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Sample records for acute cadmium fume

  1. Flow injection determination of lead and cadmium in hair samples from workers exposed to welding fumes

    A flow injection procedure involving continuous acid leaching for lead and cadmium determination in hair samples of persons in permanent contact with a polluted workplace environment by flame atomic absorption spectrometry is proposed. Variables such as sonication time, nature and concentration of the acid solution used as leaching solution, leaching temperature, flow-rate of the continuous manifold, leaching solution volume and hair particle size were simultaneously studied by applying a Plackett-Burman design approach. Results showed that nitric acid concentration (leaching solution), leaching temperature and sonication time were statistically significant variables (confidence interval of 95%). These last two variables were finally optimised by using a central composite design. The proposed procedure allowed the determination of cadmium and lead with limits of detection 0.1 and 1.0 μg g-1, respectively. The accuracy of the developed procedure was evaluated by the analysis of a certified reference material (CRM 397, human hair, from the BCR). The proposed method was applied with satisfactory results to the determination of Cd and Pb in human hair samples of workers exposed to welding fumes

  2. Biomonitoring for iron, manganese, chromium, aluminum, nickel and cadmium in workers exposed to welding fume: a preliminary study

    Mulyana

    2015-05-01

    Full Text Available The control of exposure to welding fumes is increasing importance in promoting a healthy, safe and productive work environment. This study is a case-control design, random study was conducted among welder (56 subjects and non welder (39 subjects with more than 1 years experience in the same job task in an automotive parts manufactory within the industrial area at Cikarang in 2013. All subjects were completed physical examination, informed consent and questionnaire. Blood heavy metals were determined by Inductively-Coupled Plasma Mass Spectrometry (ICP-MS. Whole blood iron, manganese, chromium and lead in welder were higher than non-welder, but not different for aluminum, nickel and cadmium. In welder, chromium and manganese correlated with smoking status, cadmium correlated with age and smoking status. In multivariate analysis, wholeblood cadmium correlates with age and smoking status.

  3. Acute Inhalation Exposure to Titanium Ethanolate as a Possible Cause of Metal Fume Fever

    M Ahmadimanesh

    2014-04-01

    Full Text Available Occupational inhalation exposure to noxious agents is not uncommon. Herein, we present a 26-year-old male student who had accidental acute inhalation exposure to a large quantity of titanium ethanolate and hydrogen chloride in chemistry lab. He was referred to the emergency department of our hospital with low-grade fever, dyspnea, headache, fatigue and myalgia. After 24 hrs of symptomatic treatment (oxygen therapy and acetaminophen, the fever was subsided and the patient discharged home in a good clinical condition. The presented symptoms could be interpreted as a form of metal fume fever. It can therefore be concluded that organo-metallic compound of titanium metal may have the potential to produce metal fume fever in human.

  4. Health hazards of welding fumes

    Even in the twenty -first century , welding is still a common and high skilled occupation. The hazardous agents associated with welding processes are acetylene, carbomonoxide, oxides of nitrogen, ozone, phosgene, tungsten, arsenic, beryllium, cadmium, iron, copper, lead, manganese, nickel, silver,tin and zinc.All welding processes involve the potential hazards for inhalation exposures that may lead to acute or chronic respiratory diseases. According to literature described earlier it has been suggested that welding fumes cause the lung function impairment, obstructive and restrictive,lungs diseases diseases, cough, dyspnea, rhinitis, asthama, pneumoconiosis, carcinoma of the lungs. In additon,welding workers suffer from eye problems like irritation, phtokeratitis, cataract, skin irritation, erythema, petrygium, non-melanosytic skin cancer, malignant melanoma, reduced sperm count , motility and infertility. Most of the studies have been attempted previously to evaluate the effects of weldig fumes.However no cllectively effort illuminating the general effects of welding fumes on differnt organs or systems or both in humans has not been published. Therefore, the aim of this review is to gather the potential toxic effects of welding fumes documented by individual efforts and provides information to community on hazards of welding. (author)

  5. Reduction of Acute Inflammatory Effects of Fumed Silica Nanoparticles in the Lung by Adjusting Silanol Display through Calcination and Metal Doping.

    Sun, Bingbing; Pokhrel, Suman; Dunphy, Darren R; Zhang, Haiyuan; Ji, Zhaoxia; Wang, Xiang; Wang, Meiying; Liao, Yu-Pei; Chang, Chong Hyun; Dong, Juyao; Li, Ruibin; Mädler, Lutz; Brinker, C Jeffrey; Nel, André E; Xia, Tian

    2015-09-22

    The production of pyrogenic (fumed) silica is increasing worldwide at a 7% annual growth rate, including expanded use in food, pharmaceuticals, and other industrial products. Synthetic amorphous silica, including fumed silica, has been generally recognized as safe for use in food products by the Food and Drug Administration. However, emerging evidence from experimental studies now suggests that fumed silica could be hazardous due to its siloxane ring structure, high silanol density, and "string-of-pearl-like" aggregate structure, which could combine to cause membrane disruption, generation of reactive oxygen species, pro-inflammatory effects, and liver fibrosis. Based on this structure-activity analysis (SAA), we investigated whether calcination and rehydration of fumed silica changes its hazard potential in the lung due to an effect on silanol density display. This analysis demonstrated that the accompanying change in surface reactivity could indeed impact cytokine production in macrophages and acute inflammation in the lung, in a manner that is dependent on siloxane ring reconstruction. Confirmation of this SAA in vivo, prompted us to consider safer design of fumed silica properties by titanium and aluminum doping (0-7%), using flame spray pyrolysis. Detailed characterization revealed that increased Ti and Al doping could reduce surface silanol density and expression of three-membered siloxane rings, leading to dose-dependent reduction in hydroxyl radical generation, membrane perturbation, potassium efflux, NLRP3 inflammasome activation, and cytotoxicity in THP-1 cells. The reduction of NLRP3 inflammasome activation was also confirmed in bone-marrow-derived macrophages. Ti doping, and to a lesser extent Al doping, also ameliorated acute pulmonary inflammation, demonstrating the possibility of a safer design approach for fumed silica, should that be required for specific use circumstances. PMID:26200133

  6. Protective role of carnosine in mice with cadmium-induced acute hepatotoxicity.

    Fouad, Amr A; Qureshi, Habib A; Yacoubi, Mohamed T; Al-Melhim, Walid N

    2009-11-01

    The hepatoprotective effect of carnosine was investigated against cadmium-induced acute liver injury in mice. Hepatotoxicity was induced by a single i.p. injection of cadmium chloride (6.5mg/kg). Carnosine treatment (10mg/kg/day, i.p.) was applied for three consecutive days, starting one day before cadmium administration. Carnosine significantly decreased the cadmium-induced elevations in serum aminotransferases. Carnosine suppressed lipid peroxidation and restored the deficits in the antioxidant defense mechanisms (reduced glutathione level, and catalase and superoxide dismutase activities) in liver tissue resulted from cadmium administration. Also, the reductions in hepatic nitric oxide and zinc ion levels, and the increases in hepatic cadmium ion concentration, and myeloperoxidase and caspase-3 activities following cadmium exposure were significantly attenuated by carnosine treatment. In addition, carnosine markedly ameliorated cadmium-induced liver tissue damage as evidenced by light and electron microscopic examinations. It was concluded that carnosine can be considered a potential candidate to protect the liver against the deleterious effect of acute cadmium intoxication. PMID:19748544

  7. Reviews of the environmental effects of pollutants: IV. Cadmium

    Hammons, A.S.; Huff, J.E.; Braunstein, H.M.; Drury, J.S.; Shriner, C.R.; Lewis, E.B.; Whitfield, B.L.; Towill, L.E.

    1978-06-01

    This report is a comprehensive, multidisciplinary review of the health and environmental effects of cadmium and specific cadmium derivatives. More than 500 references are cited. The cadmium body burden in animals and humans results mainly from the diet. In the United States, the normal intake of cadmium for adult humans is estimated at about 50 ..mu..g per day. Tobacco smoke is a significant additional source of cadmium exposure. The kidneys and liver together contain about 50% of the total cadmium body burden. Acute cadmium poisoning is primarily an occupational problem, generally from inhalation of cadmium fumes or dusts. In the general population, incidents of acute poisoning by inhaled or ingested cadmium or its compounds are relatively rare. The kidney is the primary target organ for toxicity from prolonged low-level exposure to cadmium. No causal relationship has been established between cadmium exposure and human cancer, although a possible link between cadmium and prostate cancer has been indicated. Cadmium has been shown to be teratogenic in rats, hamsters, and mice, but no such effects have been proven in humans. Cadmium has been reported to increase the frequency of chromosomal aberrations in cultured Chinese hamster ovary cells and in human peripheral leukocytes. The major concern about environmental cadmium is the potential effects on the general population. There is no substantial evidence of hazard from current levels of cadmium in air, water, or food. However, because cadmium is a cumulative poison and because present intake provides a relatively small safety margin, there are adequate reasons for concern over possible future increases in background levels.

  8. Reviews of the environmental effects of pollutants: IV. Cadmium

    This report is a comprehensive, multidisciplinary review of the health and environmental effects of cadmium and specific cadmium derivatives. More than 500 references are cited. The cadmium body burden in animals and humans results mainly from the diet. In the United States, the normal intake of cadmium for adult humans is estimated at about 50 μg per day. Tobacco smoke is a significant additional source of cadmium exposure. The kidneys and liver together contain about 50% of the total cadmium body burden. Acute cadmium poisoning is primarily an occupational problem, generally from inhalation of cadmium fumes or dusts. In the general population, incidents of acute poisoning by inhaled or ingested cadmium or its compounds are relatively rare. The kidney is the primary target organ for toxicity from prolonged low-level exposure to cadmium. No causal relationship has been established between cadmium exposure and human cancer, although a possible link between cadmium and prostate cancer has been indicated. Cadmium has been shown to be teratogenic in rats, hamsters, and mice, but no such effects have been proven in humans. Cadmium has been reported to increase the frequency of chromosomal aberrations in cultured Chinese hamster ovary cells and in human peripheral leukocytes. The major concern about environmental cadmium is the potential effects on the general population. There is no substantial evidence of hazard from current levels of cadmium in air, water, or food. However, because cadmium is a cumulative poison and because present intake provides a relatively small safety margin, there are adequate reasons for concern over possible future increases in background levels

  9. Drug-induced acute tubulointerstitial nephritis: a case with elevated urinary cadmium.

    Subat-Dezulović, Mirna; Slavić, Irena; Rozmanić, Vojko; Persić, Mladen; Medjimurec, Branka; Sćukanec-Spoljar, Mira

    2002-05-01

    Acute tubulointerstitial nephritis (ATIN) has many different causes, but is most frequently caused by drugs. We report a 13-year-old vegetarian girl with drug-induced ATIN, confirmed by renal biopsy, and simultaneous occurrence of elevated urinary cadmium. Four weeks prior to admission she had been treated with antibiotics and acetaminophen for respiratory infection, and remaining febrile, was treated with different "home-made" herbal mixtures. She presented with acute non-oliguric renal failure, tubular dysfunction, and sterile pyuria, but without skin rash or edema. Laboratory data showed a raised erythrocyte sedimentation rate, normal white blood count with eosinophilia, and a serum creatinine of 245 micromol/l. Urinalysis was remarkable for glycosuria, tubular proteinuria, and elevated beta(2)-microglobulin and N-acetyl-beta-D-glucosaminidase excretion. Immunoserological tests characteristic of acute glomerulonephritis and systemic diseases were negative. She was treated with steroids and her renal function improved. Follow-up analyses disclosed normal urinary cadmium and enzyme excretion within 6 months. Heavy metal analysis of herbal preparations that she had taken confirmed the presence of cadmium, but within approved concentrations. In conclusion, elevated urinary cadmium in the case of drug-induced ATIN may be assumed to be an accidental finding. However, consumption of different herbs containing cadmium and cadmium-induced nephro-toxicity could be the reason for such serious renal damage. PMID:12042900

  10. Nrf2 activation prevents cadmium-induced acute liver injury

    Oxidative stress plays an important role in cadmium-induced liver injury. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that up-regulates cytoprotective genes in response to oxidative stress. To investigate the role of Nrf2 in cadmium-induced hepatotoxicity, Nrf2-null mice, wild-type mice, kelch-like ECH-associated protein 1-knockdown (Keap1-KD) mice with enhanced Nrf2, and Keap1-hepatocyte knockout (Keap1-HKO) mice with maximum Nrf2 activation were treated with cadmium chloride (3.5 mg Cd/kg, i.p.). Blood and liver samples were collected 8 h thereafter. Cadmium increased serum alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) activities, and caused extensive hepatic hemorrhage and necrosis in the Nrf2-null mice. In contrast, Nrf2-enhanced mice had lower serum ALT and LDH activities and less morphological alternations in the livers than wild-type mice. H2DCFDA (2′,7′-dichlorodihydrofluoresein diacetate) staining of primary hepatocytes isolated from the four genotypes of mice indicated that oxidative stress was higher in Nrf2-null cells, and lower in Nrf2-enhanced cells than in wild-type cells. To further investigate the mechanism of the protective effect of Nrf2, mRNA of metallothionein (MT) and other cytoprotective genes were determined. Cadmium markedly induced MT-1 and MT-2 in livers of all four genotypes of mice. In contrast, genes involved in glutathione synthesis and reducing reactive oxygen species, including glutamate-cysteine ligase (Gclc), glutathione peroxidase-2 (Gpx2), and sulfiredoxin-1 (Srxn-1) were only induced in Nrf2-enhanced mice, but not in Nrf2-null mice. In conclusion, the present study shows that Nrf2 activation prevents cadmium-induced oxidative stress and liver injury through induction of genes involved in antioxidant defense rather than genes that scavenge Cd. -- Highlights: ► Cadmium caused extensive hepatic hemorrhage and necrosis in Nrf2-null mice. ► Keap1-KD and Keap1-HKO mice were

  11. Nrf2 activation prevents cadmium-induced acute liver injury

    Wu, Kai C. [Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Liu, Jie J. [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Klaassen, Curtis D., E-mail: cklaasse@kumc.edu [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States)

    2012-08-15

    Oxidative stress plays an important role in cadmium-induced liver injury. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that up-regulates cytoprotective genes in response to oxidative stress. To investigate the role of Nrf2 in cadmium-induced hepatotoxicity, Nrf2-null mice, wild-type mice, kelch-like ECH-associated protein 1-knockdown (Keap1-KD) mice with enhanced Nrf2, and Keap1-hepatocyte knockout (Keap1-HKO) mice with maximum Nrf2 activation were treated with cadmium chloride (3.5 mg Cd/kg, i.p.). Blood and liver samples were collected 8 h thereafter. Cadmium increased serum alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) activities, and caused extensive hepatic hemorrhage and necrosis in the Nrf2-null mice. In contrast, Nrf2-enhanced mice had lower serum ALT and LDH activities and less morphological alternations in the livers than wild-type mice. H{sub 2}DCFDA (2′,7′-dichlorodihydrofluoresein diacetate) staining of primary hepatocytes isolated from the four genotypes of mice indicated that oxidative stress was higher in Nrf2-null cells, and lower in Nrf2-enhanced cells than in wild-type cells. To further investigate the mechanism of the protective effect of Nrf2, mRNA of metallothionein (MT) and other cytoprotective genes were determined. Cadmium markedly induced MT-1 and MT-2 in livers of all four genotypes of mice. In contrast, genes involved in glutathione synthesis and reducing reactive oxygen species, including glutamate-cysteine ligase (Gclc), glutathione peroxidase-2 (Gpx2), and sulfiredoxin-1 (Srxn-1) were only induced in Nrf2-enhanced mice, but not in Nrf2-null mice. In conclusion, the present study shows that Nrf2 activation prevents cadmium-induced oxidative stress and liver injury through induction of genes involved in antioxidant defense rather than genes that scavenge Cd. -- Highlights: ► Cadmium caused extensive hepatic hemorrhage and necrosis in Nrf2-null mice. ► Keap1-KD and Keap1-HKO mice

  12. Gene networks and toxicity pathways induced by acute cadmium exposure in adult largemouth bass (Micropterus salmoides)

    Mehinto, Alvine C., E-mail: alvinam@sccwrp.org [Southern California Coastal Water Research Project, Costa Mesa, CA 92626 (United States); Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States); Prucha, Melinda S. [Department of Human Genetics, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322 (United States); Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States); Colli-Dula, Reyna C.; Kroll, Kevin J.; Lavelle, Candice M.; Barber, David S. [Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States); Vulpe, Christopher D. [Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720 (United States); Denslow, Nancy D. [Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States)

    2014-07-01

    Highlights: • Low-level acute cadmium exposure elicited tissue-specific gene expression changes. • Molecular initiating events included oxidative stress and disruption of DNA repair. • Metallothionein, a marker of metal exposure, was not significantly affected. • We report effects of cadmium on cholesterol metabolism and steroid synthesis. • Diabetic complications and impaired reproduction are potential adverse outcomes. - Abstract: Cadmium is a heavy metal that can accumulate to toxic levels in the environment leading to detrimental effects in animals and humans including kidney, liver and lung injuries. Using a transcriptomics approach, genes and cellular pathways affected by a low dose of cadmium were investigated. Adult largemouth bass were intraperitoneally injected with 20 μg/kg of cadmium chloride (mean exposure level – 2.6 μg of cadmium per fish) and microarray analyses were conducted in the liver and testis 48 h after injection. Transcriptomic profiles identified in response to cadmium exposure were tissue-specific with the most differential expression changes found in the liver tissues, which also contained much higher levels of cadmium than the testis. Acute exposure to a low dose of cadmium induced oxidative stress response and oxidative damage pathways in the liver. The mRNA levels of antioxidants such as catalase increased and numerous transcripts related to DNA damage and DNA repair were significantly altered. Hepatic mRNA levels of metallothionein, a molecular marker of metal exposure, did not increase significantly after 48 h exposure. Carbohydrate metabolic pathways were also disrupted with hepatic transcripts such as UDP-glucose, pyrophosphorylase 2, and sorbitol dehydrogenase highly induced. Both tissues exhibited a disruption of steroid signaling pathways. In the testis, estrogen receptor beta and transcripts linked to cholesterol metabolism were suppressed. On the contrary, genes involved in cholesterol metabolism were highly

  13. Gene networks and toxicity pathways induced by acute cadmium exposure in adult largemouth bass (Micropterus salmoides)

    Highlights: • Low-level acute cadmium exposure elicited tissue-specific gene expression changes. • Molecular initiating events included oxidative stress and disruption of DNA repair. • Metallothionein, a marker of metal exposure, was not significantly affected. • We report effects of cadmium on cholesterol metabolism and steroid synthesis. • Diabetic complications and impaired reproduction are potential adverse outcomes. - Abstract: Cadmium is a heavy metal that can accumulate to toxic levels in the environment leading to detrimental effects in animals and humans including kidney, liver and lung injuries. Using a transcriptomics approach, genes and cellular pathways affected by a low dose of cadmium were investigated. Adult largemouth bass were intraperitoneally injected with 20 μg/kg of cadmium chloride (mean exposure level – 2.6 μg of cadmium per fish) and microarray analyses were conducted in the liver and testis 48 h after injection. Transcriptomic profiles identified in response to cadmium exposure were tissue-specific with the most differential expression changes found in the liver tissues, which also contained much higher levels of cadmium than the testis. Acute exposure to a low dose of cadmium induced oxidative stress response and oxidative damage pathways in the liver. The mRNA levels of antioxidants such as catalase increased and numerous transcripts related to DNA damage and DNA repair were significantly altered. Hepatic mRNA levels of metallothionein, a molecular marker of metal exposure, did not increase significantly after 48 h exposure. Carbohydrate metabolic pathways were also disrupted with hepatic transcripts such as UDP-glucose, pyrophosphorylase 2, and sorbitol dehydrogenase highly induced. Both tissues exhibited a disruption of steroid signaling pathways. In the testis, estrogen receptor beta and transcripts linked to cholesterol metabolism were suppressed. On the contrary, genes involved in cholesterol metabolism were highly

  14. Visibility in sodium fume

    The appearance of sodium fume of unknown concentration and the effects of short term exposure on unprotected workers is described. The molecular extinction coefficient of sodium fume is calculated from which light transmission data, and a rapid method for the estimation of the fume concentration is proposed. (author)

  15. Gender Differences in Acute Cadmium-Induced Systemic Inflammation in Rats

    MILENA KATARANOVSKI; SRDJA JANKOVI(C); DRAGAN KATARANOVSKI; JELENA (S)TOSI(C); DESA BOGOJEVI(C)

    2009-01-01

    Objective To examine the presence of gender differences in pro-inflammatory potential of cadmium in rats by comparing systemic inflammatory response to acute cadmium intoxication in animals of the two sexes. Methods Basic aspects of this response were evaluated, including plasma levels of inflammatory cytokines tumor necrosis factor (TNF) and interleukin-6 (IL-6) and of major rat acute phase protein alpha 2-macroglobulin (alpha2-M), as soluble indicators of inflammation, and the number and activity of peripheral blood leukocytes, as cellular indicators of inflammation. Results Differential increases of IL-6 and alpha 2-M (higher in males than in females) in peripheral blood cell counts and types (leukocytosis and shift in the ratio of granulocytes to lymphocytes more pronounced in males vs females) and in levels of neutrophil priming (higher in males vs females) were noted. Conclusion The data document a more intense inflammatory response to cadmium administration in males. The sex differences in inflammatory effects of cadmium might be taken into consideration in studying the toxicity of this heavy metal.

  16. Field and laboratory tests on acute toxicity of cadmium to freshwater crayfish

    1986-09-01

    Environmental regulatory standards for cadmium (EPA 1980), like those for most pollutants, are based on acute, laboratory toxicity tests of single species. Such tests can be conducted rapidly and inexpensively in comparison to acute or chronic field studies, but their validity has often been questioned. Laboratory-based criteria are subject to two criticisms: (1) chemical and physical conditions differ greatly in degree and variability from laboratory to field, and (2) species are not isolated, but live in an ecosystem of interacting taxa and biofeedback. To investigate the validity of basing field toxicity standards on laboratory data, the authors subjected the freshwater crayfish Orconectes immunis for 96 h to various levels of cadmium in laboratory aquaria and experimental ponds. The study was designed to evaluate in part the first criticism of lab-based criteria. The studies were conducted concurrently with similar short-term experiments on the fathead minnow, Pimephales promelas, and coincided with studies of chronic cadmium stress on fathead minnows in experimental ponds.

  17. Development of a biotic ligand model to predict the acute toxicity of cadmium to Daphnia pulex

    The goal of this study was to develop a biotic ligand model (BLM) to predict the acute toxicity of cadmium to Daphnia pulex. Organisms were cultured in moderately soft water and standard 48 h acute toxicity tests were used to determine EC50s in various water chemistries where the effects of Ca2+, Na+, Mg2+, Cl-, K+, pH, and two sources of natural organic matter (Suwannee River and Nordic Reservoir) were evaluated. Overall, toxicity responses were consistent with the free-ion activity model and the principles inherent in the BLM. Increases in Ca2+ resulted in higher EC50s, indicating that Cd2+ competes with Ca2+ for uptake at the biotic ligand. Similar cation competition effects were observed when Mg2+ was varied but with a less pronounced protective effect relative to Ca2+. Changes in Na+ and K+ concentrations had no significant effect on Cd toxicity. EC50 values did not change significantly when pH was adjusted over a range from 8.0 to 6.1. Additions of natural organic matter resulted in elevated dissolved organic carbon (DOC) concentrations that significantly reduced Cd bioavailability via complexation of Cd2+. An existing biotic ligand model (HydroQual BLM ver 2.2.3) was tested for its ability to predict acute Cd toxicity to D. pulex. Once the BLM was adjusted for the relatively sensitivity of D. pulex the protective effects of Ca and DOC could be predicted reasonably well but other test chemistries did not match with measured EC50s. Binding constants derived from the test results were used to develop a modified BLM for the effects of Cd on D. pulex that accounted for the moderating effect of Ca and Mg on acute toxicity but overestimated the protective effect of DOC.

  18. Development of a biotic ligand model to predict the acute toxicity of cadmium to Daphnia pulex

    Clifford, Matthew [Department of Biology, Wilfrid Laurier University, Waterloo, ON N2L 3C5 (Canada); McGeer, James C., E-mail: jmcgeer@wlu.ca [Department of Biology, Wilfrid Laurier University, Waterloo, ON N2L 3C5 (Canada)

    2010-06-01

    The goal of this study was to develop a biotic ligand model (BLM) to predict the acute toxicity of cadmium to Daphnia pulex. Organisms were cultured in moderately soft water and standard 48 h acute toxicity tests were used to determine EC50s in various water chemistries where the effects of Ca{sup 2+}, Na{sup +}, Mg{sup 2+}, Cl{sup -}, K{sup +}, pH, and two sources of natural organic matter (Suwannee River and Nordic Reservoir) were evaluated. Overall, toxicity responses were consistent with the free-ion activity model and the principles inherent in the BLM. Increases in Ca{sup 2+} resulted in higher EC50s, indicating that Cd{sup 2+} competes with Ca{sup 2+} for uptake at the biotic ligand. Similar cation competition effects were observed when Mg{sup 2+} was varied but with a less pronounced protective effect relative to Ca{sup 2+}. Changes in Na{sup +} and K{sup +} concentrations had no significant effect on Cd toxicity. EC50 values did not change significantly when pH was adjusted over a range from 8.0 to 6.1. Additions of natural organic matter resulted in elevated dissolved organic carbon (DOC) concentrations that significantly reduced Cd bioavailability via complexation of Cd{sup 2+}. An existing biotic ligand model (HydroQual BLM ver 2.2.3) was tested for its ability to predict acute Cd toxicity to D. pulex. Once the BLM was adjusted for the relatively sensitivity of D. pulex the protective effects of Ca and DOC could be predicted reasonably well but other test chemistries did not match with measured EC50s. Binding constants derived from the test results were used to develop a modified BLM for the effects of Cd on D. pulex that accounted for the moderating effect of Ca and Mg on acute toxicity but overestimated the protective effect of DOC.

  19. Acute cadmium intoxication induces alpha-class glutathione S-transferase protein synthesis and enzyme activity in rat liver

    Acute cadmium intoxication affects glutathione S-transferase (GST) in rat liver. It has been found that 24 h after i.p. cadmium administration to rats, at a dose of 2.5 mg CdCl2 kg-1 body weight, the activity of this enzyme in liver cytosol increased by 40%. A less stimulatory effect persisted till 48 h and thereafter the enzyme activity normalized. Since, GST isoenzymes belong to different classes in mammalian tissues, we used quantitative immunoassays to verify which family of GST isoenzymes is influenced by this intoxication. Only alpha-class glutathione S-transferase (α-GST) proteins were detected in rat liver cytosol and their level increased by about 25%, 24 h after cadmium treatment. No pi-GST isoforms were found in liver cytosol from either normal or cadmium-treated rats. Co-administration of actinomycin D with cadmium normalized both the protein level and the activity of α-GST, suggesting that some effect occurs on enzyme transcription of these isoenzymes by this metal. On the other hand, it seems unlikely that the stimulatory effect is due to the high level of peroxides caused by lipid peroxidation, since Vitamin E administration strongly reduced the TBARS level, but did not cause any GST activity decrease

  20. Acute cadmium administration to rats exerts both immunosuppressive and proinflammatory effects in spleen

    Highlights: • The effect of cadmium on splenic T and innate immune cells in rats is explored. • Differential effects of 1 mg/kg on T cell and innate immune activities were shown. • Lower Cd dose (0.5 mg/kg) cause less pronounced immunosuppressive effects. • Proinflammatory effects on innate immune activities were seen at that dose. • Presented data depict complexity of immunomodulatory potential of this metal. - Abstract: Conflicting data (both suppression and augmentation as well as lack of the effect) exist in respect to cadmium (Cd) and splenic T cell-based immune cell activity. Spleen is also the site of innate immune responses but impact of Cd on this type of immunity has been less explored. In the present study the effects of acute Cd administration on basic aspects of both T cell-based and innate immune spleen cell activity were examined in rats. Intraperitoneal injection of 1 mg of Cd/kg resulted in decrease in concanavalin A (ConA) induced proliferation which seems to be more related to altered spleen cells responsiveness to IL-2 than to apoptosis. Differential effects on proinflammatory T cell derived cytokines were observed (decreases of IFN-γ gene expression and ConA-stimulated production, but increases in IL-17 mRNA levels with no effect on concentrations of protein product). Reduction of IFN-γ production seemed not to rely on IL-4 and IL-10, but at least partly on nitric oxide (NO). Increased activity relevant for innate immunity (granulocyte and CD11b+ cell accumulation in the spleen, inducible nitric oxide synthase/iNOS expression and NO production by spleen cells) was observed, but there was a decrease in respiratory burst (dihydrorhodamine/DHR oxidation and nitroblue tetrazolium/NBT reduction). Increases of TNF-α and IL-1β gene expression and IL-1β protein product were noted as well. Administration of 0.5 mg Cd/kg resulted in less pronounced (ConA-induced proliferation) or lack of the effect (IFN-γ production) on spleen T cell

  1. Acute toxicity profile of cadmium revealed by proteomics in brain tissue of Paralichthys olivaceus: Potential role of transferrin in cadmium toxicity

    An analytical approach using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) separated proteins from the brain tissue of the fish Paralichthys olivaceus. Approximately 600 protein spots were detected from the brain sample when applying 600 μg protein to a 2D-PAGE gel in the pH range 3.5-10.0. Compared to a control sample, significant changes of 24 protein spots were observed in the fish tissue exposed to acute toxicity of seawater cadmium (SCAT) at 10 ppm for 24 h. Among these spots, nine were down-regulated, nine were up-regulated, two showed high expression, and four showed low expression. The collected spots were identified by peptide mass fingerprinting (PMF) and database search, and they were further classified by LOCtree, a hierarchical system of support vector machines which predict their sub-cellular localization. The amount of transferrin expression in brain cells decreased linearly with the increase of SCAT concentration in seawater. Among the 24 proteins identified on a 2D-PAGE gel, 9 demonstrated a synchronous response to acute cadmium, suggesting that they might represent a biomarker profile. Based on their variable levels and trends on the 2D-PAGE gel this protein (likely to be transferrin) suggesting they might be utilized as biomarkers to investigate cadmium pollution levels in seawater and halobios survival, as well as to evaluate the degree of risk of human fatalities. The results indicate that the application of multiple biomarkers has an advantage over a single biomarker for monitoring levels of environmental contamination

  2. Acute toxicity profile of cadmium revealed by proteomics in brain tissue of Paralichthys olivaceus: Potential role of transferrin in cadmium toxicity

    Zhu Jinyong [Department of Biochemistry and Biotechnology, School of Life Sciences, Xiamen University, Xiamen 361005 (China); State Key Laboratory of Physical Chemistry of Solid Surface, Xiamen University, Xiamen 361005 (China); Huang Heqing [Department of Biochemistry and Biotechnology, School of Life Sciences, Xiamen University, Xiamen 361005 (China) and State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005 (China) and State Key Laboratory of Physical Chemistry of Solid Surface, Xiamen University, Xiamen 361005 (China)]. E-mail: hqhuang@xmu.edu.cn; Bao Xiaodong [Department of Biochemistry and Biotechnology, School of Life Sciences, Xiamen University, Xiamen 361005 (China); Lin Qingmei [Department of Biochemistry and Biotechnology, School of Life Sciences, Xiamen University, Xiamen 361005 (China); State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005 (China); Cai Zongwei [Department of Biochemistry and Biotechnology, School of Life Sciences, Xiamen University, Xiamen 361005 (China); Department of Chemistry, Hong Kong Baptist University, Hong Kong (China)

    2006-06-15

    An analytical approach using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) separated proteins from the brain tissue of the fish Paralichthys olivaceus. Approximately 600 protein spots were detected from the brain sample when applying 600 {mu}g protein to a 2D-PAGE gel in the pH range 3.5-10.0. Compared to a control sample, significant changes of 24 protein spots were observed in the fish tissue exposed to acute toxicity of seawater cadmium (SCAT) at 10 ppm for 24 h. Among these spots, nine were down-regulated, nine were up-regulated, two showed high expression, and four showed low expression. The collected spots were identified by peptide mass fingerprinting (PMF) and database search, and they were further classified by LOCtree, a hierarchical system of support vector machines which predict their sub-cellular localization. The amount of transferrin expression in brain cells decreased linearly with the increase of SCAT concentration in seawater. Among the 24 proteins identified on a 2D-PAGE gel, 9 demonstrated a synchronous response to acute cadmium, suggesting that they might represent a biomarker profile. Based on their variable levels and trends on the 2D-PAGE gel this protein (likely to be transferrin) suggesting they might be utilized as biomarkers to investigate cadmium pollution levels in seawater and halobios survival, as well as to evaluate the degree of risk of human fatalities. The results indicate that the application of multiple biomarkers has an advantage over a single biomarker for monitoring levels of environmental contamination.

  3. Mechanism of acute cadmium toxicity in the testis of the rat: a cellular and molecular inquiry

    The more sensitive Sertoli cells were chosen as a model to investigate a molecular mechanism of toxicity. Primary rat Sertoli cells were exposed to sublethal concentrations of cadmium and the changes in [32P]-orthophosphate-labelled phosphoproteins using two-dimensional polyacrylamide gel electrophoresis were examined. Resultant autoradiograms showed a delayed dose- and time-dependent increase in intensity of two acidic proteins having identical molecular weights. These changes were most probably a result of increased synthesis of the proteins. Pretreatment of the cells with zinc, a cadmium antagonist, partially reduced the effect of cadmium. This research concludes that Sertoli cells are relatively more sensitive to the effects of cadmium than interstitial cells. A time- and dose dependent increase in [32P]-associated activity to two small Sertoli cell phosphoproteins was consistently seen after cadmium exposure, whereas no effect could be seen using essential, non-toxic metals. This response may be an early indicator in the disruption of cellular homeostasis by cadmium, and will hopefully contribute positive evidence in the search for a molecular mechanism of cadmium toxicity

  4. Developing acute-to-chronic toxicity ratios for lead, cadmium, and zinc using rainbow trout, a mayfly, and a midge

    Mebane, C.A.; Hennessy, D.P.; Dillon, F.S.

    2008-01-01

    In order to estimate acute-to-chronic toxicity ratios (ACRs) relevant to a coldwater stream community, we exposed rainbow trout (Oncorhynchus mykiss) to cadmium (Cd), lead (Pb), and zinc (Zn) in 96-h acute and 60+ day early-life stage (ELS) exposures. We also tested the acute and sublethal responses of a mayfly (Baetis tricaudatus) and a midge (Chironomus dilutus, formerly C. tentans) with Pb. We examine the statistical interpretation of test endpoints and the acute-to-chronic ratio concept. Increasing the number of control replicates by 2 to 3x decreased the minimum detectable differences by almost half. Pb ACR estimates mostly increased with increasing acute resistance of the organisms (rainbow trout ACRs trout and Cd were 0.6 and 0.95; Zn about 1.0; and for Pb 3.3 and 11. The comparable Pb ACRs for the mayfly and Chironomus were 5.2 and 51 respectively. Our rainbow trout ACRs with Pb were about 5-20x lower than earlier reports with salmonids. We suggest discounting previous ACR results that used larger and older fish in their acute tests. ?? 2007 GovernmentEmployee: U.S. Geological Survey.

  5. Development of a model to predict the effect of water chemistry on the acute toxicity of cadmium to Photobacterium phosphoreum

    Highlights: • Acute cadmium toxicity was evaluated with P. phosphoreum as a test organism. • The effect of Ca2+, Mg2+, K+, pH and complexants on Cd toxicity was investigated. • Each factor has its own distinct characteristics on the toxicity-modifying effects. • A model was developed to predict Cd toxicity towards P. phosphoreum. -- Abstract: Cadmium (Cd) compounds are widely distributed toxic environmental and industrial pollutants, and they may bring danger to growth and development of aquatic organisms. The effects of Ca2+ (as CaCl2), Mg2+ (as MgSO4), K+ (as KCl), pH and complexants (EDTA, the commercial DOM, and three homemade DOMs) on Cd toxicity to Photobacterium phosphoreum were evaluated in standardized 15 min acute toxicity tests. Increases in Ca2+ concentration resulted in higher EC50 values, indicating the competition between the two ions for uptake sites at the biotic ligand. Increased waterborne Mg2+ also reduced Cd toxicity, but to a slightly lesser degree compared with Ca2+. The overall decline in EC50 data with increasing K+ in test solutions suggested that Cd toxicity was enhanced at larger K+ concentration. The toxicity alleviation by H+ was observed over the tested pH range of 5.0–9.0. Additions of complexing agents into the exposure water reduced Cd bioavailability via complexation of Cd2+, and complexants from different sources displayed different protective effect. The influence of these toxicity modifying factors was finally incorporated into a model that can predict acute cadmidum toxicity for Photobacterium phosphoreum. After validation with laboratory and natural waters, the developed model could support efforts to improve the ecological relevance of presently applied risk assessment procedures

  6. Development of a model to predict the effect of water chemistry on the acute toxicity of cadmium to Photobacterium phosphoreum

    Qu, Ruijuan; Wang, Xinghao [State Key Laboratory of Pollution Control and Resources Reuse, School of Environment, Xianlin Campus, Nanjing University, Jiangsu Nanjing 210023 (China); Liu, Zhengtao; Yan, Zhenguang [State Key Laboratory of Environmental Criteria and Risk Assessment and State Environmental Protection Key Laboratory of Ecological Effect and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Wang, Zunyao, E-mail: wangzun315cn@163.com [State Key Laboratory of Pollution Control and Resources Reuse, School of Environment, Xianlin Campus, Nanjing University, Jiangsu Nanjing 210023 (China)

    2013-11-15

    Highlights: • Acute cadmium toxicity was evaluated with P. phosphoreum as a test organism. • The effect of Ca{sup 2+}, Mg{sup 2+}, K{sup +}, pH and complexants on Cd toxicity was investigated. • Each factor has its own distinct characteristics on the toxicity-modifying effects. • A model was developed to predict Cd toxicity towards P. phosphoreum. -- Abstract: Cadmium (Cd) compounds are widely distributed toxic environmental and industrial pollutants, and they may bring danger to growth and development of aquatic organisms. The effects of Ca{sup 2+} (as CaCl{sub 2}), Mg{sup 2+} (as MgSO{sub 4}), K{sup +} (as KCl), pH and complexants (EDTA, the commercial DOM, and three homemade DOMs) on Cd toxicity to Photobacterium phosphoreum were evaluated in standardized 15 min acute toxicity tests. Increases in Ca{sup 2+} concentration resulted in higher EC{sub 50} values, indicating the competition between the two ions for uptake sites at the biotic ligand. Increased waterborne Mg{sup 2+} also reduced Cd toxicity, but to a slightly lesser degree compared with Ca{sup 2+}. The overall decline in EC{sub 50} data with increasing K{sup +} in test solutions suggested that Cd toxicity was enhanced at larger K{sup +} concentration. The toxicity alleviation by H{sup +} was observed over the tested pH range of 5.0–9.0. Additions of complexing agents into the exposure water reduced Cd bioavailability via complexation of Cd{sup 2+}, and complexants from different sources displayed different protective effect. The influence of these toxicity modifying factors was finally incorporated into a model that can predict acute cadmidum toxicity for Photobacterium phosphoreum. After validation with laboratory and natural waters, the developed model could support efforts to improve the ecological relevance of presently applied risk assessment procedures.

  7. Cytochemical study of carp neutrophil granulocytes after acute exposure to cadmium

    Drastichová, J.; Švestková, E.; Lusková, Věra; Svobodová, Z.

    2005-01-01

    Roč. 21, č. 3 (2005), s. 215-219. ISSN 0175-8659 Institutional research plan: CEZ:AV0Z60930519 Keywords : peripheral-blood leukocytes * cadmium * common carp Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.563, year: 2005

  8. Rat liver glutathione S-transferase activity stimulation following acute cadmium or manganese intoxication

    The effect of cadmium or manganese administration on rat liver glutathione S-transferase (GST) has been investigated. The activity of this enzyme in liver cytosol, where almost all the cellular activity is present, had increased by more than 36% 24 h after a single i.p. injection of CdCl2 (2.5 mg kg-1 b.w.) or MnCl2 (2.0 mg kg-1 b.w.). After shorter and longer time intervals, a lower enzyme activity stimulation was observed in both cases. When liver cytosol was incubated for 10 min with 75 μM CdCl2 or 40 μM MnCl2, no effect was observed on enzyme activity. The increase in GST following cadmium or manganese administration was blocked by prior administration of actinomycin D, indicative of a possible transcription-dependent response. The liver soluble GST from both control and metal-treated rats was not at all affected by Vitamin E, in the range of 20-300 μM. By contrast, hematin was seen to be a competitive inhibitor of this liver enzyme from both types of rats by using CDNB as substrate and the Ki value was equal to 0.22 μM. The possibility that under the conditions used class alpha GST isoenzymes are affected by cadmium or manganese is discussed

  9. Opiatergic participation in the thirst-inhibiting effect of acute third ventricle injections of cadmium (Cd2+ and lead (Pb2+

    E. De-Castro-e-Silva

    1998-06-01

    Full Text Available We have previously demonstrated that acute third ventricle injections of both lead and cadmium prevent the dipsogenic response elicited by dehydration or by central injections of dipsogenic agents such as angiotensin II, carbachol and isoproterenol in rats. We have also shown that the antidipsogenic action of cadmium may be due, at least in part, to activation of thirst-inhibitory central serotonergic pathways. In the present paper we show that in Wistar male rats the antidipsogenic effect of both lead acetate (3.0 nmol/rat and cadmium chloride (3.0 nmol/rat may be partially dependent on the activation of brain opiatergic pathways since central injections of naloxone (82.5 nmol/rat, a non-selective opioid antagonist, blunt the thirst-inhibiting effect of these metals. One hundred and twenty minutes after the second third ventricle injections, dehydrated animals (14 h overnight receiving saline + sodium acetate displayed a high water intake (7.90 ± 0.47 ml/100 g body weight whereas animals receiving saline + lead acetate drank 3.24 ± 0.47 ml/100 g body weight. Animals receiving naloxone + lead acetate drank 6.94 ± 0.60 ml/100 g body weight. Animals receiving saline + saline drank 8.16 ± 0.66 ml/100 g body weight whilst animals receiving saline + cadmium chloride drank 1.63 ± 0.37 ml/100 g body weight. Animals receiving naloxone + cadmium chloride drank 8.01 ± 0.94 ml/100 g body weight. It is suggested that acute third ventricle injections of both lead and cadmium exert their antidipsogenic effect by activating thirst-inhibiting opioid pathways in the brain.

  10. Novel characterization of welding fumes

    Complete text of publication follows. The lung deposition of welding fume comprised of a large number of primary nanoparticles, occurs predominantly in the alveolar region. The particle size distribution of welding fumes is an important factor determining the bioaccessibility of metal components and the hazard potential of pro-inflammatory effects driven largely by soluble and insoluble transition metals. Several techniques are frequently used for determining the particle size distribution of different welding fumes. A scanning mobility particle sizer (SMPS) offers the opportunity of temporal particle-size distribution measurements and to follow the changes in particle number concentration, a transmission electron microscope (TEM) is capable of visualizing the individual particle morphology and measuring the particle size of primary particles. Are the results obtained with these two techniques comparable? To answer this question welding fumes were generated by different welding methods and examined by a SMPS in the range of 10 to 487 nanometers. The SMPS instrument measures the size distribution of fine particles by separating particles based on electrical-mobility. Particles of a selected size are detected optically, using a detection technology in which small particle visibility is enhanced by growing the particles in a condensing butyl alcohol vapour. Samples were collected on TEM grids made of nickel, copper and silicon for primary particle characterization by TEM. Particle size distributions with both analytical techniques were determined. The most obvious features of the TEM analysis were that the primary welding fume particles had a tendency to form chainlike agglomerates in case of all welding, and almost no individual primary particles were found. It is quite unclear how these agglomerates are detected by the SMPS. An important finding of the chemical analysis of the particles by TEM was that the larger particles contained cores of more volatile components

  11. Effect of acute exposure to cadmium on the expression of heat-shock and hormone-nuclear receptor genes in the aquatic midge Chironomus riparius

    Planello, R.; Martinez-Guitarte, J.L. [Grupo de Biologia y Toxicologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, UNED, Senda del Rey 9, 28040 Madrid (Spain); Morcillo, G., E-mail: gmorcillo@ccia.uned.es [Grupo de Biologia y Toxicologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, UNED, Senda del Rey 9, 28040 Madrid (Spain)

    2010-03-01

    Cadmium is a widespread and highly toxic pollutant of particular ecotoxicological relevance for aquatic ecosystems where it accumulates. To identify biomarkers for ecotoxicity monitoring, the effect of cadmium on the expression of different genes related to the stress response as well as to the ecdysone hormone-signalling pathway was studied in the aquatic larvae of Chironomus riparius (Diptera, Chironomidae), a standard test organism in aquatic toxicology testing. Reverse Transcription Polymerase Chain Reaction (RT-PCR) was used to evaluate the effects of acute and short-term cadmium exposures (10 mM CdCl{sub 2}, 12 h and 24 h) on the expression of hsp70, hsc70, hsp90 and hsp40 genes, as well as on that of the ecdysone hormonal-receptor genes (EcR and usp). A significant 3-fold increase in the level of hsp70 gene transcripts was induced by the treatment, whereas neither the other stress genes tested (hsp90 and hsp40) nor the constitutive form of hsp70, hsc70, was affected in the larvae exposed to cadmium. These results show that hsp70 is differentially activated to other environmentally regulated heat-shock genes, and constitutes a biomarker of exposure to this toxic metal. In addition, we also found that cadmium is able to alter the expression of the ecdysone receptor gene (EcR), whose mRNA level is significantly increased whereas usp levels remained unaltered. This finding, evidenced for the first time in invertebrates, supports the view that cadmium has the ability to mimic the effect of the hormone by the activation of the ecdysone nuclear receptor, which may partly explain the endocrine disruption capability that has been previously suggested for this toxic metal. Our research adds to the growing evidence implicating heavy metals, and cadmium in particular, as potential endocrine disruptive agents and may have significant implications for ecological risk assessment of endocrine-disrupting compounds in invertebrates.

  12. Effect of acute exposure to cadmium on the expression of heat-shock and hormone-nuclear receptor genes in the aquatic midge Chironomus riparius

    Cadmium is a widespread and highly toxic pollutant of particular ecotoxicological relevance for aquatic ecosystems where it accumulates. To identify biomarkers for ecotoxicity monitoring, the effect of cadmium on the expression of different genes related to the stress response as well as to the ecdysone hormone-signalling pathway was studied in the aquatic larvae of Chironomus riparius (Diptera, Chironomidae), a standard test organism in aquatic toxicology testing. Reverse Transcription Polymerase Chain Reaction (RT-PCR) was used to evaluate the effects of acute and short-term cadmium exposures (10 mM CdCl2, 12 h and 24 h) on the expression of hsp70, hsc70, hsp90 and hsp40 genes, as well as on that of the ecdysone hormonal-receptor genes (EcR and usp). A significant 3-fold increase in the level of hsp70 gene transcripts was induced by the treatment, whereas neither the other stress genes tested (hsp90 and hsp40) nor the constitutive form of hsp70, hsc70, was affected in the larvae exposed to cadmium. These results show that hsp70 is differentially activated to other environmentally regulated heat-shock genes, and constitutes a biomarker of exposure to this toxic metal. In addition, we also found that cadmium is able to alter the expression of the ecdysone receptor gene (EcR), whose mRNA level is significantly increased whereas usp levels remained unaltered. This finding, evidenced for the first time in invertebrates, supports the view that cadmium has the ability to mimic the effect of the hormone by the activation of the ecdysone nuclear receptor, which may partly explain the endocrine disruption capability that has been previously suggested for this toxic metal. Our research adds to the growing evidence implicating heavy metals, and cadmium in particular, as potential endocrine disruptive agents and may have significant implications for ecological risk assessment of endocrine-disrupting compounds in invertebrates.

  13. Potentiated interaction between ineffective doses of budesonide and formoterol to control the inhaled cadmium-induced up-regulation of metalloproteinases and acute pulmonary inflammation in rats.

    Wenhui Zhang

    Full Text Available The anti-inflammatory properties of glucocorticoids are well known but their protective effects exerted with a low potency against heavy metals-induced pulmonary inflammation remain unclear. In this study, a model of acute pulmonary inflammation induced by a single inhalation of cadmium in male Sprague-Dawley rats was used to investigate whether formoterol can improve the anti-inflammatory effects of budesonide. The cadmium-related inflammatory responses, including matrix metalloproteinase-9 (MMP-9 activity, were evaluated. Compared to the values obtained in rats exposed to cadmium, pretreatment of inhaled budesonide (0.5 mg/15 ml elicited a significant decrease in total cell and neutrophil counts in bronchoalveolar lavage fluid (BALF associated with a significant reduction of MMP-9 activity which was highly correlated with the number of inflammatory cells in BALF. Additionally, cadmium-induced lung injuries characterized by inflammatory cell infiltration within alveoli and the interstitium were attenuated by the pre-treatment of budesonide. Though the low concentration of budesonide (0.25 mg/15 ml exerted a very limited inhibitory effects in the present rat model, its combination with an inefficient concentration of formoterol (0.5 mg/30 ml showed an enhanced inhibitory effect on neutrophil and total cell counts as well as on the histological lung injuries associated with a potentiation of inhibition on the MMP-9 activity. In conclusion, high concentration of budesonide alone could partially protect the lungs against cadmium exposure induced-acute neutrophilic pulmonary inflammation via the inhibition of MMP-9 activity. The combination with formoterol could enhance the protective effects of both drugs, suggesting a new therapeutic strategy for the treatment of heavy metals-induced lung diseases.

  14. Comparison of stainless and mild steel welding fumes in generation of reactive oxygen species

    Frazer David

    2010-11-01

    Full Text Available Abstract Background Welding fumes consist of a wide range of complex metal oxide particles which can be deposited in all regions of the respiratory tract. The welding aerosol is not homogeneous and is generated mostly from the electrode/wire. Over 390,000 welders were reported in the U.S. in 2008 while over 1 million full-time welders were working worldwide. Many health effects are presently under investigation from exposure to welding fumes. Welding fume pulmonary effects have been associated with bronchitis, metal fume fever, cancer and functional changes in the lung. Our investigation focused on the generation of free radicals and reactive oxygen species from stainless and mild steel welding fumes generated by a gas metal arc robotic welder. An inhalation exposure chamber located at NIOSH was used to collect the welding fume particles. Results Our results show that hydroxyl radicals (.OH were generated from reactions with H2O2 and after exposure to cells. Catalase reduced the generation of .OH from exposed cells indicating the involvement of H2O2. The welding fume suspension also showed the ability to cause lipid peroxidation, effect O2 consumption, induce H2O2 generation in cells, and cause DNA damage. Conclusion Increase in oxidative damage observed in the cellular exposures correlated well with .OH generation in size and type of welding fumes, indicating the influence of metal type and transition state on radical production as well as associated damage. Our results demonstrate that both types of welding fumes are able to generate ROS and ROS-related damage over a range of particle sizes; however, the stainless steel fumes consistently showed a significantly higher reactivity and radical generation capacity. The chemical composition of the steel had a significant impact on the ROS generation capacity with the stainless steel containing Cr and Ni causing more damage than the mild steel. Our results suggest that welding fumes may cause acute

  15. Copper, but not cadmium, is acutely toxic for trout hepatocytes: short-term effects on energetics and ion homeostasis

    The toxic effects of cadmium (Cd) and copper (Cu) on cellular energy metabolism and ion homeostasis were investigated in hepatocytes from the rainbow trout, Oncorhynchus mykiss. The metal content of cells did not increase during incubation with Cu, whereas a dose-dependent increase was seen with Cd. Cell viability was unaffected in the presence of 100 μM Cd and 10 μM Cu but was significantly reduced after 30 min of exposure to 100 μM Cu, both in the presence and absence of extracellular calcium. Oxygen consumption (VO2) was not affected by 100 μM Cd or 10 μM Cu, whereas 100 μM Cu caused a significant and calcium-dependent increase of VO2. Lactate production and basal glucose release were not altered by either of the metals. However, the epinephrine-stimulated rate of glucose release was significantly reduced after 2 h of incubation with 100 μM Cu. Hepatocytes exposed to Cd showed only a marginal increase of intracellular free calcium (Cai2+), whereas with Cu a pronounced and dose-dependent increase of Cai2+ was induced after a delay of 10 to 15 min, the calcium being of extracellular origin. Intracellular pH was not altered by Cd but decreased significantly in the presence of Cu. Overall our data demonstrate that Cu, but not Cd, is acutely toxic for trout hepatocytes. Since Cu does not enter the cells in the short term it appears to exert its acutely toxic effects at the cell membrane. Although Cu toxicity is associated with an uptake of calcium from extracellular space, leading to an elevation of cellular respiration, cytotoxicity does not appear to be dependent on the presence of extracellular calcium

  16. Acute effects of cadmium on osmoregulation of the freshwater teleost Prochilodus lineatus: enzymes activity and plasma ions.

    Silva, Alexandre O F da; Martinez, Cláudia B R

    2014-11-01

    Cadmium (Cd) is a trace element that is very toxic to fish. It is commonly found in surface waters contaminated with industrial effluents. When dissolved in water, Cd can rapidly cause physiological changes in the gills and kidneys of freshwater fish. The objective of this study was to evaluate the acute effects of Cd on the osmoregulation of the Neotropical fish Prochilodus lineatus. Juvenile fish were exposed to Cd at two concentrations [1 (Cd1) and 10 (Cd10) μgL(-1)] for 24 and 96h. The effects of Cd were evaluated through the analysis of ions (Na(+), K(+), Ca(2+), and Cl(-)) and plasma osmolality, and by measuring the activities of enzymes involved in osmoregulation obtained from the gills and kidney. Fish exposed to Cd for 24 and 96h showed a decrease in Na(+)/K(+)-ATPase activity in the gills and kidney. The activity of carbonic anhydrase decreased in the gills after 24h and in both tissues after 96h of Cd exposure. The gill Ca(2+)-ATPase activity also decreased with Cd exposure, with a concomitant drop in the plasma concentration of Ca(2+). Despite the hypocalcemia, there were no changes in the concentration of the ions Na(+), K(+), and Cl(-) or in plasma osmolality. Among the enzymes involved in ion transport, H(+)-ATPase was the only enzyme that showed increased activity in gills, whereas its activity in kidney remained unchanged. The results of this study demonstrate that waterborne Cd at the maximum concentrations set by Brazilian guidelines for freshwater affects the gills and kidney functions of P. lineatus. Acute exposure to Cd resulted in the decrease of the activity of enzymes, which culminated with the loss of the fish's ability to regulate the levels of calcium in the blood, leading to hypocalcemia. PMID:25203423

  17. Different compensatory mechanisms in two metal-accumulating aquatic macrophytes exposed to acute cadmium stress in outdoor artificial lakes.

    Sanità di Toppi, Luigi; Vurro, Emanuela; Rossi, Laura; Marabottini, Rosita; Musetti, Rita; Careri, Maria; Maffini, Monica; Mucchino, Claudio; Corradini, Claudio; Badiani, Maurizio

    2007-06-01

    Mechanisms underlying cadmium (Cd) detoxification were compared in two aquatic macrophytes commonly used in phytoremediation, namely Pistia stratiotes L. and Eichhornia crassipes (Mart.) Solms. To simulate Cd pollution in the open environment, plants growing in outdoor artificial lakes were exposed for 21d to either 25 or 100microM Cd, in two consecutive years. Toxicity symptoms were absent or mild in both species. Metal accumulation was much higher in the roots of P. stratiotes, whereas in E. crassipes a comparatively higher fraction was translocated to the leaves. In both species, Cd was neither included in phenolic polymers or Ca-oxalate crystals, nor altered the levels of Cd-complexing organic acids. Glutathione levels were constitutively remarkably higher and much more responsive to Cd exposure in P. stratiotes than in E. crassipes. Abundant phytochelatin synthesis occurred only in P. stratiotes, both in roots and in leaves. In E. crassipes, on the other side, the constitutive levels of some antioxidant enzymes and ascorbate were higher and more responsive to Cd than in P. stratiotes. Thus, in these two aquatic plants grown in the open, different detoxification mechanisms might come into play to counterbalance Cd acute stress. PMID:17292445

  18. Sensitivity of mottled sculpins (Cottus bairdi) and rainbow trout (Onchorhynchus mykiss) to acute and chronic toxicity of cadmium, copper, and zinc

    Besser, J.M.; Mebane, C.A.; Mount, D.R.; Ivey, C.D.; Kunz, J.L.; Greer, I.E.; May, T.W.; Ingersoll, C.G.

    2007-01-01

    Studies of fish communities of streams draining mining areas suggest that sculpins (Cottus spp.) may be more sensitive than salmonids to adverse effects of metals. We compared the toxicity of zinc, copper, and cadmium to mottled sculpin (C. bairdi) and rainbow trout (Onchorhynchus mykiss) in laboratory toxicity tests. Acute (96-h) and early life-stage chronic (21- or 28-d) toxicity tests were conducted with rainbow trout and with mottled sculpins from populations in Minnesota and Missouri, USA, in diluted well water (hardness = 100 mg/L as CaCO3). Acute and chronic toxicity of metals to newly hatched and swim-up stages of mottled sculpins differed between the two source populations. Differences between populations were greatest for copper, with chronic toxicity values (ChV = geometric mean of lowest-observed-effect concentration and no-observed-effect concentration) of 4.4 ??g/L for Missouri sculpins and 37 ??g/L for Minnesota sculpins. Cadmium toxicity followed a similar trend, but differences between sculpin populations were less marked, with ChVs of 1.1 ??g/L (Missouri) and 1.9 ??g/L (Minnesota). Conversely, zinc was more toxic to Minnesota sculpins (ChV = 75 ??g/L) than Missouri sculpins (chronic ChV = 219 ??g/L). Species-average acute and chronic toxicity values for mottled sculpins were similar to or lower than those for rainbow trout and indicated that mottled sculpins were among the most sensitive aquatic species to toxicity of all three metals. Our results indicate that current acute and chronic water quality criteria for cadmium, copper, and zinc adequately protect rainbow trout but may not adequately protect some populations of mottled sculpins. Proposed water quality criteria for copper based on the biotic ligand model would be protective of both sculpin populations tested. ?? 2007 SETAC.

  19. The Pozzolanic reaction of silica fume

    Jensen, Ole Mejlhede

    2012-01-01

    Silica fume is a very important supplementary cementitious binder in High-Performance and Ultra High-Performance Concretes. Through its pozzolanic reaction the silica fume densifies the concrete micro-structure, in particular it strengthens the paste-aggregate interfacial transition zone. In the...... present paper different aspects of the pozzolanic reaction of silica fume are investigated. These include chemical shrinkage, isothermal heat development and strength development. Key data for these are given and compared with theoretical calculations, and based on presented measurements the energy of...... activation of the pozzolanic reaction of silica fume is estimated. The results show that the pozzolanic reaction of silica fume has notable differences from Portland cement hydration....

  20. A protective effect of dietary calcium against acute waterborne cadmium uptake in rainbow trout

    The present study examined the interactions between elevated dietary calcium (as ionic Ca2+ in the form of CaCl2·2H2O) and acute waterborne Cd exposure (50 μg/l as CdNO3 for 3 h) on whole body uptake and internal distribution of newly accumulated Cd, Ca2+, and Na+ in juvenile rainbow trout (Oncorhynchus mykiss). Fish were fed with three diets 20 (control), 30 and 60 mg Ca2+/g food: for 7 days before fluxes were measured with radiotracers over a 3 h period. The two elevated Ca2+ diets reduced the whole body uptake of both Ca2+ and Cd by >50% and similarly reduced the internalization of both newly accumulated metals in most tissues, effects which reflect the shared branchial uptake route for Ca2+ and Cd. As the Ca2+ concentrations of the fluid phases of the stomach and intestinal contents were greatly elevated by the experimental diets, increased gastrointestinal Ca2+ uptake likely caused the down-regulation of the branchial Ca2+ (and Cd) uptake pathway. Waterborne Na+ uptake and internal distribution were not affected. While plasma Ca2+ surged after the first two feedings of the 60 mg Ca2+/g diet, internal homeostasis was quickly restored. Total Ca2+, Na+, and Cl- levels in tissues were not affected by diets. While dietary Ca2+ protected against waterborne Cd uptake, it did not protect against the relative inhibition of waterborne Ca2+ uptake caused by waterborne Cd. Acute exposure to 50 μg/l Cd reduced the uptake and internalization of newly accumulated Ca2+ (but not Na+) by 70% or more, regardless of diet. Since elevated dietary Ca2+ reduces waterborne Cd uptake, fish eating a Ca2+-rich invertebrate diet may be more protected against waterborne Cd toxicity in a field situation

  1. Acute effects of cadmium on osmoregulation of the freshwater teleost Prochilodus lineatus: Enzymes activity and plasma ions

    Highlights: • Cd effects were evaluated on plasma ions and ATPases of Prochilodus lineatus. • Fish were exposed to 1 and 10 μg Cd L−1 for 24 and 96 h. • Na+/K+-ATPase and carbonic anhydrase decreased in gills and kidney after Cd exposure. • Gill Ca2+-ATPase and plasma Ca2+ decreased after Cd exposure. • Cd concentrations set by Brazilian guidelines affect Ca2+ regulation of P. lineatus. - Abstract: Cadmium (Cd) is a trace element that is very toxic to fish. It is commonly found in surface waters contaminated with industrial effluents. When dissolved in water, Cd can rapidly cause physiological changes in the gills and kidneys of freshwater fish. The objective of this study was to evaluate the acute effects of Cd on the osmoregulation of the Neotropical fish Prochilodus lineatus. Juvenile fish were exposed to Cd at two concentrations [1 (Cd1) and 10 (Cd10) μg L−1] for 24 and 96 h. The effects of Cd were evaluated through the analysis of ions (Na+, K+, Ca2+, and Cl−) and plasma osmolality, and by measuring the activities of enzymes involved in osmoregulation obtained from the gills and kidney. Fish exposed to Cd for 24 and 96 h showed a decrease in Na+/K+-ATPase activity in the gills and kidney. The activity of carbonic anhydrase decreased in the gills after 24 h and in both tissues after 96 h of Cd exposure. The gill Ca2+-ATPase activity also decreased with Cd exposure, with a concomitant drop in the plasma concentration of Ca2+. Despite the hypocalcemia, there were no changes in the concentration of the ions Na+, K+, and Cl− or in plasma osmolality. Among the enzymes involved in ion transport, H+-ATPase was the only enzyme that showed increased activity in gills, whereas its activity in kidney remained unchanged. The results of this study demonstrate that waterborne Cd at the maximum concentrations set by Brazilian guidelines for freshwater affects the gills and kidney functions of P. lineatus. Acute exposure to Cd resulted in the decrease of

  2. Acute effects of cadmium on osmoregulation of the freshwater teleost Prochilodus lineatus: Enzymes activity and plasma ions

    Silva, Alexandre O.F. da [Departamento de Ciências Fisiológicas, Laboratório de Ecofisiologia Animal, UEL, Londrina (Brazil); Programa Multicêntrico de Pós-graduação em Ciências Fisiológicas, UEL, Londrina (Brazil); Centro de Ciências Humanas e da Educação, UENP, Jacarezinho (Brazil); Martinez, Cláudia B.R., E-mail: cbueno@uel.br [Departamento de Ciências Fisiológicas, Laboratório de Ecofisiologia Animal, UEL, Londrina (Brazil); Programa Multicêntrico de Pós-graduação em Ciências Fisiológicas, UEL, Londrina (Brazil)

    2014-11-15

    Highlights: • Cd effects were evaluated on plasma ions and ATPases of Prochilodus lineatus. • Fish were exposed to 1 and 10 μg Cd L{sup −1} for 24 and 96 h. • Na{sup +}/K{sup +}-ATPase and carbonic anhydrase decreased in gills and kidney after Cd exposure. • Gill Ca{sup 2+}-ATPase and plasma Ca{sup 2+} decreased after Cd exposure. • Cd concentrations set by Brazilian guidelines affect Ca{sup 2+} regulation of P. lineatus. - Abstract: Cadmium (Cd) is a trace element that is very toxic to fish. It is commonly found in surface waters contaminated with industrial effluents. When dissolved in water, Cd can rapidly cause physiological changes in the gills and kidneys of freshwater fish. The objective of this study was to evaluate the acute effects of Cd on the osmoregulation of the Neotropical fish Prochilodus lineatus. Juvenile fish were exposed to Cd at two concentrations [1 (Cd1) and 10 (Cd10) μg L{sup −1}] for 24 and 96 h. The effects of Cd were evaluated through the analysis of ions (Na{sup +}, K{sup +}, Ca{sup 2+}, and Cl{sup −}) and plasma osmolality, and by measuring the activities of enzymes involved in osmoregulation obtained from the gills and kidney. Fish exposed to Cd for 24 and 96 h showed a decrease in Na{sup +}/K{sup +}-ATPase activity in the gills and kidney. The activity of carbonic anhydrase decreased in the gills after 24 h and in both tissues after 96 h of Cd exposure. The gill Ca{sup 2+}-ATPase activity also decreased with Cd exposure, with a concomitant drop in the plasma concentration of Ca{sup 2+}. Despite the hypocalcemia, there were no changes in the concentration of the ions Na{sup +}, K{sup +}, and Cl{sup −} or in plasma osmolality. Among the enzymes involved in ion transport, H{sup +}-ATPase was the only enzyme that showed increased activity in gills, whereas its activity in kidney remained unchanged. The results of this study demonstrate that waterborne Cd at the maximum concentrations set by Brazilian guidelines for

  3. Acute toxicity of cadmium, lead, zinc, and their mixtures to stream-resident fish and invertebrates.

    Mebane, Christopher A; Dillon, Frank S; Hennessy, Daniel P

    2012-06-01

    The authors conducted 150 tests of the acute toxicity of resident fish and invertebrates to Cd, Pb, and Zn, separately and in mixtures, in waters from the South Fork Coeur d'Alene River watershed, Idaho, USA. Field-collected shorthead sculpin (Cottus confusus), westslope cutthroat trout (Oncorhynchus clarkii lewisi), two mayflies (Baetis tricaudatus and Rhithrogena sp.), a stonefly (Sweltsa sp.), a caddisfly (Arctopsyche sp.), a snail (Gyraulus sp.), and hatchery rainbow trout (Oncorhynchus mykiss), were tested with all three metals. With Pb, the mayflies (Drunella sp., Epeorus sp., and Leptophlebiidae), a Simuliidae black fly, a Chironomidae midge, a Tipula sp. crane fly, a Dytiscidae beetle, and another snail (Physa sp.), were also tested. Adult westslope cutthroat trout were captured to establish a broodstock to provide fry of known ages for testing. With Cd, the range of 96-h median effect concentrations (EC50s) was 0.4 to >5,329 µg/L, and the relative resistances of taxa were westslope cutthroat trout ≈ rainbow trout ≈ sculpin trout trout trout trout ≈ sculpin trout fry, a pattern of decreasing resistance with increasing fish size was observed. In metal mixtures, the toxicities of the three metals were less than additive on a concentration-addition basis. PMID:22488500

  4. Biochemical biomarker responses of green-lipped mussel, Perna canaliculus, to acute and subchronic waterborne cadmium toxicity

    Chandurvelan, Rathishri, E-mail: rch118@uclive.ac.nz [School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand); Marsden, Islay D., E-mail: islay.marsden@canterbury.ac.nz [School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand); Gaw, Sally, E-mail: sally.gaw@canterbury.ac.nz [Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand); Glover, Chris N., E-mail: chris.glover@canterbury.ac.nz [School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand)

    2013-09-15

    Highlights: •Biochemical biomarkers were measured to assess effects of Cd on Perna canaliculus. •Biochemical responses varied between acute and subchronic exposure to Cd. •MTLP induction correlated strongly with Cd accumulation. •Alkaline phosphatase and glycogen levels decreased during subchronic Cd exposure. •Duration of Cd exposure influenced biochemical biomarker responses in mussels. -- Abstract: The biochemical responses of the green-lipped mussel, Perna canaliculus, to waterborne cadmium (Cd) were investigated in order to delineate toxic mechanisms, and the impacts of exposure dose and duration, of this important toxicant in a potential sentinel species. Mussels were exposed for either 96 h (acute: 0, 2000, 4000 μg L{sup −1} Cd) or for 28 d (subchronic: 0, 200, 2000 μg L{sup −1} Cd), and the digestive gland, gill and haemolymph were examined for impacts. Biochemical responses measured included those associated with metal detoxification (metallothionein-like protein; MTLP), oxidative stress (catalase, lipid peroxidation), cellular homeostasis (alkaline phosphatase, Na{sup +}, K{sup +}-ATPase; NKA), and energy utilisation (glycogen, haemolymph protein). Following acute exposure, digestive gland glycogen and gill NKA activity were significantly altered by Cd exposure relative to levels in mussels exposed to Cd-free seawater. Subchronic Cd exposure resulted in a significant increase in MTLP levels in both the gill and the digestive gland. This increase was correlated strongly with the levels of Cd accumulation measured in these tissues (R = 0.957 for gill, 0.964 for digestive gland). Catalase activity followed a similar pattern, although the correlation with tissue Cd accumulation was not as strong (R = 0.907 for gill, 0.708 for digestive gland) as that for MTLP. Lipid peroxidation increased in the digestive gland at Days 7 and 14 at both subchronic Cd levels tested, but this effect had largely dissipated by Days 21 and 28 (with the exception of

  5. Biochemical biomarker responses of green-lipped mussel, Perna canaliculus, to acute and subchronic waterborne cadmium toxicity

    Highlights: •Biochemical biomarkers were measured to assess effects of Cd on Perna canaliculus. •Biochemical responses varied between acute and subchronic exposure to Cd. •MTLP induction correlated strongly with Cd accumulation. •Alkaline phosphatase and glycogen levels decreased during subchronic Cd exposure. •Duration of Cd exposure influenced biochemical biomarker responses in mussels. -- Abstract: The biochemical responses of the green-lipped mussel, Perna canaliculus, to waterborne cadmium (Cd) were investigated in order to delineate toxic mechanisms, and the impacts of exposure dose and duration, of this important toxicant in a potential sentinel species. Mussels were exposed for either 96 h (acute: 0, 2000, 4000 μg L−1 Cd) or for 28 d (subchronic: 0, 200, 2000 μg L−1 Cd), and the digestive gland, gill and haemolymph were examined for impacts. Biochemical responses measured included those associated with metal detoxification (metallothionein-like protein; MTLP), oxidative stress (catalase, lipid peroxidation), cellular homeostasis (alkaline phosphatase, Na+, K+-ATPase; NKA), and energy utilisation (glycogen, haemolymph protein). Following acute exposure, digestive gland glycogen and gill NKA activity were significantly altered by Cd exposure relative to levels in mussels exposed to Cd-free seawater. Subchronic Cd exposure resulted in a significant increase in MTLP levels in both the gill and the digestive gland. This increase was correlated strongly with the levels of Cd accumulation measured in these tissues (R = 0.957 for gill, 0.964 for digestive gland). Catalase activity followed a similar pattern, although the correlation with tissue Cd accumulation was not as strong (R = 0.907 for gill, 0.708 for digestive gland) as that for MTLP. Lipid peroxidation increased in the digestive gland at Days 7 and 14 at both subchronic Cd levels tested, but this effect had largely dissipated by Days 21 and 28 (with the exception of the 2000 μg L−1 group

  6. Bronchial reactions to exposure to welding fumes.

    Contreras, G R; Chan-Yeung, M.

