tracts level for 382 census tracts in the Greater Vancouver Regional District of British Columbia, Canada. Summary statistics relating to the distributions of the estimated exposures are compared visually through mapping. Observed variations are explored through analyses of model inputs. Results Two sources of spatial variability in exposure to traffic-related nitrogen dioxide were identified. Median estimates of total exposure ranged from 8 μg/m3 to 35 μg/m3 of annual average hourly NO2 for workers in different census tracts in the study area. Exposure estimates are highest where ambient pollution levels are highest. This reflects the regional gradient of pollution in the study area and the relatively high percentage of time spent at home locations. However, for workers within the same census tract, variations were observed in the partial exposure estimates associated with time spent outside the residential census tract. Simulation modeling shows that some workers may have exposures 1.3 times higher than other workers residing in the same census tract because of time spent away from the residential census tract, and that time spent in work census tracts contributes most to the differences in exposure. Exposure estimates associated with the activity of commuting by vehicle to work were

  2. Risk behaviors in a rural community with a known point-source exposure to chronic wasting disease

    Directory of Open Access Journals (Sweden)

    Weeks Jennifer

    2008-06-01

    Full Text Available Abstract Background The emergence and continuing spread of Chronic Wasting Disease (CWD in cervids has now reached 14 U.S. states, two Canadian provinces, and South Korea, producing a potential for transmission of CWD prions to humans and other animals globally. In 2005, CWD spread for the first time from the Midwest to more densely populated regions of the East Coast. As a result, a large cohort of individuals attending a wild game feast in upstate New York were exposed to a deer that was subsequently confirmed positive for CWD. Methods Eighty-one participants who ingested or otherwise were exposed to a deer with chronic wasting disease at a local New York State sportsman's feast were recruited for this study. Participants were administered an exposure questionnaire and agreed to follow-up health evaluations longitudinally over the next six years. Results Our results indicate two types of risks for those who attended the feast, a Feast Risk and a General Risk. The larger the number of risk factors, the greater the risk to human health if CWD is transmissible to humans. Long-term surveillance of feast participants exposed to CWD is ongoing. Conclusion The risk data from this study provide a relative scale for cumulative exposure to CWD-infected tissues and surfaces, and those in the upper tiers of cumulative risk may be most at risk if CWD is transmissible to humans.

  3. Alteration of Blood Parameters and Histoarchitecture of Liver and Kidney of Silver Barb after Chronic Exposure to Quinalphos

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    Golam Mohammod Mostakim

    2015-01-01

    Full Text Available Quinalphos (QP is commonly used for pest control in the agricultural fields surrounding freshwater reservoirs. This study was conducted to evaluate the chronic toxicity of this pesticide on blood parameters and some organs of silver barb, Barbonymus gonionotus. Fish were exposed to two sublethal concentrations, 0.47 ppm and 0.94 ppm, of QP for a period of 28 days. All the blood parameters (red blood cell, hematocrit, and hemoglobin and blood glucose except for white blood cells decreased with increasing concentration of toxicant and become significantly lower (p<0.05 at higher concentration when compared with control. The derived hematological indices of mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration were equally altered compared to control. Histoarchitectural changes of liver and kidney were observed after exposure to the QP. Hypertrophy of hepatocytes, mild to severe necrosis, ruptured central vein, and vacuolation were observed in the liver of treated groups. Highly degenerated kidney tubules and hematopoietic tissue, degeneration of renal corpuscle, vacuolization, and necrosis were evident in the kidney of treated groups. In conclusion, chronic exposure to QP at sublethal concentrations induced hematological and histological alterations in silver barb and offers a simple tool to evaluate toxicity derived alterations.

  4. Effect of chronic exposure to cadmium on serum lipid, lipoprotein and oxidative stress indices in male rats

    Directory of Open Access Journals (Sweden)

    Samarghandian Saeed

    2015-09-01

    Full Text Available Cadmium (Cd is an environmental toxic metal implicated in lipid abnormalities. The present study was designed to elucidate the possible association between chronic exposure to Cd concentration and alterations in plasma lipid, lipoprotein, and oxidative stress indices in rats. Sixteen male rats were assigned to 2 groups of 8 rats each (test and control. The Cd-exposed group obtained drinking water containing cadmium chloride (CdCl2 in the concentration of 2.0 mg Cd/L in drinking water for 3 months. At the end of the experimental period, blood samples were obtained to determine the changes of serum triglycerides (TG, total cholesterol (TC, high-density lipoprotein cholesterol (HDL-C, low-density lipoprotein cholesterol (LDL-C, reduced glutathione (GSH, malondialdehyde (MDA and also serum Cd contents. The results of the present study indicated that Cd administration significantly increased the serum levels of TG, TC, LDL-C, MDA and Cd with reduction in the HDL-C and GSH levels. In conclusion, evidence is presented that chronic exposure to low Cd concentration can adversely affect the lipid and lipoprotein profile via lipid peroxidation.

