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Sample records for hazardous fumes udvikling

  1. A new method for infrared imaging of air currents in and around critical hazard fume hoods

    SciTech Connect

    Mulac, W.A.; McCreary, J.R. ); Schmalz, H. Thermal Surveys, Inc., Rockford, IL )

    1992-01-01

    A real time method of measuring and recording the efficacy of vapor containment in and around critical hazard fume hoods is being developed. An infrared camera whose response is restricted to a spectral range that overlaps a strong absorption band in a non-toxic gas is used to render real-time video images of the presence and flow of the gas. The gas, nitrous oxide, is ejected in a continuous stream in and around fume hoods that are to be certified capable of containing hazardous fumes. The principle advantage is that various scenarios of air flow displacement in and outside the hood can be easily investigated; the principle limitation is the necessity of high tracer gas concentration to obtain strong visualizations. We hope that this technique can be found to be an effective and safe method to test hoods in locations that were built before present regulations were promulgated.

  2. A new method for infrared imaging of air currents in and around critical hazard fume hoods

    SciTech Connect

    Mulac, W.A.; McCreary, J.R.; Schmalz, H. |

    1992-11-01

    A real time method of measuring and recording the efficacy of vapor containment in and around critical hazard fume hoods is being developed. An infrared camera whose response is restricted to a spectral range that overlaps a strong absorption band in a non-toxic gas is used to render real-time video images of the presence and flow of the gas. The gas, nitrous oxide, is ejected in a continuous stream in and around fume hoods that are to be certified capable of containing hazardous fumes. The principle advantage is that various scenarios of air flow displacement in and outside the hood can be easily investigated; the principle limitation is the necessity of high tracer gas concentration to obtain strong visualizations. We hope that this technique can be found to be an effective and safe method to test hoods in locations that were built before present regulations were promulgated.

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

    PubMed

    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

  4. Low flow fume hood

    DOEpatents

    Bell, Geoffrey C.; Feustel, Helmut E.; Dickerhoff, Darryl J.

    2002-01-01

    A fume hood is provided having an adequate level of safety while reducing the amount of air exhausted from the hood. A displacement flow fume hood works on the principal of a displacement flow which displaces the volume currently present in the hood using a push-pull system. The displacement flow includes a plurality of air supplies which provide fresh air, preferably having laminar flow, to the fume hood. The displacement flow fume hood also includes an air exhaust which pulls air from the work chamber in a minimally turbulent manner. As the displacement flow produces a substantially consistent and minimally turbulent flow in the hood, inconsistent flow patterns associated with contaminant escape from the hood are minimized. The displacement flow fume hood largely reduces the need to exhaust large amounts of air from the hood. It has been shown that exhaust air flow reductions of up to 70% are possible without a decrease in the hood's containment performance. The fume hood also includes a number of structural adaptations which facilitate consistent and minimally turbulent flow within a fume hood.

  5. Updating Older Fume Hoods.

    ERIC Educational Resources Information Center

    Saunders, G. Thomas

    1985-01-01

    Provides information on updating older fume hoods. Areas addressed include: (1) adjustment of the hood's back baffle; (2) hood air leakage; (3) light level; (4) hood location in relation to room traffic and room air; and (5) establishing and maintaining hood performance. (JN)

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

    PubMed

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

    PubMed Central

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

    2015-01-01

    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

  8. Polymer fume fever.

    PubMed

    Shimizu, Taro; Hamada, Osamu; Sasaki, Akinori; Ikeda, Mari

    2012-01-01

    A 29-year-old Japanese man presented with fever, dyspnoea and non-productive cough after massive inhalation of evaporant from a polytetrafluoroethylene-coated cooking pan. Chest CT scan showed diffuse interstitial infiltration in both lungs. Based on the patient history, images and the pan he brought to the hospital, polymer fume fever was strongly suspected. His symptoms dramatically improved over the following 2 days after admission. PMID:23230259

  9. 30 CFR 70.305 - Respiratory equipment; gas, dusts, fumes, or mists.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... NIOSH under 42 CFR part 84 shall be provided to persons exposed for short periods to inhalation hazards from gas, dusts, fumes, or mist. When the exposure is for prolonged periods, other measures to...

  10. 30 CFR 70.305 - Respiratory equipment; gas, dusts, fumes, or mists.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... NIOSH under 42 CFR part 84 shall be provided to persons exposed for short periods to inhalation hazards from gas, dusts, fumes, or mist. When the exposure is for prolonged periods, other measures to...

  11. 30 CFR 70.305 - Respiratory equipment; gas, dusts, fumes, or mists.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... NIOSH under 42 CFR part 84 shall be provided to persons exposed for short periods to inhalation hazards from gas, dusts, fumes, or mist. When the exposure is for prolonged periods, other measures to...

  12. 30 CFR 70.305 - Respiratory equipment; gas, dusts, fumes, or mists.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... NIOSH under 42 CFR part 84 shall be provided to persons exposed for short periods to inhalation hazards from gas, dusts, fumes, or mist. When the exposure is for prolonged periods, other measures to...

  13. 30 CFR 70.305 - Respiratory equipment; gas, dusts, fumes, or mists.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... NIOSH under 42 CFR part 84 shall be provided to persons exposed for short periods to inhalation hazards from gas, dusts, fumes, or mist. When the exposure is for prolonged periods, other measures to...

  14. Estimation of regional pulmonary deposition and exposure for fumes from SMAW and GMAW mild and stainless steel consumables.

    PubMed

    Hewett, P

    1995-02-01

    The particle size distributions and bulk fume densities for mild steel and stainless steel welding fumes generated using two welding processes (shielded metal arc welding [SMAW] and gas metal arc welding [GMAW]) were used in mathematical models to estimate regional pulmonary deposition (the fraction of each fume expected to deposit in each region of the pulmonary system) and regional pulmonary exposure (the fraction of each fume expected to penetrate to each pulmonary region and would be collected by a particle size-selective sampling device). Total lung deposition for GMAW fumes was estimated at 60% greater than that of SMAW fumes. Considering both the potential for deposition and the fume specific surface areas, it is likely that for equal exposure concentrations GMAW fumes deliver nearly three times the particle surface area to the lungs as SMAW fumes. This leads to the hypothesis that exposure to GMAW fumes constitutes a greater pulmonary hazard than equal exposure to SMAW fumes. The implications of this hypothesis regarding the design of future health studies of welders is discussed. PMID:7856514

  15. 222-S LABORATORY FUME HOOD TESTING STUDY

    SciTech Connect

    RUELAS, B.H.

    2007-03-26

    The 222-S Laboratory contains 155 active fume hoods that are used to support analytical work with radioactive and/or toxic materials. The performance of a fume hood was brought into question after employees detected odors in the work area while mixing chemicals within the subject fume hood. Following the event, testing of the fume hood was conducted to assess the performance of the fume hood. Based on observations from the testing, it was deemed appropriate to conduct performance evaluations of other fume hoods within the laboratory.

  16. GENERATION OF FUMES SIMULATING PARTICULATE AIR POLLUTANTS

    EPA Science Inventory

    The report describes techniques developed for generating large quantities of reproducible, stable, inorganic, fine-particle aerosol fumes. These fumes simulated particulate air pollutants emitted from power generation, basic oxygen furnaces, electric arc furnaces, and zinc smelti...

  17. Photochemical Degradation Of Organic-Solvent Fumes

    NASA Technical Reports Server (NTRS)

    Herzstock, James J.

    1990-01-01

    Quality of air in laboratory or industrial ventilation airstream enhanced by proposed technique. Source of ultraviolet light placed in airstream to degrade fumes photochemically. If fumes acceptable in degraded form, no further processing needed.

  18. [Metal fume fever, an almost forgotten disease].

    PubMed

    Yordanov, Y; Cantin, D; Le Guerroué, G; Pourriat, J-L

    2010-05-01

    Metal fume fever is an ancient and almost forgotten occupational disease found among welders. Diagnosis is made difficult by the frequency and the non-specific flue-like symptomatology. We present the cases of three patients admitted for developing the symptoms after being exposed to welding fumes. Treatment was symptom based. Severe cases have been described after exposure to military fumes. PMID:20378299

  19. Energy efficient laboratory fume hood

    DOEpatents

    Feustel, Helmut E.

    2000-01-01

    The present invention provides a low energy consumption fume hood that provides an adequate level of safety while reducing the amount of air exhausted from the hood. A low-flow fume hood in accordance with the present invention works on the principal of providing an air supply, preferably with low turbulence intensity, in the face of the hood. The air flow supplied displaces the volume currently present in the hood's face without significant mixing between the two volumes and with minimum injection of air from either side of the flow. This air flow provides a protective layer of clean air between the contaminated low-flow fume hood work chamber and the laboratory room. Because this protective layer of air will be free of contaminants, even temporary mixing between the air in the face of the fume hood and room air, which may result from short term pressure fluctuations or turbulence in the laboratory, will keep contaminants contained within the hood. Protection of the face of the hood by an air flow with low turbulence intensity in accordance with a preferred embodiment of the present invention largely reduces the need to exhaust large amounts of air from the hood. It has been shown that exhaust air flow reductions of up to 75% are possible without a decrease in the hood's containment performance.

  20. Gaps in scientific knowledge about the carcinogenic potential of asphalt/bitumen fumes.

    PubMed

    Schulte, Paul A

    2007-01-01

    Despite a relatively large body of published research, the potential carcinogenicity of asphalt/bitumen fumes is still a vexing question. Various uncertainties and gaps in scientific knowledge need to be addressed. These include uncertainties in chemistry, animal studies, and human studies. The chemistry of asphalt/bitumen fumes is complex and varies according to the source of the crude oil and the application parameters. The epidemiological studies, while showing weak evidence of lung cancer, are inconsistent and many confounding factors have not been addressed. Studies of animal exposure are also inconsistent regarding laboratory and field-generated fumes. There is a need for further human studies that address potential confounding factors such as smoking, diet, coal tar, and diesel exposures. Animal inhalation studies need to be conducted with asphalt/bitumen fumes that are chemically representative of roofing and paving fumes. Underlying all of this is the need for continued characterization of fumes so their use in animal and field studies can be properly assessed. Nonetheless, uncertainties such as these should not preclude appropriate public health actions to protect workers in the even that asphalt fumes are found to be a carcinogenic hazard. PMID:17503268

  1. Pulmonary adverse effects of welding fume in automobile assembly welders.

    PubMed

    Sharifian, Seyed Akbar; Loukzadeh, Ziba; Shojaoddiny-Ardekani, Ahmad; Aminian, Omid

    2011-01-01

    Welding is one of the key components of numerous manufacturing industries, which has potential physical and chemical health hazards. Many components of welding fumes can potentially affect the lung function. This study investigates the effects of welding fumes on lung function and respiratory symptoms among welders of an automobile manufacturing plant in Iran. This historical cohort study assesses 43 male welders and 129 office workers by a questionnaire to record demographic data, smoking habits, work history and respiratory symptoms as well as lung function status by spirometry. The average pulmonary function values of welders were lower relative to controls with dose-effect relationship between work duration and pulmonary function impairment. The prevalence of chronic bronchitis was higher in welders than controls. Our findings suggest that welders are at risk for pulmonary disease. PMID:21598218

  2. Combustion fume structure and dynamics

    SciTech Connect

    Flagan, R.C.

    1992-08-01

    The focus of this research program is on elucidating the fundamental processes that determine the particle size distribution, composition, and agglomerate structures of coal ash fumes. The ultimate objective of this work is the development and validation of a model for the dynamics of combustion fumes, describing both the evolution of the particle size distribution and the particle morphology. The study employs model systems to address the fundamental questions and to provide rigorous validation of the models to be developed. This first phase of the project has been devoted to the development of a detailed experimental strategy that will allow agglomerates with a broad range of fractal dimensions to be studied in the laboratory. (VC)

  3. 42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... fume, calculated as lead (Pb), per cubic meter of air. (d) The fume will be generated by impinging an..., which is analyzed and calculated as lead (Pb), shall not exceed 1.5 milligrams of lead for a...

  4. 42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Efficiency Respirators and Combination Gas Masks § 84.1146 Lead fume test for dust, fume, and mist... oxygen-gas flame on molten lead. (e) Samples of the test suspension will be taken during each test...

  5. 42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Efficiency Respirators and Combination Gas Masks § 84.1146 Lead fume test for dust, fume, and mist... oxygen-gas flame on molten lead. (e) Samples of the test suspension will be taken during each test...

  6. 42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Efficiency Respirators and Combination Gas Masks § 84.1146 Lead fume test for dust, fume, and mist... oxygen-gas flame on molten lead. (e) Samples of the test suspension will be taken during each test...

  7. 42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Efficiency Respirators and Combination Gas Masks § 84.1146 Lead fume test for dust, fume, and mist... oxygen-gas flame on molten lead. (e) Samples of the test suspension will be taken during each test...

  8. Removal of formaldehyde and xylene fumes from histopathology laboratories: a functional approach to the design of extraction systems.

    PubMed Central

    Edwards, F P; Campbell, A R

    1984-01-01

    There have been many reports of the relative hazards of formaldehyde, xylene, and hot paraffin wax fumes in pathology laboratories. In contrast, there have been comparatively few describing efficient extraction systems for their removal. When the opportunity presented to design a new laboratory the efficient removal of these fumes was given a high priority. In designing the extraction systems described consideration was given to the physical properties of the fumes and the degree of freedom of use of the bench, with the object of achieving sub-threshold limit values for each area of exposure. The efficiency of removal of the formaldehyde and xylene was measured using infrared spectroscopy. Images PMID:6707225

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

    PubMed

    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

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

    PubMed Central

    ANTONINI, JAMES M.; ROBERTS, JENNY R.; SCHWEGLER-BERRY, DIANE; MERCER, ROBERT R.

    2015-01-01

    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 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 2 mg 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

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

    PubMed

    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

  12. Mutagenicity of bitumen and asphalt fumes.

    PubMed

    Heikkilä, P R; Väänänen, V; Hämeilä, M; Linnainmaa, K

    2003-08-01

    The mutagenicity of asphalt fumes was tested with the Salmonella bioassays. The aim was to investigate if recycled additives modify the genotoxicity of emissions. Recycling of old asphalt is increasing, and we studied also the mutagenicity of emissions sampled during the re-use of asphalt. The composition of vapours and fumes were analysed by gas chromatography and by liquid chromatography. Bitumens containing coal fly ash (CFA) or waste plastics were heated to the paving temperatures in the laboratory. In the field, bitumen fumes were collected during paving of stone mastic asphalts (lime or CFA as a filler), remixing of stone mastic asphalt (lime or CFA as a filler), and of asphalt concrete. All the lab-generated vapour fractions were non-mutagenic. The particulate fractions were mutagenic with TA98 in the presence of the S9 activation. In addition, the lab-fumes from bitumen containing waste plastics were positive with both strains without S9. Only particulate fractions sampled in the field were tested. They were mutagenic with and without metabolic activation with both strains. The mutagenic potency of the field samples was higher than that of the lab-generated fumes without S9, and the remixing fumes were more mutagenic than the normal paving and lab-generated fumes with S9. The use of inorganic additive, CFA, did not change the mutagenicity of the fumes, whereas the organic additive, waste plastics, increased the mutagenicity of the laboratory emissions significantly. PMID:12849723

  13. Numerical simulation of laboratory fume hood airflow performance

    SciTech Connect

    Kirkpatrick, A.T.; Reither, R.

    1998-12-31

    A three-dimensional computational fluid dynamics (CFD) analysis has been used to predict airflow patterns in laboratory fume hoods. The simulation includes bypass fume hood primary operational features including the top and bottom bypasses, front airfoils, and rear-slotted baffles. All results were validated experimentally, and the simulation was found to adequately predict fume hood airflow patterns. The results indicate that fume hood flow patterns are highly dependent on inlet flow boundary conditions so that the computation must include the near field room airflow. Additionally, the study included the effects on the fume hood airflow of sash height changes, an operator positioned outside the fume hood, and equipment within the main fume hood chamber. It was shown that for conditions of a fully open sash height, a person in front of the fume hood, and an object inside the fume hood, the fume hood experiences a loss of containment of the flow.

  14. A Simple, Transparent Fume Hood

    NASA Astrophysics Data System (ADS)

    Fredericks, John

    1998-10-01

    An inexpensive transparent fume hood can be constructed from a clear-plastic two-liter soft drink bottle that is cut just above the base. A length of vacuum tubing is secured to the opening of the bottle using black electrical tape. The tubing is then connected to a water aspirator. Beakers or flasks easily fit inside the bottle, and the bottle may be secured with a clamp and ring stand for added stability. This device has been used to collect the noxious NO2 gas generated from the reaction of copper metal with nitric acid. It also may be used in the collection of other gases. It should not be used to collect gases that are not water-soluble or in experiments that involve open flames.

  15. Cables and fire hazards

    NASA Technical Reports Server (NTRS)

    Zanelli, C.; Philbrick, S.; Beretta, G.

    1986-01-01

    Besides describing the experiments conducted to develop a nonflammable cable, this article discusses several considerations regarding other hazards which might result from cable fires, particularly the toxicity and opacity of the fumes emitted by the burning cable. In addition, this article examines the effects of using the Oxygen Index as a gauge of quality control during manufacture.

  16. Design for a Miniature Portable Fume Hood.

    ERIC Educational Resources Information Center

    Bailey, Ronald A.; Wait, Samuel C., Jr.