    1997-01-01

    OBJECTIVES: To study the airway response and its mechanism to welding fumes in six welders with respiratory symptoms. METHODS: Methacholine and welding challenge tests were carried out. The concentration of welding fumes during the exposure test was measured. On two subjects who developed bronchoconstricition to welding challenge, additional tests were carried out including prick, patch, and inhalation challenges with metal salt solutions. RESULTS: Three subjects developed immediate bronchial...

  7. Influence of Silica Fume on Normal Concrete

    Debabrata Pradhan

    2013-01-01

    The incorporation of silica fume into the normal concrete is a routine one in the present days to produce the tailor made high strength and high performance concrete. The design parameters are increasing with the incorporation of silica fume in conventional concrete and the mix proportioning is becoming complex. The main objective of this paper has been made to investigate the different mechanical properties like compressive strength, compacting factor, slump of concrete incorporating silica ...

  8. Identification of carcinogens in cooking oil fumes.

    Chiang, T A; Wu, P F; Ko, Y C

    1999-07-01

    According to earlier studies, fumes from cooking oils were found to be genotoxic in several short-term tests such as the Ames test, sister chromatid exchange, and SOS chromotest. Fume samples from six different commercial cooking oils (safflower, olive, coconut, mustard, vegetable, and corn) frequently used in Taiwan were collected. Polycyclic aromatic hydrocarbons (PAHs) were extracted from the air samples and identified by high-performance liquid chromatography and confirmed by gas chromatography/mass spectrometry. Extracts of fumes from safflower oil, vegetable oil, and corn oil contained benzo[a]pyrene (BaP), dibenz[a,h]anthracene (DBahA), benzo[b]fluoranthene (BbFA), and benzo[a]anthracene (BaA). Concentrations of BaP, DbahA, BbFA, and BaA were 2.1, 2.8, 1.8, and 2.5 microg/m3 in fumes from safflower oil; 2.7, 3.2, 2.6, and 2.1 microg/m3 in vegetable oil; and 2.6, 2.4, 2.0, and 1.9 microg/m3 in corn oil, respectively. The authors constructed models to study the efficacy of table-edged fume extractors used commonly by Taiwanese restaurants. Concentrations of BaP were significantly decreased when the fume extractor was working (Pextractors near cooking pots. PMID:10361022

  9. WOOD COLOR CHANGES BY AMMONIA FUMING

    Josip Miklečić,

    2012-06-01

    Full Text Available This paper studies the influence of ammonia gas on wood color changes in response to an increasing demand for dark colored wood specimens. The darker wood color in ammonia fuming is accomplished through chemical reactions between ammonia gas and wood compounds. We exposed oak, maple, spruce, and larch wood samples to ammonia gas for 16 days. During fuming, the color changes were studied using CIE L*a*b* parameters. After fuming, the changes in extractives content, tannin, and nitrogen content were analyzed. The chemical changes of wood and residues of wood extractives after fuming were analyzed by FTIR spectroscopy. Oak wood reacted intensively with ammonia gas in a very short time, and the darkening was prominent for all the investigated wood species. It was established that tannin had no major influence on color changes of maple and larch wood in the ammonia-fuming process. The FTIR spectra of fumed wood indicated involvement of carbonyl groups, and the FTIR spectra of wood extractives indicated involvement of carbonyl, aromatic, and alcohol groups in reaction with ammonia gas.

  10. Influence of Silica Fume on Normal Concrete

    Debabrata Pradhan

    2013-09-01

    Full Text Available The incorporation of silica fume into the normal concrete is a routine one in the present days to produce the tailor made high strength and high performance concrete. The design parameters are increasing with the incorporation of silica fume in conventional concrete and the mix proportioning is becoming complex. The main objective of this paper has been made to investigate the different mechanical properties like compressive strength, compacting factor, slump of concrete incorporating silica fume. In this present paper 5 (five mix of concrete incorporating silica fume are cast to perform experiments. These experiments were carried out by replacing cement with different percentages of silica fume at a single constant water-cementitious materials ratio keeping other mix design variables constant. The silica fume was replaced by 0%, 5%, 10%, 15% and 20% for water-cementitious materials (w/cm ratio for 0.40. For all mixes compressive strengths were determined at 24 hours, 7 and 28 days for 100 mm and 150 mm cubes. Other properties like compacting factor and slump were also determined for five mixes of concrete.

  11. Acute and chronic sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to cadmium, copper, lead, or zinc in laboratory water-only exposures

    Ingersoll, Christopher G.; Contributions by Wang, Ning; Calfee, Robin D.; Beahan, Erinn; Brumbaugh, William G.; Dorman, Rebecca A.; Hardesty, Doug K.; Kunz, James L.; Little, Edward E.; Mebane, Christopher A.; Puglis, Holly J.

    2014-01-01

    White sturgeon (Acipenser transmontanus) are experiencing poor recruitment in the trans boundary reach of the upper Columbia River in eastern Washington State. Limited toxicity data indicated that early life stages of white sturgeon are sensitive to metals. In acute 4-day (d) exposures with larval white sturgeon, previous studies have reported that the 4-day median lethal concentrations (LC50) based on biotic ligand model (BLM) normalization for copper were below the U.S. Environmental Protection Agency national recommended acute water-quality criterion. In previously published chronic 66-d exposures starting with newly fertilized eggs of white sturgeon, 20-percent lethal effect concentrations (LC20s) for copper, cadmium, or zinc generally were within a factor of two of the chronic values of the most sensitive fish species in the databases of the U.S. Environmental Protection Agency water-quality criteria (WQC) for the three metals. However, there were some uncertainties in the chronic exposures previously performed with white sturgeon, including (1) low control survival (37 percent), (2) more control fish tested in each replicate compared to other treatments, (3) limited replication of treatments (n=2), (4) lack of reported growth data (such as dry weight), and (5) wide dilution factors for exposure concentrations (6- to 8-fold dilutions). The U.S. Environmental Protection Agency concluded that additional studies are needed to generate more toxicity data to better define lethal and sublethal toxicity thresholds for metals for white sturgeon. The objective of the study was to further evaluate the acute and chronic toxicity of cadmium, copper, lead, or zinc to early life stages of white sturgeon in water-only exposures. Toxicity tests also were performed with commonly tested rainbow trout (Oncorhynchus mykiss) under similar test conditions to determine the relative sensitivity between white sturgeon and rainbow trout to these metals. Toxicity data generated from

  12. Oral cadmium chloride intoxication in mice

    Andersen, O; Nielsen, J B; Svendsen, P

    1988-01-01

    Diethyldithiocarbamate (DDC) is known to alleviate acute toxicity due to injection of cadmium salts. However, when cadmium chloride was administered by the oral route, DDC enhanced rather than alleviated the acute toxicity; both oral and intraperitoneal (i.p.) administration of DDC had this effec...

  13. Response of the mouse lung transcriptome to welding fume: effects of stainless and mild steel fumes on lung gene expression in A/J and C57BL/6J mice

    Antonini James M

    2010-06-01

    Full Text Available Abstract Background Debate exists as to whether welding fume is carcinogenic, but epidemiological evidence suggests that welders are an at risk population for the development of lung cancer. Recently, we found that exposure to welding fume caused an acutely greater and prolonged lung inflammatory response in lung tumor susceptible A/J versus resistant C57BL/6J (B6 mice and a trend for increased tumor incidence after stainless steel (SS fume exposure. Here, our objective was to examine potential strain-dependent differences in the regulation and resolution of the lung inflammatory response induced by carcinogenic (Cr and Ni abundant or non-carcinogenic (iron abundant metal-containing welding fumes at the transcriptome level. Methods Mice were exposed four times by pharyngeal aspiration to 5 mg/kg iron abundant gas metal arc-mild steel (GMA-MS, Cr and Ni abundant GMA-SS fume or vehicle and were euthanized 4 and 16 weeks after the last exposure. Whole lung microarray using Illumina Mouse Ref-8 expression beadchips was done. Results Overall, we found that tumor susceptibility was associated with a more marked transcriptional response to both GMA-MS and -SS welding fumes. Also, Ingenuity Pathway Analysis revealed that gene regulation and expression in the top molecular networks differed between the strains at both time points post-exposure. Interestingly, a common finding between the strains was that GMA-MS fume exposure altered behavioral gene networks. In contrast, GMA-SS fume exposure chronically upregulated chemotactic and immunomodulatory genes such as CCL3, CCL4, CXCL2, and MMP12 in the A/J strain. In the GMA-SS-exposed B6 mouse, genes that initially downregulated cellular movement, hematological system development/function and immune response were involved at both time points post-exposure. However, at 16 weeks, a transcriptional switch to an upregulation for neutrophil chemotactic genes was found and included genes such as S100A8, S100A9 and

  14. Expression of apoptotic nuclei by ultrastructural terminal deoxyribonucleotidyl transferase mediated dUTP nick end labeling and detection of FasL, caspases and PARP protein molecules in cadmium induced acute alveolar cell injury

    Cadmium causes cellular damage but the exact mechanism of apoptosis in cadmium induced acute lung injury is not clear. We investigated the sequential expression of apoptotic nuclei and detected related molecules in tissue of cadmium-induced acute lung injury. Forty Sprague-Dawley rats were sacrificed at days 1, 3, 7 and 10 after intra-tracheal cadmium injection (2.5 mg/kg). Light microscopic, ultrastructural terminal deoxyribonucleotidyl transferase mediated dUTP nick end labeling (TUNEL), and Western blot analysis for detection of FasL, Bid, cytochrome c, caspase 3 and PARP were carried out. Apoptosis occurred at day 1, and markedly decreased at days 3, 7 and 10 (11.8, 2.8, 0.9, 0.5%, respectively) determined by light microscopy and TUNEL assay. Ultrastructural TUNEL revealed two patterns of nuclear morphology according to the apoptotic stage. One pattern showed chromatin fragmentation and apoptotic nuclear body formation. The other pattern had bleb formation in the chromatin, budding with projection out to the nuclear membranes, fragmentation, segregation of chromatin clumps and apoptotic body formation. Western blot analysis showed prominent expression of FasL at days 1 and 3. Expression of Bid, cytochrome c and caspase 3 were prominent at day 1 compared to days 3, 7 and 10. PARP cleavage was prominent at day 1. In conclusion, intra-tracheal cadmium injection showed active alveolar cell apoptosis at day 1. Ultrastructural TUNEL showed various expressions according to the apoptotic nuclear stage. These studies suggest that cadmium-induced alveolar cell apoptosis is mediated by FasL and caspase-dependent mitochondrial apoptosis pathways

  15. MIXING PHENOMENA IN INDUSTRIAL FUME AFTERBURNER SYSTEMS

    The report reviews the physical-mixing phenomena involved in the reactions that occur in afterburners or fume incinerators. It considers mixing in after-burners from three points of view. It first covers typical designs of afterburner components that are involved in the mixing ph...

  16. Cadmium carcinogenesis

    Waalkes, Michael P

    2003-12-10

    Cadmium is a heavy metal of considerable environmental and occupational concern. Cadmium compounds are classified as human carcinogens by several regulatory agencies. The most convincing data that cadmium is carcinogenic in humans comes from studies indicating occupational cadmium exposure is associated with lung cancer. Cadmium exposure has also been linked to human prostate and renal cancer, although this linkage is weaker than for lung cancer. Other target sites of cadmium carcinogenesis in humans, such as liver, pancreas and stomach, are considered equivocal. In animals, cadmium effectively induces cancers at multiple sites and by various routes. Cadmium inhalation in rats induces pulmonary adenocarcinomas, in accord with its role in human lung cancer. Cadmium can induce tumors and/or preneoplastic lesions within the rat prostate after ingestion or injection. At relatively high doses, cadmium induces benign testicular tumors in rats, but these appear to be due to early toxic lesions and loss of testicular function, rather than from a specific carcinogenic effect of cadmium. Like many other metals, cadmium salts will induce mesenchymal tumors at the site of subcutaneous (s.c.) or intramuscular (i.m.) injections, but the human relevance of these is dubious. Other targets of cadmium in rodents include the liver, adrenal, pancreas, pituitary, and hematopoietic system. With the exception of testicular tumors in rodents, the mechanisms of cadmium carcinogenesis are poorly defined. Cadmium can cause any number of molecular lesions that would be relevant to oncogenesis in various cellular model systems. Most studies indicate cadmium is poorly mutagenic and probably acts through indirect or epigenetic mechanisms, potentially including aberrant activation of oncogenes and suppression of apoptosis.

  17. Cadmium carcinogenesis

    Cadmium is a heavy metal of considerable environmental and occupational concern. Cadmium compounds are classified as human carcinogens by several regulatory agencies. The most convincing data that cadmium is carcinogenic in humans comes from studies indicating occupational cadmium exposure is associated with lung cancer. Cadmium exposure has also been linked to human prostate and renal cancer, although this linkage is weaker than for lung cancer. Other target sites of cadmium carcinogenesis in humans, such as liver, pancreas and stomach, are considered equivocal. In animals, cadmium effectively induces cancers at multiple sites and by various routes. Cadmium inhalation in rats induces pulmonary adenocarcinomas, in accord with its role in human lung cancer. Cadmium can induce tumors and/or preneoplastic lesions within the rat prostate after ingestion or injection. At relatively high doses, cadmium induces benign testicular tumors in rats, but these appear to be due to early toxic lesions and loss of testicular function, rather than from a specific carcinogenic effect of cadmium. Like many other metals, cadmium salts will induce mesenchymal tumors at the site of subcutaneous (s.c.) or intramuscular (i.m.) injections, but the human relevance of these is dubious. Other targets of cadmium in rodents include the liver, adrenal, pancreas, pituitary, and hematopoietic system. With the exception of testicular tumors in rodents, the mechanisms of cadmium carcinogenesis are poorly defined. Cadmium can cause any number of molecular lesions that would be relevant to oncogenesis in various cellular model systems. Most studies indicate cadmium is poorly mutagenic and probably acts through indirect or epigenetic mechanisms, potentially including aberrant activation of oncogenes and suppression of apoptosis

  18. Characterisation of fume from hyperbaric welding operations

    We report preliminary work characterising dust from hyperbaric welding trials carried out at increased pressure in a helium and oxygen atmosphere. Particle size and concentration were measured during welding. Samples for quartz and metal analysis and toxicity assessment were taken from a filter in the local fume extraction system. The residue of dust after metal extraction by nitric acid in hydrogen peroxide predominantly a non-metallic white powder assumed to be dust from welding rod coatings and thermal insulation material. Metallic analysis showed predominantly calcium, from the welding rod coating, and period 4 transition metals such as iron, manganese, magnesium and titanium (inductively coupled mass spectrometry, Agilent 7500c). The presence of zirconium indicated a contribution from grinding. The fume was nanoparticulate in nature with a mean particle diameter of 20-30 nm (MSI Inc WPS 1000XP). It showed an intermediate level of oxidative potential regarding the low-molecular weight respiratory tract lining fluid antioxidants ascorbate and glutathione and caused release of the inflammatory marker IL-8 in a human lung A 549 epithelial cell culture with no indication of cytotoxicity. The study findings have strong implications for the measurement techniques needed to assess fume exposure in hyperbaric welding and the provision of respiratory protection.

  19. Acute sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to copper, cadmium, or zinc in water-only laboratory exposures

    Calfee, Robin D.; Little, Edward E.; Puglis, Holly J.; Scott, Erinn L.; Brumbaugh, William G.; Mebane, Christopher A.

    2014-01-01

    The acute toxicity of cadmium, copper, and zinc to white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) were determined for 7 developmental life stages in flow-through water-only exposures. Metal toxicity varied by species and by life stage. Rainbow trout were more sensitive to cadmium than white sturgeon across all life stages, with median effect concentrations (hardness-normalized EC50s) ranging from 1.47 µg Cd/L to 2.62 µg Cd/L with sensitivity remaining consistent during later stages of development. Rainbow trout at 46 d posthatch (dph) ranked at the 2nd percentile of a compiled database for Cd species sensitivity distribution with an EC50 of 1.46 µg Cd/L and 72 dph sturgeon ranked at the 19th percentile (EC50 of 3.02 µg Cd/L). White sturgeon were more sensitive to copper than rainbow trout in 5 of the 7 life stages tested with biotic ligand model (BLM)-normalized EC50s ranging from 1.51 µg Cu/L to 21.9 µg Cu/L. In turn, rainbow trout at 74 dph and 95 dph were more sensitive to copper than white sturgeon at 72 dph and 89 dph, indicating sturgeon become more tolerant in older life stages, whereas older trout become more sensitive to copper exposure. White sturgeon at 2 dph, 16 dph, and 30 dph ranked in the lower percentiles of a compiled database for copper species sensitivity distribution, ranking at the 3rd (2 dph), 5th (16 dph), and 10th (30 dph) percentiles. White sturgeon were more sensitive to zinc than rainbow trout for 1 out of 7 life stages tested (2 dph with an biotic ligand model–normalized EC50 of 209 µg Zn/L) and ranked in the 1st percentile of a compiled database for zinc species sensitivity distribution.

  20. Reaction Degree of Silica Fume and Its Effect on Compressive Strength of Cement-silica Fume Blends

    WANG Xiaojun; PAN Zhigang; ZHU Chengfei; ZHU Hongfei

    2014-01-01

    The compressive strength of the cement-silica fume blends with 5mass%, 10mass%, 20mass%and 30mass%of silica fume and water to binder ratio of 0.28, 0.32 and 0.36 from three days to ninety days were investigated. The reaction degree of silica fume was calculated from the Q4 silica tetrahedron, which was used as a probe obtained from 29Si solid state nuclear magnetic resonance analysis. The flat of compressive strength after 28 days disappeared for blended cement with inereasing reaction degree of silica fume. The compressive strength of the blended cement pastes approached that of P.I. cement pastes after 56 days and exceeded that after 90 days. The addition of silica fume and the w/b ratio of blends are both critical to the reaction degree of silica fume. The appropriate addition of silica fume, high silica fume reaction degree and low w/b ratio are beneficial to the compressive strength of the cement-silica fume blends.

  1. Effects of diethyldithiocarbamate on the toxicokinetics of cadmium chloride in mice

    Andersen, O; Nielsen, J B

    1989-01-01

    investigates effects of DDC on the toxicokinetics of cadmium at lower doses of cadmium than those used in previous studies. During single exposure to subtoxic oral doses of cadmium chloride DDC enhanced intestinal cadmium absorption, both after intraperitoneal and oral administration of DDC. In such acute...

  2. Neutron inelastic scattering from fumed silica

    Neutron inelastic scattering measurement have been performed on samples of fumed silica ('Cab-O-Sil') as a function of energy, momentum-transfer vector Q, and temperature T, and compared with analogous results for amorphous quartz. No evidence seen for a sharp crossover in the vibrational density of states of Cab-O-Sil between phonon and fracton regimes, but the inelastic scattering shows anomalous behavior in several respects. Neither the T dependence nor the Q dependence nor the absolute intensity of the scattering from Cab-O-Sil is in accord with simple phonon models. (author)

  3. High effective silica fume alkali activator

    Vladimír Živica

    2004-04-01

    Growing demands on the engineering properties of cement based materials and the urgency to decrease unsuitable ecologic impact of Portland cement manufacturing represent significant motivation for the development of new cement corresponding to these aspects. One category represents prospective alkali activated cements. A significant factor influencing their properties is alkali activator used. In this paper we present a new high effective alkali activator prepared from silica fume and its effectiveness. According to the results obtained this activator seems to be more effective than currently used activators like natrium hydroxide, natrium carbonate, and water glass.

  4. Study of radon transport through concrete modified with silica fume

    The concentration of radon in soil usually varies between a few kBq/m3 and tens or hundreds of kBq/m3 depending upon the geographical region. This causes the transport of radon from the soil to indoor environments by diffusion and advection through the pore space of concrete. To reduce indoor radon levels, the use of concrete with low porosity and a low radon diffusion coefficient is recommended. A method of reducing the radon diffusion coefficient through concrete and hence the indoor radon concentration by using silica fume to replace an optimum level of cement was studied. The diffusion coefficient of the concrete was reduced from (1.63 ± 0.3) × 10−7 to (0.65 ± 0.01) × 10−8 m2/s using 30% substitution of cement with silica fume. The compressive strength of the concrete increased as the silica-fume content increased, while radon exhalation rate and porosity of the concrete decreased. This study suggests a cost-effective method of reducing indoor radon levels. -- Highlights: • Radon diffusion study through silica fume modified concrete was carried out. • Radon diffusion coefficient of concrete decreased with increase of silica fume contents. • Compressive strength increased with increase of silica fume. • Radon exhalation rates and porosity of samples decreased with addition of silica fume. • Radon diffusion coefficient decreased to 2.6% by 30% silica fume substitution

  5. Bitumen fume-induced gene expression profile in rat lung

    Exposure to bitumen fumes during paving and roofing activities may represent an occupational health risk. To date, most of the studies performed on the biological effect of asphalt fumes have been done with regard to their content in carcinogenic polycyclic aromatic hydrocarbons (PAH). In order to gain an additional insight into the mechanisms of action of bitumen fumes, we studied their pulmonary effects in rodents following inhalation using the microarray technology. Fisher 344 rats were exposed for 5 days, 6 h/day to bitumen fumes generated at road paving temperature (170 oC) using a nose-only exposition device. With the intention of studying the early transcriptional events induced by asphalt fumes, lung tissues were collected immediately following exposure and gene expression profiles in control and exposed rats were determined by using oligonucleotide microarrays. Data analysis revealed that genes involved in lung inflammatory response as well as genes associated with PAH metabolization and detoxification were highly expressed in bitumen-exposed animals. In addition, the expression of genes related to elastase activity and its inhibition which are associated with emphysema was also modulated. More interestingly genes coding for monoamine oxidases A and B involved in the metabolism of neurotransmitters and xenobiotics were downregulated in exposed rats. Altogether, these data give additional information concerning the bitumen fumes biological effects and would allow to better review the health effects of occupational asphalt fumes exposure

  6. Immunotoxicology of arc welding fume: worker and experimental animal studies.

    Zeidler-Erdely, Patti C; Erdely, Aaron; Antonini, James M

    2012-01-01

    Arc welding processes generate complex aerosols composed of potentially hazardous metal fumes and gases. Millions of workers worldwide are exposed to welding aerosols daily. A health effect of welding that is of concern to the occupational health community is the development of immune system dysfunction. Increased severity, frequency, and duration of upper and lower respiratory tract infections have been reported among welders. Specifically, multiple studies have observed an excess mortality from pneumonia in welders and workers exposed to metal fumes. Although several welder cohort and experimental animal studies investigating the adverse effects of welding fume exposure on immune function have been performed, the potential mechanisms responsible for these effects are limited. The objective of this report was to review both human and animal studies that have examined the effect of welding fume pulmonary exposure on local and systemic immune responses. PMID:22734811

  7. When are fume-cupboards necessary in hospital radioisotope laboratories

    Suggestions are made for procedures likely to require the provision of efficient fume-cupboards in hospital radioisotope laboratories. All such departments undertaking in vivo radioisotope procedures will require a supply of sterile materials, but only some of these will also require a fume-cupboard, since the use of a relatively inexpensive aseptic cabinet, without air flow and exhaust system, may suffice for such procedures as the labelling of blood cells or plasma. Efficient fume-cupboards may be required in hospital laboratories that are routinely concerned with the elution of generators of isotopes such as 99Tcsup(m) and 113Insup(m), the sterilization of radiopharmaceuticals (e.g. technetium-sulphur colloid) requiring the use of a pressure cooker, and the storage and handling of therapeutic quantities of 131I. Copious general ventilation of isotope rooms may be preferable to the too frequent incorporation of unnecessary fume-cupboards. (U.K.)

  8. Decreasing biotoxicity of fume particles produced in welding process

    Welding fumes contain heavy metals, such as chromium, manganese, and nickel, which cause respiratory diseases and cancer. In this study, a SiO2 precursor was evaluated as an additive to the shielding gas in an arc welding process to reduce the biotoxicity caused by welding fume particles. Transmission electron micrographic images show that SiO2 coats on the surface of welding fume particles and promotes particle agglomeration. Energy dispersive X-ray spectroscopy further shows that the relative amount of silicon in these SiO2-coated agglomerates is higher than in baseline agglomerates. In addition, Escherichia coli (E. coli) exposed to different concentrations of pure SiO2 particles generated from the arc welding process exhibits similar responses, suggesting that SiO2 does not contribute to welding fume particle toxicity. The trend of E. coli growth in different concentrations of baseline welding fume particle shows the most significant inhibition occurs in higher exposure concentrations. The 50% lethal logarithmic concentrations for E. coli in arc welding particles of baseline, 2%, and 4.2% SiO2 precursor additives were 823, 1605, and 1800 mg/L, respectively. Taken together, these results suggest that using SiO2 precursors as an additive to arc welding shielding gas can effectively reduce the biotoxicity of welding fume.

  9. Influence of long-term cadmium and selenite exposure on resistance to Listeria monocytogenes during acute and chronic infection in mice

    Šimonytė, Sandrita; Plančiūnienė, Rita; Cherkashin, Gennadij; žekonis, Gediminas

    2006-01-01

    The aim of the present study was to evaluate the effect of long-term exposure to cadmium and selenite ions on the BALB/c mice resistance to experimental Listeria monocytogenes infection. A low-dose six-week exposure to cadmium ions (10 mg/ l in drinking water) decreased the clearance of listeria from mice liver and spleen at 24 h in the early phase of infection. Long-term treatment of mouse with selenite ions (0.15 mg/l) did not activate the elimination of bacteria from the organs. Eight week...

  10. Interaction of poly(ethylene oxide) with fumed silica.

    Voronin, E F; Gun'ko, V M; Guzenko, N V; Pakhlov, E M; Nosach, L V; Leboda, R; Skubiszewska-Zieba, J; Malysheva, M L; Borysenko, M V; Chuiko, A A

    2004-11-15

    Interaction of poly(ethylene oxide) (PEO, 600 kDa) with fumed silica A-300 (SBET = 316 m2/g) was investigated under different conditions using adsorption, infrared (IR), thermal analysis (TG-DTA), AFM, and quantum chemical methods. The studied dried silica/PEO samples were also carbonized in a flow reactor at 773 K. The structural characteristics of fumed silica, PEO/silica, and pyrocarbon/fumed silica were investigated using nitrogen adsorption-desorption at 77.4 K. PEO adsorption isotherm depicts a high affinity of PEO to the fumed silica surface in aqueous medium. PEO adsorbed in the amount of 50 mg per gram of silica (PEO monolayer corresponds to CPEO approximately 190 mg/g) can disturb approximately 70% of isolated surface silanols. However, at the monolayer coverage, only 20% of oxygen atoms of PEO molecules take part in the hydrogen bonding with the surface silanols. An increase in the PEO amount adsorbed on fumed silica leads to a diminution of the specific surface area and contributions of micro- (pore radius R 25 nm) increases with CPEO. Quantum chemical calculations of a complex of a PEO fragment with a tripple bond SiOH group of a silica cluster in the gas phase and with consideration for the solvent (water) effect show a reduction of interaction energy in the aqueous medium. However, the complex remains strong enough to provide durability of the PEO adsorption complexes on fumed silica; i.e., PEO/fumed silica nanocomposites could be stable in both gaseous and liquid media. PMID:15464796

  11. The Nrf2 transcription factor contributes to the induction of alpha-class GST isoenzymes in liver of acute cadmium or manganese intoxicated rats: Comparison with the toxic effect on NAD(P)H:quinone reductase

    In rat liver, in addition to their intrinsic transferase activity, alpha-class GSTs have Se-independent glutathione peroxidase activity toward fatty acid hydroperoxides, cumene hydroperoxide and phospholipids hydroperoxides but not toward H2O2. We have previously shown that hepatic GST activity by these isoenzymes is significantly increased 24 h after cadmium or manganese administration (). Here it is reported that Se-independent glutathione peroxidase activity by alpha-class GSTs is also stimulated in the liver of intoxicated rats. The stimulation is associated with a higher level of alpha-class GST proteins, whose induction is blocked by actinomycin D co-administration. The observed Se-independent glutathione peroxidase activity is due to alpha-class GST isoenzymes, as indicated by the studies with diethyldithiocarbamate which, at any concentration, equally inhibits both GST and Se-independent glutathione peroxidase and is an uncompetitive inhibitor of both enzymes. As for liver Se-GSPx, it is not at all affected under these toxic conditions. For comparison, we have evaluated the status of another important antioxidant enzyme, NAD(P)H:quinone reductase, 24 h after cadmium or manganese administration. NQO1 too results strongly stimulated in the liver of the intoxicated rats. In these animals, a higher expression of Nrf2 protein is observed, actively translocated from the cytoplasm to the nucleus. The results with the transcription inhibitor, actinomycin D, and the effects on Nrf2 protein are the first clear indication that acute manganese intoxication, similarly to that of cadmium and other heavy metals, increases both the hepatic level of Nrf2 and its transfer from the cytoplasm to the nucleus where it actively regulates the induction of phase II enzymes

  12. Environmental exposure to cooking oil fumes and cervical intraepithelial neoplasm

    The fumes from cooking oil, similar to cigarette smoke, contain numerous carcinogens such as polycyclic aromatic hydrocarbons, aromatic amines, nitro-polycyclic aromatic hydrocarbons, etc. In this study, we examined the association between exposure to cooking oil fumes and the risk of cervical intraepithelial neoplasm. The study population in this nested case-control study consisted of women above the age of 19 years living in Chia-Yi County, located in the southwestern Taiwan, who had received pap smear screening between October, 1999, and December, 2000 (n=32,466). The potential cases were women having lesions greater than cervical intraepithelium neoplasm II (≥CIN2) reconfirmed by cervical biopsy (n=116). The potential controls (case: control=1:2) were age-matched (±2 years) and residence-matched women who had normal pap smears within 6 months of the cases. In total, 100 cases and 197 controls were completely interviewed by public health nurses about cooking methods, ventilation, and other potential risk factors. Women who cooked at home in a kitchen (n=269) without the presence of a fume extractor at least once a week between the ages of 20 and 40 had a 2.29 times higher risk [95% confidence interval (CI)=1.08-4.87] of developing cervical intraepithelial neoplasm than those who did not cook once a week in such a kitchen during the same age span, after adjusting for other potential confounders. This finding was further strengthened by the finding that women who did not use the fume extractors had a 2.47 times higher risk (95% CI=1.15-5.32) of developing cervical intraepithelial neoplasm than women who cooked in kitchens with fume extractors that were always switched on while cooking. We also found a joint protective effect of fume extractor use among women older than 40 years (n=202) if they used the extractors during both age spans of their lives, ages 20-40 and >40 years. Comparing our findings on women more than 40 years old who used fume extractors during

  13. Reactions Involved in Fingerprint Development Using the Cyanoacrylate - Fuming Method

    The Learning Objective is to present the basic chemistry research findings to the forensic community regarding development of latent fingerprints using the cyanoacrylate fuming method. Chemical processes involved in the development of latent fingerprints using the cyanoacrylate fuming method have been studied, and will be presented. Two major types of latent prints have been investigated-clean (eccrine) and oily (sebaceous) prints. Scanning electron microscopy (SEM) was used as a tool for determining the morphology of the polymer developed separately on clean and oily prints after cyanoacrylate fuming. A correlation between the chemical composition of an aged latent fingerprint, prior to development, and the quality of a developed fingerprint was observed in the morphology. The moisture in the print prior to fuming was found to be a critical factor for the development of a useful latent print. In addition, the amount of time required to develop a high quality latent print was found to be minimal. The cyanoacrylate polymerization process is extremely rapid. When heat is used to accelerate the fuming process, typically a period of 2 minutes is required to develop the print. The optimum development time is dependent upon the concentration of cyanoacrylate vapors within the enclosure

  14. Reactions Involved in Fingerprint Development Using the Cyanoacrylate - Fuming Method

    Lewis, L.A.

    2001-07-30

    The Learning Objective is to present the basic chemistry research findings to the forensic community regarding development of latent fingerprints using the cyanoacrylate fuming method. Chemical processes involved in the development of latent fingerprints using the cyanoacrylate fuming method have been studied, and will be presented. Two major types of latent prints have been investigated--clean (eccrine) and oily (sebaceous) prints. Scanning electron microscopy (SEM) was used as a tool for determining the morphology of the polymer developed separately on clean and oily prints after cyanoacrylate fuming. A correlation between the chemical composition of an aged latent fingerprint, prior to development, and the quality of a developed fingerprint was observed in the morphology. The moisture in the print prior to fuming was found to be a critical factor for the development of a useful latent print. In addition, the amount of time required to develop a high quality latent print was found to be minimal. The cyanoacrylate polymerization process is extremely rapid. When heat is used to accelerate the fuming process, typically a period of 2 minutes is required to develop the print. The optimum development time is dependent upon the concentration of cyanoacrylate vapors within the enclosure.

  15. Energy use and savings potential for laboratory fume hoods

    Fume hoods--small but essential safety devices used in laboratory environments--are highly energy-intensive, each one consuming more energy than three homes in an average U.S. climate. Increasing airflow rates in an effort to enhance safety not only elevates energy use but can in fact compromise safety by causing dangerous turbulence that can foil containment. New design strategies have been demonstrated to reduce energy use by 75%, while maintaining or enhancing safety. The energy savings potential for these hoods across the United States is $1.5 billion annually. If incorporated in new laboratory construction, high-performance fume hoods can also yield substantial first-cost savings by allowing downsizing of heating, ventilating, and air-conditioning infrastructure. However, there are material hurdles to widespread adoption of new fume hood technologies. The problems reside in regulations and standards that stipulate absolute airflow rates, rather than direct metrics of containment and safety

  16. Catalytic Disposal of Cooking Fume Discharged from the Restaurant

    2001-01-01

    @@ The cooking oil fume pollution have been becoming a serious problem.1 Though several methods on disposal technology of the fume have been developed at home and abroad, such as filtration process, electrostatic process and wet process, practical and effective technology is still needed.2In the present study, we will report a new disposal process of cooking fume, which were turned complete into water and CO2 in the presence of the catalysts. Catalysts were prepared by the following procedure. First, layer of A12O3 was painted on the inner pore surface of ceramic honeycomb carrier. Second, a solution of platinum and palladium salts in alcohol was used for impregnation in a suitable concentration to obtain a catalyst 0.3% noble metals.

  17. A Study on Genotoxicity of Cooking Fume from Rapessed Oil

    CHENHUA; YANGMINGDING; 等

    1992-01-01

    The present article reports the genotoxic potential of rapeseed oil cooking fume investigated by a battery of short-term tests(Ames test,SCE/V79 in vitor and mice micronucleus in vivo test).The results showed that the cooking fume contained mutagenic activity.In the presence of S9 mix,an increase in the number of the Salmonella TA98 was observed at doses ranging from 1.0 to 5.0mg/plate,and the SCE frequencies of V79 cell were markedly raised at doses ranging from 0.05 to 0.5mg·m-1.The positive result was also obtained in mice micronucleus assay,the mice had inhaled the cooking fume a week earlier.The requency of mice bone marrow MN-PCR ws increased and it showed a remarkable time-dose-response relationship during the 4 weeks exposure.The results suggested that this cooking fume exposure may be a risk factor of lung cancer in Chinese women.

  18. Significance of Silica Fume in Enhancing the Quality of Concrete

    Vipul Thakur

    2013-04-01

    Full Text Available In the Refractories world three decades ago, very few people were acquainted to silica fume and its usage. After a few years, it was used as an additive to brick. When added to high Alumina brick, mullite was formed in the matrix of the brick on firing, giving the brick good volume stability, strength and chemical resistance. When used in basic brick, high hot strengths resulted, at least at 2700oF, which was about the limit of what could be tested. At the time it was only logical that silica fume would be used in brick not castables. Brick were used for all critical applications, no one would have considered using castables. In this paper we shall discuss the manufacturing, properties of silica fume and its effect on concrete after addition. Today’s refractory castables have gone beyond having “brick-like properties” to actually out performing brick in many applications. Silica fume has played a major role in this transformation

  19. Assessment and management of risk to wildlife from cadmium

    Cadmium, a nonessential heavy metal that comes from natural and anthropogenic sources, is a teratogen, carcinogen, and a possible mutagen. Assessment of potential risk from cadmium requires understanding environmental exposure, mainly from ingestion, although there is some local exposure through inhalation. Chronic exposure is more problematic than acute exposure for wildlife. There is evidence for bioaccumulation, particularly in freshwater organisms, but evidence for biomagnification up the food chain is inconsistent; in some bird studies, cadmium levels were higher in species that are higher on the food chain than those that are lower. Some freshwater and marine invertebrates are more adversely affected by cadmium exposure than are birds and mammals. There is very little experimental laboratory research on the effects of cadmium in amphibians, birds and reptiles, and almost no data from studies of wildlife in nature. Managing the risk from cadmium to wildlife involves assessment (including ecological risk assessment), biomonitoring, setting benchmarks of effects, regulations and enforcement, and source reduction

  20. Acute toxicity of copper and cadmium for piauçu, Leporinus macrocephalus, and curimatã, Prochilodus vimboides - DOI: 10.4025/actascibiolsci.v31i3.5069 Acute toxicity of copper and cadmium for piauçu, Leporinus macrocephalus, and curimatã, Prochilodus vimboides - DOI: 10.4025/actascibiolsci.v31i3.5069

    Luis Fernando Loureiro Fernandes

    2009-07-01

    Full Text Available Ninety-six-hour static bioassays were conducted in the laboratory to determine lethal concentrations (96-h LC50 of copper and cadmium for curimatã (Prochilodus vimboides and piauçu (Leporinus macrocephalus. The 96-h LC50 of copper were 0.047 and 0.090 mg L-1, and of cadmium 3.16 and 7.42 mg L-1 for curimatã and piauçu, respectively. Curimatã is a preferred indigenous species for toxicological studies in the Doce River basin due to its availability in the hatcheries of the region and high sensitivity to metals.Ninety-six-hour static bioassays were conducted in the laboratory to determine lethal concentrations (96-h LC50 of copper and cadmium for curimatã (Prochilodus vimboides and piauçu (Leporinus macrocephalus. The 96-h LC50 of copper were 0.047 and 0.090 mg L-1, and of cadmium 3.16 and 7.42 mg L-1 for curimatã and piauçu, respectively. Curimatã is a preferred indigenous species for toxicological studies in the Doce River basin due to its availability in the hatcheries of the region and high sensitivity to metals.

  1. Reduction of Biomechanical and Welding Fume Exposures in Stud Welding.

    Fethke, Nathan B; Peters, Thomas M; Leonard, Stephanie; Metwali, Mahmoud; Mudunkotuwa, Imali A

    2016-04-01

    The welding of shear stud connectors to structural steel in construction requires a prolonged stooped posture that exposes ironworkers to biomechanical and welding fume hazards. In this study, biomechanical and welding fume exposures during stud welding using conventional methods were compared to exposures associated with use of a prototype system that allowed participants to weld from an upright position. The effect of base material (i.e. bare structural beam versus galvanized decking) on welding fume concentration (particle number and mass), particle size distribution, and particle composition was also explored. Thirty participants completed a series of stud welding simulations in a local apprenticeship training facility. Use of the upright system was associated with substantial reductions in trunk inclination and the activity levels of several muscle groups. Inhalable mass concentrations of welding fume (averaged over ~18 min) when using conventional methods were high (18.2 mg m(-3) for bare beam; 65.7 mg m(-3) for through deck), with estimated mass concentrations of iron (7.8 mg m(-3) for bare beam; 15.8 mg m(-3) for through deck), zinc (0.2 mg m(-3) for bare beam; 15.8 mg m(-3) for through deck), and manganese (0.9 mg m(-3) for bare beam; 1.5 mg m(-3) for through deck) often exceeding the American Conference of Governmental Industrial Hygienists Threshold Limit Values (TLVs). Number and mass concentrations were substantially reduced when using the upright system, although the total inhalable mass concentration remained above the TLV when welding through decking. The average diameters of the welding fume particles for both bare beam (31±17 nm) through deck conditions (34±34 nm) and the chemical composition of the particles indicated the presence of metallic nanoparticles. Stud welding exposes ironworkers to potentially high levels of biomechanical loading (primarily to the low back) and welding fume. The upright system used in this study improved exposure

  2. Immunotoxicology of arc welding fume: Worker and experimental animal studies

    Zeidler-Erdely, Patti C; Erdely, Aaron; Antonini, James M.

    2012-01-01

    Arc welding processes generate complex aerosols composed of potentially hazardous metal fumes and gases. Millions of workers worldwide are exposed to welding aerosols daily. A health effect of welding that is of concern to the occupational health community is the development of immune system dysfunction. Increased severity, frequency, and duration of upper and lower respiratory tract infections have been reported among welders. Specifically, multiple studies have observed an excess mortality ...

  3. A study of the bio-accessibility of welding fumes.

    Berlinger, Balázs; Ellingsen, Dag G; Náray, Miklós; Záray, Gyula; Thomassen, Yngvar

    2008-12-01

    The respiratory bio-accessibility of a substance is the fraction that is soluble in the respiratory environment and is available for absorption. In the case of respiratory exposure the amount of absorbed substance plays a main role in the biological effects. Extensive bio-accessibility studies have always been an essential requirement for a better understanding of the biological effects of different workplace aerosols, such as welding fumes. Fumes generated using three different welding techniques, manual metal arc (MMA) welding, metal inert gas (MIG) welding, and tungsten inert gas (TIG) welding were investigated in the present study. Each technique was used for stainless steel welding. Welding fumes were collected on PVC membrane filters in batches of 114 using a multiport air sampler. Three different fluids were applied for the solubility study: deionised water and two kinds of lung fluid simulants: lung epithelial lining fluid simulant (Gamble's solution) and artificial lung lining fluid simulant (Hatch's solution). In order to obtain sufficient data to study the tendencies in solubility change with time, seven different leaching periods were used (0.5, 1, 2, 4, 8, 16, 24 h), each of them with three replicates. The effect of dissolution temperature was also studied. The total amounts of selected metals in the three different welding fumes were determined after microwave-assisted digestion with the mixture of aqua regia and hydrofluoric acid. The most obvious observation yielded by the results is that the solubility of individual metals varies greatly depending on the welding technique, the composition of the leaching fluid and leaching time. This study shows that the most reasonable choice as a media for the bio-assessment of solubility might be Hatch's solution by a dissolution time of 24 h. PMID:19037486

  4. Optimizing fume and dust removal from the casthouse

    Klepper, G.; Dumont, J.; Speaight, T. (Paul Wurth S.A., Luxembourg (Luxembourg))

    1993-07-01

    For people to work safely in a healthy environment, today's legislation requires that fume collection systems have to be considered in the blast furnace casthouse. Computer-aided design and optimization helps in understanding complex relationships like flow characteristics, pressure drops, heat transfers, etc. Based on measured results from a reduced scale model, Paul Wurth has developed a parameterized computational fluid dynamics model to design effective installations for specific applications.

  5. Manganese speciation of laboratory-generated welding fumes

    Andrews, Ronnee N.; Keane, Michael; Hanley, Kevin W.; Feng, H. Amy; Ashley, Kevin

    2015-01-01

    The objective of this laboratory study was to identify and measure manganese (Mn) fractions in chamber-generated welding fumes (WF) and to evaluate and compare the results from a sequential extraction procedure for Mn fractions with that of an acid digestion procedure for measurement of total, elemental Mn. To prepare Mn-containing particulate matter from representative welding processes, a welding system was operated in short circuit gas metal arc welding (GMAW) mode using both stainless ste...

  6. The effect of thermal loading on laboratory fume hood performance.

    Johnston, J D; Chessin, S J; Chesnovar, B W; Lillquist, D R

    2000-11-01

    A modified version of the ANSI/ASHRAE 110-1995 Method of Testing Performance of Laboratory Fume Hoods was used to evaluate the relationship between thermal loading in a laboratory fume hood and subsequent tracer gas leakage. Three types of laboratory burners were used, alone and in combination, to thermally challenge the hood. Heat output from burners was measured in BTU/hr, which was based on the fuel heat capacity and flow rate. Hood leakage was measured between 2824 and 69,342 BTU/hr. Sulfur hexafluoride (SF6) was released at 23.5 LPM for each level of thermal loading. Duct temperature was also measured during the heating process. Results indicate a linear relationship for both BTU/hr vs. hood leakage and duct temperature vs. hood leakage. Under these test conditions, each increase of 10,000 BTU/hr resulted in an additional 4 ppm SF6 in the manikin's breathing zone (r2 = 0.68). An additional 3.1 ppm SF6 was measured for every 25 degrees F increase in duct temperature (r2 = 0.60). Both BTU/hr and duct temperature models showed p < 0.001. For these tests, BTU/hr was a better predictor of hood leakage than duct temperature. The results of this study indicate that heat output may compromise fume hood performance. This finding is consistent with those of previous studies. PMID:11062932

  7. In vitro method for medical risk assessment of laser fumes

    Malkusch, W.; Rehn, B.; Bruch, J.

    1995-02-01

    Laser processing of different materials may produce toxic fumes. In preventive occupational medicine it is necessary to evaluate valid hygienic standards for work places. The basis for such hygienic standards is the classification of laser fumes by their fibrogenic, emphysematous, immunological or other harmful potencies in biological assay systems. This paper is part of a European project on laser safety. Our part in this project is the development of a method for the investigation of lung responses using in vitro cell assays. The appropriate laser fume samples will be supplied by other groups in this European project. In contrast to the cell assays usually used in risk assessment, our method is based on isolated target cells in the lung, such as alveolar macrophages. The test criteria are mediator release, surfactant reactions, release of reactive oxygen species and cell proliferation. As demonstrated in the lung response to other dusts (minerals, fibres etc) these parameters are medically relevant factors in the pathogenic alveolar dust response. The paper gives basic information about the method using lung cell assays and the results of known substances, in comparison with a dust generated by laser processing.

  8. Pulmonary function of rats exposed to ethanol and gasoline fumes

    Saldiva, P.H.; Massad, E.; Caldeira, M.P.; Calheiros, D.F.; Saldiva, C.D.; Nicolelis, M.A.; Boehm, G.M.

    1985-01-01

    This paper describes the effects of repeated exposure to gasoline and ethanol exhaust fumes on the pulmonary mechanics of rats assessed by whole-body plethysmography. Two groups of 12 male Wistar albino rats each were tested before and after exposure to diluted gasoline or ethanol exhaust gases for 5 weeks, 8 h per day and 5 days per week. An additional group of 12 rats were exposed to clean air under the same experimental conditions. The variations of the functional parameters observed in the three groups before and after exposure were compared. Peak Expiratory Flow and Forced Expiratory Mean Flows in the ranges 0-25%, 25-50% and 50-75% of Forced Vital Capacity were significantly reduced in animals exposed to gasoline exhaust fumes, whereas the group exposed to ethanol exhaust fumes did not differ from the control group. This respiratory impairment is probably due to the presence of SO/sub 2/ and the quality of the hydrocarbons in gasoline exhaust gases.

  9. Comparative Microscopic Study of Human and Rat Lungs After Overexposure to Welding Fume

    Antonini, James M.; Roberts, Jenny R.; Schwegler-Berry, Diane; Mercer, Robert R.

    2013-01-01

    Welding is a common industrial process used to join metals and generates complex aerosols of potentially hazardous metal fumes and gases. Most long-time welders experience some type of respiratory disorder during their time of employment. The use of animal models and the ability to control the welding fume exposure in toxicology studies have been helpful in developing a better understanding of how welding fumes affect health. There are no studies that have performed a side-by-side comparison ...

  10. Soluble transition metals cause the pro-inflammatory effects of welding fumes in vitro

    Epidemiological studies have consistently reported a higher incidence of respiratory illnesses such as bronchitis, metal fume fever (MFF), and chronic pneumonitis among welders exposed to high concentrations of metal-enriched welding fumes. Here, we studied the molecular toxicology of three different metal-rich welding fumes: NIMROD 182, NIMROD c276, and COBSTEL 6. Fume toxicity in vitro was determined by exposing human type II alveolar epithelial cell line (A549) to whole welding fume, a soluble extract of fume or the 'washed' particulate. All whole fumes were significantly toxic to A549 cells at doses >63 μg ml-1 (TD 50; 42, 25, and 12 μg ml-1, respectively). NIMROD c276 and COBSTEL 6 fumes increased levels of IL-8 mRNA and protein at 6 h and protein at 24 h, as did the soluble fraction alone, whereas metal chelation of the soluble fraction using chelex beads attenuated the effect. The soluble fraction of all three fumes caused a rapid depletion in intracellular glutathione following 2-h exposure with a rebound increase by 24 h. In addition, both nickel based fumes, NIMROD 182 and NIMROD c276, induced significant reactive oxygen species (ROS) production in A549 cells after 2 h as determined by DCFH fluorescence. ICP analysis confirmed that transition metal concentrations were similar in the whole and soluble fractions of each fume (dominated by Cr), but significantly less in both the washed particles and chelated fractions. These results support the hypothesis that the enhanced pro-inflammatory responses of welding fume particulates are mediated by soluble transition metal components via an oxidative stress mechanism

  11. Lung Function Status of Workers Exposed to Welding Fume: A Preliminary Study

    Mulyana Mulyana; Nuri Purwito Purwito Adi; Meily L Kurniawidjaja; Andi Wijaya; Irawan Yusuf

    2016-01-01

    BACKGROUND: Exposure to welding fume in the workplace was associated with lung function disorders and occupational asthma. In this study, we determined lung function parameters in men workers exposed to welding fumes from heavy equipment manufacturer. This study is a preliminary study of biomonitoring program in worker exposed to welding fume as our main study. METHODS: A study with case-control design, random study, was conducted among welder (59 subjects) and non-welder (34 subjects) wi...

  12. Full-scale experimental research on fire fume refluence of sloped long and large curved tunnel

    2011-01-01

    A full-scale experimental research is conducted on the fire fume refluence of a sloped long and large curved tunnel in the underground plant of a hydraulic and hydropower engineering project under three different fire powers.As a result,the eddy effect and pattern of the fire fume flow in the tunnel in case of fire is discovered and the refluence of the fume layers in case of fire is observed.Through analysis of the temperature measurement resulted in the course of the experiment,the main characteristics and performance of the fire fume refluence are discussed under the three different fire powers.

  13. Cadmium and hypertension in exposed workers: A meta-analysis

    Tiziana Caciari; Angela Sancini; Mario Fioravanti; Teodorico Casale; Lucio Montuori; Maria Fiaschetti; Maria Pia Schifano; Giorgia Andreozzi; Nadia Nardone; Gianfranco Tomei; Manuela Ciarrocca; Maria Valeria Rosati; Francesco Tomei

    2013-01-01

    Objectives: In the general population, cadmium seems to be responsible for hypertension, atherosclerosis and an increase in acute coronary events. Therefore, the purpose of this meta-analysis was to analyze controlled studies conducted on cadmium and arterial pressure in occupationally-exposed workers. Materials and Methods: After analyzing all the relevant articles found in the literature, 6 publications were selected. Results: A higher prevalence of hypertension and higher values of systoli...

  14. Cadmium and hypertension in exposed workers: A meta-analysis

    Tiziana Caciari

    2013-06-01

    Full Text Available Objectives: In the general population, cadmium seems to be responsible for hypertension, atherosclerosis and an increase in acute coronary events. Therefore, the purpose of this meta-analysis was to analyze controlled studies conducted on cadmium and arterial pressure in occupationally-exposed workers. Materials and Methods: After analyzing all the relevant articles found in the literature, 6 publications were selected. Results: A higher prevalence of hypertension and higher values of systolic and diastolic blood pressure were recorded in the exposed subjects. Conclusions: Cadmium in occupationallyexposed individuals appears to induce an increase in systolic and diastolic blood pressure and an increase in the prevalence of hypertension.

  15. Irritative effects of fumes and aerosols of bitumen on the airways: results of a cross-shift study

    Raulf-Heimsoth, Monika; Pesch, Beate; Kappler, Martin; Marczynski, Boleslaw; Rihs, Hans Peter; Merget, Rolf; Bruening, Thomas [Institut der Ruhr-Universitaet Bochum, Berufsgenossenschaftliches Forschungsinstitut fuer Arbeitsmedizin (BGFA), Bochum (Germany); Schott, Klaus [Berufsgenossenschaft der Bauwirtschaft (BG BAU), Munich (Germany); Preuss, Ralf; Angerer, Juergen [Universitaet Erlangen, Institut und Poliklinik fuer Arbeits-, Sozial- und Umweltmedizin (IPASUM), Erlangen (Germany); Hahn, Jens Uwe [Berufsgenossenschaftliches Institut fuer Arbeitsschutz (BGIA), Sankt Augustin (Germany)

    2007-01-15

    Possible health hazards of fumes and aerosols of bitumen are in discussion, and data on their adverse effects on human airways under current exposure conditions are limited. To assess the irritative effects of exposure to fumes and aerosols of bitumen on the airways, a cross-sectional cross-shift study was conducted including external and internal exposure measurements, spirometry and especially non-invasive methods like nasal lavage collection and induction of sputum in order to identify and evaluate more precisely inflammatory process in the upper and lower airways. The cross-shift study comprised 74 mastic asphalt workers who were exposed to fumes and aerosols of bitumen and 49 construction workers without this exposure as reference group. Questionnaire, spirometry, ambient monitoring and urinary analysis were performed. Humoral and cellular parameters were measured in nasal lavage fluid (NALF) and induced sputum. For data analysis, a mixed linear model was performed on the different outcomes with exposure group, time of measurement (pre-, post-shift), current smoking, German nationality and age as fixed factors and subjects as random factor. Based on personal exposure measurements during shift, mastic asphalt workers were classified into a low ({<=}10 mg/m{sup 3}; n = 46) and a high (>10 mg/m{sup 3}; n = 28) exposure group. High exposure was accompanied by significant higher urinary post-shift concentrations of 1-hydroxypyrene and the sum of hydroxyphenanthrenes. Acute respiratory symptoms were reported more frequently in the high exposure group after shift. Significant cross-shift declines in lung function parameters (forced expiratory volume in 1 s [FEV{sub 1} (% predicted)] and forced vital capacity [FVC (% predicted)]) were measured in mastic asphalt workers. Pre-shift FEV{sub 1} (% predicted) and FVC (% predicted) were higher in the low exposure group. In pre- and post-shift NALF samples, interleukin (IL)-1{beta}-, IL-8- and total protein concentrations

  16. X-ray fluorescence analysis of welding fume particles

    A commercial standard filter set and two laboratory-made standard filter sets are compared via the analysis of generated welding fume samples by X-ray fluorescence. The latter standards are made by (1) hydrophobic-edge membrane filters spiked with prepared metal ion solutions, and (2) filters through which a dispersion of metal oxide powder in isopropanol has been drawn. The results are presented in table form. Precision (Pre) is the relative standard deviation of the six samples. Four main conclusions are enumerated

  17. Some engineering properties of heavy concrete added silica fume

    Akkaş, Ayşe [Suleyman Demirel University Teknoloji Fakültesi, Isparta (Turkey); Başyiğit, Celalettin; Esen, Serap [Suleyman Demirel University, Mühendislik Fakültesi, Isparta (Turkey)

    2013-12-16

    Many different types of building materials have been used in building construction for years. Heavy concretes can be used as a building material for critical building as it can contain a mixture of many heavy elements. The barite itself for radiation shielding can be used and also in concrete to produce the workable concrete with a maximum density and adequate structural strength. In this study, some engineering properties like compressive strength, elasticity modules and flexure strength of heavy concretes’ added Silica fume have been investigated.

  18. deFUME: Dynamic exploration of functional metagenomic sequencing data

    van der Helm, Eric; Geertz-Hansen, Henrik Marcus; Genee, Hans Jasper;

    2015-01-01

    Functional metagenomic selections represent a powerful technique that is widely applied for identification of novel genes from complex metagenomic sources. However, whereas hundreds to thousands of clones can be easily generated and sequenced over a few days of experiments, analyzing the data...... is time consuming and constitutes a major bottleneck for experimental researchers in the field. Here we present the deFUME web server, an easy-to-use web-based interface for processing, annotation and visualization of functional metagenomics sequencing data, tailored to meet the requirements of non...

  19. Cadmium and zinc reversibly arrest development of Artemia larvae

    Bagshaw, J.C.; Rafiee, P.; Matthews, C.O.; MacRae, T.H.

    1986-08-01

    Despite the widespread distribution of heavy metals such as cadmium and zinc in the environment and their well-known cytotoxicity and embryotoxicity in mammals, comparatively little is known about their effect on aquatic organisms, particularly invertebrates. Post-gastrula and early larval development of the brine shrimp, Artemia, present some useful advantages for studies of developmental aspects of environmental toxicology. Dormant encysted gastrulae, erroneously called brine shrimp eggs, can be obtained commercially and raised in the laboratory under completely defined conditions. Following a period of post-gastrula development within the cyst, pre-nauplius larvae emerge through a crack in the cyst shell. A few hours later, free-swimming nauplius larvae hatch. Cadmium is acutely toxic to both adults and nauplius larvae of Artemia, but the reported LC50s are as high as 10 mM, depending on larval age. In this paper the authors show that pre-nauplius larvae prior to hatching are much more sensitive to cadmium than are hatched nauplius larvae. At 0.1 ..mu..m, cadmium retards development and hatching of larvae; higher concentrations block hatching almost completely and thus are lethal. However, the larvae arrested at the emergence stage survive for 24 hours or more before succumbing to the effects of cadmium, and during this period the potentially lethal effect is reversible if the larvae are placed in cadmium-free medium. The effects of zinc parallel those of cadmium, although zinc is somewhat less toxic than cadmium at equal concentrations.

  20. OXIDATIVE STRESS IN SHEEP INDUCED BY CADMIUM CHLORIDE TOXICITY, WITH THERAPEUTIC EFFECTS OF ALPHA LIPOIC ACID

    Hussien Ali NAJI; Mohammad Mushgil ZENAD

    2015-01-01

    Cadmium (Cd) is a heavy toxic metal, with harmful effects on animals and public health. Recently the risk of cadmium toxicity is substantially regarded; the environmental pollution is increased due to multi- uses of this element in various industries. This study was performed to clarify the effects of acute cadmium toxicity in sheep with trail of using alpha lipoic acid as an antioxidant therapeutic substance. Fifteen male lambs aged from 5-to-7 months were divided equally in to three groups,...

  1. Effects of Cadmium on Phenolic Composition and Antioxidant Activities of Erica andevalensis

    Belén Márquez-García; M. Ángeles Fernández-Recamales; Francisco Córdoba

    2012-01-01

    We evaluated the effects of cadmium on phenolic composition of Erica andevalensis, an endemic protected heather that grows in mine affected soils. Plants cultivated under laboratory-controlled conditions were exposed to acute doses of cadmium to investigate the mechanisms this species possesses to survive in the presence of toxic metals in its natural habitat. Cadmium increased the total levels of phenolics and flavonoids compounds, and the total antioxidant capacity. Cinnamic acid derivative...

  2. The secretion, synthesis, and metabolism of cortisol and its downstream genes in the H-P-I axis of rare minnows (Gobiocypris rarus) are disrupted by acute waterborne cadmium exposure.

    Liu, Xiao-Hong; Xie, Bi-Wen; Wang, Zhi-Jian; Jin, Li; Zhang, Yao-Guang

    2016-01-01

    The H (hypothalamic)-P (pituitary)-I (interrenal) axis plays a critical role in the fish stress response and is regulated by several factors. Cadmium (Cd) is one of the most toxic heavy metals in the world, but its effects on the H-P-I axis of teleosts are largely unknown. Using rare minnow (Gobiocypris rarus) as an experimental animal, we found that Cd only disrupted the secretion and synthesis of cortisol. Neither hormones at the H or P level nor the expressions of their receptor genes (corticotropin-releasing hormone receptor (CRHR) and melanocortin receptor 2 (MC2R)) were affected. Steroidogenic acute regulator (StAR), CYP11A1 and CYP11B1, which encode the key enzymes in the cortisol synthesis pathway, were significantly up-regulated in the kidney (including the head kidney). The level of 11β-HSD2, which is required for the conversion of cortisol to cortisone, was increased in the kidney, intestine, brain, and hepatopancreas, whereas the expression of 11β-HSD1, which encodes the reverse conversion enzyme, was increased in the gill, kidney and almost unchanged in other tissues. The enzyme activity concentration of 11β-HSD2 was increased in the kidney as well. The level of glucocorticoid receptor (GR) decreased in the intestine, gill and muscle, and the key GR regulator FK506 binding protein5 (FKBP5) was up-regulated in the GR-decreased tissues, whereas the level of nuclear receptor co-repressor 1 (NCoR1), another GR regulator remained almost unchanged. Thus, GR, FKBP5 and 11β-HSD2 may be involved in Cd-induced cortisol disruption. PMID:27033032

  3. Micro Filler Effects of Silica-Fume on the Setting and Hardened Properties of Concrete

    V.M. Sounthararajan

    2013-08-01

    Full Text Available The use of supplementary cementitious material is gaining much attention owing to its high pozzolanic property and further improvement in strength properties. Silica-fume is one among the widely used pozzolanic material which exhibits high cementing efficiency due to high silica content. This study presents comprehends a detailed insight on the hydration properties of silica fume with cement. Silica fume consists of very fine particle size and contains silica content more than 90%. The cement hydration results in the formation of calcium hydroxide and this is consumed with the addition of silica fume and results in additional calcium silicate hydrate. This compound primarily envisages the strength and improved microstructure of concrete. Addition of silica-fume fills in the spaces between cement grains. The test results showed that higher compressive strength of concrete is obtained by using 8.0% of silica-fume at 7 and 28 days was 48.25 and 55.83 MPa, respectively. This phenomenon is frequently referred to as particle packing or micro-filling. Even if silica fume did not react chemically, the micro-filler effect would lead to significant improvements in the microstructure of concrete. A comprehensive review has been carried out in this study to give a good understanding on the advantages of pozzolanic properties of silica fume in cement concrete.

  4. 42 CFR 84.1147 - Silica mist test for dust, fume, and mist respirators; minimum requirements.

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Silica mist test for dust, fume, and mist... Efficiency Respirators and Combination Gas Masks § 84.1147 Silica mist test for dust, fume, and mist... nor more than 25 milligrams of silica mist, weighed as silica dust, per cubic meter of air. (d)...

  5. Investigation of durability of silica fume concretes in coastal structures within tidal zone

    In recent decade use of silica fume has been become greater in coastal concrete structures in the persona gulf, to increase durability of those establishments. In this research the durability of cement passers and concrete cubes with use of 7 and 10 percent of silica fume as a cement replacement have been investigated in three curing conditions (fresh water, coast of sea and simulation bonds) by measuring compressive strengths and capillary absorption. Silica fume specimens under wetting and drying condition showed more strength loss after 180 days compare to samples without silica fume or cured in the fresh water. In addition the greater silica fume amount in specimens cured within tidal zone and under wetting and drying simulation, the more water absorption by capillary. According to the results, good correspondence between simulated condition and real site exposure was obtained

  6. Influence of Silica Fume on Corrosion Behaviour of Reinforced Steel in Different Media

    2002-01-01

    Electrochemical and corrosion behaviour of reinforced steel embedded in cement pastes incorporating differentamounts of silica fume as a partial replacement of cement has been studied in chloride and sulphate solutionsby using different electrochemical techniques. The results indicate that, while steel passivity degree is Iow in thecontrol samples upon soaking in the corrosive media, it has been high in samples incorporating silica fume andincreased with increasing silica fume content. The improvement effect of silica fume may be attributed to the poresolution structure of the cement paste, which limits the mobility of aggressive ions near the surface of the steel. Themechanism of steel corrosion due to chloride and sulphate attack and passivation effect of silica fume are discussed.

  7. Acute respiratory distress in a silversmith

    Jignesh Mukeshkumar Parikh

    2014-01-01

    Full Text Available A 25-year-old young male patient presented in casualty department with severe respiratory distress on the fourth day from onset of symptoms. The patient was nonsmoker and had no antecedent medical or drug history. Prior to admission, patient had dry cough and bilateral pleuritic chest pain for the last three days. He was in severe respiratory distress with use of accessory muscles of respiration. On examination, he had heart rate of 120 beats/min, blood pressure (BP of 150/80, respiratory rate of 48-52/min and central cyanosis present. On systemic examination, reduced intensity of breath sounds with extensive rhonchi and crepitation was found in both lung fields, with other examination being within normal limits. On pulse oximetry, oxygen saturation was 28% on room air, which increased up to 36% with the help of 4 L oxygen via nasal prongs. PaO 2 /FiO 2 ratio was 100. Chest X-ray analysis was suggestive of non-cardiac pulmonary edema in view of bilateral fluffy opacity without cardiomegaly. In view of 2/3 positive criteria, his provisional diagnosis was Acute Respiratory Distress Syndrome (ARDS. He required mechanical ventilatory support and was gradually weaned over a period of 10 days. The patient was treated with broad spectrum antibiotics and other supportive measures. On re-evaluation of history, we found that he was a goldsmith by occupation, smelting silver and gold for the past 8-10 years. On the day of onset of symptoms, while smelting silver he was exposed to golden yellow fumes for around 15 minutes, with the quantum of exposure more than any other day earlier. From previous experience and analysis of similar silver metals, he was able to tell us that the silver was adulterated with large amount of cadmium on that day than before. Serum level of cadmium was 2.9 μg/L 6 days after initial exposure. At the time of discharge, he had residual opacities in the chest radiograph and resting oxygen saturation was 94% on room air.

  8. Evaluation of one-step luminescent cyanoacrylate fuming.

    Khuu, Alicia; Chadwick, Scott; Spindler, Xanthe; Lam, Rolanda; Moret, Sébastien; Roux, Claude

    2016-06-01

    One-step luminescent cyanoacrylates have recently been introduced as an alternative to the conventional cyanoacrylate fuming methods. These new techniques do not require the application of a luminescent post-treatment in order to enhance cyanoacrylate-developed fingermarks. In this study, three one-step polymer cyanoacrylates: CN Yellow Crystals (Aneval Inc.), PolyCyano UV (Foster+Freeman Ltd.) and PECA Multiband (BVDA), and one monomer cyanoacrylate: Lumikit™ (Crime Scene Technology), were evaluated against a conventional two-step cyanoacrylate fuming method (Cyanobloom (Foster+Freeman Ltd.) with rhodamine 6G stain). The manufacturers' recommended conditions or conditions compatible with the MVC™ 1000/D (Foster+Freeman Ltd.) were assessed with fingermarks aged for up to 8 weeks on non-porous and semi-porous substrates. Under white light, Cyanobloom generally gave better development than the one-step treatments across the substrates. Similarly when viewed under the respective luminescent conditions, Cyanobloom with rhodamine 6G stain resulted in improved contrast against the one-step treatments except on polystyrene, where PolyCyano UV and PECA Multiband gave better visualisation. Rhodamine 6G post-treatment of one-step samples did not significantly enhance the contrast of any of the one-step treatments against Cyanobloom/rhodamine 6G-treated samples. PMID:27105155

  9. High performance superplasticized silica fume mortars for ferrocement works

    Rathish Kumar P.

    2010-01-01

    Full Text Available Ferrocement works demand cement mortars of good workability and high strength. Reduction in water-cement ratio combined with a refined pore structure increases the compressive strength in addition to the enhancement of durability characteristics, but the workability decreases. Workability becomes important, as the mortar has to easily penetrate between the layers of the mesh wires. A reasonably workable high strength cement mortar can be obtained by using a high cement content coupled with the use of superplasticizers. These were also found to retain the cohesiveness and check undesirable bleeding and segregation. An experimental program was conducted to study the functional efficacy of an SNF condensate used as a water reducing superplasticizer. The compressive strength and flow characteristics of the mortars were determined to decide their suitability for ferrocement works. The parameters included the mix proportions, the grade of cement, age of curing and the dosage of superplasticizer. It was concluded from the study that the addition of an optimum dosage of superplasticizer improved the workability and strength characteristics of silica fume mortars. There was a late gain in the compressive strength of silica fume mortars.

  10. Effect of Silica Fume on two-stage Concrete Strength

    Abdelgader, H. S.; El-Baden, A. S.

    2015-11-01

    Two-stage concrete (TSC) is an innovative concrete that does not require vibration for placing and compaction. TSC is a simple concept; it is made using the same basic constituents as traditional concrete: cement, coarse aggregate, sand and water as well as mineral and chemical admixtures. As its name suggests, it is produced through a two-stage process. Firstly washed coarse aggregate is placed into the formwork in-situ. Later a specifically designed self compacting grout is introduced into the form from the lowest point under gravity pressure to fill the voids, cementing the aggregate into a monolith. The hardened concrete is dense, homogeneous and has in general improved engineering properties and durability. This paper presents the results from a research work attempt to study the effect of silica fume (SF) and superplasticizers admixtures (SP) on compressive and tensile strength of TSC using various combinations of water to cement ratio (w/c) and cement to sand ratio (c/s). Thirty six concrete mixes with different grout constituents were tested. From each mix twenty four standard cylinder samples of size (150mm×300mm) of concrete containing crushed aggregate were produced. The tested samples were made from combinations of w/c equal to: 0.45, 0.55 and 0.85, and three c/s of values: 0.5, 1 and 1.5. Silica fume was added at a dosage of 6% of weight of cement, while superplasticizer was added at a dosage of 2% of cement weight. Results indicated that both tensile and compressive strength of TSC can be statistically derived as a function of w/c and c/s with good correlation coefficients. The basic principle of traditional concrete, which says that an increase in water/cement ratio will lead to a reduction in compressive strength, was shown to hold true for TSC specimens tested. Using a combination of both silica fume and superplasticisers caused a significant increase in strength relative to control mixes.

  11. The effects of utilizing silica fume in Portland Cement Pervious Concrete

    Mann, Daniel Allen

    Silica fume has long been used as a supplementary cementing material to provide a high density, high strength, and durable building material. Silica fume has a particle size a fraction of any conventional cement, which allows it to increase concrete strength by decreasing the porosity especially near the aggregates surface. Because Portland Cement Pervious Concrete (PCPC) has a smaller bond area between aggregate and paste, silica fume has significant impacts on the properties of the PCPC. The research in this paper studies the workability of a cement paste containing silica fume in addition to analyzing the results of testing on Portland Cement Pervious Concrete mixtures that also contained silica fume. Testing conducted included a study of the effects of silica fume on cement's rheological properties at various dosage rates ranging from zero to ten percent by mass. It was determined that silica fume has negligible effects on the viscosity of cement paste until a dosage rate of five percent, at which point the viscosity increases rapidly. In addition to the rheological testing of the cement paste, trials were also conducted on the pervious concrete samples. Sample groups included mixes with river gravel and chipped limestone as aggregate, washed and unwashed, and two different void contents. Workability tests showed that mixtures containing a silica fume dosage rate of 5 percent or less had comparable or slightly improved workability when compared to control groups. Workability was found to decrease at a 7 percent dosage rate. Samples were tested for compressive strength at 7 and 28 days and splitting tensile strength at 28 days. It was found in most sample groups, strength increased with dosage rates of 3 to 5 percent but often decreased when the dosage reached 7 percent. Abrasion testing showed that both samples containing washed aggregate and samples containing silica fume exhibited a reduced mass loss.