  5. Altered differential hemocyte count in 3rd instar larvae of Drosophila melanogaster as a response to chronic exposure of Acephate

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    Rajak Prem

    2015-06-01

    Full Text Available Acephate, an organophosphate (OP pesticide, was used to investigate the effects of its chronic exposure on hemocyte abundance in a non-target dipteran insect Drosophila melanogaster. For this purpose, six graded concentrations ranging from 1 to 6 μg/ml were selected, which are below the reported residual values (up to 14 μg/ml of the chemical. 1st instar larvae were fed with these concentrations up to the 3rd instar stage and accordingly hemolymph smears from these larvae were prepared for differential hemocyte count. Three types of cells are found in Drosophila hemolymph, namely, plasmatocytes, lamellocytes and crystal cells. Plasmatocyte count was found to decrease with successive increase in treatment concentrations. Crystal cells showed an increasing trend in their number. Though the number of lamellocytes was very low, a bimodal response was noticed. Lamellocyte number was found to increase with the initial three concentrations, followed by a dose dependent reduction in their number. As hemocytes are directly linked to the immune system of fruit flies, fluctuations in normal titer of these cells may affect insect immunity. Hemocytes share homologies in their origin and mode of action with the immune cells of higher organisms including man. Thus the present findings suggest that immune cells of humans and other organisms may be affected adversely under chronic exposure to Acephate.

  6. Chronic exposure to sublethal hexavalent chromium affects organ histopathology and serum cortisol profile of a teleost, Channa punctatus (Bloch)

    International Nuclear Information System (INIS)

    Effects of chronic exposures (one and two months) to sublethal doses of hexavalent chromium (2 and 4 mg/L potassium dichromate) on organ histopathology and serum cortisol profile were investigated and their overall impact on growth and behavior of a teleost fish, Channa punctatus was elucidated. Histopathological lesions were distinct in the vital organs gill, kidney and liver. The gill lamellae became lifted, fused, and showed oedema. Hyperplasia and hypertrophy of lamellar epithelial cells were distinct with desquamation. Hypertrophy of epithelial cells of renal tubules and reduction in tubular lumens were observed in the trunk kidney. The atrophy of the head kidney interrenal cells and decreased serum cortisol level indicated exhaustion of interrenal activity. Hepatocyte vacuolization and shrinkage, nuclear pyknosis and increase of sinusoidal spaces were observed in the liver. Abnormal behavioral patterns and reduced growth rate were also noticed in the exposed fish. The chronic hexavalent chromium exposure thus by affecting histopathology of gill, kidney (including interrenal tissue) and liver could impair the vital functions of respiration, excretion, metabolic regulation and maintenance of stress homeostasis which in the long-run may pose serious threat to fish health and affect their population.

  7. Chronic neonatal nicotine exposure increases mRNA expression of neurotrophic factors in the postnatal rat hippocampus.

    Science.gov (United States)

    Son, Jong-Hyun; Winzer-Serhan, Ursula H

    2009-06-30

    Nicotine, the psychoactive ingredient in tobacco, can be neuroprotective but the mechanism is unknown. In the adult hippocampus, chronic nicotine can increase expression of growth factors which could contribute to nicotine's neuroprotective effects. During development, nicotine could also increase expression of neurotrophic factors. Therefore, we determined whether chronic neonatal nicotine (CNN) exposure increased mRNA expression levels of brain-derived neurotrophic factor (BDNF), nerve-growth factor (NGF), neurotrophin-3 (NT-3), fibroblast growth factor-2 (FGF-2), and insulin-like growth factor-1 (IGF-1). Nicotine (6 mg/kg/day in milk formula) or milk formula (controls) were delivered in three daily doses via oral gastric intubation to rat pups from postnatal day (P)1 to P8, and then sacrificed. Brains were processed for in situ hybridization using specific (35)S-labeled cRNA probes. At P8, CNN had a significant stimulant treatment effect on the expression of BDNF, FGF-2, NT-3 and IGF-1 [pCNN increased the number of IGF-1-expressing cells in CA1 (18.0%), CA3 (20.9%) and DG (17.7%). Thus, nicotine exposure during early postnatal development differentially up-regulated expression of neurotrophic factor mRNAs in the hippocampus, which could increase neurotrophic tone and alter developmental processes. PMID:19410565

  8. NEUROSENSORY EFFECTS OF CHRONIC HUMAN EXPOSURE TO ARSENIC ASSOCIATED WITH BODY BURDEN AND ENVIRONMENTAL MEASURES

    Science.gov (United States)

    Exposure to arsenic in drinking water is known to produce a variety of health problems including peripheral neuropathy. Auditory, visual and somatosensory impairments have been reported in Mongolian farmers living in the Yellow River Valley where drinking water is contami...

  9. The Neurological Significance of Abnormal Natural Killer Cell Activity in Chronic Toxigenic Mold Exposures

    OpenAIRE

    Ebere Anyanwu; Campbell, Andrew W.; Joseph Jones; Ehiri, John E; Akpan I. Akpan

    2003-01-01

    Toxigenic mold activities produce metabolites that are either broad-spectrum antibiotics or mycotoxins that are cytotoxic. Indoor environmental exposure to these toxigenic molds leads to adverse health conditions with the main outcome measure of frequent neuroimmunologic and behavioral consequences. One of the immune system disorders found in patients presenting with toxigenic mold exposure is an abnormal natural killer cell activity. This paper presents an overview of the neurological signif...

  10. Evidence for effects of chronic lead exposure on blood pressure in experimental animals: an overview.

    OpenAIRE

    Victery, W

    1988-01-01

    Information obtained in a number of experimental studies conducted over the last 40 years on the effects of lead on blood pressure is reviewed. Differences in animal species, age at beginning of exposure, level of lead exposure, indices of lead burden, and blood pressure effects of each study are reported. In several of the high-dose experiments, hypertension was observed, but nephrotoxicity of lead may have contributed to its development. Moreover, in other high-dose experiments, no hyperten...