    1999-01-01

    Describes the design of undergraduate chemical laboratory fume hoods. Proves that folding the sides and top permit the hood and its duct hose to be stored in a standard 18-inch-wide laboratory cabinet. (WRM)

  17. Identification of carcinogens in cooking oil fumes.

    PubMed

    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 (P<0.05) and the average reduction in percentage was 75%. The other identified PAHs were undetected. These results indicated that exposure to cooking oil fumes could possibly increase exposure to PAHs, which may be linked to an increased risk of lung cancer. The potential carcinogenic exposure could be reduced by placing table-edged fume extractors near cooking pots. PMID:10361022

  18. Profiling mild steel welding processes to reduce fume emissions and costs in the workplace.

    PubMed

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

    2014-05-01

    To provide quantitative information to choose the best welding processes for minimizing workplace emissions, nine gas metal arc welding (GMAW) processes for mild steel were assessed for fume generation rates, normalized fume generation rates (milligram fume per gram of electrode consumed), and normalized generation rates for elemental manganese, nickel, and iron. Shielded metal arc welding (SMAW) and flux-cored arc-welding (FCAW) processes were also profiled. The fumes were collected quantitatively in an American Welding Society-type fume chamber and weighed, recovered, homogenized, and analyzed by inductively coupled atomic emission spectroscopy for total metals. The processes included GMAW with short circuit, globular transfer, axial spray, pulsed spray, Surface Tension Transfer™, Regulated Metal Deposition™, and Cold Metal Transfer™ (CMT) modes. Flux-cored welding was gas shielded, and SMAW was a single rod type. Results indicate a wide range of fume emission factors for the process variations studied. Fume emission rates per gram of electrode consumed were highest for SMAW (~13 mg fume g(-1) electrode) and lowest for GMAW processes such as pulsed spray (~1.5mg g(-1)) and CMT (~1mg g(-1)). Manganese emission rates per gram of electrode consumed ranged from 0.45 mg g(-1) (SMAW) to 0.08 mg g(-1) (CMT). Nickel emission rates were generally low and ranged from ~0.09 (GMAW short circuit) to 0.004 mg g(-1) (CMT). Iron emission rates ranged from 3.7 (spray-mode GMAW) to 0.49 mg g(-1) (CMT). The processes studied have significantly different costs, and cost factors are presented based on a case study to allow comparisons between processes in specific cost categories. Costs per linear meter of weld were $31.07 (SMAW), $12.37 (GMAW short circuit), and $10.89 (FCAW). Although no single process is the best for minimizing fume emissions and costs while satisfying the weld requirements, there are several processes that can minimize emissions. This study provides

  19. Profiling Mild Steel Welding Processes to Reduce Fume Emissions and Costs in the Workplace

    PubMed Central

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

    2015-01-01

    To provide quantitative information to choose the best welding processes for minimizing workplace emissions, nine gas metal arc welding (GMAW) processes for mild steel were assessed for fume generation rates, normalized fume generation rates (milligram fume per gram of electrode consumed), and normalized generation rates for elemental manganese, nickel, and iron. Shielded metal arc welding (SMAW) and flux-cored arc-welding (FCAW) processes were also profiled. The fumes were collected quantitatively in an American Welding Society-type fume chamber and weighed, recovered, homogenized, and analyzed by inductively coupled atomic emission spectroscopy for total metals. The processes included GMAW with short circuit, globular transfer, axial spray, pulsed spray, Surface Tension Transfer™, Regulated Metal Deposition™, and Cold Metal Transfer™ (CMT) modes. Flux-cored welding was gas shielded, and SMAW was a single rod type. Results indicate a wide range of fume emission factors for the process variations studied. Fume emission rates per gram of electrode consumed were highest for SMAW (~13 mg fume g−1 electrode) and lowest for GMAW processes such as pulsed spray (~1.5 mg g−1) and CMT (~1 mg g−1). Manganese emission rates per gram of electrode consumed ranged from 0.45 mg g−1 (SMAW) to 0.08 mg g−1 (CMT). Nickel emission rates were generally low and ranged from ~0.09 (GMAW short circuit) to 0.004 mg g−1 (CMT). Iron emission rates ranged from 3.7 (spray-mode GMAW) to 0.49 mg g−1 (CMT). The processes studied have significantly different costs, and cost factors are presented based on a case study to allow comparisons between processes in specific cost categories. Costs per linear meter of weld were $31.07 (SMAW), $12.37 (GMAW short circuit), and $10.89 (FCAW). Although no single process is the best for minimizing fume emissions and costs while satisfying the weld requirements, there are several processes that can minimize emissions. This study provides

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

    SciTech Connect

    Li, Xinying; Chen, Quanyuan; Zhou, Yasu; Tyrer, Mark; Yu, Yang

    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.

  1. Asphalt fume dermal carcinogenicity potential: I. dermal carcinogenicity evaluation of asphalt (bitumen) fume condensates.

    PubMed

    Clark, Charles R; Burnett, Donald M; Parker, Craig M; Arp, Earl W; Swanson, Mark S; Minsavage, Gary D; Kriech, Anthony J; Osborn, Linda V; Freeman, James J; Barter, Robert A; Newton, Paul E; Beazley, Shelley L; Stewart, Christopher W

    2011-10-01

    Asphalt (bitumen) fume condensates collected from the headspace above paving and Type III built up roofing asphalt (BURA) tanks were evaluated in two-year dermal carcinogenicity assays in male C3H/HeNCrl mice. A third sample was generated from the BURA using a NIOSH laboratory generation method. Similar to earlier NIOSH studies, the BURA fume condensates were applied dermally in mineral oil twice per week; the paving sample was applied 7 days/week for a total weekly dose of 50 mg/wk in both studies. A single benign papilloma was observed in a group of 80 mice exposed to paving fume condensate at the end of the two-year study and only mild skin irritation was observed. The lab generated BURA fume condensate resulted in statistically significant (P<0.0001) increases in squamous cell carcinomas (35 animals or 55% of animals at risk). The field-matched BURA condensate showed a weaker but significant (P=0.0063) increase (8 carcinomas or 13% of animals) and a longer average latency (90 weeks vs. 76 for the lab fume). Significant irritation was observed in both BURA condensates. It is concluded that the paving fume condensate was not carcinogenic under the test conditions and that the field-matched BURA fume condensate produced a weak tumor response compared to the lab generated sample. PMID:21524677

  2. Combustion fume structure and dynamics. Final report

    SciTech Connect

    Flagan, R.C.

    1995-06-29

    An investigation of the fundamental physical processes that govern the structures of fume particles that are produced from the vapor phase in a wide range of high temperature systems has been conducted. The key objective of this study has been to develop models of the evolution of fine particles of refractory materials that are produced from the vapor phase, with particular emphasis on those processes that govern the evolution of ash fumes produced from volatilized mineral matter during coal combustion. To accomplish this goal, the study has included investigations of a number of fundamental aspects of pyrogenous fumes: Structural characterization of agglomerate particles in terms of fractal structure parameters; the relationship between the structures of agglomerate particles and the aerodynamic drag forces they experience; coagulation kinetics of fractal-like particles; sintering of aerosol agglomerates past the early stage of neck formation and incorporating the simultaneous influences of several transport mechanisms.

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

    PubMed

    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

  4. MIXING PHENOMENA IN INDUSTRIAL FUME AFTERBURNER SYSTEMS

    EPA Science Inventory

    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...

  5. Persistence of Change: Fume Hood Campaign Lessons

    ERIC Educational Resources Information Center

    Feder, Elah; Robinson, Jennifer; Wakefield, Sarah

    2012-01-01

    Purpose: Sustainability initiatives typically operate for a limited time period, but it is often unclear whether they have lasting effects. The purpose of this paper is to examine a laboratory fume hood campaign, in order to identify factors that might contribute or detract from long-term change persistence. Design/methodology/approach: The…

  6. Hazardous Fluids Compatibility Test Apparatus

    NASA Technical Reports Server (NTRS)

    Flores, Frank; Daniel, James

    1995-01-01

    Document describes test apparatus designed to hold test tubes containing hazardous fluids such as hydrazine, nitrogen tetroxide, or ammonia. Test tube suspended over water bath or other solution or mixture. Control of test sample performed by one-hand operation within fume hood or glove box. System adaptable for automated control of lowering and raising of test samples.

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

    PubMed Central

    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 VI). Total Cr content of fumes varied from 0.1 to 7.4%. The distribution of particular Cr compounds was: 52.6% soluble Cr (including 50.7% Cr VI), 65.5% total Cr VI, and 11.4% insoluble Cr VI. The results obtained indicate that MMA/SS welding is a process that could be highly hazardous to human health. Evaluation of occupational exposure has shown that MMA/SS welders may exceed the admissible concentrations of soluble and insoluble Cr VI forms as well as of Mn and Ni. In the plants investigated the sum of the ratios of concentrations of particular welding fumes in the breathing zone of welders exceeded corresponding maximum allowable concentration values by 24 times (including 17 times for total Cr VI). Due to the variety and changeability of particular parameters occurring in the working environment, the composition of MMA/SS welding fumes (in the welder's breathing zone) is so variable that it is not possible to assess the exposure by means of one universal exposure indicator (maximum additive hygienic limit value). The evaluation should be based on the results of measurements of concentrations of particular elements in welding fumes. PMID:8457491

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

    PubMed

    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

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

    PubMed Central

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

    2016-01-01

    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

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

    PubMed

    Li, Xinying; Chen, Quanyuan; Zhou, Yasu; Tyrer, Mark; Yu, Yang

    2014-12-01

    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 ((27)Al and (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. PMID:25277825

  11. Rapid Detection of Transition Metals in Welding Fumes Using Paper-Based Analytical Devices

    PubMed Central

    Volckens, John

    2014-01-01

    Metals in particulate matter (PM) are considered a driving factor for many pathologies. Despite the hazards associated with particulate metals, personal exposures for at-risk workers are rarely assessed due to the cost and effort associated with monitoring. As a result, routine exposure assessments are performed for only a small fraction of the exposed workforce. The objective of this research was to evaluate a relatively new technology, microfluidic paper-based analytical devices (µPADs), for measuring the metals content in welding fumes. Fumes from three common welding techniques (shielded metal arc, metal inert gas, and tungsten inert gas welding) were sampled in two welding shops. Concentrations of acid-extractable Fe, Cu, Ni, and Cr were measured and independently verified using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Results from the µPAD sensors agreed well with ICP-OES analysis; the two methods gave statistically similar results in >80% of the samples analyzed. Analytical costs for the µPAD technique were ~50 times lower than market-rate costs with ICP-OES. Further, the µPAD method was capable of providing same-day results (as opposed several weeks for ICP laboratory analysis). Results of this work suggest that µPAD sensors are a viable, yet inexpensive alternative to traditional analytic methods for transition metals in welding fume PM. These sensors have potential to enable substantially higher levels of hazard surveillance for a given resource cost, especially in resource-limited environments. PMID:24515892

  12. Rapid detection of transition metals in welding fumes using paper-based analytical devices.

    PubMed

    Cate, David M; Nanthasurasak, Pavisara; Riwkulkajorn, Pornpak; L'Orange, Christian; Henry, Charles S; Volckens, John

    2014-05-01

    Metals in particulate matter (PM) are considered a driving factor for many pathologies. Despite the hazards associated with particulate metals, personal exposures for at-risk workers are rarely assessed due to the cost and effort associated with monitoring. As a result, routine exposure assessments are performed for only a small fraction of the exposed workforce. The objective of this research was to evaluate a relatively new technology, microfluidic paper-based analytical devices (µPADs), for measuring the metals content in welding fumes. Fumes from three common welding techniques (shielded metal arc, metal inert gas, and tungsten inert gas welding) were sampled in two welding shops. Concentrations of acid-extractable Fe, Cu, Ni, and Cr were measured and independently verified using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Results from the µPAD sensors agreed well with ICP-OES analysis; the two methods gave statistically similar results in >80% of the samples analyzed. Analytical costs for the µPAD technique were ~50 times lower than market-rate costs with ICP-OES. Further, the µPAD method was capable of providing same-day results (as opposed several weeks for ICP laboratory analysis). Results of this work suggest that µPAD sensors are a viable, yet inexpensive alternative to traditional analytic methods for transition metals in welding fume PM. These sensors have potential to enable substantially higher levels of hazard surveillance for a given resource cost, especially in resource-limited environments. PMID:24515892

  13. Identification of sulfur fumed Pinelliae Rhizoma using an electronic nose

    PubMed Central

    Zhou, Xia; Wan, Jun; Chu, Liang; Liu, Wengang; Jing, Yafeng; Wu, Chunjie

    2014-01-01

    Background: Pinelliae Rhizoma is a commonly used Chinese herb which will change brown during the natural drying process. However, sulfur fumed Pinelliae Rhizoma will get a better appearance than naturally dried one. Sulfur fumed Pinelliae Rhizoma is potentially toxical due to sulfur dioxide and sulfites formed during the fuming procedures. The odor components in sulfur fumed Pinelliae Rhizoma is complex. At present, there is no analytical method available to determine sulfur fumed Pinelliae Rhizoma simply and rapidly. To ensure medication safety, it is highly desirable to have an effective and simple method to identify sulfur fumed Pinelliae Rhizoma. Materials and Methods: This paper presents a novel approach using an electronic nose based on metal oxide sensors to identify whether Pinelliae Rhizoma was fumed with sulfur, and to predict the fuming degree of Pinelliae Rhizoma. Multivariate statistical methods such as principal components analysis (PCA), discriminant factorial analysis (DFA) and partial least squares (PLS) were used for data analyzing and identification. The use of the electronic nose to discriminate between different fuming degrees Pinelliae Rhizoma and naturally dried Pinelliae Rhizoma was demonstrated. Results: The electronic nose was also successfully applied to identify unknown samples including sulfur fumed samples and naturally dried samples, high recognition value was obtained. Quantitative analysis of fuming degree of Pinelliae Rhizoma was also demonstrated. The method developed is simple and fast, which provides a new quality control method of Chinese herbs from the aspect of odor. Conclusion: It has shown that this electronic nose based metal oxide sensor is sensitive to sulfur and sulfides. We suggest that it can serve as a supportive method to detect residual sulfur and sulfides. PMID:24914293

  14. 13. View of interior, north wall featuring fume hood, facing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. View of interior, north wall featuring fume hood, facing north (Note: B/W scale on fume hood is in 1/2 ft increments) - Nevada Test Site, Reactor Maintenance & Disassembly Complex, Junior Hot Cell, Jackass Flats, Area 25, South of intersection of Roads F & G, Mercury, Nye County, NV

  15. A Low-Cost, Effective, Fumes Exhaust System.

    ERIC Educational Resources Information Center

    Jacobs, C. O.

    1979-01-01

    Discusses the importance of avoiding welding fumes. The sources of these fumes are presented in a table. Criticizes currently used ventilation systems and reviews the Occupational Safety and Health Act requirements. Describes a low-cost exhaust system developed for agricultural mechanics laboratories. (LRA)

  16. A review of published quantitative experimental studies on factors affecting laboratory fume hood performance.

    PubMed

    Ahn, Kwangseog; Woskie, Susan; DiBerardinis, Louis; Ellenbecker, Michael

    2008-11-01

    This study attempted to identify the important factors that affect the performance of a laboratory fume hood and the relationship between the factors and hood performance under various conditions by analyzing and generalizing the results from other studies that quantitatively investigated fume hood performance. A literature search identified 43 studies that were published from 1966 to 2006. For each of those studies, information on the type of test methods used, the factors investigated, and the findings were recorded and summarized. Among the 43 quantitative experimental studies, 21 comparable studies were selected, and then a meta-analysis of the comparable studies was conducted. The exposure concentration variable from the resulting 617 independent test conditions was dichotomized into acceptable or unacceptable using the control level of 0.1 ppm tracer gas. Regression analysis using Cox proportional hazards models provided hood failure ratios for potential exposure determinants. The variables that were found to be statistically significant were the presence of a mannequin/human subject, the distance between a source and breathing zone, and the height of sash opening. In summary, performance of laboratory fume hoods was affected mainly by the presence of a mannequin/human subject, distance between a source and breathing zone, and height of sash opening. Presence of a mannequin/human subject in front of the hood adversely affects hood performance. Worker exposures to air contaminants can be greatly reduced by increasing the distance between the contaminant source and breathing zone and by reducing the height of sash opening. Many other factors can also affect hood performance. Checking face velocity by itself is unlikely to be sufficient in evaluating hood performance properly. An evaluation of the performance of a laboratory fume hood should be performed with a human subject or a mannequin in front of the hood and should address the effects of the activities

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

    SciTech Connect

    Gate, Laurent . E-mail: laurent.gate@inrs.fr; Langlais, Cristina; Micillino, Jean-Claude; Nunge, Herve; Bottin, Marie-Claire; Wrobel, Richard; Binet, Stephane

    2006-08-15

    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 {sup o}C) 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.

  18. [Analysis on oil fume particles in catering industry cooking emission].

    PubMed

    Tan, De-Sheng; Kuang, Yuan-Cheng; Liu, Xin; Dai, Fei-Hong

    2012-06-01

    By measuring the particulate matter of oil fume which is over 10 microm or below 10 microm separately and using microradiography and Electrical Low Pressure Impactor (ELPI), it is found out the distributing characteristic of oil fume particles in catering industry cooking emission. The result shows that the diameter of the oil fume particles which was sedimentated in the kitchen is between 10-400 microm, the concentration peak value is between 10-100 microm. The diameter of oil fume aerosol is mostly smaller than 1 microm, while the concentration peak value is between 0.063-0.109 microm. In addition, the mass concentration peak value is between 6.560-9.990 microm. Through the analysis to the physical characteristics of oil fume from catering industry cooking emissions, the eigenvalue of the oil fume has been found and the feature matter for monitoring the oil fume has been discovered to provide a reasonable standard for controlling and monitoring the catering industry cooking emission. PMID:22946182

  19. Effects of doorsill jet injection on fume cupboard containment.

    PubMed

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

    2008-10-01

    The flow separation and its accompanied recirculation induced when the airflow passes over the inappropriately designed doorsill of a chemical fume cupboard are the key factors which would lead to deterioration of the cupboard performance. In order to alleviate the contaminant leakage of the fume cupboard induced by inherent aerodynamic deficiency, a technique using doorsill jet injection is developed and validated. A planar jet is ejected upward through a slot located across the inner surface of the doorsill of a full-scale, transparent fume cupboard and is ejected upward. The laser-light-sheet-assisted smoke flow visualization is performed to explore the physical mechanism of changing and controlling the flow structure. It is found that the upward injected jet is curved by the airflow drawn into the sash opening and forms a layer of clean air which can isolate the contaminant and alleviate the diffusion through the recirculating vortex on the doorsill, if the jet velocity is properly adjusted. The tracer gas concentration measurements present extraordinarily satisfactory results--the order of magnitude of the leakage of tracer gas near the doorsill may be reduced from original levels of approximately 10(2) to approximately 10(-2) p.p.m. Except for the experimental fume cupboard used for development of technique, two commercial fume cupboards are employed for verifications and comparisons on the proposed method. Tests about the two modified commercial fume cupboards demonstrate good agreement to those of the model fume cupboard. PMID:18660505

  20. Hazardous fluid leak detector

    DOEpatents

    Gray, Harold E.; McLaurin, Felder M.; Ortiz, Monico; Huth, William A.