  12. Modifying welding process parameters can reduce the neurotoxic potential of manganese-containing welding fumes

    Welding fumes (WF) are a complex mixture of toxic metals and gases, inhalation of which can lead to adverse health effects among welders. The presence of manganese (Mn) in welding electrodes is cause for concern about the potential development of Parkinson’s disease (PD)-like neurological disorder. Consequently, from an occupational safety perspective, there is a critical need to prevent adverse exposures to WF. As the fume generation rate and physicochemical characteristics of welding aerosols are influenced by welding process parameters like voltage, current or shielding gas, we sought to determine if changing such parameters can alter the fume profile and consequently its neurotoxic potential. Specifically, we evaluated the influence of voltage on fume composition and neurotoxic outcome. Rats were exposed by whole-body inhalation (40 mg/m3; 3 h/day × 5 d/week × 2 weeks) to fumes generated by gas–metal arc welding using stainless steel electrodes (GMA-SS) at standard/regular voltage (25 V; RVSS) or high voltage (30 V; HVSS). Fumes generated under these conditions exhibited similar particulate morphology, appearing as chain-like aggregates; however, HVSS fumes comprised of a larger fraction of ultrafine particulates that are generally considered to be more toxic than their fine counterparts. Paradoxically, exposure to HVSS fumes did not elicit dopaminergic neurotoxicity, as monitored by the expression of dopaminergic and PD-related markers. We show that the lack of neurotoxicity is due to reduced solubility of Mn in HVSS fumes. Our findings show promise for process control procedures in developing prevention strategies for Mn-related neurotoxicity during welding; however, it warrants additional investigations to determine if such modifications can be suitably adapted at the workplace to avert or reduce adverse neurological risks

  13. The vapour pressures over saturated aqueous solutions of cadmium chloride, cadmium bromide, cadmium iodide, cadmium nitrate, and cadmium sulphate

    Apelblat, Alexander [Department of Chemical Engineering, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel)]. E-mail: apelblat@bgu.ac.il; Korin, Eli [Department of Chemical Engineering, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel)

    2007-07-15

    Vapour pressures of water over saturated solutions of cadmium salts (chloride, bromide, iodide, nitrate, and sulphate) were determined over the temperature range 280 K to 322 K and compared with the literature data. The vapour pressures determined were used to obtain the water activities, osmotic coefficients and the molar enthalpies of vaporization in the (cadmium salt + water) systems.

  14. The vapour pressures over saturated aqueous solutions of cadmium chloride, cadmium bromide, cadmium iodide, cadmium nitrate, and cadmium sulphate

    Vapour pressures of water over saturated solutions of cadmium salts (chloride, bromide, iodide, nitrate, and sulphate) were determined over the temperature range 280 K to 322 K and compared with the literature data. The vapour pressures determined were used to obtain the water activities, osmotic coefficients and the molar enthalpies of vaporization in the (cadmium salt + water) systems

  15. Radon exhalation rates of concrete modified with fly ash and silica fumes

    The radiological impact of the environmental gas radon to the health of general public is of concern since many decades. Cement used for the construction blended with fly ash and silica fumes is recommended by Government in order to avoid the soil and environmental pollution. But these addition step-up the Indoor radon level in the dwelling due to radioactivity contents. The exhalation of radon from concrete blended with silica fumes and fly ash depends upon addition level, porosity, moisture and radioactivity content. In order to optimize the level of substitution of silica fumes and fly ash, measurements of radon exhalation rates from the concrete blended with different proportions of fly ash and silica fumes was carried out using active scintillation radon monitor. The effect of porosity, moisture, back diffusion and radioactivity content of the concrete on exhalation rates is studied. The measured exhalation rates were extrapolated for indoor radon concentration and effective dose equivalent using ICRP, 1987 recommendations. (author)

  16. Analysis of the Damping Behavior and Microstructure of Cement Matrix with Silane-treated Silica Fume

    OU Jinping; LIU Tiejun; LI Jiahe

    2006-01-01

    The surface treatment of silica fume with silane coupling agent prior to incorporation in a cement mortar resulted in composites exhibiting increases in loss tangent by 5%-200% and storage modulus by 10%-20%, relative to the value obtained by using as-received silica fume. The scanning electron microscopy (SEM) images indicate that there is a morphological difference in the cement paste with treated and as-received silica fume. The X-ray diffraction (XRD), infrared (IR) spectrum analyses and mercury intrusion porosimetry (MIP) have provided evidence to understand the reaction mechanism between treated silica fume and the hydrate product of cement. This has led to the establishment of an initial microscopic model describing the damping behavior of cement matrix.

  17. Cadmium inhibits acid secretion in stimulated frog gastric mucosa

    Cadmium, a toxic environmental pollutant, affects the function of different organs such as lungs, liver and kidney. Less is known about its toxic effects on the gastric mucosa. The aim of this study was to investigate the mechanisms by which cadmium impacts on the physiology of gastric mucosa. To this end, intact amphibian mucosae were mounted in Ussing chambers and the rate of acid secretion, short circuit current (Isc), transepithelial potential (Vt) and resistance (Rt) were recorded in the continuous presence of cadmium. Addition of cadmium (20 μM to 1 mM) on the serosal but not luminal side of the mucosae resulted in inhibition of acid secretion and increase in NPPB-sensitive, chloride-dependent short circuit current. Remarkably, cadmium exerted its effects only on histamine-stimulated tissues. Experiments with TPEN, a cell-permeant chelator for heavy metals, showed that cadmium acts from the intracellular side of the acid secreting cells. Furthermore, cadmium-induced inhibition of acid secretion and increase in Isc cannot be explained by an action on: 1) H2 histamine receptor, 2) Ca2+ signalling 3) adenylyl cyclase or 4) carbonic anhydrase. Conversely, cadmium was ineffective in the presence of the H+/K+-ATPase blocker omeprazole suggesting that the two compounds likely act on the same target. Our findings suggest that cadmium affects the functionality of histamine-stimulated gastric mucosa by inhibiting the H+/K+-ATPase from the intracellular side. These data shed new light on the toxic effect of this dangerous environmental pollutant and may result in new avenues for therapeutic intervention in acute and chronic intoxication.

  18. Comparative microscopic study of human and rat lungs after overexposure to welding fume.

    Antonini, James M; Roberts, Jenny R; Schwegler-Berry, Diane; Mercer, Robert R

    2013-11-01

    Welding is a common industrial process used to join metals and generates complex aerosols of potentially hazardous metal fumes and gases. Most long-time welders experience some type of respiratory disorder during their time of employment. The use of animal models and the ability to control the welding fume exposure in toxicology studies have been helpful in developing a better understanding of how welding fumes affect health. There are no studies that have performed a side-by-side comparison of the pulmonary responses from an animal toxicology welding fume study with the lung responses associated with chronic exposure to welding fume by a career welder. In this study, post-mortem lung tissue was donated from a long-time welder with a well-characterized work background and a history of extensive welding fume exposure. To simulate a long-term welding exposure in an animal model, Sprague-Dawley rats were treated once a week for 28 weeks by intratracheal instillation with 2mg of a stainless steel, hard-surfacing welding fume. Lung tissues from the welder and the welding fume-treated rats were examined by light and electron microscopy. Pathological analysis of lung tissue collected from the welder demonstrated inflammatory cell influx and significant pulmonary injury. The poor and deteriorating lung condition observed in the welder examined in this study was likely due to exposure to very high levels of potentially toxic metal fumes and gases for a significant number of years due to work in confined spaces. The lung toxicity profile for the rats treated with welding fume was similar. For tissue samples from both the welder and treated rats, welding particle accumulations deposited and persisted in lung structures and were easily visualized using light microscopic techniques. Agglomerates of deposited welding particles mostly were observed within lung cells, particularly alveolar macrophages. Analysis of individual particles within the agglomerates showed that these

  19. Cadmium status in Egypt

    2001-01-01

    It is inferred from these studies that releases of Cd are still increasing and it is recommended that measures must be taken to reduce emissions of cadmium. Any cadmium discharged into the Egyptian environment may move from one compartment to another at varying rates,resulting in an accumulation in compartments such as soils and biota. Such accumulation can be expected to increase with continued emissions,and attention should be given to all sources of cadmium, natural as well as anthropogenic especially in the industrial cities in Egypt. Cadmium present in sewage, as well as industrial effluent (also, other liquid and solid wastes) and sewage sludge will increase levels in soils and is xpected to contribute to dietary levels and body burdens. The current information indicates that such effects may have to be evaluated over long periods of time, possibly as long as 50 - 100 years.

  20. Cement with silica fume and granulated blast-furnace slag: strength behavior and hydration

    Bonavetti, V. L.; Castellano, C.; Donza, H.; Rahhal, V.F.; Irassar, E. F.

    2014-01-01

    This paper analyses the influence of portland cement replacement by silica fume (up to 10%) and/or granulated blast furnace slag (up to 70%) on the hydration cement (XRD, heat of hydration, non evaporable water content and calcium hydroxide content) curing under sealed conditions and their effect on the mechanical strength. The obtained results indicate that binary cements containing silica fume and ternary cements there was a significant increase of hydration rate at early age. At later a...

  1. Cytotoxic effects of four types of welding fumes on macrophages in vitro: a comparative study.

    Pasanen, J T; Gustafsson, T E; Kalliomäki, P L; Tossavainen, A; Järvisalo, J O

    1986-01-01

    The effects of fume particles given off by the manual metal arc (MMA) and metal inert gas (MIG) welding of stainless steel (SS) and mild steel (MS) were studied on rat alveolar macrophage cultures in vitro. The fumes were generated by welding, and particulate material obtained was collected on membrane filters. The macrophage cultures were exposed to the total dust and to its water-insoluble fractions. Cell variability and the release of both lactate dehydrogenase and one lysosomal enzyme from the cells to the medium were measured after an exposure period of 24 h. The cytotoxic control dust was DQ 12 quartz, and the inert control dust was pure titanium dioxide. According to the parameters studied, SS/MMA and MS/MMA welding fumes were cytotoxic to rat alveolar macrophages. The cytotoxic effect of SS/MMA welding fumes decreased after the samples had been washed with phosphate-buffered salt solution. The MIG welding fumes of SS and MS had markedly smaller effects on the cells. Diluted solutions of potassium chromate were also tested in order to investigate its role in the cytotoxicity of SS/MMA welding fumes. The results suggest that hexavalent chromium may be responsible for the cytotoxicity of SS/MMA. PMID:3701879

  2. Mutagenicity and polycyclic aromatic hydrocarbon content of fumes from heated cooking oils produced in Taiwan

    Chiang, Tai-An; Ko, Ying-Chin [Graduate Institute of Medicine, Kaohsiung Medical College, Kaohsiung (Taiwan, Province of China); Wu, Pei-Fen [Department of Industrial Safety and Hygiene, Tajen Junior College of Pharmacy, Ping-Tung (Taiwan, Province of China); Wang, Li-Fang [School of Chemistry, Kaohsiung Medical College, Kaohsiung (Taiwan, Province of China); Lee, Huei [Department of Biochemistry, Chung San Medical and Dental College, Taichung (Taiwan, Province of China); Lee, Chien-Hung [School of Public Health, Kaohsiung Medical College, Kaohsiung (Taiwan, Province of China)

    1997-11-28

    According to epidemiologic studies, exposure of women to fumes from cooking oils appears to be an important risk factor for lung cancer. Fume samples from three different commercial cooking oils frequently used in Taiwan were collected and analyzed for mutagenicity in the Salmonella/microsome assay. Polycyclic aromatic hydrocarbons were extracted from the samples and identified by HPLC chromatography. Extracts from three cooking oil fumes were found to be mutagenic in the presence of S9 mix. All samples contained dibenz(a,h)anthracene (DB(a,h)A) and benz(a)anthracene (B(a)A). Concentration of DB(a,h)A and B(a)A were 1.9 and 2.2 {mu}g/m{sup 3} in fumes from lard oil, 2.1 and 2.3 {mu}g/m{sup 3} in soybean oil, 1.8 and 1.3 {mu}g/m{sup 3} in peanut oil, respectively. Benzo(a)pyrene (B(a)P) was identified in fume samples of soybean and peanut oil, in concentrations of 19.6 and 18.3 {mu}g/m{sup 3}, in this order. These results provide experimental evidence and support the findings of epidemiologic observations, in which women exposed to the emitted fumes of cooking oils are at increased risk of contracting lung cancer

  3. Acute toxicity of copper and cadmium for piauçu, Leporinus macrocephalus, and curimatã, Prochilodus vimboides - DOI: 10.4025/actascibiolsci.v31i3.5069 Acute toxicity of copper and cadmium for piauçu, Leporinus macrocephalus, and curimatã, Prochilodus vimboides - DOI: 10.4025/actascibiolsci.v31i3.5069

    Luis Fernando Loureiro Fernandes; Rodrigo Nunes Oss; Adriana Regina Chippari-Gomes; Rafael de Almeida Magris; Levy Carvalho Gomes

    2009-01-01

    Ninety-six-hour static bioassays were conducted in the laboratory to determine lethal concentrations (96-h LC50) of copper and cadmium for curimatã (Prochilodus vimboides) and piauçu (Leporinus macrocephalus). The 96-h LC50 of copper were 0.047 and 0.090 mg L-1, and of cadmium 3.16 and 7.42 mg L-1 for curimatã and piauçu, respectively. Curimatã is a preferred indigenous species for toxicological studies in the Doce River basin due to its availability in the hatcheries of the region and high s...

  4. High-resolution NMR spectroscopy under the fume hood.

    Küster, Simon K; Danieli, Ernesto; Blümich, Bernhard; Casanova, Federico

    2011-08-01

    This work reports the possibility to acquire high-resolution (1)H NMR spectra with a fist-sized NMR magnet directly installed under the fume hood. The small NMR sensor based on permanent magnets was used to monitor the trimerization of propionaldehyde catalyzed by indium trichloride in real time by continuously circulating the reaction mixture through the magnet bore in a closed loop with the help of a peristaltic pump. Thanks to the chemical selectivity of NMR spectroscopy the progress of the reaction can be monitored on-line by determining the concentrations of both reactant and product from the area under their respective lines in the NMR spectra as a function of time. This in situ measurement demonstrates that NMR probes can be used in chemistry laboratories, e.g. for reaction optimization, or installed at specific points of interest along industrial process lines. Therefore, it will open the door for the implementation of feedback control based on spectroscopic NMR data. PMID:21698335

  5. Analysis of heat transfer and contaminant transport in fume hoods

    The paper presents the analysis of three-dimensional flow patterns and the associated heat and mass transfer mechanisms in a fume hood enclosure. The flow enters the hood through the front window opening (positive x-direction) and leaves the cupboard through an opening on the top of the hood (positive z-direction). The flow was assumed to be fully turbulent. The flow pattern for different sash openings were studied. The flow pattern around an object located at the bottom of the hood was studied for different locations of the object. It was found that air entering the hood proceeds directly to the back wall, impinges it and turns upward toward the top wall and exits through the outlet. The flow finds its way around any object forming a recirculating region at its training surface. With an increase in the sash opening, the velocity becomes higher and the fluid traces the path to the outlet more quickly. The volume occupied by recirculating flow decreases with increase in sash opening. Both temperature and concentration were found to be maximum near the source and gradually decreased as the heated air or gaseous contaminant entrained with incoming air. The local concentration decreased with increase in sash opening area. The results will be very useful to design experiments with optimum sash opening providing adequate disposal of contaminants with minimum use of conditioned air inside the room

  6. The detection of drugs of abuse in fingerprints using Raman spectroscopy II: cyanoacrylate-fumed fingerprints

    Day, Joanna S.; Edwards, Howell G. M.; Dobrowski, Steven A.; Voice, Alison M.

    2004-07-01

    This paper describes the application of Raman spectroscopy to the detection of exogenous substances in cyanoacrylate-fumed fingerprints. The scenario considered was that of an individual handling a substance and subsequently depositing a contaminated fingerprint. These fingerprints were enhanced by cyanoacrylate fuming, a process in which a layer of white cyanoacrylate polymer is deposited on the fingerprint material, enabling visual detection. Five drugs of abuse (codeine phosphate, cocaine hydrochloride, amphetamine sulphate, barbital and nitrazepam) and five non-controlled substances of similar appearance, which may be used in the adulteration of drugs of abuse (caffeine, aspirin, paracetamol, starch and talc), were used. The substances studied could be clearly distinguished using their Raman spectra and were all successfully detected in cyanoacrylate-fumed fingerprints. Photobleaching was necessary to reduce the fluorescence background in the spectra of some substances. Raman spectra obtained from the substances in cyanoacrylate-fumed fingerprints were of a similar quality to spectra obtained from the substances under normal sampling conditions, however, interfering Raman bands arising from the cyanoacrylate polymer were present in the spectra. In most cases the only interfering band was the CN stretching mode of the polymer, and there were no cases where the interfering bands prevented identification of the substances. If necessary, the interfering bands could be successfully removed by spectral subtraction. The most difficult aspect of the detection of these substances in cyanoacrylate-fumed fingerprints was visually locating the substance in the fingerprint beneath the polymer layer in order to obtain a Raman spectrum.

  7. A Review for Characterization of Silica Fume and Its Effects on Concrete Properties

    Mohammad Panjehpour

    2011-12-01

    Full Text Available Mineral additions which are also known as mineral admixtures have been used in Portland cement for many years. There are two types of additions which are commonly mixed into the Portland clinker or blended directly with cement these days. They are crystalline, also known as hydraulically inactive additions and pozzolanic, which are hydraulically active additions. Silica fume is very reactive pozzolan, while it is used in concrete because of its fine particles, large surface area and high SiO2 content. Silica fume is much fined separated silica obtained as a by-product in industry. It is used as an admixture in the concrete mix and it has significant effects on the properties of the resulting material. Simultaneously, silica fume can be also utilized in production of refectory and porcelain, to increase intensity and durability. In addition, it can improve the overall performance of the material as filler used in coating resin, paint, rubber and other high molecular materials. This review paper discusses the effects of silica fume on the concrete properties such as strength, modulus, ductility, permeability, chemical attack resistance, corrosion, freeze-thaw durability, creep rate. Characterisation of silica fume as well as its physical and chemical properties will also be reviewed in this paper.

  8. Sulfate Attack Resistance of Air-entrained Silica Fume Concrete under Dry-Wet Cycle Condition

    YANG Jiansen; WANG Peiming; LI Haoxin; YANG Xu

    2016-01-01

    Based on the erosion resistant coefficient, the effects of water-cement ratio, air-entrained, silica fume content and sand ratio on the sulfate attack resistance of air-entrained silica fume concrete were studied by orthogonal experiments in order to explore its sulfate attack resistance under dry-wet condition. A more signiifcant model of concrete resistance to sulfate attack was also established, thus this work provided a strategy reference for quantitative design of sulfate attack resistant concrete. The experimental results show that dry-wet cycle deteriorates the concrete resistance to the sulfate attack, and leads to the remarkable declines of concrete strength and sulfate resistance. Air bubbles in the air-entrained silica fume concrete lower and delay the damage resulted from the crystallization sulfate salt. However this delay gradually disappears when most of the close bubbles are breached by the alternative running of the sulfate salt crystallization and the permeating pressure, and then the air bubbles are iflled with sulfate salt crystallization. The concrete is provided with the strongest sulfate resistance when it is prepared with the 0.47 water-binder ratio, 6.0% air-entrained, 5% silica fume and 30% sand ratio. The erosion resistant coefifcientsK80 andK150 of this concrete are increased by 9%, 7%, 9%, and 5% respectively as compared with those of concretes without silica fume and air entraining.

  9. Influence of cadmium exposure on selected hematological parameters in freshwater teleost, Notemigonus crysoleucas

    Benson, W.H.; Baer, K.N.; Stackhouse, R.A.; Watson, C.F.

    1987-02-01

    The use of hematological parameters for assessing the acute toxicity of heavy metals to mammals has shown considerable promise. These parameters include the measurement of blood glucose, hematocrit, and a variety of enzymes. The present investigation was undertaken to evaluate the use of selected hematological parameters in aquatic organisms. Exposure of Notemigonus crysoleucas to cadmium resulted in a 96-hr /sup LC/50 value of 3.15 mg Cd/liter. The influence of cadmium on selected hematological parameters was examined following 96 hr of exposure to 0, 1.35, and 2.40 mg Cd/liter. Cadmium exposure produced significant alterations in the levels of glucose, aspartate aminotransaminase, and alanine aminotransaminase. Hematocrit was not altered by exposure to cadmium. These results indicate that glucose and transaminases may be useful as diagnostic tests for cadmium exposure in aquatic organisms.

  10. Testing Silica Fume-Based Concrete Composites under Chemical and Microbiological Sulfate Attacks

    Adriana Estokova

    2016-04-01

    Full Text Available Current design practices based on descriptive approaches to concrete specification may not be appropriate for the management of aggressive environments. In this study, the durability of cement-based materials with and without the addition of silica fume, subjected to conditions that leach calcium and silicon, were investigated. Chemical corrosion was simulated by employing various H2SO4 and MgSO4 solutions, and biological corrosion was simulated using Acidithiobacillus sp. bacterial inoculation, leading to disrupted and damaged surfaces; the samples’ mass changes were studied following both chemical and biological attacks. Different leaching trends were observed via X-ray fluorescence when comparing chemical with biological leaching. Lower leaching rates were found for concrete samples fortified with silica fume than those without silica fume. X-ray diffraction and scanning electron microscopy confirmed a massive sulfate precipitate formation on the concrete surface due to bacterial exposure.

  11. Nanocomposite electrolytes with fumed silica in poly(methyl methacrylate): thermal, rheological and conductivity studies

    Ahmad, Shahzada; Agnihotry, S.A. [Electronic Materials Division, National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012 (India); Ahmad, Sharif [Materials Research Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110025 (India)

    2005-01-10

    Composite polymer electrolytes (CPEs), were prepared by adding hydrophilic fumed silica in different proportions upto 5wt.% to gel polymeric electrolyte (GPE) comprising liquid electrolyte (1M LiClO{sub 4} in propylene carbonate) immobilized with 15wt.% poly(methyl methacrylate) (PMMA). The effect of fumed silica content in the CPEs on the ionic conductivity and viscosity over a wide temperature range was investigated. The resultant CPEs showed room temperature conductivity ({sigma}{sub 25}) as high as 3.8mScm{sup -1} along with viscosity value of 3700P for 2wt.% SiO{sub 2} addition. Fumed silica addition both to the liquid electrolyte and to the GPE exhibits similar conductivity behaviour and this suggests a passive role of PMMA. The shear thinning behaviour, pointing towards easy processablity, high thermal stability and low volatility, makes these CPEs potential candidates as solid-like electrolytes for electrochemical devices. (author)

  12. Risk of ischemic heart disease following occupational exposure to welding fumes

    Mocevic, Emina; Kristiansen, Pernille; Bonde, Jens Peter

    2015-01-01

    PURPOSE: Air pollution has been linked to an increased risk of ischemic heart disease (IHD), but less is known about occupational exposure to welding fumes and the risk of IHD. The objective of this paper was to review the epidemiological evidence on causal links between welding fume exposure and...... risk of IHD and to investigate whether the risk of IHD depends on specific welding characteristics. METHODS: A systematic search in Medline 1979-2013 and EMBASE 1974-2013 identified 18 epidemiological studies with at least one risk estimate of IHD morbidity or mortality among workers exposed to welding...... fumes. Following an assessment of completeness of reporting, confounding, and bias, each risk estimate was characterized as more or less reliable. Pooled risk estimates were computed across studies by random effect meta-analyses. RESULTS: The weighted relative risk (RR) for IHD following exposure to...

  13. Non-occupational exposure to paint fumes during pregnancy and fetal growth in a general population

    Sørensen, Mette; Andersen, Anne-Marie N; Raaschou-Nielsen, Ole

    2010-01-01

    Occupational exposure to organic solvents during pregnancy has been associated with reduced fetal growth. Though organic solvents in the form of paint fumes are also found in the home environment, no studies have investigated the effect of such exposure in a general population. We studied...... associations between residential exposure to paint fumes during pregnancy and fetal growth within the Danish National Birth Cohort which consecutively recruited pregnant women from 1996 to 2002 from all over Denmark. Around the 30th pregnancy week, 19,000 mothers were interviewed about use of paint in their...... of preterm birth after adjustment for potential confounders. Our results suggest that there are no causal relationship between non-occupational exposure to paint fumes in the residence during pregnancy and fetal growth....

  14. Nephrotoxicity of cadmium & lead.

    Gonick, H C

    2008-10-01

    Cadmium and lead are divalent cations with a propensity to settle in the proximal tubule of the nephron, leading to nephrotoxicity. The pathophysiological results, however, tend to diverge. Cadmium in sufficient cumulative dosage leads to the production of the Fanconi syndrome, a generalized proximal tubular reabsorptive defect thought to be related to inhibition of both ATP production and Na-K-ATPase activity. On the other hand, lead accumulation in the proximal tubule leads to hyperuricaemia and gout, presumably by inhibiting uric acid secretion, and diminished glomerular filteration rate (GFR). Fanconi syndrome is seen unusually only in children and experimental animals. Cadmium nephrotoxicity is heralded by increased excretion of beta2-microglobulin, retinol binding protein and alpha1-microglobulin, indicative of decreased proximal tubule function. Beta2-microglobulinuria is not found in lead nephropathy. In lead nephropathy albuminuria is absent or minimal whereas in cadmium nephropathy albuminuria is variable. From the standpoint of pathology, both entities are characterized by tubulointerstitial disease and fibrosis, but only early lead nephropathy is characterized by the presence of proximal tubule nuclear inclusion bodies, due to the combination of lead with a lead binding-protein. PMID:19106433

  15. 42 CFR 84.1153 - Dust, fume, mist, and smoke tests; canister bench tests; gas masks canisters containing filters...

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Dust, fume, mist, and smoke tests; canister bench... RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators and Combination Gas Masks § 84.1153...

  16. 42 CFR 84.1152 - Silica dust loading test; respirators designed as protection against dusts, fumes, and mists...

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Silica dust loading test; respirators designed as protection against dusts, fumes, and mists having an air contamination level less than 0.05 milligram per... Silica dust loading test; respirators designed as protection against dusts, fumes, and mists having...

  17. Exposure to environmental levels of waterborne cadmium impacts corticosteroidogenic and metabolic capacities, and compromises secondary stressor performance in rainbow trout

    Highlights: •Low level chronic waterborne cadmium exposure did not evoke a plasma cortisol response in rainbow trout. •Chronic cadmium exposure increases liver and gill metabolic capacities. •Chronic cadmium exposure disrupts head kidney steroidogenic capacity. •Chronic cadmium exposure disrupts glucocorticoid and mineralocorticoid receptor protein expressions in target tissues. •Chronic cadmium exposure compromises physiological performances to a secondary stressor in trout. -- Abstract: The physiological responses to waterborne cadmium exposure have been well documented; however, few studies have examined animal performances at low exposure concentrations of this metal. We tested the hypothesis that longer-term exposure to low levels of cadmium will compromise the steroidogenic and metabolic capacities, and reduce the cortisol response to a secondary stressor in fish. To test this, juvenile rainbow trout (Oncorhynchus mykiss) were exposed to 0 (control), 0.75 or 2.0 μg/L waterborne cadmium in a flow-through system and were sampled at 1, 7 and 28 d of exposure. There were only very slight disturbances in basal plasma cortisol, lactate or glucose levels in response to cadmium exposure over the 28 d period. Chronic cadmium exposure significantly affected key genes involved in corticosteroidogenesis, including melanocortin 2 receptor, steroidogenic acute regulatory protein and cytochrome P450 side chain cleavage enzyme. At 28 d, the high cadmium exposure group showed a significant drop in the glucocorticoid receptor and mineralocorticoid receptor protein expressions in the liver and brain, respectively. There were also perturbations in the metabolic capacities in the liver and gill of cadmium-exposed trout. Subjecting these fish to a secondary handling disturbance led to a significant attenuation of the stressor-induced plasma cortisol, glucose and lactate levels in the cadmium groups. Collectively, although trout appears to adjust to subchronic exposure

  18. Exposure to environmental levels of waterborne cadmium impacts corticosteroidogenic and metabolic capacities, and compromises secondary stressor performance in rainbow trout

    Sandhu, Navdeep [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); McGeer, James C. [Department of Biology, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5 (Canada); Vijayan, Mathilakath M., E-mail: matt.vijayan@ucalgary.ca [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2014-01-15

    Highlights: •Low level chronic waterborne cadmium exposure did not evoke a plasma cortisol response in rainbow trout. •Chronic cadmium exposure increases liver and gill metabolic capacities. •Chronic cadmium exposure disrupts head kidney steroidogenic capacity. •Chronic cadmium exposure disrupts glucocorticoid and mineralocorticoid receptor protein expressions in target tissues. •Chronic cadmium exposure compromises physiological performances to a secondary stressor in trout. -- Abstract: The physiological responses to waterborne cadmium exposure have been well documented; however, few studies have examined animal performances at low exposure concentrations of this metal. We tested the hypothesis that longer-term exposure to low levels of cadmium will compromise the steroidogenic and metabolic capacities, and reduce the cortisol response to a secondary stressor in fish. To test this, juvenile rainbow trout (Oncorhynchus mykiss) were exposed to 0 (control), 0.75 or 2.0 μg/L waterborne cadmium in a flow-through system and were sampled at 1, 7 and 28 d of exposure. There were only very slight disturbances in basal plasma cortisol, lactate or glucose levels in response to cadmium exposure over the 28 d period. Chronic cadmium exposure significantly affected key genes involved in corticosteroidogenesis, including melanocortin 2 receptor, steroidogenic acute regulatory protein and cytochrome P450 side chain cleavage enzyme. At 28 d, the high cadmium exposure group showed a significant drop in the glucocorticoid receptor and mineralocorticoid receptor protein expressions in the liver and brain, respectively. There were also perturbations in the metabolic capacities in the liver and gill of cadmium-exposed trout. Subjecting these fish to a secondary handling disturbance led to a significant attenuation of the stressor-induced plasma cortisol, glucose and lactate levels in the cadmium groups. Collectively, although trout appears to adjust to subchronic exposure

  19. Stabilization of heavy metals in MSWI fly ash using silica fume

    Li, Xinying; Chen, Quanyuan [School of Environment Science and Engineering, Donghua University, Shanghai 201620 (China); State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620 (China); Zhou, Yasu [School of Environment Science and Engineering, Donghua University, Shanghai 201620 (China); Tyrer, Mark [Mineral Industry Research Organisation, Solihull B37 7HB (United Kingdom); Yu, Yang [School of Environment Science and Engineering, Donghua University, Shanghai 201620 (China)

    2014-12-15

    Highlights: • The stabilization of heavy metals in MSWI fly ash was investigated. • The addition of silica fume effectively reduced the leaching of Pb and Cd. • The relation of solid phase transformation and leaching behavior of heavy metals was discussed. - Abstract: The objective of this work was to investigate the feasibility and effectiveness of silica fume on stabilizing heavy metals in municipal solid waste incineration (MSWI) fly ash. In addition to compressive strength measurements, hydrated pastes were characterized by X-ray diffraction (XRD), thermal-analyses (DTA/TG), and MAS NMR ({sup 27}Al and {sup 29}Si) techniques. It was found that silica fume additions could effectively reduce the leaching of toxic heavy metals. At the addition of 20% silica fume, leaching concentrations for Cu, Pb and Zn of the hydrated paste cured for 7 days decreased from 0.32 mg/L to 0.05 mg/L, 40.99 mg/L to 4.40 mg/L, and 6.96 mg/L to 0.21 mg/L compared with the MSWI fly ash. After curing for 135 days, Cd and Pb in the leachates were not detected, while Cu and Zn concentrations decreased to 0.02 mg/L and 0.03 mg/L. The speciation of Pb and Cd by the modified version of the European Community Bureau of Reference (BCR) extractions showed that these metals converted into more stable state in hydrated pastes of MSWI fly ash in the presence of silica fume. Although exchangeable and weak-acid soluble fractions of Cu and Zn increased with hydration time, silica fume addition of 10% can satisfy the requirement of detoxification for heavy metals investigated in terms of the identification standard of hazardous waste of China.

  20. Stabilization of heavy metals in MSWI fly ash using silica fume

    Highlights: • The stabilization of heavy metals in MSWI fly ash was investigated. • The addition of silica fume effectively reduced the leaching of Pb and Cd. • The relation of solid phase transformation and leaching behavior of heavy metals was discussed. - Abstract: The objective of this work was to investigate the feasibility and effectiveness of silica fume on stabilizing heavy metals in municipal solid waste incineration (MSWI) fly ash. In addition to compressive strength measurements, hydrated pastes were characterized by X-ray diffraction (XRD), thermal-analyses (DTA/TG), and MAS NMR (27Al and 29Si) techniques. It was found that silica fume additions could effectively reduce the leaching of toxic heavy metals. At the addition of 20% silica fume, leaching concentrations for Cu, Pb and Zn of the hydrated paste cured for 7 days decreased from 0.32 mg/L to 0.05 mg/L, 40.99 mg/L to 4.40 mg/L, and 6.96 mg/L to 0.21 mg/L compared with the MSWI fly ash. After curing for 135 days, Cd and Pb in the leachates were not detected, while Cu and Zn concentrations decreased to 0.02 mg/L and 0.03 mg/L. The speciation of Pb and Cd by the modified version of the European Community Bureau of Reference (BCR) extractions showed that these metals converted into more stable state in hydrated pastes of MSWI fly ash in the presence of silica fume. Although exchangeable and weak-acid soluble fractions of Cu and Zn increased with hydration time, silica fume addition of 10% can satisfy the requirement of detoxification for heavy metals investigated in terms of the identification standard of hazardous waste of China

  1. Study on Strength Development of High Strength Concrete Containing Fly ash and Silica fume

    A R Hariharan,; A S Santhi,; G Mohan Ganesh

    2011-01-01

    This paper presents the results of an experimental investigation carried out to evaluate the compressive strength of High Strength Concrete. High Strength Concrete is made by partial replacement of cement by fly ash (FA) and silica fume (SF). In this study the Class C fly ash used in various proportions 30%, 40% and 50% and that of silica fume by 6% and 10% by weight of cement. The mix proportions of concrete had a constant water binder ratio of 0.4 and super plasticizer was added based on th...

  2. Fracture Properties of Polypropylene Fiber Reinforced Concrete Containing Fly Ash and Silica Fume

    Qingfu Li; Peng Zhang

    2013-01-01

    A parametric experimental study has been conducted to investigate the effect of polypropylene fiber on the fracture properties of concrete containing fly ash and silica fume, with five fiber volume fraction (0.04, 0.06, 0.08, 0.1 and 0.12%) used. The results indicate that the addition of polypropylene fiber has greatly improved the fracture parameters of concrete composite containing 15% fly ash and 6% silica fume, such as fracture toughness, fracture energy, effective crack length, maximum m...

  3. New Asphalt Fume Generator : Development of an Original Sequential Mixing and Sampling Protocol

    VIRANAIKEN, Valérie; Gaudefroy, Vincent; LECOUTALLER, Patricia; DEYGOUT, François; Bujoli, Bruno

    2010-01-01

    At a time when regulations are becoming stricter in order to control and limit occupational exposure to pollutant emissions, the road industry is no exception to this trend. One of the main pollutant sources for road workers, and the subject of several studies, is the emission of fumes by Hot Mix Asphalt (HMA) and Warm Mix Asphalt (WMA) at plants and on road sites. Whereas the previous studies concerning this topic have focused on bitumen fumes, the Laboratoire Central des Ponts et Chaussé...

  4. Autogenous Deformation and Change of the Relative Humidity in Silica Fume-Modified Cement Paste

    Jensen, Ole mejlhede; Hansen, Per Freiesleben

    1996-01-01

    Even during sealed curing and at a constant temperature a hardening cement paste will deform and the relative humidity within its pores will lower. This autogenous deformation and autogenous relative humidity change may be so significant that the cement paste cracks if the deformation is restrained....... This article focuses on the influence of silica fume addition on autogenous deformation and autogenous relative humidity change. Continuous measurement of autogenous deformation and autogenous relative humidity change for more than 1 year and 1« years, respectively, was performed. The investigations...... show thatsilica fume addition markedly increases the autogenous shrinkage as well as the autogenous relative humidity change....

  5. Dynamic Moisture Sorption and Desorption in Fumed Silica-filled Silicone Foam

    Trautschold, Olivia Carol [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-02

    Characterizing dynamic moisture sorption and desorption in fumed silica-filled silicone foam is necessary for determining material compatibilities and life predictions, particularly in sealed environments that may be exposed to a range of environmental conditions. Thermogravimetric analysis (TGA) and near infrared spectroscopy (NIR) were performed on S5470 fumed silica-filled silicone foam to determine the weight percent of moisture at saturation. Additionally, TGA was used to determine the time, temperature, and relative humidity levels required for sorption and desorption of physisorbed moisture in S5470.

  6. Transport and Deposition of Welding Fume Agglomerates in a Realistic Human Nasal Airway.

    Tian, Lin; Inthavong, Kiao; Lidén, Göran; Shang, Yidan; Tu, Jiyuan

    2016-07-01

    Welding fume is a complex mixture containing ultra-fine particles in the nanometer range. Rather than being in the form of a singular sphere, due to the high particle concentration, welding fume particles agglomerate into long straight chains, branches, or other forms of compact shapes. Understanding the transport and deposition of these nano-agglomerates in human respiratory systems is of great interest as welding fumes are a known health hazard. The neurotoxin manganese (Mn) is a common element in welding fumes. Particulate Mn, either as soluble salts or oxides, that has deposited on the olfactory mucosa in human nasal airway is transported along the olfactory nerve to the olfactory bulb within the brain. If this Mn is further transported to the basal ganglia of the brain, it could accumulate at the part of the brain that is the focal point of its neurotoxicity. Accounting for various dynamic shape factors due to particle agglomeration, the current computational study is focused on the exposure route, the deposition pattern, and the deposition efficiency of the inhaled welding fume particles in a realistic human nasal cavity. Particular attention is given to the deposition pattern and deposition efficiency of inhaled welding fume agglomerates in the nasal olfactory region. For particles in the nanoscale, molecular diffusion is the dominant transport mechanism. Therefore, Brownian diffusion, hydrodynamic drag, Saffman lift force, and gravitational force are included in the model study. The deposition efficiencies for single spherical particles, two kinds of agglomerates of primary particles, two-dimensional planar and straight chains, are investigated for a range of primary particle sizes and a range of number of primary particles per agglomerate. A small fraction of the inhaled welding fume agglomerates is deposited on the olfactory mucosa, approximately in the range 0.1-1%, and depends on particle size and morphology. The strong size dependence of the deposition

  7. Phase analysis of fume during arc weld brazing of steel sheets with protective coatings

    J. Matusiak

    2016-04-01

    Full Text Available The article presents the results of research of the phase identification and of the quantitative phase analysis of fume generated during Cold Metal Transfer (CMT, ColdArc and Metal Inert Gas / Metal Active Gas (MIG / MAG weld brazing. Investigations were conducted for hot - dip coated steel sheets with zinc (Zn and zinc-iron (Zn - Fe alloy coatings. Arc shielding gases applied during the research-related tests were Ar + O2, Ar + CO2, Ar + H2 and Ar + CO2 + H2 gas mixtures. The analysis of the results covers the influence of the chemical composition of shielding gas on the chemical composition of welding fume.

  8. Influence of FAME addition to diesel fuel on exhaust fumes opacity of diesel engine

    G. Zając

    2008-06-01

    Full Text Available The work presents the results of research on the influence of the addition of rapeseed oil fatty acid methyl esters (FAME to diesel oil, in the quantity of 1-5% by volume, on exhaust fumes opacity of a diesel engine powered by such fuel. The research employed rapeseed oil FAME the additive. The results obtained proved that the use of FAME and methyl esters as an additive to diesel fuel (DF in the quantity of 5% causes a reduction of exhaust fumes opacity of diesel engine.

  9. A comparative study for radiological decontamination of laboratory fume hood materials.

    Thomas, Elizabeth; Sweet, Lucas; MacFarlan, Paul; McNamara, Bruce; Kerschner, Harrison

    2012-08-01

    The efficacy for radiological decontamination of the laboratory standard fume hood as constructed of stainless steel, compared to that of powder-coated carbon steel is described. While the chemical inertness of powder-coated surfaces is good, faced with everyday abrasion, aggressive inorganic solutions and vapors, and penetrating organics commonly employed in government laboratory fume hoods, radiological decontamination of powder-coated steel surfaces was found to be similar to those made of stainless steel for easily solubilized or digestible radionuclides. Plutonium was difficult to remove from stainless steel and powder-coated surfaces, especially after prolonged contact times. PMID:22739967

  10. Contacting cadmium deposition from spent industrial solutions

    Cadmium metal deposition from spent industrial solutions by cadmium (2) reduction with dispersed aluminium is studied. The influence of temperature, reagent concentration and the presence of complexing agents on the yield and purity of isolated cadmium metal is examined

  11. Metallothionein protection of cadmium toxicity

    The discovery of the cadmium (Cd)-binding protein from horse kidney in 1957 marked the birth of research on this low-molecular weight, cysteine-rich protein called metallothionein (MT) in Cd toxicology. MT plays minimal roles in the gastrointestinal absorption of Cd, but MT plays important roles in Cd retention in tissues and dramatically decreases biliary excretion of Cd. Cd-bound to MT is responsible for Cd accumulation in tissues and the long biological half-life of Cd in the body. Induction of MT protects against acute Cd-induced lethality, as well as acute toxicity to the liver and lung. Intracellular MT also plays important roles in ameliorating Cd toxicity following prolonged exposures, particularly chronic Cd-induced nephrotoxicity, osteotoxicity, and toxicity to the lung, liver, and immune system. There is an association between human and rodent Cd exposure and prostate cancers, especially in the portions where MT is poorly expressed. MT expression in Cd-induced tumors varies depending on the type and the stage of tumor development. For instance, high levels of MT are detected in Cd-induced sarcomas at the injection site, whereas the sarcoma metastases are devoid of MT. The use of MT-transgenic and MT-null mice has greatly helped define the role of MT in Cd toxicology, with the MT-null mice being hypersensitive and MT-transgenic mice resistant to Cd toxicity. Thus, MT is critical for protecting human health from Cd toxicity. There are large individual variations in MT expression, which might in turn predispose some people to Cd toxicity.

  12. Implication of cytochrome P-450 1A isoforms and the AH receptor in the genotoxicity of coal-tar fume condensate and bitumen fume condensates.

    Genevois, C; Pfohl-Leszkowicz, A; Boillot, K; Brandt, H; Castegnaro, M

    1998-06-01

    During the hot application of bitumen- or coal-tar-containing materials, fumes are emitted that contain polycyclic aromatic compounds. Although workers' exposure to these fumes is low, it might lead to health problems. No study has reported the metabolic pathways involved in the genotoxicity of coal tar or bitumen fume condensates (CTFC, BFCs). We have therefore studied the DNA adducts formed by incubation of CTFC or BFCs with liver microsomes from several type of mice and with yeast microsomes expressing individual human CYP enzymes. Our results demonstrates that: (1) the aryl hydrocarbon receptor (AHR) plays an important role in the biotransformation of BFCs and to a lesser extent of CTFC; (2) for CTFC, both cytochrome P450 (CYP) 1A isoforms are involved in the formation of genotoxic compounds, and the reactive metabolites formed via CYP 1A1, are substrates for epoxide hydrolase (mEH); (3) for BFCs, the genotoxicity is partially dependent upon CYP 1A1 and the reactive metabolites are not substrates for mEH; (4) CYP 1A isoforms are not exclusively responsible for the genotoxicity of the CTFC and BFCs as other CYPs and also enzymes of the [AH] gene battery, may play an important role. PMID:21781875

  13. Cadmium in Sweden - environmental risks

    Parkman, H.; Iverfeldt, Aa. [Swedish Environmental Research Inst. (Sweden); Borg, H.; Lithner, G. [Stockholm Univ. (Sweden). Inst. for Applied Environmental Research

    1998-03-01

    This report aims at assessing possible effects of cadmium in the Swedish environment. Swedish soils and soft freshwater systems are, due to a generally poor buffering capacity, severely affected by acidification. In addition, the low salinity in the Baltic Sea imply a naturally poor organism structure, with some important organisms living close to their limit of physiological tolerance. Cadmium in soils is mobilized at low pH, and the availability and toxicity of cadmium in marine systems are enhanced at low salinity. The Swedish environment is therefore extra vulnerable to cadmium pollution. The average concentrations of cadmium in the forest mor layers, agricultural soils, and fresh-waters in Sweden are enhanced compared to `back-ground concentrations`, with a general increasing trend from the north to the south-west, indicating strong impact of atmospheric deposition of cadmium originating from the central parts of Europe. In Swedish sea water, total cadmium concentrations, and the fraction of bio-available `free` cadmium, generally increases with decreasing salinity. Decreased emissions of cadmium to the environment have led to decreasing atmospheric deposition during the last decade. The net accumulation of cadmium in the forest mor layer has stopped, and even started to decrease. In northern Sweden, this is due to the decreased deposition, but in southern Sweden the main reason is increased leakage of cadmium from the topsoil as a consequence of acidification. As a result, cadmium in the Swedish environments is undergoing an extended redistribution between different soil compartments, and from the soils to the aquatic systems. 90 refs, 23 figs, 2 tabs. With 3 page summary in Swedish

  14. Experimental study, in rat wistar, of cadmium distribution and elimination as a function of administration route. Cadmium 109 maximum permissible concentration

    The absorption and the elimination of cadmium have been investigated in rats wistar after oral administration or after inhalation. Before studying gastro-intestinal absorption, it appeared necessary to precise acute toxicity of orally administred cadmium. The distribution of cadmium within organes was determined following a single or multiple oral doses, and we specially studied retention of a Cd dose ingested after several weeks of treatment with Cd-Acetate. Pulmonary and gastro-intestinal absorption of cadmium after ihalation of Cd-microparticles were studied. Data obtained from these studies on rats and extrapolated to man were used to calculate mximum permissible concentration (M.P.C.) of Cd-109 in water and in air

  15. The use of high expansion foam in the control of sodium and other fumes

    The uses of high expansion air foam for removing sodium fume and airborne radioactivity is discussed. Experiments are described which indicate that a high rate of removal of air contamination can be expected by encapsulation in a high expansion foam of low stability. (author)

  16. The effect of phenyl modified fumed silica on radiation resistance of silicone rubber

    Highlights: → Three kinds of phenyl modified fumed silica are prepared. → Phenyl modified fumed silica are used as reinforcing filler for silicone rubber. → This is a novel effective way to improve radiation resistance of silicone rubber. - Abstract: Three kinds of treated fumed silica were prepared with methylphenyldimethoxysilane (MPHTS), diphenyldiethoxysilane (DPHTS), and phenyltriethoxysilane (PHTS) as treating agents, respectively, and characterized by N2 adsorption, diffuse reflectance ultraviolet-vis spectra (DRUVS), titration and element analyzer. The results show that compared with untreated silica there are less surface hydroxyl groups retained on the treated silica, and the phenyl groups are introduced onto the silica surface. The treated silica was used as reinforcing filler for silicone rubber to investigate the resistance to irradiation of the silicone rubber obtained thereout. The mechanical properties and the average molecular weight between crosslinking points (Mc) of the silicone rubber were measured before and after irradiation. The dynamical mechanical properties of the silicone rubber were evaluated by dynamic mechanical analysis (DMA) before and after irradiation. It was found that the treated fumed silica cannot only effectively improve the radiation resistance of silicone rubber but also has excellent reinforcing effect on silicone rubber.

  17. Urinary fluoride concentration as an estimator of welding fume exposure from basic electrodes.

    Sjörgren, B; Hedström, L; Lindstedt, G.

    1984-01-01

    Urinary fluoride concentrations have been measured in electric arc welders using basic electrodes. The fluoride concentration and the total welding fume concentration in air showed a linear relation with postshift urinary fluoride concentration. The measured concentrations were below internationally recommended postshift urinary fluoride concentrations believed to cause fluorosis. Biological monitoring by postshift urinary fluoride measurements is evaluated for the prediction of total welding...

  18. Suppression in lung defense responses after bacterial infection in rats pretreated with different welding fumes

    Epidemiology suggests that inhalation of welding fumes increases the susceptibility to lung infection. The effects of chemically distinct welding fumes on lung defense responses after bacterial infection were compared. Fume was collected during gas metal arc (GMA) or flux-covered manual metal arc (MMA) welding using two consumable electrodes: stainless steel (SS) or mild steel (MS). The fumes were separated into water-soluble and -insoluble fractions. The GMA-SS and GMA-MS fumes were found to be relatively insoluble, whereas the MMA-SS was highly water soluble, with the soluble fraction comprised of 87% Cr and 11% Mn. On day 0, male Sprague-Dawley rats were intratracheally instilled with saline (vehicle control) or the different welding fumes (0.1 or 2 mg/rat). At day 3, the rats were intratracheally inoculated with 5 x 103 Listeria monocytogenes. On days 6, 8, and 10, left lungs were removed, homogenized, cultured overnight, and colony-forming units were counted to assess pulmonary bacterial clearance. Bronchoalveolar lavage (BAL) was performed on right lungs to recover phagocytes and BAL fluid to measure the production of nitric oxide (NO) and immunomodulatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin (IL)-2, IL-6, and IL-10. In contrast to the GMA-SS, GMA-MS, and saline groups, pretreatment with the highly water soluble MMA-SS fume caused significant body weight loss, extensive lung damage, and a dramatic reduction in pulmonary clearance of L. monocytogenes after infection. NO concentrations in BAL fluid and lung immunostaining of inducible NO synthase were dramatically increased in rats pretreated with MMA-SS before and after infection. MMA-SS treatment caused a significant decrease in IL-2 and significant increases in TNF-α, IL-6, and IL-10 after infection. In conclusion, pretreatment with MMA-SS increased production of NO and proinflammatory cytokines (TNF-α and IL-6) after infection, which are likely responsible for the elevation

  19. Cadmium sulfite hexahydrate revisited

    Sergio Baggio

    2008-07-01

    Full Text Available The present structural revision of the title compound, tetracadmium tetrasulfite hexahydrate, [Cd4(SO34(H2O5]·H2O, is a low-temperature upgrade (T = 100 K and R = 0.017 of the original room-temperature structure reported by Kiers & Vos [Cryst. Struct. Commun. (1978. 7, 399–403; T = 293 K and R = 0.080. The compound is a three-dimensional polymer with four independent cadmium centres, four sulfite anions and six water molecules, five of them coordinated to two cadmium centres and the remaining one an unbound solvent molecule which completes the asymmetric unit. There are two types of cadmium environment: CdO8 (through four chelating sulfite ligands and CdO6 (by way of six monocoordinated ligands. The former groups form planar arrays [parallel to (001 and separated by half a unit cell translation along c], made up of chains running along [110] and [overline{1}10], respectively. These chains are, in turn, interconnected both in an intraplanar as well as in an interplanar fashion by the latter CdO6 polyhedra into a tight three-dimensional framework. There is, in addition, an extensive network of hydrogen bonds, in which all 12 water H atoms act as donors and eight O atoms from all four sulfite groups and two water molecules act as acceptors.

  20. Crosslinkable fumed silica-based nanocomposite electrolytes for rechargeable lithium batteries

    Li, Yangxing; Yerian, Jeffrey A.; Khan, Saad A.; Fedkiw, Peter S. [Department of Chemical & amp; Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695-7905 (United States)

    2006-10-27

    Electrochemical and rheological properties are reported of composite polymer electrolytes (CPEs) consisting of dual-functionalized fumed silica with methacrylate and octyl groups+low-molecular weight poly(ethylene glycol) dimethyl ether (PEGdm)+lithium bis(trifluoromethanesulfonyl)imide (LiTFSI, lithium imide)+butyl methacrylate (BMA). The role of butyl methacrylate, which aids in formation of a crosslinked network by tethering adjacent fumed silica particles, on rheology and electrochemistry is examined together with the effects of fumed silica surface group, fumed silica weight percent, salt concentration, and solvent molecular weight. Chemical crosslinking of the fumed silica with 20% BMA shows a substantial increase in the elastic modulus of the system and a transition from a liquid-like/flocculated state to an elastic network. In contrast, no change in lithium transference number and only a modest decrease (factor of 2) on conductivity of the CPE are observed, indicating that a crosslinked silica network has minimal effect on the mechanism of ionic transport. These trends suggest that the chemical crosslinks occur on a microscopic scale, as opposed to a molecular scale, between adjacent silica particles and therefore do not impede the segmental mobility of the PEGdm. The relative proportion of the methacrylate and octyl groups on the silica surface displays a nominal effect on both rheology and conductivity following crosslinking although the pre-cure rheology is a function of the surface groups. Chemical crosslinked nanocomposite polymer electrolytes offer significant higher elastic modulus and yield stress than the physical nanocomposite counterpart with a small/negligible penalty of transport properties. The crosslinked CPEs exhibit good interfacial stability with lithium metal at open circuit, however, they perform poorly in cycling of lithium-lithium cells. (author)

  1. Effects on the efficiency of activated carbon on exposure to welding fumes

    Ghosh, D. [Southern Company Services, Inc., Birmingham, AL (United States)

    1995-02-01

    It is the intention of this paper to document that certain types of welding fumes have little or no effect on the effectiveness of the carbon filter air filtration efficiency when directly exposed to a controlled amount of welding fumes for a short-term period. The welding processes studied were restricted to shielded metal arc welding (SMAW), flux cored arc welding (FCAW), gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) processes. Contrary to the SMAW and FCAW processes, the GTAW (or TIG) and the GMAW (or MIG) welding processes do not require the use of flux as part of the overall process. Credit was taken for these processes occurring in inert gas environments and producing minimal amount of smoke. It was concluded that a study involving the SMAW process would also envelop the effects of the TIG and MIG welding processes. The quantity of welding fumes generated during the arc welding process is a function of the particular process, the size and type of electrode, welding machine amperage, and operator proficiency. For this study, the amount of welding for specific testing was equated to the amount of welding normally conducted during plant unit outages. Different welding electrodes were also evaluated, and the subsequent testing was limited to an E7018 electrode which was judged to be representative of all carbon and stainless steel electrodes commonly used at the site. The effect of welding fumes on activated charcoal was tested using a filtration unit complete with prefilters, upstream and downstream high efficiency particulate air (HEPA) filters, and a carbon adsorber section. The complete system was field tested in accordance with ANSI N510 standards prior to exposing the filters and the adsorber bed to welding fumes. The carbon samples were tested at an established laboratory using ASTM D3803-1989 standards.

  2. Airborne nanoparticle exposures associated with the manual handling of nanoalumina and nanosilver in fume hoods

    Manual handling of nanoparticles is a fundamental task of most nanomaterial research; such handling may expose workers to ultrafine or nanoparticles. Recent studies confirm that exposures to ultrafine or nanoparticles produce adverse inflammatory responses in rodent lungs and such particles may translocate to other areas of the body, including the brain. An important method for protecting workers handling nanoparticles from exposure to airborne nanoparticles is the laboratory fume hood. Such hoods rely on the proper face velocity for optimum performance. In addition, several other hood design and operating factors can affect worker exposure. Handling experiments were performed to measure airborne particle concentration while handling nanoparticles in three fume hoods located in different buildings under a range of operating conditions. Nanoalumina and nanosilver were selected to perform handling experiments in the fume hoods. Air samples were also collected on polycarbonate membrane filters and particles were characterized by scanning electron microscopy. Handling tasks included transferring particles from beaker to beaker by spatula and by pouring. Measurement locations were the room background, the researcher's breathing zone and upstream and downstream from the handling location. Variable factors studied included hood design, transfer method, face velocity/sash location and material types. Airborne particle concentrations measured at breathing zone locations were analyzed to characterize exposure level. Statistics were used to test the correlation between data. The test results found that the handling of dry powders consisting of nano-sized particles inside laboratory fume hoods can result in a significant release of airborne nanoparticles from the fume hood into the laboratory environment and the researcher's breathing zone. Many variables were found to affect the extent of particle release including hood design, hood operation (sash height, face velocity

  3. Characterization of Tungsten Inert Gas (TIG) Welding Fume Generated by Apprentice Welders.

    Graczyk, Halshka; Lewinski, Nastassja; Zhao, Jiayuan; Concha-Lozano, Nicolas; Riediker, Michael

    2016-03-01

    Tungsten inert gas welding (TIG) represents one of the most widely used metal joining processes in industry. Its propensity to generate a greater portion of welding fume particles at the nanoscale poses a potential occupational health hazard for workers. However, current literature lacks comprehensive characterization of TIG welding fume particles. Even less is known about welding fumes generated by welding apprentices with little experience in welding. We characterized TIG welding fume generated by apprentice welders (N = 20) in a ventilated exposure cabin. Exposure assessment was conducted for each apprentice welder at the breathing zone (BZ) inside of the welding helmet and at a near-field (NF) location, 60cm away from the welding task. We characterized particulate matter (PM4), particle number concentration and particle size, particle morphology, chemical composition, reactive oxygen species (ROS) production potential, and gaseous components. The mean particle number concentration at the BZ was 1.69E+06 particles cm(-3), with a mean geometric mean diameter of 45nm. On average across all subjects, 92% of the particle counts at the BZ were below 100nm. We observed elevated concentrations of tungsten, which was most likely due to electrode consumption. Mean ROS production potential of TIG welding fumes at the BZ exceeded average concentrations previously found in traffic-polluted air. Furthermore, ROS production potential was significantly higher for apprentices that burned their metal during their welding task. We recommend that future exposure assessments take into consideration welding performance as a potential exposure modifier for apprentice welders or welders with minimal training. PMID:26464505

  4. Effect of plasticizer and fumed silica on ionic conductivity behaviour of proton conducting polymer electrolytes containing HPF6

    Jitender Paul Sharma; S S Sekhon

    2013-08-01

    The effect of addition of propylene carbonate (PC) and nano-sized fumed silica on the ionic conductivity behaviour of proton conducting polymer electrolytes containing different concentrations of hexafluorophosphoric acid (HPF6) in polyethylene oxide (PEO) has been studied. The addition of PC results in an increase in ionic conductivity, whereas the addition of nano-sized fumed silica improves mechanical strength of electrolytes along with a small increase in ionic conductivity. It was observed that the simultaneous addition of PC and fumed silica results in electrolytes with optimum value of ionic conductivity and other properties.

  5. Relation between various chromium compounds and some other elements in fumes from manual metal arc stainless steel welding.

    Matczak, W; Chmielnicka, J

    1993-01-01

    For the years 1987-1990 160 individual samples of manual metal arc stainless steel (MMA/SS) welding fumes from the breathing zone of welders in four industrial plants were collected. Concentrations of soluble and insoluble chromium (Cr) III and Cr VI compounds as well as of some other welding fume elements (Fe, Mn, Ni, F) were determined. Concentration of welding fumes in the breathing zone ranged from 0.2 to 23.4 mg/m3. Total Cr amounted to 0.005-0.991 mg/m3 (including 0.005-0.842 mg/m3 Cr V...

  6. Cadmium in blood and hypertension

    Eum, Ki-Do; Lee, Mi-Sun [Department of Environmental Health, Graduate School of Public Health and Institute of Health and Environment, Seoul National University, Seoul (Korea, Republic of); Paek, Domyung [Department of Environmental Health, Graduate School of Public Health and Institute of Health and Environment, Seoul National University, Seoul (Korea, Republic of)], E-mail: paekdm@snu.ac.kr

    2008-12-15

    Objectives:: This study is to examine the effect of cadmium exposure on blood pressure in Korean general population. Methods:: The study population consisted of 958 men and 944 women who participated in the 2005 Korean National Health and Nutrition Examination Survey (KNHANES), in which blood pressure and blood cadmium were measured from each participant. Results:: The mean blood cadmium level was 1.67 {mu}g/L (median level 1.55). The prevalence of hypertension was 26.2%. The blood cadmium level was significantly higher among those subjects with hypertension than those without (mean level 1.77 versus 1.64 {mu}g/dL). After adjusting for covariates, the odds ratio of hypertension comparing the highest to the lowest tertile of cadmium in blood was 1.51 (95% confidence interval 1.13 to 2.05), and a dose-response relationship was observed. Systolic, diastolic, and mean arterial blood pressure were all positively associated with blood cadmium level, and this effect of cadmium on blood pressure was markedly stronger when the kidney function was reduced. Conclusions:: Cadmium exposures at the current level may have increased the blood pressure of Korean general population.

  7. Cadmium in blood and hypertension

    Objectives:: This study is to examine the effect of cadmium exposure on blood pressure in Korean general population. Methods:: The study population consisted of 958 men and 944 women who participated in the 2005 Korean National Health and Nutrition Examination Survey (KNHANES), in which blood pressure and blood cadmium were measured from each participant. Results:: The mean blood cadmium level was 1.67 μg/L (median level 1.55). The prevalence of hypertension was 26.2%. The blood cadmium level was significantly higher among those subjects with hypertension than those without (mean level 1.77 versus 1.64 μg/dL). After adjusting for covariates, the odds ratio of hypertension comparing the highest to the lowest tertile of cadmium in blood was 1.51 (95% confidence interval 1.13 to 2.05), and a dose-response relationship was observed. Systolic, diastolic, and mean arterial blood pressure were all positively associated with blood cadmium level, and this effect of cadmium on blood pressure was markedly stronger when the kidney function was reduced. Conclusions:: Cadmium exposures at the current level may have increased the blood pressure of Korean general population

  8. Projectbeschrijving Cadmium-informatiepunt (CIP)

    Meijer PJ

    1989-01-01

    To minimize the use of cadmium the Central Government has decided to perform the purchase of products and materials within the Central Government as much as possible within the Draft Cadmium Decree. The activities to achieve this are as far as could be seen at the start of the project in june 1989, mentioned in this report.

  9. 29 CFR 1926.1127 - Cadmium.

    2010-07-01

    ... containment of cadmium or materials containing cadmium on the site or location at which construction...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Toxic and Hazardous Substances § 1926.1127 Cadmium. (a... forms, in all construction work where an employee may potentially be exposed to cadmium....

  10. Cadmium exposure in the Swedish environment

    NONE

    1998-03-01

    This report gives a thorough description of cadmium in the Swedish environment. It comprises three parts: Cadmium in Sweden - environmental risks;, Cadmium in goods - contribution to environmental exposure;, and Cadmium in fertilizers, soil, crops and foods - the Swedish situation. Separate abstracts have been prepared for all three parts

  11. The Study Of Histopathological Effects Of Welding Fumes On Spermatogenesis In Rat

    Arab M R

    2005-07-01

    Full Text Available Background: Fumes generated during electric welding are one of air pollutants of working place in industrial companies, which can cause some clinical signs and diseases in worker, including mucosal irritation, changing of semen quality and cancer. Chronic exposure of workers with these fumes can cause reduce sperm motility and forward penetration and decrease in normal sperm count. Although a lot of researches were done in this field up to now, there is little information about histopathological effects of these fumes on germinal epithelium. The aim of this study was to identify structural changes of germinal epithelium in Rat as an experimental model after exposure to fumes of electric welding in exposure chamber. Material and Methods: A total number of 60 Sprague Dawley Rats were chosen and divided into experimental (40 and control (20 groups. Each of groups was subdivided into 2, 4, 6 and 8-week subgroups. The number of Rat in each subgroup of experimental and control group was 10 and 5 respectively. Animals were housed in standard situation. After adaptation experimental group were exposed to fumes of electric welding (AMA 2000 electrode, 100 Ampere, 0.1 cm/s speed of electrode welding for 2 hour/day and 5 day/week. The rate of air turn over in exposure chamber was fixed to 12-15/hour. The amount of O3, CO, CO2, NO + NO2 and particulate matter were measured by Galtec detectors and Cellulose acetate filter respectively. According to time table animals were killed and specimens from testis were taken and fixed in formaline buffer solution and processed routinely. Sections with 5-7 micrometer in thickness were stained by H-E, PAS, PNA and Alcian blue pH=2.5. The thickness of germinal epithelium was measured and data were analyzed by Kruskall Wallis test. Results: The results of this study showed a few quantitative and qualitative changes in germinal epithelium. Vasodilatation of vessels in tunica albuginea and interstitial tissue, decreasing of

  12. Cadmium in newborns

    Eklund, Gunilla

    2003-01-01

    Cadmium (Cd) is a well-known nephrotoxic environmental contaminant but there are indications that the developing nervous system might be even more sensitive to Cd than the kidneys in adults. Infants are exposed to Cd from various formulas and infant diets and the gastrointestinal Cd uptake is believed to be higher in newborns than in adults. Cd levels monitored in infant foods ranged between 0.74 and 27.0 µg/kg. Cow's milk formulas had the lowest levels and cereal-based formulas had up to 21 ...

  13. Cadmium sulfite hexahydrate revisited

    Sergio Baggio; Andrés Ibáñez; Ricardo Baggio

    2008-01-01

    The present structural revision of the title compound, tetracadmium tetrasulfite hexahydrate, [Cd4(SO3)4(H2O)5]·H2O, is a low-temperature upgrade (T = 100 K and R = 0.017) of the original room-temperature structure reported by Kiers & Vos [Cryst. Struct. Commun. (1978). 7, 399–403; T = 293 K and R = 0.080). The compound is a three-dimensional polymer with four independent cadmium centres, four sulfite anions and six water molecules, five of them coordinated to two c...

  14. Cadmium and zinc

    Cadmium and zinc are naturally occurring trace metals that are often considered together because of their close geochemical association and similarities in chemical reactivity. The loss of two electrons from an atom of Cd or Zn imparts to each an electron configuration with completely filled d orbitals; this results in a highly stable 2/sup +/ oxidation state. But Cd and Zn differ greatly in their significance to biological systems. Whereas Zn is an essential nutrient for plants, animals, and humans, Cd is best known for its toxicity to plants and as a causative agent of several disease syndromes in animals and humans

  15. Properties of silica fume procured from natural diatomite and its usage in the production of vacuum insulation panels

    V.P. Selyaev

    2013-11-01

    Full Text Available The article shows the results of the research of silica fume particles procured from diatomite from Atemar deposit by means of separating silicic acid from colloidal dissolved state into the sediment. The objective of the work was to define thermal-physical and structural characteristics of the silica fume. The research included IR-spectrometry, granulometry, thermal gravimetric analysis, X-ray structural analysis, optical microscopy, and small angle X-Ray scattering. As a result of the research, the silica fume was defined to predominantly consist of amorphous silicon dioxide and had the developed pore structure of particles. A large number of nanosized particles and pores decreases heat transmission and increases reactive capability, that gives opportunity of using the powder silica fume as an active agent in dry mixes and concrete composites, as a component of sponge-glass, and as a filler material in vacuum insulation panel.

  16. Effects of Cadmium on Phenolic Composition and Antioxidant Activities of Erica andevalensis

    Belén Márquez-García

    2012-01-01

    Full Text Available We evaluated the effects of cadmium on phenolic composition of Erica andevalensis, an endemic protected heather that grows in mine affected soils. Plants cultivated under laboratory-controlled conditions were exposed to acute doses of cadmium to investigate the mechanisms this species possesses to survive in the presence of toxic metals in its natural habitat. Cadmium increased the total levels of phenolics and flavonoids compounds, and the total antioxidant capacity. Cinnamic acid derivatives, epicatechin, and rutin were increased in the presence of cadmium when applied in levels that did not alter the ratio of chlorophylls. Phenolic compounds play an important role in the metabolism of E. andevalensis to survive in heavy metal polluted soils.

  17. Biomonitoring of cadmium in pig production

    Lindén, Anna

    2002-01-01

    Cadmium is a nephrotoxic metal with increasing levels in arable soils. The non-smoking population is exposed to cadmium mainly from vegetable food, especially cereal products. The major part of pig feed is cereals, and accumulated cadmium in pig kidney could reflect cadmium in the local agricultural environment. In this thesis, the possibility to use pig kidney as a bioindicator of the availability of cadmium in the agricultural environment was evaluated. There were significant correlations b...

  18. Properties of silica fume procured from natural diatomite and its usage in the production of vacuum insulation panels

    V.P. Selyaev; V.A. Neverov; O.G. Mashtaev; A.V. Kolotushkin

    2013-01-01

    The article shows the results of the research of silica fume particles procured from diatomite from Atemar deposit by means of separating silicic acid from colloidal dissolved state into the sediment. The objective of the work was to define thermal-physical and structural characteristics of the silica fume. The research included IR-spectrometry, granulometry, thermal gravimetric analysis, X-ray structural analysis, optical microscopy, and small angle X-Ray scattering. As a result of the resea...

  19. An Accelerated Test Method of Simultaneous Carbonation and Chloride Ion Ingress: Durability of Silica Fume Concrete in Severe Environments

    Ghahari, S. A.; Ramezanianpour, A. M.; Ramezanianpour, A. A.; Esmaeili, M

    2016-01-01

    The effects of simultaneous carbonation and chloride ion attack on mechanical characteristics and durability of concrete containing silica fume have been investigated through an accelerated test method. Specimens containing different amounts of silica fume were maintained in an apparatus in which carbon dioxide pressure and concentration and relative humidity were kept constant, and wetting and drying cycles in saline water were applied. Surface resistivity, sorptivity, CO2 consumption, and c...

  20. Silica Fume and Fly Ash Admixed Can Help to Improve the PRC Durability Combine Microscopic Analysis

    Xiao Li-guang

    2016-01-01

    Full Text Available Silica fume/Fly ash RPC can greatly improve durability. When Silica fume to replace the same amount of 8% of the proportion of cement, re-mixed 15min of mechanically activated Fly ash content of 10%, by chloride ion flux detector measuring, complex doped than the reference RPC impermeability improved significantly; In addition, by using static nitrogen adsorption method showed, RPC internal pore structure determination, the hole integral volume was lower than the reference admixed RPC integral pore volume significantly; And combined SEM microscopic experimental methods, mixed of RPC internal structure and the formation mechanism analysis showed that, SF/FA complex fully embodies the synergy doped composites “Synergistic” principle.

  1. Effect of Some Admixtures on the Hydration of Silica Fume and Hydrated Lime

    2000-01-01

    The effects of sodium salt of naphthalene formaldehyde sulfonic acid and stearic acid on the hydration of silica fume and Ca(0H)2 have been investigated. The hydration was carried out at 60℃ and W/S ratio of 4 for various time intervals namely, 1, 3, 7 and 28 days and in the presence of 0.2% and 5% superplasticizer and stearic acid. The results of the hydration kinetics show that both admixtures accelerate the hydration reaction of silica fume and calcium hydroxide during the first 7 days. Whereas, after 28 days hydration there is no significant effect. Generally, most of free calcium hydroxide seems to be consumed after 28 days. In addition, the phase composition as well as the microstructure of the formed hydrates was examined by using X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) respectively.

  2. STUDY ON DURABILITY PROPERTIES OF RECYCLED AGGREGATE CONCRETE INCORPORATED WITH S ILICA FUME AND MINERAL QUARTZ

    Anand K . Darji *; Dr. Indrajit N Patel,; Mrs. Jagruti Shah

    2015-01-01

    Disposal of construction waste is now new challenge for the construction industry in this era. This is peak time to use Construction waste as recycled aggregate (RA) in concrete manufacturing for sustainable development. Recycled aggregate concrete (RAC ) is the future to save environment from the waste. Supplementary Cementing Materials (SCMs) are widely used these days to improve the durability of c oncrete. Silica fume has gai...