  11. Chronic Residential Exposure to Particulate Matter Air Pollution and Systemic Inflammatory Markers

    OpenAIRE

    Hoffmann, Barbara; Moebus, Susanne; Dragano, Nico; Stang, Andreas; Möhlenkamp, Stefan; Schmermund, Axel; Memmesheimer, Michael; Bröcker-Preuss, Martina; Mann, Klaus; Erbel, Raimund; Jöckel, Karl-Heinz

    2009-01-01

    Background Long-term exposure to urban air pollution may accelerate atherogenesis, but mechanisms are still unclear. The induction of a low-grade systemic inflammatory state is a plausible mechanistic pathway. Objectives: We analyzed the association of residential long-term exposure to particulate matter (PM) and high traffic with systemic inflammatory markers. Methods We used baseline data from the German Heinz Nixdorf Recall Study, a population-based, prospective cohort study of 4,814 parti...

  12. Chronic exposure to particulate matter and risk of cardiovascular mortality: cohort study from Taiwan

    OpenAIRE

    Tseng, Eva; Ho, Wen-Chao; Lin, Meng-Hung; Cheng, Tsun-Jen; Chen, Pau-Chung; Lin, Hsien-Ho

    2015-01-01

    Background Evidence on the association between long-term exposure to air pollution and cardiovascular mortality is limited in Asian populations. Methods We conducted a cohort study on the association between fine particulate matter (PM2.5) and cardiovascular mortality using 43,227 individuals in a civil servants health service in Taiwan. Each participant was assigned an exposure level of particulate matter based on their district of residence using air pollution data collected by the Taiwan E...

  13. Taurine improves the spatial learning and memory ability impaired by sub-chronic manganese exposure

    OpenAIRE

    Lu, Cai-Ling; Tang, Shen; Meng, Zhi-Juan; He, Yi-Yuan; Song, Ling-Yong; Liu, Yin-Pin; Ma, Ning; Li, Xi-Yi; Guo, Song-Chao

    2014-01-01

    Background Excessive manganese exposure induced cognitive deficit. Several lines of evidence have demonstrated that taurine improves cognitive impairment induced by numerous neurotoxins. However, the role of taurine on manganese-induced damages in learning and memory is still elusive. This goal of this study was to investigate the beneficial effect of taurine on learning and memory capacity impairment by manganese exposure in an animal model. Results The escape latency in the Morris Water Maz...

  14. Chronic toxicity of arsenic, cobalt, chromium and manganese to Hyalella azteca in relation to exposure and bioaccumulation

    Energy Technology Data Exchange (ETDEWEB)

    Norwood, W.P. [Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada) and Aquatic Ecosystems Protection Research Division, Environment Canada, P.O. Box 5050, Burlington, ON L7R 4A6 (Canada)]. E-mail: warren.norwood@ec.gc.ca; Borgmann, U. [Aquatic Ecosystems Protection Research Division, Environment Canada, P.O. Box 5050, Burlington, ON L7R 4A6 (Canada); Dixon, D.G. [Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada)

    2007-05-15

    Chronic toxicity of As, Co, Cr and Mn to Hyalella azteca can be described using a saturation-based mortality model relative to total-body or water metal concentration. LBC25s (total-body metal concentrations resulting in 25% mortality in 4 weeks) were 125, 103, 152 and 57,900 nmol g{sup -1} dry weight for As, Co, Cr and Mn respectively. LC50s (metal concentrations in water resulting in 25% mortality in 4 weeks) were 5600, 183, 731, and 197,000 nmol L{sup -1}, respectively. A hormesis growth response to As exposure was observed. Growth was a more variable endpoint than mortality for all four toxicants; however, confidence limits based on growth and mortality all overlapped, except Cr which had no effect on growth. Mn toxicity was greater in glass test containers compared to plastic. Bioaccumulation of As, Co, Cr, and Mn was strongly correlated with, and is useful for predicting, chronic mortality. - Chronic toxicity of As, Co, Cr and Mn to Hyalella azteca can be described using a saturation-based mortality model in relationship to total-body or water metal concentration.

  15. Effects of prenatal exposure to chronic mild stress and toluene in rats

    DEFF Research Database (Denmark)

    Hougaard, K. S.; Andersen, Maud Bering; Hansen, A. M.;

    2005-01-01

    female offspring of pregnant rats (Mol:WIST) exposed to chronic mild stress (CMS) during gestational days (GD) 9-20, or 1500 ppm toluene, 6 h/day during gestational days 7-20, or a combination of the two. Prenatal CMS was associated with decreased thymic weight and increased auditory startle response...

  16. Pulmonary sensitivity to ozone exposure in sedentary versus chronically trained, female rats.

    Science.gov (United States)

    Gordon, Christopher J; Phillips, Pamela M; Beasley, Tracey E; Ledbetter, A; Aydin, Cenk; Snow, Samantha J; Kodavanti, Urmila P; Johnstone, Andrew F