    1996-01-01

    A device or system for monitoring for the presence of leaks from a hazardous fluid is disclosed which uses two electrodes immersed in deionized water. A gas is passed through an enclosed space in which a hazardous fluid is contained. Any fumes, vapors, etc. escaping from the containment of the hazardous fluid in the enclosed space are entrained in the gas passing through the enclosed space and transported to a closed vessel containing deionized water and two electrodes partially immersed in the deionized water. The electrodes are connected in series with a power source and a signal, whereby when a sufficient number of ions enter the water from the gas being bubbled through it (indicative of a leak), the water will begin to conduct, thereby allowing current to flow through the water from one electrode to the other electrode to complete the circuit and activate the signal.

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

    PubMed

    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

  2. 10. LOOKING SOUTH IN BOP SHOP AT FUME HOOD AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. LOOKING SOUTH IN BOP SHOP AT FUME HOOD AND SPARE OXYGEN LANCES ON THE SERVICE FLOOR OF THE FURNACE AISLE. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  3. 4. INTERIOR VIEW OF CHEMISTRY LAB LOOKING SOUTHEAST; NOTE FUME ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. INTERIOR VIEW OF CHEMISTRY LAB LOOKING SOUTHEAST; NOTE FUME EXHAUST HOOD AT LEFT & ORIGINAL CEILING FIXTURE - Fort McCoy, Building No. T-1033, North side of South Tenth Avenue, Block 10, Sparta, Monroe County, WI

  4. In vitro RPM fibrogenic potential assay of welding fumes.

    PubMed Central

    Stern, R M; Pigott, G H

    1983-01-01

    The fibrogenic potential of 11 different welding fumes and metallic aerosols, considered to be reference standard surrogates for the commonly used welding technologies and applications responsible for 70% of welders exposure, is screened by using the rat peritoneal macrophage (RPM) in vitro bioassay. Only one class of fumes, that from the manual metal are welding of stainless steel, shows distinct fibrogenic potential. This fume, however, is not common to more than four or five of the heretofore 90 cases of pulmonary fibrosis reported among welders. Thus, although insoluble Cr(VI) is probably the active fibrogen in stainless steel fumes, an etiological factor common to all fibrogenic welding exposures must be sought; it is tentatively proposed to be NO chi, a potent experimental in vivo fibrogen copiously produced by certain welding processes and ubiquitous at low concentrations in the welding environment. PMID:6641657

  5. Analysis of polycyclic aromatic hydrocarbons in cooking oil fumes.

    PubMed

    Li, S; Pan, D; Wang, G

    1994-01-01

    Various samples of cooking oil fumes were analyzed to an effort to study the relationship between the high incidence of pulmonary adenocarcinoma in Chinese women and cooking oil fumes in the kitchen. Polycyclic aromatic hydrocarbons (PAHs) in samples of cooking oil fumes were extracted, chromatographed, and measured by fluorescence spectrophotometer. The samples included oil fumes from three commercial cooking oils and fumes from three catering shops. All samples contained benzo(a)pyrene (BaP) and dibenzo (a,h)anthracene (DBahA). In addition, the concentration of DBahA was 5.7 to 22.8 times higher than that of BaP in the fume samples. Concentrations of BaP and DBahA were, respectively, 0.463 and 5.736 micrograms/g in refined vegetable oil, 0.341 and 3.725 micrograms/g in soybean oil, and 0.305 and 4.565 micrograms/g in vegetable oil. Investigation of PAH concentrations at three catering shops showed that the level of BaP at a Youtiao (deep-fried twisted dough sticks) shop was 4.18 micrograms/100 m3, 2.28 micrograms/100 m3 at a Seqenma (candied fritters) workshop, and 0.49 micrograms/100 m3 at a kitchen of a restaurant; concentrations of DBahA were 33.80, 14.41, and 3.03 micrograms/100 m3, respectively. The high concentration of carcinogens, such as BaP and DBahA, in cooking oil fumes might help explain why Chinese women, who spend more time exposed to cooking oil fumes than men, have a high incidence of pulmonary adenocarcinoma. PMID:8161241

  6. Decreasing biotoxicity of fume particles produced in welding process.

    PubMed

    Yu, Kuei-Min; Topham, Nathan; Wang, Jun; Kalivoda, Mark; Tseng, Yiider; Wu, Chang-Yu; Lee, Wen-Jhy; Cho, Kuk

    2011-01-30

    Welding fumes contain heavy metals, such as chromium, manganese, and nickel, which cause respiratory diseases and cancer. In this study, a SiO(2) 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 SiO(2) 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 SiO(2)-coated agglomerates is higher than in baseline agglomerates. In addition, Escherichia coli (E. coli) exposed to different concentrations of pure SiO(2) particles generated from the arc welding process exhibits similar responses, suggesting that SiO(2) 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% SiO(2) precursor additives were 823, 1605, and 1800 mg/L, respectively. Taken together, these results suggest that using SiO(2) precursors as an additive to arc welding shielding gas can effectively reduce the biotoxicity of welding fume. PMID:21030147

  7. Design considerations for fume hoods for process plants.

    PubMed

    Goodfellow, H D; Bender, M

    1980-07-01

    Proper design of fume hoods is a necessary requisite for a clean working environment for many industrial processes. Until recently, the design of these hoods has been rather a trial and error approach and not based on sound engineering design principles. Hatch Associates have developed and applied new techniques to establish hood parameters for different industrail processes. The paper reviews the developed techniques and illustrates practical application of these techniques to the solving of difficult and comples fume hood design and operating performance problems. The scope of the paper covers the following subject areas: definitions and general considerations: evaluation of volume and heat flow rates for emission sources; local capture of process emissions; remote capture of process emissions and case studies of fume hood applications. The purpose of the paper is to detail a coherent approach in the analysis of emission problems which will result in the development of an efficient design of a fume capture hood. An efficient fume hood can provide a safe working place as well as a clean external environment. Although the techniques can be applied to smaller sources, the case studies which will be examined will be for fume hoods in the flow design range of 50 000 CFM to +1 000 000 CFM. PMID:7415967

  8. Metal fume fever among galvanized welders.

    PubMed

    Wardhana; Datau, E A

    2014-07-01

    The metal fume fever (MFF) is an inhalation fever syndrome in welders of galvanized steel, who join and cut metal parts using flame or electric arc and other sources of heat. Inhalation of certain freshly formed metal oxides produced from welding process can cause MFF as an acute self-limiting flulike illness. The most common cause of MFF is the inhalation of zinc oxide (ZnO). The inhalation of ZnO particles can provoke a number of clinical responses of which accompanied by changes in composition of bronchoalveolar lavage (BAL) fluid, including early increase in pro-inflammatory cytokines, inflammatory marker, and recruitment of inflammatory cells in the lungs. The MFF is characterized by fever, cough, sputing, wheezing, chest tightness, fatique, chills, fever, myalgias, cough, dyspnea, leukocytosis with a left shift, thirst, metallic taste, and salivations. The diagnosis of MFF diagnosis is based on clinical finding and occupational history. The symptoms resolved spontaneously. The treatment of MFF is entirely symptomatic, no specific treatment is indicated for MFF. The mainstay of management of MFF is prevention of sub-sequent exposure to harmful metals. Including public and physician awareness of MFF may help to reduce the occurrence of the disease. PMID:25348190

  9. Numerical analysis of fume formation mechanism in arc welding

    NASA Astrophysics Data System (ADS)

    Tashiro, Shinichi; Zeniya, Tasuku; Yamamoto, Kentaro; Tanaka, Manabu; Nakata, Kazuhiro; Murphy, Anthony B.; Yamamoto, Eri; Yamazaki, Kei; Suzuki, Keiichi

    2010-11-01

    In order to clarify the fume formation mechanism in arc welding, a quantitative investigation based on the knowledge of interaction among the electrode, arc and weld pool is indispensable. A fume formation model consisting of a heterogeneous condensation model, a homogeneous nucleation model and a coagulation model has been developed and coupled with the GTA or GMA welding model. A series of processes from evaporation of metal vapour to fume formation from the metal vapour was totally investigated by employing this simulation model. The aim of this paper is to visualize the fume formation process and clarify the fume formation mechanism theoretically through a numerical analysis. Furthermore, the reliability of the simulation model was also evaluated through a comparison of the simulation result with the experimental result. As a result, it was found that the size of the secondary particles consisting of small particles with a size of several tens of nanometres reached 300 nm at maximum and the secondary particle was in a U-shaped chain form in helium GTA welding. Furthermore, it was also clarified that most part of the fume was produced in the downstream region of the arc originating from the metal vapour evaporated mainly from the droplet in argon GMA welding. The fume was constituted by particles with a size of several tens of nanometres and had similar characteristics to that of GTA welding. On the other hand, if the metal transfer becomes unstable and the metal vapour near the droplet diffuses directly towards the surroundings of the arc not getting into the plasma flow, the size of the particles reaches several hundred nanometres.

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

    PubMed

    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 < 1 nm) and mesopores (1 < R < 25 nm) to the pore volume but contribution of macropores (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. Environmental exposure to cooking oil fumes and cervical intraepithelial neoplasm.

    PubMed

    Wu, Ming-Tsang; Lee, Li-Hung; Ho, Chi-Kung; Wu, Su-Chu; Lin, Long-Yau; Cheng, Bi-Hua; Liu, Chia-Ling; Yang, Chun-Yuh; Tsai, Hsiu-Ting; Wu, Trong-Neng

    2004-01-01

    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 (> or =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

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

    SciTech Connect

    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.

  13. 42 CFR 84.1149 - Airflow resistance tests; all dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Airflow resistance tests; all dust, fume, and mist... RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators and Combination Gas Masks § 84.1149 Airflow resistance tests; all dust, fume, and...

  14. 42 CFR 84.1140 - Dust, fume, and mist respirators; performance requirements; general.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Dust, fume, and mist respirators; performance... PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators and Combination Gas Masks § 84.1140 Dust, fume, and mist respirators; performance...

  15. Exposure to inhalable, respirable, and ultrafine particles in welding fume.

    PubMed

    Lehnert, Martin; Pesch, Beate; Lotz, Anne; Pelzer, Johannes; Kendzia, Benjamin; Gawrych, Katarzyna; Heinze, Evelyn; Van Gelder, Rainer; Punkenburg, Ewald; Weiss, Tobias; Mattenklott, Markus; Hahn, Jens-Uwe; Möhlmann, Carsten; Berges, Markus; Hartwig, Andrea; Brüning, Thomas

    2012-07-01

    This investigation aims to explore determinants of exposure to particle size-specific welding fume. Area sampling of ultrafine particles (UFP) was performed at 33 worksites in parallel with the collection of respirable particles. Personal sampling of respirable and inhalable particles was carried out in the breathing zone of 241 welders. Median mass concentrations were 2.48 mg m(-3) for inhalable and 1.29 mg m(-3) for respirable particles when excluding 26 users of powered air-purifying respirators (PAPRs). Mass concentrations were highest when flux-cored arc welding (FCAW) with gas was applied (median of inhalable particles: 11.6 mg m(-3)). Measurements of particles were frequently below the limit of detection (LOD), especially inside PAPRs or during tungsten inert gas welding (TIG). However, TIG generated a high number of small particles, including UFP. We imputed measurements fume. Concentrations were mainly predicted by the welding process and were significantly higher when local exhaust ventilation (LEV) was inefficient or when welding was performed in confined spaces. Substitution of high-emission techniques like FCAW, efficient LEV, and using PAPRs where applicable can reduce exposure to welding fume. However, harmonizing the different exposure metrics for UFP (as particle counts) and for the respirable or inhalable fraction of the welding fume (expressed as their mass) remains challenging. PMID:22539559

  16. 2. In the foreground is the fan which removed fumes ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. In the foreground is the fan which removed fumes from the galvanizing area in building #8. In the background are the waste treatment tanks for the acids and alkali used in the zinc-electro-plating process. - American Chain & Cable Company, East Princess Street (400 Block), York, York County, PA

  17. Exposure to Inhalable, Respirable, and Ultrafine Particles in Welding Fume

    PubMed Central

    Pesch, Beate

    2012-01-01

    This investigation aims to explore determinants of exposure to particle size-specific welding fume. Area sampling of ultrafine particles (UFP) was performed at 33 worksites in parallel with the collection of respirable particles. Personal sampling of respirable and inhalable particles was carried out in the breathing zone of 241 welders. Median mass concentrations were 2.48 mg m−3 for inhalable and 1.29 mg m−3 for respirable particles when excluding 26 users of powered air-purifying respirators (PAPRs). Mass concentrations were highest when flux-cored arc welding (FCAW) with gas was applied (median of inhalable particles: 11.6 mg m−3). Measurements of particles were frequently below the limit of detection (LOD), especially inside PAPRs or during tungsten inert gas welding (TIG). However, TIG generated a high number of small particles, including UFP. We imputed measurements fume. Concentrations were mainly predicted by the welding process and were significantly higher when local exhaust ventilation (LEV) was inefficient or when welding was performed in confined spaces. Substitution of high-emission techniques like FCAW, efficient LEV, and using PAPRs where applicable can reduce exposure to welding fume. However, harmonizing the different exposure metrics for UFP (as particle counts) and for the respirable or inhalable fraction of the welding fume (expressed as their mass) remains challenging. PMID:22539559

  18. Study of how sash movement affects performance of fume hoods

    SciTech Connect

    Hardwick, T.

    1997-12-31

    This study was conducted to determine how sash movements affect the performance of fume hoods. The performance of two fume hoods was studied as the sashes were moved from closed to open position at speeds of 2 ft/s, 1.5 ft/s, and 1 ft/s. The tests were conducted with fume hoods operated at both constant volume and variable air volume. The tests indicate that sash movements can disturb airflow patterns at the face of the hood and potentially affect the performance of the hood. The effect of the sash movement varied with hood type and speed of sash movement. The faster sash movements of 2 ft/s and 1.5 ft/s had a greater effect on the performance of the hoods than the slower movement of 1 ft/s. Constant-volume hoods and variable-air-volume hoods were both affected by sash movements. Constant-volume hoods set to a full open face velocity of 60 ft/min were more susceptible to the sash movement than at 100 ft/min full open face velocity. The performance of variable-air-volume hoods is affected not only by sash movement speed but also by the response time of the controller. The drop in face velocity that occurs when the sash is moved is determined by the speed of the VAV controller. The required response time for containment depends on the fume hood design and the speed of the sash movement.

  19. Fume hood performance: Face velocity variability inconsistent air volume systems

    SciTech Connect

    Volin, C.E.; Joao, R.V.; Gershey, E.L.; Reiman, J.S.; Party, E.

    1998-09-01

    A 3-year survey of 366 bench-type fume hoods in working laboratories in conventional, constant air volume settings showed that face velocities varied greatly from unit to unit and over time. Fume hoods with bypasses performed better than those without; however, even newly fabricated bypass hoods exhibited large variations. These variations were due to several factors; however, face velocities at 100 {+-} 10 ft/min at working sash heights in the range of 20 to 40 cm (8 to 16 inches) were attainable. The use of smoke showed poor containment, especially at face velocities below 85 ft/min (0.425 m/s) or above 130 ft/min (0.65 m/s) and when the hoods were obstructed by large items placed on the work surface. Auxiliary/supplemental air created unstable face velocities and poor smoke patterns. The analysis of 3 years of fume hood monitoring showed clearly the need for and importance of a maintenance program where the fume hood lower slots are cleaned and fans, ducts, dampers, and hoods are checked periodically.

  20. Metabolomic characterization of laborers exposed to welding fumes.

    PubMed

    Wang, Kuo-Ching; Kuo, Ching-Hua; Tian, Tze-Feng; Tsai, Mong-Hsun; Chiung, Yin-Mei; Hsiech, Chun-Ming; Tsai, Sung-Jeng; Wang, San-Yuan; Tsai, Dong-Ming; Huang, Chiang-Ching; Tseng, Y Jane

    2012-03-19

    The complex composition of welding fumes, multiplicity of molecular targets, diverse cellular effects, and lifestyles associated with laborers vastly complicate the assessment of welding fume exposure. The urinary metabolomic profiles of 35 male welders and 16 male office workers at a Taiwanese shipyard were characterized via (1)H NMR spectroscopy and pattern recognition methods. Blood samples for the same 51 individuals were also collected, and the expression levels of the cytokines and other inflammatory markers were examined. This study dichotomized the welding exposure variable into high (welders) versus low (office workers) exposures to examine the differences of continuous outcome markers-metabolites and inflammatory markers-between the two groups. Fume particle assessments showed that welders were exposed to different concentrations of chromium, nickel, and manganese particles. Multivariate statistical analysis of urinary metabolomic patterns showed higher levels of glycine, taurine, betaine/TMAO, serine, S-sulfocysteine, hippurate, gluconate, creatinine, and acetone and lower levels of creatine among welders, while only TNF-α was significantly associated with welding fume exposure among all cytokines and other inflammatory markers measured. Of the identified metabolites, the higher levels of glycine, taurine, and betaine among welders were suspected to play some roles in modulating inflammatory and oxidative tissue injury processes. In this metabolomics experiment, we also discovered that the association of the identified metabolites with welding exposure was confounded by smoking, but not with drinking, which is a finding consistent with known modified response of inflammatory markers among smokers. Our results correspond with prior studies that utilized nonmetabolomic analytical techniques and suggest that the metabolomic profiling is an efficient method to characterize the overall effect of welding fume exposure and other confounders. PMID:22292500

  1. Hexavalent chromium content in stainless steel welding fumes is dependent on the welding process and shield gas type.

    PubMed

    Keane, Michael; Stone, Samuel; Chen, Bean; Slaven, James; Schwegler-Berry, Diane; Antonini, James

    2009-02-01

    Occupational exposure to welding fumes is a known health hazard. To isolate elements in stainless steel welding fumes with high potential for adverse health outcomes, fumes were generated using a robotic gas metal arc system, using four shield gases of varying oxygen content. The objective was to measure Cr(VI) concentrations in a broad spectrum of gas metal arc welding processes, and identify processes of exceptionally high or low Cr(VI) content. The gases used were 95% Ar/5% O(2), 98% Ar/2% O(2), 95% Ar/5%CO(2), and 75% He/25% Ar. The welder was operated in axial spray mode (Ar/O(2), Ar/CO(2)), short-circuit (SC) mode (Ar/CO(2) low voltage and He/Ar), and pulsed axial-spray mode (98% Ar/2% O(2)). Results indicate large differences in Cr(VI) in the fumes, with Ar/O(2) (Pulsed)>Ar/O(2)>Ar/CO(2)>Ar/CO(2) (SC)>He/Ar; values were 3000+/-300, 2800+/-85, 2600+/-120, 1400+/-190, and 320+/-290 ppm respectively (means +/- standard errors for 2 runs and 3 replicates per run). Respective rates of Cr(VI) generation were 1.5, 3.2, 4.4, 1.3, and 0.46 microg/min; generation rates were also calculated in terms of microg Cr(VI) per metre of wire used. The generation rates of Cr(VI) increased with increasing O(3) concentrations. Particle size measurements indicated similar distributions, but somewhat higher >0.6 microm fractions for the short-circuit mode samples. Fumes were also sampled into 2 selected size ranges, a microspatter fraction (>or=0.6 microm) and a fine (<0.6 microm) fraction; analysis indicated that Cr(VI) is primarily associated with particles <0.6 microm. The conclusion of the study is that Cr(VI) concentrations vary significantly with welding type and shield gas type, and this presents an opportunity to tailor welding practices to lessen Cr(VI) exposures in workplaces by selecting low Cr(VI)-generating processes. Short-circuit processes generated less Cr(VI) than axial-spray methods, and inert gas shielding gave lower Cr(VI) content than shielding with active

  2. Health-hazard evaluation report HETA 85-043-1760, American Crystal Sugar Company, Hillsboro, North Dakota

    SciTech Connect

    Boiano, J.M.; Almaguer, D.