  3. Effects of welding fumes on nuclear air cleaning system carbon adsorber banks

    Standard Technical Specifications for nuclear air cleaning systems include requirements for surveillance tests following fire, painting, or chemical release in areas communicating with the affected system. To conservatively implement this requirement, many plants categorize welding as a chemical release process, and institute controls to ensure that welding fumes do not interact with carbon adsorbers in a filter system. After reviewing research data that indicated welding had a minimal impact on adsorber iodine removal efficiency, further testing was performed with the goal of establishing a welding threshold. It was anticipated that some quantity of weld electrodes could be determined that had a corresponding detrimental impact on iodine removal efficiency for the exposed adsorber. This value could be used to determine a conservative sampling schedule that would allow the station to perform laboratory testing to ensure system degradation did not occur without a full battery of surveillance tests. A series of tests was designed to demonstrate carbon efficiency versus cumulative welding fume exposure. Three series of tests were performed, one for each of three different types of commonly used weld electrodes. Carbon sampling was performed at baseline conditions, and every five pounds of electrode thereafter. Two different laboratory tests were performed for each sample; one in accordance with ASTM 3803/1989 at 95% relative humidity and 30 degrees C, and another using the less rigorous conditions of 70% relative humidity and 80 degrees C. Review of the test data for all three types of electrodes failed to show a significant correlation between carbon efficiency degradation and welding fume exposure. Accordingly, welding is no longer categorized as a 'chemical release process' at McGuire Nuclear Station, and limits on welding fume interaction with ventilation systems have been eliminated. 4 refs., 3 figs., 1 tab

  4. Effects of lead pollution from vehicular exhaust fumes against sentinel juvenile Achatina achatina.

    Ebenso, I E; Ologhobo, A D

    2008-11-01

    We investigated lead metal pollution induced by traffic fumes along roads with differing traffic intensity near abandoned battery factory (Niger Delta, Nigeria). Juvenile Achatina achatina were positioned as sentinels in plastic snaileries 2 m on road sides. Lead contamination in snail tissue by atomic absorption spectrophotometer increased with increasing vehicular traffic intensity. Snails showed low positive (r (2) = 0.40) relationship and significant (p road sides are prone to lead contamination. PMID:18784896

  5. Pemanfaatan Batu Apung Dalam Pembuatan Beton Ringan Dengan Sikament-NN Dan Sika Fume

    Simanjuntak, Tianas

    2010-01-01

    Has been fabricated concrete made from cement, sand, pebbles, pumice, Sikament NN and Sika-Fume. With the treatment time: 7, 21 and 28 days. Testing parameters include: density, absorption, compressive strength, and permeability. The results show that lightweight concrete with the best composition variation variation of the ratio of pumice gravel is 100: 0, 80: 20, 60: 40, 40: 60, 20: 80, and 0: 100 (in% volume), and occurs in the mixture is 80% (volume) of gravel and 40% (volume) of pumice, ...

  6. In situ polymerization of L-Lactide in the presence of fumed silica

    Chemiorheology, i.e. rheological changes during the polymerization, of a biosourced monomer, i.e. L-Lactide, containing fumed silica have been studied. For that purpose, the reaction was proceeded in situ between the plates of a dynamic rheometer. The polymerization kinetics was followed from the variation of the complex shear modulus versus reaction time. Moreover, at temperatures lower than the crystallization temperature, it was possible to follow the crystallization process while the polymerization takes place. Adding fumed silica particles into the monomer leads to the formation of a physical (percolated) network from particle-particle interactions, i.e. silica, in the L-Lactide probably hydrophilic interactions. The gel-like structure was kept while the polymerization as long as the strain remains low indicating that the silica particle network remains weak. Furthermore, the mechanism of the break down of the gel structure under large deformation as well as the recovery was discussed. It seems that the non-linearity effect of the nanocomposites stems in the silica inter-particle interactions. It was found that silica particles do not have any effect on the temperature of crystallization - molar mass relation but could act as nucleating agent. In situ polymerization of L-Lactide in the presence of 5 wt.% of modified fumed silica was carried out in a reactor. It was found that fumed hydrophilic silica leaded to a microcomposite with highly dense agglomerates in the polymer matrix whereas with a less hydrophilic silica it was possible to decrease the size of the agglomerates increasing the dispersion. The finest dispersion state was achieved with the 'initiating' functionalized silica leading to a 'grafting from' polymerization of the L-Lactide. Such functionalized silica leads to a nanoscale dispersion in a one-step bulk polymerization with only a few small agglomerates.

  7. The effects of fumed silica and barite on the aluminum resistance of alumina castables

    Afshar, Saied; Gaubert, Christophe; Allaire, Claude

    2003-11-01

    A study of the effects of microsilica and barium sulfate as additives in high-tabular alumina castables on cold and hot modulus of rupture, porosity, thermal shock, and corrosion resistance to aluminum attack is reported in this article. This investigation underlined the importance of the quality of fumed silica on the physical and mechanical properties of refractory castables, and also confirmed the importance of celsian formation during firing in the protection of refractory against aluminum attack.

  8. Effect of silica fume additions on the hydration behaviour of calcium aluminates

    Fumo, Daniel A.; Segadães, Ana M.

    1997-01-01

    In the recent refractory castables technology, the calcium aluminate cement is being replaced in increasing proportion by very fine matrix components, such as silica fume and colloidal alumina. More efficient particle packing and the resulting lower water requirements have been the proposed explanation for the improved green density and strength, without sacrificing the castable workability. However, the aluminates are still responsible for the hydraulic setting of the castable. The hydration...

  9. Computational Fluid Dynamic Modeling of Zinc Slag Fuming Process in Top-Submerged Lance Smelting Furnace

    Huda, Nazmul; Naser, Jamal; Brooks, Geoffrey; Reuter, Markus A.; Matusewicz, Robert W.

    2012-02-01

    Slag fuming is a reductive treatment process for molten zinciferous slags for extracting zinc in the form of metal vapor by injecting or adding a reductant source such as pulverized coal or lump coal and natural gas. A computational fluid dynamic (CFD) model was developed to study the zinc slag fuming process from imperial smelting furnace (ISF) slag in a top-submerged lance furnace and to investigate the details of fluid flow, reaction kinetics, and heat transfer in the furnace. The model integrates combustion phenomena and chemical reactions with the heat, mass, and momentum interfacial interaction between the phases present in the system. A commercial CFD package AVL Fire 2009.2 (AVL, Graz, Austria) coupled with a number of user-defined subroutines in FORTRAN programming language were used to develop the model. The model is based on three-dimensional (3-D) Eulerian multiphase flow approach, and it predicts the velocity and temperature field of the molten slag bath, generated turbulence, and vortex and plume shape at the lance tip. The model also predicts the mass fractions of slag and gaseous components inside the furnace. The model predicted that the percent of ZnO in the slag bath decreases linearly with time and is consistent broadly with the experimental data. The zinc fuming rate from the slag bath predicted by the model was validated through macrostep validation process against the experimental study of Waladan et al. The model results predicted that the rate of ZnO reduction is controlled by the mass transfer of ZnO from the bulk slag to slag-gas interface and rate of gas-carbon reaction for the specified simulation time studied. Although the model is based on zinc slag fuming, the basic approach could be expanded or applied for the CFD analysis of analogous systems.

  10. Effects of welding fumes on nuclear air cleaning system carbon adsorber banks

    Roberson, P.W. [Duke Power Company, Huntersville, NC (United States)

    1997-08-01

    Standard Technical Specifications for nuclear air cleaning systems include requirements for surveillance tests following fire, painting, or chemical release in areas communicating with the affected system. To conservatively implement this requirement, many plants categorize welding as a chemical release process, and institute controls to ensure that welding fumes do not interact with carbon adsorbers in a filter system. After reviewing research data that indicated welding had a minimal impact on adsorber iodine removal efficiency, further testing was performed with the goal of establishing a welding threshold. It was anticipated that some quantity of weld electrodes could be determined that had a corresponding detrimental impact on iodine removal efficiency for the exposed adsorber. This value could be used to determine a conservative sampling schedule that would allow the station to perform laboratory testing to ensure system degradation did not occur without a full battery of surveillance tests. A series of tests was designed to demonstrate carbon efficiency versus cumulative welding fume exposure. Three series of tests were performed, one for each of three different types of commonly used weld electrodes. Carbon sampling was performed at baseline conditions, and every five pounds of electrode thereafter. Two different laboratory tests were performed for each sample; one in accordance with ASTM 3803/1989 at 95% relative humidity and 30 degrees C, and another using the less rigorous conditions of 70% relative humidity and 80 degrees C. Review of the test data for all three types of electrodes failed to show a significant correlation between carbon efficiency degradation and welding fume exposure. Accordingly, welding is no longer categorized as a `chemical release process` at McGuire Nuclear Station, and limits on welding fume interaction with ventilation systems have been eliminated. 4 refs., 3 figs., 1 tab.

  11. Characterization of the early pulmonary inflammatory response associated with PTFE fume exposure

    Johnston, C. J.; Finkelstein, J. N.; Gelein, R.; Baggs, R.; Oberdorster, G.; Clarkson, T. W. (Principal Investigator)

    1996-01-01

    Heating of polytetrafluoroethylene (PTFE) has been described to release fumes containing ultrafine particles (approximately 18 nm diam). These fumes can be highly toxic in the respiratory tract inducing extensive pulmonary edema with hemorrhagic inflammation. Fischer-344 rats were exposed to PTFE fumes generated by temperatures ranging from 450 to 460 degrees C for 15 min at an exposure concentration of 5 x 10(5) particles/cm3, equivalent to approximately 50 micrograms/m3. Responses were examined 4 hr post-treatment when these rats demonstrated 60-85% neutrophils (PMNs) in their lung lavage. Increases in abundance for messages encoding the antioxidants manganese superoxide dismutase and metallothionein (MT) increased 15- and 40-fold, respectively. For messages encoding the pro- and anti-inflammatory cytokines: inducible nitric oxide synthase, interleukin 1 alpha, 1 beta, and 6 (IL-1 alpha, IL-1 beta, and IL-6), macrophage inflammatory protein-2, and tumor necrosis factor-alpha (TNF alpha) increases of 5-, 5-, 10-, 40-, 40-, and 15-fold were present. Vascular endothelial growth factor, which may play a role in the integrity of the endothelial barrier, was decreased to 20% of controls. In situ sections were hybridized with 33P cRNA probes encoding IL-6, MT, surfactant protein C, and TNF alpha. Increased mRNA abundance for MT and IL-6 was expressed around all airways and interstitial regions with MT and IL-6 demonstrating similar spatial distribution. Large numbers of activated PMNs expressed IL-6, MT, and TNF alpha. Additionally, pulmonary macrophages and epithelial cells were actively involved. These observations support the notion that PTFE fumes containing ultrafine particles initiate a severe inflammatory response at low inhaled particle mass concentrations, which is suggestive of an oxidative injury. Furthermore, PMNs may actively regulate the inflammatory process through cytokine and antioxidant expression.

  12. 29 CFR 1926.55 - Gases, vapors, fumes, dusts, and mists.

    2010-07-01

    ... Nitrous oxide 10024-97-2 E Octachloronaphthalene 2234-13-1 — 0.1 X Octane 111-65-9 400 1900 — Oil mist... oxide fume 1309-37-1 — 10 — Iron salts (soluble) (as Fe) Varies with compound — 1 — Isoamyl acetate 123... Diphenyl Bisphenol A; see Diglycidyl ether Boron oxide 1303-86-2 Total dust — 15 — Boron tribromide...

  13. Composite polymer electrolytes using fumed silica fillers: synthesis, rheology and electrochemistry

    Khan, Saad A.; Fedkiw, Peter S.; Baker, Gregory L.

    1999-06-28

    The goal of the synthesis research was to devise routes to PEG/fumed silica/lithium salt composites that can be processed and then photochemically cross-linked to form mechanically stable electrolytes. An essential feature of the system is that the ionic conductivity and the mechanical properties must be de-coupled from each other, i.e., cross-linking of the fumed silica matrix must not cause a significant deterioration of the conductivity of the composite. As shown in Figure 2, we prepared a range of surface-modified fumed silicas and investigated their ability to form mechanically stable composite electrolytes. The groups used to modify the surface properties of the silica ranged from simple linear alkyls that render the silica hydrophobia to polyethers that promote compatibility with the electrolyte. From these materials we developed a cross-linkable system that satisfies the criteria of processibility and high-conductivity. The key material needed for the cross-linking reaction are silicas that bear surface-attached monomers. As shown schematically in Figure 3a, we prepared fumed silicas with a combination of surface groups, for example, an octyl chain with different coverages of tethered methacrylates. The length of the tether was varied, and we found that both C{sub 3} and C{sub 8} tethers gave useful composites. The functionalized silicas were combined with PEG-DM, AIBN or benzophenone (free radical initiators), LiClO{sub 4} or Li imide, and either methyl, butyl, or octyl, methacrylate to form stable clear gels. Upon irradiation with UV light, polymerization of both the tethered methacrylate and the added methacrylate took place, yielding a cross-linked rubbery composite material. Ionic conductivity measurements before and after cross-linking showed only a slight decrease (see Figure 9 later), thereby offering strong experimental evidence that the mechanical properties conferred by the silica matrix are de-coupled from the ionic conductivity of the PEG

  14. Comparison of Nanoparticle Exposures Between Fumed and Sol-gel Nano-silica Manufacturing Facilities

    OH, Sewan; KIM, Boowook; KIM, Hyunwook

    2014-01-01

    Silica nanoparticles (SNPs) are widely used all around the world and it is necessary to evaluate appropriate risk management measures. An initial step in this process is to assess worker exposures in their current situation. The objective of this study was to compare concentrations and morphologic characteristics of fumed (FS) and sol-gel silica nanoparticles (SS) in two manufacturing facilities. The number concentration (NC) and particle size were measured by a real-time instrument. Airborne...

  15. Comparison of Powder Dusting and Cyanoacrylate Fuming Techniques in Retrieving Latent Fingerprint Exposed to Environment Conditions

    Latent fingerprints are one of the best evidence to prove the presence of an individuals presence at the crime scene. There are many techniques available for a successful fingerprint lifting. Two of the most common ones are fingerprint powder dusting and cyanoacrylate fuming. This research aims to compare both techniques and determine which has a higher success rate in retrieving fingerprints exposed to local environmental conditions for three days. Fingerprint samples were collected from 18 subjects on glass, perspex and aluminium slides. These samples were then exposed to local environmental conditions for three days. The fingerprints were then developed using the aforementioned techniques. Based on the results, it can be safely said that, fuming results in clearer fingerprints and more minutiae can be found from the retrieved fingerprints even with exposure to less than optimum local conditions. This proves that fuming is a better fingerprint lifting method to resolve latent fingerprint compared to powder dusting. Surface on which the fingerprint is retrieved from influences the quality of clarity of a latent fingerprint. (author)

  16. Risk Communication Concerning Welding Fumes for the Primary Preventive Care of Welding Apprentices in Southern Brazil

    Marta Regina Cezar-Vaz

    2015-01-01

    Full Text Available This study’s aim was to assess the perceptions of welding apprentices concerning welding fumes being associated with respiratory and cardiovascular disorders and assess the implementation of risk communication as a primary prevention tool in the welding training process. This quasi-experimental, non-randomized study with before-and-after design was conducted with 84 welding apprentices in Southern Brazil. Poisson Regression analysis was used. Relative Risk was the measure used with a 95% confidence interval and 5% (p ≤ 0.05 significance level. Significant association was found between perceptions of worsened symptoms of respiratory disorders caused by welding fumes and educational level (p = 0.049, the use of goggles to protect against ultraviolet rays (p = 0.023, and access to services in private health facilities without insurance coverage (p = 0.001. Apprentices younger than 25 years old were 4.9 times more likely to perceive worsened cardiovascular symptoms caused by welding fumes after risk communication (RR = 4.91; CI 95%: 1.09 to 22.2. The conclusion is that risk communication as a primary preventive measure in continuing education processes implemented among apprentices, who are future welders, was efficacious. Thus, this study confirms that risk communication can be implemented as a primary prevention tool in welding apprenticeships.

  17. Development of Welding Fumes Health Index (WFHI for Welding Workplace's Safety and Health Assessment.

    Azian Hariri

    2014-08-01

    Full Text Available This study aimed to develop an index that can rank welding workplace that associate well with possible health risk of welders.Welding Fumes Health Index (WFHI were developed based on data from case studies conducted in Plant 1 and Plant 2. Personal sampling of welding fumes to assess the concentration of metal constituents along with series of lung function tests was conducted. Fifteen metal constituents were investigated in each case study. Index values were derived from aggregation analysis of metal constituent concentration while significant lung functions were recognized through statistical analysis in each plant.The results showed none of the metal constituent concentration was exceeding the permissible exposure limit (PEL for all plants. However, statistical analysis showed significant mean differences of lung functions between welders and non-welders. The index was then applied to one of the welding industry (Plant 3 for verification purpose. The developed index showed its promising ability to rank welding workplace, according to the multiple constituent concentrations of welding fumes that associates well with lung functions of the investigated welders.There was possibility that some of the metal constituents were below the detection limit leading to '0' value of sub index, thus the multiplicative form of aggregation model was not suitable for analysis. On the other hand, maximum or minimum operator forms suffer from compensation issues and were not considered in this study.

  18. New technology developed for optimization of electric arc furnace fume systems

    Anon.

    1997-06-01

    A new control technology for the optimization of electric arc furnace fume systems has been developed by Goodfellow Technologies Inc. The process, entitled the Expert Furnace System Optimization Process (EFSOP{sup TM)}, uses continuous fume analysis, flow measurement and temperature measurement, as well as real-time process data, to adjust fume system setpoints and operation on a minute-by-minute basis. The system can also be used to control post-combustion systems. EFSOP{sup TM} optimizes furnace combustion and reduces energy costs. The furnace off-gas is analyzed just before the combustion gap in order to quantify the availability of carbon monoxide (CO) in the off-gas as a result of incomplete combustion of oxygen and fuel in the furnace shell. Some furnace practices also result in high levels of hydrogen (H{sub 2}) in the off-gas stream. With EFSOP{sup TM}, CO and H{sub 2} concentrations are decreased at every point in the ventilation system thereby minimizing explosion risks in the system.

  19. Fracture Properties of Polypropylene Fiber Reinforced Concrete Containing Fly Ash and Silica Fume

    Qingfu Li

    2013-01-01

    Full Text Available A parametric experimental study has been conducted to investigate the effect of polypropylene fiber on the fracture properties of concrete containing fly ash and silica fume, with five fiber volume fraction (0.04, 0.06, 0.08, 0.1 and 0.12% used. The results indicate that the addition of polypropylene fiber has greatly improved the fracture parameters of concrete composite containing 15% fly ash and 6% silica fume, such as fracture toughness, fracture energy, effective crack length, maximum mid-span deflection, the critical crack opening displacement and the maximum crack opening displacement of the three-point bending beam specimens. When the fiber volume fraction increases from 0 to 0.12%, the fracture parameters increase gradually with the increase of fiber volume fraction. The variation rules of the fracture parameters indicate that the capability of polypropylene fiber to resist crack propagation of concrete composite containing 15% fly ash and 6% silica fume is becoming stronger and stronger with the increase of fiber volume fraction with the fiber volume fraction not beyond 0.12%.

  20. Factors Affecting the Capture Efficiency of a Fume Extraction Torch for Gas Metal Arc Welding.

    Bonthoux, Francis

    2016-07-01

    Welding fumes are classified as Group 2B 'possibly carcinogenic' and this prompts to the implementation of local exhaust ventilation (LEV). The fume extraction torch with LEV integrated into the tool is the most attractive solution but its capture efficiency is often disappointing in practice. This study assesses the main parameters affecting fume capture efficiency namely the extraction flow rate, the positioning of the suction openings on the torch, the angle of inclination of the torch to the workpiece during welding, the metal transfer modes, and the welding deposition rate. The theoretical velocity induced by suction, estimated from the extraction flow rate and the position of the suction openings, is the main parameter affecting effectiveness of the device. This is the design parameter and its value should never be Welding with high deposition rates (>1.1g s(-1)) and spray transfer leads to low capture efficiency if induced velocities are <0.5 m s(-1) The results of the study can be used in the design of integrated on-torch extraction systems and provide information for fixing system objectives. PMID:27074798

  1. Potentiometric titration of excess cadmium in cadmium selenide

    A simple and rapid potentiometric technique for determining excess cadmium in CdSe has been developed. Reaction with AgNO3 is used for sample treatment. Silver, formed in the AgNO3 reaction with excess Cd is determined with the help of KI. When using the given method of analysis the relative standard deviation is equal to 0.08-0.21. The real detection limit of excess cadmium is 9x10-7 g

  2. Cadmium(2) complexes of cytosine

    Complexes of cadmium(2) with cytosine obtained from aqueous or physiological solutions at room temperature are reported. The complexes were characterized by spectroscopic, conductometric, 1H-NMR, and 13C-NMR measurements and also by thermogravimetry. (Authors)

  3. Discovery of the Cadmium Isotopes

    Amos, S.; Thoennessen, M

    2009-01-01

    Thirty-seven cadmium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  4. Cadmium telluride nuclear radiation detectors

    The characteristics and performance of undoped high resistivity cadmium telluride detectors are compared to chlorine lifted counters. It is shown, in particular, that Undodep CdTe is in fact aluminium doped and that compensation occurs, as an silicon or germanium, by pair and triplet formation between the group III donor and the doubly charged cadmium vacancy acceptor. Furthermore, in chlorine doped samples, the polarization effect results from the unpaired level at Esub(c)-0,6eV

  5. Speciation of Dissolved Cadmium

    Holm, Peter Engelund; Andersen, Sjur; Christensen, Thomas Højlund

    1995-01-01

    Equilibrium dialysis and ion exchange methods, as well as computer calculations (GEOCHEM), were applied for speciation of dissolved cadmium (Cd) in test solutions and leachate samples. The leachate samples originated from soil, compost, landfill waste and industrial waste. The ion exchange (IE......) method separates dissolved Cd into free divalent Cd (Cd 2+) and complexed Cd and furthermore separates the latter into the operationally defined forms: labile, slowly labile and stable complexes. The dialysis (ED) method determines high molecular weight Cd complexes (above 1000mol. wt). For both methods...... the reproducibility was good. By combining the results of the GEOCHEM calculations in terms of the inorganic complexes, and the IE results, the fractions of free and inorganically complexed Cd were estimated. The IE and ED results furthermore provided information about the organic complexes. Selected...

  6. Cadmium accumulation and depuration in Anodonta anatina exposed to cadmium chloride or cadmium-EDTA complex

    Holwerda, D.A.; Hemelraad, J.; Veenhof, P.R.; Zandee, D.I.

    1988-03-01

    The authors have previously reported on the uptake and distribution of cadmium in unionids, experimentally exposed to cadmium chloride. The purpose of the present investigation was to study the effect of metal chelation on cadmium kinetics, including metal elimination in the post-exposure phase. Generally, chelation of ionic metal by natural substances like humic acids or by synthetic compounds like EDTA decreases its environmental toxicity through a diminished rate of uptake, as compared with the free ion. The influences of metal chelation on bioconcentration and on toxicity do not always run parallel. To their knowledge, there are no data on the effect of chelation on metal kinetics in freshwater clams. Data on rates of cadmium elimination from aquatic invertebrates are highly divergent, but Cd excretion is invariably found to be smaller than uptake.

  7. Deletion of Phytochelatin Synthase Modulates the Metal Accumulation Pattern of Cadmium Exposed C. elegans

    Yona J. Essig

    2016-02-01

    Full Text Available Environmental metal pollution is a growing health risk to flora and fauna. It is therefore important to fully elucidate metal detoxification pathways. Phytochelatin synthase (PCS, an enzyme involved in the biosynthesis of phytochelatins (PCs, plays an important role in cadmium detoxification. The PCS and PCs are however not restricted to plants, but are also present in some lower metazoans. The model nematode Caenorhabditis elegans, for example, contains a fully functional phytochelatin synthase and phytochelatin pathway. By means of a transgenic nematode strain expressing a pcs-1 promoter-tagged GFP (pcs-1::GFP and a pcs-1 specific qPCR assay, further evidence is presented that the expression of the C. elegans phytochelatin synthase gene (pcs-1 is transcriptionally non-responsive to a chronic (48 h insult of high levels of zinc (500 μM or acute (3 h exposures to high levels of cadmium (300 μM. However, the accumulation of cadmium, but not zinc, is dependent on the pcs-1 status of the nematode. Synchrotron based X-ray fluorescence imaging uncovered that the cadmium body burden increased significantly in the pcs-1(tm1748 knockout allele. Taken together, this suggests that whilst the transcription of pcs-1 may not be mediated by an exposure zinc or cadmium, it is nevertheless an integral part of the cadmium detoxification pathway in C. elegans.

  8. Zinc-induced protection against cadmium

    Early, J.L.; Schnell, R.C.

    1978-02-01

    Pretreatment of male rats with cadmium acetate potentiates the duration of hexobarbital hypnosis and inhibits the rate of hepatic microsomal drug metabolism. Pretreatment of rats with zinc acetate protects against these alterations in drug action elicited by cadmium.

  9. Effect of silica fume on the fresh and hardened properties of fly ash-based self-compacting geopolymer concrete

    Memon, Fareed Ahmed; Nuruddin, Muhd Fadhil; Shafiq, Nasir

    2013-02-01

    The effect of silica fume on the fresh and hardened properties of fly ash-based self-compacting geopolymer concrete (SCGC) was investigated in this paper. The work focused on the concrete mixes with a fixed water-to-geopolymer solid (W/Gs) ratio of 0.33 by mass and a constant total binder content of 400 kg/m3. The mass fractions of silica fume that replaced fly ash in this research were 0wt%, 5wt%, 10wt%, and 15wt%. The workability-related fresh properties of SCGC were assessed through slump flow, V-funnel, and L-box test methods. Hardened concrete tests were limited to compressive, splitting tensile and flexural strengths, all of which were measured at the age of 1, 7, and 28 d after 48-h oven curing. The results indicate that the addition of silica fume as a partial replacement of fly ash results in the loss of workability; nevertheless, the mechanical properties of hardened SCGC are significantly improved by incorporating silica fume, especially up to 10wt%. Applying this percentage of silica fume results in 4.3% reduction in the slump flow; however, it increases the compressive strength by 6.9%, tensile strength by 12.8% and flexural strength by 11.5%.

  10. Effect of Fly Ash and Silica Fume on Hydration Rate of Cement Pastes and Strength of Mortars

    LIU Jun; ZHANG Yun; LIU Runqing; ZHANG Bing

    2014-01-01

    The effect of fly ash and silica fume on hydration rate and strength of cement in the early stage was studied. Contrast test was applied to the complex cementitious system to investigate the hydration rate. Combined with mechanical strength, the influence of fly ash and silica fume during the hydration process of complex binder was researched. The peak of the rate of hydration heat evolution and the mechanical strength decreased as the ratio of fly ash increased, however, as the ratio of silica fume increased, the peak of the rate of hydration heat evolution and the mechanical strength increased obviously. When the ratios of fly ash and silica fume are 10%and 5%, the peak of the rate of hydration heat evolution is the highest. At the same time 7 days of flexural and compressive strength are the highest as 8.89 MPa and 46.52 MPa, respectively. Fly ash and silica fume are the main factors affecting the hydration rate and the mechanical property.

  11. Multi-generation cadmium acclimation and tolerance in Daphnia magna Straus

    The cladoceran Daphnia magna was acclimated for seven generations to cadmium concentrations ranging from 0 (control) to 250 μg/l Cd (corresponding to a free ion activity of 4.60 nM Cd2+). Acute and chronic cadmium tolerance as well as cadmium accumulation were monitored as a function of acclimation time. After two to three generations of acclimation to concentrations ranging from 0.23 to 1.11 nM Cd2+ increases in acute tolerance were maximal (factor 7.2) and significant. Acclimation for seven generations to the same acclimation concentrations did result in an increased chronic cadmium tolerance (21 days EC50 values increased). Organisms acclimated to 1.93 nM Cd2+ were equally or more sensitive than non-acclimated daphnids in acute and chronic toxicity tests. Cadmium contents in D. magna increased significantly as a function of the acclimation concentration. Maximum body burdens of 236±30 μg Cd/g dry weight were measured in organisms exposed to 4.60 nM Cd2+, but detoxification mechanisms were only successful up to 82±20 μg Cd/g dry weight as this concentration did not cause major decreases in survival and reproduction in chronic toxicity tests. As the potential positive effect of acclimation on cadmium tolerance disappeared with successive acclimation generations and increasing acclimation concentrations, it is concluded that multi-generation acclimation studies are important for the evaluation of the long-term effects of environmental toxicants. - Multi-generation acclimation studies are important for evaluating long-term effects of aquatic pollutants

  12. Welding fumes exposure, body mass index and duration of smoking decrease physical fi tness among welders

    Rudy Wahyu Perdana

    2012-09-01

    Full Text Available AbstrakLatar belakang: Pajanan asap pengelasan dapat mengganggu kesehatan, antara lain penurunan kebugaran jasmani. Penelitian ini bertujuan menganalisis efek pajanan asap pengelasan terhadap kebugaran jasmani pengelas.Metode: Penelitian menggunakan desain potong lintang dan subjek penelitian dipilih secara purposif di antara pengelas di suatu pabrik knalpot di sekitar Jakarta tahun 2012. Beberapa karakteristik demografi , riwayat pekerjaan, dan kebiasaan subjek diperloleh dengan wawancara. Kebugaran jasmani diperiksa dengan metode Queen’s College Step Test. Total pajanan asap dinilai menggunakan metode semi kuantitatif yaitu perkalian pajanan asap dengan masa kerja sebagai pengelas.Hasil: Subjek penelitian berjumlah 110 orang, yang berusia antara 19-55 tahun, dengan masa kerja 1-16 tahun. Pajanan asap diperusahaan sebesar 15 mg/m3 menurut data pemeriksaan rutin perusahaan tahun 2012. Umur dan aktivitas fi sik tidak berkorelasi terhadap tingkat kebugaran jasmani pengelas. Akan tetapi didapatkan korelasi negatif antara total pajanan asap, index massa tubuh (IMT, dan kebiasaan lama merokok terhadap tingkat kebugaran jasmani pengelas. Korelasi terhadap tingkat kebugaran jasmani pengelas tersebut adalah: total pajanan asap [koefi sien regresi (r = -0,07; 95% koefi sien interval (CI = -0,10; -0,04]; IMT (r =-0,38; 95% CI = -0,64;-0,09; dan kebiasaan lama merokok (r = -0,16; 95% CI = -0,28;-0,04Kesimpulan: Peningkatan pajanan asap pengelasan, index massa tubuh, dan lama merokok menurunkan tingkat kebugaran jasmani pengelas. (Health Science Indones 2012;1:37-40Kata kunci: pajanan asap, kebugaran jasmani, Queen’s College Step Test AbstractBackground: Welding fumes exposure caused health disorders, one of them are decreasing the level of physical fi tness. This study aimed to analyze the effect of welding fumes exposure with the level of welder’sphysical fi tness.Methods: This cross-sectional using purposive selected by sampling selection method

  13. Bioavailability of cadmium from linseed and cocoa

    Hansen, Max; Sloth, Jens Jørgen; Rasmussen, Rie Romme

    In Denmark and EU the exposure of cadmium from food is at a level that is relatively close to the Tolerable Daily Intake (TDI). This report describes an investigation of the bioavailability of cadmium in selected food items known to contain high levels of cadmium. The purpose was to provide data ...... crushed linseed nor the intake of cocoa and chocolate....

  14. Cadmium purification and quantification using immunochromatography.

    Sasaki, Kazuhiro; Yongvongsoontorn, Nunnarpas; Tawarada, Kei; Ohnishi, Yoshikazu; Arakane, Tamami; Kayama, Fujio; Abe, Kaoru; Oguma, Shinichi; Ohmura, Naoya

    2009-06-10

    One of the pathways by which cadmium enters human beings is through the consumption of agricultural products. The monitoring of cadmium has a significant role in the management of cadmium intake. Cadmium purification and quantification using immunochromatography were conducted in this study as an alternative means of cadmium analysis. The samples used in this study were rice, tomato, lettuce, garden pea, Arabidopsis thaliana (a widely used model organism for studying plants), soil, and fertilizer. The cadmium immunochromatography has been produced from the monoclonal antibody Nx2C3, which recognize the chelate form of cadmium, Cd.EDTA. The immunochromatography can be used for quantification of cadmium in a range from 0.01 to 0.1 mg/L at 20% mean coefficient of variance. A chelate column employing quaternary ammonium salts was used for the purification of cadmium from HCl extracts of samples. Recoveries of cadmium were near 100%, and the lowest recovery was 76.6% from rice leaves. The estimated cadmium concentrations from the immunochromatography procedure were evaluated by comparison with the results of instrumental analysis (ICP-AES or ICP-MS). By comparison of HCl extracts analyzed by ICP-MS and column eluates analyzed by immunochromatography of the samples, the estimated cadmium concentrations were closely similar, and their recoveries were from 98 to 116%. PMID:19489614

  15. Smog chamber study on the evolution of fume from residential coal combustion

    Chunmei Geng; Kun Wang; Wei Wang; Jianhua Chen; Xiaoyu Liu; Hongjie Liu

    2012-01-01

    Domestic coal stoves are widely used in countryside and greenbelt residents in China for heating and cooking,and emit considerable pollutants to the atmosphere because of no treatment of their exhaust,which can result in deteriorating local air quality.In this study,a dynamic smog chamber was used to investigate the real-time emissions of gaseous and particulate pollutants during the combustion process and a static smog chamber was used to investigate the fume evolution under simulate light irradiation.The real-time emissions revealed that the total hydrocarbon (THC) and CO increased sharply after ignition,and then quickly decreased indicating volatilization of hydrocarbons with low molecular weight and incomplete combustion at the beginning stage of combustion made great contribution to these pollutants.There was evident shoulder peak around 10 min combustion for both THC and CO,revealing the emissions from vitrinite combustion.Additionally,another broad emission peak of CO after 30 min was also observed,which was ascribed to the incomplete combustion of the inertinite.Compared with THC and CO,there was only one emission peak for NOx,SO2 and particular matters at the beginning stage of combustion.The fume evolution with static chamber simulation indicated that evident consumption of SO2 and NOx as well as new particle formation were observed.The consumption rates for SO2 and NOx were about 3.44% hr-1 and 3.68% hr-1,the new particle formation of nuclei particles grew at a rate of 16.03 nm/hr during the first reaction hour,and the increase of the diameter of accumulation mode particles was evident.The addition of isoprene to the diluted mixture of the fume could promote O3 and secondary particle formation.

  16. Cycling of lithium/metal oxide cells using composite electrolytes containing fumed silicas

    The effect on cycle capacity is reported of cathode material (metal oxide, carbon, and current collector) in lithium/metal oxide cells cycled with fumed silica-based composite electrolytes. Three types of electrolytes are compared: filler-free electrolyte consisting of methyl-terminated poly(ethylene glycol) oligomer (PEGdm, Mw=250)+lithium bis(trifluromethylsufonyl)imide (LiTFSI) (Li:O=1:20), and two composite systems of the above baseline liquid electrolyte containing 10-wt% A200 (hydrophilic fumed silica) or R805 (hydrophobic fumed silica with octyl surface group). The composite electrolytes are solid-like gels. Three cathode active materials (LiCoO2, V6O13, and LixMnO2), four conducting carbons (graphite Timrex [reg] SFG 15, SFG 44, carbon black Vulcan XC72R, and Ketjenblack EC-600JD), and three current collector materials (Al, Ni, and carbon fiber) were studied. Cells with composite electrolytes show higher capacity, reduced capacity fade, and less cell polarization than those with filler-free electrolyte. Among the three active materials studied, V6O13 cathodes deliver the highest capacity and LixMnO2 cathodes render the best capacity retention. Discharge capacity of Li/LiCoO2 cells is affected greatly by cathode carbon type, and the capacity decreases in the order of Ketjenblack>SFG 15>SFG 44>Vulcan. Current collector material also plays a significant role in cell cycling performance. Lithium/vanadium oxide (V6O13) cells deliver increased capacity using Ni foil and carbon fiber current collectors in comparison to an Al foil current collector

  17. Development and characterization of an inclined air-curtain (IAC) fume hood.

    Huang, Rong Fung; Chen, Jia-Kun; Tang, Kun-Chi

    2015-06-01

    An inclined air-curtain (IAC) fume hood was developed and characterized using the laser-assisted smoke flow visualization technique and tracer-gas (sulphur hexafluoride) concentration detection method. The IAC fume hood features four innovative design elements: (i) an elongated suction slot installed at the hood roof with an offset towards the rear wall, (ii) an elongated up-blowing planar jet issued from the work surface near the hood inlet, (iii) two deflection plates installed at the left and right side walls, and (iv) a boundary-layer separation controller installed at the sash bottom. Baffles employed in conventional hoods were not used. The suction slot and the up-blowing planar jet formed a rearward-inclined push-pull air curtain. The deflection plates worked with the inclined air curtain to induce four rearward-inclined counter-rotating 'tornados.' The fumes generated in the hood were isolated behind the rearward-inclined air curtain, entrained by the low pressure within the vortical flows, moved up spirally, and finally exhausted through the suction slot. The risk of containment leakage due to the large recirculation vortex that usually exists behind the sash of conventional hoods was reduced by the boundary-layer separation controller. The results of the tracer-gas concentration detection method based on the EN-14175 method showed that the flow field created by the geometric configurations of the IAC hood presented characteristics of low leakage and high resistance to dynamic disturbances at low face velocities. The leakage levels measured by the static, sash movement, and walk-by tests were negligible at a face velocity of 0.26 m s(-1). PMID:25690760

  18. Mechanisms of cadmium carcinogenesis

    Cadmium (Cd), a heavy metal of considerable occupational and environmental concern, has been classified as a human carcinogen by the International Agency for Research on Cancer (IARC). The carcinogenic potential of Cd as well as the mechanisms underlying carcinogenesis following exposure to Cd has been studied using in vitro cell culture and in vivo animal models. Exposure of cells to Cd results in their transformation. Administration of Cd in animals results in tumors of multiple organs/tissues. Also, a causal relationship has been noticed between exposure to Cd and the incidence of lung cancer in human. It has been demonstrated that Cd induces cancer by multiple mechanisms and the most important among them are aberrant gene expression, inhibition of DNA damage repair, induction of oxidative stress, and inhibition of apoptosis. The available evidence indicates that, perhaps, oxidative stress plays a central role in Cd carcinogenesis because of its involvement in Cd-induced aberrant gene expression, inhibition of DNA damage repair, and apoptosis.

  19. Cadmium uptake by plants

    Haghiri, F.

    1973-01-01

    Absorption of /sup 115m/Cd by soybean (Gylcine max l.) plants via foliar and root systems and translocation into the seed was determined. The uptake of /sup 115m/Cd by soybeans via the root system was more efficient than that of the foliar placement. Growth and Cd concentrations of soybean and wheat (Triticum aestivum l.) tops were influenced by soil-applied Cd. In both crops, the Cd concentration of plant tops increased while yield decreased with increasing levels of applied Cd. Cadmium toxicitiy began to occur in both crops at the lowest level of soil applied Cd (2.5 ppM). With soybean plants, Cd toxicity symptoms resembled fe chlorosis. For wheat plants there were no visual symptoms other than the studied growth. The relative concentration of Cd found in several vegetable crops varied depending on the plant species. The relative Cd concentration in descending order for various vegetables was lettuce (Lactuca sativa l.) > radish top (Raphanus sativus l.) > celery stalk (Apium graveolens l.) > celery leaves greater than or equal to green pepper (Capsicum frutescens l.) > radish roots.

  20. Toxicity prediction of binary combinations of cadmium, carbendazim and low dissolved oxygen on Daphnia magna

    Environmental contamination is often characterised by a combination of stress factors of various sources (biological, physical and chemical). The predictability of their joint effects is an important stage in environmental risk assessment procedures. In this study, the two main conceptual models for mixture evaluation based on the effect of individual compounds, concentration addition (CA) and independent action (IA) and deviations to synergism/antagonism, 'dose ratio' and 'dose level' dependency were used. The single and combined effects of cadmium, carbendazim and low dissolved oxygen levels were assayed for life-cycle parameters (survival and feeding) of the water flea Daphnia magna Straus. The results of single exposures revealed an increase of acute and chronic toxicity as concentrations of cadmium and carbendazim increases. At low dissolved oxygen levels both survival and feeding parameters were significantly affected (P ≤ 0.05). In the acute mixture exposure of cadmium and carbendazim a 'dose ratio' dependency was observed with a higher toxicity when cadmium was dominant whereas at high concentrations of carbendazim a lower effect on survival was observed. At chronic exposures an antagonistic deviation from IA model was observed for this mixture. The IA model showed to be adequate for toxicity prediction on acute exposure combinations with low DO levels where a synergistic behaviour was observed. However, at sublethal exposures IA and CA models failed by underestimation. Validation from toxicokinetic and toxicodynamic modelling studies should be made in the future as a way to understand toxicological pathways involved in complex mixture/combination exposures

  1. Influence of cadmium on ketamine-induced anesthesia and brain microsomal Na[sup +], K[sup +]-ATPase in mice

    Shen, Y.; Sangiah, S. (Oklahoma State Univ., Stillwater, OK (United States))

    1994-10-01

    Cadmium is a rare metallic element, present in almost all types of food. Shellfish, wheat and rice accumulate very high amounts. Occupational and environmental pollutants are the main sources of cadmium exposure. Cadmium has a very long biologic half-life. Exposure to Cadmium causes anemia, hypertension, hepatic, renal, pulmonary and cardiovascular disorders as well as being a possible mutagen, teratogen and carcinogen. Acute cadmium treatment increased the hexobarbital sleeping time and inhibited hepatic microsomal drug metabolism due to a decrease in cytochrome P[sub 450] content. Cadmium potentiated ethanol-induced sleep in a dose-dependent manner. Cadmium has been shown to inhibit brain microsomal Na[sup +], K[sup +]-ATPase activity in vitro and in vivo. Cadmium and ethanol additively inhibited brain Na[sup +], K[sup +]-ATPase. This might be a direct interaction between cadmium and ethanol in the central nervous system. Ketamine is an intravenous anesthetic agent. It acts on central nervous system and produces [open quotes]dissociative anaesthesia.[close quotes] Ketamine provides adequate surgical anesthesia and is used alone in humans and/or combination with xylazine, an [alpha][sub 2]-adrenergic agonist in animals. It produces CNS depression, analgesia, amnesia, immobility and a feeling of dissociation from the environment. Ketamine is a non-competitive antagonist of the NMDA subset of the glutamate receptor. This perhaps results in an increase in neuronal activity leading to disorganization of normal neurotransmission and produces dissociative anesthetic state. Because it is different from most other anesthetics, ketamine may be expected to have a unique effect on brain biochemical parameters and enzymes. The purpose of this study was to examine the interactions between cadmium and ketamine on the central nervous system and ATPase, in an attempt to further understand the mechanism of action. 12 refs., 3 figs.

  2. Morphological, rheological and electrochemical studies ofpoly(ethylene oxide) electrolytes containing fumed silicananoparticles

    Xie, Jiangbing; Kerr, John B.; Duan, Robert G.; Han, Yongbong

    2003-06-01

    In this paper, the rheology and crystallization of composite Poly(Ethylene Oxide) (PEO) electrolytes were studied by dynamic mechanical analysis, DSC and polarized light microscopy. The effects of fumed silica nanoparticles on the conductivities of the polymer electrolytes at temperatures above and below their melting point were measured and related to their rheology and crystallization behavior, respectively. The electrolyte/electrode interfacial properties and cycling performances of the composite polymer electrolytes in Li/Li cells are also discussed. The measured electrochemical properties were found to depend heavily on the operational environments and sample processing history.

  3. Hypergolic Burning of Formylidene and Furfurylidene amines with Red Fuming Nitric Acid as Oxidizer

    S. P. Panda

    1977-04-01

    Full Text Available Six p-formylidene and six p-furfurylideneamines were synthesized and their ignition delay with red fuming nitric acid (RFNA were measured by cup test method using a high speed camera. Structure - hypergolicity correlation revealed that a p-methyl group inhibits hypergolicity whereas a p-methoxy group accelerates it. Similarly oxidizable non-conjugated benzene rings increase hypergolicity whereas conjugated benzene rings decrease it. On compacting, the p-formylidene anisidine was found to be hypergolic with an ignition delay less than 100 milliseconds.

  4. Investigation of Fumed Silica/Aqueous NaCl Superdielectric Material

    Natalie Jenkins; Clayton Petty; Jonathan Phillips

    2016-01-01

    A constant current charge/discharge protocol which showed fumed silica filled to the point of incipient wetness with aqueous NaCl solution to have dielectric constants >108 over the full range of dielectric thicknesses of 0.38–3.9 mm and discharge times of 0.25–>100 s was studied, making this material another example of a superdielectric. The dielectric constant was impacted by both frequency and thickness. For time to discharge greater than 10 s the dielectric constant for all thicknes...

  5. Intermolecular Interaction and Vibrational Spectra at Fumed Silica Particles/Silicone Polymer Interface

    A microscopic view on the interface formed by fumed silica particle and silicone polymers is suggested basing on a combined study that involves quantum-chemical (QCh) calculations and vibrational spectroscopic experiment. The former were performed for model clusters simulating a real 'area of contact' on the interface. Vibrational spectra were obtained for commercial products. Calculated vibrational spectra, obtained for model clusters by using force constants determined in due course of the QCh study, provided a quite perfect linkage between the QCh results and experimental spectra. This makes the suggested QCh microscopic description highly reliable

  6. Interstitial pneumonia caused by inhalation of fumes of nickel and chrome.

    Hisatomi, Keiko; Ishii, Hiroshi; Hashiguchi, Koji; Seki, Masafumi; Ide, Mioko; Sugiyama, Kanako; Ishimoto, Hiroshi; Nakayama, Seiko; Mukae, Hiroshi; Kohno, Shigeru

    2006-11-01

    Two male industrial painters were admitted to hospital with dry cough and dyspnoea on exertion following a tank coating operation using a high-temperature spray paint consisting of a nickel-chromium alloy. Both patients showed hypoxaemia, peripheral leukocytosis, high levels of serum cytokines and bilateral ground-glass opacities on a chest CT scan. They were diagnosed with interstitial pneumonia caused by inhalation of nickel and chrome fumes and successfully treated with corticosteroid. These are rare cases of interstitial pneumonia associated with nickel/chromium inhalation. PMID:17052314

  7. Rocket Performance of Red Fuming Nitric Acid with Blends of Norbornadiene, Carene and Cardanol

    R. Chhibber; C. Prabhakaran; Kulkarni, S. G.; S.P. Panda

    1992-01-01

    The fuel blends of nornornadiene and carene (50:50 by weight) and norbornadiene, carene and cardanol (40:40:20 by weight) exhibit synergistic hypergolic ignition with red fuming nitric acid (RFNA) as oxidiser. These fuel blends have been evaluated by theoretical calculations of performance parameters and subsequently verified by static firing in a 10 kg/sub f/ thruster at a chamber pressure of around 20 atm, using RFNA (with 21 per cent N/sub 2/O/sub 4/ by weight) as oxidiser. The theo...

  8. Development of indigenous local exhaust ventilation system: reduction of welders exposure to welding fumes.

    Zaidi, Shakeel; Sathawara, Natvarbhai; Kumar, Sunil; Gandhi, Sumitra; Parmar, Chimanlal; Saiyed, Habibullah

    2004-07-01

    Two (portable and mobile) local exhaust ventilation (LEV) units were developed in collaboration with the Rural Technology Institute, Gandhinagar, India. Basically, each unit consists of three parts comprising an electric motor, a blower and a fume hood. In both units the motor is fixed in a rectangular iron frame in a foot-mount position and equipped compactly with a blower, which in turn is connected to a fume hood through a flexible hosepipe. The portable unit is light in weight (50 kg) and has a cone shaped metallic fume hood. The mobile unit, on the other hand, differs from the portable model with respect to its weight (150 kg), size, RPM, voltage requirement, hood shape and size, and has a motor enclosure. The efficiency of the portable and mobile units on trial bases was tested by measuring the manganese concentration as a reference metal in welding fumes generated by electric arc welding. The concentration of manganese (mean +/- SD) was 0.218 +/- 0.06 microg/m3 in the general environment. In the workplace area where joining of metal objects by welding was done, the concentration of manganese was found to be 0.63 +/- 0.09 and 3.75 +/- 0.56 microg/m3 at a distance of 5 m and 2 m away from the site of operation, respectively. In the breathing zone it was 22.16 +/- 20.90 microg/m3 which was reduced to 8.25 +/- 4.5 microg /m3 after application of a portable LEV showing about 63% removal of the manganese concentration from the breathing zone of the welder. In another experiment conducted with a mobile LEV unit for heavy-duty work, the concentration of manganese in the breathing zone without operating the mobile LEV was 70.06 +/- 37.38 microg /m3 but was lowered to 8.29 +/- 1.76 microg /m3 after operating the mobile LEV. This indicated an average removal of manganese content by about 88% from the breathing zone of the welder. In both the experiments locations of sample collection were similar. PMID:15308834

  9. Refreshing the Aged Latent Fingerprints with Ionizing Radiation Prior to the Cyanoacrylate Fuming Procedure: A Preliminary Study.

    Ristova, Mimoza M; Radiceska, Pavlina; Bozinov, Igorco; Barandovski, Lambe

    2016-05-01

    One of the crucial factors determining the cyanoacrylate deposit quality over latent fingerprints appeared to be the extent of the humidity. This work focuses on the enhancement/refreshment of age-degraded latent fingerprints by irradiating the samples with UV, X-ray, or thermal neutrons prior to the cyanoacrylate (CA) fuming. Age degradation of latent fingerprints deposited on glass surfaces was examined through the decrease in the number of characteristic minutiae counts over time. A term "critical day" was introduced for the time at which the average number of identifiable minutiae definitions drops to one-half. Fingerprints older than their "critical day" were exposed to either UV, X-ray, or thermal neutrons. Identical reference samples were kept unexposed. All samples, both reference and irradiated, were developed during a single CA fuming procedure. Comparative latent fingerprint analysis showed that exposure to ionizing radiation enhances the CA fuming, yielding a 20-30% increase in average minutiae count. PMID:27122421

  10. 42 CFR 84.1144 - Silica dust test for dust, fume, and mist respirators; single-use or reusable filters; minimum...

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Silica dust test for dust, fume, and mist... Silica dust test for dust, fume, and mist respirators; single-use or reusable filters; minimum... the chamber will not be less than 50 nor more than 60 milligrams of flint (99+ percent free...

  11. Effectiveness of amorphous silica encapsulation technology on welding fume particles and its impact on mechanical properties of welds

    Highlights: • A novel welding shielding gas containing a silica precursor. • Up to 76% of the welding fume particles encapsulated in an amorphous silica layer. • No statistical difference between different types of welds in mechanical tests. • Can potentially reduce the toxicity of welding fume particles. - Abstract: Stainless steel welding generates nano-sized fume particles containing toxic metals which may cause serious health effects upon inhalation. The objective of this study was to investigate the effectiveness of an amorphous silica encapsulation (ASE) technology by evaluating its silica coating efficiency (SCE), particle morphology, and its impact on the weld’s mechanical properties. Tetramethylsilane (TMS) added to the welding shielding gas decomposed at the high-temperature arc zone to enable the silica coating. Collected welding fume particles were digested by two acid mixtures with different degrees of silica solubility, and the measured mass differences in the digests were used to determine the SCE. The SCEs were around 48–64% at the low and medium primary shielding gas flow rates. The highest SCE of 76% occurred at the high shielding gas flow rate (30 Lpm) with a TMS carrier gas flow of 0.64 Lpm. Transmission electron microscopy (TEM) images confirmed the amorphous silica layer on the welding fume particles at most gas flow rates, as well as abundant stand-alone silica particles formed at the high gas flow rate. Metallography showed that welds from the baseline and from the ASE technology were similar except for a tiny crack found in one particular weld made with the ASE technology. Tensile tests showed no statistical difference between the baseline and the ASE welds. All the above test results confirm that welding equipment retrofitted with the ASE technology has the potential to effectively address the toxicity problem of welding fume particles without affecting the mechanical properties of the welds

  12. Triglycerides, total cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol in rats exposed to premium motor spirit fumes

    Ogbevire L Aberare

    2011-01-01

    Full Text Available Background: Deliberate and regular exposure to premium motor spirit fumes is common and could be a risk factor for liver disease in those who are occupationally exposed. A possible association between premium motor spirit fumes and plasma levels of triglyceride, total cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol using a rodent model could provide new insights in the pathology of diseases where cellular dysfunction is an established risk factor. Aim: The aim of this study was to evaluate the possible effect of premium motor spirit fumes on lipids and lipoproteins in workers occupationally exposed to premium motor spirit fumes using rodent model. Materials and Methods: Twenty-five Wister albino rats (of both sexes were used for this study between the 4 th of August and 7 th of September, 2010. The rats were divided into five groups of five rats each. Group 1 rats were not exposed to premium motor spirit fumes (control group, group 2 rats were exposed for 1 hour daily, group 3 for 3 hours daily, group 4 for 5 hours daily and group 5 for 7 hours daily. The experiment lasted for a period of 4 weeks. Blood samples obtained from all the groups after 4 weeks of exposure were used for the estimation of plasma levels of triglyceride, total cholesterol, high density lipoprotein- cholesterol and low density lipoprotein- cholesterol. Result: Results showed significant increase in means of plasma total cholesterol and low density lipoprotein levels (P<0.05. The mean triglyceride and total body weight were significantly lower (P<0.05 in the exposed group when compared with the unexposed. The plasma level of high density lipoprotein, the ratio of low density lipoprotein to high density lipoprotein and the ratio of total cholesterol to high density lipoprotein did not differ significantly in exposed subjects when compared with the control group. Conclusion: These results showed that frequent exposure to petrol fumes

  13. Nickel cadmium battery expert system

    1986-01-01

    The applicability of artificial intelligence methodologies for the automation of energy storage management, in this case, nickel cadmium batteries, is demonstrated. With the Hubble Space Telescope Electrical Power System (HST/EPS) testbed as the application domain, an expert system was developed which incorporates the physical characterization of the EPS, in particular, the nickel cadmium batteries, as well as the human's operational knowledge. The expert system returns not only fault diagnostics but also status and advice along with justifications and explanations in the form of decision support.

  14. Abrasion Properties of Steel Fiber Reinforced Silica Fume Concrete According to Los Angeles and Water Abrasion Tests

    Tsan-Ching CHENG; Cheng, An; Huang, Ran; Lin, Wei-Ting

    2014-01-01

    The current study mainly investigated the influence of different tests on the abrasion resistance of concrete mixed with steel fibers and silica fume. The abrasion resistance was assessed at 28, 56 and 91 days on concretes with water-binder ratios of 0.35 and 0.55 where in some mixes silica fume was substituted by 5 % of cement by weight. Steel fibers of 0.5 % and 1.0 % of concrete volume were also added into the test concrete by replacement of coarse and fine aggregates. The results showed t...

  15. The Effect of Exhaust Fumes on Glutathione S-Transferase Enzymes in the Lung of Rats Supplemented with Natural Products

    Muhammad Y. Gwarzo; Fredrick O. Ujah

    2013-01-01

    This study examined the effect of exhaust fumes on the lungs and the impact of dietary supplementation with natural products containing cancer chemopreventive agents in attenuating their effect. Thirty-two rats were grouped into eight groups of four rats each. Groups 1-3 were on non-supplemented diet and exposed to exhaust fumes from generator for time intervals of 5 mins, 1 h and 2 h, respectively at a distance of 2.5 m away from the generator. Groups 4-6 were fed on supplemented diet and ex...

  16. Thyrotoxicity of the Chlorides of Cadmium and Mercury in Rabbit

    NINAGHOSH; SHELLEYBHATTACHARYA

    1992-01-01

    Exposure to heavy metals such as cadmium and mercury is of immediate environmental concern.The present study was aimed at establishing a direct relationship between heavy metal poisoning and thyroid dysfunction.Cadmium and mercury treatment at LD50 levels resulted in severe thyrotoxicosis in the rabbit.Within 24h of intramuscular administration of cadmium chloride 15 mg·kg-1 body weight(bw)and mercury chloride20mg·kg-1 bw,thyroid peroxidase activity increased significantly over the control with a concomitant rise in the triiodothyronie(T3)titre.On the other hand,there was a remarkable fall in the thyroxine(T4)level,and the T3,T4 ratio was high as compared with the control.Evidence indicates that acute heavy metal lethality will induce immediate hyperthyroidism.It is suggested that T3-toxicosis may be produced by a preferential synthesis of T3 and/or preferential deiodination of T4 to T3.Measurement of T3 and T4 levels may thus e utilized as a reliable indicator of heavy metal lethality.

  17. Insulin Expression in Rats Exposed to Cadmium

    2007-01-01

    Objectives To investigate the effects of cadmium exposure on insulin expression in rats. Methods Eighteen adult SD assessed. The levels of cadmium and zinc in pancreas, blood and urine glucose, serum insulin and urine NAG (N-acyetyl-β-glucosaminidase) were determined. The gene expressions of metallothionein (MT) and insulin were also measured,and the oral glucose tolerance tests (OGTT) were carried out. Results The contents of cadmium in pancreas in cadmium-treated rats were higher than that in the control group, which was associated with slight increase of zinc in pancreas.not change significantly after cadmium administration, and the UNAG had no change in Cd-treated group. The gene expression the change of the expression of insulin, MT-Ⅰ and MT-Ⅱ genes. Cadmium can influence the biosynthesis of insulin, but does not induce the release of insulin. The dysfunction of pancreas occurs earlier than that of kidney after administration of cadmium.

  18. Toxicity of cadmium and lead on tropical midge larvae, Chironomus kiiensis Tokunaga and Chironomus javanus Kieffer (Diptera:Chironomidae)

    Warrin Ebau; Che Salmah Md Rawi; Zubir Din; Salman Abdo Al-Shami

    2012-01-01

    Objective: To investigate the acute toxicity of cadmium and lead on larvae of two tropical Chironomid species, Chironomus kiiensis (C. kiiensis) Tokunaga and Chironomus javanus (C. javanus) Kieffer. Methods: Different larval instars (first-fourth) were exposed using a static non-replacement testing procedures to various concentrations of cadmium and lead. Results:In general, younger larvae (first and second instars) of both species were more sensitive to both metals than older larvae (third and forth instars). The toxic effects of the metals on C. kiiensis and C. javanus were influenced by the age of the larvae (first to fourth instars), types of metals (cadmium or lead) and duration of larval exposure (24, 48, 72 and 96 h) to the metals. Conclusions: Cadmium was more toxic to the chironomids than lead and C. javanus was significantly more sensitive to both metals than C. kiiensis (P<0.05).

  19. Cement with silica fume and granulated blast-furnace slag: strength behavior and hydration

    Bonavetti, V. L.

    2014-09-01

    Full Text Available This paper analyses the influence of portland cement replacement by silica fume (up to 10% and/or granulated blast furnace slag (up to 70% on the hydration cement (XRD, heat of hydration, non evaporable water content and calcium hydroxide content curing under sealed conditions and their effect on the mechanical strength. The obtained results indicate that binary cements containing silica fume and ternary cements there was a significant increase of hydration rate at early age. At later ages, most of studied cements have an equivalent or greater strength that those obtained in the plain portland cement.En este trabajo se analiza la influencia de la incorporación al cemento portland de humo de sílice (hasta 10% y/o escoria granulada de alto horno (hasta 70% sobre la hidratación (DRX, calor de hidratación, contenido de agua no evaporable y de hidróxido de calcio, bajo condiciones de curado sellado y su incidencia sobre la resistencia mecánica. Los resultados obtenidos indican que en los cementos binarios con humo de sílice y en los cementos ternarios se produce un importante aumento de la velocidad de hidratación en las primeras edades, mientras que a edades más avanzadas la mayor parte del dominio estudiado alcanza o supera la resistencia obtenida por el cemento portland sin adición.

  20. Lipase immobilization for catalytic applications obtained using fumed silica deposited with MAPLE technique

    Bloisi, Francesco; Califano, Valeria; Perretta, Giuseppe; Nasti, Libera; Aronne, Antonio; Di Girolamo, Rocco; Auriemma, Finizia; De Rosa, Claudio; Vicari, Luciano R. M.

    2016-06-01

    Lipases are enzymes used for catalyzing reactions of acylglycerides in biodiesel production from lipids, where enzyme immobilization on a substrate is required. Silica nanoparticles in different morphologies and configurations are currently used in conjunction with biological molecules for drug delivery and catalysis applications, but up to date their use for triglycerides has been limited by the large size of long-chain lipid molecules. Matrix assisted pulsed laser evaporation (MAPLE), a laser deposition technique using a frozen solution/suspension as a target, is widely used for deposition of biomaterials and other delicate molecules. We have carried out a MAPLE deposition starting from a frozen mixture containing fumed silica and lipase in water. Deposition parameters were chosen in order to increase surface roughness and to promote the formation of complex structures. Both the target (a frozen thickened mixture of nanoparticles/catalyst in water) and the deposition configuration (a small target to substrate distance) are unusual and have been adopted in order to increase surface contact of catalyst and to facilitate access to long-chain molecules. The resulting innovative film morphology (fumed silica/lipase cluster level aggregation) and the lipase functionality (for catalytic biodiesel production) have been studied by FESEM, FTIR and transesterification tests.

  1. Dry plant extracts loaded on fumed silica for direct compression: preparation and preformulation.

    Palma, S D; Manzo, R H; Allemandi, D A

    1999-01-01

    This paper describes the development of a method to load fumed silica with vegetal material (solid residue) from a liquid extract to obtain a solid loaded silica product (LSP) with satisfactory flow properties and compressibility to be processed by direct-compression technology. Extracts of Melissa officinalis L. (M.o.), Cardus marianus L. (C.m.), and Peumus boldus L. (P.b.) were used to load silica support. The release of boldine from LSP (P.b.) reached 100% in HCl 0.1 N solution and only approximately 70% in water. Some physical-mechanical properties of LSP (M.o. and C.m.) alone and LSP-excipient mixtures were determined. The densities (bulk and tap) of LSP were higher than those of fumed silica alone. Consequently, good flow properties of LSP products were observed. On the other hand, flowability, densities, and compactibility of directly compressible excipients (lactose, dicalcium phosphate dihydrate, and microcrystalline cellulose) were not adversely affected when mixed with LSP. PMID:10578506

  2. Significance of face velocity fluctuation in relation to laboratory fume hood performance.

    Tseng, Li-Ching; Huang, Rong Fung; Chen, Chih-Chieh

    2010-01-01

    In order to recognize the problems associated with the transport mechanism of containment during the ventilation process of a laboratory fume hood, a transparent, full scale chemical fume hood is constructed for experimental studies. Distributions of mean velocity and velocity fluctuation in the sash plane are measured using a thermal anemometer. Flow patterns and tracer-gas concentration leakages are respectively diagnosed via the laser-assisted flow visualization method and the EN 14175-3 test protocol. The magnitudes of measured velocity fluctuations exhibit a sharp peak along the perimeter of the sash opening. The results of flow visualization verify that the elevated turbulence fluctuations are induced by the boundary-layer separation when the flow passes over the edges of sash perimeter. The tracer gas experiment shows that the regions where high degree containment leakages detected are located along the perimeter of hood aperture. Eleven commercial hoods which are claimed with fine aerodynamic design are further tested for confirmation of these observations. The results show similar correlations. Conclusions thus are made that large-scale vortex structures occurring around the perimeters of hood aperture due to the boundary-layer separation could induce strong turbulence, and therefore enhance dispersion of the hood containment. PMID:20160407

  3. Hydration of a silica fume blended low-alkali shotcrete cement

    Lothenbach, Barbara; Rentsch, Daniel; Wieland, Erich

    Ettringite and C-S-H are the main hydrates formed during the hydration of the low-alkali cement “ESDRED” consisting of 60% CEM I, 40% microsilica and 4.8% set accelerator. Small quantities of portlandite and hemicarbonate present as intermediate phases destabilise within a few weeks. The use of a set accelerator leads to massive ettringite precipitation, a moderate decalcification of C-S-H and reduction of pH due to presence of dissolved formate. The slow reaction of the silica fume during hydration decalcifies the C-S-H and decreases the alkali concentration to 30 mM and the pH value of the pore solution to 11.5 after 1 year and longer. The further reaction of the silica fume is expected to be slow and to result in a decrease of pH to 11. Further, the destabilisation of ettringite to thaumasite is expected. The long-term stability of C-S-H and the pH of approximately 11 make ESDRED a good candidate for usage in contact with the clay-based barriers of a repository for radioactive waste.

  4. Exposure of Petrol Station Attendants and Auto Mechanics to Premium Motor Sprit Fumes in Calabar, Nigeria

    N. E. Udonwa

    2009-01-01

    Full Text Available A population-based-cross-sectional survey was carried out to investigate the potential risk of exposure to premium motor spirit (PMS fumes in Calabar, Nigeria, among Automobile Mechanics (AM, Petrol Station Attendants (PSA and the general population. Structured questionnaire was administered on the randomly chosen subjects to elicit information on their exposure to PMS. Duration of exposure was taken as the length of work in their various occupations. Venous blood was taken for methaemoglobin (MetHb and packed cells volume (PCV. Mean MetHb value was higher in AM (7.3% and PSA (5.8% than in the subjects from the general population (2.7%. PCV was lower in PSA (30.8%, than AM (33.3% and the subjects from the general population (40.8%. MetHb level was directly proportional, and PCV inversely related, to the duration of exposure. The study suggested increased exposure to petrol fumes among AM, PSA, and MetHb as a useful biomarker in determining the level of exposure to benzene in petrol vapour.

  5. Exposure of Petrol Station Attendants and Auto Mechanics to Premium Motor Sprit Fumes in Calabar, Nigeria

    A population-based-cross-sectional survey was carried out to investigate the potential risk of exposure to premium motor spirit (PMS) fumes in Calabar, Nigeria, among Automobile Mechanics (AM), Petrol Station Attendants (PSA) and the general population. Structured questionnaire was administered on the randomly chosen subjects to elicit information on their exposure to PMS. Duration of exposure was taken as the length of work in their various occupations. Venous blood was taken for methaemoglobin (Met Hb) and packed cells volume (PCV). Mean Met Hb value was higher in AM (7.3%) and PSA (5.8%) than in the subjects from the general population (2.7%). PCV was lower in PSA (30.8%), than AM (33.3%) and the subjects from the general population (40.8%). Met Hb level was directly proportional, and PCV inversely related, to the duration of exposure. The study suggested increased exposure to petrol fumes among AM, PSA, and Met Hb as a useful bio marker in determining the level of exposure to benzene in petrol vapour.

  6. Exposure of Petrol Station Attendants and Auto Mechanics to Premium Motor Sprit Fumes in Calabar, Nigeria

    Udonwa, N. E.; Uko, E. K.; Ikpeme, B. M.; Ibanga, I. A.; Okon, B. O.

    2009-01-01

    A population-based-cross-sectional survey was carried out to investigate the potential risk of exposure to premium motor spirit (PMS) fumes in Calabar, Nigeria, among Automobile Mechanics (AM), Petrol Station Attendants (PSA) and the general population. Structured questionnaire was administered on the randomly chosen subjects to elicit information on their exposure to PMS. Duration of exposure was taken as the length of work in their various occupations. Venous blood was taken for methaemoglobin (MetHb) and packed cells volume (PCV). Mean MetHb value was higher in AM (7.3%) and PSA (5.8%) than in the subjects from the general population (2.7%). PCV was lower in PSA (30.8%), than AM (33.3%) and the subjects from the general population (40.8%). MetHb level was directly proportional, and PCV inversely related, to the duration of exposure. The study suggested increased exposure to petrol fumes among AM, PSA, and MetHb as a useful biomarker in determining the level of exposure to benzene in petrol vapour. PMID:19936128

  7. Cadmium in jamaican bush teas.

    Hoo Fung, L A; Rattray, V R; Lalor, G C

    2014-01-01

    Samples of Jamaican plants used as bush teas were collected from households in high soil-cadmium (Cd) areas of central Jamaica and analysed by graphite furnace atomic absorption spectrophotometry for total cadmium and for cadmium extractable with a hot water brew as prepared for human consumption to determine their contribution to dietary cadmium exposure. The concentrations ranged from < 0.03 to 6.85 µg/g for total Cd, between 1 and 15% of which was extracted with a hot water brew. One cup (200 ml) of the teas examined was found to contain < 0.04-1.18 µg of Cd and would contribute 0.1-0.3 µg of Cd to a person's dietary intake. This is significantly below the provisional tolerable weekly intake (PTWI) of 7 µg Cd/kg body weight established by the World Health Organization (WHO). While this suggests that bush tea consumption does not contribute significantly to the PTWI, some of the teas examined exceed the WHO recommendation of less than 0.3 mg/kg Cd for medicinal plants. PMID:25303189

  8. Thermal loading as a causal factor in exceeding the 0.1 PPM laboratory fume hood control level.

    Chessin, Saul J; Johnston, James D

    2002-07-01

    Tracer gas testing per ANSI/ASHRAE 110-1995 Method of Testing Performance of Laboratory Fume Hoods was used to investigate the role of thermal loading in exceeding laboratory fume hood control levels. Three types of typical laboratory burners (blast, Meeker, and economy) were used to provide a thermal challenge. Heat outputs of between 0 and 61,610 Btu/hr were based on fuel heat capacity (for liquid propane gas) and fuel gas flow rates. Breathing zone concentrations were measured with a MIRAN 1B2 infrared gas analyzer. Also, for each test, the difference between the room and duct temperatures (delta temperature) was measured. Results indicated a linear relationship between heat loads and tracer gas breathing zone concentrations for both Btu/hr and delta temperature. Control levels of 0.1 ppm were exceeded at less than 12,000 Btu/hr. Also, control levels were exceeded at a lower heat load when the tracer gas generation rate was increased. These results indicate that thermal loads in laboratory fume hoods increase the risk of exceeding laboratory fume hood control levels. Some compensatory measures relative to hood configuration and flow rates are recommended for laboratory operations involving heat sources. PMID:12083172

  9. Quantitative exposure matrix for asphalt fume, total particulate matter, and respirable crystalline silica among roofing and asphalt manufacturing workers.

    Fayerweather, William E; Trumbore, David C; Johnson, Kathleen A; Niebo, Ronald W; Maxim, L Daniel

    2011-09-01

    This paper summarizes available data on worker exposures to asphalt fume (soluble fraction), total particulate matter, and respirable crystalline silica (quartz) [hereinafter RCS] over a 30-year period in Owens Corning's asphalt production and roofing manufacturing plants. For the period 1977 through 2006, the air-monitoring database contains more than 1,400 personal samples for asphalt fume (soluble fraction), 2,400 personal samples for total particulate, and 1,300 personal samples for RCS. Unique process-job categories were identified for the asphalt production and roofing shingle manufacturing plants. Quantitative exposures were tabulated by agent, process-job, and calendar period to form an exposure matrix for use in subsequent epidemiologic studies of the respiratory health of these workers. Analysis of time trends in exposure data shows substantial and statistically significant exposure reductions for asphalt fume (soluble fraction), total particulate matter, and respirable crystalline silica at Owens Corning plants. Cumulative distribution plots for the most recent sampling period (2001-2006) show that 95% of the asphalt fume (soluble fraction) measurements were less than 0.25 mg/m3; 95% of the total particulate measurements were less than 2.2 mg/m3; and 95% of the RCS measurements were less than 0.05 mg/m3. Several recommendations are offered to improve the design of future monitoring efforts. PMID:21879950

  10. Association between cooking oil fume exposure and lung cancer among Chinese nonsmoking women: a meta-analysis.

    Xue, Yingbo; Jiang, Ying; Jin, Shan; Li, Yong

    2016-01-01

    Lung cancer has been the main cause of cancer death around the world. Cigarette smoking has been identified as a risk factor for lung cancer in males. However, the etiological factors in nonsmoking women remain elusive. A meta-analysis was conducted to evaluate the relationship between cooking oil fume exposure and lung cancer among Chinese nonsmoking women. Thirteen articles containing three population-based case-control and ten hospital-based case-control studies were included in this meta-analysis. These studies with a total of 3,596 lung cancer women and 6,082 healthy controls were analyzed by RevMan 5.3. Fixed effects model or random effects model was used to obtain pooled estimates of risk ratio. The risk ratios with a 95% CI were 1.74 (95% CI =1.57-1.94) and 2.11 (95% CI =1.54-2.89), respectively. Cooking oil fume exposure as well as not using a kitchen ventilator when cooking was significantly associated with lung cancer among nonsmoking women (Z=10.07, P<0.00001; Z=4.65, P<0.00001). Cooking oil fume exposure, especially lacking a fume extractor, may increase the risk of lung cancer among Chinese nonsmoking women. PMID:27284248

  11. 42 CFR 84.1151 - DOP filter test; respirators designed as respiratory protection against dusts, fumes, and mists...