    2016-06-01

    Epidemiological data suggest that a sedentary lifestyle may contribute to increased susceptibility for some environmental toxicants. We developed an animal model of active versus sedentary life style by providing female Sprague-Dawley rats with continuous access to running wheels. Sedentary rats were housed in standard cages without wheels. After training for 12 wks, rats were exposed to 0, 0.25, 0.5 or 1.0 ppm ozone [O3 for 5 h/d, 1 d/wk, for 6 wk (N = 10 per group)]. Body composition (%fat, lean and fluid) was monitored noninvasively over the course of the study. Ventilatory parameters [tidal volume, minute ventilation, frequency and enhanced pause (Penh)] were assessed using whole-body plethysmography prior to O3 and 24 h after the 5th O3 exposure. Trained rats lost ∼2% body fat after 12 wk of access to running wheels. Peak wheel activity was reduced by 40% after exposure to 1.0 ppm O3. After the 5th O3 exposure, body weight and %fat were reduced in sedentary but not trained rats. Penh was significantly elevated in sedentary but not trained rats the day after exposure to 1.0 ppm O3. However, lung lavage cell counts and biomarkers of pulmonary inflammation measured 1 day after the final exposure were inconsistently affected by training. Wheel running led to marked physiological responses along with some indication of improved pulmonary recovery from O3 exposure. However, wheel running with O3 exposure may also be a detriment for some pulmonary endpoints. Overall, a sedentary lifestyle may increase susceptibility to O3, but additional studies are needed. PMID:27160658

  17. Field measurements of mixed exposure of operators to radioactive aerosol, gas and quartz in confinement of mining equipment cabs during open-pit mining of high-grade uranium ores

    International Nuclear Information System (INIS)

    A series of field measurements of miners mixed exposure to radon and daughters, uranium ore dust and respirable quartz, was conducted in an open-pit mine in Northern Saskatchewan during 1980-81. Control of radon gas levels in the mining equipment cabs is required. Dust may be reduced by minimizing the resuspension of dust from contaminated surfaces within the cabs

  18. New data on uranium nephro-toxicity

    International Nuclear Information System (INIS)

    Uranium is an element and also a heavy metal to which humans can be exposed due to its natural presence or human activities. It has mainly a chemical toxicity on the proximal convoluted tubules of the kidney after acute or chronic exposure. At high dose exposure, acute tubular nephritis is observed, as indicated by proteinuria and a decreased glomerular filtration rate. More recently, the use of structural bio-markers such as beta 2-microglobulin or tubular enzymes has been correlated with histo-pathological injury of the proximal convoluted tubules. During chronic exposure at a low level, the use of some of these sensitive and specific bio-markers would be necessary, particularly when the injury is slight. Recent experimental studies in the laboratory have shown the relevance of such new bio-markers as Kim-1 to detect slight renal injury. Uranium exerts its toxicity on epithelial tubular cells in which it accumulates mainly in the nucleus when it is not precipitated. The mechanisms leading to cell death are not totally elucidated but oxidative stress seems to play an important role. (authors)

  19. Pyranocoumarin Tissue Distribution, Plasma Metabolome and Prostate Transcriptome Impacts of Sub-Chronic Exposure to Korean Angelica Supplement in Mice.

    Science.gov (United States)

    Zhang, Jinhui; Li, Li; Tang, Suni; Zhang, Yong; Markiewski, Maciej; Xing, Chengguo; Jiang, Cheng; Lü, Junxuan

    2016-04-01

    Herbal products containing Korean Angelica gigas Nakai (AGN) root extract are marketed as dietary supplements for memory enhancement, pain killing, and female menopausal symptom relief. We have shown the anticancer activities of AGN supplements in mouse models. To facilitate human anticancer translational research, we characterized the tissue distribution of AGN marker pyranocoumarin compounds decursin (D) and decursinol angelate (DA) ([Formula: see text]% in AGN) and their metabolite decursinol (DOH), assessed the safety of sub-chronic AGN dietary exposure in mice, and explored its impact on plasma aqueous metabolites and the prostate transcriptome. The data show that after a gavage dose, plasma contained readily detectable DOH, but little D and DA, mirroring patterns in the liver. Extra-hepatic tissues retained greater levels of DA and D than the liver did. For sub-chronic exposures, male mice were provided ad libitum AIN93M-pellet diets with 0.5 and 1% AGN for six weeks. No adverse effects were observed on the plasma biochemistry markers of liver and kidney integrity in spite of their enlargement. Histopathological examinations of the liver, kidney and other visceral organs did not reveal tissue abnormalities. Metabolomic assessment of plasma from mice fed the 1%-AGN diet suggested metabolic shifts of key amino acids especially in the methionine-cysteine cycle, purine cycle, and glycolysis-citrate cycle. Prostate transcriptomic profiling identified gene signature changes in the metabolisms of drugs, lipids and cellular energetics, neuro-muscular features, immunity and inflammation, and tumor suppressor/oncogene balance. The safety profile was corroborated with a daily [Formula: see text] injection of AGN extract (100-300[Formula: see text]mg/kg) for four weeks, which resulted in much greater systemic pyranocoumarin exposure than the dietary route did. PMID:27080944

  20. Exposure to chronic mild stress prevents kappa opioid-mediated reinstatement of cocaine and nicotine place preference

    Directory of Open Access Journals (Sweden)