    1986-12-01

    In response to a request from management of the American Crystal Sugar Company (ACSCO) and the American Federation of Grain Millers International Union, employee exposures to welding fumes during facility maintenance and to airborne contaminants during beet processing were determined at a sugar-beet mill owned by ACSCO. Exposures exceeding the most stringent environmental criteria were found for calcium carbonate and carbon monoxide in lime kiln workers and sugar dust in sugar bin workers. Beet pulp dust was considered a potential hazard based on its content of crystalline silica. Welding produced excessive exposures to total welding fumes, hexavalent chromium, nickel, iron-oxide, and calcium-oxide. Chromium and nickel posed potential cancer risks. The authors conclude that workers were overexposed to calcium carbonate, carbon monoxide, sugar dust, total welding fumes, hexavalent chromium, iron oxide, nickel, and calcium oxide fumes at this facility. The authors recommend dust containment, ventilation, respiratory protection, and correction of slipping hazards.

  3. Environmental monitoring of mutagenic/carcinogenic hazards during road paving operations with bitumens.

    PubMed

    Monarca, S; Pasquini, R; Scassellati Sforzolini, G; Savino, A; Bauleo, F A; Angeli, G

    1987-01-01

    Environmental monitoring of mutagenic/carcinogenic hazards associated with occupational exposure to bitumen fumes was performed during road paving operations. Bitumen samples were collected and analysed for polycyclic aromatic hydrocarbons (PAH) content by HPLC and for mutagenicity by the Ames test. The exposure of sixteen road workers to bitumen fumes was studied. Time-weighted average values of bitumen fumes were determined by personal samplers. PAH concentration in the air and the mutagenicity of airborne particulates were also analysed. The results showed that bitumen samples contained low levels of total PAH (microgram/g) and were not mutagenic. Environmental monitoring showed a low level of exposure to bitumen fumes, which were found to contain only trace levels of PAH and not to be mutagenic. The authors suggest that these workers' exposure to mutagenic/carcinogenic agents is low. PMID:3610339

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

    PubMed

    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

  5. Occupational hypersensitivity pneumonitis in a smelter exposed to zinc fumes

    SciTech Connect

    Ameille, J.; Brechot, J.M.; Brochard, P.; Capron, F.; Dore, M.F. )

    1992-03-01

    A smelter exposed to zinc fumes reported severe recurrent episodes of cough, dyspnea and fever. Bronchoalveolar lavage showed a marked increase in lymphocytes count with predominance of CD8 T-lymphocytes. Presence of zinc in alveolar macrophages was assessed by analytic transmission electron microscopy. This is the first case of recurrent bronchoalveolitis related to zinc exposure in which the clinical picture and BAL results indicate a probable hypersensitivity pneumonitis.

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

    NASA Astrophysics Data System (ADS)

    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.

  7. Detailed characterization of welding fumes in personal exposure samples

    NASA Astrophysics Data System (ADS)

    Quémerais, B.; Mino, James; Amin, M. R.; Golshahi, H.; Izadi, H.

    2015-05-01

    The objective of the project was to develop a method allowing for detailed characterization of welding particles including particle number concentration, size distribution, surface chemistry and chemical composition of individual particles, as well as metal concentration of various welding fumes in personal exposure samples using regular sampling equipment. A sample strategy was developed to evaluate the variation of the collection methods on mass concentration. Samples were collected with various samplers and filters at two different locations using our collection system. The first location was using a robotic welding system while the second was manual welding. Collected samples were analysed for mass concentration using gravimetryand metal concentration using ICP/OES. More advanced analysis was performed on selected filters using X-Ray Photoelectron Spectroscopy to determine surface composition of the particles, and X-Ray Diffraction to determine chemical composition of the fumes. Results showed that the robotic system had a lot of variation in space when the collection system was located close to the weld. Collection efficiency was found to be quite variable depending upon the type of filter. As well, metal concentrations in blank filters were dependent upon the type of filter with MCE presenting with the highest blank values. Results obtained with the XRD and XPS systems showed that it was possible to analyse a small of powdered welding fume sample but results on filters were not conclusive.

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

    PubMed

    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

  9. Effects of densified silica fume on microstructure and compressive strength of blended cement pastes

    SciTech Connect

    Ji Yajun; Cahyadi, Jong Herman

    2003-10-01

    Some experimental investigations on the microstructure and compressive strength development of silica fume blended cement pastes are presented in this paper. The silica fume replacement varies from 0% to 20% by weight and the water/binder ratio (w/b) is 0.4. The pore structure by mercury intrusion porosimetry (MIP), the micromorphology by scanning electron microscopy (SEM) and the compressive strength at 3, 7, 14, 28, 56 and 90 days have been studied. The test results indicate that the improvements on both microstructure and mechanical properties of hardened cement pastes by silica fume replacement are not effective due to the agglomeration of silica fume particles. The unreacted silica fume remained in cement pastes, the threshold diameter was not reduced and the increase in compressive strength was insignificant up to 28 days. It is suggested that the proper measures should be taken to disperse silica fume agglomeration to make it more effective on improving the properties of materials.

  10. A research on the radiation shielding effects of clay, silica fume and cement samples

    NASA Astrophysics Data System (ADS)

    Akbulut, Suat; Sehhatigdiri, Arvin; Eroglu, Hayrettin; Çelik, Semet

    2015-12-01

    Nowadays, as the application areas of nuclear technology increases, protection from radiation has become even more important. Especially, the importance of radiation-shielding is important for the environment and employees which are in close proximity. Clays can be used as additives for shielding the radioactive materials. In this study, the shielding properties of micronize clay-white cement, clay-silica fume, gypsum, gypsum-silica fume, cement, white cement, cement-silica fume, white cement-gypsum, white cement-silica fume, red mud-silica fume, silica fume and red mud at different energy levels were examined. Additionally, compaction and unconfined compression tests were carried out on the samples. The results of clays and other samples were compared with each other. As a result, it was found that clays, especially clay-white cement mixture were superior than other samples in radioactive shielding.

  11. Preparation and Characterization of Single Ion Conductors from High Surface Area Fumed Silica

    NASA Technical Reports Server (NTRS)

    Zhang, H.; Maitra, P.; Liu, B.; Wunder, S. L.; Lin, H.-P.; Salomon, M.; Hagedorn, Norman H. (Technical Monitor)

    2002-01-01

    Anions that can form dissociative salts with Li(+) have been prepared and covalently attached to high surface area fumed silica. When blended with polyethylene oxide (PEO), the functionalized fumed silica suppresses the crystallization of the PEO, provides dimensional stability, and serves as a single ion conductor. Since functionalized fumed silica is easily dispersed in common polar solvents, it can be incorporated in both the polymer electrolyte and the electrodes.

  12. Manganese in occupational arc welding fumes--aspects on physiochemical properties, with focus on solubility.

    PubMed

    Taube, Fabian

    2013-01-01

    Physicochemical properties, such as particle sizes, composition, and solubility of welding fumes are decisive for the bioaccessibility of manganese and thereby for the manganese cytotoxic and neurotoxic effects arising from various welding fumes. Because of the diverse results within the research on welding fume solubility, this article aims to review and discuss recent literature on physicochemical properties of gas metal arc welding, shielded metal arc welding, and flux-cored arc welding fumes, with focus on solubility properties. This article also presents a short introduction to the literature on arc welding techniques, health effects from manganese, and occupational exposure to manganese among welders. PMID:22997412

  13. Kinetics of the metal components of intratracheally instilled stainless steel welding fume suspensions in rats.

    PubMed Central

    Kalliomäki, P L; Hyvärinen, H K; Aitio, A; Lakoma, E L; Kalliomäki, K

    1986-01-01

    The kinetics of iron, chromium, nickel, and cobalt from manual metal arc and metal inert gas stainless steel welding fumes were studied. Neutron activated welding fumes, in aqueous suspensions, were instilled intratracheally into rats. The follow up continued for up to 106 days. From both fumes, approximately 10% of the injection bolus was immediately lost into the gastrointestinal tract, to be recovered in the faeces within three days. Thereafter, a pronounced difference was seen in the kinetics of the two types of fumes. After the first day, chromium, nickel, and iron were lost from the lungs with half times of about 53, 49, and 73 days after exposure to MMA/SS fumes, whereas practically no loss could be seen in the metal components of the metal inert gas welding fumes within two months. The disposition of chromium from MMA/SS fumes closely resembled that of intratracheally instilled water soluble chromates. On the other hand, the disappearance of trivalent chromium from MIS/SS fumes was considerably slower than that of the practically water insoluble chromates, or even of trivalent chromium salts. Thus the physical characteristics of the fume appreciably affect the kinetics of the clearance of chromium compounds from the lungs. PMID:3947567

  14. A Comparison of Cytotoxicity and Oxidative Stress from Welding Fumes Generated with a New Nickel-, Copper-Based Consumable versus Mild and Stainless Steel-Based Welding in RAW 264.7 Mouse Macrophages

    PubMed Central

    Badding, Melissa A.; Fix, Natalie R.; Antonini, James M.; Leonard, Stephen S.

    2014-01-01

    Welding processes that generate fumes containing toxic metals, such as hexavalent chromium (Cr(VI)), manganese (Mn), and nickel (Ni), have been implicated in lung injury, inflammation, and lung tumor promotion in animal models. While federal regulations have reduced permissible worker exposure limits to Cr(VI), this is not always practical considering that welders may work in confined spaces and exhaust ventilation may be ineffective. Thus, there has been a recent initiative to minimize the potentially hazardous components in welding materials by developing new consumables containing much less Cr(VI) and Mn. A new nickel (Ni) and copper (Cu)-based material (Ni-Cu WF) is being suggested as a safer alternative to stainless steel consumables; however, its adverse cellular effects have not been studied. This study compared the cytotoxic effects of the newly developed Ni-Cu WF with two well-characterized welding fumes, collected from gas metal arc welding using mild steel (GMA-MS) or stainless steel (GMA-SS) electrodes. RAW 264.7 mouse macrophages were exposed to the three welding fumes at two doses (50 µg/ml and 250 µg/ml) for up to 24 hours. Cell viability, reactive oxygen species (ROS) production, phagocytic function, and cytokine production were examined. The GMA-MS and GMA-SS samples were found to be more reactive in terms of ROS production compared to the Ni-Cu WF. However, the fumes from this new material were more cytotoxic, inducing cell death and mitochondrial dysfunction at a lower dose. Additionally, pre-treatment with Ni-Cu WF particles impaired the ability of cells to phagocytize E. coli, suggesting macrophage dysfunction. Thus, the toxic cellular responses to welding fumes are largely due to the metal composition. The results also suggest that reducing Cr(VI) and Mn in the generated fume by increasing the concentration of other metals (e.g., Ni, Cu) may not necessarily improve welder safety. PMID:24977413

  15. A comparison of cytotoxicity and oxidative stress from welding fumes generated with a new nickel-, copper-based consumable versus mild and stainless steel-based welding in RAW 264.7 mouse macrophages.

    PubMed

    Badding, Melissa A; Fix, Natalie R; Antonini, James M; Leonard, Stephen S

    2014-01-01

    Welding processes that generate fumes containing toxic metals, such as hexavalent chromium (Cr(VI)), manganese (Mn), and nickel (Ni), have been implicated in lung injury, inflammation, and lung tumor promotion in animal models. While federal regulations have reduced permissible worker exposure limits to Cr(VI), this is not always practical considering that welders may work in confined spaces and exhaust ventilation may be ineffective. Thus, there has been a recent initiative to minimize the potentially hazardous components in welding materials by developing new consumables containing much less Cr(VI) and Mn. A new nickel (Ni) and copper (Cu)-based material (Ni-Cu WF) is being suggested as a safer alternative to stainless steel consumables; however, its adverse cellular effects have not been studied. This study compared the cytotoxic effects of the newly developed Ni-Cu WF with two well-characterized welding fumes, collected from gas metal arc welding using mild steel (GMA-MS) or stainless steel (GMA-SS) electrodes. RAW 264.7 mouse macrophages were exposed to the three welding fumes at two doses (50 µg/ml and 250 µg/ml) for up to 24 hours. Cell viability, reactive oxygen species (ROS) production, phagocytic function, and cytokine production were examined. The GMA-MS and GMA-SS samples were found to be more reactive in terms of ROS production compared to the Ni-Cu WF. However, the fumes from this new material were more cytotoxic, inducing cell death and mitochondrial dysfunction at a lower dose. Additionally, pre-treatment with Ni-Cu WF particles impaired the ability of cells to phagocytize E. coli, suggesting macrophage dysfunction. Thus, the toxic cellular responses to welding fumes are largely due to the metal composition. The results also suggest that reducing Cr(VI) and Mn in the generated fume by increasing the concentration of other metals (e.g., Ni, Cu) may not necessarily improve welder safety. PMID:24977413

  16. [Emission Characteristics of Water-Soluble Ions in Fumes of Coal Fired Boilers in Beijing].

    PubMed

    Hu, Yue-qi; Ma, Zhao-hui; Feng, Ya-jun; Wang, Chen; Chen, Yuan-yuan; He, Ming

    2015-06-01

    Selecting coal fired boilers with typical flue gas desulfurization and dust extraction systems in Beijing as the study objects, the issues and characteristics of the water-soluble ions in fumes of coal fired boilers and theirs influence factors were analyzed and evaluated. The maximum mass concentration of total water-soluble ions in fumes of coal fired boilers in Beijing was 51.240 mg x m(-3) in the benchmark fume oxygen content, the minimum was 7.186 mg x m(-3), and the issues of the water-soluble ions were uncorrelated with the fume moisture content. SO4(2-) was the primary characteristic water-soluble ion for desulfurization reaction, and the rate of contribution of SO4(2-) in total water-soluble ions ranged from 63.8% to 81.0%. F- was another characteristic water-soluble ion in fumes of thermal power plant, and the rate of contribution of F- in total water-soluble ions ranged from 22.2% to 32.5%. The fume purification technologies significantly influenced the issues and the emission characteristics of water-soluble ions in fumes of coal fired boilers. Na+ was a characteristic water-soluble ion for the desulfurizer NaOH, NH4+ and NO3+ were characteristic for the desulfurizer NH4HCO3, and Mg2+ was characteristic for the desulfurizer MgO, but the Ca2+ emission was not increased by addition of the desulfurizer CaO or CaCO3 The concentrations of NH4+ and NO3- in fumes of thermal power plant were lower than those in fumes of industrial or heating coal fired boilers. The form of water-soluble ions was significantly correlated with fume temperature. The most water-soluble ions were in superfine state at higher fume temperature and were not easily captured by the filter membrane. PMID:26387296

  17. Efficiency of different respiratory protective devices for removal of particulate and gaseous reactive oxygen species from welding fumes.

    PubMed

    Chen, Hsiu-Ling; Chung, Shih-Hsiang; Jhuo, Ming-Lin

    2013-01-01

    Ultraviolet (UV) light inherent to welding processes generates ozone (O(3)) with subsequent formation of reactive oxygen species (ROS) through photochemical reactions when UV light is present with O(3). This study aimed to determine the performance of filters used as respiratory protective devices by welding personnel to simultaneously mitigate particulate and gaseous inhalation hazards. Four respiratory protective devices were selected for this study, including a surgical facemask, a cotton-fabric facemask, an activated-carbon facemask, and an N95 respirator. The removal efficiencies for the particulates in welding fumes were all above 98%. For particulate-phase ROS, the removal efficiencies of the different respiratory protective devices ranged from 83.5% to 94.1%; however, the removal efficiencies for gaseous ROS were only 1.3% (active carbon facemask) to 21.1% (N95 respirator). The data indicated that the respiratory protective devices commercially available cannot block the passage of the gas-phase ROS found in welding fumes. PMID:23428060

  18. Infant leukemia and paternal exposure to motor vehicle exhaust fumes

    SciTech Connect

    Vianna, N.J.; Kovasznay, B.; Polan, A.; Ju, C.

    1984-09-01

    The children of fathers who work in gas stations, automobile or truck repair, and aircraft maintenance appear to be at increased risk for acute leukemia during their first year of life. The odds ratio was found to be about 2.5 overall, but risk appears to be greater for female offspring. A decline in sex ratio was observed for the three decades of the study, with the lowest ratio observed from 1969 through 1978. These preliminary findings suggest that exposure to one or more of the components of exhaust fumes might be of etiologic importance for this malignancy. The limitations of this investigation are discussed.

  19. Some engineering properties of heavy concrete added silica fume

    SciTech Connect

    Akkaş, Ayşe; Başyiğit, Celalettin; Esen, Serap

    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.

  20. 42 CFR 84.1147 - Silica mist test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    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)...

  1. 42 CFR 84.1147 - Silica mist test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 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)...

  2. 42 CFR 84.1147 - Silica mist test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 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)...

  3. 42 CFR 84.1147 - Silica mist test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 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)...

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 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. Physicochemical Characterization of Simulated Welding Fume from a Spark Discharge System

    PubMed Central

    Park, Jae Hong; Mudunkotuwa, Imali A.; Kim, Jong Sung; Stanam, Aditya; Thorne, Peter S.; Grassian, Vicki H.; Peters, Thomas M.