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false DOP filter test; respirators designed as... filter test; respirators designed as respiratory protection against dusts, fumes, and mists having an air...) All single air-purifying respirator filter units will be tested in an atmosphere concentration of...

  12. Mechanism of Fume Suppression and Performance on Asphalt of Expanded Graphite for Pavement under High Temperature Condition

    HUANG Gang; HE Zhaoyi; HUANG Yangcheng; ZHOU Chao; YUAN Xiaoya

    2014-01-01

    Fume suppression mechanisms and the effect of expanded graphite on the performance of asphalt were studied by applying infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and comprehensive thermal analysis (TG, DSC). The experimental results confirm that asphalt which is mixed with expandable graphite will expand in the process of hot mix, and the expanded graphite layer will swell by the light component in the asphalt. The light component in the asphalt and PAHs adsorption on expanded graphite surface or part of the plug in the expanded graphite layer between plates made nucleation crystallization growth. And the Van der Waals force and the bonding of the lattice can effectively restrain the asphalt fume release. Meanwhile, the expanding agent with oxidative can spread into the asphalt, leading to asphalt oxygenated and plastic abate, while the ductility decreases. Expanded graphite, SBS modifier and environment- friendly plasticizers are used to composite modified asphalt. According to asphalt fume release experiment, normal test of asphalt performance, Brookfield viscosity test, RTFOT test and asphalt mixture tests (high temperature stability, low temperature stability, water stability), it has been proven that the modified asphalt’s performance is better than that of matrix asphalt and equivalent to that of SBS modified asphalt. Furthermore, it has good fume suppression effect.

  13. Profiling stainless steel welding processes to reduce fume emissions, hexavalent chromium emissions and operating costs in the workplace

    Keane, Michael; Siert, Arlen; Stone, Samuel; Chen, Bean T.

    2016-01-01

    Nine gas metal arc welding (GMAW) processes for stainless steel were assessed for fume generation rates, fume generation rates per g of electrode consumed, and emission rates for hexavalent chromium (Cr6+). Elemental manganese, nickel, chromium, iron emissions per unit length of weld and labor plus consumables costs were similarly measured. Flux-cored arc welding and shielded metal arc (SMAW) processes were also studied. The objective was to identify the best welding processes for reducing workplace exposures, and estimate costs for all processes. Using a conical chamber, fumes were collected, weighed, recovered and analyzed by inductively-coupled atomic emission spectroscopy for metals, and by ion chromatography for Cr6+. GMAW processes used were Surface Tension Transfer™, Regulated Metal Deposition™, Cold Metal Transfer™, short-circuit, axial spray, and pulsed spray modes. Flux-cored welding used gas shielding; SMAW used E308 rods. Costs were estimated as dollars per m length of a ¼ in (6.3 mm) thick horizontal butt weld; equipment costs were estimated as ratios of new equipment costs to a 250 ampere capacity SMAW welding machine. Results indicate a broad range of fume emission factors for the processes studied. Fume emission rates per g of electrode were lowest for GMAW processes such as pulsed-spray mode (0.2 mg/g), and highest for SMAW (8 mg fume/g electrode). Emission rates of Cr6+ ranged from 50 to 7800 μg/min, and Cr6+ generation rates per g electrode ranged from 1 to 270μg/g. Elemental Cr generation rates spanned 13 to 330μg/g. Manganese emission rates ranged from 50 to 300μg/g. Nickel emission rates ranged from 4 to140 μg/g. Labor and consumables costs ranged from $3.15 (GMAW pulsed spray) to $7.40 (SMAW) per meter of finished weld, and were measured or estimated for all 11 processes tested. Equipment costs for some processes may be as much as 5 times the cost of a typical SMAW welding machine. The results show that all of the GMAW processes

  14. The Effect of Exhaust Fumes on Glutathione S-Transferase Enzymes in the Lung of Rats Supplemented with Natural Products

    Muhammad Y. Gwarzo

    2013-08-01

    Full Text Available This study examined the effect of exhaust fumes on the lungs and the impact of dietary supplementation with natural products containing cancer chemopreventive agents in attenuating their effect. Thirty-two rats were grouped into eight groups of four rats each. Groups 1-3 were on non-supplemented diet and exposed to exhaust fumes from generator for time intervals of 5 mins, 1 h and 2 h, respectively at a distance of 2.5 m away from the generator. Groups 4-6 were fed on supplemented diet and exposed to exhaust fumes for time intervals of 5 min, 1h and 2 h, respectively at a distance of 2.5 m from the generator. Group 7 was positive control not exposed to exhausted fumes and fed on diet supplemented with natural products. Group 8 was positive control not exposed to exhaust fumes and not on supplement diet. Normal cellular architecture was observed in supplement positive control groups compared with non supplement positive control groups indicated that the integrity of tissues were not compromised following food supplementation. However, large deposit of dark spots were seen in lungs of non supplemented groups on 1h and 2 h exposure groups, respectively. The lungs also showed significant decrease in the Glutathione-S-Transferase (GST level on exposure for 5 min, 1hour and 2 h (p&ang0.05 compared with their respective control groups. It was also observed that the level of Malondialdehyde (MDA increased significantly (p&ang0.05 in non supplement groups compared with their control groups. Combination of natural products significantly reversed the effect of exhaust fumes on the level of GST (p<0.05 and MDA level (p&ang0.05 compared with non supplement groups. Supplementation of diet with natural products had no adverse effect on the integrity of the tissues under examination as demonstrated by histochemical analysis. Hence, combination of natural diet may provide a useful preventive measure against tissue injury consequent to exposed to exhaust fumes

  15. Effect of short-term stainless steel welding fume inhalation exposure on lung inflammation, injury, and defense responses in rats

    Many welders have experienced bronchitis, metal fume fever, lung function changes, and an increase in the incidence of lung infection. Questions remain regarding the possible mechanisms associated with the potential pulmonary effects of welding fume exposure. The objective was to assess the early effects of stainless steel (SS) welding fume inhalation on lung injury, inflammation, and defense responses. Male Sprague-Dawley rats were exposed to gas metal arc-SS welding fume at a concentration of 15 or 40 mg/m3 x 3 h/day for 1, 3, or 10 days. The control group was exposed to filtered air. To assess lung defense responses, some animals were intratracheally inoculated with 5 x 104Listeria monocytogenes 1 day after the last exposure. Welding particles were collected during exposure, and elemental composition and particle size were determined. At 1, 4, 6, 11, 14, and 30 days after the final exposure, parameters of lung injury (lactate dehydrogenase and albumin) and inflammation (PMN influx) were measured in the bronchoalveolar lavage fluid. In addition, particle-induced effects on pulmonary clearance of bacteria and macrophage function were assessed. SS particles were composed of Fe, Cr, Mn, and Ni. Particle size distribution analysis indicated the mass median aerodynamic diameter of the generated fume to be 0.255 μm. Parameters of lung injury were significantly elevated at all time points post-exposure compared to controls except for 30 days. Interestingly, no significant difference in lung PMNs was observed between the SS and control groups at 1, 4, and 6 days post-exposure. After 6 days post-exposure, a dramatic increase in lung PMNs was observed in the SS group compared to air controls. Lung bacteria clearance and macrophage function were reduced and immune and inflammatory cytokines were altered in the SS group. In summary, short-term exposure of rats to SS welding fume caused significant lung damage and suppressed lung defense responses to bacterial infection, but

  16. Profiling stainless steel welding processes to reduce fume emissions, hexavalent chromium emissions and operating costs in the workplace.

    Keane, Michael; Siert, Arlen; Stone, Samuel; Chen, Bean T

    2016-01-01

    Nine gas metal arc welding (GMAW) processes for stainless steel were assessed for fume generation rates, fume generation rates per g of electrode consumed, and emission rates for hexavalent chromium (Cr(6+)). Elemental manganese, nickel, chromium, iron emissions per unit length of weld, and labor plus consumables costs were similarly measured. Flux-cored arc welding and shielded metal arc (SMAW) processes were also studied. The objective was to identify the best welding processes for reducing workplace exposures, and estimate costs for all processes. Using a conical chamber, fumes were collected, weighed, recovered, and analyzed by inductively coupled atomic emission spectroscopy for metals, and by ion chromatography for Cr(6+). GMAW processes used were Surface Tension Transfer, Regulated Metal Deposition, Cold Metal Transfer, short-circuit, axial spray, and pulsed spray modes. Flux-cored welding used gas shielding; SMAW used E308 rods. Costs were estimated as dollars per m length of a ¼ in (6.3 mm) thick horizontal butt weld; equipment costs were estimated as ratios of new equipment costs to a 250 ampere capacity SMAW welding machine. Results indicate a broad range of fume emission factors for the processes studied. Fume emission rates per g of electrode were lowest for GMAW processes such as pulsed-spray mode (0.2 mg/g), and highest for SMAW (8 mg fume/g electrode). Emission rates of Cr(6+) ranged from 50-7800 µg/min, and Cr(6+) generation rates per g electrode ranged from 1-270 µg/g. Elemental Cr generation rates spanned 13-330 µg/g. Manganese emission rates ranged from 50-300 µg/g. Nickel emission rates ranged from 4-140 µg/g. Labor and consumables costs ranged from $3.15 (GMAW pulsed spray) to $7.40 (SMAW) per meter of finished weld, and were measured or estimated for all 11 processes tested. Equipment costs for some processes may be as much as five times the cost of a typical SMAW welding machine. The results show that all of the GMAW processes in this

  17. Cadmium-mediated disruption of cortisol biosynthesis involves suppression of corticosteroidogenic genes in rainbow trout.

    Sandhu, Navdeep; Vijayan, Mathilakath M

    2011-05-01

    Cadmium is widely distributed in the aquatic environment and is toxic to fish even at sublethal concentrations. This metal is an endocrine disruptor, and one well established role in teleosts is the suppression of adrenocorticotrophic hormone (ACTH)-stimulated cortisol biosynthesis by the interrenal tissue. However the mechanism(s) leading to this steroid suppression is poorly understood. We tested the hypothesis that cadmium targets genes encoding proteins critical for corticosteroid biosynthesis, including melanocortin 2 receptor (MC2R), steroidogenic acute regulatory protein (StAR) and cytochrome P450 side chain cleavage enzyme (P450scc), in rainbow trout (Oncorhynchus mykiss). To test this, head kidney slices (containing the interrenal tissues) were incubated in vitro with cadmium chloride (0, 10, 100 and 1000nM) for 4h either in the presence or absence of ACTH (0.5IU/mL). In the unstimulated head kidney slices, cadmium exposure did not affect basal cortisol secretion and the mRNA levels of MC2R and P450scc, while StAR gene expression was significantly reduced. Cadmium exposure significantly suppressed ACTH-stimulated cortisol production in a dose-related fashion. This cadmium-mediated suppression in corticosteroidogenesis corresponded with a significant reduction in MC2R, StAR and P450scc mRNA levels in trout head kidney slices. The inhibition of ACTH-stimulated cortisol production and suppression of genes involved in corticosteroidogenesis by cadmium were completely abolished in the presence of 8-Bromo-cAMP (a cAMP analog). Overall, cadmium disrupts the expression of genes critical for corticosteroid biosynthesis in rainbow trout head kidney slices. However, the rescue of cortisol production as well as StAR and P450scc gene expressions by cAMP analog suggests that cadmium impact occurs upstream of cAMP production. We propose that MC2R signaling, the primary step in ACTH-induced cortocosteroidogenesis, is a key target for cadmium-mediated disruption of

  18. Cadmium-mediated disruption of cortisol biosynthesis involves suppression of corticosteroidogenic genes in rainbow trout

    Sandhu, Navdeep [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada); Vijayan, Mathilakath M., E-mail: mvijayan@uwaterloo.ca [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada)

    2011-05-15

    Cadmium is widely distributed in the aquatic environment and is toxic to fish even at sublethal concentrations. This metal is an endocrine disruptor, and one well established role in teleosts is the suppression of adrenocorticotrophic hormone (ACTH)-stimulated cortisol biosynthesis by the interrenal tissue. However the mechanism(s) leading to this steroid suppression is poorly understood. We tested the hypothesis that cadmium targets genes encoding proteins critical for corticosteroid biosynthesis, including melanocortin 2 receptor (MC2R), steroidogenic acute regulatory protein (StAR) and cytochrome P450 side chain cleavage enzyme (P450scc), in rainbow trout (Oncorhynchus mykiss). To test this, head kidney slices (containing the interrenal tissues) were incubated in vitro with cadmium chloride (0, 10, 100 and 1000 nM) for 4 h either in the presence or absence of ACTH (0.5 IU/mL). In the unstimulated head kidney slices, cadmium exposure did not affect basal cortisol secretion and the mRNA levels of MC2R and P450scc, while StAR gene expression was significantly reduced. Cadmium exposure significantly suppressed ACTH-stimulated cortisol production in a dose-related fashion. This cadmium-mediated suppression in corticosteroidogenesis corresponded with a significant reduction in MC2R, StAR and P450scc mRNA levels in trout head kidney slices. The inhibition of ACTH-stimulated cortisol production and suppression of genes involved in corticosteroidogenesis by cadmium were completely abolished in the presence of 8-Bromo-cAMP (a cAMP analog). Overall, cadmium disrupts the expression of genes critical for corticosteroid biosynthesis in rainbow trout head kidney slices. However, the rescue of cortisol production as well as StAR and P450scc gene expressions by cAMP analog suggests that cadmium impact occurs upstream of cAMP production. We propose that MC2R signaling, the primary step in ACTH-induced cortocosteroidogenesis, is a key target for cadmium-mediated disruption of

  19. Cadmium-mediated disruption of cortisol biosynthesis involves suppression of corticosteroidogenic genes in rainbow trout

    Cadmium is widely distributed in the aquatic environment and is toxic to fish even at sublethal concentrations. This metal is an endocrine disruptor, and one well established role in teleosts is the suppression of adrenocorticotrophic hormone (ACTH)-stimulated cortisol biosynthesis by the interrenal tissue. However the mechanism(s) leading to this steroid suppression is poorly understood. We tested the hypothesis that cadmium targets genes encoding proteins critical for corticosteroid biosynthesis, including melanocortin 2 receptor (MC2R), steroidogenic acute regulatory protein (StAR) and cytochrome P450 side chain cleavage enzyme (P450scc), in rainbow trout (Oncorhynchus mykiss). To test this, head kidney slices (containing the interrenal tissues) were incubated in vitro with cadmium chloride (0, 10, 100 and 1000 nM) for 4 h either in the presence or absence of ACTH (0.5 IU/mL). In the unstimulated head kidney slices, cadmium exposure did not affect basal cortisol secretion and the mRNA levels of MC2R and P450scc, while StAR gene expression was significantly reduced. Cadmium exposure significantly suppressed ACTH-stimulated cortisol production in a dose-related fashion. This cadmium-mediated suppression in corticosteroidogenesis corresponded with a significant reduction in MC2R, StAR and P450scc mRNA levels in trout head kidney slices. The inhibition of ACTH-stimulated cortisol production and suppression of genes involved in corticosteroidogenesis by cadmium were completely abolished in the presence of 8-Bromo-cAMP (a cAMP analog). Overall, cadmium disrupts the expression of genes critical for corticosteroid biosynthesis in rainbow trout head kidney slices. However, the rescue of cortisol production as well as StAR and P450scc gene expressions by cAMP analog suggests that cadmium impact occurs upstream of cAMP production. We propose that MC2R signaling, the primary step in ACTH-induced cortocosteroidogenesis, is a key target for cadmium-mediated disruption of

  20. Cadmium detoxification processes in the digestive gland of cephalopods in relation to accumulated cadmium concentrations

    Bustamante, Paco; Cosson, Richard; Gallien, Isabelle; Caurant, Florence; Miramand, Pierre

    2002-01-01

    International audience The high concentrations of cadmium recorded in the digestive gland of cephalopods from various temperate and subpolar waters suggest that these molluscs have developed efficient cadmium detoxification mechanisms. The subcellular distribution of cadmium in the digestive gland cells was investigated in seven cephalopod species from the Bay of Biscay (France) and the Faroe Islands. In most species, cadmium was mainly found in the cytosolic fraction of the digestive glan...

  1. Cadmium content of plants as affected by soil cadmium concentration

    Lehoczky, E. [Pannon Univ. of Agricultural Sciences, Keszthely (Hungary); Szabados, I.; Marth, P. [Plant Health and Soil Conservation Station, Higany (Hungary)

    1996-12-31

    Pot experiments were conducted in greenhouse conditions to study the effects of increasing cadmium (Cd) levels on biomass production and Cd contents in corn, (Zea mays L.), garlic (Allium sativum L.), and spinach (Spinacia oleracea L.). Plants were grown in two soil types: Eutric cambisol soil and A gleyic luvisol soil. Spinach proved to be the most sensitive to Cd treatments as its biomass considerably decreased with the increasing Cd levels. Cadmium contents of the three crops increased with increasing levels of Cd applications. Statistical differences were observed in the Cd contents of crops depending on soil type. With the same Cd rates, Cd tissue concentration of test plants grown in the strongly acidic Gleyic luvisol soil were many times higher than that of plants grown in a neutral Eutric cambisol soil. 14 refs., 4 tabs.

  2. Acute Bronchitis

    ... of bronchitis: acute and chronic. Most cases of acute bronchitis get better within several days. But your cough ... that cause colds and the flu often cause acute bronchitis. These viruses spread through the air when people ...

  3. Cadmium-induced Cancers in Animals and in Humans

    Huff, James; Lunn, Ruth M.; Waalkes, Michael P.; Tomatis, Lorenzo; Infante, Peter F.

    2007-01-01

    Discovered in the early 1800s, the use of cadmium and various cadmium salts started to become industrially important near the close of the 19th century, rapidly thereafter began to flourish, yet has diminished more recently. Most cadmium used in the United States is a byproduct from the smelting of zinc, lead, or copper ores, and is used to manufacture batteries. Carcinogenic activity of cadmium was discovered first in animals and only subsequently in humans. Cadmium and cadmium compounds hav...

  4. Cadmium Exposure and Pancreatic Cancer in South Louisiana

    Luckett, Brian G.; L. Joseph Su; Rood, Jennifer C.; Elizabeth T. H. Fontham

    2012-01-01

    Cadmium has been hypothesized to be a pancreatic carcinogen. We test the hypothesis that cadmium exposure is a risk factor for pancreatic cancer with a population-based case-control study sampled from a population with persistently high rates of pancreatic cancer (south Louisiana). We tested potential dietary and nondietary sources of cadmium for their association with urinary cadmium concentrations which reflect long-term exposure to cadmium due to the accumulation of cadmium in the kidney c...

  5. Fumed silica nanoparticle mediated biomimicry for optimal cell-material interactions for artificial organ development.

    de Mel, Achala; Ramesh, Bala; Scurr, David J; Alexander, Morgan R; Hamilton, George; Birchall, Martin; Seifalian, Alexander M

    2014-03-01

    Replacement of irreversibly damaged organs due to chronic disease, with suitable tissue engineered implants is now a familiar area of interest to clinicians and multidisciplinary scientists. Ideal tissue engineering approaches require scaffolds to be tailor made to mimic physiological environments of interest with specific surface topographical and biological properties for optimal cell-material interactions. This study demonstrates a single-step procedure for inducing biomimicry in a novel nanocomposite base material scaffold, to re-create the extracellular matrix, which is required for stem cell integration and differentiation to mature cells. Fumed silica nanoparticle mediated procedure of scaffold functionalization, can be potentially adapted with multiple bioactive molecules to induce cellular biomimicry, in the development human organs. The proposed nanocomposite materials already in patients for number of implants, including world first synthetic trachea, tear ducts and vascular bypass graft. PMID:24243739

  6. Nanocomposites with fumed silica/poly(vinyl pyrrolidone) prepared at a low content of solvents

    Gun' ko, V.M. [Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kiev (Ukraine)]. E-mail: gun@voliacable.com; Voronin, E.F. [Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kiev (Ukraine); Nosach, L.V. [Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kiev (Ukraine); Pakhlov, E.M. [Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kiev (Ukraine); Voronina, O.E. [Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kiev (Ukraine); Tufts University, 62 Talbot Avenue, Medford, MA 02155 (United States); Guzenko, N.V. [Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kiev (Ukraine); Kazakova, O.A. [Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kiev (Ukraine); Leboda, R. [Faculty of Chemistry, Maria Curie-Sklodowska University, 20031 Lublin (Poland); Skubiszewska-Zieba, J. [Faculty of Chemistry, Maria Curie-Sklodowska University, 20031 Lublin (Poland)

    2006-12-30

    Highly disperse nanocomposites with fumed silica/poly(vinyl pyrrolidone) (PVP) prepared using different methods were studied by infrared spectroscopy, adsorption, and quantum chemistry methods. Low amounts of water or ethanol (30 wt.% with respect to the silica content) promote appropriate distribution of PVP on silica particles. The use of ethanol leads to a smaller loss of the specific surface area (S {sub BET}) than in the case of water used as a solvent. On PVP distribution on a silica surface, treatment of the system in a pseudo-liquid state reactor (PLSR) provides slightly better results (a lower loss in S {sub BET}) in comparison with mechanochemical activation (MCA) in a ball mill at the PVP monolayer coverage. An increase in the activation time to 6-9 h leads to an increase in the vertical bar {delta}S {sub BET}/S {sub BET} vertical bar value to 0.29-0.35 for both treatment methods.

  7. Durability and Strength Properties on High Performance Self Compacting Concrete with GGBS and Silica Fumes

    J. M.Srishaila

    2014-06-01

    Full Text Available This study on the experimental investigation on strength aspects like compressive strength, flexural strength and split tensile strength, and durability aspects like rapid chloride penetration test(RCPT of high performance self-compacting concrete with different mineral admixtures . Initials tests like slump test, L-box test, U-box test and T50 test will be carried out. The methodology adopted here is Ground granulated blast furnace slag (GGBS which is replaced partially by cement at 10%, 20% and 30% and silica fumes(SF by 3%, 6%, 9% in combination with Portland cement and the performance is measured and compared. The influence of mineral admixtures on the workability, mechanical strength and durability aspects of self-compacting concrete are studied. The mix proportion is obtained as per the guidelines given by European Federation of producers and contractors of special products for structure.

  8. Disposal of low concentration fume with solid waste modified by microwave.

    He, Zhijun; Jin, Yonglong; Zhang, Junhong; Liu, Jihui; Guan, Zhigang

    2011-06-01

    The feasibilities of two solid waste, smelting slag and fly ash, as desulfurization and denitrogenation absorbents and additives by microwave were investigated. The influences of operating parameters were also studied. Under the optimal operating conditions, the removal efficiencies of 65.9% and 65.0% were achieved for S02 and NOx respectively. Scanning Electron Microscope and energy dispersive spectroscopy were employed to study the micro-area characteristics of fly ash, smelting slag absorbent and the spent absorbent. In addition, the mechanisms of simultaneous removal of S02 and NOx were investigated. The microwave-modified absorbent in fact played the role of solid catalyst in the process of S02 and NOx treatment from fume. S02 and NOx were oxidized because of microwave-modified absorbent catalytic effect. PMID:25084580

  9. Formulation of a grease from spent bleaching earth, waste cooking oil and fumed silica as additives

    The study is to formulate new multi-purpose grease from industrial wastes. In this study we intent to use waste cooking oil and spent bleaching earth as a main ingredients for the grease formulation. Additives such as fumed silica, molybdenum disulphide and other type of additives are introduced to improve the properties of the grease. The best percentage of waste cooking oil, spent bleaching earth and additives added is determined (w/w) during this study to produces the best consistency through penetration test based on NGLI standard. Other properties being determined include drop point, oxidation stability, and oil separation test through ASTM method. From result obtained, some necessary modification and additives addition into spent bleaching earth and waste cooking oil can produce new multi-purpose based grease that can be commercialized. (author)

  10. Nanocomposites with fumed silica/poly(vinyl pyrrolidone) prepared at a low content of solvents

    Highly disperse nanocomposites with fumed silica/poly(vinyl pyrrolidone) (PVP) prepared using different methods were studied by infrared spectroscopy, adsorption, and quantum chemistry methods. Low amounts of water or ethanol (30 wt.% with respect to the silica content) promote appropriate distribution of PVP on silica particles. The use of ethanol leads to a smaller loss of the specific surface area (S BET) than in the case of water used as a solvent. On PVP distribution on a silica surface, treatment of the system in a pseudo-liquid state reactor (PLSR) provides slightly better results (a lower loss in S BET) in comparison with mechanochemical activation (MCA) in a ball mill at the PVP monolayer coverage. An increase in the activation time to 6-9 h leads to an increase in the vertical bar ΔS BET/S BET vertical bar value to 0.29-0.35 for both treatment methods

  11. Properties of cement-fly ash grout admixed with bentonite, silica fume, or organic fiber

    A detailed laboratory study was conducted to investigate the properties of cement-fly ash grout mixtures as barriers for isolation of hazardous and low-level radioactive wastes. In the grout studied, fly ash was used to replace 30 percent by mass of cement. Three additives including bentonite, silica fume, and polypropylene fiber were used individually in the grout mixes to improve the properties of the grouts in different aspects. The flowability, bleeding, and setting time of freshly mixed grouts were determined; and the unconfined compressive strength, pore size distribution, and water permeability were determined for hardened grouts at various curing durations up to 120 days. Finally, the durability of cement-fly ash grouts was carefully examined in terms of the changes in their physical properties after different levels of exposure to sulfate attack and wet-dry cycles

  12. Aluminium-based Coatings for Cadmium Replacement

    Cardilli , Emanuele

    2008-01-01

    Cadmium electroplating is widely used in the aerospace industry for the corrosion protection of high strength steels. Cadmium is also used as compatible coating to reduce the galvanic corrosion generated in the assembly of components manufactured with different materials. However, environmental and safety concerns over the high toxicity of cadmium has led to the investigation of suitable replacements. Aluminium coatings are promising coatings for the replacement of electropl...

  13. Zone refining of cadmium and related characterization

    N R Munirathnam; D S Prasad; Ch Sudheer; J V Rao; T L Prakash

    2005-06-01

    We present the zone refining results of cadmium using horizontal resistive zone refiner under constant flow of moisture free hydrogen gas. The boron impurity in cadmium can be avoided using quartz (GE 214 grade) boat in lieu of high pure graphite boat. The analytical results using inductively coupled plasma optical emission spectrometry (ICPOES) show that majority of the impurities are less than the detection limits. Comparatively, zinc is the most difficult impurity element to remove in cadmium matrix by zone refining.

  14. Interfacial phenomena at a surface of individual and complex fumed nanooxides.

    Gun'ko, V M; Turov, V V; Zarko, V I; Goncharuk, O V; Pakhlov, E M; Skubiszewska-Zięba, J; Blitz, J P

    2016-09-01

    Investigations of interfacial and temperature behaviors of nonpolar and polar adsorbates interacting with individual and complex fumed metal or metalloid oxides (FMO), initial and subjected to various treatments or chemical functionalization and compared to such porous adsorbents as silica gels, precipitated silica, mesoporous ordered silicas, filled polymeric composites, were analyzed. Complex nanooxides include core-shell nanoparticles, CSNP (50-200nm in size) with titania or alumina cores and silica or alumina shells in contrast to simple and smaller nanoparticles of individual FMO. CSNP could be destroyed under high-pressure cryogelation (HPCG) or mechanochemical activation (MCA). These treatments affect the structure of aggregates of nanoparticles and agglomerates of aggregates, resulting in their becoming more compacted. The analysis shows that complex FMO could be more sensitive to external actions than simple nanooxides such as fumed silica. Any treatment of 'soft' FMO affects the interfacial and temperature behaviors of polar and nonpolar adsorbates. Rearrangement of secondary particles and surface functionalization affects the freezing-melting point depression of adsorbates. For some adsorbates, open hysteresis loops became readily apparent in adsorption-desorption isotherms. Clustering of adsorbates bound in textural pores in aggregates of nanoparticles (i.e., voids between nanoparticles in secondary structures) causes reduced changes in enthalpy during phase transitions (freezing, fusion, evaporation). Freezing point depression and melting point elevation cause significant hysteresis freezing-melting effects for adsorbates bound to FMO in the textural pores. Relaxation phenomena for both low- and high-molecular weight adsorbates or filled polymeric composites are affected by the morphology of primary particles, structural organization of secondary particles of differently treated or functionalized FMO, content of adsorbates, co-adsorption order, and

  15. The effect of silica fume and metakaolin on glass-fibre reinforced concrete (GRC ageing

    Enfedaque Díaz, A.

    2010-12-01

    Full Text Available The deterioration of the mechanical properties of glassfibre reinforced concrete (GRC over time rules out the use of this material in load-bearing structures. While one possible solution to this problem is the addition of pozzolans or metakaolin to the cement mortar, the amounts needed to ensure GRC integrity raise its price to non-competitive levels. Experimental research has been conducted to analyze whether the addition of small amounts of silica fume or metakaolin can prevent or mitigate the ageing issue. Unfortunately, the findings indicate that the addition of small proportions of metakaolin or silica fume to GRC are ineffective in improving its long-term performance.

    Para el uso del mortero de cemento reforzado con fibras de vidrio (GRC en estructuras portantes se han de solucionar los problemas de reducción de las propiedades mecánicas que aparecen con el paso del tiempo. Estos problemas pueden ser solucionados mediante la adición de puzolanas o de metacaolín, a la pasta de mortero de cemento. Sin embargo, la cantidad de metacaolín que ha de ser añadida es elevada y el precio del GRC fabricado está fuera del mercado. Se ha realizado una campaña experimental que analiza si la adición de humo de sílice o de metacaolín en proporciones reducidas consigue evitar o paliar el problema del envejecimiento, que supone un freno al uso del GRC en elementos estructurales. Desgraciadamente, los resultados experimentales muestran que proporciones bajas de metacaolín o de humo de sílice no son efectivas para reducir el problema de pérdida de propiedades mecánicas.

  16. Exposure to welding fumes and lower airway infection with Streptococcus pneumoniae

    Suri, Reetika; Periselneris, Jimstan; Lanone, Sophie; Zeidler-Erdely, Patti C.; Melton, Geoffrey; Palmer, Keith T.; Andujar, Pascal; Antonini, James M.; Cohignac, Vanessa; Erdely, Aaron; Jose, Ricardo J.; Mudway, Ian; Brown, Jeremy; Grigg, Jonathan

    2015-01-01

    Background Welders are at increased risk of pneumococcal pneumonia. The mechanism for this association is not known. The capacity of pneumococci to adhere to and infect lower airway cells is mediated by host-expressed platelet-activating factor receptor (PAFR). Objective We sought to assess the effect of mild steel welding fumes (MS-WF) on PAFR-dependent pneumococcal adhesion and infection to human airway cells in vitro and on pneumococcal airway infection in a mouse model. Methods The oxidative potential of MS-WF was assessed by their capacity to reduce antioxidants in vitro. Pneumococcal adhesion and infection of A549, BEAS-2B, and primary human bronchial airway cells were assessed by means of quantitative bacterial culture and expressed as colony-forming units (CFU). After intranasal instillation of MS-WF, mice were infected with Streptococcus pneumoniae, and bronchoalveolar lavage fluid (BALF) and lung CFU values were determined. PAFR protein levels were assessed by using immunofluorescence and immunohistochemistry, and PAFR mRNA expression was assessed by using quantitative PCR. PAFR was blocked by CV-3988, and oxidative stress was attenuated by N-acetylcysteine. Results: MS-WF exhibited high oxidative potential. In A549 and BEAS-2B cells MS-WF increased pneumococcal adhesion and infection and PAFR protein expression. Both CV-3988 and N-acetylcysteine reduced MS-WF–stimulated pneumococcal adhesion and infection of airway cells. MS-WF increased mouse lung PAFR mRNA expression and increased BALF and lung pneumococcal CFU values. In MS-WF–exposed mice CV-3988 reduced BALF CFU values. Conclusions Hypersusceptibility of welders to pneumococcal pneumonia is in part mediated by the capacity of welding fumes to increase PAFR-dependent pneumococcal adhesion and infection of lower airway cells. PMID:26277596

  17. A Cross-Sectional Study of the Cardiovascular Effects of Welding Fumes.

    Huiqi Li

    Full Text Available Occupational exposure to particulate air pollution has been associated with an increased risk of cardiovascular disease. However, the risk to welders working today remains unclear. We aimed to elucidate the cardiovascular effects of exposure to welding fumes.In a cross-sectional study, structured interviews and biological sampling were conducted for 101 welders and 127 controls (all non-smoking males from southern Sweden. Personal breathing zone sampling of respirable dust was performed. Blood pressure (BP and endothelial function (using peripheral arterial tonometry were measured. Plasma and serum samples were collected from peripheral blood for measurement of C-reactive protein, low-density lipoprotein, homocysteine, serum amyloid A, and cytokines.Welders were exposed to 10-fold higher levels of particles than controls. Welders had significantly higher BP compared to controls, an average of 5 mm Hg higher systolic and diastolic BP (P ≤ 0.001. IL-8 was 3.4 ng/L higher in welders (P=0.010. Years working as a welder were significantly associated with increased BP (β=0.35, 95%CI 0.13 - 0.58, P=0.0024 for systolic BP; β=0.32, 95%CI 0.16 - 0.48, P<0.001 for diastolic BP, adjusted for BMI but exposure to respirable dust was not associated with BP. No clear associations occurred between welding and endothelial function, or other effect markers.A modest increase in BP was found among welders compared to controls suggesting that low-to-moderate exposure to welding fumes remains a risk factor for cardiovascular disease.

  18. Bioavailability of cadmium from linseed and cocoa

    Hansen, Max; Rasmussen, Rie Romme; Sloth, Jens Jørgen

    2014-01-01

    The exposure of the European population to cadmium from food is high compared with the tolerable weekly intake of 2.5 μg/kg bodyweight set by EFSA in 2009. Only few studies on the bioavailability of cadmium from different food sources has been performed but this information in very important for the food authorities in order to give correct advises to the population. The aim of this study was to investigate the bioavailability of cadmium from whole linseed, crushed linseed, cocoa and cadmium ...

  19. Lead and cadmium in food

    The amounts of lead and cadmium produced and processed in these days are considerable. As a result, our environment is increasingly polluted by heavy metals and industrial installations, motor vehicles or incinerating plants appear to be among the main culprits here. Air and water are the media permitting the entry of heavy metals into our natural environment where they accumulate in the soil and then gradually migrate into the plants. Their further transport in the food constitutes the third step in the environmental spread of heavy metals. The consumption of muscle and organ meats, of vegetables, fruits, canned food and drinking water is unavoidably associated with some ingestion of lead and cadmium. The degree to which they are taken up and stored in different tissues is determined by absorption properties and the nutritional state of the organism. Cadmium tends to accumulate in the kidneys, lead is mainly stored in the bones. A continuously increasing uptake finally results in health injuries that range from unspecific complaints to damaged kidneys or bones and disorders of liver function. Children and elderly people are at a particular risk here. The level of food contamination is such that screening for heavy metals must be rigorously carried out once appropriate legal thresholds have been set, which ought to be based on proven detrimental effects of lead and cadmium on our health and also take account of infants and children or any other risk groups, where particular caution must be exercised. It should be pointed out that such thresholds have so far not been determined. (orig./MG)

  20. Historical perspectives on cadmium toxicology

    The first health effects of cadmium (Cd) were reported already in 1858. Respiratory and gastrointestinal symptoms occurred among persons using Cd-containing polishing agent. The first experimental toxicological studies are from 1919. Bone effects and proteinuria in humans were reported in the 1940's. After World War II, a bone disease with fractures and severe pain, the itai-itai disease, a form of Cd-induced renal osteomalacia, was identified in Japan. Subsequently, the toxicokinetics and toxicodynamics of Cd were described including its binding to the protein metallothionein. International warnings of health risks from Cd-pollution were issued in the 1970's. Reproductive and carcinogenic effects were studied at an early stage, but a quantitative assessment of these effects in humans is still subject to considerable uncertainty. The World Health Organization in its International Program on Chemical Safety, WHO/IPCS (1992) (Cadmium. Environmental Health Criteria Document 134, IPCS. WHO, Geneva, 1-280.) identified renal dysfunction as the critical effect and a crude quantitative evaluation was presented. In the 1990's and 2000 several epidemiological studies have reported adverse health effects, sometimes at low environmental exposures to Cd, in population groups in Japan, China, Europe and USA (reviewed in other contributions to the present volume). The early identification of an important role of metallothionein in cadmium toxicology formed the basis for recent studies using biomarkers of susceptibility to development of Cd-related renal dysfunction such as gene expression of metallothionein in peripheral lymphocytes and autoantibodies against metallothionein in blood plasma. Findings in these studies indicate that very low exposure levels to cadmium may give rise to renal dysfunction among sensitive subgroups of human populations such as persons with diabetes.

  1. 64. Study on the DNA damage induced by coal tar pitch fume extracts in rat alveolar macrophage and it's mechanism

    2001-01-01

    The carcinogenic mechanism of coal tar pitch (CTP) as a recognized carcinogen has been studying. It is widely believed that the carcinogenicity of CTP is based on the genotoxicity of CTP. In the process of carcinogenesis caused by extrinsic chemical substance, the DNA damage mainly occurred in the initiation phase. UP to now, the most sensitive detecting endpoint for DNA damage is to detect DNA single strand breaks. The single cell gel electrophoresis has been rapidly becoming a widely used analytical procedure during the last few years, which can detect DNA strand breaks. The method is a fast, relatively inexpensive, easy to perform, non-radioactive, and very sensitive method. This method suits to different tests in vitro or in vivo. Virtually any eukaryotic cell, which could be made into single cell suspensions, can be processed for analysis of DNA damage using the single cell gel electrophoresis. The aim of the study is to investigate the role of DNA damage induced by CTP fume in rat AM, to examine the changes of ROS, MDA and SOD, and to explore the mechanism of DNA damage by CTP fume. The present study is in favor of studying the mechanism of mutagenesis and carcinogenesis induced by CTP. Method: The healthy male Wistar rats were anesthetized intraperitoneally with 40 mg pentobarbital sodium per kilogram of body weight. The animals were exanguinated by excising femoral, and collected the rat alveolar macrophage by Joseph's method. The concentration of AM had been regulated to 1.5×106 cell/ml. AMs, which had been cultured in 24-well culture plate, were divided into 4 groups. These cells were exposured to 5.0 μg/ml extracts of coal tar pitch fume, and contacted with 500 μM, 1 000 μM, and 2 000 μM of GSH respectively. These cells were divided into 4 groups. After incubation 24 hours, the indexes that had been used above were measured. Results: ①The DNA strand breaks induced by coal tar pitch fume extracts: After undergoing electrophoresis, the

  2. Cadmium accumulation by Axonopus compressus (Sw.) P. Beauv and Cyperus rotundas Linn growing in cadmium solution and cadmium-zinc contaminated soil

    Paitip Thiravetyan; Vibol Sao; Woranan Nakbanpote

    2007-01-01

    This research investigated the phyto-remediation potentials of Cyperus rotundas Linn (Nutgrass) and Axonopus compressus (Sw.) P. Beauv (Carpetgrass) for cadmium removal from cadmium solution andcadmium-zinc contaminated soil. Plants growth in the solution showed that cadmium decreased the relative growth rate of both grasses. However, the amount of cadmium accumulated in shoot and root was increasedwith the increase in cadmium concentration and exposure time. Growth in fertile soil mixed with...

  3. Improvement of cadmium phytoremediation after soil inoculation with a cadmium-resistant Micrococcus sp.

    Sangthong, Chirawee; Setkit, Kunchaya; Prapagdee, Benjaphorn

    2016-01-01

    Cadmium-resistant Micrococcus sp. TISTR2221, a plant growth-promoting bacterium, has stimulatory effects on the root lengths of Zea mays L. seedlings under toxic cadmium conditions compared to uninoculated seedlings. The performance of Micrococcus sp. TISTR2221 on promoting growth and cadmium accumulation in Z. mays L. was investigated in a pot experiment. The results indicated that Micrococcus sp. TISTR2221significantly promoted the root length, shoot length, and dry biomass of Z. mays L. transplanted in both uncontaminated and cadmium-contaminated soils. Micrococcus sp. TISTR2221 significantly increased cadmium accumulation in the roots and shoots of Z. mays L. compared to uninoculated plants. At the beginning of the planting period, cadmium accumulated mainly in the shoots. With a prolonged duration of cultivation, cadmium content increased in the roots. As expected, little cadmium was found in maize grains. Soil cadmium was significantly reduced with time, and the highest percentage of cadmium removal was found in the bacterial-inoculated Z. mays L. after transplantation for 6 weeks. We conclude that Micrococcus sp. TISTR2221 is a potent bioaugmenting agent, facilitating cadmium phytoextraction in Z. mays L. PMID:26336850

  4. Acute toxicity of copper and cadmium for piauçu, Leporinus macrocephalus, and curimatã, Prochilodus vimboides = Toxicidade aguda do cobre e do cádmio no piauçu, Leporinus macrocephalus, e no curimatã, Prochilodus vimboides

    Levy Carvalho Gomes; Adriana Regina Chippari-Gomes; Rodrigo Nunes Oss; Luiz Fernando Loureiro Fernandes; Rafael de Almeida Magris

    2009-01-01

    Ninety-six-hour static bioassays were conducted in the laboratory to determine lethal concentrations (96-h LC50) of copper and cadmium for curimatã (Prochilodus vimboides) and piauçu (Leporinus macrocephalus). The 96-h LC50 of copper were 0.047 and 0.090 mg L-1, and of cadmium 3.16 and 7.42 mg L-1 for curimatã and piauçu, respectively. Curimatã is a preferred indigenous species for toxicological studies in the Doce River basin due to its availability in the hatcheries of the region and high s...

  5. The influence of occupational exposure to pesticides, polycyclic aromatic hydrocarbons, diesel exhaust, metal dust, metal fumes, and mineral oil on prostate cancer: a prospective cohort study

    Boers, D; Zeegers, M.; Swaen, G; Kant, I.; van den Brandt, P. A.

    2005-01-01

    Aims: To investigate the relation between exposure to pesticides, polycyclic aromatic hydrocarbons (PAHs), diesel exhaust, metal dust, metal fumes, and mineral oil in relation to prostate cancer incidence in a large prospective study.

  6. Association of lead and cadmium exposure with frailty in US older adults

    García-Esquinas, Esther, E-mail: esthergge@gmail.com [Department of Preventive Medicine and Public Health, School of Medicine, Universidad Autónoma de Madrid/ IdiPAZ, Madrid (Spain); CIBER of Epidemiology and Public Health (CIBERESP), Madrid (Spain); Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD (United States); Navas-Acien, Ana [Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD (United States); Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD (United States); Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD (United States); Pérez-Gómez, Beatriz [CIBER of Epidemiology and Public Health (CIBERESP), Madrid (Spain); Environmental Epidemiology and Cancer Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid (Spain); Artalejo, Fernando Rodríguez [Department of Preventive Medicine and Public Health, School of Medicine, Universidad Autónoma de Madrid/ IdiPAZ, Madrid (Spain); CIBER of Epidemiology and Public Health (CIBERESP), Madrid (Spain)

    2015-02-15

    Background: Environmental lead and cadmium exposure is associated with higher risk of several age-related chronic diseases, including cardiovascular disease, chronic kidney disease and osteoporosis. These diseases may lead to frailty, a geriatric syndrome characterized by diminished physiologic reserve in multiple systems with decreased ability to cope with acute stressors. However, no previous study has evaluated the association between lead or cadmium exposure and frailty. Methods: Cross-sectional study among individuals aged ≥60 years who participated in the third U.S. National Health and Nutrition Examination Survey and had either blood lead (N=5272) or urine cadmium (N=4887) determinations. Frailty was ascertained with a slight modification of the Fried criteria, so that individuals meeting ≥3 of 5 pre-defined criteria (exhaustion, low body weight, low physical activity, weakness and slow walking speed), were considered as frail. The association between lead and cadmium with frailty was evaluated using logistic regression with adjustment for relevant confounders. Results: Median (intertertile range) concentrations of blood lead and urine cadmium were 3.9 µg/dl (2.9–4.9) and 0.62 µg/l (0.41–0.91), respectively. The prevalence of frailty was 7.1%. The adjusted odds ratios (95% confidence interval) of frailty comparing the second and third to the lowest tertile of blood lead were, respectively, 1.40 (0.96–2.04) and 1.75 (1.33–2.31). Lead concentrations were also associated with the frequency of exhaustion, weakness and slowness. The corresponding odds ratios (95% confidence interval) for cadmium were, respectively, 0.97 (0.68–1.39) and 1.55 (1.03–2.32), but this association did not hold after excluding participants with reduced glomerular filtration rate: 0.70 (0.43–1.14) and 1.09 (0.56–2.11), respectively. Conclusions: In the US older adult population, blood lead but not urine cadmium concentrations showed a direct dose

  7. Association of lead and cadmium exposure with frailty in US older adults

    Background: Environmental lead and cadmium exposure is associated with higher risk of several age-related chronic diseases, including cardiovascular disease, chronic kidney disease and osteoporosis. These diseases may lead to frailty, a geriatric syndrome characterized by diminished physiologic reserve in multiple systems with decreased ability to cope with acute stressors. However, no previous study has evaluated the association between lead or cadmium exposure and frailty. Methods: Cross-sectional study among individuals aged ≥60 years who participated in the third U.S. National Health and Nutrition Examination Survey and had either blood lead (N=5272) or urine cadmium (N=4887) determinations. Frailty was ascertained with a slight modification of the Fried criteria, so that individuals meeting ≥3 of 5 pre-defined criteria (exhaustion, low body weight, low physical activity, weakness and slow walking speed), were considered as frail. The association between lead and cadmium with frailty was evaluated using logistic regression with adjustment for relevant confounders. Results: Median (intertertile range) concentrations of blood lead and urine cadmium were 3.9 µg/dl (2.9–4.9) and 0.62 µg/l (0.41–0.91), respectively. The prevalence of frailty was 7.1%. The adjusted odds ratios (95% confidence interval) of frailty comparing the second and third to the lowest tertile of blood lead were, respectively, 1.40 (0.96–2.04) and 1.75 (1.33–2.31). Lead concentrations were also associated with the frequency of exhaustion, weakness and slowness. The corresponding odds ratios (95% confidence interval) for cadmium were, respectively, 0.97 (0.68–1.39) and 1.55 (1.03–2.32), but this association did not hold after excluding participants with reduced glomerular filtration rate: 0.70 (0.43–1.14) and 1.09 (0.56–2.11), respectively. Conclusions: In the US older adult population, blood lead but not urine cadmium concentrations showed a direct dose

  8. Exposure to welding fumes increases lung cancer risk among light smokers but not among heavy smokers: evidence from two case-control studies in Montreal.

    Vallières, Eric; Pintos, Javier; Lavoué, Jérôme; Parent, Marie-Élise; Rachet, Bernard; Siemiatycki, Jack

    2012-08-01

    We investigated relationships between occupational exposure to gas and arc welding fumes and the risk of lung cancer among workers exposed to these agents throughout the spectrum of industries. Two population-based case-control studies were conducted in Montreal. Study I (1979-1986) included 857 cases and 1066 controls, and Study II (1996-2001) comprised 736 cases and 894 controls. Detailed job histories were obtained by interview and evaluated by an expert team of chemist-hygienists to estimate degree of exposure to approximately 300 substances for each job. Gas and arc welding fumes were among the agents evaluated. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) of lung cancer using logistic regression, adjusting for smoking history and other covariates. The two studies provided similar results, so a pooled analysis was conducted. Among all subjects, no significant association was found between lung cancer and gas welding fumes (OR = 1.1; 95% CI = 0.9-1.4) or arc welding fumes (OR = 1.0; 95% CI = 0.8-1.2). However, when restricting attention to light smokers, there was an increased risk of lung cancer in relation to gas welding fumes (OR = 2.9; 95% CI = 1.7-4.8) and arc welding fumes (OR = 2.3; 95% CI = 1.3-3.8), with even higher OR estimates among workers with the highest cumulative exposures. In conclusion, there was no detectable excess risk of lung cancer due to welding fumes among moderate to heavy smokers; but among light smokers we found an excess risk related to both types of welding fumes. PMID:23342253

  9. Cadmium Modulates Biofilm Formation by Staphylococcus epidermidis

    Wu, Xueqing; Santos, Regiane R.; Fink-Gremmels, Johanna

    2015-01-01

    The aim of the study was to evaluate the effect of cadmium exposure on Staphylococcus epidermidis (ATCC 35984) biofilm formation. Bacteria were cultured in the absence or presence of different concentrations (0-50 mu M) of cadmium. Biofilm formation and bacterial viability were assessed. Quantitativ

  10. Cadmium Toxicity to Ringed Seals (Phoca hispida)

    Sonne, Christian; Dietz, R.; Riget, F. F.;

    Cadmium concentrations in kidneys from ringed seals (Phoca hispida) from North West Greenland (Qaanaaq) are high. Concentrations range at level known to induce renal toxic effects (mainly tubulopathy) and demineralisation (osteopenia) of the skeletal system (Fanconi's Syndrome) in humans as well...... the absence of toxic effects of cadmium in ringed seal...

  11. Electrodialytic Removal of Cadmium from Straw Ash

    Hansen, Henrik; Ottosen, Lisbeth M.; Villumsen, Arne;

    1999-01-01

    A problem with flyash from straw and wood combustion is the high level of heavy metals, especially cadmium. Two electrodialytic remediation experiments were carried out on cadmium polluted flyash from straw combustion. The flyash could be cleaned to 1/3 of its initial level after 24 days of...

  12. Interlaboratory comparison survey of the determination of chromium, manganese, iron, titanium in dust and arsenic, cadmium, cobalt and chromium in urine

    This report describes an intercomparison survey based on the Danish External Quality Assessment Scheme (DEQAS). The study was carried out in 1998 for 10 laboratories in a research project on assessment of levels and health effects of airborne particulate matter in mining, metal refining and metal working industries using nuclear and related analytical techniques. The project was co-ordinated by the IAEA. Eight laboratories measured chromium (Cr), manganese (Mn), iron (Fe) and titanium (Ti) in welding fume dust loaded on filters. Six laboratories measured arsenic (As), four laboratories measured cadmium (Cd), five laboratories measured cobalt (Co) and four laboratories measured chromium (Cr) in urine. The target values of the quality control materials were traceable to certified reference materials with respect to Cr in welding fume and As, Cd, Co and Cr in urine. For Mn, Fe and Ti in welding fume the target values were established based on values from reference laboratories and consensus values from several DEQAS rounds. For evaluating the analytical performance the z-score and En number were calculated as recommended in ISO 45. The judgement of laboratories according to the performance scores revealed that few laboratories could maintain an ideal z-score below 3 and an ideal En number below 1. Nearly all participants had a high precision in the reported results. This is a good basis for improvements. The deviations from the target values appear to be systematic, because the deviations for Mn, Fe, Ti in welding dust as well as for As, Cd, Co and Cr in urine were a linear function of the target values (ISO 5725 evaluation). The cause for this bias is unknown at present and might not be the same for all participants. It is necessary to look further into the cause for this bias. Therefore, validation of the methodologies and regularly use of certified reference materials are highly recommended. (author)

  13. Effects of superglue fuming on materials characterization of zip-lock polyethylene bags for route forensic analyses

    Using cyanoacrylate or 'superglue' fuming to develop latent dermatoglyphic prints significantly altered the volatile and semivolatile compounds within the material of polyethylene zip-lock bags. Comparisons of SPME-GC/MS analyses of poly bags obtained before and after application of a glue fuming fingermark-developing technique resulted in markedly different material profiles of the bags. Not only were species added to the chemical composition of a bag, but other compounds that had been initially present were removed. These effects are particularly important for nuclear forensic investigations in the realm of route (pathway) analyses, and may also be of general interest to criminalistics laboratories that examine illicit drugs and their packaging. (author)

  14. Calculation of radiation attenuation coefficients in Portland cements mixed with silica fume, blast furnace slag and natural zeolite

    This paper presents the radiation attenuation coefficients expressed as mass attenuation coefficients for Portland cement, zeolite, blast furnace slag, silica fume and their mixed types in function of the Photon energy over the energy range of 1 keV to 2 MeV. It was observed that different percentages of constituents in cement and cement mixed with different additives such as zeolite, silica fume and blast furnace slag, lead to significant variations in total mass attenuation coefficients. The elemental compositions of samples were analyzed using a wavelength dispersive XRF spectrometer. The calculated values of total mass attenuation coefficients were discussed on the basis of different percentages of constituents of cement and cement mixed with different additives

  15. Molecular and cellular mechanisms of cadmium carcinogenesis

    Cadmium is a heavy metal, which is widely used in industry, affecting human health through occupational and environmental exposure. In mammals, it exerts multiple toxic effects and has been classified as a human carcinogen by the International Agency for Research on Cancer. Cadmium affects cell proliferation, differentiation, apoptosis and other cellular activities. Cd2+ does not catalyze Fenton-type reactions because it does not accept or donate electrons under physiological conditions, and it is only weakly genotoxic. Hence, indirect mechanisms are implicated in the carcinogenicity of cadmium. In this review multiple mechanisms are discussed, such as modulation of gene expression and signal transduction, interference with enzymes of the cellular antioxidant system and generation of reactive oxygen species (ROS), inhibition of DNA repair and DNA methylation, role in apoptosis and disruption of E-cadherin-mediated cell-cell adhesion. Cadmium affects both gene transcription and translation. The major mechanisms of gene induction by cadmium known so far are modulation of cellular signal transduction pathways by enhancement of protein phosphorylation and activation of transcription and translation factors. Cadmium interferes with antioxidant defense mechanisms and stimulates the production of reactive oxygen species, which may act as signaling molecules in the induction of gene expression and apoptosis. The inhibition of DNA repair processes by cadmium represents a mechanism by which cadmium enhances the genotoxicity of other agents and may contribute to the tumor initiation by this metal. The disruption of E-cadherin-mediated cell-cell adhesion by cadmium probably further stimulates the development of tumors. It becomes clear that there exist multiple mechanisms which contribute to the carcinogenicity of cadmium, although the relative weights of these contributions are difficult to estimate

  16. Cadmium blood concentrations in relation to nutrition.

    Krajcovicová-Kudládková, Marica; Ursínyová, Monika; Masánová, Vlasta; Béderová, Alzbeta; Valachovicová, Martina

    2006-09-01

    Cadmium is a toxic element ubiquitous in the environment, which damages biological systems in various ways. The major source of cadmium exposure is food. High cadmium content in the soil leads to high cadmium concentrations in certain plants such as grains (above all surface layers and germs), oil or non-oil seeds, fruit and vegetables. These food commodities are the crucial components of a vegetarian nutrition. Blood cadmium concentrations were measured in two non-smoking population groups: the vegetarian group (n = 80) and the non-vegetarian (control) group of general population on traditional mixed diet (n = 84). The significantly higher blood cadmium content (1.78 +/- 0.22 vs. 0.45 +/- 0.04 microg/l) was measured in vegetarian group. Healthy risk values > 5 microg/l were found in 6 vegetarians vs. no non-vegetarian. The highest cadmium concentration (3.15 +/- 0.77 microg/l) was measured in vegan subgroup (plant food only, n = 10) and that value decreased with increasing animal food consumption (1.75 +/- 0.36 microg/l, lactovegetarian and lactoovovegetarian subgroup/added dairy products and eggs, n = 41/, 1.34 +/- 0.21 microg/I, semivegetarian subgroup /as a previous subgroup and added white meat, n = 291). Risk vegetarians vs. non-risk vegetarians consume significantly higher amounts of whole grain products, grain sprouts and oil seeds. Blood cadmium content is directly influenced by age (r = 0.32, p vegetarianism (r = 0.5, p Vegetarians have significantly higher plasma concentrations of natural antioxidants. The sufficient antioxidative protection against cadmium induced free radical formation in vegetarians may inhibit the harmful effects of greater cadmium intake from plant food. PMID:17152224

  17. Polycyclic aromatic hydrocarbons in ultrafine particles of diesel exhaust fumes – The use of ultrafast liquid chromatography

    Małgorzata Szewczyńska; Małgorzata Pośniak

    2014-01-01

    Background: The article presents the results of the determination of polycyclic aromatic hydrocarbons (PAHs) in the fine particles fraction emitted from 3 types of diesel fuels using ultra-high pressure liquid chromatography. Material and Methods: Samples of diesel Eco, Verwa and Bio exhaust combustion fumes were generated at the model station which consisted of a diesel engine from the 2007 Diesel TDI 2.0. Personal Cascade Sioutas Impactor (PCSI) with Teflon filters was used to collect sampl...

  18. Peculiarities of preparation of cadmium isotopes of high enrichment

    Cascade equipped by gas centrifuges with regard for requirements to structural materials operating with chemically active compounds (dimethylcadmium) was devised for preparation of high-enriched cadmium isotopes. Solutions of such problems as overcoming of isotope memory, compensation of the effect of isotope overlapping, operative analytical accompanying permitted to optimize separation process and to obtain cadmium isotopes of high enrichment degree: cadmium-116 ∼98.9 %, cadmium-114 ∼98.7 %, cadmium-113 ∼93.3 %, cadmium-112 ∼99.1 %, cadmium-110 ∼95.8 %

  19. Barbecue Fumes: An Overlooked Source of Health Hazards in Outdoor Settings?

    Wu, Chen-Chou; Bao, Lian-Jun; Guo, Ying; Li, Shao-Meng; Zeng, Eddy Y

    2015-09-01

    Barbecuing or charcoal-grilling has become part of popular outdoor recreational activities nowadays; however, potential human health hazards through outdoor exposure to barbecue fumes have yet to be adequately quantified. To fill this knowledge gap, atmospheric size-fractioned particle and gaseous samples were collected near an outdoor barbecuing vendor stall (along with charcoal-grilled food items) in Xinjiang of Northwest China with a 10-stage micro-orifice uniform deposit impactor and a polyurethane foam (PUF) sampler and were analyzed for particulate matter and polycyclic aromatic hydrocarbons (PAHs). Exposure to PAHs through inhalation and dermal contact by adult consumers who spent 1 h per day near a charcoal-grilling vendor for a normal meal (lunch or dinner) amounted to a BaP equivalent (BaPeq) dosage of 3.0-77 ng day(-1) (inhalation: 2.8-27 ng day(-1) of BaPeq; dermal contact: 0.2-50 ng day(-1) of BaPeq), comparable to those (22-220 ng day(-1) of BaPeq) from consumer exposure through the consumption of charcoal-grilled meat, assumed to be at the upper limit of 50-150 g. In addition, the potential health risk was in the range of 3.1 × 10(-10) to 1.4 × 10(-4) for people of different age groups with inhalation and dermal contact exposure to PAHs once a day, with a 95% confidence interval (7.2 × 10(-9) to 1.2 × 10(-5)) comparable to the lower limit of the potential cancer risk range (1 × 10(-6) to 1 × 10(-4)). Sensitivity analyses indicated that the area of dermal contact with gaseous contaminants is a critical parameter for risk assessment. These results indicated that outdoor exposure to barbecue fumes (particularly dermal contact) may have become a significant but largely neglected source of health hazards to the general population and should be well-recognized. PMID:26259039

  20. Effects of cadmium on hypoxia-induced expression of hemoglobin and erythropoietin in larval sheepshead minnow, Cyprinodon variegatus

    Dangre, A.J.; Manning, S. [Department of Coastal Sciences, University of Southern Mississippi, 703 East Beach Drive, Ocean Springs, MS 39564 (United States); Brouwer, M., E-mail: marius.brouwer@usm.edu [Department of Coastal Sciences, University of Southern Mississippi, 703 East Beach Drive, Ocean Springs, MS 39564 (United States)

    2010-08-15

    Hypoxia and toxic metals are two common stressors found in the estuarine environment. To date little information is available on the combined effects of these stressors on early larval development in fish. We investigated the effect of cadmium and hypoxia exposure alone as well in combination on larval Cyprinodon variegatus. The LC{sub 10} for cadmium was determined to be 0.3 ppm in a 96 h acute exposure. This concentration was used in all studies. Cadmium in larvae increased significantly with exposure time (1, 3, 5 and 7 days post-hatch). The increase was proportional to body weight and not affected by hypoxia. Cadmium responsive genes were identified by suppression subtractive hybridization (SSH) in Cyprinodonvariegatus larvae after exposure to cadmium for 1, 3, 5 and 7 days. We obtained over 700 sequences from the cadmium cDNA library. Blast search of ESTs suggested that cadmium modulates multiple physiological processes. Pertinent to this study, cadmium was found to down-regulate both embryonic {alpha} and {beta} globin, which are expressed in erythrocytes generated during the first, or primitive, wave of erythropoiesis in teleosts. Hemoglobin (Hb) and erythropoietin (Epo) (the hormone that promotes red blood cell production) are known hypoxia-inducible genes. To explore the possibility that cadmium might offset the hypoxia-induced expression of Hb and Epo, we investigated the expression of both genes following hypoxia, cadmium and combined exposures for 1, 3, 5 and 7 days post-hatch. Since Epo had not yet been identified in C. variegatus we first successfully cloned a partial coding sequence of the C. variegatus hormone. Subsequent studies revealed that expression levels of Hb and Epo remained unchanged in the normoxic controls during the time course of the study. Hypoxia increased Epo expression relative to normoxic controls, on days 3, 5 and 7, while cadmium in hypoxia inhibited the increase. Only the changes on days 5 and 7 were statistically significant

  1. Effects of cadmium on hypoxia-induced expression of hemoglobin and erythropoietin in larval sheepshead minnow, Cyprinodon variegatus

    Hypoxia and toxic metals are two common stressors found in the estuarine environment. To date little information is available on the combined effects of these stressors on early larval development in fish. We investigated the effect of cadmium and hypoxia exposure alone as well in combination on larval Cyprinodon variegatus. The LC10 for cadmium was determined to be 0.3 ppm in a 96 h acute exposure. This concentration was used in all studies. Cadmium in larvae increased significantly with exposure time (1, 3, 5 and 7 days post-hatch). The increase was proportional to body weight and not affected by hypoxia. Cadmium responsive genes were identified by suppression subtractive hybridization (SSH) in Cyprinodonvariegatus larvae after exposure to cadmium for 1, 3, 5 and 7 days. We obtained over 700 sequences from the cadmium cDNA library. Blast search of ESTs suggested that cadmium modulates multiple physiological processes. Pertinent to this study, cadmium was found to down-regulate both embryonic α and β globin, which are expressed in erythrocytes generated during the first, or primitive, wave of erythropoiesis in teleosts. Hemoglobin (Hb) and erythropoietin (Epo) (the hormone that promotes red blood cell production) are known hypoxia-inducible genes. To explore the possibility that cadmium might offset the hypoxia-induced expression of Hb and Epo, we investigated the expression of both genes following hypoxia, cadmium and combined exposures for 1, 3, 5 and 7 days post-hatch. Since Epo had not yet been identified in C. variegatus we first successfully cloned a partial coding sequence of the C. variegatus hormone. Subsequent studies revealed that expression levels of Hb and Epo remained unchanged in the normoxic controls during the time course of the study. Hypoxia increased Epo expression relative to normoxic controls, on days 3, 5 and 7, while cadmium in hypoxia inhibited the increase. Only the changes on days 5 and 7 were statistically significant. Hypoxia also

  2. An Accelerated Test Method of Simultaneous Carbonation and Chloride Ion Ingress: Durability of Silica Fume Concrete in Severe Environments

    S. A. Ghahari

    2016-01-01

    Full Text Available The effects of simultaneous carbonation and chloride ion attack on mechanical characteristics and durability of concrete containing silica fume have been investigated through an accelerated test method. Specimens containing different amounts of silica fume were maintained in an apparatus in which carbon dioxide pressure and concentration and relative humidity were kept constant, and wetting and drying cycles in saline water were applied. Surface resistivity, sorptivity, CO2 consumption, and carbonation and chloride ion ingress depths measurements were taken. Phase change due to carbonation and chloride ion attack was monitored by XRD analysis, and microstructures and interfacial transition zones were studied by implementing SEM as well as mercury intrusion porosimetry. It was expected to have a synergistic effect in the tidal zone where simultaneous carbonation and chloride ion attack happen. However, the observed reduced surface resistivity, compared to specimens maintained in CO2 gas, could be due to the moisture that is available near the surface, hindering CO2 from penetrating into the pores of the specimens. Moreover, the porosity analysis of the specimens showed that the sample containing silica fume cured in the tidal zone had 50.1% less total porosity than the plain cement paste cured in the same condition.

  3. Development of UHPC Mixtures Utilizing Natural and Industrial Waste Materials as Partial Replacements of Silica Fume and Sand

    Shamsad Ahmad

    2014-01-01

    Full Text Available In the exploratory study presented in this paper, an attempt was made to develop different mixtures of ultrahigh performance concrete (UHPC using various locally available natural and industrial waste materials as partial replacements of silica fume and sand. Materials such as natural pozzolana (NP, fly ash (FA, limestone powder (LSP, cement kiln dust (CKD, and pulverized steel slag (PSS, all of which are abundantly available in Saudi Arabia at little or no cost, were employed in the development of the UHPC mixtures. A base mixture of UHPC without replacement of silica fume or sand was selected and a total of 24 trial mixtures of UHPC were prepared using different percentages of NP, FA, LSP, CKD, and PSS, partially replacing the silica fume and sand. Flow and 28-d compressive strength of each UHPC mixture were determined to finally select those mixtures, which satisfied the minimum flow and strength criteria of UHPC. The test results showed that the utilization of NP, FA, LSP, CKD, and PSS in production of UHPC is possible with acceptable flow and strength. A total of 10 UHPC mixtures were identified with flow and strength equal to or more than the minimum required.

  4. Toxicity prediction of binary combinations of cadmium, carbendazim and low dissolved oxygen on Daphnia magna

    Ferreira, Abel L.G. [Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro (Portugal)], E-mail: abel@ua.pt; Loureiro, Susana; Soares, Amadeu M.V.M. [Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro (Portugal)

    2008-08-11

    Environmental contamination is often characterised by a combination of stress factors of various sources (biological, physical and chemical). The predictability of their joint effects is an important stage in environmental risk assessment procedures. In this study, the two main conceptual models for mixture evaluation based on the effect of individual compounds, concentration addition (CA) and independent action (IA) and deviations to synergism/antagonism, 'dose ratio' and 'dose level' dependency were used. The single and combined effects of cadmium, carbendazim and low dissolved oxygen levels were assayed for life-cycle parameters (survival and feeding) of the water flea Daphnia magna Straus. The results of single exposures revealed an increase of acute and chronic toxicity as concentrations of cadmium and carbendazim increases. At low dissolved oxygen levels both survival and feeding parameters were significantly affected (P {<=} 0.05). In the acute mixture exposure of cadmium and carbendazim a 'dose ratio' dependency was observed with a higher toxicity when cadmium was dominant whereas at high concentrations of carbendazim a lower effect on survival was observed. At chronic exposures an antagonistic deviation from IA model was observed for this mixture. The IA model showed to be adequate for toxicity prediction on acute exposure combinations with low DO levels where a synergistic behaviour was observed. However, at sublethal exposures IA and CA models failed by underestimation. Validation from toxicokinetic and toxicodynamic modelling studies should be made in the future as a way to understand toxicological pathways involved in complex mixture/combination exposures.

  5. Acute Pancreatitis and Pregnancy

    ... Acute Pancreatitis > Acute Pancreatitis and Pregnancy test Acute Pancreatitis and Pregnancy Timothy Gardner, MD Acute pancreatitis is ... of acute pancreatitis in pregnancy. Reasons for Acute Pancreatitis and Pregnancy While acute pancreatitis is responsible for ...

  6. Comparative Genotoxicity of Cadmium and Lead in Earthworm Coelomocytes

    Ptumporn Muangphra

    2011-01-01

    Full Text Available To determine genotoxicity to coelomocytes, Pheretima peguana earthworms were exposed in filter paper studies to cadmium (Cd and lead (Pb for 48 h, at concentrations less than the LC10—Cd: 0.09, 0.19, 0.38, 0.75, and 1.50 μg cm−2; Pb: 1.65, 3.29, 6.58, 13.16, and 26.32 μg cm−2. For Cd at 0.75 μg cm−2, in the micronucleus test (detects chromosomal aberrations, significant increases (<.05 in micronuclei and binucleate cells were observed, and in the comet assay (detects DNA single-strand breaks, tail DNA% was significantly increased. Lead was less toxic with minimal effects on DNA, but the binucleates were significantly increased by Pb at 3.29 μg cm−2. This study shows that Cd is more acutely toxic and sublethally genotoxic than Pb to P. peguana. Cadmium caused chromosomal aberrations and DNA single-strand breaks at 45% of the LC10 concentration. Lead, in contrast, did not induce DNA damage but caused cytokinesis defects.

  7. Role of oxidative stress in cadmium toxicity and carcinogenesis

    Cadmium (Cd) is a toxic metal, targeting the lung, liver, kidney, and testes following acute intoxication, and causing nephrotoxicity, immunotoxicity, osteotoxicity and tumors after prolonged exposures. Reactive oxygen species (ROS) are often implicated in Cd toxicology. This minireview focused on direct evidence for the generation of free radicals in intact animals following acute Cd overload and discussed the association of ROS in chronic Cd toxicity and carcinogenesis. Cd-generated superoxide anion, hydrogen peroxide, and hydroxyl radicals in vivo have been detected by the electron spin resonance spectra, which are often accompanied by activation of redox sensitive transcription factors (e.g., NF-κB, AP-1 and Nrf2) and alteration of ROS-related gene expression. It is generally agreed upon that oxidative stress plays important roles in acute Cd poisoning. However, following long-term Cd exposure at environmentally-relevant low levels, direct evidence for oxidative stress is often obscure. Alterations in ROS-related gene expression during chronic exposures are also less significant compared to acute Cd poisoning. This is probably due to induced adaptation mechanisms (e.g., metallothionein and glutathione) following chronic Cd exposures, which in turn diminish Cd-induced oxidative stress. In chronic Cd-transformed cells, less ROS signals are detected with fluorescence probes. Acquired apoptotic tolerance renders damaged cells to proliferate with inherent oxidative DNA lesions, potentially leading to tumorigenesis. Thus, ROS are generated following acute Cd overload and play important roles in tissue damage. Adaptation to chronic Cd exposure reduces ROS production, but acquired Cd tolerance with aberrant gene expression plays important roles in chronic Cd toxicity and carcinogenesis.

  8. Response of Saccharomyces cerevisiae to cadmium stress

    Moreira, Luciana Mara Costa; Ribeiro, Frederico Haddad; Neves, Maria Jose [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Radiobiologia], e-mail: luamatu@uol.com.br; Porto, Barbara Abranches Araujo; Amaral, Angela M.; Menezes, Maria Angela B.C. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Lab. de Ativacao Neutronica], e-mail: menezes@cdtn.br; Rosa, Carlos Augusto [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Microbiologia], e-mail: carlrosa@icb.ufmg

    2009-07-01

    The intensification of industrial activity has been greatly contributing with the increase of heavy metals in the environment. Among these heavy metals, cadmium becomes a serious pervasive environmental pollutant. The cadmium is a heavy metal with no biological function, very toxic and carcinogenic at low concentrations. The toxicity of cadmium and several other metals can be mainly attributed to the multiplicity of coordination complexes and clusters that they can form. Some aspects of the cellular response to cadmium were extensively investigated in the yeast Saccharomyces cerevisiae. The primary site of interaction between many toxic metals and microbial cells is the plasma membrane. Plasma-membrane permeabilisation has been reported in a variety of microorganisms following cadmium exposure, and is considered one mechanism of cadmium toxicity in the yeast. In this work, using the yeast strain S. cerevisiae W303-WT, we have investigated the relationships between Cd uptake and release of cellular metal ions (K{sup +} and Na{sup +}) using neutron activation technique. The neutron activation was an easy, rapid and suitable technique for doing these metal determinations on yeast cells; was observed the change in morphology of the strains during the process of Cd accumulation, these alterations were observed by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) during incorporation of cadmium. (author)

  9. Investigation of Fumed Silica/Aqueous NaCl Superdielectric Material

    Natalie Jenkins

    2016-02-01

    Full Text Available A constant current charge/discharge protocol which showed fumed silica filled to the point of incipient wetness with aqueous NaCl solution to have dielectric constants >108 over the full range of dielectric thicknesses of 0.38–3.9 mm and discharge times of 0.25–>100 s was studied, making this material another example of a superdielectric. The dielectric constant was impacted by both frequency and thickness. For time to discharge greater than 10 s the dielectric constant for all thicknesses needed to be fairly constant, always >109, although trending higher with increasing thickness. At shorter discharge times the dielectric constant consistently decreased, with decreasing time to discharge. Hence, it is reasonable to suggest that for time to discharge >10 s the dielectric constant at all thicknesses will be greater than 109. This in turn implies an energy density for a 5 micron thick dielectric layer in the order of 350 J/cm3 for discharge times greater than 10 s.