    ReamAl-Hasani

    2013-08-01

    Full Text Available Stress increases the risk of drug abuse, causes relapse to drug seeking, and potentiates the rewarding properties of both nicotine and cocaine. Understanding the mechanisms by which stress regulates the rewarding properties of drugs of abuse provides valuable insight into potential treatments for drug abuse. Prior reports have demonstrated that stress causes dynorphin release, activating kappa-opioid receptors (KOR in monoamine circuits resulting in both potentiation and reinstatement of cocaine and nicotine conditioned place preference. Here we report that kappa-opioid dependent reinstatement of cocaine and nicotine place preference is reduced when the mice are exposed to a randomized chronic mild stress regime prior to training in a conditioned place preference-reinstatement paradigm. The chronic mild stress schedule involves seven different stressors (removal of nesting for 24hr, 5min forced swim stress at 15°C, 8hr food and water deprivation, damp bedding overnight, white noise, cage tilt and disrupted home cage lighting rotated over a three-week period. This response is KOR-selective, because chronic mild stress does not protect against cocaine or nicotine drug-primed reinstatement. This protection from reinstatement is also observed following sub-chronic social defeat stress, where each mouse is placed in an aggressor mouse home cage for a period of 20 min over five days. In contrast, a single acute stressor resulted in a potentiation of KOR-induced reinstatement, similarly to previously reported. Prior studies have shown that stress alters sensitivity to opioids and prior stress can influence the pharmacodynamics of the opioid receptor system. Together, these findings suggest that exposure to different forms of stress may cause a dysregulation of kappa opioid circuitry and that changes resulting from mild stress can have protective and adaptive effects against drug relapse.

  1. Chronic occupational exposure to hexavalent chromium causes DNA damage in electroplating workers

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    Ren Xiao-Bin

    2011-04-01

    Full Text Available Abstract Background Occupational exposure to chromium compounds may result in adverse health effects. This study aims to investigate whether low-level hexavalent chromium (Cr(VI exposure can cause DNA damage in electroplating workers. Methods 157 electroplating workers and 93 control subjects with no history of occupational exposure to chromium were recruited in Hangzhou, China. Chromium levels in erythrocytes were determined by graphite furnace atomic absorption spectrophotometer. DNA damage in peripheral lymphocytes was evaluated with the alkaline comet assay by three parameters: Olive tail moment, tail length and percent of DNA in the comet tail (tail DNA%. Urinary 8-OHdG levels were measured by ELISA. Results Chromium concentration in erythrocytes was about two times higher in electroplating workers (median: 4.41 μg/L than that in control subjects (1.54 μg/L, P P P P Conclusion The findings in this study indicated that there was detectable chromium exposure in electroplating workers. Low-level occupational chromium exposure induced DNA damage.

  2. Honey Bees' Behavior Is Impaired by Chronic Exposure to the Neonicotinoid Thiacloprid in the Field.

    Science.gov (United States)

    Tison, Léa; Hahn, Marie-Luise; Holtz, Sophie; Rößner, Alexander; Greggers, Uwe; Bischoff, Gabriela; Menzel, Randolf

    2016-07-01

    The decline of pollinators worldwide is of growing concern and has been related to the use of plant-protecting chemicals. Most studies have focused on three neonicotinoid insecticides (clothianidin, imidacloprid, and thiamethoxam) currently subject to a moratorium in the EU. Here, we focus on thiacloprid, a widely used cyano-substituted neonicotinoid thought to be less toxic to honey bees and of which use has increased in the last years. Honey bees (Apis mellifera carnica) were exposed chronically to thiacloprid in the field for several weeks at a sublethal concentration. Foraging behavior, homing success, navigation performance, and social communication were impaired, and thiacloprid residue levels increased both in the foragers and the nest mates over time. The effects observed in the field were not due to a repellent taste of the substance. For the first time, we present the necessary data for the risk evaluation of thiacloprid taken up chronically by honey bees in field conditions. PMID:27268938

  3. Estimation of doses to patients with chronic radiation sickness from external occupational exposure

    International Nuclear Information System (INIS)

    The doses to patients with chronic radiation sickness who had engaged in diagnostic radiology have been estimated according to the radiation work load, type and capacity of X-ray equipment, protection conditions, data of nationwide survey on doses to X-ray workers in China, or the data of dose monitoring in working places. Based on the activities of radium sources, time taken up in performing radium therapy, distance to radium sources and radiation work load, the doses to patients who had engaged in radium therapy have been estimated. The results of estimated average doses for 29 cases of chronic radiation sickness are given. Their average red marrow dose, trunk dose and effective dose equivalent are 1.3 Gy, 1.2 Gy and 1.6 Sv, respectively

  4. Effects from offshore oil production: chronic exposure of fish to produced water

    Energy Technology Data Exchange (ETDEWEB)

    Holth, Tor Fredrik

    2009-07-01

    The results of this study demonstrated that environmentally relevant levels of components of produced water may affect condition factor, maturation, biochemical processes and gene expression in fish. The usefulness of bile PAH and AP metabolite measurements to evaluate exposure was demonstrated in two fish species. The development of bio marker responses was shown to depend on exposure regime as well as exposure period. Lysosomal stability (LMS) in cod kidney was related to dose, the effects were observed early (within two weeks) and remained at a stable level throughout the exposure period in fish receiving both continuous and pulsed exposure. Thus, LMS appeared to be a useful marker for effects in Atlantic cod. Formation of DNA adducts in female cod liver was also related to dose, but in contrast to LMS, more than 16 weeks was required for formation of significant levels. This parameter may therefore be underestimated following short-term exposures, such as most offshore fish caging studies (often 4-6 weeks). Although a time-dependent increase was observed, it also required a continuous exposure regime, which is not often observed in the environment. Other bio markers were demonstrated either to adapt or appeared to be insensitive to the exposures. CYP1A activity (EROD) in female cod was responsive on occasion, but a reduction of activity over time was observed. Protein levels of vitellogenin and hepatic CYP1A in zebra fish, as well as AOX in cod kidneys, were not affected in the current study. Gene transcription of several distinct cellular mechanisms was clearly affected in both species, and a predominance of differentially expressed genes in zebra fish was down regulated. This indicated that down-regulation of responsive pathways may be as important or more important than up-regulation. As both presence and absence of effects following pulsed exposure were apparent (DNA adduct formation; oocyte maturation; condition factor), the effects of exposure regime on

  5. Studies on the effects of chronic exposure to mixtures of solvents

    Energy Technology Data Exchange (ETDEWEB)

    Triebig, G.; Bestler, W.; Baumeister, P.; Weltle, D.