    2014-01-01

    This study introduces spark discharge system (SDS) as a way to simulate welding fumes. The SDS was developed using welding rods as electrodes with an optional coagulation chamber. The size, morphology, composition, and concentration of the fume produced and the concentration of ozone (O3) and nitrogen oxides (NOX) were characterized. The number median diameter (NMD) and total number concentration (TNC) of fresh fume particles were ranged 10–23 nm and 3.1×107–6×107 particles/cm3, respectively. For fresh fume particles, the total mass concentration (TMC) measured gravimetrically ranged 85–760 μg/m3. The size distribution was stable over a period of 12 h. The NMD and TNC of aged fume particles were ranged 81–154 nm and 1.5×106–2.7×106 particles/cm3, respectively. The composition of the aged fume particles was dominated by Fe and O with an estimated stoichiometry between that of Fe2O3 and Fe3O4. Concentrations of O3 and NOX were ranged 0.07–2.2 ppm and 1–20 ppm, respectively. These results indicate that the SDS is capable of producing stable fumes over a long-period that are similar to actual welding fumes. This system may be useful in toxicological studies and evaluation of instrumentation. PMID:25097299

  6. 42 CFR 84.1153 - Dust, fume, mist, and smoke tests; canister bench tests; gas masks canisters containing filters...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Dust, fume, mist, and smoke tests; canister bench..., fume, mist, and smoke tests; canister bench tests; gas masks canisters containing filters; minimum requirements. (a) Gas mask canisters containing filters for protection against dusts, fumes, mists, and...

  7. 42 CFR 84.1153 - Dust, fume, mist, and smoke tests; canister bench tests; gas masks canisters containing filters...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Dust, fume, mist, and smoke tests; canister bench..., fume, mist, and smoke tests; canister bench tests; gas masks canisters containing filters; minimum requirements. (a) Gas mask canisters containing filters for protection against dusts, fumes, mists, and...

  8. 42 CFR 84.1153 - Dust, fume, mist, and smoke tests; canister bench tests; gas masks canisters containing filters...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Dust, fume, mist, and smoke tests; canister bench..., fume, mist, and smoke tests; canister bench tests; gas masks canisters containing filters; minimum requirements. (a) Gas mask canisters containing filters for protection against dusts, fumes, mists, and...

  9. 42 CFR 84.1153 - Dust, fume, mist, and smoke tests; canister bench tests; gas masks canisters containing filters...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Dust, fume, mist, and smoke tests; canister bench..., fume, mist, and smoke tests; canister bench tests; gas masks canisters containing filters; minimum requirements. (a) Gas mask canisters containing filters for protection against dusts, fumes, mists, and...

  10. A laboratory rig for studying aspects of worker exposure to bitumen fumes.

    PubMed

    Brandt, H C; de Groot, P C

    1999-01-01

    This study was performed to establish which factors related to the hot application of bitumen products are relevant to worker exposure to benzene-soluble matter (as part of the total fume emission) and to the polycyclic aromatic compound (PAH) content of bitumen fume. Because personal exposure measurements in field surveys can be influenced by many uncontrollable variables, a simple laboratory rig was developed in which bitumen fumes can be generated reproducibly under well-controlled conditions. Laboratory results were related to personal exposure measurements during asphalt paving and roofing. A quantitative relationship for predicting the laboratory fume emission was derived, with bitumen volatility and temperature the only variables. The variable part of the equation is termed the fuming index (FI). The FI correlates well with measured personal exposures in asphalt paving and in roofing and can be used to predict average personal exposures during these activities if bitumen volatility, application temperature, and for paving, the asphalt type, are known. The laboratory fumes, generated at a standard temperature of 160 degrees C, are representative for fumes emitted in the temperature range relevant for asphalt paving, those generated at 250 degrees C for roofing. The PAH profiles of the fumes collected as personal samples during asphalt paving and roofing operations were similar to those of the fumes generated in the laboratory from the same bitumen and at the same temperature. Because it produces conditions representative of actual bitumen operations, this laboratory set-up is an excellent tool for assessing bitumens in terms of fuming tendency and PAH emissions/exposures. PMID:10222568

  11. Stainless steel manual metal arc welding fumes in rats.

    PubMed Central

    Kalliomäki, P L; Lakomaa, E; Kalliomäki, K; Kiilunen, M; Kivelä, R; Vaaranen, V

    1983-01-01

    Forty two male Wistar rats were exposed to manual metal arc (MMA) stainless steel (SS) welding fumes generated by an automatic welding device for "nose-only" exposure. The exposure simulated an actual MMA/SS welding environment as closely as possible. For the retention study, the duration of exposure was one hour per workday for one, two, three, of four weeks and for the clearance study four weeks. The retention and clearance of the chromium, nickel, and iron found in MMA/SS welding fumes in the rats' lungs were studied as was the distribution of the metals to other organs. Instrumental neutron activation analysis (INAA) was used for the multi-element chemical activation analyses. The concentrations of chromium and nickel in the blood and the urine were determined by atomic absorption method (AAS). The retention of exogenous iron was determined by a magnetic measuring method. The results indicated that the lungs were the target organs of soluble hexavalent chromates. The half times of lung clearance for Cr, Ni, and Fe were 40 +/- 4 d, 20 +/- d, and 50 +/- 10 d. When the lung clearance curves are compared, the half times of Cr and Fe lung clearance are similar but nickel disappears faster. The distribution and clearance patterns of chromium to other organs differ from those obtained after single intravenous or intratracheal injections of alkaline chromates. PMID:6830723

  12. Evaluation of one-step luminescent cyanoacrylate fuming.

    PubMed

    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

  13. Urinary excretion of mutagens, thioethers and D-glucaric acid in workers exposed to bitumen fumes.

    PubMed

    Pasquini, R; Monarca, S; Scassellati Sforzolini, G; Savino, A; Bauleo, F A; Angeli, G

    1989-01-01

    The authors carried out biological monitoring of the mutagenic/carcinogenic hazards associated with exposure to bitumen fumes during paving operations, analysing some biological parameters in the urine of a group of exposed workers. The urine samples were studied for mutagenicity by the Ames test and for thioethers concentration. D-Glucaric acid urine excretion was also determined to investigate the enzymatic induction potential of bitumens. Even though, in a previous environmental monitoring phase, a low content of mutagenic/carcinogenic compounds was found in bitumen and air samples, urinary mutagenicity data of exposed workers were statistically higher than those of a group of unexposed subjects. The urinary mutagenicity increased further if exposure to bitumens was associated with cigarette smoking. Thioethers were higher only in subjects exposed simultaneously to bitumens and cigarettes. D-Glucaric acid excretion did not increase significantly. The authors think that this type of coupled environmental and biological monitoring is a valid tool for a better evaluation of the mutagenic/carcinogenic exposure to bitumens or similar complex mixtures. PMID:2707871

  14. Double shroud delivery of silica precursor for reducing hexavalent chromium in welding fume.

    PubMed

    Wang, Jun; Kalivoda, Mark; Guan, Jianying; Theodore, Alexandros; Sharby, Jessica; Wu, Chang-Yu; Paulson, Kathleen; Es-Said, Omar

    2012-01-01

    The welding process yields a high concentration of nanoparticles loaded with hexavalent chromium (Cr(6+)), a known human carcinogen. Previous studies have demonstrated that using tetramethylsilane (TMS) as a shielding gas additive can significantly reduce the Cr(6+) concentration in welding fume particles. In this study, a novel insulated double shroud torch (IDST) was developed to further improve the reduction of airborne Cr(6+) concentration by separating the flows of the primary shielding gas and the TMS carrier gas. Welding fumes were collected from a welding chamber in the laboratory and from a fixed location near the welding arc in a welding facility. The Cr(6+) content was analyzed with ion chromatography and X-ray photoelectron spectroscopy (XPS). Results from the chamber sampling demonstrated that the addition of 3.2 ≈ 5.1% of TMS carrier gas to the primary shielding gas resulted in more than a 90% reduction of airborne Cr(6+) under all shielding gas flow rates. The XPS result confirmed complete elimination of Cr(6+) inside the amorphous silica shell. Adding 100 ≈ 1000 ppm of nitric oxide or carbon monoxide to the shielding gas could also reduce Cr(6+) concentrations up to 57% and 35%, respectively; however, these reducing agents created potential hazards from the release of unreacted agents. Results of the field test showed that the addition of 1.6% of TMS carrier gas to the primary shielding gas reduced Cr(6+) concentration to the limitation of detection (1.1 μg/m(3)). In a worst-case scenario, if TMS vapor leaked into the environment without decomposition and ventilation, the estimated TMS concentration in the condition of field sampling would be a maximum 5.7 ppm, still well below its flammability limit (1%). Based on a previously developed cost model, the use of TMS increases the general cost by 3.8%. No visual deterioration of weld quality caused by TMS was found, although further mechanical testing is necessary. PMID:23113576

  15. 78 FR 33894 - Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ... AFFAIRS Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment... members of the Armed Forces to toxic airborne chemicals and fumes caused by open burn pits. DATES: Written...: cynthia.harvey-pryor@va.gov . Please refer to ``OMB Control No. 2900-NEW, Open Burn Pit Registry...

  16. Hazardous Waste

    MedlinePlus

    ... you throw these substances away, they become hazardous waste. Some hazardous wastes come from products in our homes. Our garbage can include such hazardous wastes as old batteries, bug spray cans and paint ...

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Combustion fume structure and dynamics. Semiannual report, August 16, 1993--February 15, 1994

    SciTech Connect

    Flagan, R.C.

    1995-09-01

    During pulverized coal combustion, a fume of submicron particles is formed from the mineral matter in the parent coal. Studies of the variation in chemical composition with particle size have revealed that much of the submicron fume is formed from volatilized coal ash. The formation and evolution of the ash fume is governed by homogeneous nucleation, condensation, and coagulation. Vapors of refractory species nucleate relatively early in the combustion process. Coagulation of those fine particles results in a size distribution that is approximately log normal. More volatile species remain in the gas phase until after the nucleation has taken place. Condensation on the surfaces of both the fume and the larger residual ash particles results in the enrichment of the fine particles with volatile, A comprehensive theoretical treatment of the aerosol dynamics of pyrogenous fumes requires a number of extensions of the classical descriptions. Rigorous descriptions of the coagulation of dense, spherical particles are available, but fume particles are rarely spherical. The materials involved tend to be refractory, so high temperatures are required to achieve complete coalescence. Flame temperatures may be hot enough to melt some materials, so coalescence is not always achieved. Even with systems that can melt the particles in the primary reaction zone, coagulation during the cooling or quench process can form agglomerates. To predict the dynamics of the fumes produced when coalescence is rate limiting, the structure and dynamics of the resulting aggregates must be understood.

  19. Development of an animal model to study the potential neurotoxic effects associated with welding fume inhalation.

    PubMed

    Antonini, James M; O'Callaghan, James P; Miller, Diane B

    2006-09-01

    Serious questions have been raised regarding a possible causal association between neurological effects in welders and the presence of manganese in welding fume. An experimental model is needed that could examine the potential neurotoxic effect of manganese after pulmonary exposure to welding fume. The National Institute for Occupational Safety and Health (NIOSH) has recently finished construction of a completely automated, computer controlled welding fume generation and inhalation exposure system for laboratory animals. The system is comprised of a programmable six-axis robotic welding arm and a water-cooled arc welding torch. A flexible trunk has been attached to the robotic arm of the welder and is used to collect and transport fume from the vicinity of the arc to the animal exposure chamber. Preliminary fume characterization studies have indicated that particle morphology, size, and chemical composition were comparable to welding fume generated in the workplace. Animal inhalation studies are currently underway. With the development of this novel system, an animal model has been established using controlled welding exposures to investigate the possible mechanisms by which welding fume may affect the central nervous system. PMID:16546258

  20. Pulmonary toxicity and extrapulmonary tissue distribution of metals after repeated exposure to different welding fumes.

    PubMed

    Antonini, James M; Roberts, Jenny R; Chapman, Rebecca S; Soukup, Joleen M; Ghio, Andrew J; Sriram, Krishnan

    2010-08-01

    Welders are exposed to fumes with different metal profiles. The goals of this study were to compare lung responses in rats after treatment with chemically different welding fumes and to examine the extrapulmonary fate of metals after deposition in the lungs. Rats were treated by intratracheal instillation (0.5 mg/rat, once a week for 7 weeks) with gas metal arc-mild steel (GMAW-MS) or manual metal arc-hardsurfacing (MMAW-HS) welding fumes. Controls were treated with saline. At 1, 4, 35, and 105 days after the last treatment, lung injury and inflammation were measured, and elemental analysis of different organs was determined to assess metal clearance. The MMAW-HS fume was highly water-soluble and chemically more complex with higher levels of soluble Mn and Cr compared to the GMAW-MS fume. Treatments with the GMAW-MS fume had no effect on toxicity when compared with controls. The MMAW-HS fume induced significant lung damage early after treatment that remained elevated until 35 days. Metals associated with each fume sample was cleared at different rates from the lungs. Mn was cleared from the lungs at a faster rate and to a greater extent compared to the other metals over the 105-day recovery period. Mn and Cr in the MMAW-HS fume translocated from the respiratory tract and deposited in other organs. Importantly, increased deposition of Mn, but not other metals, was observed in discrete brain regions, including dopamine-rich areas (e.g., striatum and midbrain). PMID:20560776

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    Sriram, Krishnan; Lin, Gary X; Jefferson, Amy M; Stone, Samuel; Afshari, Aliakbar; Keane, Michael J; McKinney, Walter; Jackson, Mark; Chen, Bean T; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared L; Roberts, Jenny R; Frazer, David G; Antonini, James M

    2015-02-01

    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/m(3); 3h/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. PMID:25549921

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

    PubMed Central

    Sriram, Krishnan; Lin, Gary X.; Jefferson, Amy M.; Stone, Samuel; Afshari, Aliakbar; Keane, Michael J.; McKinney, Walter; Jackson, Mark; Chen, Bean T.; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared L.; Roberts, Jenny R.; Frazer, David G.; Antonini, James M.

    2015-01-01

    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 ne 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. PMID:25549921

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

    PubMed Central

    2010-01-01

    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 lung injury. Since type of

  5. Reactive airways dysfunction syndrome following metal fume fever.

    PubMed

    Dube, Daniel; Puruckherr, Michael; Byrd, Ryland P; Roy, Thomas M

    2002-06-01

    Metal fume fever (MFF) is an acute response to the inhalation of heavy metals used in industry. The patient typically experiences symptoms of cough, fever, chills, malaise, and myalgia that are self-limited and of short duration. Wheezing may occur and pulmonary function may be acutely impaired with a decrease in lung volumes and diffusing capacity of carbon monoxide. Nevertheless, respiratory function quickly returns to normal, and persistent pulmonary insufficiency is unusual. Irritant-induced asthma is a non-immunogenic form of airway injury that may be associated with industrial inhalation exposure. In this situation, the direct toxic effect on the airways causes persistent airway inflammation and bronchial hyperreactivity. The two conditions are considered distinct entities, but we report a previously healthy worker who had classic MFF and was left with irritant-induced asthma or reactive airways dysfunction syndrome (RADS). PMID:12056129

  6. Microstructural characterization of a fumed titanium dioxide photocatalyst

    SciTech Connect

    Datye, A.K.; Huang, Min; Riegel, G.; Bolton, J.R.

    1995-02-15

    The authors present observations of a fumed titania photocatalyst using high resolution TEM and X-ray diffraction. The catalyst was observed as-received and after being used for photocatalytic destruction of salicylic acid. The characterization results suggest that the photocatalyst consists of individual single crystal particles of the rutile and anatase phases of titania; no amorphous titania particles could be identified conclusively. The authors also did not detect any particles of anatase that were covered by a layer of rutile, as proposed previously by Bickley et al. No changes were seen in the titania after it was used for photocatalysis of salicylic acid at pH 6 for short times (less than 1 hr).

  7. 30 CFR 72.701 - Respiratory equipment; gas, dusts, fumes, or mists.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... equipment; gas, dusts, fumes, or mists. Respiratory equipment approved by NIOSH under 42 CFR part 84 shall... mists. When the exposure is for prolonged periods, other measures to protect such persons or to...

  8. [Case of polymer fume fever with interstitial pneumonia caused by inhalation of polytetrafluoroethylene (Teflon)].

    PubMed

    Son, Masami; Maruyama, Eiichi; Shindo, Yuichiro; Suganuma, Nobukazu; Sato, Shinji; Ogawa, Masahiro

    2006-07-01

    A 30-year old man was admitted to our hospital with cough, slight fever, and dyspnea that he had developed several hours after inhaling the fumes produced from a Teflon-coated pan, after evaporation of the water in the pan. Chest radiography revealed diffuse infiltrations, and a computed tomography (CT) scan revealed patchy interstitial shadows in both lungs. In pulmonary function tests, the diffusing capacity of the lungs showed a moderate decrease. Leukocytosis and slight hypoxemia were observed. The patient recovered clinically in a few days without any specific treatment. We speculated that the pulmonary problems in this patient may have been induced by the products of thermal degradation of Teflon that were present in the fumes. When Teflon is heated, the fumes generated cause an influenza like syndrome (polymer fume fever) or cause severe toxic effects such as pulmonary edema, pneumonitis, and death in the exposed individual. PMID:16922460

  9. 5. West SideElevated Tank Structure with fume exhaust system and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. West Side-Elevated Tank Structure with fume exhaust system and support structure in foreground. - Mare Island Naval Shipyard, Acid Mixing Facility, California Avenue & E Street, Vallejo, Solano County, CA

  10. The mechanism of cesium immobilization in densified silica-fume blended cement pastes

    SciTech Connect

    Bar-Nes, G. Katz, A.; Peled, Y.; Zeiri, Y.

    2008-05-15

    The role of silica-fume agglomerates, found in densified silica-fume (DSF) pastes, in the immobilization mechanism of Cs ions was studied. Samples of cementitious pastes containing two different forms of silica fume - DSF and raw silica fume (RSF) - were prepared. Leaching experiments showed that both additives reduced the leachability of the metal ion, but the effect of the DSF paste was much stronger. Scanning Electron Microscopy, together with Differential Thermal Analysis, proved that no agglomerated particles were present in the RSF pastes and that the extent of pozzolanic reactivity was higher. We therefore believe that unreacted silica within the DSF agglomerates adsorbs Cs ions and consequently increases their immobilization. Furthermore, this work suggests that during the pozzolanic reaction, a hydrated rim develops around the agglomerate that acts as an additional diffusion barrier for the Cs ions, resulting in an increased efficiency of Cs immobilization.