  10. Synergistic hypergolic ignition of blends of dienes and dienophiles with red fuming nitric acid as oxidizer

    Panda, S.P.; Kulkarni, S.G.; Prabhakaran, C.

    1989-04-01

    Synergistic hypergolic ignition of several fuel blends and mixtures with red fuming nitric acid (RFNA) as oxidizer has been reported previously. The liquid fuels consisted of blends of 3-carene, cyclopentadiene, or norbornadiene with cardanol in the weight ratio 70:30 for the first two and 85:15 for norbornadiene. In all these cases, synergism in ignition was believed to be due to the fast and exothermic oligomerization of 3-carene, cyclopentadiene, and norbornadiene in the presence of acid. The exothermicity of the systems was enhanced by the addition of cardanol to the unsaturation of oligomers, leading to the formation of highly oxidizable phenolic ethers. Two more important reactions at the preignition stage were nitration and oxidation of the ethers leading to the production of gaseous combustibles and heat. In this case, an attempt has been made to extend the range of possible preignition reactions by introducing diene-dienophile Diels-Alder cycloaddition with low activation energy by replacing cardanol with furfuryl alcohol or furfurylideneacetone having a furan ring to behave as acid polymerizable dienes in the above systems.

  11. Effects of Fumed and Mesoporous Silica Nanoparticles on the Properties of Sylgard 184 Polydimethylsiloxane

    Junshan Liu

    2015-07-01

    Full Text Available The effects of silica nanoparticles on the properties of a commonly used Sylgard 184 polydimethylsiloxane (PDMS in microfluidics were systemically studied. Two kinds of silica nanoparticles, A380 fumed silica nanoparticles and MCM-41 mesoporous silica nanoparticles, were individually doped into PDMS, and the properties of PDMS with these two different silica nanoparticles were separately tested and compared. The thermal and mechanical stabilities of PDMS were significantly enhanced, and the swelling characteristics were also improved by doping these two kinds of nanoparticles. However, the transparency of PDMS was decreased due to the light scattering by nanoparticles. By contrast, PDMS/MCM-41 nanocomposites showed a lower coefficient of thermal expansion (CTE owing to the mesoporous structure of MCM-41 nanoparticles, while PDMS/A380 nanocomposites showed a larger elastic modulus and better transparency due to the smaller size of A380 nanoparticles. In addition, A380 and MCM-41 nanoparticles had the similar effects on the swelling characteristics of PDMS. The swelling ratio of PDMS in toluene was decreased to 0.68 when the concentration of nanoparticles was 10 wt %.

  12. Nature and morphology of fumed oxides and features of interfacial phenomena

    Gun'ko, V. M.; Zarko, V. I.; Goncharuk, O. V.; Matkovsky, A. K.; Remez, O. S.; Skubiszewska-Zięba, J.; Wojcik, G.; Walusiak, B.; Blitz, J. P.

    2016-03-01

    Individual and complex fumed nanooxides were studied using high-resolution transmission electron microscopy, X-ray diffraction, ultraviolet-visible (UV-vis) spectroscopy, differential scanning calorimetry, nuclear magnetic resonance spectroscopy, adsorption, desorption (evaporation), and quantum chemical methods. For mixed nanooxides in contrast to simple and small nanoparticles of individual silica or titania, complex core-shell nanoparticles (50-200 nm in size) with titania or alumina cores and silica or alumina shells can be destroyed under high-pressure cryogelation (HPCG), mechnochemical activation (MCA) that also affect the structure of aggregates of nanoparticles and agglomerates of aggregates becoming more compacted. This is accompanied by changes in color from white to beige of different tints and changes in the UV-vis spectra in the 300-600 nm range, as well as changes in crystalline structure of alumina. Any treatment of 'soft' nanooxides affects the interfacial behavior of polar and nonpolar adsorbates. For some of them, the hysteresis loops become strongly open. Rearrangement of secondary particles affects the freezing-melting point depression. Clusterization of adsorbates bound in pores causes diminution of heat effects during phase transition (freezing, fusion). Freezing point depression and increasing melting point cause significant hysteresis freezing-melting effects for adsorbates bound to oxide nanoparticles. The study shows that complex nanooxides can be more sensitive to external actions than simple nanooxides such as silica.

  13. Chemical and physical characterisation of welding fume particles for distinguishing from gunshot residue.

    Brożek-Mucha, Zuzanna

    2015-09-01

    Spherical particles produced by firearms loaded with a traditional ammunition reveal characteristic elemental contents and so their identification may provide a significant evidence in criminal investigations. With the advent of modern technologies in manufacturing ammunition, which replace toxic compounds of lead, antimony and barium in the primer mixture by elements and compounds such as powdered aluminium, titanium, amorphous boron or calcium silicide, differentiation between gunshot residue and morphologically similar particles originating from other anthropogenic or natural sources becomes more difficult. This work provides a chemical and morphological characterisation of welding fume particles originating from both the core and the covering of electrodes used in popular manners of welding steel and aluminium alloy constructions. With the use of scanning electron microscopy and energy dispersive X-ray spectrometry it has been established that single spherules containing aluminium, titanium or a set of such elements as aluminium, silicon, potassium and calcium may occur in result of welding processes, however, they are accompanied by great numbers of iron and iron oxide spherules. Thus, with this analytical method a population of welding particles can be distinguished from a population of gunshot residue originating from a modern type of ammunition, but a special care has to be taken when assessing the evidential value of single or few spherules consisting from light elements being detected in result of the search for gunshot residue for forensic purposes. PMID:26188699

  14. Bronchitis - acute

    ... sharing features on this page, please enable JavaScript. Acute bronchitis is swelling and inflammation in the main passages ... present only for a short time. Causes When acute bronchitis occurs, it almost always comes after having a ...

  15. Bronchitis - acute

    Acute bronchitis is swelling and inflammation in the main passages that carry air to the lungs. The swelling narrows ... makes it harder to breathe. Another symptom of bronchitis is a cough. Acute means the symptoms have ...

  16. Acute Bronchitis

    Bronchitis is an inflammation of the bronchial tubes, the airways that carry air to your lungs. It ... chest tightness. There are two main types of bronchitis: acute and chronic. Most cases of acute bronchitis ...

  17. Acute pancreatitis

    Bo-Guang Fan; Åke Andrén-Sandberg

    2010-01-01

    Background : Acute pancreatitis continues to be a serious illness, and the patients with acute pancreatitis are at risk to develop different complications from ongoing pancreatic inflammation. Aims : The present review is to highlight the classification, treatment and prognosis of acute pancreatitis. Material & Methods : We reviewed the English-language literature (Medline) addressing pancreatitis. Results : Acute pancreatitis is frequently caused by gallstone disease or excess alcohol ingest...

  18. Acute pancreatitis

    Bo-Guang Fan; Åke Andrén-Sandberg

    2010-01-01

    Background: Acute pancreatitis continues to be a serious illness, and the patients with acute pancreatitis are at risk to develop different complications from ongoing pancreatic inflammation. Aims: The present review is to highlight the classification, treatment and prognosis of acute pancreatitis. Material & Methods: We reviewed the English-language literature (Medline) addressing pancreatitis. Results: Acute pancreatitis is frequently caused by gallstone disease or excess alcohol ingestion....

  19. Cadmium - a complex environmental problem. Part II. Cadmium in sludges used as fertilizer

    Davis, R.D.

    1984-02-15

    Utilisation of sewage sludge as a fertilizer is the most economic disposal route for inland sewage-treatment works. Much of the cadmium in wastewater is concentrated into sludge. It is impracticable to reduce cadmium concentrations in sludge below certain levels. Cadmium is a principal factor limiting the use of sludge on land. Investigations are described which have attempted to identify and to determine the availability of forms of cadmium in soil. There is considerable research interest in cadmium in soil solution which is likely to be directly available for crop uptake. Another area of interest is the apparent disappearance of cadmium from sludge-treated soil. Soil analysis often cannot fully account for the cadmium added in sludge. Apart from the effect of soil conditions, especially pH value, crop uptake varies according to the particular crop examined. Highest concentrations of cadmium occur in tobacco, lettuce, spinach and other leafy vegetables. Using crop uptake data from field trials it is possible to relate potential human dietary intake of cadmium, on which hazard depends, to soil concentrations of cadmium, which can be controlled by regulating applications of sludge. This provides an objective basis for limits for cadmium concentrations in soils receiving sludge. Transfer of cadmium via farm animals to meat and dairy products for human consumption is thought to be minimal, even allowing for some direct ingestion of sludge-treated soil by the animals. Evidence from these and other investigations suggests that a loading rate limit of 5 kg Cd/ha (equivalent to a soil concentration of about 3.5 mg Cd/kg) affords adequate protection to the foodchain where sludge is used on agricultural land.

  20. Genotoxic Evaluation of Mexican Welders Occupationally Exposed to Welding-Fumes Using the Micronucleus Test on Exfoliated Oral Mucosa Cells: A Cross-Sectional, Case-Control Study.

    Ana Cecilia Jara-Ettinger

    Full Text Available An estimated 800,000 people worldwide are occupationally exposed to welding-fumes. Previous studies show that the exposure to such fumes is associated with damage to genetic material and increased cancer risk. In this study, we evaluate the genotoxic effect of welding-fumes using the Micronucleus Test on oral mucosa cells of Mexican welders.We conducted a cross-sectional, matched case-control study of n = 66 (33 exposed welders, and 33 healthy controls. Buccal mucosa smears were collected and stained with acridine orange, observed under 100x optical amplification with a fluorescence lamp, and a single-blinded observer counted the number of micronuclei and other nuclear abnormalities per 2,000 observed cells. We compared the frequencies of micronuclei and other nuclear abnormalities, and fitted generalised linear models to investigate the interactions between nuclear abnormalities and the exposure to welding-fumes, while controlling for smoking and age.Binucleated cells and condensed-chromatin cells showed statistically significant differences between cases and controls. The frequency of micronuclei and the rest of nuclear abnormalities (lobed-nuclei, pyknosis, karyolysis, and karyorrhexis did not differ significantly between the groups. After adjusting for smoking, the regression results showed that the occurrence of binucleated cells could be predicted by the exposure to welding-fumes plus the presence of tobacco consumption; for the condensed-chromatin cells, our model showed that the exposure to welding-fumes is the only reliable predictor.Our findings suggest that Mexican welders who are occupationally exposed to welding-fumes have increased counts of binucleated and condensed-chromatin cells. Nevertheless, the frequencies of micronuclei and the rest of nuclear abnormalities did not differ between cases and controls. Further studies should shed more light on this subject.

  1. Effect of iron upon cadmium-manganese and cadmium-iron interaction

    Increase cadmium production has enhanced the potential danger of this toxic metal including its effect upon the metabolism of some essential elements as, for instance, manganese of some essential elements as, for instance, manganese and iron. Relevant data about the cadmium-manganese interaction are rather scanty. Since there are more data of the effect of iron on the metabolism of either of these ions independently. The authors decided to investigate how the presence of iron affected the interaction between cadmium and manganese and how cadmium alone or in combination with the additional iron affected iron transfer and retention in the intestinal wall

  2. Tripolyphosphates of potassium-cadmium and ammonium-cadmium

    Formation of barely soluble compounds during interaction of ammonium and potassium tripolyphosphates with cadmium nitrate in aqueous solutions (0.1-2.0 mol% concentration, the temperature 20 deg C), is investigated. KCd2P3O10x7H2O, NH4Cd2P3O10x7H2O crystallohydrates and Cd5(P3O10)2xhH2O (x=10-13) X-ray amorphous salt, that are dissolved in potassium and ammonium tripolyphosphate solution with formation of Cd2+:P3O105-=1:1 and 1:2 complexes, are separated. In K5P3O10-Cd(NO3)2-H2O system Cd2+:P3O105-=1:1 complex is crystallized in a mixture with varied composition amorphous phase

  3. Acute pulmonary alveolar proteinosis due to exposure to cotton dust

    Thind Gurcharan

    2009-01-01

    Full Text Available Secondary pulmonary alveolar proteinosis (PAP is rare but may occur in association with malignancy, certain infections, and exposure to inorganic or organic dust and some toxic fumes. This case report describes the second recorded case of PAP due to exposure to cotton dust. A 24-year-old man developed PAP after working as a spinner for eight years without respiratory protection. He was admitted as an emergency patient with very severe dyspnea for four months and cough for several years. Chest X-ray showed bilateral diffuse alveolar consolidation. He died 16 days later, and a diagnosis of acute pulmonary alveolar proteinosis was made at autopsy. The histopathology demonstrated alveoli and respiratory bronchioles filled with characteristic periodic acid Schiff-positive material, which also revealed birefringent bodies of cotton dust under polarized light. Secondary PAP can be fatal and present with acute respiratory failure. The occupational history and characteristic pathology can alert clinicians to the diagnosis.

  4. Acute pancreatitis

    Bo-Guang Fan

    2010-05-01

    Full Text Available Background: Acute pancreatitis continues to be a serious illness, and the patients with acute pancreatitis are at risk to develop different complications from ongoing pancreatic inflammation. Aims: The present review is to highlight the classification, treatment and prognosis of acute pancreatitis. Material & Methods: We reviewed the English-language literature (Medline addressing pancreatitis. Results: Acute pancreatitis is frequently caused by gallstone disease or excess alcohol ingestion. There are a number of important issues regarding clinical highlights in the classification, treatment and prognosis of acute pancreatitis, and treatment options for complications of acute pancreatitis including pancreatic pseudocysts. Conclusions: Multidisciplinary approach should be used for the management of the patient with acute pancreatitis.

  5. Acute pancreatitis

    Bo-Guang Fan

    2010-01-01

    Full Text Available Background : Acute pancreatitis continues to be a serious illness, and the patients with acute pancreatitis are at risk to develop different complications from ongoing pancreatic inflammation. Aims : The present review is to highlight the classification, treatment and prognosis of acute pancreatitis. Material & Methods : We reviewed the English-language literature (Medline addressing pancreatitis. Results : Acute pancreatitis is frequently caused by gallstone disease or excess alcohol ingestion. There are a number of important issues regarding clinical highlights in the classification, treatment and prognosis of acute pancreatitis, and treatment options for complications of acute pancreatitis including pancreatic pseudocysts. Conclusions : Multidisciplinary approach should be used for the management of the patient with acute pancreatitis.

  6. Market for nickel-cadmium batteries

    Putois, F.

    Besides the lead/acid battery market, which has seen a tremendous development linked with the car industry, the alkaline rechargeable battery market has also been expanded for more than twenty years, especially in the field of portable applications with nickel-cadmium batteries. Today, nickel-cadmium batteries have to face newcomers on the market, such as nickel-metal hydride, which is another alkaline couple, and rechargeable lithium batteries; these new battery systems have better performances in some areas. This work illustrates the status of the market for nickel-cadmium batteries and their applications. Also, for two major applications—the cordless tool and the electric vehicles—the competitive situation of nickel-cadmium batteries; facing new systems such as nickel-metal hydride and lithium ion cells are discussed.

  7. External costs of cadmium emissions to soil

    Pizzol, Massimo; Smart, James C. R.; Thomsen, Marianne

    2014-01-01

    concentration to be calculated for each scenario. Human exposure was determined based on soil-crop bioconcentration factors for cadmium and dietary intake rates of Danish food crops. Updated dose-response functions linking lifetime cadmium intake to the probability of developing cadmium-induced renal disease...... and osteoporosis were applied. These impacts were converted into monetary values by using the EU standard value of a life-year adjusted for quality of life experience. Annualized cost per unit of phosphorus and cadmium are presented, discounted and undiscounted, for comparison. Application of struvite (magnesium...... ammonium phosphate) and mineral fertilizer produced the lowest external health costs, followed by the fertilizer products wastewater sludge and pig manure. The external cost estimates produced in this study could be used to design economic policy instruments to encourage use of cleaner fertilizer products....

  8. Soybean phytoremediation of cadmium polluted agricultural soils

    Mihajlov, Ljupco; Zajkova-Paneva, Vesna; Balabanova, Biljana

    2015-01-01

    Soil pollution with cadmium is a result of the strengthened industrial development, especially in the areas of drilling, exploitation and processing of mineral raw materials. On the territory of the Republic of Macedonia there are several areas with significant higher content of cadmium in the soil, including the vicinity of the mine lead and zinc “Zletovo” near the town of Probištip. Phytoremediation is one of the most convenient techniques for remediation of heavy metals from conta...

  9. Cadmium poisoning. Knowledge of the risk

    This data sheet provides an up-to-date summary of information on cadmium poisoning. The following points are examined: - the problem of increasing pollution of soil, water and the food chain; - physical and chemical properties, manufacture, industrial applications; - the toxic action of cadmium and its derivatives; - methods and apparatus for taking and analysis samples from the atmosphere and from body fluids; - existing French regulations; - technical control and medical surveillance

  10. Cathodoluminescence of cadmium diphosphide crystals

    An investigation is made of the cathodoluminescence spectra of CdP2 crystals in the temperature range 6 to 300 K. A pulsing beam of high energy electrons (40 kV) is used in the experiment. The samples investigated are undoped, heat annealed in vacuum or saturated vapours of cadmium, and also doped with As and Bi, elements isoelectronic to phosphorus. The experimental results show that the fine structure present in the higher energywing (2.02 to 2.14 eV) depends on the concentration of the uncontrolled nitrogen impurity in CdP2. Atoms of nitrogen give rise to exciton-impurity complexes, leading to intense narrow peaks in the spectrum of cathodoluminescence. Their location and nature are shown in a table. (author)

  11. Cadmium zinc telluride spectral modeling

    Cadmium zinc telluride (CZT) detectors are the highest resolution room temperature gamma-ray detectors available for isotopic analysis. As with germanium detectors, accurate isotopic analysis using spectra requires peak deconvolution. The CZT peak shapes are asymmetric, with a long low energy tail. The asymmetry is a result of the physics of the electron/hole transport in the semiconductor. An accurate model of the physics of the electron/hole transport through an electric field will allow the parameterization of the peak shapes as a function of energy. In turn this leads to the ability to perform accurate spectral deconvolution and therefore accurate isotopic analysis. The model and the peak-shape parameterization as a function of energy will be presented

  12. 油烟气净化技术及发展趋势分析%Brief Discussion on the Oil Fume Purification Technology and Its Development

    郑盼; 张震斌; 纪洪超; 廖翔; 王帅

    2015-01-01

    针对油烟气污染问题,分析了油烟气的组成及其对人体和环境造成的危害,阐述了国内外油烟气污染及治理现状和当下我国对油烟的法律法规,列举了当下常用的油烟净化处理方法,如静电法、吸附法、过滤法、液体洗涤法、惯性分离法、热氧化焚烧法、催化净化法、复合式法以及超重立法等的优缺点,并对油烟净化未来的发展方向做出了展望。%Aiming at the oil fume pollution ,the article expounds the formation of oil fume and its harm to human and environment .Then the article reviews the oil fume pollution aboard and at home ,the present control situation and laws of treating it in China .Several oil fume purification methods have been listed ,such as electrostatic method , adsorption method , filtration method , liquid scrubber , inertia separation , thermal oxidation burning method , catalytic purification method ,hybrid method and ultra - gravity method ,etc .At last ,the article prospects the direction of future development of oil fume purification .

  13. Cadmium leaching from thermal treated and gamma irradiated Mexican aluminosilicates

    Thermal and radiation effects on the leaching of cadmium from two cadmium exchanged zeolitic tuffs and one clay were determined. The cadmium exchanged aluminosilicates were heated at different temperatures (500, 700, 900 and 1100 oC), and the materials were then treated with NaCl (1 M and 5 M) and HNO3 (0.001 M and 1 M) solutions to determine the leaching behaviour of cadmium from the materials. The stability of cadmium in the materials increased as the heating temperature was increased. Cadmium leaching from gamma irradiated and heated materials at 1100 oC was higher than leaching from non-irradiated samples

  14. Cadmium affects retinogenesis during zebrafish embryonic development

    Ocular malformations are commonly observed in embryos of aquatic species after exposure to toxicants. Using zebrafish embryos as the model organism, we showed that cadmium exposure from sphere stage (4 hpf) to end of segmentation stage (24 hpf) induced microphthalmia in cadmium-treated embryos. Embryos with eye defects were then assessed for visual abilities. Cadmium-exposed embryos were behaviorally blind, showing hyperpigmentation and loss of camouflage response to light. We investigated the cellular basis of the formation of the small eyes phenotype and the induction of blindness by studying retina development and retinotectal projections. Retinal progenitors were found in cadmium-treated embryos albeit in smaller numbers. The number of retinal ganglion cells (RGC), the first class of retinal cells to differentiate during retinogenesis, was reduced, while photoreceptor cells, the last batch of retinal neurons to differentiate, were absent. Cadmium also affected the propagation of neurons in neurogenic waves. The neurons remained in the ventronasal area and failed to spread across the retina. Drastically reduced RGC axons and disrupted optic stalk showed that the optic nerves did not extend from the retina beyond the chiasm into the tectum. Our data suggested that impairment in neuronal differentiation of the retina, disruption in RGC axon formation and absence of cone photoreceptors were the causes of microphthalmia and visual impairment in cadmium-treated embryos

  15. Electron paramagnetic resonance study of paramagnetic centers in carbon-fumed silica adsorbent

    Fumed silica A-300 was carbonized by means of pyrolysis of CH2Cl2. The obtained initial SiO2:C nanopowders of black color, with an average diameter of 14–16 nm and carbon (C) concentration 7 wt. %, subjected to the oxidation and passivation treatment were studied by electron paramagnetic resonance (EPR) in the temperature range 4–400 K. Two EPR signals of Lorentzian lineshape with nearly equal g-factors and different linewidth were observed in the initial, oxidized, and passivated SiO2:C nanopowders. The two-component EPR spectrum was explained by the presence of C in two electronic states. The intensive narrow EPR signal, which has a temperature-dependent intensity, linewidth, and resonance field position, was attributed to the carbon-related defect with non-localized electron hopping between neighboring C-dangling bonds. The striking effect is that the temperature dependence of the EPR linewidth demonstrates the motional narrowing of the EPR signal at very low temperatures from 4 K to 20 K, which is not typically for nonmetallic materials and was explained by the quantum character of C layer conductivity in the SiO2:C. The observed peaks in the temperature dependence of the conduction electron EPR signal integral intensity in the high-temperature range 200–440 K was explained by the presence of the C nanodots at the surface of SiO2 nanoparticles and the ejection of electrons from the confinement energy levels of C quantum dot when the temperature becomes comparable to the confinement energy

  16. Effect of silica fume addition on the PGNAA measurement of chlorine in concrete

    Naqvi, A.A. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)], E-mail: aanaqvi@kfupm.edu.sa; Maslehuddin, M. [Center for Engineering Research, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Garwan, M.A. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Nagadi, M.M. [Center for Engineering Research, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Al-Amoudi, O.S.B. [Department of Civil Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Raashid, M.; Khateeb-ur-Rehman [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2010-03-15

    Pozzolanic materials, such as fly ash (FA), silica fume (SF), and blast furnace slag (BFS) are added to Portland cement in concrete to prevent reinforcement steel corrosion in concrete. Further preventive measure against reinforcement steel corrosion require monitoring of chloride salts concentration in concrete using non-destructive techniques, such as the prompt gamma-ray neutron activation analysis (PGNAA) technique. Due to interferences between gamma-rays from chlorine and calcium in PGNAA technique, detection limit of chlorine in concrete strongly depends upon calcium concentration in concrete. SF mainly contains silica and its addition to cement concrete reduces overall concentration of calcium in concrete. This may result in an improvement in detection limit of chlorine in SF-based concrete in PGNAA studies. Particularly for chlorine detection using 6.11 and 6.62 MeV prompt gamma-rays that strongly interfere with 6.42 MeV prompt gamma-rays from calcium. In this study, SF was added to Portland cement to prevent concrete reinforcement steel from corrosion. The chlorine concentration in SF cement concrete specimens containing 0.2-3.0 wt% chlorine was measured through yield of 1.16, 1.95, 6.11, 6.62, 7.41, 7.79, and 8.58 MeV chlorine gamma-rays using PGNAA technique. An excellent agreement was noted between the experimental yield of the prompt gamma-rays and the gamma-ray yield calculated through the Monte Carlo simulations. Further the minimum detectable concentration (MDC) of chlorine in SF cement concrete was calculated and compared with the MDC values of chlorine in plain concrete and concrete mixed with fly ash cement. The MDC of chlorine in SF-based concrete through 6.11 MeV, and 6.62 MeV chlorine gamma-rays was found to be improved as compared to those in plain concrete and concrete mixed with fly ash cement.

  17. Effect of silica fume addition on the PGNAA measurement of chlorine in concrete

    Pozzolanic materials, such as fly ash (FA), silica fume (SF), and blast furnace slag (BFS) are added to Portland cement in concrete to prevent reinforcement steel corrosion in concrete. Further preventive measure against reinforcement steel corrosion require monitoring of chloride salts concentration in concrete using non-destructive techniques, such as the prompt gamma-ray neutron activation analysis (PGNAA) technique. Due to interferences between gamma-rays from chlorine and calcium in PGNAA technique, detection limit of chlorine in concrete strongly depends upon calcium concentration in concrete. SF mainly contains silica and its addition to cement concrete reduces overall concentration of calcium in concrete. This may result in an improvement in detection limit of chlorine in SF-based concrete in PGNAA studies. Particularly for chlorine detection using 6.11 and 6.62 MeV prompt gamma-rays that strongly interfere with 6.42 MeV prompt gamma-rays from calcium. In this study, SF was added to Portland cement to prevent concrete reinforcement steel from corrosion. The chlorine concentration in SF cement concrete specimens containing 0.2-3.0 wt% chlorine was measured through yield of 1.16, 1.95, 6.11, 6.62, 7.41, 7.79, and 8.58 MeV chlorine gamma-rays using PGNAA technique. An excellent agreement was noted between the experimental yield of the prompt gamma-rays and the gamma-ray yield calculated through the Monte Carlo simulations. Further the minimum detectable concentration (MDC) of chlorine in SF cement concrete was calculated and compared with the MDC values of chlorine in plain concrete and concrete mixed with fly ash cement. The MDC of chlorine in SF-based concrete through 6.11 MeV, and 6.62 MeV chlorine gamma-rays was found to be improved as compared to those in plain concrete and concrete mixed with fly ash cement.

  18. Rocket Performance of Red Fuming Nitric Acid with Blends of Norbornadiene, Carene and Cardanol

    R. Chhibber

    1992-07-01

    Full Text Available The fuel blends of nornornadiene and carene (50:50 by weight and norbornadiene, carene and cardanol (40:40:20 by weight exhibit synergistic hypergolic ignition with red fuming nitric acid (RFNA as oxidiser. These fuel blends have been evaluated by theoretical calculations of performance parameters and subsequently verified by static firing in a 10 kg/sub f/ thruster at a chamber pressure of around 20 atm, using RFNA (with 21 per cent N/sub 2/O/sub 4/ by weight as oxidiser. The theoretical calculations show maximum specific impulse and C*values at the O/F, 3 to be 227.8 s and 1598.7 m/s respectively for the norbornadiene-carene blend. The corresponding values for the norbornadiene, carene and cardanol blend were found to be 226.8 s and 1586.0 m/s respectively at the O/F, 4. For theoretical calculations, the chamber pressure (P/sub c and the exit pressure (P/sub e/0 were assumed to be 20 and 1 atm, respectively. The static firing of the propellants in a 10 kg thruster exhibited smooth pressure-time curves with the experimental C* values in close agreement with those calculated and the non-deposition of carbon in the nozzle. This indicated low combustion instability and high combustion efficiency under rocket conditions (> 0.9. The fuel blends with their low cost and toxicity and relatively high density can replace G-fuel used in several Indian missiles without impairing the performance.

  19. Electron paramagnetic resonance study of paramagnetic centers in carbon-fumed silica adsorbent

    Savchenko, D. V., E-mail: dariyasavchenko@gmail.com [Institute of Physics AS CR, Prague 182 21 (Czech Republic); V.E. Lashkaryov Institute of Semiconductor Physics, NASU, Kyiv 03028 (Ukraine); Shanina, B. D.; Kalabukhova, E. N.; Sitnikov, A. A.; Lysenko, V. S. [V.E. Lashkaryov Institute of Semiconductor Physics, NASU, Kyiv 03028 (Ukraine); Tertykh, V. A. [A.A. Chuiko Institute of Surface Chemistry, NASU, Kyiv 03164 (Ukraine)

    2014-04-07

    Fumed silica A-300 was carbonized by means of pyrolysis of CH{sub 2}Cl{sub 2}. The obtained initial SiO{sub 2}:C nanopowders of black color, with an average diameter of 14–16 nm and carbon (C) concentration 7 wt. %, subjected to the oxidation and passivation treatment were studied by electron paramagnetic resonance (EPR) in the temperature range 4–400 K. Two EPR signals of Lorentzian lineshape with nearly equal g-factors and different linewidth were observed in the initial, oxidized, and passivated SiO{sub 2}:C nanopowders. The two-component EPR spectrum was explained by the presence of C in two electronic states. The intensive narrow EPR signal, which has a temperature-dependent intensity, linewidth, and resonance field position, was attributed to the carbon-related defect with non-localized electron hopping between neighboring C-dangling bonds. The striking effect is that the temperature dependence of the EPR linewidth demonstrates the motional narrowing of the EPR signal at very low temperatures from 4 K to 20 K, which is not typically for nonmetallic materials and was explained by the quantum character of C layer conductivity in the SiO{sub 2}:C. The observed peaks in the temperature dependence of the conduction electron EPR signal integral intensity in the high-temperature range 200–440 K was explained by the presence of the C nanodots at the surface of SiO{sub 2} nanoparticles and the ejection of electrons from the confinement energy levels of C quantum dot when the temperature becomes comparable to the confinement energy.

  20. On the mechanism of cadmium toxicity: Suppression of mitochondrial respiration by an organic complex of cadmium

    Korotkov, S.M.; Rozengart, E.V.; Suvorov, A.A.; Nesterov, V.P.; Khovanskikh, A.E. [Setchenow Institute of Evolutionary Physiology and Biochemistry, St. Petersburg (Russian Federation)

    1994-09-01

    Mitochondria are the main targets of the deleterious effect of cadmium. It was found that 94% of cadmium in mitochondria exists as a soluble complex with low-molecular-weight proteins, i.e., metallothioneins. The remaining 6% of cadmium is bound to protein structures of the mitochondrial matrix and, thereby cause the dysfunction of subcellular organelles in vivo. The mechanism of direct interaction of cadmium with the target protein is unknown; however, it is evident that the incorporation of cadmium into a complex with an organic ligand can significantly affect this process and eventually affect the interaction of cadmium with matrix proteins. It was of interest to compare the effects of an inorganic cadmium salt (hydrated Cd{sup 2+} cation) and an organic complex of cadmium [Cd(II)-1,3-bis-(chlorobenzylidenamino)guanidine, CBG] on rat liver mitochondrial respiration. This complex was earlier shown to display a wide range of biological activities. Particularly, it appeared to be more potent than Cd{sup 2+} in inhibiting monoamine oxidase.

  1. Abrasion Properties of Steel Fiber Reinforced Silica Fume Concrete According to Los Angeles and Water Abrasion Tests

    Tsan-Ching CHENG

    2014-12-01

    Full Text Available The current study mainly investigated the influence of different tests on the abrasion resistance of concrete mixed with steel fibers and silica fume. The abrasion resistance was assessed at 28, 56 and 91 days on concretes with water-binder ratios of 0.35 and 0.55 where in some mixes silica fume was substituted by 5 % of cement by weight. Steel fibers of 0.5 % and 1.0 % of concrete volume were also added into the test concrete by replacement of coarse and fine aggregates. The results showed that concrete with higher compressive strength in Los Angeles abrasion tests also had better abrasion resistance. The inclusion of steel fibers into test concrete with a water-binder ratio of 0.35 resulted in a significant increase in compressive strength. This concrete also displayed better abrasion resistance and splitting tensile strength than reference concrete; in the test sample with a water-binder ratio of 0.55, the added steel fibers was unable to effectively produce cementation with the concrete. The inclusion of silica fume improved the abrasion resistance of concretes. In water abrasion testing, the abrasion resistance of concrete containing steel fiber was worse than that of concrete without steel fibers. In the water abrasion testing, the surface of steel fiber reinforced concrete was eroded by water and steel balls, and the impact caused the steel fibers to separate from the concrete and led to higher wear loss. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6460

  2. Cadmium removal by Lemna minor and Spirodela polyrhiza.

    Chaudhuri, Devaleena; Majumder, Arunabha; Misra, Amal K; Bandyopadhyay, Kaushik

    2014-01-01

    The present study investigates the ability of two genus of duckweed (Lemna minor and Spirodela polyrhiza) to phytoremediate cadmium from aqueous solution. Duckweed was exposed to six different cadmium concentrations, such as, 0.5,1.0,1.5, 2.0, 2.5, and 3.0 mg/L and the experiment was continued for 22 days. Water samples were collected periodically for estimation of residual cadmium content in aqueous solution. At the end of treatment period plant samples were collected and accumulated cadmium content was measured. Cadmium toxicity was observed through relative growth factor and changes in chlorophyll content Experimental results showed that Lemna minor and Spirodela polyrhiza were capable of removing 42-78% and 52-75% cadmium from media depending upon initial cadmium concentrations. Cadmium was removed following pseudo second order kinetic model Maximum cadmium accumulation in Lemna minor was 4734.56 mg/kg at 2 mg/L initial cadmium concentration and 7711.00 mg/kg in Spirodela polyrhiza at 3 mg/L initial cadmium concentration at the end of treatment period. Conversely in both cases maximum bioconcentration factor obtained at lowest initial cadmium concentrations, i.e., 0.5 mg/L, were 3295.61 and 4752.00 for Lemna minor and Spirodela polyrhiza respectively. The present study revealed that both Lemna minor and Spirodela polyrhiza was potential cadmium accumulator. PMID:24933906

  3. Effects of cadmium on nickel electrodes in nickel-cadmium cells

    Nickel cadmium battery cells containing nicel electrodes that are not treated with cadmium during the manufacturing process have a history of performance variability and capacity problems in various cell test programs. In this work cadmium additions to the nickel electrode are examined to determine the effects on the fundamental electrochemical processes occurring at this electrode. The results indicate that cadmium treatments improve recharge efficiency by increasing the potential required for oxygen evolution from the nickel electrode, thus decreasing the overcharge rate at a given voltage and allowing the nickel electrode to attain a higher state of charge. The effects of cadmium treatment become particularly important for stable cell operation at temperatures above 10 C, and for capacity maintenance under conditions of long term, low rate trickle charge

  4. Dermal Uptake from Airborne Organics as an Important Route of Human Exposure to E-Waste Combustion Fumes.

    Wu, Chen-Chou; Bao, Lian-Jun; Tao, Shu; Zeng, Eddy Y

    2016-07-01

    Skin absorption of gaseous organic contaminants is an important and relevant mechanism in human exposure to such contaminants, but has not been adequately examined. This article demonstrates that dermal uptake from airborne contaminants could be recognized as a significant exposure route for local residents subjecting to combustion fume from e-waste recycling activities. It is particularly true for organic pollutants which have high dermal penetration rates and large skin-air partition coefficients, such as low molecular weight plasticizers and flame retardants. PMID:26937778

  5. Exposure to rubber fume and rubber process dust in the general rubber goods, tyre manufacturing and retread industries.

    Dost, A A; Redman, D; Cox, G

    2000-08-01

    This study assesses the current patterns and levels of exposure to rubber fume and rubber process dust in the British rubber industry and compares and contrasts the data obtained from the general rubber goods (GRG), retread tire (RT) and new tire (NT) sectors. A total of 179 rubber companies were visited and data were obtained from 52 general rubber goods, 29 retread tire and 7 new tire manufacturers. The survey was conducted using a questionnaire and included a walk-through inspection of the workplace to assess the extent of use of control measures and the nature of work practices being employed. The most recent (predominantly 1995-97) exposure monitoring data for rubber fume and rubber process dust were obtained from these companies; no additional sampling was conducted for the purpose of this study. In addition to the assessment of exposure data, evaluation of occupational hygiene reports for the quality of information and advice was also carried out.A comparison of the median exposures for processes showed that the order of exposure to rubber fume (E, in mg m(-3)) is: E(moulding) (0.40) approximately E(extrusion) (0.33)>E(milling) (0.18) for GRG; E(press) (0. 32)>E(extrusion) (0.19)>E(autoclave) (0.10) for RT; and E(press) (0. 22) approximately E(all other) (0.22) for NT. The order of exposure to rubber fume between sectors was E(GRG) (0.40)>E(RT) (0.32)>E(NT) (0.22). Median exposures to rubber process dust in the GRG was E(weighing) (4.2)>E(mixing) (1.2) approximately E(milling) (0.8) approximately E(extrusion) (0.8) and no significant difference (P=0. 31) between GRG and NT sectors. The findings compare well with the study carried out in the Netherlands [Kromhout et al. (1994), Annals of Occupational Hygiene 38(1), 3-22], and it is suggested that the factors governing the significant differences noted between the three sectors relate principally to the production and task functions and also to the extent of controls employed. Evaluation of occupational

  6. Ribosomal genes as early targets of cadmium-induced toxicity in Chironomus riparius larvae

    Cadmium is a widespread environmental pollutant that causes severe impacts in organisms. Although the effects of cadmium on aquatic insects have been studied in terms of their toxicity and changes in developmental parameters, little is known about its molecular and genetic effects. We have investigated the alterations in the pattern of gene expression provoked by acute exposure to cadmium in Chironomus riparius Mg. (Diptera, Chironomidae), a sentinel organism widely used in aquatic toxicity testing. The early cytotoxic effects were evaluated using immunocytochemistry and specific fluorescent probes in fourth instar larvae after 12 h of 10 mM cadmium treatments; under these conditions no significant effect on larvae mortality was detected until after 36 h of exposure. The changes in the pattern of gene expression were analysed by means of DNA/RNA hybrid antibodies in the polytene chromosomes from salivary gland cells. A decrease in the activity of the nucleolus is especially remarkable, accompanied by a significant reduction in size and the modification in nucleolar architecture, as shown by FISH. The inhibition of rDNA transcription was further evaluated by Northern blot analysis, which showed a marked decrease in the level of preribosomal rRNA (54% 45S 12 h). However, the BR genes, whose products are the giant polypeptides that constitute the silk-like secretion for constructing housing tubes, remain active. Simultaneously, decondensation and activation take place at some chromosomal regions, especially at the centromeres. The changes observed in the pattern of gene expression do not resemble those found after heat shock or other cell stressors. These data provide the first evidence that cadmium interacts with ribosomal genes and results in a drastic impairment of the functional activity of the nucleolus, an essential organelle for cellular survival. Therefore, the depletion of ribosomes would be a long-term effect of Cd-induced cellular damage. These findings may

  7. Ribosomal genes as early targets of cadmium-induced toxicity in Chironomus riparius larvae

    Planello, R. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain); Martinez-Guitarte, J.L. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain); Morcillo, G. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain)]. E-mail: gmorcillo@ccia.uned.es

    2007-02-01

    Cadmium is a widespread environmental pollutant that causes severe impacts in organisms. Although the effects of cadmium on aquatic insects have been studied in terms of their toxicity and changes in developmental parameters, little is known about its molecular and genetic effects. We have investigated the alterations in the pattern of gene expression provoked by acute exposure to cadmium in Chironomus riparius Mg. (Diptera, Chironomidae), a sentinel organism widely used in aquatic toxicity testing. The early cytotoxic effects were evaluated using immunocytochemistry and specific fluorescent probes in fourth instar larvae after 12 h of 10 mM cadmium treatments; under these conditions no significant effect on larvae mortality was detected until after 36 h of exposure. The changes in the pattern of gene expression were analysed by means of DNA/RNA hybrid antibodies in the polytene chromosomes from salivary gland cells. A decrease in the activity of the nucleolus is especially remarkable, accompanied by a significant reduction in size and the modification in nucleolar architecture, as shown by FISH. The inhibition of rDNA transcription was further evaluated by Northern blot analysis, which showed a marked decrease in the level of preribosomal rRNA (54% 45S 12 h). However, the BR genes, whose products are the giant polypeptides that constitute the silk-like secretion for constructing housing tubes, remain active. Simultaneously, decondensation and activation take place at some chromosomal regions, especially at the centromeres. The changes observed in the pattern of gene expression do not resemble those found after heat shock or other cell stressors. These data provide the first evidence that cadmium interacts with ribosomal genes and results in a drastic impairment of the functional activity of the nucleolus, an essential organelle for cellular survival. Therefore, the depletion of ribosomes would be a long-term effect of Cd-induced cellular damage. These findings may

  8. Cadmium exposure induces hematuria in Korean adults

    Introduction: Toxic heavy metals have adverse effects on human health. However, the risk of hematuria caused by heavy metal exposure has not been evaluated. Methods: Data from 4701 Korean adults were obtained in the Korean National Health and Nutritional Examination Survey (2008–2010). Blood levels of the toxic heavy metals cadmium, lead, and mercury were measured. Hematuria was defined as a result of ≥+1 on a urine dipstick test. The odds ratios (ORs) for hematuria were measured according to the blood heavy metal levels after adjusting for multiple variables. Results: Individuals with blood cadmium levels in the 3rd and 4th quartiles had a greater OR for hematuria than those in the 1st quartile group: 3rd quartile, 1.35 (1.019–1.777; P=0.037); 4th quartile, 1.52 (1.140–2.017; P=0.004). When blood cadmium was considered as a log-transformed continuous variable, the correlation between blood cadmium and hematuria was significant: OR, 1.97 (1.224–3.160; Ptrend=0.005). In contrast, no significant correlations between hematuria and blood lead or mercury were found in the multivariate analyses. Discussion: The present study shows that high cadmium exposure is associated with a risk of hematuria. -- Highlights: • A high level of blood cadmium is associated with a high risk of hematuria. • This correlation is independent of several confounding factors. • Blood levels of lead and mercury are not associated with risk of hematuria. • This is the first study on the correlation between cadmium exposure and hematuria risk

  9. Cadmium exposure induces hematuria in Korean adults

    Han, Seung Seok [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Kim, Myounghee, E-mail: dkkim73@gmail.com [Department of Dental Hygiene, College of Health Science, Eulji University, Gyeonggi-do 461-713 (Korea, Republic of); Lee, Su Mi [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Lee, Jung Pyo [Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul 156-707 (Korea, Republic of); Kim, Sejoong [Department of Internal Medicine, Seoul National University Bundang Hospital, Gyeonggi-do 463-707 (Korea, Republic of); Joo, Kwon Wook [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Lim, Chun Soo [Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul 156-707 (Korea, Republic of); Kim, Yon Su; Kim, Dong Ki [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of)

    2013-07-15

    Introduction: Toxic heavy metals have adverse effects on human health. However, the risk of hematuria caused by heavy metal exposure has not been evaluated. Methods: Data from 4701 Korean adults were obtained in the Korean National Health and Nutritional Examination Survey (2008–2010). Blood levels of the toxic heavy metals cadmium, lead, and mercury were measured. Hematuria was defined as a result of ≥+1 on a urine dipstick test. The odds ratios (ORs) for hematuria were measured according to the blood heavy metal levels after adjusting for multiple variables. Results: Individuals with blood cadmium levels in the 3rd and 4th quartiles had a greater OR for hematuria than those in the 1st quartile group: 3rd quartile, 1.35 (1.019–1.777; P=0.037); 4th quartile, 1.52 (1.140–2.017; P=0.004). When blood cadmium was considered as a log-transformed continuous variable, the correlation between blood cadmium and hematuria was significant: OR, 1.97 (1.224–3.160; P{sub trend}=0.005). In contrast, no significant correlations between hematuria and blood lead or mercury were found in the multivariate analyses. Discussion: The present study shows that high cadmium exposure is associated with a risk of hematuria. -- Highlights: • A high level of blood cadmium is associated with a high risk of hematuria. • This correlation is independent of several confounding factors. • Blood levels of lead and mercury are not associated with risk of hematuria. • This is the first study on the correlation between cadmium exposure and hematuria risk.

  10. Copper-cadmium interaction in mice: effects of copper status on retention and distribution of cadmium after cadmium exposure

    The role of increased dietary copper in altering the accumulation of cadmium and other metals in tissues, was investigated. Female Swiss-Webster mice were pretreated with cadmium or copper in drinking water for three weeks prior to cadmium exposure for an additional nine weeks, with sub groups from each dose level receiving Cu additions to the Cd supplemented water. In Cd pretreated animals, a significant decrease was observed in Cd concentrations in liver and kidney when Cu was added to Cd in drinking water. Cadmium levels in soluble protein fractions of liver of animals administered 5 ppm Cd were approximately three fold greater than that for the same Cd dose when Cu was added. The same was the case for the metallothionein-like protein fraction (MTP) of the liver cytosol. In copper pretreated animals similar trends were noted in that brain, spleen, liver (but not kidney) Cd levels were decreased in animals receiving Cu additions to the Cd dose. Increased binding of Cd to the MTP fraction was observed after both in vivo and in vitro exposure of intestinal mucosal cells to cadmium

  11. On the effect of thallium additions on cadmium amalgam potentials

    A study has been made of the influence of additives of thallium on potentials of cadmium amalgams with thallium contents of 10, 20, 30, and 40 at.% at 20, 40, 60, and 80 deg C. Additives of thallium have been found to shift the potential of cadmium amalgams towards the range of negative values which indicates an increase in the activity of cadmium. A possibility of calculation of the potential shift for heterogeneous cadmium amalgams on introducing thallium has been shown

  12. Effect of silica fume addition on the PGNAA measurement of chlorine in concrete.

    Naqvi, A A; Maslehuddin, M; Garwan, M A; Nagadi, M M; Al-Amoudi, O S B; Raashid, M; Khateeb-ur-Rehman

    2010-03-01

    Pozzolanic materials, such as fly ash (FA), silica fume (SF), and blast furnace slag (BFS) are added to Portland cement in concrete to prevent reinforcement steel corrosion in concrete. Further preventive measure against reinforcement steel corrosion require monitoring of chloride salts concentration in concrete using non-destructive techniques, such as the prompt gamma-ray neutron activation analysis (PGNAA) technique. Due to interferences between gamma-rays from chlorine and calcium in PGNAA technique, detection limit of chlorine in concrete strongly depends upon calcium concentration in concrete. SF mainly contains silica and its addition to cement concrete reduces overall concentration of calcium in concrete. This may result in an improvement in detection limit of chlorine in SF-based concrete in PGNAA studies. Particularly for chlorine detection using 6.11 and 6.62 MeV prompt gamma-rays that strongly interfere with 6.42 MeV prompt gamma-rays from calcium. In this study, SF was added to Portland cement to prevent concrete reinforcement steel from corrosion. The chlorine concentration in SF cement concrete specimens containing 0.2-3.0 wt% chlorine was measured through yield of 1.16, 1.95, 6.11, 6.62, 7.41, 7.79, and 8.58 MeV chlorine gamma-rays using PGNAA technique. An excellent agreement was noted between the experimental yield of the prompt gamma-rays and the gamma-ray yield calculated through the Monte Carlo simulations. Further the minimum detectable concentration (MDC) of chlorine in SF cement concrete was calculated and compared with the MDC values of chlorine in plain concrete and concrete mixed with fly ash cement. The MDC of chlorine in SF-based concrete through 6.11 MeV, and 6.62 MeV chlorine gamma-rays was found to be improved as compared to those in plain concrete and concrete mixed with fly ash cement. PMID:20042342

  13. Peak expiratory flow rate in asymptomatic male workers exposed to chemical fumes, in various industries of Hyderabad

    Padaki Samata K, Dambal Amrut , Kokiwar Prashant

    2014-11-01

    Full Text Available Context: The prevalence of occupational health hazards and mortality has been reported to be unusually high among people of India. Although developed countries are very much careful about the health in occupations it is quite neglected in the developing countries like India. Aims: To record PEFR in asymptomatic male workers exposed to chemical fumes for more than 2 years and compare the results with age matched unexposed, healthy male controls. Methods and Material: This was a comparative study between 50 asymptomatic male workers exposed to chemical fumes for more than 2 years in various industries located at Jeedimetla Industrial Area and 50 unexposed healthy male individuals from general population. The sampling was done by simple random sampling (lottery method. The data was collected in the Research Laboratory of Physiology. Anthropometry like weight, height, was measured and the PEFR test was performed in the standing position by taking a deep inspiration and then blowing out as hard and as quickly as possible with their nose closed. Data was analyzed by using SPSS package and was expressed in terms of mean ± SD. Results: It was observed that mean PEFR was statistically highly significant in cases (p = 0.0001, and PEFR decreased with increase in duration of exposure. Conclusions: Thus, it can be concluded that apparently healthy individuals may also have abnormal PEFR findings. Hence, a regular check on these parameters will help them in reducing the chances of its manifestation at a future date.

  14. Effect of magnesium and sulfate ions on durability of silica fume blended mixes exposed to the seawater tidal zone

    The effect of silica fume on deterioration resistance to sulfate attack in seawater within tidal zone and simulated wetting-drying condition has been studied in Portland cement concretes and pastes containing silica fume (SF) with/without ground granulated blast furnace slag (GGBS). Changes in the compressive strength and capillary water absorption of specimens as a function of SF content have been investigated combined with phases determination by means of scanning electron microscopy and X-ray energy dispersion analysis. The strength change factors (SCFs) of specimens with SF (the more SF content, the higher strength loss) were greater than that of the mixes without SF or cured under tap water. Mg2+ ion originated attack found to be the dominating deterioration mechanism as confirmed by X-ray and chemical analyses. Further, the incorporation of GGBS with SF mixes in different exposure conditions led to the worst performance in all of the test environments. Lower cement content and hydration rate accompanied with particular chemical composition of GGBS made concrete and paste specimens to be more susceptible to deleterious seawater environment

  15. Probing the hydration of composite cement pastes containing fly ash and silica fume by proton NMR spin-lattice relaxation

    2010-01-01

    Proton NMR spin-lattice relaxation (T1) was used as a prober for observing the hydration process of composite cement pastes blending fly ash and silica fume during the early age.The distribution at initial time,evolution curves and signals intensity of T1 were shown in this paper.Results demonstrate that the T1 distribution curves at initial time exhibit two peaks,which are regarded as two different water phases in the pastes.The evolution curves of T1 are in good agreement with the hydration process of composite pastes and could be roughly divided into four stages:initial period,dormant period,acceleration period and steady period.The hydration mechanism for each stage was discussed.The hydration of the composite cement pastes was retarded by the addition of fly ash and silica fume when compared to that of pure cement.However,the hydration degree of the cement in the blends was promoted.

  16. Effect of anions on Toxicity of Cadmium Applied to MIcrobial Biomass in Red Soil

    K.S.KHAN; XIEZHENGMIAO; 等

    1997-01-01

    A laboratory incubation experiment was conducted to elucidat the effects of associated anions on toxicity of cadmium applied to microbial biomass in the red soil. Cadmium was applied at six different levels,i.e.,O(background),5,15,30,60 and 100μg g-1 soil in the form of either cadmium acetate or cadmium chloride. Application of cadmium as cadmium acetate markedly reduced the soil microbial biomass carbon compared to cadmium applied as cadmium chlorde at all the tested levels.Similarly,organic carbon to biomass carbon ration in the soil was markedly increased by increasing the level of the cadmium in the soil as cadmium acetate,while the change wa much smaller in the case of cadmium chloride at the same cadmium levels.The results suggested that due consideration should be given to the source of cadmium while deciding the cadmium levles in experiments.

  17. Cadmium-113m as a biogeochemical tracer for cadmium in Lake Michigan

    The Lake Michigan watershed has been sampled for 113mCd. This long-lived metastable isotope of cadmium allowed independent evaluation of cadmium distribution in this dynamic ecosystem. 113mCd analysis was not hampered by contamination or loss. These are problems which have plagued stable cadmium measurements. Sensitivity and specificity were necessary concerns. 113mCd has been preconcentrated from large samples in order to obtain sufficient activity for quantification. Specificity for the gross beta activity measured was secured in a rigorous ion exchange decontamination. Confirmation of the suspected 113mCd beta source was checked by reverse tracer analysis and modified Feather analysis range-energy relationships. The 113mCd activities confirm the expected semiconservative behavior for cadmium. This behavior manifests itself in a long residence time for cadmium in Lake Michigan. The inefficiency of outflow removal, the low sedimentation rate and the unquantified sediment resuspension and release of cadmium are factors contributing to this residence time. Steady state concentration of cadmium in Lake Michigan will increase if present input rates persist

  18. Acute toxicity of copper and cadmium for piauçu, Leporinus macrocephalus, and curimatã, Prochilodus vimboides = Toxicidade aguda do cobre e do cádmio no piauçu, Leporinus macrocephalus, e no curimatã, Prochilodus vimboides

    Levy Carvalho Gomes

    2009-07-01

    Full Text Available Ninety-six-hour static bioassays were conducted in the laboratory to determine lethal concentrations (96-h LC50 of copper and cadmium for curimatã (Prochilodus vimboides and piauçu (Leporinus macrocephalus. The 96-h LC50 of copper were 0.047 and 0.090 mg L-1, and of cadmium 3.16 and 7.42 mg L-1 for curimatã and piauçu, respectively. Curimatã is a preferred indigenous species for toxicological studies in the Doce River basin due to its availability in the hatcheries of the region and high sensitivity to metals.Bioensaios estáticos foram realizados em laboratório para determinar a concentração letal (96-h CL50 do cobre e do cádmio para o curimatã (Prochilodus vimboides e o piauçu (Leporinus macrocephalus. A CL50 do cobre é de 0,047 e 0,090 mg L-1 e do cádmio de 3,16 e 7,42 mg L-1 para curimatã e piauçu, respectivamente. O curimatã é a espécie nativa mais adequada para estudos toxicológicos da bacia do rio Doce, por sua fácil disponibilidade em pisciculturas da região e altasensibilidade aos metais.

  19. CONTROL OF CADMIUM CARBONATE PRECIPITATION INTERFERENCES DURING THE DIALYSIS OF CADMIUM IN HIGH BICARBONATE ALKALINITY AQUATIC-LIFE BIOASSAY WATERS

    The precipitation of cadmium carbonate during the dialysis of cadmium in a high bicarbonate alkalinity natural water, was linked to a significant source of error when determining dialyzate cadmium concentrations. The relative standard deviation was reduced by approximately four-f...

  20. Cadmium accumulation by Axonopus compressus (Sw. P. Beauv and Cyperus rotundas Linn growing in cadmium solution and cadmium-zinc contaminated soil

    Paitip Thiravetyan

    2007-05-01

    Full Text Available This research investigated the phyto-remediation potentials of Cyperus rotundas Linn (Nutgrass and Axonopus compressus (Sw. P. Beauv (Carpetgrass for cadmium removal from cadmium solution andcadmium-zinc contaminated soil. Plants growth in the solution showed that cadmium decreased the relative growth rate of both grasses. However, the amount of cadmium accumulated in shoot and root was increasedwith the increase in cadmium concentration and exposure time. Growth in fertile soil mixed with Cd-contaminated zinc silicate residue (65% Si, 19% Ca, 2% Zn, 1% Mg and 0.03% Cd at the ratio of 50:50 (w/wfor 30 days showed that C. rotundas Linn accumulated cadmium in root and shoot to 2,178 and 1,144 mg kg-1 dry weight, respectively. A. compressus (Sw. P. Beauv accumulated cadmium in root and shoot to 1,965and 669 mg kg-1 dry weight, respectively. Scanning electron microscope connected to energy-dispersive X-ray spectroscopy suggested that the mechanism of cadmium accumulation by both grasses involved thecadmium precipitation in the stable form of cadmium silicate, which indicated that C. rotundas Linn and A. compressus (Sw. P. Beauv could be grown to prevent soil erosion and to remediate cadmium-contaminatedsoil.

  1. ELECTROKINETIC REMEDIATION STUDY FOR CADMIUM CONTAMINATED SOIL

    P. Bala Ramudu

    2007-09-01

    Full Text Available This paper presents the results of an experimental research undertaken to evaluate different purging solutions to enhance the removal of cadmium from spiked contaminated field soil by electrokinetic remediation. Three experiments were conducted when soil was saturated with deionised water and subsequently deionised water, ammonium citrate and sodium citrate were used as purging solutions at anode end. One experiment was conducted when the soil was saturated with ammonium citrate and itself was used as the purging solution. Results showed that 49% reduction of cadmium concentration was achieved in the case of soil saturated (washed with ammonium citrate as well as purging solution also was ammonium citrate. The soil pH and washing solutions were the most important factors in controlling the removal of cadmium in electrokinetic remediation process.

  2. Bireactor Electronuclear Systems with Liquid Cadmium Valve

    Bznuni, S A; Zhamkochyan, V M; ASosnin, A N; Polanski, A; Khudaverdyan, A H

    2002-01-01

    Three main types of bireactor electronuclear systems are discussed. From the point of view of assuring high level of functional characteristics and safety bireactor electronuclear systems with booster using enriched uranium (20 %) and with a liquid cadmium valve appears to be the most effective. It is shown by means of Monte-Carlo modeling that such operation conditions can be achieved which lead to the destruction of the intermediate cadmium layer making the systems supercritical (k_{eff}>1). One can avoid the problem by using a special design of the liquid cadmium valve. In comparison with other nuclear systems (critical reactors, one-reactor electronuclear systems) cascade electronuclear systems have essential advantages allowing the decrease of the proton beam current by one order of magnitude and providing at same time the necessary level of power generation and neutron flux. Availability of both the thermal and fast cones allows one to transmute not only transuranics but also the fission products - cesi...

  3. Cadmium tungstate ceramics for application as scintillator

    The aim of the present work is the production of cadmium tungstate scintillator ceramics (CdWO4 - CWO). The route of production employed was the solid state synthesis. Before the calcination, the precursors cadmium oxide and tungsten oxide were homogenized in an agate mortar. Bismuth oxide was used in the production of doped ceramics with 1% in mol of bismuth, in order to improve de efficiency of the scintillators. Since there is a possibility of Cd2+ loss at temperatures above 1000 deg C, ceramics with 1% of cadmium oxide excess were also produced. The crystalline phase was obtained after two calcination, according to X-Ray diffraction results. For the characterization, radioluminescence measurements were performed under β and X-radiation. Images of the surface of the sintered ceramic were registered by Atomic Force Microscopy. The density of ceramics bodies was calculated by the Archimedes' method and compared with the theoretical density (7.99 g/cm3). (author)

  4. Increased cadmium and lead uptake of a cadmium hyperaccumulator tomato by cadmium-resistant bacteria.

    He, Lin-Yan; Chen, Zhao-Jin; Ren, Gai-Di; Zhang, Yan-Feng; Qian, Meng; Sheng, Xia-Fang

    2009-07-01

    Two cadmium (Cd)-resistant strains Pseudomonas sp. RJ10 and Bacillus sp. RJ16 were investigated for their effects on the soil Cd and lead (Pb) solubilization and promotion of plant growth and Cd and Pb uptakes of a Cd-hyperaccumulator tomato. In the heavy metal-contaminated inoculated soil, the CaCl(2)-extractable Cd and Pb were increased by 58-104% and 67-93%, respectively, compared to the uninoculation control. The bacteria produced indole acetic acid, siderophore and 1-aminocyclopropane-1-carboxylate deaminase. Root elongation assay conducted on tomato under gnotobiotic conditions demonstrated increase in root elongation of inoculated tomato seedlings compared to the control plants. An increase in Cd and Pb contents of above-ground tissues varied from 92% to 113% and from 73% to 79% in inoculated plants growing in heavy metal-contaminated soil compared to the uninoculation control, respectively. These results show that the bacteria could be exploited for bacteria enhanced-phytoextraction of Cd- and Pb-polluted soils. PMID:19368973

  5. Treatment of cadmium dust with two-stage leaching process

    2000-01-01

    The treatment of cadmium dust with a two-stage leaching process was investigated to replace the existing sulphation roast-leaching processes. The process parameters in the first stage leaching were basically similar to the neutralleaching in zinc hydrometallurgy. The effects of process parameters in the second stage leaching on the extraction of zincand cadmium were mainly studied. The experimental results indicated that zinc and cadmium could be efficiently recoveredfrom the cadmium dust by two-stage leaching process. The extraction percentages of zinc and cadmium in two stage leach-ing reached 95% and 88% respectively under the optimum conditions. The total extraction percentage of Zn and Cdreached 94%.

  6. Thermodynamic properties of cadmium in lead amalgam dilute solution

    Investigation of thermodynamic properties of cadmium dilute solutions in lead amalgam is carried out by means of electromotive force technique within 453-523 K temperature range. Cadmium thermodynamic functions are calculated: activity, activity ratio, Libbs partial energy and its excess value and integral characteristics, respectively. When changing cadmium content from 0.01 up to 0.1 χcd at T=473 K, logarithm of activity ratio does not depend on alloy composition, that is, Heury's law is fulfilled. Increase of cadmium content in amalgam results in the essential reduction of mercury and cadmium reaction

  7. Urinary excretion of cadmium and zinc among persons from Sweden

    Elinder, C.G.; Kjellstrom, T.; Linnman, L.; Pershagen, G.

    1978-06-01

    Cadmium and zinc concentrations in the urine of 132 Swedes, including 50 pairs of identical twins, were measured. Atomic absorption spectrophotometry procedures were developed for the analysis. Cadmium concentration increased with age and was higher among smokers than among nonsmokers. Estimated 24-hr excretion of cadmium among nonsmokers increased from about 0.25 to 0.40 ..mu..g in persons from 20 to 70 years old. The 24-hr cadmium excretions among nonsmokers in different age-groups fitted better to total kidney burden than to daily cadmium intake from food. Zinc excretion, on the other hand, decreased after the age of 20.

  8. Cadmium telluride quantum dots advances and applications

    Donegan, John

    2013-01-01

    Optical Properties of Bulk and Nanocrystalline Cadmium Telluride, Núñez Fernández and M.I. VasilevskiyAqueous Synthesis of Colloidal CdTe Nanocrystals, V. Lesnyak, N. Gaponik, and A. EychmüllerAssemblies of Thiol-Capped CdTe Nanocrystals, N. GaponikFörster Resonant Energy Transfer in CdTe Nanocrystal Quantum Dot Structures, M. Lunz and A.L. BradleyEmission of CdTe Nanocrystals Coupled to Microcavities, Y.P. Rakovich and J.F. DoneganBiological Applications of Cadmium Telluride Semiconductor Quantum Dots, A. Le Cign

  9. Serum asparate aminotransferase levels following cadmium and/or 60Co radiation

    A total of 216 young adult male Sprague‐Dawley rats were used. Animals were injected intraperitoneally (IP) every 3 days for 29 days for a total of 9 injections with 0, 1.0, or 2.5 mg Cd/kg body wt. Twenty‐four hrs after the last Cd injection (day 30), each animal was subjected to an acute sublethal total‐body exposure of 0, 3.62 or 5.43 gray of gamma (60Co) radiation at a dose rate of 3.04 gray/min. Eight rats from each of the 9 groups were sacrificed by cardiac exsanguination on post‐irradiation day 1, 7, or 21. A significant high‐dose cadmium‐induced increase in AST enzyme was observed at days 1 and 7; however, by day 21 levels had returned to normal. The results suggest that high‐dose cadmium increases were dose and time‐dependent. No significant differences in AST values were observed between radiation only groups, days, or doses. However, significant dose‐related differences were observed between high‐dose cadmium and means, as well as between high and low‐dose cadmium doses at days 1, 7, and 21. When the co‐insult was used, significant differences were seen between the high cadmium‐high radiation group and the mean at day one

  10. Fumed Silica Nanoparticles Incorporated in Quaternized Poly(Vinyl Alcohol Nanocomposite Membrane for Enhanced Power Densities in Direct Alcohol Alkaline Fuel Cells

    Selvaraj Rajesh Kumar

    2015-12-01

    Full Text Available A nanocomposite polymer membrane based on quaternized poly(vinyl alcohol/fumed silica (QPVA/FS was prepared via a quaternization process and solution casting method. The physico-chemical properties of the QPVA/FS membrane were investigated. Its high ionic conductivity was found to depend greatly on the concentration of fumed silica in the QPVA matrix. A maximum conductivity of 3.50 × 10−2 S/cm was obtained for QPVA/5%FS at 60 °C when it was doped with 6 M KOH. The permeabilities of methanol and ethanol were reduced with increasing fumed silica content. Cell voltage and peak power density were analyzed as functions of fumed silica concentration, temperature, methanol and ethanol concentrations. A maximum power density of 96.8 mW/cm2 was achieved with QPVA/5%FS electrolyte using 2 M methanol + 6 M KOH as fuel at 80 °C. A peak power density of 79 mW/cm2 was obtained using the QPVA/5%FS electrolyte with 3 M ethanol + 5 M KOH as fuel. The resulting peak power densities are higher than the majority of published reports. The results confirm that QPVA/FS exhibits promise as a future polymeric electrolyte for use in direct alkaline alcoholic fuel cells.

  11. Cadmium exposure and pancreatic cancer in south Louisiana.

    Luckett, Brian G; Su, L Joseph; Rood, Jennifer C; Fontham, Elizabeth T H

    2012-01-01

    Cadmium has been hypothesized to be a pancreatic carcinogen. We test the hypothesis that cadmium exposure is a risk factor for pancreatic cancer with a population-based case-control study sampled from a population with persistently high rates of pancreatic cancer (south Louisiana). We tested potential dietary and nondietary sources of cadmium for their association with urinary cadmium concentrations which reflect long-term exposure to cadmium due to the accumulation of cadmium in the kidney cortex. Increasing urinary cadmium concentrations were significantly associated with an increasing risk of pancreatic cancer (2nd quartile OR = 3.34, 3rd = 5.58, 4th = 7.70; test for trend P ≤ 0.0001). Potential sources of cadmium exposure, as documented in the scientific literature, found to be statistically significantly associated with increased risk of pancreatic cancer included working as a plumber, pipefitter or welder (OR = 5.88) and high consumption levels of red meat (4th quartile OR = 6.18) and grains (4th quartile OR = 3.38). Current cigarette smoking, at least 80 pack years of smoking, occupational exposure to cadmium and paints, working in a shipyard, and high consumption of grains were found to be statistically significantly associated with increased concentrations of urinary cadmium. This study provides epidemiologic evidence that cadmium is a potential human pancreatic carcinogen. PMID:23319964

  12. Cadmium Exposure and Pancreatic Cancer in South Louisiana

    Brian G. Luckett

    2012-01-01

    Full Text Available Cadmium has been hypothesized to be a pancreatic carcinogen. We test the hypothesis that cadmium exposure is a risk factor for pancreatic cancer with a population-based case-control study sampled from a population with persistently high rates of pancreatic cancer (south Louisiana. We tested potential dietary and nondietary sources of cadmium for their association with urinary cadmium concentrations which reflect long-term exposure to cadmium due to the accumulation of cadmium in the kidney cortex. Increasing urinary cadmium concentrations were significantly associated with an increasing risk of pancreatic cancer (2nd quartile OR = 3.34, 3rd = 5.58, 4th = 7.70; test for trend P≤0.0001. Potential sources of cadmium exposure, as documented in the scientific literature, found to be statistically significantly associated with increased risk of pancreatic cancer included working as a plumber, pipefitter or welder (OR = 5.88 and high consumption levels of red meat (4th quartile OR = 6.18 and grains (4th quartile OR = 3.38. Current cigarette smoking, at least 80 pack years of smoking, occupational exposure to cadmium and paints, working in a shipyard, and high consumption of grains were found to be statistically significantly associated with increased concentrations of urinary cadmium. This study provides epidemiologic evidence that cadmium is a potential human pancreatic carcinogen.

  13. Acute pancreatitis

    ... page: //medlineplus.gov/ency/article/000287.htm Acute pancreatitis To use the sharing features on this page, ... fatty foods after the attack has improved. Outlook (Prognosis) Most cases go away in a week. However, ...

  14. Acute Pericarditis

    ... Sugar Control Helps Fight Diabetic Eye Disease Are 'Workaholics' Prone to OCD, Anxiety? ALL NEWS > Resources First ... cancer, or heart surgery, the fluid is blood. Causes Acute pericarditis usually results from infection or other ...

  15. Simultaneous speciation analysis of chromate, molybdate, tungstate and vanadate in welding fume alkaline extracts by HPLC-ICP-MS.

    Ščančar, Janez; Berlinger, Balázs; Thomassen, Yngvar; Milačič, Radmila

    2015-09-01

    A novel analytical procedure was developed for the simultaneous speciation analysis of chromate, molybdate, tungstate and vanadate by anion-exchange high performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry (HPLC-ICP-MS). Linear gradient elution from 100% water to 100% 0.7 M NaCl was applied for chromatographic separation of metal species. In standard aqueous solution at neutral pH molybdate, tungstate and vanadate exist in several aqueous species, while chromate is present as a single CrO4(2-) species. Consequently, only chromate can be separated from this solution in a sharp chromatographic peak. For obtaining sharp chromatographic peaks for molybdate, tungstate and vanadate, the pH of aqueous standard solutions was raised to 12. At highly alkaline conditions single CrO4(2-), MoO4(2-) and WO4(2-) are present and were eluted in sharp chromatographic peaks, while VO4(3-) species, which predominates at pH 12 was eluted in slightly broaden peak. In a mixture of aqueous standard solutions (pH 12) chromate, molybdate, tungstate and vanadate were eluted at retention times from 380 to 420 s, 320 to 370 s, 300 to 350 s and 240 to 360 s, respectively. Eluted species were simultaneously detected on-line by ICP-MS recording m/z 52, 95, 182 and 51. The developed procedure was successfully applied to the analysis of leachable concentrations of chromate, molybdate, tungstate and vanadate in alkaline extracts (2% NaOH+3% Na2CO3) of manual metal arc (MMA) welding fumes loaded on filters. Good repeatability and reproducibility of measurement (RSD±3.0%) for the investigated species were obtained in both aqueous standard solutions (pH 12) and in alkaline extracts of welding fumes. Low limits of detection (LODs) were found for chromate (0.02 ng Cr mL(-1)), molybdate (0.1 ng Mo mL(-1)), tungstate (0.1 ng W mL(-1)) and vanadate (0.2 ng V mL(-1)). The accuracy of analytical procedure for the determination of chromate was checked by analysis of

  16. Computational Fluid Dynamics (CFD) Investigation of Submerged Combustion Behavior in a Tuyere Blown Slag-fuming Furnace

    Huda, Nazmul; Naser, Jamal; Brooks, G. A.; Reuter, M. A.; Matusewicz, R. W.