    1982-10-01

    In a cross-sectional-study we examined 112 workers with long term exposures to a mixture of solvents (aliphatic and aromatic hydrocarbons, esters, halogenated hydrocarbons) to objectify possible disorders of liver and/or kidneys. Because of the results of air- and biological monitoring and their evaluation according to proposed threshold limit values, the exposure and the body burden is largely tolerable. Dependent on liverspecific parameter (y-GT, GOT, GPT, GLDH) there are slight to moderate elevations in 0 up to 67 cases (0% up to 59%). Parameters of kidney function (creatinine, urea) are always in normal range. After elimination of persons with confounding factors there are no causal connections on group basis between exposure and dysfunctions of liver and kidneys. For the individual the differentiated assessment of occupational and non-occupational hepatotoxic risks is difficult.

  6. Chronic exposure to trichloroethene causes early onset of SLE-like disease in female MRL +/+ mice

    OpenAIRE

    Cai, Ping; König, Rolf; Boor, Paul J; Kondraganti, Shakuntala; Kaphalia, Bhupendra S.; Khan, M. Firoze; Ansari, G.A.S.

    2007-01-01

    Trichloroethene (TCE) exacerbates the development of autoimmune responses in autoimmune-prone MRL +/+ mice. Although TCE-mediated autoimmune responses are associated with an increase in serum immunoglobulins and autoantibodies, the underlying mechanism of autoimmunity is not known. To determine the progression of TCE-mediated immunotoxicity, female MRL +/+ mice were chronically exposed to TCE through the drinking water (0.5 mg/ml of TCE) for various periods of time. Serum concentrations of an...

  7. Within- and among-population level differences in response to chronic copper exposure in southern toads, Anaxyrus terrestris

    International Nuclear Information System (INIS)

    Environmental contaminants are implicated in the global decline of amphibian populations. Copper (Cu) is a widespread contaminant that can be toxic at concentrations just above the normal physiological range. In the present study we examined the effects of chronic Cu aqueous exposure on embryos and larvae of southern toads, Anaxyrus (Bufo) terrestris. Measurable levels of Cu were found in larvae, with tissue concentrations up to 27.5 μg Cu/g dry mass. Aqueous concentrations of Cu as low as 10 μg/L significantly reduced survival to the free-swimming stage and no larvae reached metamorphosis at concentrations above 15 μg/L. Clutches from populations with prior Cu exposure had the lowest survivorship. Among several populations there was significant variation in survivorship at different levels of Cu. More data are needed to understand the underlying causes of within- and among-population resilience to anthropogenic stressors. -- Highlights: ► Southern toad, Anaxyrus terrestris, embryos and larvae are highly sensitive to Cu. ► Significant variation in survivorship exists among clutches and populations. ► Clutches with prior Cu exposure had the lowest survivorship. ► Body burdens in larvae were up to 27.5 μg Cu/g dry mass. -- Capsule: Southern toad aquatic survival is significantly reduced at 15 μg Cu/L with variation in survivorship across clutches and populations

  8. Cancer and non-cancer brain and eye effects of chronic low-dose ionizing radiation exposure

    Directory of Open Access Journals (Sweden)

    Picano Eugenio

    2012-04-01

    Full Text Available Abstract Background According to a fundamental law of radiobiology (“Law of Bergonié and Tribondeau”, 1906, the brain is a paradigm of a highly differentiated organ with low mitotic activity, and is thus radio-resistant. This assumption has been challenged by recent evidence discussed in the present review. Results Ionizing radiation is an established environmental cause of brain cancer. Although direct evidence is lacking in contemporary fluoroscopy due to obvious sample size limitation, limited follow-up time and lack of focused research, anecdotal reports of clusters have appeared in the literature, raising the suspicion that brain cancer may be a professional disease of interventional cardiologists. In addition, although terminally differentiated neurons have reduced or mild proliferative capacity, and are therefore not regarded as critical radiation targets, adult neurogenesis occurs in the dentate gyrus of the hippocampus and the olfactory bulb, and is important for mood, learning/memory and normal olfactory function, whose impairment is a recognized early biomarker of neurodegenerative diseases. The head doses involved in radiotherapy are high, usually above 2 Sv, whereas the low-dose range of professional exposure typically involves lifetime cumulative whole-body exposure in the low-dose range of Conclusions At this point, a systematic assessment of brain (cancer and non-cancer effects of chronic low-dose radiation exposure in interventional cardiologists and staff is needed.

  9. Recent and chronic exposure of wild ducks to lead in human-modified wetlands in Santa Fe Province, Argentina.

    Science.gov (United States)

    Ferreyra, Hebe; Romano, Marcelo; Uhart, Marcela

    2009-07-01

    Poisoning of waterfowl due to ingestion of lead pellets is a worldwide problem in areas that are subject to hunting. No studies have assessed exposure of waterbirds to this heavy metal in Argentina, in spite of intense hunting activity, and the fact that only lead ammunition is commercially available. The objective of this study was to evaluate duck exposure to lead by examining gizzard and bone samples collected from 30 wild ducks, 16 Rosy-billed Pochard (Netta peposaca), and 14 Fulvous Whistling-Duck (Dendrocygna bicolor), provided by hunters in northern Santa Fe Province, Argentina, in July 2007. Radiographs, followed by dissection of the gizzards, showed that 31% of the Rosy-billed Pochards and 29% of the Fulvous Whistling-Ducks had ingested lead pellets (between one and four per animal). Lead in bone was found at concentrations associated with detrimental health effects. In spite of the small number of samples in this project, these results indicate high levels of lead exposure (both recent and chronic) in these species. This is the first report of a problem in Argentina that could represent a threat to the health and conservation of native aquatic species, their predators, and the wetlands they inhabit. PMID:19617495

  10. Chronic diseases and early exposure to airborne mixtures: Part III. Potential origin of pre-menopausal breast cancers.