  11. Workplace field testing of the pressure drop of particulate respirators using welding fumes.

    PubMed

    Cho, Hyun-Woo; Yoon, Chung-Sik

    2012-10-01

    In a previous study, we concluded that respirator testing with a sodium chloride aerosol gave a conservative estimate of filter penetration for welding fume aerosols. A rapid increase in the pressure drop (PD) of some respirators was observed as fumes accumulated on the filters. The present study evaluated particulate respirator PD based on workplace field tests. A field PD tester was designed and validated using the TSI 8130 Automatic Filter Tester, designed in compliance with National Institute for Occupational and Safety and Health regulation 42 CFR part 84. Three models (two replaceable dual-type filters and one replaceable single-type filter) were evaluated against CO(2) gas arc welding on mild steel in confined booths in the workplace. Field tests were performed under four airborne concentrations (27.5, 15.4, 7.9, and 2.1 mg m(-3)). The mass concentration was measured by the gravimetric method, and number concentration was monitored using P-Trak (Model 8525, TSI, USA). Additionally, photos and scanning electron microscopy-energy dispersive X-ray spectroscopy were used to visualize and analyze the composition of welding fumes trapped in the filters. The field PD tester showed no significant difference compared with the TSI tester. There was no significant difference in the initial PD between laboratory and field results. The PD increased as a function of fume load on the respirator filters for all tested models. The increasing PD trend differed by models, and PD increased rapidly at high concentrations because greater amount of fumes accumulated on the filters in a given time. The increase in PD as a function of fume load on the filters showed a similar pattern as fume load varied for a particular model, but different patterns were observed for different models. Images and elemental analyses of fumes trapped on the respirator filters showed that most welding fumes were trapped within the first layer, outer web cover, and second layer, in order, while no fumes

  12. A comparison between atmospheric/humidity and vacuum cyanoacrylate fuming of latent fingermarks.

    PubMed

    Farrugia, Kevin J; Fraser, Joanna; Friel, Lauren; Adams, Duncan; Attard-Montalto, Nicola; Deacon, Paul

    2015-12-01

    A number of pseudo-operational trials were set up to compare the atmospheric/humidity and vacuum cyanoacrylate fuming processes on plastic carrier bags. The fuming processes were compared using two-step cyanoacrylate fuming with basic yellow 40 (BY40) staining and a one-step fluorescent cyanoacrylate fuming, Lumicyano 4%. Preliminary work using planted fingermarks and split depletions were performed to identify the optimum vacuum fuming conditions. The first pseudo-operational trial compared the different fuming conditions (atmospheric/humidity vs. vacuum) for the two-step process where an additional 50% more marks were detected with the atmospheric/humidity process. None of the marks by the vacuum process could be observed visually; however, a significant number of marks were detected by fluorescence after BY40 staining. The second trial repeated the same work in trial 1 using the one-step cyanoacrylate process, Lumicyano at a concentration of 4%. Trial 2 provided comparable results to trial 1 and all the items were then re-treated with Lumicyano 4% at atmospheric/humidity conditions before dyeing with BY40 to provide the sequences of process A (Lumicyano 4% atmospheric-Lumicyano 4% atmospheric-BY40) and process B (Lumicyano 4% vacuum-Lumicyano 4% atmospheric-BY40). The number of marks (visual and fluorescent) was counted after each treatment with a substantial increase in the number of detected marks in the second and third treatments of the process. The increased detection rate after the double Lumicyano process was unexpected and may have important implications. Trial 3 was performed to investigate whether the amount of cyanoacrylate and/or fuming time had an impact on the results observed in trial 2 whereas trial 4 assessed if the double process using conventional cyanoacrylate, rather than Lumicyano 4%, provided an increased detection rate. Trials 3 and 4 confirmed that doubling the amount of Lumicyano 4% cyanoacrylate and fuming time produced a lower

  13. Strength and pore structure of ternary blended cement mortars containing blast furnace slag and silica fume

    SciTech Connect

    Bagel, L.

    1998-07-01

    Blended cement mortars with fixed workability and incorporating blast furnace slag and silica fume, were tested for compressive strength and mercury intrusion, with a view to comparing their performance with that of plain Portland cement mortar and/or slag-cement mortar. The obtained results showed that with high portions of slag and silica fume in the binding system, the mortars reached relatively satisfactory level of compressive strength and contributed to the significantly denser pore structure.

  14. 42 CFR 84.1158 - Dust, fume, and mist tests; respirators with filters; minimum requirements; general.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Respirator types Pressure tightness test 1 Isoamyl acetate test 84.1141 84.1142 Dusts: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Fumes: Air Contamination Level not less than 0.05 mg/M3 X X Mists: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Dusts, Fumes, and Mists:...

  15. 42 CFR 84.1158 - Dust, fume, and mist tests; respirators with filters; minimum requirements; general.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Respirator types Pressure tightness test 1 Isoamyl acetate test 84.1141 84.1142 Dusts: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Fumes: Air Contamination Level not less than 0.05 mg/M3 X X Mists: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Dusts, Fumes, and Mists:...

  16. 42 CFR 84.1158 - Dust, fume, and mist tests; respirators with filters; minimum requirements; general.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Respirator types Pressure tightness test 1 Isoamyl acetate test 84.1141 84.1142 Dusts: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Fumes: Air Contamination Level not less than 0.05 mg/M3 X X Mists: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Dusts, Fumes, and Mists:...

  17. 42 CFR 84.1158 - Dust, fume, and mist tests; respirators with filters; minimum requirements; general.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Respirator types Pressure tightness test 1 Isoamyl acetate test 84.1141 84.1142 Dusts: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Fumes: Air Contamination Level not less than 0.05 mg/M3 X X Mists: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Dusts, Fumes, and Mists:...

  18. 42 CFR 84.1158 - Dust, fume, and mist tests; respirators with filters; minimum requirements; general.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Respirator types Pressure tightness test 1 Isoamyl acetate test 84.1141 84.1142 Dusts: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Fumes: Air Contamination Level not less than 0.05 mg/M3 X X Mists: Air Contamination Level not less than 0.05 mg/M3 or 2 mppcf X Dusts, Fumes, and Mists:...

  19. Numerical investigation of turbulent diffusion in push-pull and exhaust fume cupboards.

    PubMed

    Chern, Ming-Jyh; Cheng, Wei-Ying

    2007-08-01

    The aim of this study is to investigate airflow motions and associated pollutant distributions in fume hoods. Currently, most exhaust fume hoods are designed to use an airflow induced by a fan at the top to remove pollutants. Ambient fluids are drawn, flowing toward the opening and subsequently turning to the outlet at the roof. Pollutants are supposedly captured by the airflow and brought out from the cupboard. The present numerical study based on the finite-volume method and the standard k-epsilon turbulence model simulates flow patterns and pollutant distributions in an exhaust fume hood with and without a manikin present. Subsequently, a push-pull air curtain technique is applied to a fume cupboard. To investigate the capturing performance of a push-pull fume cupboard, numerical approaches are used to simulate flow and concentration variations. Numerical results reveal that four characteristic flow modes exist for a variety of speed ratios of push-pull flows and openings. A concave curtain mode which has a fast pull flow and a weak push flow is suggested for the operation of a push-pull fume cupboard. According to ANSI-ASHRAE Standard 110-1995, the local concentration at the specified point is <0.1 parts per million (p.p.m.). Meanwhile, we also examine concentration variations at 12 selected points in front of the sash, and all where the concentration is <0.1 p.p.m. A manikin is put in front of the sash to observe its effect. As a result, the flow and the concentration contours in a push-pull fume cupboard are not affected by a manikin. In terms of those predicted results, it turns out that a push-pull fume cupboard successfully captures pollutants and prevents an operator from breathing pollutants. PMID:17638713

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

    PubMed

    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

  1. Alternatives for Benzene in the Extraction of Bitumen Fume from Exposure Sample Media.

    PubMed

    Sutter, Benjamin; Ravera, Christel; Hussard, Caroline; Langlois, Eddy

    2016-01-01

    Benzene is frequently used to extract collected bitumen fumes from personal sampler substrates. However, this solvent is particularly dangerous because of its carcinogenicity (group 1 of the International Agency for Research on Cancer classification). Therefore, to prevent the exposure of laboratory technicians to benzene during the fume extraction step from samplers, a compromise had to be found to identify a less toxic solvent with the same extraction capacity. To compare the extraction capacities of selected solvents, bitumen fumes were generated in the laboratory from three different batches of road surfacing bitumen collected on dedicated bitumen fume samplers. The samplers were then extracted by benzene and the solvents tested. Of 11 selected solvents less toxic than benzene and used in studies on bitumen and bitumen fume analyses, n-hexane and n-heptane were identified as alternatives to benzene. In particular, the results demonstrated that n-heptane was the best candidate solvent for benzene replacement, due to its extraction efficiency comparable to benzene for the three bitumen fumes tested and its low toxicity, which is highly compatible with benzene replacement. PMID:26400870

  2. Alterations in welding process voltage affect the generation of ultrafine particles, fume composition, and pulmonary toxicity.

    PubMed

    Antonini, James M; Keane, Michael; Chen, Bean T; Stone, Samuel; Roberts, Jenny R; Schwegler-Berry, Diane; Andrews, Ronnee N; Frazer, David G; Sriram, Krishnan

    2011-12-01

    The goal was to determine if increasing welding voltage changes the physico-chemical properties of the fume and influences lung responses. Rats inhaled 40 mg/m³ (3 h/day × 3 days) of stainless steel (SS) welding fume generated at a standard voltage setting of 25 V (regular SS) or at a higher voltage (high voltage SS) of 30 V. Particle morphology, size and composition were characterized. Bronchoalveolar lavage was performed at different times after exposures to assess lung injury. Fumes collected from either of the welding conditions appeared as chain-like agglomerates of nanometer-sized primary particles. High voltage SS welding produced a greater number of ultrafine-sized particles. Fume generated by high voltage SS welding was higher in manganese. Pulmonary toxicity was more substantial and persisted longer after exposure to the regular SS fume. In summary, a modest raise in welding voltage affected fume size and elemental composition and altered the temporal lung toxicity profile. PMID:21281223

  3. Mutagenicity and aromatic amine content of fumes from heated cooking oils produced in Taiwan.

    PubMed

    Chiang, T A; Pei-Fen, W; Ying, L S; Wang, L F; Ko, Y C

    1999-01-01

    According to toxicological studies, there are several unidentified mutagens derived from cooking oil fumes appearing in kitchens of Chinese homes where women daily prepare food. Data are limited to an analysis of aromatic amines from cooking oil fumes, which are known to be carcinogenic for bladder cancer. Fume samples from three different commercial cooking oils frequently used in Taiwan were collected and analysed for mutagenicity in the Salmonella/microsome assay. Aromatic amines were extracted from the samples and identified by HPLC and confirmed by gas chromatography/mass spectrometry (GC/MS). Extracts from three cooking oil fumes were found to be mutagenic in the presence of S-9 mix. All samples contained 2-naphthylamine (2-NA) and 4-aminobiphenyl (4-ABP). Concentrations of 2-NA and 4-ABP were 31.5 and 35.7 microg/m3 in fumes from sunflower oil, 31.9 and 26.4 mg/m3 in vegetable oil, and 48.3 and 23.3 microg/m3 in refined-lard oil, respectively. Mutagenicities of the three cooking oil condensates were significantly reduced (P<0.05) by adding the antioxidant catechin (CAT) into the oils before heating. Significant difference existed between the amounts of aromatic amines with and without adding CAT (P<0.05). These results indicate that exposure to cooking oil fumes in Taiwan might be an important but controllable risk factor in the aetiology of bladder cancer. PMID:10227736

  4. Manganese speciation of laboratory-generated welding fumes

    PubMed Central

    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 steel (SS) and mild carbon steel (MCS) and also with flux cored arc welding (FCAW) and shielded metal arc welding (SMAW) using MCS. Generated WF samples were collected onto polycarbonate filters before homogenization, weighing and storage in scintillation vials. The extraction procedure consisted of four sequential steps to measure various Mn fractions based upon selective solubility: (1) soluble Mn dissolved in 0.01 M ammonium acetate; (2) Mn (0,II) dissolved in 25 % (v/v) acetic acid; (3) Mn (III,IV) dissolved in 0.5% (w/v) hydroxylamine hydrochloride in 25% (v/v) acetic acid; and (4) insoluble Mn extracted with concentrated hydrochloric and nitric acids. After sample treatment, the four fractions were analyzed for Mn by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). WF from GMAW and FCAW showed similar distributions of Mn species, with the largest concentrations of Mn detected in the Mn (0,II) and insoluble Mn fractions. On the other hand, the majority of the Mn content of SMAW fume was detected as Mn (III,IV). Although the concentration of Mn measured from summation of the four sequential steps was statistically significantly different from that measured from the hot block dissolution method for total Mn, the difference is small enough to be of no practical importance for industrial hygiene air samples, and either method may be used for Mn measurement. The sequential extraction method provides valuable information about the oxidation state of Mn in samples

  5. Work Environments and Exposure to Hazardous Substances in Korean Tire Manufacturing

    PubMed Central

    Lee, Byung-kyu; Jeong, Sijeong; Yi, Gwang Yong; Shin, Jungah

    2012-01-01

    Objectives The purpose of this study is to evaluate the tire manufacturing work environments extensively and to identify workers' exposure to hazardous substances in various work processes. Methods Personal air sampling was conducted to measure polycyclic aromatic hydrocarbons, carbon disulfide, 1,3-butadiene, styrene, methyl isobutyl ketone, methylcyclohexane, formaldehyde, sulfur dioxide, and rubber fume in tire manufacturing plants using the National Institute for Occupational Safety Health Manual of Analytical Methods. Noise, carbon monoxide, and heat stress exposure were evaluated using direct reading instruments. Past concentrations of rubber fume were assessed using regression analysis of total particulate data from 2003 to 2007, after identifying the correlation between the concentration of total particulate and rubber fume. Results Workers were exposed to rubber fume that exceeded 0.6 mg/m3, the maximum exposure limit of the UK, in curing and production management processes. Forty-seven percent of workers were exposed to noise levels exceeding 85 dBA. Workers in the production management process were exposed to 28.1℃ (wet bulb globe temperature value, WBGT value) even when the outdoor atmosphere was 2.7℃ (WBGT value). Exposures to other substances were below the limit of detection or under a tenth of the threshold limit values given by the American Conference of Governmental Industrial Hygienists. Conclusion To better classify exposure groups and to improve work environments, examining closely at rubber fume components and temperature as risk indicators in tire manufacturing is recommended. PMID:22993718

  6. Effects of paving asphalt fume exposure on genotoxic and mutagenic activities in the rat lung.

    PubMed

    Zhao, H W; Yin, X J; Frazer, D; Barger, M W; Siegel, P D; Millecchia, L; Zhong, B Z; Tomblyn, S; Stone, S; Ma, J K H; Castranova, V; Ma, J Y C

    2004-02-14

    Asphalt fumes are complex mixtures of aerosols and vapors containing various organic compounds, including polycyclic aromatic hydrocarbons (PAHs). Previously, we have demonstrated that inhalation exposure of rats to asphalt fumes resulted in dose-dependent induction of CYP1A1 with concomitant down-regulation of CYP2B1 and increased phase II enzyme quinone reductase activity in the rat lung. In the present study, the potential genotoxic effects of asphalt fume exposure due to altered lung microsomal enzymes were studied. Rats were exposed to air or asphalt fume generated under road paving conditions at various concentrations and sacrificed the next day. Alveolar macrophages (AM) were obtained by bronchoalveolar lavage and examined for DNA damage using the comet assay. To evaluate the systemic genotoxic effect of asphalt fume, micronuclei formation in bone marrow polychromatic erythrocytes (PCEs) was monitored. Lung S9 from various exposure groups was isolated from tissue homogenates and characterized for metabolic activity in activating 2-aminoanthracene (2-AA) and benzo[a]pyrene (BaP) mutagenicity using the Ames test with Salmonella typhimurium YG1024 and YG1029. This study showed that the paving asphalt fumes significantly induced DNA damage in AM, as revealed by DNA migration in the comet assay, in a dose-dependent manner, whereas the micronuclei formation in bone marrow PCEs was not detected even at a very high exposure level (1733 mg h/m3). The conversion of 2-AA to mutagens in the Ames test required lung S9-mediated metabolic activation in a dose-dependent manner. In comparison to the controls, lung S9 from rats exposed to asphalt fume at a total exposure level of 479+/-33 mg h/m3 did not significantly enhance 2-AA mutagenicity with either S. typhimurium YG1024 or YG1029. At a higher total asphalt fume exposure level (1150+/-63 mg h/m3), S9 significantly increased the mutagenicity of 2-AA as compared to the control. However, S9 from asphalt fume-exposed rats

  7. Reproductive Hazards

    MedlinePlus

    ... such as lead and mercury Chemicals such as pesticides Cigarettes Some viruses Alcohol For men, a reproductive hazard can affect the sperm. For a woman, a reproductive hazard can cause different effects during pregnancy, depending on when she is exposed. ...

  8. Exposure to fumes in typical New Zealand welding operations.

    PubMed

    Dryson, E W; Rogers, D A

    1991-08-28

    Sixteen welders, welding under typical New Zealand conditions, had ambient air within their welding helmets sampled and analysed for ozone, nitrogen oxides, fluoride, carbon monoxide, aluminium, chromium, iron, nickel, zinc and total dust. Postshift urinary metals were also analysed, and a respiratory questionnaire completed for each welder. Levels above the New Zealand Workplace Exposure Standard (WES) were found for nitrogen dioxide in four welders (two TIG, one MMA and one plasma cutter), and for total chromium in one plasma cutter, who also had a nickel level of 24% of the WES. Dust levels were highest in the plasma cutters, with one reaching 8.67 mg/m3 (WES = 5 mg/m3). Urinary levels however did not indicate excessive short or long term uptake. Where efficient fume extraction was in use, levels of air contaminants were lower than with natural ventilation. Respiratory symptoms were reported by 67% of welders, 38% meeting criteria for chronic bronchitis (relative risk = 2.0). Smoking welders reported more symptoms than nonsmoking welders. PMID:1891137

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

    PubMed

    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

  10. Accidental exposure to isocyanate fumes in a group of firemen.

    PubMed Central

    Axford, A T; McKerrow, C B; Jones, A P; Le Quesne, P M

    1976-01-01

    A total of 35 firemen involved in fighting a fire in a factory in which polyurethane foam was made were exposed to fumes of toluene di-isocyanate from two large storage tanks which were damaged during the fire, resulting in massive spillage. Most of the men experienced symptoms during the fire or during the three weeks after it. The symptoms were mainly gastrointestinal, respiratory, or neurological. Altogether 15 men described gastrointestinal symptoms which subsided within two days of onset. Respiratory symptoms were described by 31 men and were most pronounced during the three days after the fire, thereafter tending to improve. The neurological findings are described separately. When the men were reviewed at six months there was a suggestion that some of them might have sustained long-term damage to the respiratory tract, and almost four years later 20 men had persistent respiratory symptoms. Serial measurements of ventilatory capacity revealed a marked decline in the first six months although this was not sustained. PMID:179561

  11. Respiratory response of guinea pigs to zinc oxide fume

    SciTech Connect

    Amdur, M.O.; McCarthy, J.F.; Gill, M.W.