    2012-10-01

    A thin-slice computational fluid dynamics (CFD) model of a conventional tuyere blown slag-fuming furnace has been developed in Eulerian multiphase flow approach by employing a three-dimensional (3-D) hybrid unstructured orthographic grid system. The model considers a thin slice of the conventional tuyere blown slag-fuming furnace to investigate details of fluid flow, submerged coal combustion dynamics, coal use behavior, jet penetration behavior, bath interaction conditions, and generation of turbulence in the bath. The model was developed by coupling the CFD with the kinetics equations developed by Richards et al. for a zinc-fuming furnace. The model integrates submerged coal combustion at the tuyere tip and chemical reactions with the heat, mass, and momentum interfacial interaction between the phases present in the system. A commercial CFD package AVL Fire 2009.2 (AVL, Graz, Austria) coupled with several user-defined subroutines in FORTRAN programming language were used to develop the model. The model predicted the velocity, temperature field of the molten slag bath, generated turbulence and vortex, and coal use behavior from the slag bath. The tuyere jet penetration length ( l P) was compared with the equation provided by Hoefele and Brimacombe from isothermal experimental work ( {{l_{{P}} }/{d_{o }} = 10.7( {N^' }_{Fr} } )^{0.46} ( {ρ_{{g}} /ρl } )^{0.35} } ) and found 2.26 times higher, which can be attributed to coal combustion and gas expansion at a high temperature. The jet expansion angle measured for the slag system studied is 85 deg for the specific inlet conditions during the simulation time studied. The highest coal penetration distance was found to be l/L = 0.2, where l is the distance from the tuyere tip along the center line and L is the total length (2.44 m) of the modeled furnace. The model also predicted that 10 pct of the injected coal bypasses the tuyere gas stream uncombusted and carried to the free surface by the tuyere gas stream, which

  17. Synthesis of Silicon Nitride and Silicon Carbide Nanocomposites through High Energy Milling of Waste Silica Fume for Structural Applications

    Suri, Jyothi

    Nanocomposites have been widely used in a multitude of applications in electronics and structural components because of their improved mechanical, electrical, and magnetic properties. Silicon nitride/Silicon carbide (Si 3N4/SiC) nanocomposites have been studied intensively for low and high temperature structural applications, such as turbine and automobile engine components, ball bearings, turbochargers, as well as energy applications due to their superior wear resistance, high temperature strength, high oxidation resistance and good creep resistance. Silica fume is the waste material produced during the manufacture of silicon and ferro-silicon alloys, and contains 94 to 97 wt.% SiO2. In the present dissertation, the feasibility of using waste silica fume as the raw material was investigated to synthesize (I) advanced nanocomposites of Si3N4/SiC, and (2) porous silicon carbide (SiC) for membrane applications. The processing approach used to convert the waste material to advanced ceramic materials was based on a novel process called, integrated mechanical and thermal activation process (IMTA) process. In the first part of the dissertation, the effect of parameters such as carbothermic nitridation and reduction temperature and the graphite concentration in the starting silica fume plus graphite mixture, were explored to synthesize nanocomposite powders with tailored amounts of Si3N4 and SiC phases. An effective way to synthesize carbon-free Si3N 4/SiC composite powders was studied to provide a clear pathway and fundamental understanding of the reaction mechanisms. Si3N4/SiC nanocomposite powders were then sintered using two different approaches, based on liquid phase sintering and spark plasma sintering processes, with Al 2O3 and Y2O3 as the sintering aids. The nanocomposites were investigated for their densification behavior, microstructure, and mechanical properties. Si3N4/SiC nanocomposites thus obtained were found to possess superior mechanical properties at much

  18. Total antioxidant status of zinc, manganese, copper and selenium levels in rats exposed to premium motor spirit fumes

    Patrick O Okuonghae

    2011-01-01

    Full Text Available Background: Frequent exposure to premium motor spirit (PMS is common and could be a risk factor for liver dysfunction in those occupationally exposed. A possible association between PMS fumes and plasma total antioxidant status as well as plasma levels of zinc, manganese, copper and selenium using a rodent model could provide new insights into the pathology of the liver where cellular dysfunction is an established risk factor. Aim: This study aimed to determine the total antioxidant status and plasma levels of zinc, copper, selenium and manganese in those occupationally exposed using rodent model. Materials and Methods: 25 albino Wistar rats of both sexes were used for this study. The animals were divided into five groups of five rats in each group. Group 1 rats were not exposed to PMS fumes (control group, group 2 rats were exposed for 1 hour daily, group 3 for 3 hours daily, group 4 for 5 hours daily and group 5 for 7 hours daily. The experiment lasted for a period of 4 weeks. Blood samples obtained from all the groups after 4 weeks of exposure were used for the determination of plasma total antioxidant status as well as plasma levels of zinc, manganese, copper and selenium. Results: Results showed significant increases in means of plasma copper (69.70±0.99 for test and 69.20±1.02 for control, P < 0.05 and selenium (72.70±1.58 for test and 68.20±0.86 for control, P < 0.05 in the exposed rats when respective mean values were compared with those of corresponding controls. Mean body weight index (BWI and percentage weight increase (PWI were significantly lower (P < 0.05 in exposed rats when compared with the unexposed group. The mean plasma levels of zinc (137.40±4.06 for test and 147.80±2.52 for control and manganese (65.75±1.02 for test and 70.00±0.71 for control showed significant decrease (P < 0.05 when compared with control. Plasma level of total antioxidant status (TAS did not differ significantly in exposed rats when compared with

  19. Acute dyspnea

    Radiodiagnosis is applied to determine the causes of acute dyspnea. Acute dyspnea is shown to aggravate the course of pulmonary diseases (bronchial asthma, obstructive bronchitis, pulmonary edema, throboembolism of pulmonary arteries etc) and cardiovascular diseases (desiseas of myocardium). The main tasks of radiodiagnosis are to determine volume and state of the lungs, localization and type of pulmonary injuries, to verify heart disease and to reveal concomitant complications

  20. Bronchitis (acute)

    Wark, Peter

    2008-01-01

    Acute bronchitis, with transient inflammation of the trachea and major bronchi, affects over 40/1000 adults a year in the UK. The causes are usually considered to be infective, but only around half of people have identifiable pathogens.The role of smoking or environmental tobacco smoke inhalation in predisposing to acute bronchitis is unclear.A third of people may have longer-term symptoms or recurrence.

  1. European Union Summary Risk Assessment Report - Cadmium Metal and Cadmium Oxide

    2008-01-01

    This report provides a summary, with conclusions, of the risk assessment report of the substances cadmium metal and cadmium oxide that has been prepared by Belgium in the context of Council Regulation (EEC) No. 793/93 on the evaluation and control of existing substances. For detailed information on the risk assessment principles and procedures followed, the underlying data and the literature references, the reader is referred to the comprehensive Final Risk Assessment Report (Final RAR) t...

  2. Effects of bacteria on cadmium bioaccumulation in the cadmium hyperaccumulator plant Beta vulgaris var. cicla L.

    Chen, Su; Chao, Lei; Sun, Lina; Sun, Tieheng

    2013-01-01

    To investigate the effects of two cadmium-tolerant bacteria, Staphylococcus pasteuri (S. pasteuri X1) and Agrobacterium tumefaciens (A. tumefaciens X2), on cadmium uptake by the cadmium hyperaccumulator plant Beta vulgaris var. cicla L., a pot experiment with artificially contaminated soil was conducted. The results demonstrated that both cadmium-tolerant bacteria enhanced the dry weight of Beta vulgaris var. cicla L. The total dry weights of plants in the control CK20, S. pasteuri X1 and A. tumefaciens X2 treatments were 0.85, 1.13, and 1.38 g/pot, respectively. Compared with the control CK20 findings, the total dry weight of plants was increased by 32.8 and 61.1% after inoculation with S. pasteuri X1 and A. tumefaciens X2, respectively, indicating that A. tumefaciens X2 more strongly promoted the growth of Beta vulgaris var. cicla L. than S. pasteuri X1. In addition, inoculation with S. pasteuri X1 and A. tumefaciens X2 significantly (p < 0.05) promoted cadmium uptake by plants and improved the bioaccumulation of cadmium by the plants from the soil. Moreover, the inoculation of S. pasteuri X1 and A. tumefaciens X2 effectively facilitated the transfer of cadmium in the soil from the Fe-Mn oxide and residual fractions to the soluble plus exchangeable and weakly specially adsorbed fractions in the rhizosphere soils of plants. The bacterial enhancement of cadmium phytoavailability might provide a potential and promising method to increase the efficiency of phytoextraction. PMID:23488173

  3. Impact of iron status on cadmium uptake in suckling piglets

    Low iron status is known to increase the uptake of dietary cadmium in both adolescents and adults and there are indications that cadmium is absorbed from the intestine by the two major iron transporters divalent metal transporter 1 (DMT1) and ferroportin 1 (FPN1). In addition, it has been suggested that duodenal metallothionein (MT) may limit the transport of cadmium across the intestinal epithelium. The present investigation was undertaken to examine whether iron status influences cadmium absorption in newborns by applying a model of suckling piglets and the possible roles of duodenal DMT1, FPN1 and MT. An oral cadmium dose (20 μg/kg body weight) was given daily for 6 consecutive days on postnatal days (PNDs) 10-15 to iron-deficient or iron-supplemented piglets. The cadmium dose was chosen to keep the cadmium level at a realistically low but still detectable level, and without inducing any adverse health effects in the piglets. As indicators of cadmium uptake, cadmium levels in blood and kidneys were measured on PND 16 by inductively coupled plasma-mass spectrometry (ICP-MS). Cadmium levels in blood were statistically significantly correlated with cadmium levels in kidneys. The cadmium uptake was not higher in iron-deficient suckling piglets; rather, we detected a higher cadmium uptake in the iron-supplemented ones. The expression and localisation of DMT1, FPN1 and MT were not affected by iron status and could therefore not explain the findings. Our results suggest that there are developmental differences in the handling of both iron and cadmium in newborns as compared to adults

  4. Studying the Risks of Cotton Cooking Oil Fumes on the Lung and Liver of Rats and the Protective Role of (Vitamin E Alphatocopherol

    Fahmy GAD GAD ELsaid

    2005-12-01

    Full Text Available Fumes emitted from edible vegetable cooking oils during stir- and deep-frying are important contributors to indoor air pollution. Indoor air pollution may be increase the lung and liver cancer in Egypt in 2005. Therefore, the present study was undertaken to investigate the effects of Egyptian cotton cooking oil fumes on rats. The exposed rats for 30 and 60 days to cotton oil fumes showed a significant increase in the lung and liver malondialdehyde levels which accompanied with a significant decrease in glutathione content. Also, there was a significant decrease in lung and liver superoxide dismutase, catalase, glutathione s-transferase activities. As well as, there was a significant decrease in serum amino acids levels, lung and liver nucleic acids and total proteins. These changes were obviously after 60 days than that of 30 days of exposure. DNA change was clear in the lungs of rats after cotton oil fumes exposed as showed by the differential display technique, P53 primer which used to study the expression of the p35 gene as well as to confirm and amplify these changes after oil fumes exposure. Band with different molecular weights were observed after the exposure and in protected groups but not presented in the control. More characterization for the changes had been carried out in the animal on two levels, one the DNA using RAPD-PCR and the other on the protein level using SDS-PAGE techniques. Also, vitamin E ameliorates these abnormalities to extent limit in all cases in this work.

  5. Influence of static magnetic field on cadmium toxicity: study of oxidative stress and DNA damage in pregnant rat tissues.

    Chater, Sihem; Douki, Thierry; Favier, Alain; Garrel, Cathrine; Sakly, Mohsen; Abdelmelek, Hafedh

    2008-01-01

    In our environment, we have numerous chances to be exposed to not only static magnetic fields (SMFs) but also many chemicals containing mutagens. Therefore, the aim of this study was to investigate the effects of co-exposure to SMF and cadmium (Cd) on the antioxidant enzymes activity and DNA damage in pregnant rat tissues. Pregnant rats were treated with cadmium (CdCl(2), 3.0 mg/Kg body weight) or exposed to SMF (128 mT/h/day) and treated with cadmium chlorides (3.0 mg/kg, body weight) for 13 consecutive days as from the 6th to 19th day of gestation. Cd treatment increased malondialdehyde (MDA) and 8-oxodGuo levels in kidney of pregnant rats. However, the activity of superoxide dismutase (SOD) and glutathione level were decreased in kidney. Interestingly, the combined effects of SMF and Cd have no effects on activities of antioxidant in both tissues compared to cadmium treated group. However, the association between SMF and Cd decreased plasma MDA concentration. The same treatment failed to alter 8-oxodGuo concentration. Sub-acute Cd treatment altered antioxidant enzymes and DNA in kidney of pregnant rats. The results suggest that a homeostatic defence mechanism was activated when SMF was associated to Cd in pregnant rats. PMID:19037788

  6. Accumulation of cadmium by transgenic tobacco

    Macek, Tomáš; Macková, M.; Pavlíková, D.; Száková, J.; Truks, M.; Singh Cundy, A.; Kotrba, P.; Yancey, N.; Scouten, W. H.

    2002-01-01

    Roč. 22, 1/2 (2002), s. 101-106. ISSN 0138-4988 R&D Projects: GA ČR GA526/02/0293 Institutional research plan: CEZ:AV0Z4055905 Keywords : phytoremediation * cadmium Subject RIV: CE - Biochemistry Impact factor: 0.542, year: 2002

  7. Cadmium isotope variations in the Southern Ocean

    Xue, Z.; Rehkämper, M.; Horner, T.J.; Abouchami, W.; Middag, R.; van de Flierd, T.; de Baar, H.J.W.

    2013-01-01

    Cadmium concentrations and isotope compositions were determined for 47 seawater samples from the high nutrient low chlorophyll (HNLC) zone of the Atlantic sector of the Southern Ocean. The samples include 13 surface waters from a transect of the Weddell Gyre and 3 depth profiles from the Weddell Sea

  8. Physicochemical properties of a cadmium telluride surface

    Change of chemical state of cadmium telluride surface is investigated after different treatments (exposure in air, vacuum, gaseous media, γ- and IR-irradiation). The results of these investigations are of great interest for clarifying the nature of active surface of diamond-like semiconductors, the mechanism of its interaction with different media and the possibilities of surface properties regulation

  9. The effect of cadmium on plant metabolism

    Pavlíková, D.; Pavlík, Milan; Vokáč, Karel; Balík, J.; Szaková, J.; Tlustoš, P.

    Budapest : Institute of Materials and Environmental Chemistry, 2006. s. 71. [International Symposium on Trace Element in the Food Chain . 25.05.2006-27.05.2006, Budapest] Institutional research plan: CEZ:AV0Z40550506 Keywords : cadmium * plant metabolism * glutamate kinase Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides

  10. The effect of cadmium on plant metabolism

    Pavlíková, D.; Pavlík, Milan; Vokáč, Karel; Staszková, L.; Balík, J.; Szaková, J.; Tlustoš, P.

    Budapest : Institute of Materials and Environmental Chemistry, 2006 - (Szilágyi, M.; Szentmihályi, K.), 256-260 [Trace Elements in the food chain . Budapest (HU), 25.05.2006-27.05.2006] Institutional research plan: CEZ:AV0Z40550506 Keywords : cadmium * plant metabolism * glutamate kinase Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides

  11. Temperature dependence of autogenous shrinkage of silica fume cement pastes with a very low water–binder ratio

    Maruyama, I., E-mail: ippei@dali.nuac.nagoya-u.ac.jp [Graduate School of Environmental Studies, Nagoya University, ES Building, No. 539, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Teramoto, A. [Graduate School of Environmental Studies, Nagoya University, Faculty of Engineering, ES Building, No. 546, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2013-08-15

    Ultra-high-strength concrete with a large unit cement content undergoes considerable temperature increase inside members due to hydration heat, leading to a higher risk of internal cracking. Hence, the temperature dependence of autogenous shrinkage of cement pastes made with silica fume premixed cement with a water–binder ratio of 0.15 was studied extensively. Development of autogenous shrinkage showed different behaviors before and after the inflection point, and dependence on the temperature after mixing and subsequent temperature histories. The difference in autogenous shrinkage behavior poses problems for winter construction because autogenous shrinkage may increase with decrease in temperature after mixing before the inflection point and with increase in temperature inside concrete members with large cross sections.

  12. Suppression of Aluminum Corrosion in Lithium Bis(trifluoromethanesulfonyl)imide-based Electrolytes by the Addition of Fumed Silica

    Louis, Hamenu; Ko, Jangmyoun [Hanbat National Univ., Daejeon (Korea, Republic of); Lee, Younggi; Kim, Kwangman [Electronics and Telecommunications Research Institute, Daejeon (Korea, Republic of); Cho, Wonil [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

    2013-06-15

    The corrosion property of aluminum by lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt is investigated in liquid and gel electrolytes consisting of ethylene carbonate/propylene carbonate/ethylmethyl carbonate/diethyl carbonate (20:5:55:20, vol %) with vinylene carbonate (2 wt %) and fluoroethylene carbonate (5 wt %) using conductivity measurement, cyclic voltammetry, scanning electron microscopy, and energy dispersive X-ray spectroscopy. All corrosion behaviors are attenuated remarkably by using three gel electrolytes containing 3 wt % of hydrophilic and hydrophobic fumed silica. The addition of silica particles contributes to the increase in the ionic conductivity of the electrolyte, indicating temporarily formed physical crosslinking among the silica particles to produce a gel state. Cyclic voltammetry also gives lower anodic current responses at higher potentials for repeating cycles, confirming further corrosion attenuation or electrochemical stability. In addition, the degree of corrosion attenuation can be affected mainly by the electrolytic constituents, not by the hydrophilicity or hydrophobicity of silica particles.

  13. Cr(VI Removal from Aqueous by Adsorption on Amine-Functionalized Mesoporous Silica Prepared from Silica Fume

    Xitong Li

    2014-01-01

    Full Text Available Amino-functionalized mesoporous silica MCM-41 materials have been prepared to develop efficient adsorbents of Cr(VI in wastewater, using silica fume as silica source. Functionalization with amino groups has been carried out by using grafting method. The materials have been characterized by means of X-ray diffraction (XRD, nitrogen (N2 adsorption-desorption, Fourier transform infrared (FTIR spectroscopy, scanning electron microscopy (SEM, transmission electron microscopy (TEM, and X-ray photoelectron spectroscopy (XPS. Adsorption potential of the material for Cr(VI removal from aqueous solution was investigated by varying experimental conditions such as pH, initial metal concentration, and contact time. The equilibrium data were analyzed using the Langmuir and Freundlich isotherm by linear regression analysis, and the results show that the adsorption equilibrium data obeyed the Langmuir model. In addition, the kinetics analysis revealed that the overall adsorption process was successfully fitted with the pseudo-second-order kinetic model.

  14. Influence of copper content of steel welding wires on the fume formation rate in gas metal arc welding

    Increase in the fume formation rate (FFR) during welding with copper-coated wires has been attributed to the copper coating. However, instability during the welding process can have an influence on the FFR. To overcome this problem, the University of Wollongong has developed an auto-control system that can minimise the influence of the instability and thus allow more accurate determination of the FFR in the 'drop-spray' mode of transfer. Investigation of the FFR associated with gas metal arc welding using copper-coated wires in the drop-spray mode confirmed that an increase in the FFR of copper-coated welding wires does occur, but the increase was not found to be directly proportional to the increase in copper content of the wire.

  15. Temperature dependence of autogenous shrinkage of silica fume cement pastes with a very low water–binder ratio

    Ultra-high-strength concrete with a large unit cement content undergoes considerable temperature increase inside members due to hydration heat, leading to a higher risk of internal cracking. Hence, the temperature dependence of autogenous shrinkage of cement pastes made with silica fume premixed cement with a water–binder ratio of 0.15 was studied extensively. Development of autogenous shrinkage showed different behaviors before and after the inflection point, and dependence on the temperature after mixing and subsequent temperature histories. The difference in autogenous shrinkage behavior poses problems for winter construction because autogenous shrinkage may increase with decrease in temperature after mixing before the inflection point and with increase in temperature inside concrete members with large cross sections

  16. Polycyclic aromatic hydrocarbons in ultrafine particles of diesel exhaust fumes – The use of ultrafast liquid chromatography

    Małgorzata Szewczyńska

    2014-10-01

    Full Text Available Background: The article presents the results of the determination of polycyclic aromatic hydrocarbons (PAHs in the fine particles fraction emitted from 3 types of diesel fuels using ultra-high pressure liquid chromatography. Material and Methods: Samples of diesel Eco, Verwa and Bio exhaust combustion fumes were generated at the model station which consisted of a diesel engine from the 2007 Diesel TDI 2.0. Personal Cascade Sioutas Impactor (PCSI with Teflon filters was used to collect samples of exhaust fume ultrafine particles. PAHs adsorbed on particulate fractions were analyzed by ultra-high pressure liquid chromatography with fluorescence detection (UHPLC/FL. Results: Phenanthrene, fluoranthene, pyrene and chrysene present the highest concentration in the particulate matter emitted by an engine. The total contents of fine particles collected during engine operation on fuels Eco, Verwa and Bio were 134.2 μg/g, 183.8 μg/g and 153.4 μg/g, respectively, which makes 75%, 90% and 83% of the total PAHs, respectively. The highest content of benzo(apyrene determined in particles emitted during the combustion of fuels Eco and Bio was 1.5 μg/g and 1 μg/g, respectively. Conclusions: The study of the PAH concentration in the particles of fine fraction below 0.25 μm emitted from different fuels designed for diesel engines indicate that the exhaust gas content of carcinogens, including PAHs deposited on particulates, is still significant, regardless of the fuel. Application of ultrahigh pressure liquid chromatography with fluorescence detection for the analysis of PAHs in the particles emitted in the fine fraction of diesel exhaust allowed to shorten the analysis time from 35 min to 8 min. Med Pr 2014;65(5:601–608

  17. Cadmium phytoextraction potential of different Alyssum species

    Highlights: ► The possibility of using serpentine plants for phytoextraction of Cd was investigated. ► Variation in Cd tolerance, accumulation and translocation in three Alyssum plants with different phenotypes were found. ► Alyssum montanum showed higher Cd tolerance and accumulation than the Ni hyperaccumulator Alyssum bertolonii. ► As for the kinetic parameters of the Cd uptake system, A. montanum presented a low apparent Km value. ► The Vmax values were not significantly different among the plants. - Abstract: This work was planned for providing useful information about the possibility of using serpentine adapted plants for phytoextraction of cadmium, element scarcely represented in such metalliferous environment. To this aim, we investigated variation in cadmium tolerance, accumulation and translocation in three Alyssum plants with different phenotypes: Alyssum bertolonii, that is a serpentine endemic nickel hyperaccumulator, and two populations of Alyssum montanum, one adapted and one not adapted to serpentine soils. Plants were hydroponically cultivated in presence of increasing concentrations of CdSO4 for two weeks. For the metal concentration used in the experiments, the three different Alyssum populations showed variation in cadmium tolerance, accumulation and content. The serpentine adapted population of A. montanum showed statistically higher cadmium tolerance and accumulation than A. bertolonii and the population of A. montanum not adapted to serpentine soil thus deserving to be investigated for phytoextraction purposes. Furthermore, as for the kinetic parameters of the cadmium uptake system, A. montanum serpentine population presented a low apparent Km value, suggesting a high affinity for this metal of its uptake system, whereas the Vmax values were not significantly different among the plants. Present data revealed metallicolous plants are also suitable for the phytoremediation of metals underrepresented in the environment of their initial

  18. Cadmium and Chrome Concentrations in Human Milk

    Sima Nazarpour

    2014-04-01

    Full Text Available Introduction: Nutrition of children has the highest priority in any program aimed at children's health care. Milk contaminated with various toxic elements can have adverse effects on children's health. This study aimed to determine the concentration of heavy metals including cadmium(Cd and chromium (Cr of breast feeding women’s milk in Varamin. Methods: This is a cross sectional study. In the present study, chromium and cadmium levels in milk of 100 mothers attending clinics in the city of Varamin were measured in four to eight weeks after delivery, using atomic absorption spectrometry. Results: The mean values (±SD of Cd and Cr in human milk were 5±6.9 μg/ml and 3±2.7 μg/ml respectively. Result of Linear regression showed that cadmium levels were higher in breast milk of people living close to the factory or industrial center. Also, the chromium levels were higher in the breast milk of women in cases of: Smoking by spouses, consumption of imported rice, consumption of mineral water, and living close to the factory or an industrial center. Conclusion: This study showed that the relationship of some factors such as living near a factory or an industrial center, smoking by spouse, the type of consumed rice and water, with the level of cadmium and chromium. Cadmium and chromium levels of breast milk in this study were higher than the levels of these elements mentioned in the reviewed articles and international standard. Because some variables, such as living near a factory or an industrial center, smoking by spouse, the type of consumed rice and water can affect the amount of entering elements in breast milk. Actions can be taken to reduce or eliminate these variables in order to decrease the mentioned elements in human milk.

  19. Cadmium phytoextraction potential of different Alyssum species

    Barzanti, R., E-mail: rbarzanti@supereva.it [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Colzi, I., E-mail: ilariacolzi@hotmail.it [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Arnetoli, M., E-mail: miluscia@gmail.com [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Gallo, A., E-mail: galloalessia@hotmail.com [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Pignattelli, S., E-mail: sara.pignattelli@gmail.com [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Gabbrielli, R., E-mail: gabbrielli@unifi.it [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Gonnelli, C., E-mail: cristina.gonnelli@unifi.it [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy)

    2011-11-30

    Highlights: Black-Right-Pointing-Pointer The possibility of using serpentine plants for phytoextraction of Cd was investigated. Black-Right-Pointing-Pointer Variation in Cd tolerance, accumulation and translocation in three Alyssum plants with different phenotypes were found. Black-Right-Pointing-Pointer Alyssum montanum showed higher Cd tolerance and accumulation than the Ni hyperaccumulator Alyssum bertolonii. Black-Right-Pointing-Pointer As for the kinetic parameters of the Cd uptake system, A. montanum presented a low apparent K{sub m} value. Black-Right-Pointing-Pointer The V{sub max} values were not significantly different among the plants. - Abstract: This work was planned for providing useful information about the possibility of using serpentine adapted plants for phytoextraction of cadmium, element scarcely represented in such metalliferous environment. To this aim, we investigated variation in cadmium tolerance, accumulation and translocation in three Alyssum plants with different phenotypes: Alyssum bertolonii, that is a serpentine endemic nickel hyperaccumulator, and two populations of Alyssum montanum, one adapted and one not adapted to serpentine soils. Plants were hydroponically cultivated in presence of increasing concentrations of CdSO{sub 4} for two weeks. For the metal concentration used in the experiments, the three different Alyssum populations showed variation in cadmium tolerance, accumulation and content. The serpentine adapted population of A. montanum showed statistically higher cadmium tolerance and accumulation than A. bertolonii and the population of A. montanum not adapted to serpentine soil thus deserving to be investigated for phytoextraction purposes. Furthermore, as for the kinetic parameters of the cadmium uptake system, A. montanum serpentine population presented a low apparent K{sub m} value, suggesting a high affinity for this metal of its uptake system, whereas the V{sub max} values were not significantly different among the

  20. Acute myelogenous leukemia (AML) - children

    Acute myelogenous leukemia - children; AML; Acute myeloid leukemia - children; Acute granulocytic leukemia - children; Acute myeloblastic leukemia - children; Acute non-lymphocytic leukemia (ANLL) - children

  1. Cadmium-induced fetal toxicity in the rat

    Cadmium, a heavy metal environment contaminant, induces fetal death and placental necrosis in the Wistar rat. This study investigated fetal, maternal, and placental responses to cadmium intoxication. Subcutaneous injection of CdCl2 to dams on day 18 of pregnancy produced a high incidence of fetal death (75%) and placental necrosis. Death in the fetus was produced despite limited fetal accumulations of cadmium. Distribution studies using 109Cd-labeled CdCl2 demonstrated that less than 0.1% of the injected dose was associated with the fetus. To determine if fetuses were sensitive to these low levels of cadmium, direct injections of CdCl2 into fetuses were performed in utero. Direct injections produced fetal accumulations 8-fold greater than those following maternal injections. The 8-fold greater fetal accumulations following direct injection were associated with only a 12% fetal mortality compared to the 75% mortality following maternal injections. The data indicated that the fetal toxicity of cadmium following maternal injections was not the result of direct effects of cadmium on the fetus. In conclusion, cadmium-induced fetal death was not the result of direct effects of cadmium on the fetus but may have been induced by placental cellular injury resulting from high accumulations of cadmium in the placenta. A vascular response to placental injury, leading to decreased utero-placental bood flow and cadmium-induced alterations in trophoblastic function, resulted in fetal death

  2. Cadmium and lead elimination through milk in the ewe

    Houpert, P.; Mehennaoui, S.; Federspiel, B.; Milhaud, G. [Equipe associee INRA-ENV Alfort, 94 - Maisons-Alfort (France)

    1997-12-31

    Cadmium and lead are heavy metals widely distributed in industrialized countries, and known for their cumulative properties in continental ecological cycling. The purpose of the experiments was to study lead and cadmium transfer from ewe feed to their milk and meat, in view of protecting human consumers. Ewes were given daily oral administrations of lead, cadmium or associations of lead-cadmium, lead-cadmium-zinc for 52 days. Lead and cadmium were measured in blood, milk and tissues. About 0.1 pc of the total lead and 0.002-0.004 pc of the total cadmium dose was excreted via milk during the lactation, with milk concentrations of about 120 microgram per liter for lead and about 3.5 micro-g./l for cadmium. Sixty days after the last administration, 0.16 pc of the total cadmium dose was retained in liver and 0.09 pc in kidneys. Cadmium and lead concentrations in the muscle remained low

  3. Modelling of Cadmium Transport in Soil-Crop System

    2000-01-01

    A model for simulating cadmium transport in a soil-plant system was built using a commercial simu lating program named Powersim on the basis of input-output processes happening in the soil-plant system.Convective and dispersive transport processes of cadmium in soil profile are embedded. Simulations on a daily base have been done up to a total simulating time of 250 years. Results show that applications of sewage sludge and fertilizer at the simulated rates would only cause slight cadmium accumulations in each layer of the soil, and cadmium accumulation would be levelling off, reaching an equilibrium concentrations layer by layer downward after certain time. The time scale to reach an equilibrium concentration varies from 10 years for the top three layers to over 250 years for the bottom layers. Plant cadmium uptake would increase from 52 ug m-2 under initial soil cadmium concentrations to 65 μg m-2 under equilibrium soil cadmium concentrations, which would not exceed the maximum allowable cadmium concentration in wheat grains. Main parameters which influence cadmium accumulation and transport in soil are total cadmium input, rainfall, evaporation, plant uptake and soil properties.

  4. Accumulation of cadmium in livers and kidneys in Greenlanders

    In the Arctic, the traditional diet exposes its people to a very high intake of cadmium because it is highly concentrated in the liver and kidneys of commonly eaten marine mammals. In one study in Greenland, the cadmium intake was estimated to 182 μg/day/person in the fall and 346 in the spring. To determine whether the cadmium is accumulated in humans, we analyzed autopsy samples of liver and kidneys from 95 ethnic Greenlanders (aged 19-89) who died from a wide range of causes. The cadmium concentration in liver (overall mean 1.97 μg/g wet wt) appeared to be unrelated to any particular age group, whereas the concentrations in the kidneys peaked in Greenlanders between 40 and 50 years of age (peak concentration 22.3 μg/g wet wt). Despite the high cadmium levels in the typical Greenlander diet, we found that the cadmium concentrations in livers and kidneys were comparable to those reported from Denmark, Sweden, Australia and Great Britain. Furthermore, even though the mean cadmium intake from the diet was estimated to be 13-25 times higher in Greenlanders than in Danes, we found similar cadmium levels in the kidneys of both. Seal livers and kidneys are the main source of cadmium in the diet of Greenlanders, but these tissues are not eaten in Denmark. Thus, our results suggest that the accumulation of cadmium from Greenlander's marine diet is very low

  5. Determination of Informal Sector as Urban Pollution Source : Fume Characterization of Small-scale Manual Metal Arc Welding using Factor Analysis in Bandung City

    A. Nastiti

    2012-04-01

    Full Text Available In developing countries, the informal sector, particularly small-scale welding activities, are considered to be an important contributor to urban air pollution although studies in this sector are limited. This study aims to identify the composition of small-scale welding fume in order to further investigate the effects and set control strategies and urban pollution abatement policies. Breathing zone air samples were collected from 30 mild steel manual metal arc welders and 17 non-welders in Bandung City, West Java, Indonesia. The respirable particulates in air samples were analyzed using gravimetric method, and Instrumental Neutron Activation Analysis (INAA was employed to identify characteristic of welding fume. It was found that respirable particulates concentration in welders (range : 315.6 and 3,735.93 µgm-3; average 1,545.436 µgm-3 were significantly higher than in non-welders (range : 41.84 and 1,688.03 µgm-3; average : 375.783 µgm-3. Welders’ breathing zones contain Fe>Na>K>Mn>Al >Cr>Ti>Cl>Br>I>Zn>Sb>V>Co>Sc; while non-welders’ breathing zones contain Cr>F>Al>Ti>Na>Br>I>Mn>Cl>Co>Zn>Sc. Inter-species correlation analysis conducted using Statgraphic Ver. 4.0 shows that Fe (range : n.d. – 775.19 µgm-3; average: 0.1674 µgm-3, Co (range : n.d. – 0.51 µgm-3; average: 0.000082 µgm-3, Mn (range : 0.39 – 148.37 µgm-3; average: 0.0374 µgm-3, Na (range: 0.17 and 623.85 µgm-3; average: 0.0973 µgm-3 and K (range : n.d. – 301.15 µgm-3; average: 0.0535 µgm-3 were emitted from welding activity, and thus are considered as components of welding fume which contribute to urban air pollution. Although welding fume and the identified species in welding fume were still below permissible limit, small-scale welding activities have great potential in emitting higher fume concentration due to due to high variability of welding activities, such as welding frequency, materials being welded, and varied environmental conditions

  6. Determination of Informal Sector as Urban Pollution Source : Fume Characterization of Small-scale Manual Metal Arc Welding using Factor Analysis in Bandung City

    In developing countries, the informal sector, particularly small-scale welding activities, are considered to be an important contributor to urban air pollution although studies in this sector are limited. This study aims to identify the composition of small-scale welding fume in order to further investigate the effects and set control strategies and urban pollution abatement policies. Breathing zone air samples were collected from 30 mild steel manual metal arc welders and 17 non-welders in Bandung City, West Java, Indonesia. The respirable particulates in air samples were analyzed using gravimetric method, and Instrumental Neutron Activation Analysis (INAA) was employed to identify characteristic of welding fume. It was found that respirable particulates concentration in welders (range : 315.6 and 3,735.93 µgm-3; average 1,545.436 µgm-3) were significantly higher than in non-welders (range : 41.84 and 1,688.03 µgm-3; average : 375.783 µgm-3). Welders' breathing zones contain Fe>Na>K>Mn>Al >Cr>Ti>Cl>Br>I>Zn>Sb>V>Co>Sc; while non-welders' breathing zones contain Cr>F>Al>Ti>Na>Br>I>Mn>Cl>Co>Zn>Sc. Inter-species correlation analysis conducted using Statgraphic Ver. 4.0 shows that Fe (range : n.d. - 775.19 µgm-3; average: 0.1674µgm-3), Co (range : n.d. - 0.51 µgm-3; average: 0.000082 µgm-3), Mn (range : 0.39 - 148.37 µgm-3; average: 0.0374 µgm-3), Na (range: 0.17 and 623.85 µgm-3; average: 0.0973 µgm-3) and K (range : n.d. - 301.15 µgm-3; average: 0.0535 µgm-3) were emitted from welding activity, and thus are considered as components of welding fume which contribute to urban air pollution. Although welding fume and the identified species in welding fume were still below permissible limit, small-scale welding activities have great potential in emitting higher fume concentration due to due to high variability of welding activities, such as welding frequency, materials being welded, and varied environmental conditions. (author)

  7. Glutathione S-transferase in the midgut tissue of gypsy moth (Lymantria dispar) caterpillars exposed to dietary cadmium.

    Vlahović, Milena; Ilijin, Larisa; Mrdaković, Marija; Todorović, Dajana; Matić, Dragana; Lazarević, Jelica; Mataruga, Vesna Perić

    2016-06-01

    Activity of glutathione S-transferase (GST) in midgut of gypsy moth caterpillars exposed to 10 and 30μg Cd/g dry food was examined. Based on the enzyme reaction through conjugation with glutathione, overall activity remained unaltered after acute and chronic treatment. No-observed-effect-concentration (10μg Cd/g dry food) significantly increased activity only after 3-day recovery following cadmium administration. Almost all comparisons of the indices of phenotypic plasticity revealed statistically significant differences. Despite the facts that GST has important role in xenobiotic biotransformation, our results indicate that this enzyme in insect midgut does not represent the key factor in cadmium detoxification. PMID:27084993

  8. Cadmium uptake in oyster isognomon alatus under laboratory condition

    The uptake of cadmium in Flat tree oyster Isognomon alatus was investigated under controlled laboratory conditions for two weeks. Oysters were exposed to 100 μg 1'-1 cadmium and the accumulation of cadmium in the tissues was measured for every two days. Soft tissues of oyster were digested in concentrated acid and cadmium concentrations were determined by using Atomic Absorption Spectrophotometer. The accumulation of cadmium in the soft tissues of oysters was increased during the first six days from 0.73 μg g- 1 to 10.77 μg g'-1, and remaining constant for four days at average level of 10.96 μg g'-1. The Cl concentrations was increased to 32.70 μg g'-1 until the end of experiment. There was no sign of cadmium accumulation approaching saturation for the period of exposure. (author)

  9. Study on electrokinetic remediation of cadmium contaminated soils

    SHI Wen-xin; CUI Chong-wei; YU Shui-li; FENG Wei-ming

    2007-01-01

    Kaolinite from a lead-zinc mining district, which was spiked with cadmium, has been treated by electrokinetics to investigate effects of treatment time and applied voltage gradient. The results showed that the increased test duration had induced a higher removal rate of cadmium. Being treated for 7 days, cadmium was removed from kaolinite dramatically. It was also found that higher removal rate happened when a higher voltage gradient was applied and cadmium accumulated near the cathode because pH increased. Increase of pH near the cathode caused accumulation of cadmium. Moreover, it was observed that cation exchange membrane which was placed between kaolinite and cathode could make pH lower than the initial value and avoid the higher pH near the cathode. As a result, the high concentration accumulation of cadmium near the cathode was avoided.

  10. Research and Development of Cadmium Sulphoselenide Red Pigment

    WU Jianfeng; LI Kun; XU Xiaohong; ZHANG Yaxiang; XU Xiaoyang; LAO Xinbin

    2015-01-01

    Cadmium sulphoselenide was synthesized continuous substitution solid solution and the only known pigment to yield bright red color on ceramic decoration. Encapsulated cadmium sulphoselenide pigments could yield abundant hues from yellow to red with high opacity at high temperature. The color generation has a linear function relation with the substitution rate. The encapsulation formation process of zirconium silicate encapsulated cadmium sulphoselenide was shown. Insufifcient encapsulation efifciency and potential hazard to human and environment had limited the industrial application of cadmium sulphoselenide red pigment. Ink-jet printing decoration required ifne size cadmium sulphoselenide red pigment on ceramic decoration. The review mainly focused on the synthesis techniques and industrial application of cadmium sulphoselenide red pigment.

  11. Cadmium filtered neutron flux determination. Comparison of activation methods

    Neutron fluxes under cadmium filters are determined by the cadmium ratio and sandwich activation methods. The thermal neutron flux levels obtained with 7 detectors of different kinds: In, Au, Ag, W, Co, Mn, Zn are compared. The cadmium ratio method was used in locations for which the epithermal and thermal neutron flux ratio are quite different. By irradiating materials under different thicknesses of cadmium it was possible to establish experimental curves from which the flux depression factors for intermediate neutrons may be determined whatever the thickness of the filter used. Whereas the cadmium ratio method can only measure the mean flux above the cadmium cut-off energy the sandwich method enables the flux value to be determined in a narrow band around the resonance energy of each detector used

  12. In search of biomonitors for cadmium: cadmium content of wild Swedish fauna during 1973-1976.

    Frank, A

    1986-12-01

    Forty-five species of birds and 22 species of mammals of the terrestrial and aquatic fauna, herbivores as well as carnivores, were investigated during the period 1973-1976 for cadmium-accumulating properties in order to find biomonitors for cadmium in the Swedish environment. The herbivores of the terrestrial fauna, birds as well as mammals, are preferred to carnivores, since they demonstrate generally higher renal Cd levels. The moose (Alces alces), roe deer (Capreolus capreolus) and hare (Lepus europeus and Lepus timidus) were found to be suitable as biomonitors because of their common occurrence and uniform geographical distribution. The eider duck (Somateria mollissima), although a short-distance migrating bird whose diet is composed mainly of mussels and crustaceans, and which lives along a great part of the Swedish coastline, is suggested as a biomonitor of cadmium for the aquatic environment. The accumulation rate of cadmium in the kidneys is rapid. Renal levels of cadmium in the parts per million range are reached 10 weeks after hatching. Juvenile birds should be collected for monitoring purposes before leaving their feeding domains at the end of the summer. PMID:3810147

  13. Growth of cadmium oxide whiskers on cadmium sulphide single crystals with copper as growth activator

    Some results on the growth and morphology of cadmium oxide whiskers, obtained on cadmium sulphide single crystals with copper as a growth activator, are presented in this work. Cadmium oxide whiskers have been obtained on brace 112-bar0 brace faces of cadmium sulphide plates with a copper layer deposited in advance. The whiskers grew during the annealing of the plates in a weak stream of technically pure argon at temperatures 670 to 730 deg C for 15 min to 3.5 h. Details about the procedure have been given elsewhere. The composition and morphology of the whiskers have been studied by an X-ray microanalyser JEOL 35 DDS and a scanning electron microscope JEOL, JSM 35. The optical microscopic observations have shown that after annealing, a gray-black granular layer is formed on the cadmium sulphide single crystals and this layer can easily be separated from the crystal substrate. Under the granular layer the crystal is heavily damaged. The whiskers grow on the granular layer and they are coloured yellow-brown or red-brown. The maximum whisker length attains several hundreds of micrometres and in some cases up to 1 mm or more. (author)

  14. Growth of cadmium oxide whiskers on cadmium sulphide single crystals with copper as growth activator

    Koparanova, N.; Simov, S. (Bylgarska Akademiya na Naukite, Sofia. Inst. po Fizika na Tvyrdoto Tyalo); Genchev, D. (Bylgarska Akademiya na Naukite, Sofia. Inst. za Yadrena Izsledvaniya i Yadrena Energetika); Metchenov, G. (Research Inst. of Criminalistics and Criminology, Sofia (Bulgaria))

    1985-02-01

    Some results on the growth and morphology of cadmium oxide whiskers, obtained on cadmium sulphide single crystals with copper as a growth activator, are presented in this work. Cadmium oxide whiskers have been obtained on brace 112-bar0 brace faces of cadmium sulphide plates with a copper layer deposited in advance. The whiskers grew during the annealing of the plates in a weak stream of technically pure argon at temperatures 670 to 730 deg C for 15 min to 3.5 h. Details about the procedure have been given elsewhere. The composition and morphology of the whiskers have been studied by an X-ray microanalyser JEOL 35 DDS and a scanning electron microscope JEOL, JSM 35. The optical microscopic observations have shown that after annealing, a gray-black granular layer is formed on the cadmium sulphide single crystals and this layer can easily be separated from the crystal substrate. Under the granular layer the crystal is heavily damaged. The whiskers grow on the granular layer and they are coloured yellow-brown or red-brown. The maximum whisker length attains several hundreds of micrometres and in some cases up to 1 mm or more.

  15. Oral cadmium exposure of adults in Germany. 1: Cadmium content of foodstuffs and beverages.

    Müller, M; Anke, M; Hartmann, E; Illing-Günther, H

    1996-04-01

    The cadmium contents of 94 and 105 foodstuffs bought in six-fold repetition in 1988 and in nine-fold repetition in 1991, respectively were analysed within the framework of a market-basket study. These foodstuffs were typical of German eating habits. Additionally, 170 samples of drinking water were investigated. The cadmium concentrations of the foodstuffs were comparable with results of recent studies carried out in Europe and North America. Fruit, milk and dairy products, sugar and sugar-rich foodstuffs as well as beverages showed mean cadmium contents cakes and pastries as well as farinaceous products were within the range of 20-40 ng/g. The most important bread, cakes and pastries (wheat and rye bread, toasted bread, rolls) contained 25-35 ng/g. A median cadmium concentration of 0.2 micrograms/l was found in the drinking water. As expected, liver and kidneys showed the highest cadmium levels of 73 and 204 ng/g, respectively on average. PMID:8718751

  16. Urinary cadmium and mammographic density in premenopausal women.

    Adams, Scott V; Newcomb, Polly A; Shafer, Martin M; Atkinson, Charlotte; Bowles, Erin J Aiello; Newton, Katherine M; Lampe, Johanna W

    2011-08-01

    Mammographic density (MD), a strong marker of breast cancer risk, is influenced by genetic, environmental, and hormonal factors. Cadmium, a persistent and widespread environmental pollutant, has been associated with risk of breast cancer, and laboratory evidence suggests cadmium is a carcinogen in the breast. We investigated the hypothesis that cadmium exposure is associated with higher MD. In a cross-sectional study of MD and urinary cadmium concentration, percentage MD (MD%) and Breast Imaging-Reporting and Data Systems (BI-RADS®) density category were determined from screening mammograms of 190 premenopausal women ages 40-45 years. Women completed a health questionnaire, and the cadmium content of spot urine samples was measured with inductively coupled plasma mass spectrometry and corrected for urine creatinine. Urinary cadmium concentrations are thought to reflect exposure to cadmium during a period of 20-30 years. Multivariable linear regression and logistic regression were used to estimate the strength of association between urinary cadmium and mammographic breast density. Adjusted mean MD% among women in the upper tertile of creatinine-corrected urinary cadmium was 4.6% higher (95% CI: -2.3 to 11.6%) than in women in the lowest cadmium tertile. Each twofold increase in urinary cadmium was associated with higher odds of MD% in the upper tertile (OR: 1.29, 95% CI: 0.82-2.02) or a BI-RADS category rating of "extremely dense" (OR: 1.75, 95% CI: 1.14-2.70). Stronger associations were observed among nulliparous women, and current or former smokers. Exposure to cadmium may be associated with increased breast density in premenopausal women. PMID:21327468

  17. The effects of low environmental cadmium exposure on bone density

    Recent epidemiological data indicate that low environmental exposure to cadmium, as shown by cadmium body burden (Cd-U), is associated with renal dysfunction as well as an increased risk of cadmium-induced bone disorders. The present study was designed to assess the effects of low environmental cadmium exposure, at the level sufficient to induce kidney damage, on bone metabolism and mineral density (BMD). The project was conducted in the area contaminated with cadmium, nearby a zinc smelter located in the region of Poland where heavy industry prevails. The study population comprised 170 women (mean age=39.7; 18-70 years) and 100 men (mean age=31.9; 18-76 years). Urinary and blood cadmium and the markers of renal tubular dysfunction (β2M-U RBP, NAG), glomerular dysfunction (Alb-U and β2M-S) and bone metabolism markers (BAP-S, CTX-S) as well as forearm BMD, were measured. The results of this study based on simple dose-effect analysis showed the relationship between increasing cadmium concentrations and an increased excretion of renal dysfunction markers and decreasing bone density. However, the results of the multivariate analysis did not indicate the association between exposure to cadmium and decrease in bone density. They showed that the most important factors that have impact on bone density are body weight and age in the female subjects and body weight and calcium excretion in males. Our investigation revealed that the excretion of low molecular weight proteins occurred at a lower level of cadmium exposure than the possible loss of bone mass. It seems that renal tubular markers are the most sensitive and significant indicators of early health effects of cadmium intoxication in the general population. The correlation of urinary cadmium concentration with markers of kidney dysfunction was observed in the absence of significant correlations with bone effects. Our findings did not indicate any effects of environmental cadmium exposure on bone density.

  18. Evaluation of aluminium–based coatings for cadmium replacement

    Chalaftris, George

    2003-01-01

    Cadmium electroplating is widely used in the aerospace industry for the corrosion protection of aircraft components like fasteners manufactured from non corrosion resisting high strength steels. However, environmental and safety concerns over the high toxicity of cadmium and its compounds have led to the investigation of suitable replacements. Alternatives to cadmium should offer effective corrosion protection and have no detrimental effects on the steel substrate. Hydrogen is known to be abs...

  19. Hepatotoxicity of Cadmium and Roles of Mitigating Agents

    Elias Adikwu

    2013-12-01

    Full Text Available There are increasing reports on cadmium associated hepatotoxicity, due to these reports this study reviewed relevant literature on cadmium associated hepatotoxicity with emphasis on doses, route of administration, salt forms (cadmium compounds and the roles of mitigating agents. Reports have shown that continuous exposure of the liver to cadmium has led to hepatotoxicity. Humans are generally exposed to cadmium by two main routes, inhalation and ingestion. In this study, evaluation of relevant literature showed that irrespective of route of administration and salt forms cadmium hepatotoxicity is dose and time dependent. Cadmium associated hepatotoxicity manifested through impaired functions of hepatic biomarkers (transaminases, enzymatic and non enzymatic antioxidants. Histopathological damage to liver architecture manifested as swelling of hepatocytes, focal necrosis, hepatocytes degeneration, dilatation of ribosomes, damage of membrane-bounded lysosomes, nuclear pyknosis and cytoplasm vacuolization. Deterioration of mitochondrial cristae, deposition of collagen fibrils, hypertrophy of kuffer cells, congestion in central veins and sinusoids, infiltration of mixed inflammatory cells and peripheral hemorrhage also occurred. Hepatotoxic effect of cadmium was mitigated by Vitamin C, Vitamin E, Manganese (11 Chloride, N-acetylcysteine and Selenium. Extracts of plant origin including Solanum tuberosum, Calycopteris floribunda Hibiscus sabdariffa mitigated cadmium induced hepatotoxicity. Chemical substances of animal origin including honey and camel milk were reported to have ameliorated cadmium induced hepatotoxicity. One of the mechanisms of cadmium induced hepatotoxicity is reported to be associated with the up regulation of reactive oxygen species (oxidative stress which caused oxidative damage to lipid contents of membranes and direct liver injury. Conclusion cadmium is dose and time dependently hepatotoxic irrespective of route of administration

  20. Cadmium burden and the risk and phenotype of prostate cancer

    Wu Tony T; Wu Hsi-Chin; Pu Yeong S; Chen Yi-Chun; Lai Ming; Yang Chun Y; Sung Fung-Chang

    2009-01-01

    Abstract Background Studies on the association between prostate cancer and cadmium exposure have yielded conflicting results. This study explored cadmium burden on the risk and phenotype of prostate cancer in men with no evident environmental exposure. Methods Hospital-based 261 prostate cancer cases and 267 controls with benign diseases were recruited from four hospitals in Taiwan. Demographic, dietary and lifestyle data were collected by standardized questionnaires. Blood cadmium (BCd) and ...

  1. Association of Environmental Cadmium Exposure with Pediatric Dental Caries

    Arora, Manish; Weuve, Jennifer Lynn; Schwartz, Joel David; Wright, Robert O.

    2008-01-01

    Background: Although animal experiments have shown that cadmium exposure results in severe dental caries, limited epidemiologic data are available on this issue. Objectives: We aimed to examine the relationship between environmental cadmium exposure and dental caries in children 6–12 years of age. Methods: We analyzed cross-sectional data, including urine cadmium concentrations and counts of decayed or filled tooth surfaces, from the Third National Health and Nutrition Examination Survey. We ...

  2. Extraction-photometric determination of cadmium in meat products

    Krylova, A.N.; Malyarova, M.A.; Zhulenko, V.N.

    1986-06-01

    As a result of industrial discharges, burning of solid and liquid fuels, and recycling of metal scrap, cadmium compounds enter the atmosphere and drop into the water and soil causing contamination. In this paper, a method was developed for determining cadmium in meat products. It involves wet ashing the sample, extractive separation of the cadmium as the diethyldithiocarbamate, reextraction, and determination as cadmium dithizonate or as a complex with 2,2'-dipyridyl. The detection limit with dithizone is 0.005 mg/kg and with 2,2'-dipyridyl 0.05 mg/kg. An analysis is shown to take less than 60 minutes.

  3. Effects of Cadmium on BMP Induced Bone Formation

    陈秋生; 徐顺清

    2003-01-01

    To demonstrate the direct effects of cadmium on activities of bone morphogenetic protein (BMP), a complex containing BMP and cadmium chloride (CdCl2) was implanted beneath the abdominal skin of young male Wistar rats. The activity of BMP was studied by observing the histological changes, and measuring the activity of alkaline phosphatase (ALP) and acid phosphatase (ACP) and calcium content of the implants at different time points. Our results showed that during bone formation induced by BMP, cadmium inhibited the activities of osteoblasts and osteoclasts, and slowed the deposition of calcium. It is concluded that cadmium can directly affect biological activities of BMP directly.

  4. Bioremoval of cadmium by lemna minor in different aquatic conditions

    Uysal, Yagmur [Dept. of Environmental Engineering, Kahramanmaras Sutcu Imam University, Kahramanmaras (Turkey); Taner, Fadime [Dept. of Environmental Engineering, Mersin University, Mersin (Turkey)

    2010-04-15

    This study was undertaken to determine the cadmium removal efficiency of Lemna minor when it was used for treatment of wastewater having different characteristics, i. e., pH, temperature and cadmium concentration. Plants were cultivated in different pH solutions (4.5-8.0) and temperatures (15-35 C) in the presence of cadmium (0.1-10.0 mg/L) for 168 h. The amount of biomass obtained in the study period, the concentrations of cadmium in the tissues and in the media and net uptake of cadmium by Lemna have been determined for each condition. The percentages of cadmium uptake (PMU) and bioconcentration factors (BCF) were also calculated. The highest accumulation was obtained for the highest cadmium concentration of 10.0 mg Cd/L as 11.668 mg Cd/g at pH 6.0, and as 38.650 mg Cd/g at 35 C and pH 5.0. The cadmium accumulation gradually increased with initial concentration of the medium, but the opposite trend was observed for the PMU. However, the maximum PMU was obtained as 52.2% in the solution with the lowest concentration of 0.1 mg Cd/L. A mathematical model was used to describe the cadmium uptake and the equation obtained was seen to fit the experimental data very well. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  5. Kinetic studies of cadmium sulfide precipitation from aqueous thiourea solutions

    Kinetics of cadmium sulfide precipitation by thiourea from aqueous solutions containing ammonia complexes of cadmium(II) under conditions of spontaneous initiation of solid phase within solution volume at temperatures of 298-318 K was studied. It was ascertained that the process activation energy is 77843 J/mol, while the reaction order by initial cadmium complex equals unity. Kinetic equation, which permits control over cadmium sulfide precipitation and preparation of CdS films of desired morphology was derived on the basis of the experimental data

  6. Cadmium elemination from phosphoric acid by ionic flotation

    The ion flotation process for the recovery of cadmium from wet phosphoric acid (30%P2O5) has been studied. This technique combines a chemical recation between the collector and the cadmium to form a precipitate (sublate) which is carried to the surface of the solution by air bubbles. the resulting foam containing the cadmium may then separated from solution. The influence of parameters such as collector and cadmium concentration as well as iron content have been investigated for the case a synthetic acid (30% P2O5). The result have been applied to the industrial phosphoric acid produced from Djebel Onk's phosphates (Algeria)

  7. Cadmium in milk and mammary gland in rats and mice

    The purpose of the present investigation was to study the uptake of cadmium in mammary tissue, effects on milk secretion and composition, and lactational transport of cadmium to the sucklings. Cadmium exposure during lactation resulted in retention of cadmium in the mammary tissue in mice and rats. The uptake of cadmium in the mammary tissue was rapid, as shown in lactating mice by whole-body autoradiography 4 h after an intravenous injection of a tracer dose of 109CdCl2. Retention of cadmium in kidneys of suckling pups was observed in the autoradiograms at 7 days after exposure of the dams. Lactating rats were intravenously infused with 109CdCl2 in 0.9% saline via osmotic minipumps from day 3 to day 16 after parturition. The cadmium dose given was 0, 8.8, 62 and 300 μg Cd/kg body wt. per day. Plasma and milk were collected at day 10 and 16 after parturition. Plasma cadmium levels in dams increased from day 10 to day 16. Cadmium levels were higher in milk than in plasma, with milk/plasma ratios varying from 2 to 6. Zinc levels in milk were positively correlated to cadmium levels in milk (r2=0.26; P=0.03). In milk, 109Cd was distributed in fat (46-52%), casein fraction (40-46%), and whey fraction (6-8%). There was a high correlation between cadmium concentrations in pups' kidney and cadmium concentrations in dam's milk (r2=0.98; P 109Cd was bound to metallothionein in mammary tissue. The fraction of radiolabelled cadmium bound to metallothionein increased in a dose-dependent manner in both the liver (88-98%) and mammary tissue (57-80%). The present results indicate a low transfer of cadmium to the suckling pup, which might be due to binding of cadmium to metallothionein in the mammary tissue. However, during the susceptible developmental period even a low cadmium exposure may be of concern. (orig.)

  8. Phytoremediation of cadmium contaminated soils by tuberose

    The potential of three varieties of tuberose (Prajwal, Shringar and Mexican single) for phytoremediation of soil contaminated with cadmium was evaluated by subjecting the plants to five levels of Cd (0, 25, 50, 75 and 100 mg kg-1 soil). Applied Cd did not produce any toxic symptoms in all the three varieties of tuberose except marginal reduction in the photosynthesis rate and total dry weight beyond 50 mg Cd kg-1 soil. The study showed that tuberose possessed the typical ability of Cd hyper accumulator characterized by (1) accumulation of Cd in the shoots of the plant exceeding the critical judging standard i.e., 100 μg g-1 DW and (2) ratio of Cd in the shoots to bulbs >1. It was concluded that tuberose may be an effective accumulator plant for phytoremediation of cadmium polluted soils. (author)

  9. Prevention of cadmium bioaccumulation by herbal adaptogens

    K Bharavi; A. Gopala Reddy; G S Rao; Ravi Kumar, P.; D Srinivas Kumar; P Prabhu Prasadini

    2011-01-01

    Objectives : To evaluate the effect of various herbal adaptogens such as shade-dried powders of Withania somnifera, Ocimum sanctum, Asperagus recemosus, Andrographis paniculata, Asphaltum panjabinum (Shilajith), Gymnema sylvestre, Spirulina platensis, and Panex ginseng on cadmium (Cd)-induced oxidative stress and its accumulation in broiler chicken. Materials and Methods : A total of 80 male broiler chicks of day old age were randomly assigned to 10 equal groups. Group 1 birds were fed wi...

  10. ELECTROKINETIC REMEDIATION STUDY FOR CADMIUM CONTAMINATED SOIL

    P. Bala Ramudu; R. P. Tiwari; Srivastava, R. K.

    2007-01-01

    This paper presents the results of an experimental research undertaken to evaluate different purging solutions to enhance the removal of cadmium from spiked contaminated field soil by electrokinetic remediation. Three experiments were conducted when soil was saturated with deionised water and subsequently deionised water, ammonium citrate and sodium citrate were used as purging solutions at anode end. One experiment was conducted when the soil was saturated with ammonium citrate and itself wa...

  11. Electron mobility in mercury cadmium telluride

    Patterson, James D.

    1988-01-01

    A previously developed program, which includes all electronic interactions thought to be important, does not correctly predict the value of electron mobility in mercury cadmium telluride particularly near room temperature. Part of the reason for this discrepancy is thought to be the way screening is handled. It seems likely that there are a number of contributors to errors in the calculation. The objective is to survey the calculation, locate reasons for differences between experiment and calculation, and suggest improvements.

  12. Bioaugmentation with cadmium-resistant plant growth-promoting rhizobacteria to assist cadmium phytoextraction by Helianthus annuus.

    Prapagdee, Benjaphorn; Chanprasert, Maesinee; Mongkolsuk, Skorn

    2013-07-01

    Micrococcus sp. MU1 and Klebsiella sp. BAM1, the cadmium-resistant plant growth-promoting rhizobacteria (PGPR), produce high levels of indole-3-acetic acid (IAA) during the late stationary phase of their growth. The ability of PGPR to promote root elongation, plant growth and cadmium uptake in sunflowers (Helianthus annuus) was evaluated. Both species of bacteria were able to remove cadmium ions from an aqueous solution and enhanced cadmium mobilization in contaminated soil. Micrococcus sp. and Klebsiella sp. use aminocyclopropane carboxylic acid as a nitrogen source to support their growth, and the minimum inhibitory concentrations of cadmium for Micrococcus sp. and Klebsiella sp. were 1000 and 800mM, respectively. These bacteria promoted root elongation in H. annuus seedlings in both the absence and presence of cadmium compared to uninoculated seedlings. Inoculation with these bacteria was found to increase the root lengths of H. annuus that had been planted in cadmium-contaminated soil. An increase in dry weight was observed for H. annuus inoculated with Micrococcus sp. Moreover, Micrococcus sp. enhanced the accumulation of cadmium in the root and leaf of H. annuus compared to untreated plants. The highest cadmium accumulation in the whole plant was observed when the plants were treated with EDTA following the treatment with Micrococcus sp. In addition, the highest translocation of cadmium from root to the above-ground tissues of H. annuus was found after treatment with Klebsiella sp. in the fourth week after planting. Our results show that plant growth and cadmium accumulation in H. annuus was significantly enhanced by cadmium-resistant PGPRs, and these bacterial inoculants are excellent promoters of phytoextraction for the rehabilitation of heavy metal-polluted environments. PMID:23478127

  13. Bioavailability of cadmium from linseed and cocoa

    Hansen, Max; Rasmussen, Rie Romme; Sloth, Jens Jørgen

    2014-01-01

    the food authorities in order to give correct advises to the population. The aim of this study was to investigate the bioavailability of cadmium from whole linseed, crushed linseed, cocoa and cadmium chloride in rats. An experiment where 40 rats were divided into 4 groups and a control group and dosed...... with whole linseed, crushed linseed, cocoa and CdCl2 for 3 weeks was performed. Linseed or cocoa made up 10% of the feed (by weight) and was added as a replacement for carbohydrate source. The rats were dosed for 3 weeks and the cadmium content in the rats' kidneys was measured by ICPMS as a biomarker...... which could be measured in the kidney compared to the calculated total intake was as follows: Control 2.0 %, Crushed linseed 0.9 %, whole linseed, 1.5 %, cocoa 0.7 % and CdCl2 4.6 %. Based on this study it could not be concluded that the bioavailability in rats form whole linseed is lower that for...

  14. Soil ecotoxicity assessment using cadmium sensitive plants

    The crop plants, sorghum and cucumber, can be used as indicator species to assess ecotoxicity of soils contaminated by cadmium. - Four crop plant species (sweet corn, Zea may; wheat, Triticum aestivum; cucumber, Cucumis sativus; and sorghum, Sorghum bicolor) were tested to assess an ecotoxicity in cadmium-amended soils. The measurement endpoints used were seed germination and seedling growth (shoot and root). The presence of cadmium decreased the seedling growth. The medium effective concentration values (EC50) for shoot or root growth were calculated by the Trimmed Spearman-Karber method. Due to the greater accumulation of Cd to the roots, root growth was a more sensitive endpoint than shoot growth. Bioavailability and transport of Cd within plant were related to concentration and species. The ratio of bioaccumulation factor (BAF) in the shoots to the roots indicated high immobilization of Cd in the roots. Seed germination was insensitive to Cd toxicity, and is not recommended for a suitable assay. Among the test plants and test endpoints, root growth of sorghum and cucumber appears to be a good protocol to assess ecotoxicity of soils contaminated by Cd

  15. Soil ecotoxicity assessment using cadmium sensitive plants

    An, Youn-Joo

    2004-01-01

    The crop plants, sorghum and cucumber, can be used as indicator species to assess ecotoxicity of soils contaminated by cadmium. - Four crop plant species (sweet corn, Zea may; wheat, Triticum aestivum; cucumber, Cucumis sativus; and sorghum, Sorghum bicolor) were tested to assess an ecotoxicity in cadmium-amended soils. The measurement endpoints used were seed germination and seedling growth (shoot and root). The presence of cadmium decreased the seedling growth. The medium effective concentration values (EC50) for shoot or root growth were calculated by the Trimmed Spearman-Karber method. Due to the greater accumulation of Cd to the roots, root growth was a more sensitive endpoint than shoot growth. Bioavailability and transport of Cd within plant were related to concentration and species. The ratio of bioaccumulation factor (BAF) in the shoots to the roots indicated high immobilization of Cd in the roots. Seed germination was insensitive to Cd toxicity, and is not recommended for a suitable assay. Among the test plants and test endpoints, root growth of sorghum and cucumber appears to be a good protocol to assess ecotoxicity of soils contaminated by Cd.

  16. OXIDATIVE STRESS IN SHEEP INDUCED BY CADMIUM CHLORIDE TOXICITY, WITH THERAPEUTIC EFFECTS OF ALPHA LIPOIC ACID

    Hussien Ali NAJI

    2015-09-01

    Full Text Available Cadmium (Cd is a heavy toxic metal, with harmful effects on animals and public health. Recently the risk of cadmium toxicity is substantially regarded; the environmental pollution is increased due to multi- uses of this element in various industries. This study was performed to clarify the effects of acute cadmium toxicity in sheep with trail of using alpha lipoic acid as an antioxidant therapeutic substance. Fifteen male lambs aged from 5-to-7 months were divided equally in to three groups, they were supplied with ordinary diet and provided with water ad-lib, the first group 1 was administered a single dose of CdCl2 3 mg/kg.bw subcutaneously (S/C, the second group 2 was injected with the same dose of CdCl2 and by the same route, and then simultaneously administered an alpha lipoic acid 50 mg/kg.bw intramuscularly, the later drug was repeated after 12 hours via the same route. The third group 3 was left as control and given normal saline (S/C. All animals were daily monitored and the clinical signs were recorded. The signs of cadmium toxicity appeared 18 hours post CdCl2 administration in the group 1; the signs were gradually increased in severity and multiple systems were involved included: digestive disturbances, cardiovascular and neurological dysfunctions, and locomotors abnormalities. Significant elevations in the body temperature, respiratory and heart rates were observed, deaths of 2 lambs were recorded 96 hours post CdCl2 injection. The group 2 showed mild clinical signs, and no death was occurred, moreover insignificant variations between clinical parameters in both groups 2 and 3 were recorded. Serum biochemical analysis revealed significant (P<0.05 increased of malondialdehyde (5.41 ± 0.282 μmol/L and glutathione (10.68 ± 0.38 μmol/L concentrations and marked elevation of serum catalase activity (103.85 ± 3.93 u/L was also observed in group I, whereas the last three parameters showed no significant differences between groups 2

  17. Use of cadmium in solution in the EL 4 reactor moderator irreversible fixing of cadmium on the metallic surfaces

    In the framework of research into the poisoning of the EL-4 reactor by cadmium sulphate, measurements have been made by two different methods of the residual amounts of cadmium liable to be fixed irreversibly on the surfaces in contact with the heavy water. A marked influence of the pH has been noticed. The mechanism of the irreversible fixing is compatible with the hypothesis of an ion-exchange in the surface oxide layer. In a sufficiently wide range of pH the cadmium thus fixed causes very little residual poisoning. The stability of the cadmium sulphate solutions is however rather low in the conditions of poisoning. (authors)

  18. Reduction of Cadmium Uptake of Rice Plants Using Soil Amendments in High Cadmium Contaminated Soil: A Pot Experiment

    Dian Siswanto; Parinda Suksabye; Paitip Thiravetyan

    2013-01-01

    The aims of this study were to investigate the effect of agricultural residues on reducing cadmium uptake in rice plants. The rice plants growing on no cadmium/free cadmium soils (N), Cd soils (Cds), and Cd soils each amended with 1% w/w of coir pith (CP), coir pith modified with sodium hydroxide (CPm) and corncob (CC) under high cadmium contaminated soil with an average 145 mg Cd kg-1 soil were investigated. The results showed that the cumulative transpiration of rice grown in various treatm...

  19. Cardiac Autonomic Effects of Acute Exposures to Airborne Particulates in Men and Women

    Howarth, M. S.; Schlegel, T. T.; Knapp, C. F.; Patwardhan, A. R.; Jenkins, R. A.; Ilgner, R. H.; Evans, J. M.

    2007-01-01

    The aim of this research was to investigate cardiac autonomic changes associated with acute exposures to airborne particulates. Methods: High fidelity 12-lead ECG (CardioSoft, Houston, TX) was acquired from 19 (10 male / 9 female) non-smoking volunteers (age 33.6 +/- 6.6 yrs) during 10 minutes pre-exposure, exposure and post-exposure to environmental tobacco smoke (ETS), cooking oil fumes, wood smoke and sham (water vapor). To control exposure levels, noise, subject activity, and temperature, all studies were conducted inside an environmental chamber. Results: The short-term fractal scaling exponent (Alpha-1) and the ratio of low frequency to high frequency Heart Rate Variability (HRV) powers (LF/HF, a purported sympathetic index) were both higher in males (pcardiac responses to some acute airborne particulates are gender related.

  20. Cadmium sulfate complexing with thiourea during preparation of cadmium sulfide films

    Composition of complexes deposited from cadmium sulfate and thiourea(TU) aqueous solution is studied. Its influence on cadmium sulfide film deposition during solution spraying is ascertained. It is shown that with increase of TU concentration in aqueous solution gradual substitution of TU molecules for the first sphere SO42- ions takes place. As a result CdS deposition from these solutions is initiated when the ratio of CdSO4:TU concentrations is 1:2 and for prepartation of uniform films a five-fold TU excess as a minimum is necessary

  1. Escaping the Tyranny of Carbothermal Reduction: Fumed Silica from Sustainable, Green Sources without First Having to Make SiCl4.

    Yi, Eongyu; Hyde, Clare E; Sun, Kai; Laine, Richard M

    2016-02-12

    Fumed silica is produced in 1000 tons per year quantities by combusting SiCl4 in H2 /O2 flames. Given that both SiCl4 and combustion byproduct HCl are corrosive, toxic and polluting, this route to fumed silica requires extensive safeguards that may be obviated if an alternate route were found. Silica, including rice hull ash (RHA) can be directly depolymerized using hindered diols to generate distillable spirocyclic alkoxysilanes or Si(OEt)4 . We report here the use of liquid-feed flame spray pyrolysis (LF-FSP) to combust the aforementioned precursors to produce fumed silica very similar to SiCl4 -derived products. The resulting powders are amorphous, necked, <50 nm average particle sizes, with specific surface areas (SSAs) of 140-230 m(2)  g(-1) . The LF-FSP approach does not require the containment constraints of the SiCl4 process and given that the RHA silica source is produced in million ton per year quantities worldwide, the reported approach represents a sustainable, green and potentially lower-cost alternative. PMID:26699804

  2. Correlative characteristic of cadmium in soils of steppe Dnieper region

    N. M. Tsvetkova

    2015-09-01

    Full Text Available Much attention is paid to searching for methods of establishing environmental standards for objective assessment of admissibility of anthropogenic load on the biosphere. The main pollutants of the environment are xenobiotics; heavy metals such as cadmium occupy hold a special place among them. Cadmium is one of the most dangerous environmental toxic agents, belonging to the 1stclass of hazard. Due to insufficient and fragmented information available on the distribution of cadmium in the city edaphotopes, it’s necessary to conduct additional research, taking into account the properties of soils and the biological characteristics of every element. The paper shows the ratio of cadmium in soils and soil-forming rocks of steppe Dnieper region. Environmental assessment of cadmium content in Dniprodzerzhinsk city soilsis made, and the problem of topsoil contamination of the city as a territory of high anthropogenic load is considered. It is found that the content of cadmium down the profile in natural soil increases. Enrichment of the topsoil with cadmium occurs due to contamination. The value of movable forms content, expressed as a percentage of the total content, varies from 12% to 70%, providing the evidence of the technogenic origin of cadmium in Dniprodzerzhinsk city topsoil. General and proximate correlation analyses of interrelation of soil cadmium and specifically selected characteristics of soil (pH, humus, sulfate ions, dry solid, chloride ions, total alkalinity, hygroscopic moisture were made. It is established that cadmium concentration in the movable forms of natural soils of the steppe Dnieper region depends primarily on pH value. With the increase in pH value, concentration of movable cadmium in soil increases.