    Science.gov (United States)

    Argo, James

    2010-03-01

    This is the third in a series dealing with chronic diseases and early exposure to airborne mixtures from industrial releases. The purpose of this study is to increase the understanding of previously unconsidered factors in the physical environment potentially acting as risk factors for female breast cancer. Data are from the Environmental Quality Database containing lifetime residential records for about 20,000 cases, with 1 of 15 cancers and about 5000 controls. Subjects resided within 25 km of all kraft mills, sulfite mills, coke ovens, oil refineries, copper, nickel and lead/zinc smelters operating in Canada in 1967-1970, and were aged or = [DMS] and increases as [DMS] increases. The probability of an adverse effect from early, intermittent and simultaneous exposure to Dioxin and DMS, manifesting as a breast cancer after a latency period of as little as 26 years, is a function of age of first exposure, distance from the source and source type. The most susceptible age cohorts are the youngest. PMID:19337314

  11. Therapeutic and space radiation exposure of mouse brain causes impaired DNA repair response and premature senescence by chronic oxidant production.

    Science.gov (United States)

    Suman, Shubhankar; Rodriguez, Olga C; Winters, Thomas A; Fornace, Albert J; Albanese, Chris; Datta, Kamal

    2013-08-01

    Despite recent epidemiological evidences linking radiation exposure and a number of human ailments including cancer, mechanistic understanding of how radiation inflicts long-term changes in cerebral cortex, which regulates important neuronal functions, remains obscure. The current study dissects molecular events relevant to pathology in cerebral cortex of 6 to 8 weeks old female C57BL/6J mice two and twelve months after exposure to a γ radiation dose (2 Gy) commonly employed in fractionated radiotherapy. For a comparative study, effects of 1.6 Gy heavy ion 56Fe radiation on cerebral cortex were also investigated, which has implications for space exploration. Radiation exposure was associated with increased chronic oxidative stress, oxidative DNA damage, lipid peroxidation, and apoptosis. These results when considered with decreased cortical thickness, activation of cell-cycle arrest pathway, and inhibition of DNA double strand break repair factors led us to conclude to our knowledge for the first time that radiation caused aging-like pathology in cerebral cortical cells and changes after heavy ion radiation were more pronounced than γ radiation. PMID:23928451

  12. Chronic cigarette smoke exposure adversely alters 14C-arachidonic acid metabolism in rat lungs, aortas and platelets

    International Nuclear Information System (INIS)

    Male rats were exposed to freshly generated cigarette smoke once daily, 5 times a week for 10 weeks. Inhalation of smoke was verified by elevated carboxyhemoglobin in blood sampled immediately after smoke exposure and by increased lung aryl hydrocarbon hydroxylase activity 24 hours after the last smoke exposure. Aortic rings isolated from smoke-exposed rats synthesized less prostacyclin (PGI2) from 14C-arachidonic acid than rings from sham rats. Platelets from smoke-exposed rats synthesized more thromboxane (TXA2) from 14C-arachidonic acid than platelets from room controls but not those from sham rats. Lung microsomes from smoke-exposed rats synthesized more TXA2 and had a lower PGI2/TXA2 ratio than lung microsomes from room controls and shams. It is concluded that chronic cigarette smoke exposure alters arachidonic acid metabolism in aortas, platelets and lungs in a manner resulting in decreased PGI2 and increased TXA2, thereby creating a condition favoring platelet aggregation and a variety of cardiovascular diseases

  13. A Case of Bowen’s Disease and Small-Cell Lung Carcinoma: Long-Term Consequences of Chronic Arsenic Exposure in Chinese Traditional Medicine

    OpenAIRE

    Lee, Linda; Bebb, Gwyn

    2004-01-01

    Chronic arsenic toxicity occurs primarily through inadvertent ingestion of contaminated water and food or occupational exposure, but it can also occur through medicinal ingestion. This case features a 53-year-old lifetime nonsmoker with chronic asthma treated for 10 years in childhood with Chinese traditional medicine containing arsenic. The patient was diagnosed with Bowen’s disease and developed extensive-stage small-cell carcinoma of the lung 10 years and 47 years, respectively, after the ...

  14. Chronic Corticosterone Exposure during Adolescence Reduces Impulsive Action but Increases Impulsive Choice and Sensitivity to Yohimbine in Male Sprague-Dawley Rats

    OpenAIRE

    Torregrossa, Mary M.; Xie, Maylene; Taylor, Jane R.

    2012-01-01

    Chronic stress during adolescence is associated with an increased risk for alcoholism and addictive disorders. Addiction is also associated with increased impulsivity, and stress during adolescence could alter cortical circuits responsible for response inhibition. Therefore, the present study determined the effect of chronic exposure to the stress hormone corticosterone (CORT) during adolescence on tests of impulsivity in adulthood and examined possible biochemical mechanisms. Male Sprague-Da...