    1983-02-01

    Zinc has been found enriched in the fine particle fraction of atmospheric aerosols and in the surface layer of fly ash. Experimental combustion studies of coal have demonstrated that zinc is vaporized and recondensed into the submicrometer fraction of the combustion aerosols. This size fraction may contain as much as 1.5% zinc when a coal of high zinc content (Illinois No. 6) is used. Zinc sulfate and zinc ammonium sulfate are among the sulfates with demonstrable irritant potency. Zinc oxide was thus chosen as the initial aerosol for studies of biological and chemical interaction of high temperature generated submicrometer metal oxides with sulfur dioxide. This paper reports the respiratory response of guinea pigs to short term exposure to freshly formed zinc oxide fume. These studies of zinc oxide alone have relevance to industrial exposure. The recommended TLV for zinc oxide is 5 mg/m/sup 3/ and the recommended STEL is 10 mg/m/sup 3/. Concentrations used in our studies were below these recommended levels.

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

    SciTech Connect

    Pathanjali, C.; Rahman, M.M.

    1996-12-31

    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.

  13. International studies to compare methods for personal sampling of bitumen fumes.

    PubMed

    Ekström, L G; Kriech, A; Bowen, C; Johnson, S; Breuer, D

    2001-10-01

    A newly recommended Institute of Occupational Medicine (IOM) sampler, optimized for the inhalable fraction, was compared with 'total particulate' samplers currently used by five laboratories in different countries for the analysis of bitumen fumes. Using a laboratory fume generator, all samplers were uniformly exposed to bitumen fumes from typical USA bitumen (commercial Pen 65). The results show that, for laboratory-generated bitumen fumes, benzene-extractable inhalable particulate data for the IOM sampler are consistent with benzene soluble matter data from the other samplers. Direct comparison of the IOM sampler with the 37 mm closed-face cassette (USA sampler) using an identical protocol in a single laboratory gave a ratio of 1.05:1 (USA:IOM). Similarly, for total particulate matter, the standard previously recommended by the American Conference of Governmental Industrial Hygienists (ACGIH), an average value of approximately 1 between the IOM and the five samplers was obtained. For unadulterated bitumen fumes, the geometry of the cassettes does not appear to affect entry of the particles into the sampler. Field studies may show differences in results as other factors, e.g. wind and its effect on sampling efficiency, and also particulates originating from sources other than bitumen, such as dust, are involved. These will require thorough investigation prior to the assessment of the impact of the new sampler and prior to any reconsideration of occupational exposure limits taking into account practical feasibility. Other tests were conducted on the bitumen fume samples including total organic matter, simulated distillation and polycyclic aromatic compound analysis. These additional tests were performed on the fume collected on the filter plus the volatile portion that passed through the filter and was captured on various adsorbent materials. Protocols for sample collection and analysis varied in different countries with results reflective of these differences

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

    NASA Astrophysics Data System (ADS)

    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.

  15. Home cage locomotor changes in non-human primates after prolonged welding-fume exposure.

    PubMed

    Kim, Choong Yong; Sung, Jae Hyuck; Chung, Yong Hyun; Park, Jung Duck; Han, Jeong Hee; Lee, Jong Seong; Heo, Jeong Doo; Yu, Il Je

    2013-12-01

    To define the relationship between the brain concentration of manganese and neurological signs, such as locomotion, after prolonged welding-fume exposure, cynomolgus monkeys were acclimated for 1 month and then divided into three concentration groups: unexposed, low concentration (31 mg/m(3) total suspended particulate (TSP), 0.9 mg/m(3) of Mn), and high concentration (62 mg/m(3) TSP, 1.95 mg/m(3) of Mn) of TSP. The monkeys were exposed to manual metal-arc stainless steel (MMA-SS) welding fumes for 2 h per day over 8 months in an inhalation chamber system equipped with an automatic fume generator. The home cage locomotor activity and patterns were determined using a camera system over 2-4 consecutive days. After 25 and 32 weeks of exposure, the home cage locomotor activity of the high-concentration primates was found to be 5-6 times higher than that of the unexposed primates, and this increased locomotor activity was maintained for 7 weeks after ceasing the welding-fume exposure, eventually subsiding to three times higher after 13 weeks of recovery. Therefore, the present results, along with our previous observations of a high magnetic resonance imaging (MRI) T1 signal in the globus pallidus and increased blood Mn concentration, indicate that prolonged welding-fume exposure can cause neurobehavioral changes in cynomolgus monkeys. PMID:24304306

  16. Effects of Exposure to Welding Fume on Lung Function: Results from the German WELDOX Study.

    PubMed

    Lehnert, M; Hoffmeyer, F; Gawrych, K; Lotz, A; Heinze, E; Berresheim, H; Merget, R; Harth, V; Van Gelder, R; Hahn, J-U; Hartwig, A; Weiß, T; Pesch, B; Brüning, T

    2015-01-01

    The association between exposure to welding fume and chronic obstructive pulmonary disease (COPD) has been insufficiently clarified. In this study we assessed the influence of exposure to welding fume on lung function parameters. We investigated forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC, and expiratory flow rates in 219 welders. We measured current exposure to respirable particles and estimated a worker's lifetime exposure considering welding techniques, working conditions and protective measures at current and former workplaces. Multiple regression models were applied to estimate the influence of exposure to welding fume, age, and smoking on lung function. We additionally investigated the duration of working as a welder and the predominant welding technique. The findings were that age- and smoking-adjusted lung function parameters showed no decline with increasing duration, current exposure level, and lifetime exposure to welding fume. However, 15% of the welders had FEV1/FVC below the lower limit of normal, but we could not substantiate the presence of an association with the measures of exposure. Adverse effects of cigarette smoking were confirmed. In conclusion, the study did not support the notion of a possible detrimental effect of exposure to welding fume on lung function in welders. PMID:25315619

  17. Increase of the reactivity of densified silica fume by sonication treatment.

    PubMed

    Rodríguez, Erich D; Soriano, Lourdes; Payá, Jordi; Borrachero, María Victoria; Monzó, José M

    2012-09-01

    Five silica fumes from different manufacturers were subjected to ultrasonic treatment in order to decrease particle agglomeration and improve particle dispersion. The effectiveness of the sonication was observed as a reduction in particle size distribution of sonicated silica fume (SSF) compared to non-sonicated silica fume. SSF was added to Portland cement, and then the hydrated paste was analysed by thermogravimetric analyses (TGA/DTG) and scanning electron microscopy (SEM/EDX). The results were compared with those of control pastes made with untreated densified silica fume (DSF), as well as a reference cement paste of ordinary Portland cement (OPC). A maximum grade of de-agglomeration by the sonication was obtained, with a high volume of particles of diameter less than 1 μm. Images obtained by transmission electron microscopy (TEM) of the SSF showed sintered particles that could not be fragmented by the treatment. Micro-structural characterisation results showed an increase in the reactivity of the silica fume after the treatment. PMID:22356800

  18. Study of flow patterns in fume hood enclosures

    SciTech Connect

    Pathanjali, C.; Rahman, M.M.

    1996-12-31

    A three-dimensional model for flow inside a fume hood enclosure was developed and numerical computations were carried out to explore the flow pattern and possible path of contaminant transport under different operating conditions of the hood. Equations for the conservation of mass and momentum were solved for different flow rate and opening conditions in the hood. The face velocity was maintained constant at its rated value of 0.4 m/s. The flow was assumed to enter through the front window opening (positive x-direction) and leave the cupboard through an opening on the top of the hood (positive z-direction). The flow was assumed to be fully turbulent. The {kappa}-{var_epsilon} model was used for the prediction of turbulence. The flow pattern for different sash openings were studied. The flow patterns around an object located at the bottom of the hood was studied for different locations of the object. In addition, the effect of a person standing in front of the hood on the flow pattern was investigated. 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 trailing 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. The computed flow patterns will be very useful to design experiments with optimum sash opening providing adequate disposal of contaminants with minimum use of conditioned air from inside the room.

  19. Natural Hazards

    NASA Astrophysics Data System (ADS)

    Bryant, Edward

    2005-02-01

    This updated new edition presents a comprehensive, inter-disciplinary analysis of the complete range of natural hazards. Edward Bryant describes and explains how hazards occur, examines prediction methods, considers recent and historical hazard events and explores the social impact of such disasters. Supported by over 180 maps, diagrams and photographs, this standard text is an invaluable guide for students and professionals in the field. First Edition Hb (1991): 0-521-37295-X First Edition Pb (1991): 0-521-37889-3

  20. Quantitative {sup 29}Si MAS NMR spectroscopy of cement and silica fume containing paramagnetic impurities

    SciTech Connect

    Hilbig, H. . E-mail: hilbig@cbm.bv.tum.de; Koehler, F.H.; Schiessl, P.

    2006-02-15

    The low natural abundance and the long spin lattice relaxation time of {sup 29}Si lead to long measurement times and/or low signal-to-noise ratios using {sup 29}Si magic angle spinning NMR spectroscopy. By contrast, samples containing paramagnetic iron ions have much shorter relaxation times, making measurements up to seven times more efficient, but at the same time making quantitative analysis unreliable. To solve the problem, the spin-lattice relaxation times of ordinary Portland cement (opc) and silica fume with and without iron content has been determined with inversion recovery experiments. The effect of varying the spectrum repetition time on the quantitative analysis is demonstrated for mixtures of opc with silica fume. For opc and silica fume with iron impurities repetition times as short as 5 s has permitted accurate quantitative analysis of the silicates present in these materials.

  1. 42 CFR 84.1152 - Silica dust loading test; respirators designed as protection against dusts, fumes, and mists...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 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...

  2. 42 CFR 84.1152 - Silica dust loading test; respirators designed as protection against dusts, fumes, and mists...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 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...

  3. 42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Dust, fume, and mist air-purifying filter tests; performance requirements; general. 84.1143 Section 84.1143 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... Efficiency Respirators and Combination Gas Masks § 84.1143 Dust, fume, and mist air-purifying filter...

  4. 42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Dust, fume, and mist air-purifying filter tests; performance requirements; general. 84.1143 Section 84.1143 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... Efficiency Respirators and Combination Gas Masks § 84.1143 Dust, fume, and mist air-purifying filter...

  5. 42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Dust, fume, and mist air-purifying filter tests; performance requirements; general. 84.1143 Section 84.1143 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... Efficiency Respirators and Combination Gas Masks § 84.1143 Dust, fume, and mist air-purifying filter...

  6. 42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Dust, fume, and mist air-purifying filter tests; performance requirements; general. 84.1143 Section 84.1143 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... Efficiency Respirators and Combination Gas Masks § 84.1143 Dust, fume, and mist air-purifying filter...

  7. 42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Dust, fume, and mist air-purifying filter tests; performance requirements; general. 84.1143 Section 84.1143 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... Efficiency Respirators and Combination Gas Masks § 84.1143 Dust, fume, and mist air-purifying filter...

  8. Kinetics of the zinc slag-Fuming process: Part i. industrial measurements

    NASA Astrophysics Data System (ADS)

    Richards, G. G.; Brimacombe, J. K.; Toop, G. W.

    1985-09-01

    A study involving industrial measurements and mathematical modeling has been conducted to eluci-date kinetic phenomena in the zinc slag fuming process. In the first part of this three-part paper, the results of industrial measurements and observations are presented. In Part II a mathematical model of the process is developed, and finally in Part III the implications of a kinetic conception of the process for process improvement are explored. The industrial work consisted primarily of slag sampling through the fuming cycles of five different fuming operations. In addition, tuyere back-pressure mea-surements, tuyere photography using a tuyerescope, and sampling of the fume product were under-taken at one operation. Analysis of the slag samples has shown that, in general, the zinc elimination curve is linear with time and that a portion of the injected coal entrains in the slag. Analysis of tuyere back-pressure fluctuations and movie photographs of the tuyere tip indicate that the coal-air mixture enters the slag in the form of discrete bubbles. From these results it can be deduced that the fuming furnace consists of two reaction zones which are created by the division of coal between the slag and the tuyere gas stream. The coal entrained in the slag reduces ZnO and Fe3O4 in a “reduction zone” which is responsible for fuming. The coal remaining in the tuyere gas stream combusts in an “oxidation zone” although a fraction passes through the bath unconsumed and reports to the solid products. The oxidation zone supplies heat to the endothermic reduction reactions and heat losses.

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

    PubMed

    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. Energy efficient fume and odor control equipment for coil coating line

    SciTech Connect

    Coughran, G.

    1982-06-01

    Wolverine Aluminum Corporation, producer of exterior siding building material, recently installed a Variable Energy Recovery Control System at its Lincoln Park coil coating plant. Boilers had an incinerator which emitted odors and consumed large volumes of gas. The fume incinerators were eliminated by one Model G 56,000 SCFM RE-THE M thermal Oxidizer from Reeco of Morris Plains, NJ. Its chambers, preheaters, two main ducts, and other design features are described. Installation was simple, as was operation. Fumes and odor have been controlled; operating costs have been reduced.

  11. Hazardous materials

    MedlinePlus

    ... people how to work with hazardous materials and waste. There are many different kinds of hazardous materials, including: Chemicals, like some that are used for cleaning Drugs, like chemotherapy to treat cancer Radioactive material that is used for x-rays or ...

  12. Influence of welding fume on systemic iron status.

    PubMed

    Casjens, Swaantje; Henry, Jana; Rihs, Hans-Peter; Lehnert, Martin; Raulf-Heimsoth, Monika; Welge, Peter; Lotz, Anne; Gelder, Rainer Van; Hahn, Jens-Uwe; Stiegler, Hugo; Eisele, Lewin; Weiss, Tobias; Hartwig, Andrea; Brüning, Thomas; Pesch, Beate

    2014-11-01

    Iron is the major metal found in welding fumes, and although it is an essential trace element, its overload causes toxicity due to Fenton reactions. To avoid oxidative damage, excess iron is bound to ferritin, and as a result, serum ferritin (SF) is a recognized biomarker for iron stores, with high concentrations linked to inflammation and potentially also cancer. However, little is known about iron overload in welders. Within this study, we assessed the iron status and quantitative associations between airborne iron, body iron stores, and iron homeostasis in 192 welders not wearing dust masks. Welders were equipped with personal samplers in order to determine the levels of respirable iron in the breathing zone during a working shift. SF, prohepcidin and other markers of iron status were determined in blood samples collected after shift. The impact of iron exposure and other factors on SF and prohepcidin were estimated using multiple regression models. Our results indicate that respirable iron is a significant predictor of SF and prohepcidin. Concentrations of SF varied according to the welding technique and respiratory protection used, with a median of 103 μg l(-1) in tungsten inert gas welders, 125 μg l(-1) in those wearing air-purifying respirators, and 161 μg l(-1) in other welders. Compared to welders with low iron stores (SF < 25 μg l(-1)), those with excess body iron (SF ≥ 400 μg l(-1)) worked under a higher median concentration of airborne iron (60 μg m(-3) versus 148 μg m(-3)). Even though air concentrations of respirable iron and manganese were highly correlated, and low iron stores have been reported to increase manganese uptake in the gastrointestinal tract, no correlation was seen between SF and manganese in blood. In conclusion, monitoring SF may be a reasonable method for health surveillance of welders. Respiratory protection with air-purifying respirators can decrease iron exposure and avoid chronically higher SF in welders working with

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

    PubMed

    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

  14. Low Temperature Synthesis of Belite Cement Based on Silica Fume and Lime

    PubMed Central

    Tantawy, M. A.; Shatat, M. R.; El-Roudi, A. M.; Taher, M. A.; Abd-El-Hamed, M.

    2014-01-01

    This paper describes the low temperature synthesis of belite (β-C2S) from silica fume. Mixtures of lime, BaCl2, and silica fume with the ratio of (Ca + Ba)/Si = 2 were hydrothermally treated in stainless steel capsule at 110–150°C for 2–5 hours, calcined at 600–700°C for 3 hours, and analyzed by FTIR, XRD, TGA/DTA, and SEM techniques. Dicalcium silicate hydrate (hillebrandite) was prepared by hydrothermal treatment of lime/silica fume mixtures with (Ca + Ba)/Si = 2 at 110°C for 5 hours. Hillebrandite partially dehydrates in two steps at 422 and 508°C and transforms to γ-C2S at 734°C which in turn transforms to α′-C2S at 955°C which in turn transforms to β-C2S when cooled. In presence of Ba2+ ions, β-C2S could be stabilized with minor transformation to γ-C2S. Mixture of silica fume, lime, and BaCl2 with the ratio of (Ca + Ba)/Si = 2 was successfully utilized for synthesis of β-C2S by hydrothermal treatment at 110°C for 5 hours followed by calcination of the product at 700°C for 3 hours. PMID:27437495

  15. Blunted Behavioral and C Fos Responses to Acidic Fumes in the African Naked Mole-Rat

    PubMed Central

    LaVinka, Pamela Colleen; Park, Thomas J.