  3. Critical review of animal carcinogenesis by cadmium and its inorganic compounds

    Animal carcinogenic biassays relative to 6 inorganic cadmium substances (cadmium metal, cadmium oxide, cadmium sulfide, cadmium sulfate, cadmium chloride and cadmium acetate) are reviewed (speciation). Critical evaluation of literature data on carcinogenicity has been performed by making reference to E.C. guidelines of good laboratory practice. There are few data on routes relevant for human risk assessment: experiments on inhalation demonstrate lung carcinogenicity of cadmium oxide, cadmium sulfide, cadmium sulfate and cadmium chloride in rats but not in mice nor in hamsters; no carcinogenic effects of cadmium compounds are observed following oral administration. For routes of less or no relevance for human risk assessment, some results are clearly positive: subcutaneous injection induces cancers in situ (various cadmium compounds), testicular tumours (cadmium sulfate and cadmium chloride) and prostatic tumours (cadmium chloride) but such effects are not observed using relevant malignancies in rats. With respect to other no relevant routes (intraperitoneal, intrarenal...) tumours are incidentally produced in situ, but not in remote organs. Numerous studies fail to demonstrate cadmium carcinogenicity, but methodologically acceptable negative ones are very limited in number. Accordingly strain dependent effects and dose effect relationship could not be thoroughly assessed

  4. Acute pancreatitis

    Al Mofleh Ibrahim

    1997-01-01

    Full Text Available The past few years have witnessed a tremendous progress in our knowledge regarding the pathogenesis, diagnosis, prognostic evaluation and classification of acute pancreatitis. The role of ischemia, lysosomal enzymes, oxygen free radicals, polymorphnuclear cells-byproducts and inflammatory mediators in the pathogenesis of pancreatic necrosis and multiple organ failure has been emphasized. Furthermore, the recent knowledge about agents infecting pancreatic necrosis, routes of infection, bacteriological examination of fine needle aspirate and appropriate antibiotics have changed the concept of acute pancreatitis. New diagnostic tests such as rapid urinary trypsinogen-2 test and inflammatory mediators including polymorphnuclear elastase, C-reactive protein and interleukin-6 contribute to early diagnosis, prognostic evaluation and initiation of an appropriate therapy.

  5. Effect of cadmium on glutathione S-transferase and metallothionein gene expression in coho salmon liver, gill and olfactory tissues

    Highlights: ► Developed qPCR assays to distinguish closely related GST isoforms in salmon. ► Examined the effect of cadmium on GST and metallothionein genes in 3 tissues. ► Modulation of GST varied among isoforms, tissues, and included a loss of expression. ► Metallothionein outperformed, but generally complemented, GSTs as biomarkers. ► Salmon olfactory genes were among the most responsive to cadmium. - Abstract: The glutathione S-transferases (GSTs) are a multifunctional family of phase II enzymes that detoxify a variety of environmental chemicals, reactive intermediates, and secondary products of oxidative damage. GST mRNA expression and catalytic activity have been used as biomarkers of exposure to environmental chemicals. However, factors such as species differences in induction, partial analyses of multiple GST isoforms, and lack of understanding of fish GST gene regulation, have confounded the use of GSTs as markers of pollutant exposure. In the present study, we examined the effect of exposure to cadmium (Cd), a prototypical environmental contaminant and inducer of mammalian GST, on GST mRNA expression in coho salmon (Oncorhynchus kisutch) liver, gill, and olfactory tissues. GST expression data were compared to those for metallothionein (MT), a prototypical biomarker of metal exposure. Data mining of genomic databases led to the development of quantitative real-time PCR (qPCR) assays for salmon GST isoforms encompassing 9 subfamilies, including alpha, mu, pi, theta, omega, kappa, rho, zeta and microsomal GST. In vivo acute (8–48 h) exposures to low (3.7 ppb) and high (347 ppb) levels of Cd relevant to environmental scenarios elicited a variety of transient, albeit minor changes (<2.5-fold) in tissue GST profiles, including some reductions in GST mRNA expression. In general, olfactory GSTs were the earliest to respond to cadmium, whereas, more pronounced effects in olfactory and gill GST expression were observed at 48 h relative to earlier time

  6. Effect of cadmium on glutathione S-transferase and metallothionein gene expression in coho salmon liver, gill and olfactory tissues

    Espinoza, Herbert M.; Williams, Chase R. [Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98105-6099 (United States); Gallagher, Evan P., E-mail: evang3@u.washington.edu [Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98105-6099 (United States)

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Developed qPCR assays to distinguish closely related GST isoforms in salmon. Black-Right-Pointing-Pointer Examined the effect of cadmium on GST and metallothionein genes in 3 tissues. Black-Right-Pointing-Pointer Modulation of GST varied among isoforms, tissues, and included a loss of expression. Black-Right-Pointing-Pointer Metallothionein outperformed, but generally complemented, GSTs as biomarkers. Black-Right-Pointing-Pointer Salmon olfactory genes were among the most responsive to cadmium. - Abstract: The glutathione S-transferases (GSTs) are a multifunctional family of phase II enzymes that detoxify a variety of environmental chemicals, reactive intermediates, and secondary products of oxidative damage. GST mRNA expression and catalytic activity have been used as biomarkers of exposure to environmental chemicals. However, factors such as species differences in induction, partial analyses of multiple GST isoforms, and lack of understanding of fish GST gene regulation, have confounded the use of GSTs as markers of pollutant exposure. In the present study, we examined the effect of exposure to cadmium (Cd), a prototypical environmental contaminant and inducer of mammalian GST, on GST mRNA expression in coho salmon (Oncorhynchus kisutch) liver, gill, and olfactory tissues. GST expression data were compared to those for metallothionein (MT), a prototypical biomarker of metal exposure. Data mining of genomic databases led to the development of quantitative real-time PCR (qPCR) assays for salmon GST isoforms encompassing 9 subfamilies, including alpha, mu, pi, theta, omega, kappa, rho, zeta and microsomal GST. In vivo acute (8-48 h) exposures to low (3.7 ppb) and high (347 ppb) levels of Cd relevant to environmental scenarios elicited a variety of transient, albeit minor changes (<2.5-fold) in tissue GST profiles, including some reductions in GST mRNA expression. In general, olfactory GSTs were the earliest to respond to

  7. Effects of Aluminium Sulfate on Cadmium Accumulation in Rice

    Full text: Cadmium accumulation in Pathum Thani 1 and Suphan Buri 60 rice cultivars was investigated upon treatment with aluminium sulfate as a precipitant. Rice was grown hydroponically in a medium containing 4 ppm cadmium nitrate with or without 4 ppm aluminium sulfate. Root, stem with leaves and grain samples were collected and analyzed for cadmium content using atomic absorption spectroscopy and inductively coupled plasma atomic emission spectroscopy. Without the addition of aluminium sulfate, Pathum Thani 1 and Suphan Buri 60 accumulated 24.71∫ 3.14 ppm and 34.43 ∫ 4.51 ppm (dry weight of whole plant) of cadmium, respectively. With aluminium sulfate, cadmium accumulation increased to 40.66 ∫ 2.47 ppm and 62.94 ∫ 10.69 ppm, respectively. The addition of aluminium sulfate to the planting medium did not reduce cadmium accumulation but caused the rice to accumulate more cadmium especially in the shoots and grains. This observation might serve as the basis for future research on the management of agricultural areas that are contaminated with cadmium and aluminium

  8. Phytoremediation of cadmium and nickel by Spirodela polyrhiza

    Heavy metal pollution in surface and groundwater has considerably increased in the last few years. It is essential to have an effective removal mechanism of these toxic metals. Current research includes the need to develop environment friendly and cost effective technologies for removing heavy metals from water. In several studies cadmium and nickel have been considerably removed using phytoremediation. The removal efficiency of cadmium and nickel by Spirodela polyrhiza, common duckweed has been examined in the present study for 3 different concentrations of cadmium (1, 2 and 3 mg/L) and nickel (4, 5 and 6 mg/L). Two sets of experiments for cadmium and nickel were conducted separately. Effect of metal toxicity on Spirodela polyrhiza was evaluated in terms of relative growth factor and cadmium was found to be more toxic than nickel. Under experimental condition BCF value for cadmium removal was more than >1000 in all the 3 concentrations of cadmium. But the BCF value was found to be more than > 1000 only when input nickel concentration was 4 mg/L during phytoremediation process. Experimental results suggest that Spirodela polyrhiza has the potential of accumulating cadmium and nickel from aqueous solution at lower metal concentration. (author)

  9. Cadmium inhibits neurogenesis in zebrafish embryonic brain development

    Chow, Elly Suk Hen [Division of Biology, California Institute of Technology, 1200 California Boulevard, Pasadena, CA 91125 (United States); Hui, Michelle Nga Yu; Lin Chunchi [Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China); Cheng Shukhan [Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China)], E-mail: bhcheng@cityu.edu.hk

    2008-05-01

    Cadmium is a non-essential heavy metal found abundantly in the environment. Children of women exposed to cadmium during pregnancy display lower motor and perceptual abilities. High cadmium body burden in children is also related to impaired intelligence and lowered school achievement. However, little is known about the molecular and cellular basis of developmental neurotoxicity in the sensitive early life stages of animals. In this study, we explore neurological deficits caused by cadmium during early embryonic stages in zebrafish by examining regionalization of the neural tube, pattern formation and cell fate determination, commitment of proneural genes and induction of neurogenesis. We show that cadmium-treated embryos developed a smaller head with unclear boundaries between the brain subdivisions, particularly in the mid-hindbrain region. Embryos display normal anterior to posterior regionalization; however, the commitment of neural progenitor cells was affected by cadmium. We observe prominent reductions in the expression of several proneuronal genes including ngn1 in cell clusters, zash1a in the developing optic tectum, and zash1b in the telencephalon and tectum. Cadmium-treated embryos also have fewer differentiated neurons and glia in the facial sensory ganglia as indicated by decreased zn-12 expression. Also, a lower transcription level of neurogenic genes, ngn1 and neuroD, is observed in neurons. Our data suggest that cadmium-induced neurotoxicity can be caused by impaired neurogenesis, resulting in markedly reduced neuronal differentiation and axonogenesis.

  10. Epigenetic Effects of Cadmium [Abstract and Poster 2014

    We have reviewed the literature on in vitro and in vivo experiments as well as human studies on cadmium to understand the epigenetic mechanisms involved in cadmium- induced toxicity and carcinogenicity. This presentation will identify gaps in our current understanding and suggest...

  11. Removing cadmium from electroplating wastewater by waste saccharomyces cerevisiae

    DAI Shu-juan; WEI De-zhou; ZHOU Dong-qin; JIA Chun-yun; WANG Yu-juan; LIU Wen-gang

    2008-01-01

    The appropriate condition and scheme of removing cadmium from electroplating wastewater were investigated by adsorption-precipitation method using waste saccharomyces cerevisiae(WSC) as sorbent. Effect factors on biosorption of cadmium in cadmium-containing electroplating wastewater by waste saccharomyces cerevisiae and precipitation process of waste saccharomyces cerevisiae after adsorbing cadmium were studied. The results show that removal rate of cadmium is over 88% after 30 min adsorbing under the condition of cadmium concentration 26 mg/L, the dosage of waste saccharomyces cerevisiae 16.25 g/L, temperature 18 ℃, pH 6.0 and precipitation time 4 h. Biosorption-precipitation method is effective to remove cadmium in cadmium-containing electroplating wastewater by waste saccharomyces cerevisiae. The SEM, infrared spectroscopy and Zeta-potential of the cells show that chemical chelating is the main adsorption form; electrostatic attraction, hydrogen bonding and van der Waals force all function in adsorption process; and ―NH2―,―C=O―,―C=O―NH―,―CH3, ―OH are the main adsorption groups.

  12. Method of making a thin film cadmium telluride solar cell

    A method for making a photovoltaic cell is described comprising the steps of: (a) depositing a transparent or semi-transparent conductive window layer onto a substrate; (b) depositing a layer of cadmium telluride including phosphorus onto the window layer; (c) depositing a layer of lead telluride onto the layer of cadmium telluride; and (d) depositing a metallic electrode onto the lead telluride layer

  13. Effect of environmental exposure to Cadmium on pregnancy outcome

    F. Ramezanzadeh

    2010-04-01

    Full Text Available "n "n "nBackgrounds andObjectives:The objective of the present study was to evaluate the potential effect of environmental exposure to toxic metal (cadmium on pregnancy outcome and fetal growth."nMaterials and Methods: 330 normal pregnant women were randomly selected from vali-e-asr hospital, from July 2003 through Feb. 2005. Cadmium was measured in umbilical cord blood and mother whole blood of postpartum women without occupational exposure to metals in Tehran, Iran, using inductively coupled plasma mass spectrometry"nResult: Whole blood cadmium and cord blood cadmium ranged from 0/00 to 6/30 μg/L ,respectivly. in the group higher level of maternal blood cadmium (> 0.40 μg/L 1cm decrease was seen in neonatal birth height. (p = 0.007 There was a significant association between cadmium exposure and birth weight.Mann-whitney test showed that, maternal blood cadmium level, was significantly negatively associated with neonatal birth weight (z = -1.83, P < 0.06."nConclusion: It was concluded that environmental exposure to cadmium significantly reduces neonatal birth height.

  14. Risk of overestimation of urinary cadmium concentrations: interference from molybdenum

    Cañas A.I.

    2013-04-01

    Full Text Available We show here that the selection of analytical method is critical when measuring low levels of cadmium in human urine. Cadmium is today usually analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS, which has a higher sensitivity than Atomic Absorption Spectroscopy (AAS. ICP-MS cadmium measurements show interference from tin (114Sn and molybdenum oxides, which can result in an overestimation of cadmium levels. The 114Sn interference is stable and can be mathematically corrected. Molybdenum concentrations in urine are variable and different from individual to individual. We have estimated the degree of error which molybdenum interference introduces in the measurement of cadmium in urine by conventional ICP-MS. 268 urine samples from mothers and their children were measured. Removal of the molybdenum oxide interference (DRC-ICP-MS method reduced urinary cadmium concentrations significantly (47.8%. The urinary molybdenum concentration in children was higher than in their mothers, resulting in greater overestimation. Our results clearly show that the DRC method is essential for reliable measurements of urinary cadmium concentrations, particularly in children. Furthermore, care should be taken when comparing Human Biomonitoring data for cadmium in urine and attention should be paid to which analytical method has been used (e.g. AAS and ICP-Ms, and especially if the measurements have been corrected for molybdenum interference.

  15. Electrolytic indium refining from cadmium in glycerine electrolyte

    The results of investigations directed on development of electrochemical indium cleaning from cadmium in glycerine base electrolyte are presented. Optimal operational conditions, specific consumption of reactants and electric power are determined. Relationship between variation of concentration of cadmium impurity in refined metal and duration of electrolysis is revealed. The method for determination of cleaning time is proposed. Developed process was put into commercial operation

  16. Cadmium inhibits neurogenesis in zebrafish embryonic brain development

    Cadmium is a non-essential heavy metal found abundantly in the environment. Children of women exposed to cadmium during pregnancy display lower motor and perceptual abilities. High cadmium body burden in children is also related to impaired intelligence and lowered school achievement. However, little is known about the molecular and cellular basis of developmental neurotoxicity in the sensitive early life stages of animals. In this study, we explore neurological deficits caused by cadmium during early embryonic stages in zebrafish by examining regionalization of the neural tube, pattern formation and cell fate determination, commitment of proneural genes and induction of neurogenesis. We show that cadmium-treated embryos developed a smaller head with unclear boundaries between the brain subdivisions, particularly in the mid-hindbrain region. Embryos display normal anterior to posterior regionalization; however, the commitment of neural progenitor cells was affected by cadmium. We observe prominent reductions in the expression of several proneuronal genes including ngn1 in cell clusters, zash1a in the developing optic tectum, and zash1b in the telencephalon and tectum. Cadmium-treated embryos also have fewer differentiated neurons and glia in the facial sensory ganglia as indicated by decreased zn-12 expression. Also, a lower transcription level of neurogenic genes, ngn1 and neuroD, is observed in neurons. Our data suggest that cadmium-induced neurotoxicity can be caused by impaired neurogenesis, resulting in markedly reduced neuronal differentiation and axonogenesis

  17. Cadmium Removal from Aqueous Solutions by Ground Pine Cone

    H Izanloo, S Nasseri

    2005-01-01

    Full Text Available A study on the removal of cadmium ions from aqueous solutions by pine cone was conducted in batch conditions. Kinetic data and equilibrium removal isotherms were obtained. The influence of different experimental parameters such as contact time, initial concentration of cadmium, pine cone mass and particle size, and temperature on the kinetics of cadmium removal was studied. Results showed that the main parameters that played an important role in removal phenomenon were initial cadmium concentration, particle size and pine cone mass. The necessary time to reach equilibrium was between 4 and 7 hours based on the initial concentration of cadmium. The capacity of cadmium adsorption at equilibrium increased with the decrease of pine cone particle size. The capacity of cadmium adsorption at equilibrium by pine cone increased with the quantity of pine cone introduced (1–4 g/L. Temperature in the range of 20-30°C showed a restricted effect on the removal kinetics (13.56 mg/g at 20°C and a low capacity of adsorption about 11.48 mg/g at 30°C. The process followed pseudo second-order kinetics. The cadmium uptake of pine cone was quantitatively evaluated using adsorption isotherms. Results indicated that the Langmuir model gave a better fit to the experimental data in comparison with the Freundlich equation.

  18. Study on the development trends of movable welding fume purifier%移动式焊烟净化机的发展方向

    陈伟馨; 蒋安邦; 欧朝旭; 周家权; 邬思丹

    2012-01-01

    当前国内外都大力倡导局部净化为主、全面通风为辅的通风系统原则.但局部净化的主要设备——移动式焊烟净化机靠手工移动吸尘罩来进行吸尘,已经不能满足大工件、长焊缝的净化要求,而且净化机存在吸尘空间小、吸尘效率不高的问题.通过有限元法分析出吸尘罩吸尘效率的分布情况,并研发了焊接烟尘自动跟踪臂.在焊接烟尘自动跟踪臂工作过程中,它会带着吸尘罩紧跟焊接点,始终在吸尘效率的最佳区域工作.既提高了净化机的吸尘效率,净化了工作环境,又提高了焊接劳动生产率.%It reached a consensus that welding fume is environmental hazard.So all the world attaches great importance to the purification of weld fumes.The principle of ventilation systems that mainly conducted in partial purification and supplemented with full ventilation are advocated vigorously in the world.The main equipment of partial purification-welding fume purifier sucks fumes by moveable dust shield manually,that are inefficient for long welding seam or large workpieces.At the same time,it faced with many other problems, such as little working space, low efficiency .Through the finite element analysis method, to analyze on the cleaning efficiency distribution of dust shield,this study developed robotic arm that could intelligently track the welding sparks and always work in the best area of dust-removing efficiency called welding smoke tracking robot.lt help to improve the efficiency for dust cleaning of movable welding fume purifier and labour productivity.

  19. Interaction between Polymorphisms in Pre-MiRNA Genes and Cooking Oil Fume Exposure on the Risk of Lung Cancer in Chinese Non-Smoking Female Population.

    Zhihua Yin

    Full Text Available Both genetic polymorphisms and environmental risk factors play important roles in the development of human chronic diseases including lung cancer. This is the first case-control study of interaction between polymorphisms in pre-miRNA genes and cooking oil fume exposure on the risk of lung cancer.A hospital-based case-control study of 258 cases and 310 controls was conducted. Six polymorphisms in miRNAs were determined by Taqman allelic discrimination method. The gene-environment interactions were assessed on both additive and multiplicative scale. The statistical analyses were performed mostly with SPSS.The combination of the risk genotypes of five miRNA SNPs (miR-146a rs2910164, miR-196a2 rs11614913, miR-608 rs4919510, miR-27a rs895819 and miR-423 rs6505162 with risk factor (cooking oil fume exposure contributed to a significantly higher risk of lung cancer, and the corresponding ORs (95% confidence intervals were 1.91(1.04-3.52, 1.94 (1.16-3.25, 2.06 (1.22-3.49, 1.76 (1.03-2.98 and 2.13 (1.29-3.51. The individuals with both risk genotypes of miRNA SNPs and exposure to risk factor (cooking oil fumes were in a higher risk of lung cancer than persons with only one of the two risk factors (ORs were 1.91, 1.05 and 1.41 for miR-146a rs2910164, ORs were 1.94, 1.23 and 1.34 for miR-196a2 rs11614913, ORs were 2.06, 1.41 and 1.68 for miR-608 rs4919510, ORs were 1.76, 0.82 and 1.07 for miR-27a rs895819, and ORs were 2.13, 1.15 and 1.02 for miR-423 rs6505162, respectively. All the measures of biological interaction indicate that there were not indeed biological interactions between the six SNPs of miRNAs and exposure to cooking oil fumes on an additive scale. Logistic models suggested that the gene-environment interactions were not statistically significant on a multiplicative scale.The interactions between miRNA SNPs and cooking oil fume exposure suggested by ORs of different combination were not statistically significant.

  20. Development of nanocomposite based on hydroxyethylmethacrylate and functionalized fumed silica: mechanical, chemico-physical and biological characterization.

    D'Agostino, Antonella; Errico, Maria Emanuela; Malinconico, Mario; De Rosa, Mario; Avella, Maurizio; Schiraldi, Chiara

    2011-03-01

    In this research work organic/inorganic nano composites were synthesized from poly-2-hydroxyethylmethacrylate and properly modified silica nanoparticles by in situ polymerization. In particular, fumed nanosilica was functionalized with methacryloylpropyltrimetoxy silane (MPTMS) in order to obtain a more homogeneous, reliable and mechanically performing nano composite. For comparison, nano composites with non functionalized silica were also prepared. Scanning electron microscopy was performed in order to visualize the effects of functionalization on the mode and state of dispersion. This analysis demonstrated that MPTMS grafted onto silica surface acts as an effective coupling agent and assures a good dispersion and distribution of nanoparticles as well as a strong nano particle/matrix interfacial adhesion. As a result of strong interactions occurring between phases, a pronounced increase of the glass transition temperature and mechanical parameters were recorded. Finally, these novel nano composites were seeded with murine fibroblast and human mesenchymal stem cells, and observed in time-lapse experiments proving an effective biological response. PMID:21221729

  1. Shrinkage and Cracking Sensitivity of Cement Mortar Containing Fly Ash, Granulated Blast-furnace Slag and Silica Fume

    2006-01-01

    A laboratory study was undertaken to investigate drying shrinkage and cracking sensitivity subjected to restrained shrinkage of mortar containing fly ash (FA), granulated blast-furnace slag (GBFS) and silica fume (SF). Six mortar mixtures including control Portland cement (PC) and FA,GBFS and SF mortar mixtures were prepared. FA replaced the cement on mass basis at the replacement ratios of 20% and 35%, GBFS replaced the cement at the replacement ratios of 40%, SF replaced the cement at the replacement ratios of 8% and the blended mixtures with 20% FA, 20% GBFS and 8% SF. Water-cementitious materials ratio and sand-cementitious materials ratio were 0.4 and 2.0 for all mixtures, respectively. The mixtures were cured at 65% relative humidity and 20℃. The drying shrinkage value, initial cracking time and cracking width of the mortar samples were measured. The results show that all the mortar mixture containing FA exhibited the decrease of drying shrinkage.Moreover, initial cracking time was markedly delayed, and the crack width of the initial crack was reduced. However, the incorporations of various ratios of GBFS and SF led to an increase of drying shrinkage, initial cracking time and cracking width as compared to control mixture.

  2. Integration of chemical scrubber with sodium hypochlorite and surfactant for removal of hydrocarbons in cooking oil fume

    There are many types of technologies to control cooking oil fumes (COFs), but current typical technologies, such as electrostatic precipitator, conventional scrubber, catalyst, or condenser, are unable to efficiently remove the odorous materials present in COFs which are the primary cause of odor-complaint cases. There is also a lack of information about using sodium hypochlorite (NaOCl) and surfactants to remove contaminants in COFs, and previous studies lack on-site investigations in restaurants. This study presents a chemical scrubber integrated with an automatic control system (ACS) to treat hydrocarbons (HCs) in COFs, and to monitor non-methane HCs (NMHC) and odor as indicators for its efficiency evaluation. The chemical scrubber effectively treats hydrophobic substances in COFs by combining surfactant and NaOCl under optimal operational conditions with NHMC removal efficiency as high as 85%. The mass transfer coefficient (KLa) of NMHC was enhanced by 50% under the NaOCl and surfactant conditions, as compared to typical wet scrubber. Further, this study establishes the fuzzy equations of the ACS, including the relationship between the removal efficiency and KLa, liquid/gas ratio, pH and CNaOCl.

  3. Integration of chemical scrubber with sodium hypochlorite and surfactant for removal of hydrocarbons in cooking oil fume

    Cheng, Hsin-Han [Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology, Touliu, Yunlin, Taiwan (China); Hsieh, Chu-Chin, E-mail: hsiehcc@yuntech.edu.tw [Department of Environmental and Safety Engineering, National Yunlin University of Science and Technology, Touliu, Yunlin, Taiwan (China)

    2010-10-15

    There are many types of technologies to control cooking oil fumes (COFs), but current typical technologies, such as electrostatic precipitator, conventional scrubber, catalyst, or condenser, are unable to efficiently remove the odorous materials present in COFs which are the primary cause of odor-complaint cases. There is also a lack of information about using sodium hypochlorite (NaOCl) and surfactants to remove contaminants in COFs, and previous studies lack on-site investigations in restaurants. This study presents a chemical scrubber integrated with an automatic control system (ACS) to treat hydrocarbons (HCs) in COFs, and to monitor non-methane HCs (NMHC) and odor as indicators for its efficiency evaluation. The chemical scrubber effectively treats hydrophobic substances in COFs by combining surfactant and NaOCl under optimal operational conditions with NHMC removal efficiency as high as 85%. The mass transfer coefficient (K{sub L}a) of NMHC was enhanced by 50% under the NaOCl and surfactant conditions, as compared to typical wet scrubber. Further, this study establishes the fuzzy equations of the ACS, including the relationship between the removal efficiency and K{sub L}a, liquid/gas ratio, pH and C{sub NaOCl}.

  4. Cadmium chronic administration to lactating ewes. Reproductive performance, cadmium tissue accumulation and placental transfer

    Floris, B.; Bomboi, G.; Sechi, P.; Marongiu, M. L. [Sassari Univ., Sassari (Italy). Dipt. di Biologia Animale; Pirino, S. [Sassari Univ., Sassari (Italy). Ist. di Patologia Generale, Anatomia Patologica e Clinica Ostetrico-chirurgica Veterinaria

    2000-12-01

    20 lactating ewes were allotted to two groups: 10 subjects received orally 100 mg/day of CdCl{sub 2} for 108 consecutive days, and the remaining 10 acted as control. Reproductive performance in ewes and cadmium tissue accumulation, both in ewes and their lambs, were investigated. The results showed that in ewes: 1) the regular cadmium intestinal intake negatively influences all reproductive parameters; 2) cadmium is particularly accumulated in kidney and liver, bur also in mammary gland, although at distinctly lower level; 3) chronic administration does not increase cadmium placental transfer in lactating pregnant subjects. [Italian] 20 pecore in lattazione sono state suddivise in 2 gruppi: 10 soggetti ricevettero per os 100 mg/giorno di CdCl{sub 2} per 108 giorni consecutivi, e i restanti 10 funsero da controllo. Sono stati studiati i parametri riproduttivi delle pecore e l'accumulo di cadmio nei tessuti, sia delle pecore che dei loro agnelli. I risultati hanno mostrato che negli ovini: 1) il regolare assorbimento intestinale di cadmio influenza negativamente tutti i parametri riproduttivi; 2) il cadmio viene accumulato principalmente nei reni e nel fegato, ma anche dalla ghiandola mammaria, sebbene in misura nettamente inferiore; 3) la somministrazione cronica di cadmio nei soggetti gravidi non incrementa il suo passaggio transplacentare.

  5. Concentration of Cadmium in Cacao Beans and its Relationship with Soil Cadmium in Southern Ecuador

    The concentration of cadmium (Cd) in cacao (Theobroma cacao, L.) beans above a critical level (0.6 mg kg-1 established by the European Union) has raised concerns of safety in the consumption of cacao-based chocolate (dark chocolate). Currently, little is available regarding Cd concentration in soil,...

  6. Determining of the level of lead and cadmium contamination in pregnant women living in an exposed mining area of Peru

    It is the objective of this study to determine in the first year the level of acute pollution and their nutritional status in pregnant women living in a lead and cadmium exposed mining area of Peru. The complete project will focus on delivering women and their infants who are one of the most vulnerable groups of the life cycle. It is of particular interest to investigate the impact of pollution not only in the mother but also the possible transfer to the infant. (author)

  7. Cadmium adsorption in montmorillonite as affected by glyphosate

    WANG Yu-jun; ZHOU Dong-mei; LUO Xiao-san; SUN Rui-juan; CHEN Huai-man

    2004-01-01

    Behaviors of soil heavy metals are often affected by coexisting herbicides due to their physical and chemical interaction. Effect of glyphosate, an herbicide containing -PO32- and -COOH groups, on cadmium adsorption in montmorillonite was studied in detail. The results showed that cadmium adsorption quantity in montmorillonite increased with increasing soil solution pH and cadmium concentration as usual, but decreased with glyphosate, which is due to the formation of a low affinity complex of Cd and glyphosate and decreasing solution pH induced by glyphosate addition. When the equilibrium solution pH was below 6.7, glyphosate has little effect on cadmium adsorption, but when the equilibrium solution pH was above 6.7, glyphosate significantly decreased cadmium adsorption quantity in montmorillonite. In addition, the adding order of Cd and glyphosate also influenced Cd adsorption quantity in montmorillonite.

  8. Cadmium sorption and mobility in sludge-amended soil

    Cadmium sorption was examined in three soils that were unamended, freshly amended, or preconditioned with gamma-irradiated sewage sludge. Metal sorption in the same soils treated with a CaCl2-extract of the sludge was also studied. Cadmium sorption was greatest in the unamended soils, less in soils preconditioned with sludge, and least in the freshly amended soils and sludge-extract-treated soils. The authors attempted to explain the treatment effects on the basis of reduced free metal ion activity, but the explanations were not adequate. Despite the reduction in metal retention effected by various treatments, cadmium mobility was very limited. Short- or long-term leaching studies showed cadmium movement to be limited to 1 or 2 m below the zone of sludge (109Cd) incorporation. Cadmium mobility is expected to be very limited in calcareous soils, regardless of sludge treatments. 24 references, 1 figure, 5 tables

  9. Amorphous tin-cadmium oxide films and the production thereof

    Li, Xiaonan; Gessert, Timothy A

    2013-10-29

    A tin-cadmium oxide film having an amorphous structure and a ratio of tin atoms to cadmium atoms of between 1:1 and 3:1. The tin-cadmium oxide film may have an optical band gap of between 2.7 eV and 3.35 eV. The film may also have a charge carrier concentration of between 1.times.10.sup.20 cm.sup.-3 and 2.times.10.sup.20 cm.sup.-3. The tin cadmium oxide film may also exhibit a Hall mobility of between 40 cm.sup.2V.sup.-1 s.sup.-1 and 60 cm.sup.2V.sup.-1 s.sup.-1. Also disclosed is a method of producing an amorphous tin-cadmium oxide film as described and devices using same.

  10. Transient behavior of cadmium in a grassland arthropod food chain

    Biological assimilation and transport of cadmium were determined for an arthropod food chain in an east Tennessee grassland community. Laboratory experiments demonstrated that there were no significant differences (P greater than 0.05) in assimilation rates (17 percent assimilation per day) or biological half-lives (7 days) of 109Cd either as soluble nitrate or insoluble oxide in crickets under identical conditions. Field experiments demonstrated that primary consumers (crickets) accumulated 109Cd much more rapidly (uptake rate = 0.55 day-1) than did the spider predators (uptake rate = 0.08 day-1). Equilibrium concentrations in crickets were obtained in 9 days (0.04 ppM cadmium), while equilibrium was not reached in spiders during the 30-day study. Food-chain concentration of cadmium did not occur as crickets accumulated levels of cadmium 60 percent of that in their vegetation food sources and spiders accumulated only 70 percent of the cadmium present in the cricket tissues

  11. Synthesis of cadmium chalcogenide nanotubes at room temperature

    Pan, Jun

    2012-10-01

    Cadmium chalcogenide (CdE, E=S, Se, Te) polycrystalline nanotubes have been synthesized from precursor of CdS/cadmium thiolate complex at room temperature. The precursor was hydrothermally synthesized at 180 °C using thioglycolic acid (TGA) and cadmium acetate as starting materials. The transformation from the rod-like precursor of CdS/cadmium thiolate complex to CdS, CdSe and CdTe nanotubes were performed under constant stirring at room temperature in aqueous solution containing S 2-, Se 2- and Te 2-, respectively. The nanotube diameter can be controlled from 150 to 400 nm related to the dimension of templates. The XRD patterns show the cadmium chalcogenide nanotubes all corresponding to face-centered cubic structure. © 2012 Elsevier B.V. All rights reserved.

  12. Effect of pregnancy on cadmium-treated rats

    Takizama, Y. (Akita Univ. School of Medicine, Japan); Nakamura, I.; Kurayama, R.; Hirasawa, F.; Kawai, K.

    1982-01-01

    It is well known that itai-itai disease with the osteopathy is broken out among multiparas, 40 years of age and up Japanese residents. In this paper we described an experimental study of effect of pregnancy on cadmium treated rats. Female mature rats were administered drinking water containing 50 and 200 ppm cadmium as CdCl/sub 2/. During 180 days of the experiment, three times of pregnancy were succesful, though slight depression of body weight gain was noticed in the 200 ppm group. The cadmium was accumulated in the kidneys, liver and bone proportionally to the amount of cadmium administered. No significant change was recognized in serum calcium, phosphorus and alkaline phosphatase levels after 180 days. Though cadmium 200 ppm treated rats showed slight histological lesions in the proximal convoluted tubules of the kidney, there appeared to be no osteomalacia including excess formation of osteoid tissue.

  13. Cadmium in the Amazonian Guajara Estuary: Distribution and remobilization

    Nascimento, S.F. [Instituto de Quimica, Departamento de Geoquimica, Universidade Federal Fluminense (Brazil)]. E-mail: nascimento@lisa.univ-paris12.fr; Kurzweil, H. [Institut fuer Petrologie, Universitaet Wien (Austria); Wruss, W. [Institut fuer Chemische Technologie anorganischer Stoffe, Technische Univesitaet Wien (Austria); Fenzl, N. [Nucleo de Altos Estudos Amazonicos, Universidade Federal do Para (Brazil)

    2006-03-15

    Extremely high total cadmium concentrations (average about 500 mg/kg) together with very small (average of 1.1 {mu}g/l) dissolved available cadmium have been found in the more acidic deeper layers of the bottom sediments of the Brazilian Amazonian Guajara Estuary. The paper shows that climatic changes and the periodic input of the Atlantic waters into the Estuary appear to have no direct influence on annual average total cadmium concentration, but they affect accumulation, distribution and remobilization of cadmium in different ways during the rainy season (February/March) and the dry season (November/December). Even if only a very small part of the total Cd is available, the concentrations of dissolved Cd in the Estuary are still high enough to cause environmental concern, if compared with concentrations in natural freshwater ecosystems. - Distribution and remobilization of cadmium is affected differently by season.

  14. Patterns of gene expression in carp liver after exposure to a mixture of waterborne and dietary cadmium using a custom-made microarray

    Gene expression changes in carp liver tissue were studied after acute (3 and 24 h) and subchronic (7 and 28 days) exposure to a mixture of waterborne (9, 105 and 480 μg/l) and dietary (9.5, 122 and 144 μg/g) cadmium, using a custom-made microarray. Suppression subtractive hybridization-PCR (SSH-PCR) was applied to isolate a set of 643 liver genes, involved in multiple biological pathways, such as energy metabolism (e.g. glucokinase), immune response (e.g. complement C3) and stress and detoxification (e.g. cytochrome P450 2F2, glutathione-S-transferase pi). These genes were subsequently spotted on glass-slides for the construction of a custom-made microarray. Resulting microarray hybridizations indicated a highly dynamic response to cadmium exposure. At low exposure concentrations (9 μg/l through water and 9.5 μg/g dry weight through food) mostly energy-related genes (e.g. glucokinase, elastase) were influenced, while a general stress response was obvious through induction of several stress-related genes, including hemopexin and cytochrome P450 2F2, at high cadmium concentrations. In addition, fish exposed to the highest cadmium concentrations showed liver damage after 7 days of exposure, as measured by elevated alanine transaminase activity in plasma and increased liver water content (wet-to-dry weight ratio). Moreover, decreased hematocrit and growth were found at the end of the experiment. Altogether this study clearly demonstrated the importance of varying exposure conditions for the characterization of the molecular impact of cadmium and showed that microarray results can provide important information, required to unravel the molecular events and responses related to cadmium exposure

  15. In vitro studies of the genotoxic effects of bitumen and coal-tar fume condensates: comparison of data obtained by mutagenicity testing and DNA adduct analysis by 32P-postlabelling.

    De Méo, M; Genevois, C; Brandt, H; Laget, M; Bartsch, H; Castegnaro, M

    1996-08-14

    Bitumens contain traces of polycyclic aromatic compounds (PACs), a part of which will end up in the fumes emitted during hot handling of bitumen-containing products, e.g. during roadpaving. Although exposure of workers to these fumes is low, it might lead to health problems. Studies on bitumen fume condensates (BFCs) showed weak to moderate mutagenic activities, but studies on DNA adduct formation have not been reported. Therefore, a study was initiated in which fumes were generated from two road grade bitumens, in such a way that they were representative of the fumes produced in the field. The combined vapour/particulates were tested in vitro for their ability to produce DNA adducts and in modified Ames mutation assays, using a number of different strains. An attempt was made to relate the results to chemical data, such as the content of a number of individual polycyclic aromatic hydrocarbons (PAHs) and with a measure for the total PAC content. As a reference material fume condensate from coal-tar (coal-tar pitch volatiles; CTPV) were subjected to the same tests. All fume condensates tested were mutagenic to all strains and induced the formation of DNA adducts. The patterns of DNA adducts, obtained by 32P-postlabelling, arising from the BFCs were qualitatively different from the patterns of adducts obtained from the CTPVs, implying qualitative differences in the nature of the compounds responsible for the formation of these adducts. This is corroborated by the observation that for BFCs quantitative adduct levels are higher than would be expected based on the PAH content. These data thus indicate that the PAHs analysed are not the sole components responsible for adduct formation from BFCs, but that an important contribution comes from other (hetero- and/or substituted-) PACs. PMID:8760390

  16. In vitro studies of the genotoxic effects of bitumen and coal-tar fume condensates: comparison of data obtained by mutagenicity testing and DNA adduct analysis by {sup 32}P-postlabelling

    De Meo, M.; Genevois, C.; Brandt, H.; Laget, M.; Bartsch, H.; Castegnaro, M. [Laboratoire de Biogenotoxicologie et Mutagenese Environnementale, Marseille (France). Faculte de Pharmcie

    1996-08-14

    Bitumens contain traces of polycyclic aromatic compounds (PACs), a part of which will end up in fumes emitted during hot handling of bitumen-containing products, e.g. during road paving. Exposure of workers to these fumes might lead to health problems. Studies on bitumen fume condensates (BFCs) showed mutagenic activities, but studies on DNA adduct formation have not been reported. Thus a study was initiated in which fumes were generated from two road grade bitumens which were representative of the fumes produced in the field. The combined vapour/particulates were tested in vitro for their ability to produce DNA adducts and in modified Ames mutation assays. Results were related to chemical data, such as the content of a number of individual polycyclic aromatic hydrocarbons (PAHs) and with a measure for total PAC content. As a reference material fume condensate from coal tar (coal-tar pitch volatiles; CTPV) were subjected to the same tests. All fume condensates were tested were mutagenic to all strains and induced the formation of DNA adducts. The patterns of DNA adducts arising from the BFCs were qualitatively different from the patterns of adducts obtained from the CTPVs, implying qualitative differences in the nature of the compounds responsible for their formation. This is corroborated by the observation that for BFCs quantitative adduct levels are higher than would be expected based on the PAH content. These data thus indicate that the PAHs analysed are not the sole components responsible for adduct formation from BFCs, but that an important contribution comes from other (hetero- and/or substituted-) PACs. 32 refs., 2 figs., 3 tabs.

  17. Heavy-metal contamination of soils in Saxony/Germany by foundry fumes and low-cost rapid analyses of contaminated soils by XRF

    Mucke, D.

    2012-04-01

    Heavy-metal contamination of soils in Saxony/Germany by foundry fumes and low-cost rapid analysis of contaminated soils by XRF Dieter Mucke, Rolf Kumann, Sebastian Baldauf GEOMONTAN Gesellschaft für Geologie und Bergbau mbH&Co.KG, Muldentalstrasse 56, 09603 Rothenfurth, Saxony/Germany For hundreds of years in the Ore Mountains between Bohemia and Saxony silver and other ores are produced and smelted. Sulphide- and sulpharsenide-ores needed to be roasted first. In doing so the sulphide sulphur was oxidised under formation of sulphur dioxide SO2 and arsenide conversed into elemental arsenic and arsenide trioxide As2O3 respectively. Also the metals lead, cadmium and zinc are components of hut smokes, in the field of nickel foundries also nickel. The contents of soils basically reflect the geogenic conditions, which are caused by decomposition- and relocation-effects of the mineralisations, in the area of foundries also with influences by with the hut smokes anthropogenic mobilised elements. The Saxonian Agency for Environment and Geology drafted in 1992 a Soil Investigation Program with the aim of investigation of the contamination of Saxonian soils with arsenic and toxic heavy metals. In order of this Agency GEOMONTAN investigated 1164 measuring points in the grid 4 * 4 km.soil profiles and extracted soil samples for analysis. In the result of the laboratory examinations the Agency edited the "Soil atlas of the Free State of Saxony". 27 elements, pH and PAK are shown in detailed maps and allow in whole Saxony the first assessment of the contamination of soils with arsenic and toxic heavy metals. Each of the investigated soil profiles represent an area of 16 km2. Already by the different use of the districts (agricultural, industrial, urban) restricts representative values. GEOMONTAN in the meantime used at the exploration of a copper deposit in Brandenburg/Germany with approx. 50,000 single tests at drill cores a very fast low-cost method: the X Ray fluorescence

  18. Acute abdomen

    Acute abdomen may be connected with the injury of one of the internal organs, injury of large blood vessels, with the spreading of pains from some other area. It may also be a manifestation of systemic disease or poisoning. The main purposes of radiodiagnosis are: determination of the cause of clinical syndrome; determination of the localization and spreading of pathological changes in abdominal organs; finding out the character of complications. If the data of the ordinary roentgenological investiagtion and isn't complete, the computer tomography of abdominal and pelvic cavities is needed

  19. Fast-neutron scattering from elemental cadmium

    Neutron differential-elastic-scattering cross sections of elemental cadmium are measured from approx. = 1.5 to 4.0 MeV at incident-neutron energy intervals of 50 to 200 keV and at 10 to 20 scattering angles distributed between approx. = 20 and 160 degrees. Concurrently, lumped-level neutron inelastic-excitation cross sections are measured. The experimental results are used to deduce parameters of an optical-statistical model that is descriptive of the observables and are compared with corresponding quantities given in ENDF/B-V

  20. Sorption of Cadmium on Na-Bentonite

    The sorption of Cd radionuclide into Na-bentonite as candidate for buffer material in the radioactive waste disposal system has been performed. Cadmium was used for this study as a model for bivalence elements. Batch experiment was adopted to study sorption isotherm, influence of carbonate and influence of EDTA. In a simple media, pure water, Cd was retained with a high affinity. Two stages Freundlich sorption isotherm was shown, with high coefficient distribution and sorption capacities. It is shown that the presence of carbonate in solution was not affect significantly to the sorption. While the presence of EDTA, decrease the distribution coefficient value. (author)

  1. Sources of cadmium exposure among healthy premenopausal women

    Background: Cadmium, a persistent and widespread environmental pollutant, has been associated with kidney function impairment and several diseases. Cigarettes are the dominant source of cadmium exposure among smokers; the primary source of cadmium in non-smokers is food. We investigated sources of cadmium exposure in a sample of healthy women. Methods: In a cross-sectional study, 191 premenopausal women completed a health questionnaire and a food frequency questionnaire. The cadmium content of spot urine samples was measured with inductively-coupled plasma mass spectrometry and normalized to urine creatinine content. Multivariable linear regression was used to estimate the strength of association between smoking habits and, among non-smokers, usual foods consumed and urinary cadmium, adjusted for age, race, multivitamin and supplement use, education, estimated total energy intake, and parity. Results: Geometric mean urine creatinine-normalized cadmium concentration (uCd) of women with any history of cigarette smoking was 0.43 μg/g (95% confidence interval (CI): 0.38-0.48 μg/g) and 0.30 μg/g (0.27-0.33 μg/g) among never-smokers, and increased with pack-years of smoking. Analysis of dietary data among women with no reported history of smoking suggested that regular consumption of eggs, hot cereals, organ meats, tofu, vegetable soups, leafy greens, green salad, and yams was associated with uCd. Consumption of tofu products showed the most robust association with uCd; each weekly serving of tofu was associated with a 22% (95% CI: 11-33%) increase in uCd. Thus, uCd was estimated to be 0.11 μg/g (95% CI: 0.06-0.15 μg/g) higher among women who consumed any tofu than among those who consumed none. Conclusions: Cigarette smoking is likely the most important source of cadmium exposure among smokers. Among non-smokers, consumption of specific foods, notably tofu, is associated with increased urine cadmium concentration. - Research highlights: →Urine cadmium, usual

  2. Sources of cadmium exposure among healthy premenopausal women

    Adams, Scott V., E-mail: sadams@fhcrc.org [Fred Hutchinson Cancer Research Center, PO Box 19024, M4-B402, Seattle, WA 98109 (United States); Department of Epidemiology, University of Washington, Box 357236, Seattle, WA 98195 (United States); Newcomb, Polly A. [Fred Hutchinson Cancer Research Center, PO Box 19024, M4-B402, Seattle, WA 98109 (United States); Department of Epidemiology, University of Washington, Box 357236, Seattle, WA 98195 (United States); Shafer, Martin M. [Environmental Chemistry and Technology Program, University of Wisconsin and Wisconsin State Laboratory of Hygiene, Madison, WI (United States); Atkinson, Charlotte [Department of Oral and Dental Science, Bristol Dental School, Bristol (United Kingdom); Bowles, Erin J. Aiello [Group Health Research Institute, Seattle, WA (United States); Newton, Katherine M. [Department of Epidemiology, University of Washington, Box 357236, Seattle, WA 98195 (United States); Group Health Research Institute, Seattle, WA (United States); Lampe, Johanna W. [Fred Hutchinson Cancer Research Center, PO Box 19024, M4-B402, Seattle, WA 98109 (United States); Department of Epidemiology, University of Washington, Box 357236, Seattle, WA 98195 (United States)

    2011-04-01

    Background: Cadmium, a persistent and widespread environmental pollutant, has been associated with kidney function impairment and several diseases. Cigarettes are the dominant source of cadmium exposure among smokers; the primary source of cadmium in non-smokers is food. We investigated sources of cadmium exposure in a sample of healthy women. Methods: In a cross-sectional study, 191 premenopausal women completed a health questionnaire and a food frequency questionnaire. The cadmium content of spot urine samples was measured with inductively-coupled plasma mass spectrometry and normalized to urine creatinine content. Multivariable linear regression was used to estimate the strength of association between smoking habits and, among non-smokers, usual foods consumed and urinary cadmium, adjusted for age, race, multivitamin and supplement use, education, estimated total energy intake, and parity. Results: Geometric mean urine creatinine-normalized cadmium concentration (uCd) of women with any history of cigarette smoking was 0.43 {mu}g/g (95% confidence interval (CI): 0.38-0.48 {mu}g/g) and 0.30 {mu}g/g (0.27-0.33 {mu}g/g) among never-smokers, and increased with pack-years of smoking. Analysis of dietary data among women with no reported history of smoking suggested that regular consumption of eggs, hot cereals, organ meats, tofu, vegetable soups, leafy greens, green salad, and yams was associated with uCd. Consumption of tofu products showed the most robust association with uCd; each weekly serving of tofu was associated with a 22% (95% CI: 11-33%) increase in uCd. Thus, uCd was estimated to be 0.11 {mu}g/g (95% CI: 0.06-0.15 {mu}g/g) higher among women who consumed any tofu than among those who consumed none. Conclusions: Cigarette smoking is likely the most important source of cadmium exposure among smokers. Among non-smokers, consumption of specific foods, notably tofu, is associated with increased urine cadmium concentration. - Research highlights: {yields

  3. Modeling cadmium in the feed chain and cattle organs

    van der Fels-Klerx, I.

    2011-01-01

    Full Text Available The objectives of this study were to estimate cadmium contamination levels in different scenarios related to soil characteristics and assumptions regarding cadmium accumulation in the animal tissues, using quantitative supply chain modeling. The model takes into account soil cadmium levels, soil pH, soil-to-plant transfer, animal consumption patterns, and transfer into animal organs (liver and kidneys. The model was applied to cattle up to the age of six years which were fed roughage (maize and grass and compound feed. Cadmium content in roughage and cadmium intake by cattle were calculated for six different (soil scenarios varying in soil cadmium levels and soil pH. For each of the six scenarios, the carry-over of cadmium from intake into the cattle organs was estimated applying two model assumptions, i.e., linear accumulation and a steady state situation. The results showed that only in the most extreme soil scenario (cadmium level 2.5 mg.kg-1, pH 4.5, cadmium exceeded the EC maximum tolerated level in roughage. Assuming linear accumulation, cadmium levels in organs of cattle up to six years of age, ranged from 0.37-4.03 mg.kg-1 of fresh weight for kidneys and from 0.07 to 0.77 mg.kg-1 of fresh weight for livers. The maximum tolerated levels in one or both organs were exceeded in several scenarios. When considering organ excretion of cadmium, internal cadmium levels in organs were approximately one order of magnitude lower as compared to the results of the linear accumulation model. In this case only in the most extreme soil scenario, the maximum tolerated level in the kidney was exceeded. It was concluded that the difference between the two assumptions (linear model versus a steady state situation to estimate cadmium carry-over in cattle is negligible in the animal's first five years of life, but will become relevant at higher ages. For the current case, the linear approach is a good descriptor for worst case situations. Furthermore, this

  4. Fluorescence detection of intracellular cadmium with Leadmium Green.

    Malaiyandi, Latha M; Sharthiya, Harsh; Dineley, Kirk E

    2016-08-01

    Leadmium Green is a commercially available, small molecule, fluorescent probe advertised as a detector of free intracellular cadmium (Cd(2+)) and lead (Pb(2+)). Leadmium Green has been used in various paradigms, such as tracking Cd(2+) sequestration in plant cells, heavy metal export in protozoa, and Pb(2+) absorption by vascular endothelial cells. However very little information is available regarding its affinity and selectivity for Cd(2+), Pb(2+), and other metals. We evaluated the in vitro selectivity of Leadmium Green using spectrofluorimetry. Consistent with manufacturer's claims, Leadmium Green was sensitive to Cd(2+) (KD ~600 nM) and also Pb(2+) (KD ~9.0 nM) in a concentration-dependent manner, and furthermore proved insensitive to Ca(2+), Co(2+), Mn(2+) and Ni(2+). Leadmium Green also responded to Zn(2+) with a KD of ~82 nM. Using fluorescence microscopy, we evaluated Leadmium Green in live mouse hippocampal HT22 cells. We demonstrated that Leadmium Green detected ionophore-mediated acute elevations of Cd(2+) or Zn(2+) in a concentration-dependent manner. However, the maximum fluorescence produced by ionophore-delivered Zn(2+) was much less than that produced by Cd(2+). When tested in a model of oxidant-induced liberation of endogenous Zn(2+), Leadmium Green responded weakly. We conclude that Leadmium Green is an effective probe for monitoring intracellular Cd(2+), particularly in models where Cd(2+) accumulates rapidly, and when concomitant fluctuations of intracellular Zn(2+) are minimal. PMID:27260023

  5. Live and Let Die: Roles of Autophagy in Cadmium Nephrotoxicity

    Frank Thévenod

    2015-04-01

    Full Text Available The transition metal ion cadmium (Cd2+ is a significant environmental contaminant. With a biological half-life of ~20 years, Cd2+ accumulates in the kidney cortex, where it particularly damages proximal tubule (PT cells and can result in renal fibrosis, failure, or cancer. Because death represents a powerful means by which cells avoid malignant transformation, it is crucial to clearly identify and understand the pathways that determine cell fate in chronic Cd2+ nephrotoxicity. When cells are subjected to stress, they make a decision to adapt and survive, or—depending on the magnitude and duration of stress—to die by several modes of death (programmed cell death, including autophagic cell death (ACD. Autophagy is part of a larger system of intracellular protein degradation and represents the channel by which organelles and long-lived proteins are delivered to the lysosome for degradation. Basal autophagy levels in all eukaryotic cells serve as a dynamic physiological recycling system, but they can also be induced by intra- or extracellular stress and pathological processes, such as endoplasmic reticulum (ER stress. In a context-dependent manner, autophagy can either be protective and hence contribute to survival, or promote death by non-apoptotic or apoptotic pathways. So far, the role of autophagy in Cd2+-induced nephrotoxicity has remained unsettled due to contradictory results. In this review, we critically survey the current literature on autophagy in Cd2+-induced nephrotoxicity in light of our own ongoing studies. Data obtained in kidney cells illustrate a dual and complex function of autophagy in a stimulus- and time-dependent manner that possibly reflects distinct outcomes in vitro and in vivo. A better understanding of the context-specific regulation of cell fate by autophagy may ultimately contribute to the development of preventive and novel therapeutic strategies for acute and chronic Cd2+ nephrotoxicity.

  6. [Acute myocarditis].

    Combes, Alain

    2013-05-01

    Myocarditis is defined as inflammation of the myocardium accompanied by myocellular necrosis. Acute myocarditis must be considered in patients who present with recent onset of cardiac failure or arrhythmia. Fulminant myocarditis is a distinct entity characterized by sudden onset of severe congestive heart failure or cardiogenic shock, usually following a flu-like illness, parvovirus B19, human herpesvirus 6, coxsackievirus and adenovirus being the most frequently viruses responsible for the disease. Treatment of myocarditis remains largely supportive, since immunosuppression has not been proven to be beneficial for acute lymphocytic myocarditis. Trials of antiviral therapies, or immunostimulants such as interferons, suggest a potential therapeutic role but require further investigation. Lastly, early recognition of patients rapidly progressing to refractory cardiac failure and their immediate transfer to a medical-surgical center experienced in mechanical circulatory support is warranted. In this setting, ECMO should be the first-line mechanical assistance. For highly unstable patients, a Mobile Cardiac Assistance Unit, that rapidly travels to primary care hospitals with a portable ECMO system and hooks it up before refractory multiorgan failure takes hold, is the preferred option. PMID:23789482

  7. Strain differences of cadmium-induced toxicity in rats: Insight from spleen and lung immune responses.

    Demenesku, Jelena; Popov Aleksandrov, Aleksandra; Mirkov, Ivana; Ninkov, Marina; Zolotarevski, Lidija; Kataranovski, Dragan; Brceski, Ilija; Kataranovski, Milena

    2016-08-10

    The impact of genetic background on effects of acute i.p. cadmium administration (0.5mg/kg and 1mg/kg) on basic immune activity of spleen and lungs was examined in two rat strains, Albino Oxford (AO) and Dark Agouti (DA), known to react differently to chemicals. More pronounced inhibition of Concanavalin A (ConA)-induced and Interleukin (IL)-2 stimulated spleen cell proliferation as well as higher levels of nitric oxide (known to decrease cell's proliferative ability) in DA rats at 1mg/kg, along with greater inhibition of ConA-induced Interferon (IFN-γ)-production by total and mononuclear (MNC) spleen cells and IL-17 production by spleen MNC in DA vs. AO rats at this dose show greater susceptibility of this strain to Cd effects on spleen cells response. More pronounced infiltration of neutrophils/CD11b(+) cells to lungs of DA rats treated with 1mg/kg of Cd and decreased IL-17 lung cell responses noted solely in DA rats speaks in favor of their higher susceptibility to this metal. However, lack of strain disparity in lung cells IFN-γ responses show that there are regional differences as well. Novel data from this study depict complexity of the influence of genetic background on the effects of cadmium on host immune reactivity. PMID:27234498

  8. Study of the degradation mechanisms of amines used for the capture of CO{sub 2} in industrial fumes; Etude des mecanismes de degradation des amines utilisees pour le captage du CO{sub 2} dans les fumees

    Lepaumier, H

    2008-10-15

    Global warming leads to reduce greenhouse gas emissions. Post combustion CO{sub 2} capture with solvent is the most advanced technology to reduce CO{sub 2} emissions in industrial fumes. A major problem associated with chemical absorption of CO{sub 2} using the benchmark ethanolamine (MEA) is solvent degradation through irreversible side reactions with CO{sub 2} and O{sub 2} which leads to numerous harmful impacts to the process: corrosion, solvent loss, foaming, fouling, and viscosity increase. So, developing new amines with higher chemical stability is essential. This work is based on the chemical stability study of 17 different molecules. Their structures have been chosen in order to establish structure-property relationships: alkanolamines, known for gas treatment application (MEA, DEA, MDEA, AMP...), di-amines, and tri-amines without alcohol function. Impact of temperature, CO{sub 2}, and O{sub 2} on degradation has been studied. Strong experimental conditions have been used to observe significant degradation after a 15 days experiment. Separation, identification and quantification of degradation products have been performed by using different testing instructions such as gas chromatography, mass spectrometry, ionic chromatography and NMR. Different mechanisms are proposed to explain most of degradation compounds. Radical reactions (dealkylation, alkylation, ring-closure reactions and piperazinones formation) are involved under O{sub 2} pressure whereas CO{sub 2} induces ionic reactions (dealkylation, alkylation, addition, ring-closure reactions and oxazolidinones or imidazolidinones formation). Large discrepancies of stability are noticed among the different amines. Knowledge of degradation products and reaction mechanisms has thus permitted to establish some relationships between structure and chemical stability: for example, role of the amine function (primary, secondary, tertiary), impact of alkyl chain length between the two amino groups and steric

  9. Dietary cadmium intake and risk of prostate cancer: a Danish prospective cohort study

    Eriksen, Kirsten T.; Halkjær, Jytte; Jaymie R. Meliker; McElroy, Jane A.; Sørensen, Mette; Tjønneland, Anne; Raaschou-Nielsen, Ole

    2015-01-01

    Background Cadmium is classified as a human lung carcinogen based on evidence from high-exposure occupational settings. Though cadmium has no physiological role, increasing evidence suggests cadmium may mimic steroid hormones. This dual ability of being carcinogenic and hormone-like makes cadmium a concern for hormone-related cancers. Causes of prostate cancer are not clear, but steroid hormones, particularly androgens and probably estrogens, may be involved. Cadmium has been positively assoc...

  10. RECURRENT SEASONAL ACUTE PSYCHOSIS

    Agarwal, Vivek

    1999-01-01

    Acute psychoses have been reported to occur more frequently in summer. This is a report of seasonal recurrence of acute psychosis in a patient. This case report emphasizes towards the biological etiology of acute psychoses.

  11. Acute cerebellar ataxia

    Cerebellar ataxia; Ataxia - acute cerebellar; Cerebellitis; Post-varicella acute cerebellar ataxia; PVACA ... Acute cerebellar ataxia in children, especially younger than age 3, may occur several weeks after an illness caused by a virus. ...

  12. Cellular mechanisms of cadmium-induced toxicity: a review.

    Rani, Anju; Kumar, Anuj; Lal, Ankita; Pant, Manu

    2014-08-01

    Cadmium is a widespread toxic pollutant of occupational and environmental concern because of its diverse toxic effects: extremely protracted biological half-life (approximately 20-30 years in humans), low rate of excretion from the body and storage predominantly in soft tissues (primarily, liver and kidneys). It is an extremely toxic element of continuing concern because environmental levels have risen steadily due to continued worldwide anthropogenic mobilization. Cadmium is absorbed in significant quantities from cigarette smoke, food, water and air contamination and is known to have numerous undesirable effects in both humans and animals. Cadmium has a diversity of toxic effects including nephrotoxicity, carcinogenicity, teratogenicity and endocrine and reproductive toxicities. At the cellular level, cadmium affects cell proliferation, differentiation, apoptosis and other cellular activities. Current evidence suggests that exposure to cadmium induces genomic instability through complex and multifactorial mechanisms. Most important seems to be cadmium interaction with DNA repair mechanism, generation of reactive oxygen species and induction of apoptosis. In this article, we have reviewed recent developments and findings on cadmium toxicology. PMID:24117228

  13. Cadmium (II) removal mechanisms in microbial electrolysis cells.

    Colantonio, Natalie; Kim, Younggy

    2016-07-01

    Cadmium is a toxic heavy metal, causing serious environmental and human health problems. Conventional methods for removing cadmium from wastewater are expensive and inefficient for low concentrations. Microbial electrolysis cells (MECs) can simultaneously treat wastewater, produce hydrogen gas, and remove heavy metals with low energy requirements. Lab-scale MECs were operated to remove cadmium under various electric conditions: applied voltages of 0.4, 0.6, 0.8, and 1.0V; and a fixed cathode potential of -1.0V vs. Ag/AgCl. Regardless of the electric condition, rapid removal of cadmium was demonstrated (50-67% in 24h); however, cadmium concentration in solution increased after the electric current dropped with depleted organic substrate under applied voltage conditions. For the fixed cathode potential, the electric current was maintained even after substrate depletion and thus cadmium concentration did not increase. These results can be explained by three different removal mechanisms: cathodic reduction; Cd(OH)2 precipitation; and CdCO3 precipitation. When the current decreased with depleted substrates, local pH at the cathode was no longer high due to slowed hydrogen evolution reaction (2H(+)+2e(-)→H2); thus, the precipitated Cd(OH)2 and CdCO3 started dissolving. To prevent their dissolution, sufficient organic substrates should be provided when MECs are used for cadmium removal. PMID:26970043

  14. Mobility, bioavailability, and toxic effects of cadmium in soil samples

    Total concentration is not a reliable indicator of metal mobility or bioavailability in soils. The physicochemical form determines the behavior of metals in soils and hence the toxicity toward terrestrial biota. The main objectives of this study were the application and comparison of three approaches for the evaluation of cadmium behavior in soil samples. The mobility and bioavailability of cadmium in five selected soil samples were evaluated using equilibrium speciation (Windermere humic aqueous mode (WHAM)), extraction procedures (Milli-Q water, DMSO, and DTPA), and a number of bioassays (Microtox, growth inhibition test, contact toxicity test, and respiration). The mobility, represented by the water-extractable fraction corresponded well with the amount of cadmium in the soil solution, calculate using the WHAM (r2=0.96, P<0.001). The results of the ecotoxicologica evaluation, which represent the bioavailable fraction of cadmium, correlated well with DTPA extractability and also with the concentration of free cadmium ion, which is recognized as the most bioavailable metal form. The results of the WHAM as well as the results of extraction experiments showed a strong binding of cadmium to organic matter and a weak sorption of cadmium to clay minerals

  15. Cadmium cutoff energy for MCNP modeling of dosimetry reactions

    Reactor pressure vessel neutron fluence calculations are verified by comparing calculated reaction rates of dosimetry foils assumed to be placed in the cavity surrounding the pressure vessel with corresponding experimentally determined dosimetry reaction rates at the same location. The irradiated foils used are bare and cadmium covered. The cadmium-covered foils see a different neutron flux than the uncovered foils. Computer models computing reaction rates for the foils must approximate the effect of the cadmium foil cover. The MCNP code modeling of reactor cavity dosimetry reactions to validate the computed neutron flux hitting the pressure vessel of a pressurized water reactor (PWR) requires the choice of an appropriate cadmium cutoff energy. Since the neutron spectrum is harder in the cavity than in the core, the same cadmium cutoff energy may not be universally applied. The correct cutoff energy for the cavity of a PWR was computed by using MCNP4a and a representative cavity spectrum. Four cadmium-covered foil reactions were analyzed, and the appropriate energy cutoff was determined to be ∼ 0.6 eV for ∼0.5-mm-thick cadmium covers

  16. Bacterial bioremediation of aquatic cadmium 11 of area of Pakistan

    Cadmium Cd/sup +2/ pollution arises mainly from contamination of minerals used in agriculture and from industrial process. The usual situation is of large volume of soil and H/sub 2/O that are contaminated with low but significant concentration of Cd/sup +2/. Cadmium is one of the most dangerous heavy metal both to human health and aquatic ecosystem. Microorganisms have developed different strategies to regulate uptake and to detoxify heavy metals viz; by different mechanisms i.e. by adsorption to cell surface, by intercellular accumulation, precipitation, biosynthesis of metallothioneins to volatile compounds. Microcosm experiments in chemostat incubated at 20 deg. C showed that Cadmium Contamination does not greatly affect bacterial communities in cultures contaminated with up to 1mg CdI/sup -1/. acterial productivity remains unchanged and Cadmium- resistant strains arise quickly and in great number. The cadmium accumulation by bacteria depend on the bacterial productivity. The free bacteria can accumulate up to 1200 ppm Cadmium Where as the adhering bacteria concentrate up to 6100 ppm. At a steady state, 11-29% Cadmium is removed from the water phase of cultures. This paper includes Cd (II) removal by Bacteria from waste water of Wah Cantonment Pakistan. (author)

  17. Accumulation and distribution of arsenic and cadmium by tea plants

    Yuan-zhi SHI; Jian-yun RUAN; Lifeng MA; Wen-yan HAN; Fang WANG

    2008-01-01

    It is important to research the rules about accumulation and distribution of arsenic and cadmium by tea plants, which will give us some scientific ideas about how to control the contents of arsenic and cadmium in tea. In this study, by field inves- tigation and pot trial, we found that mobility of arsenic and cadmium in tea plants was low. Most arsenic and cadmium absorbed were fixed in feeding roots and only small amount was transported to the above-ground parts. Distribution of arsenic and cadmium, based on their concentrations of unit dry matter, in tea plants grown on un-contaminated soil was in the order: feeding roots>stems≈main roots>old leaves>young leaves. When tea plants were grown on polluted soils simulated by adding salts of these two metals, feeding roots possibly acted as a buffer and defense, and arsenic and cadmium were transported less to the above- ground parts. The concentration of cadmium in soil significantly and negatively correlated with chlorophyll content, photosyn- thetic rate, transpiration rate and biomass production of tea plants.

  18. Cadmium Uptake in Synechococcus aquatilis (Reynaud Strain SY01

    Ruperto Vallarta Jr.

    1998-12-01

    Full Text Available Cadmium uptake in Synechococcus aquatilis (Reynaud Strain SY01 showed a biphasic behavior, with an initial rapid passive cell wall interaction phase and a later slow intracellular cation uptake process. The cell wall uptake process followed Michaelis-Menten kinetics. The apparent Km of the uptake system was 38.89 µM, a relatively high affinity Km value compared to other metal uptake systems. Fitting of experimental data to the Langmuir and Freundlich adsorption isotherms showed that binding of cadmium to the cell surface was monolayer and/or multilayer, although the monolayer adsorption was more probable, as exemplified by a high correlation coefficient. This could be explained by the presence of a strong primary binding site which was responsible for a monolayer adsorption and a weak secondary binding site which could be responsible for a multilayer adsorption. The uptake process was found to be relatively specific for cadmium. Equimolar amounts (200 µM of cobalt, nickel, magnesium, and copper did not significantly affect cadmium uptake. Synechococcus aquatilis Strain SY01 cells also showed an efflux mechanism for cadmium, although the amount of excluded cadmium was insignificant compared with the amount of adsorbed cadmium in the cell wall.

  19. Blood cadmium concentration and lipid profile in Korean adults

    Kim, Kisok, E-mail: kimkisok@kmu.ac.kr [Department of Public Health, Keimyung University, 1000 Shindang-dong, Daegu 704-701 (Korea, Republic of)

    2012-01-15

    Although animal experiments have shown that cadmium exposure induces alterations in lipid profiles, no epidemiological study of this relationship has been performed. The objective of this study was to evaluate the association between blood cadmium concentration and blood lipid levels in Korean adults. A cross-sectional study comprising participants (n=3903) aged 20 years or older from the 2005, 2008, and 2009 Korea National Health and Nutrition Examination Surveys was conducted. Demographic characteristics and dietary intake were obtained from the participants by questionnaire, and cadmium and lipid levels were determined by analysis of blood samples. After adjusting for demographic and dietary factors, blood concentration of cadmium was positively associated with the risk of low high-density lipoprotein cholesterol (HDL-C) in a dose-dependent manner (p for trend <0.001). In addition, the odds ratios (ORs) of a high triglyceride to HDL-C ratio was significantly increased in the high blood cadmium groups [OR=1.36; 95% confidence interval (CI), 1.03-1.79 for fourth quintile and OR=1.41; 95% CI, 1.07-1.86 for fifth quintile] compared with the lowest quintile group. However, high blood cadmium was not associated with a risk of high total cholesterol, high low-density lipoprotein cholesterol, or high triglycerides. These data suggest that an increased cadmium body burden increases the risk of dyslipidemia, mainly due to the increased risk of low HDL-C and the high ratio of triglycerides to HDL-C.

  20. Screening of Amaranth Cultivars (Amaranthus mangostanus L.) for Cadmium Hyperaccumulation

    FAN Hong-li; ZHOU Wei

    2009-01-01

    The potential harm of soil cadmium pollution to ecological environment and human health has been increasingly widely concerned. Phytoremediation, as a kind of new and effective technology, has become an important method for cleaning up cadmium in contaminated sites. The amaranth (Amaranthus mangostanus L.) is widely distributed and has abundant varieties in China, its rapid growth and large biomass can be served as candidate for cadmium hyperaccumulators for phytoremediation. To obtain cadmium hyper-accumulator, Cd uptake in 23 amaranth euitivars from different ecological region was investigated under hydroponic culture condition. Meanwhile, pot experiment was established to probe phytoremediation potentiality of Cd contaminated soil by amaranth. Three treatment (Cd 5, 10, and 25 mg kg-1) were imposed to red soil, yellow brown soil, and vegetable soil. The results showed that under hydroponic culture with Cd 3 mg L-1, the cadmium concentration in the shoots of the cultivar Tianxingmi reached 260 mg kg-1, and its total cadmium uptake was the highest among various cultivars. In the treatment Cd 25 mg kg-1, the cadmium concentration in the shoots of the cultivar Tianxingmi reached 212 mg kg-1, while bioaccumulation factor and shoot purification rate reached 8.50 and 3.8%, respectively. Further, the total biomass and shoot biomass were not decreased significantly under Cd exposure.These results suggested that eultivar Tianxingmi is a typical Cd hyperaccumulator, and can be expected to be used in phytoremediation of Cd contaminated soil.