  15. Chronic exposure to low doses of pharmaceuticals disturbs the hepatic expression of circadian genes in lean and obese mice

    Energy Technology Data Exchange (ETDEWEB)

    Anthérieu, Sébastien; Le Guillou, Dounia; Coulouarn, Cédric; Begriche, Karima [INSERM, U991, Université de Rennes 1, 35000 Rennes (France); Trak-Smayra, Viviane [Pathology Department, Saint-Joseph University, Beirut (Lebanon); Martinais, Sophie [INSERM, U991, Université de Rennes 1, 35000 Rennes (France); Porceddu, Mathieu [Mitologics SAS, Hôpital Robert Debré, 48 Boulevard Sérurier, 75019 Paris (France); Robin, Marie-Anne [INSERM, U991, Université de Rennes 1, 35000 Rennes (France); Fromenty, Bernard, E-mail: bernard.fromenty@inserm.fr [INSERM, U991, Université de Rennes 1, 35000 Rennes (France)

    2014-04-01

    Drinking water can be contaminated with pharmaceuticals. However, it is uncertain whether this contamination can be harmful for the liver, especially during obesity. Hence, the goal of our study was to determine whether chronic exposure to low doses of pharmaceuticals could have deleterious effects on livers of lean and obese mice. To this end, lean and ob/ob male mice were treated for 4 months with a mixture of 11 drugs provided in drinking water at concentrations ranging from 10 to 10{sup 6} ng/l. At the end of the treatment, some liver and plasma abnormalities were observed in ob/ob mice treated with the cocktail containing 10{sup 6} ng/l of each drug. For this dosage, a gene expression analysis by microarray showed altered expression of circadian genes (e.g. Bmal1, Dbp, Cry1) in lean and obese mice. RT-qPCR analyses carried out in all groups of animals confirmed that expression of 8 different circadian genes was modified in a dose-dependent manner. For some genes, a significant modification was observed for dosages as low as 10{sup 2}–10{sup 3} ng/l. Drug mixture and obesity presented an additive effect on circadian gene expression. These data were validated in an independent study performed in female mice. Thus, our study showed that chronic exposure to trace pharmaceuticals disturbed hepatic expression of circadian genes, particularly in obese mice. Because some of the 11 drugs can be found in drinking water at such concentrations (e.g. acetaminophen, carbamazepine, ibuprofen) our data could be relevant in environmental toxicology, especially for obese individuals exposed to these contaminants. - Highlights: • The contamination of drinking water with drugs may have harmful effects on health. • Some drugs can be more hepatotoxic in the context of obesity and fatty liver. • Effects of chronic exposure of trace drugs were studied in lean and obese mouse liver. Drugs and obesity present additive effects on circadian gene expression and toxicity. • Trace

  16. Chronic exposure to low doses of pharmaceuticals disturbs the hepatic expression of circadian genes in lean and obese mice

    International Nuclear Information System (INIS)

    Drinking water can be contaminated with pharmaceuticals. However, it is uncertain whether this contamination can be harmful for the liver, especially during obesity. Hence, the goal of our study was to determine whether chronic exposure to low doses of pharmaceuticals could have deleterious effects on livers of lean and obese mice. To this end, lean and ob/ob male mice were treated for 4 months with a mixture of 11 drugs provided in drinking water at concentrations ranging from 10 to 106 ng/l. At the end of the treatment, some liver and plasma abnormalities were observed in ob/ob mice treated with the cocktail containing 106 ng/l of each drug. For this dosage, a gene expression analysis by microarray showed altered expression of circadian genes (e.g. Bmal1, Dbp, Cry1) in lean and obese mice. RT-qPCR analyses carried out in all groups of animals confirmed that expression of 8 different circadian genes was modified in a dose-dependent manner. For some genes, a significant modification was observed for dosages as low as 102–103 ng/l. Drug mixture and obesity presented an additive effect on circadian gene expression. These data were validated in an independent study performed in female mice. Thus, our study showed that chronic exposure to trace pharmaceuticals disturbed hepatic expression of circadian genes, particularly in obese mice. Because some of the 11 drugs can be found in drinking water at such concentrations (e.g. acetaminophen, carbamazepine, ibuprofen) our data could be relevant in environmental toxicology, especially for obese individuals exposed to these contaminants. - Highlights: • The contamination of drinking water with drugs may have harmful effects on health. • Some drugs can be more hepatotoxic in the context of obesity and fatty liver. • Effects of chronic exposure of trace drugs were studied in lean and obese mouse liver. Drugs and obesity present additive effects on circadian gene expression and toxicity. • Trace pharmaceuticals could

  17. Chronic aflatoxin exposure in children living in Bhaktapur, Nepal: Extension of the MAL-ED study

    Science.gov (United States)

    Fumonisin B1 (FB1) and aflatoxin B1 (AFB1) are toxic chemicals produced by molds. The molds that produce these two toxic chemicals are commonly found in corn and their co-occurence in corn has been demonstrated in many surveys. This study was conducted because it is suspected that exposure to eith...

  18. Sub-chronic lung inflammation after airway exposures to Bacillus thuringiensis biopesticides in mice

    DEFF Research Database (Denmark)

    Barfod, Kenneth K; Poulsen, Steen Seier; Hammer, Maria;

    2010-01-01

    The aim of the present study was to assess possible health effects of airway exposures to Bacillus thuringiensis (Bt) based biopesticides in mice. Endpoints were lung inflammation e