    2012-01-01

    Acidosis in the skin triggers activation of pain pathways and behaviors indicative of pain in vertebrates. The exception is the naked mole-rat, the only known vertebrate to show physiological and behavioral insensitivity to acid pain in the skin. The goal of the present study was to determine behavioral and physiological responses of this species to airborne acidic fumes, which would be expected to affect the trigeminal pain pathway in other species. Behaviorally, naked mole-rats did not avoid fumes from moderately high concentrations of acetic acid (10 and 20%), and c Fos labeling showed no increase in activity in the trigeminal nuclei and nucleus tractus solitarius. In contrast, these concentrations triggered behavioral aversion and increased Fos activity in other laboratory rodents. For a very high concentration of acetic acid (50%), naked mole-rats showed significant avoidance behavior and increased Fos labeling in the nucleus tractus solitarius caudal region, which receives vagal chemosensory information. However, there was no increase in trigeminal labeling, and in fact, activity significantly decreased. This pattern is opposite of that associated with another irritant, ammonia fumes, which elicited an increase in trigeminal but not nucleus tractus solitarius Fos labeling, and no behavioral avoidance. Behavioral avoidance of acidic fumes, but no increased labeling in the trigeminal pain nucleus is consistent with the notion of adaptations to blunt acid pain, which would be advantageous for naked mole-rats as they normally live under chronically high levels of acidosis-inducing CO2. PMID:23028761

  16. The Use of Feedback in Lab Energy Conservation: Fume Hoods at MIT

    ERIC Educational Resources Information Center

    Wesolowski, Daniel; Olivetti, Elsa; Graham, Amanda; Lanou, Steve; Cooper, Peter; Doughty, Jim; Wilk, Rich; Glicksman, Leon

    2010-01-01

    Purpose: The purpose of this paper is to report on the results of an Massachusetts Institute of Technology Chemistry Department campaign to reduce energy consumption in chemical fume hoods. Hood use feedback to lab users is a crucial component of this campaign. Design/methodology/approach: Sash position sensor data on variable air volume fume…

  17. Fume hood performance: Using a bypass in variable air volume systems

    SciTech Connect

    Joao, R.V.; Party, E.; Gershey, E.L.

    1998-10-01

    Variable air volume (VAV) exhaust systems provide sophisticated engineering controls for maintaining laboratory ventilation. Depending on how they are installed, they may be very responsive to changes in air flows and air pressures. Some of these changes are a consequence of natural phenomena and some are induced by the transit and actions of laboratory occupants. While the responsiveness of VAV controls can provide tight regulation, the dynamic nature of the VAV system may also introduce undesirable air flow fluctuations. Furthermore, since the volumes of air being exhausted vary, the amount of air available for fume hood capture and containment will also vary. These studies examine the responsiveness and consequences of ventilation system perturbations, as well as the effect of fume hood exhaust being reduced to very low air volumes. Face velocity and air volumes were measured at different sash heights and in response to rapid sash movements. In addition, capture of contaminants was evaluated at different sash heights by American National Standards Institute/American Society of Heating, Refrigerating, and Air-Conditioning Engineers 110-85 tests. The authors have found that at low sash heights the total volume of air may be reduced to a level that is insufficient to efficiently capture airborne contaminants. The addition of a fume hood bypass was necessary to ensure that the volume of air exhausted is sufficient to remove the contaminants present. Understanding the causes and characteristics of fume hood instabilities provides insight into how to prevent these perturbations.

  18. Hazardous materials

    MedlinePlus

    ... should be in a room with good airflow Work Safely If you find a spill, treat it like ... Hazard communication; Material Safety Data Sheet; MSDS References Occupational Safety and Health Administration. Healthcare. Available at: www.osha. ...

  19. Coastal Hazards.

    ERIC Educational Resources Information Center

    Vandas, Steve

    1998-01-01

    Focuses on hurricanes and tsunamis and uses these topics to address other parts of the science curriculum. In addition to a discussion on beach erosion, a poster is provided that depicts these natural hazards that threaten coastlines. (DDR)

  20. Hazardous Waste

    MedlinePlus

    ... wastes come from products in our homes. Our garbage can include such hazardous wastes as old batteries, ... drain, flush them, or put them in the garbage. See if you can donate or recycle. Many ...

  1. Reproductive Hazards

    MedlinePlus

    ... and female reproductive systems play a role in pregnancy. Problems with these systems can affect fertility and ... a reproductive hazard can cause different effects during pregnancy, depending on when she is exposed. During the ...

  2. Nanocomposite polymer electrolytes: Modulation of mechanical properties using surface-functionalized fumed silica

    NASA Astrophysics Data System (ADS)

    Yerian, Jeffrey Alan

    Rechargeable lithium metal batteries are potential next-generation power sources for portable electronic devices and electric vehicles due to their high-energy density and low self-discharge rate. However, high reactivity of lithium metal with the electrolyte impedes commercialization. Improved performance of the electrolyte can be achieved by adding surface-functionalized fumed silica to enhance mechanical stability and reduce reactivity with lithium metal. Crosslinkable fumed silica in polyethylene glycol dimethyl ether (PEGdm, Mn = 250) + lithium bis(trifluoromethanesulfonyl)imide can be subsequently reacted in the presence of a chemically similar monomer, e.g., butyl methacrylate (BMA) monomer, to form covalent bonds between silica particles rather than physical interactions. The conductivity decreases by only a factor of two after crosslinking with 20 wt% BMA despite significant increases in elastic modulus (G'). These electrolytes exhibit room-temperature conductivity near 10-3 S cm-1 , G' greater than 10 5 Pa, and a yield stress approaching 104 Pa. Addition of fumed silica to polyethylene oxide (PEO, MW = 200K) increases G'; decreases the frequency dependence of G'; and increases percent recoverable strain. The extent of elasticity enhancement depends on fumed silica surface chemistry and concentration. The largest increase in elasticity is observed for hydrophilic silica due to interactions between hydroxyl groups on the silica and ether oxygens on PEO. These interactions facilitate bridging of fumed silica particles through entanglements of adsorbed PEO, which increases G '. Hydrophilic and hydrophobic blends of fumed silica are studied in mineral oil and PEGdm (250) to determine how the presence of two silica types affects the strength and mechanism of gel formation. In mineral oil, blends exhibit G' between those of single-component systems since both hydrophilic and hydrophobic fumed silica interacts via hydrogen bonding. Consequently, G' of blend

  3. A Novel Method for Assessing Respiratory Deposition of Welding Fume Nanoparticles

    PubMed Central

    Cena, L. G.; Keane, M. J.; Chisholm, W. P.; Stone, S.; Harper, M.; Chen, B. T.

    2016-01-01

    Welders are exposed to high concentrations of nanoparticles. Compared to larger particles, nanoparticles have been associated with more toxic effects at the cellular level, including the generation of more reactive oxygen species activity. Current methods for welding-fume aerosol exposures do not differentiate between the nano-fraction and the larger particles. The objectives of this work are to establish a method to estimate the respiratory deposition of the nano-fraction of selected metals in welding fumes and test this method in a laboratory setting. Manganese (Mn), Nickel (Ni), Chromium (Cr), and hexavalent chromium (Cr(VI)) are commonly found in welding fume aerosols and have been linked with severe adverse health outcomes. Inductively coupled plasma mass spectrometry (ICP-MS) and ion chromatography (IC) were evaluated as methods for analyzing the content of Mn, Ni, Cr, and Cr(VI) nanoparticles in welding fumes collected with nanoparticle respiratory deposition (NRD) samplers. NRD samplers collect nanoparticles at deposition efficiencies that closely resemble physiological deposition in the respiratory tract. The limits of detection (LODs) and quantitation (LOQs) for ICP-MS and IC were determined analytically. Mild and stainless steel welding fumes generated with a robotic welder were collected with NRD samplers inside a chamber. LODs (LOQs) for Mn, Ni, Cr, and Cr(VI) were 1.3 μg (4.43 μg), 0.4 μg (1.14 μg), 1.1 μg (3.33 μg), and 0.4 μg (1.42 μg), respectively. Recovery of spiked samples and certified welding fume reference material was greater than 95%. When testing the method, the average percentage of total mass concentrations collected by the NRD samplers was ~30% for Mn, ~50% for Cr, and ~60% for Ni, indicating that a large fraction of the metals may lie in the nanoparticle fraction. This knowledge is critical to the development of toxicological studies aimed at finding links between exposure to welding fume nanoparticles and adverse health

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

    SciTech Connect

    Antonini, James M. . E-mail: jga6@cdc.gov; Taylor, Michael D.; Millecchia, Lyndell; Bebout, Alicia R.; Roberts, Jenny R.

    2004-11-01

    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 10{sup 3} 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-{alpha} (TNF-{alpha}), 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-{alpha}, IL-6, and IL-10 after infection. In conclusion, pretreatment with MMA-SS increased production of NO and proinflammatory cytokines (TNF-{alpha} and IL-6) after infection, which are likely

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

    PubMed

    Antonini, James M; Taylor, Michael D; Millecchia, Lyndell; Bebout, Alicia R; Roberts, Jenny R

    2004-11-01

    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 10(3) 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-alpha (TNF-alpha), 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-alpha, IL-6, and IL-10 after infection. In conclusion, pretreatment with MMA-SS increased production of NO and proinflammatory cytokines (TNF-alpha and IL-6) after infection, which are likely responsible for

  6. A novel method for assessing respiratory deposition of welding fume nanoparticles.

    PubMed

    Cena, L G; Keane, M J; Chisholm, W P; Stone, S; Harper, M; Chen, B T

    2014-01-01

    Welders are exposed to high concentrations of nanoparticles. Compared to larger particles, nanoparticles have been associated with more toxic effects at the cellular level, including the generation of more reactive oxygen species activity. Current methods for welding-fume aerosol exposures do not differentiate between the nano-fraction and the larger particles. The objectives of this work are to establish a method to estimate the respiratory deposition of the nano-fraction of selected metals in welding fumes and test this method in a laboratory setting. Manganese (Mn), Nickel (Ni), Chromium (Cr), and hexavalent chromium (Cr(VI)) are commonly found in welding fume aerosols and have been linked with severe adverse health outcomes. Inductively coupled plasma mass spectrometry (ICP-MS) and ion chromatography (IC) were evaluated as methods for analyzing the content of Mn, Ni, Cr, and Cr(VI) nanoparticles in welding fumes collected with nanoparticle respiratory deposition (NRD) samplers. NRD samplers collect nanoparticles at deposition efficiencies that closely resemble physiological deposition in the respiratory tract. The limits of detection (LODs) and quantitation (LOQs) for ICP-MS and IC were determined analytically. Mild and stainless steel welding fumes generated with a robotic welder were collected with NRD samplers inside a chamber. LODs (LOQs) for Mn, Ni, Cr, and Cr(VI) were 1.3 μg (4.43 μg), 0.4 μg (1.14 μg), 1.1 μg (3.33 μg), and 0.4 μg (1.42 μg), respectively. Recovery of spiked samples and certified welding fume reference material was greater than 95%. When testing the method, the average percentage of total mass concentrations collected by the NRD samplers was ~30% for Mn, ~50% for Cr, and ~60% for Ni, indicating that a large fraction of the metals may lie in the nanoparticle fraction. This knowledge is critical to the development of toxicological studies aimed at finding links between exposure to welding fume nanoparticles and adverse health

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

    SciTech Connect

    Ghosh, D.

    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.

  8. ALTERATIONS IN CARDIOMYOCYTE FUNCTION AFTER PULMONARY TREATMENT WITH STAINLESS STEEL WELDING FUME IN RATS

    PubMed Central

    Popstojanov, Risto; Antonini, James M.; Salmen, Rebecca; Ye, Morgan; Zheng, Wen; Castranova, Vincent; Fekedulegn, Desta B.; Kan, Hong

    2015-01-01

    Welding fume is composed of a complex of different metal particulates. Pulmonary exposure to different welding fumes may exert a negative impact on cardiac function, although the underlying mechanisms remain unclear. To explore the effect of welding fumes on cardiac function, Sprague-Dawley rats were exposed by intratracheal instillation to 2 mg/rat of manual metal arc hard surfacing welding fume (MMA-HS) once per week for 7 wk. Control rats received saline. Cardiomyocytes were isolated enzymatically at d 1 and 7 postexposure. Intracellular calcium ([Ca2+]i) transients (fluorescence ratio) were measured on the stage of an inverted phase-contrast microscope using a myocyte calcium imaging/cell length system. Phosphorylation levels of cardiac troponin I (cTnI) were determined by Western blot. The levels of nonspecific inflammatory marker C-reactive protein (CRP) and proinflammatory cytokine interleukin-6 (IL-6) in serum were measured by enzyme-linked immunosorbent assay (ELISA). Contraction of isolated cardiomyocytes was significantly reduced at d 1 and d 7 postexposure. Intracellular calcium levels were decreased in response to extracellular calcium stimulation at d 7 postexposure. Changes of intracellular calcium levels after isoprenaline hydrochloride (ISO) stimulation were not markedly different between groups at either time point. Phosphorylation levels of cTnI in the left ventricle were significantly lower at d 1 post-exposure. The serum levels of CRP were not markedly different between groups at either time point. Serum levels of IL-6 were not detectable in both groups. Cardiomyocyte alterations observed after welding fume treatment were mainly due to alterations in intracellular calcium handling and phosphorylation levels of cTnI. PMID:24786677

  9. Total fume and metal concentrations during welding in selected factories in Jeddah, Saudi Arabia.

    PubMed

    Balkhyour, Mansour Ahmed; Goknil, Mohammad Khalid

    2010-07-01

    Welding is a major industrial process used for joining metals. Occupational exposure to welding fumes is a serious occupational health problem all over the world. The degree of risk to welder's health from fumes depends on composition, concentration, and the length of exposure. The aim of this study was to investigate workers' welding fume exposure levels in some industries in Jeddah, Saudi Arabia. In each factory, the air in the breathing zone within 0.5 m from welders was sampled during 8-hour shifts. Total particulates, manganese, copper, and molybdenum concentrations of welding fumes were determined. Mean values of eight-hour average particulate concentrations measured during welding at the welders breathing zone were 6.3 mg/m(3) (Factory 1), 5.3 mg/m(3) (Factory 2), 11.3 mg/m(3) (Factory 3), 6.8 mg/m(3) (Factory 4), 4.7 mg/m(3) (Factory 5), and 3.0 mg/m(3) (Factory 6). Mean values of airborne manganese, copper, and molybdenum levels measured during welding were in the range of 0.010 mg/m(3)-0.477 mg/m(3), 0.001 mg/m(3)-0.080 mg/m(3) and 0.001 mg/m(3)-0.058 mg/m(3) respectively. Mean values of calculated equivalent exposure values were: 1.50 (Factory 1), 1.56 (Factory 2), 5.14 (Factory 3), 2.21 (Factory 4), 2.89 (Factory 5), and 1.20 (Factory 6). The welders in factories 1, 2, 3, and 4 were exposed to welding fume concentration above the SASO limit value, which may increase the risk of respiratory health problems. PMID:20717553

  10. Dynamic effects on containment of air-curtain fume hood operated with heat source.

    PubMed

    Chen, Jia-Kun; Huang, Rong Fung; Hsin, Pei-Yi

    2012-01-01

    This study focused on the leakage characteristics of the air-curtain fume hood that are subject to the influences of sash movement and walk-by motion while a high temperature heat source was operated in the hood. The flow visualization and trace gas test method were used to investigate the performance of the air-curtain fume hood. An electric heater was placed in the hood to simulate the heat source. The temperature of the heat source installed inside the air-curtain fume hood varied between 180°C and 300°C. Trace gas tests following the dynamic test methods of EN-14175 protocol were employed to measure the spillages of sulfur hexafluoride gas that were released in the hood. When subject to the influence of sash movement at a heat source temperature lower than 260°C, the leakage level was high at the suction velocity V(s) < 8 m/sec but was negligibly small at V(s) > 10 m/sec. When subject to the influence of people walk-by, the leakage level was relatively low at the suction velocity larger than 8 m/sec at sash height H = 50 cm. The height of the sash opening was a crucial parameter for the containment of the air-curtain fume hood. At the sash opening lower than about 25 cm, suction velocity less than or equal to 6 m/sec was enough to make the sulfur hexafluoride leakage less than the threshold value, 0.65 ppm, suggested by the BG Chemie. The air-curtain fume hood presented a great performance to resist the effect of drafts even though there was a high temperature heat source working in the hood. PMID:23009207

  11. [Inhalation exposure to welding fumes of arc welders in processing Cr-Ni steel in large chemical industry].

    PubMed

    Dyrba, B C; Richter, K H

    1989-05-01

    For clearing up the inhalative load by welding fumes and gases of arc welders in industrial workshops mainly working on Cr-Ni-steels the following welding processes were studied: tungsten inert-gas (TIG), electrode-by-hand (EH), metal inert-gas (MIG), and plasma cutting (plasma). From the total load by welding fumes follows the rank TIG less than EH less than plasma less than MIG. Observing the maximum allowable concentration (MACD) for the total welding fume, no MACD for Cr and Ni was found exceeded. Regarding the welding gases ozone and CO no limit values were exceeded. From the results conclusions were made. PMID:2750235

  12. 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

    PubMed Central

    2010-01-01

    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 MMP9. Conclusions

  13. [Evaluation of exposure to fumes arising during welding of non-alloyed and low-alloyed steel by various methods].

    PubMed

    Matczak, W; Chmielnicka, J

    1988-01-01

    Evaluated in the paper is welders' exposure to fumes resulting from welding of nonalloyed and low-alloyed steel, whether pure or coated with protective layers, using two most popular welding techniques for those types of steel, i.e. metal active gas welding (MAG) and manual welding with covered electrode (MMA). Due to different chemical composition of fumes at particular workstations, the proper hygienic evaluation was based on measurements of individual concentrations of fumes in workers' breathing zone. A considerable contribution of the combined exposure was yielded by such fume constituents as manganese, ferrum and zinc (welding of steel coated with zinc protective layers), also chromium (welding of low- and -highalloyed steel), as well as copper (metal gas welding). The highest combined exposure (10-fold allowable value) was that of welders of steel coated with the zinc layer, using the metal active gas welding. PMID:3237059

  14. Prediction of Flexural Strength of Concretes Containing Silica Fume and Styrene-Butadiene Rubber (SBR) with an Empirical Model

    NASA Astrophysics Data System (ADS)

    Shafieyzadeh, M.

    2015-12-01

    In the flexural test, the theoretical maximum tensile stress at the bottom fiber of a test beam is known as the modulus of rupture or flexural strength. This work deals with the effects of Silica Fume and Styrene-Butadiene Latex (SBR) on flexural strength of concrete. An extensive experimentation was carried out to determine the effects of silica fume and SBR on flexural strength of concrete. Two water-binder ratios and several percentages of silica fume and SBR were considered. Abrams' Law, which was originally formulated for conventional concrete containing cement as the only cementations material, is used for prediction of flexural strength of these concretes. The aim of this work is to construct an empirical model to predict the flexural strength of silica fume-SBR concretes using concrete ingredients and time of curing in water. Also, the obtained results for flexural strength tests have been compared with predicted results.

  15. Influence of silica fume on the immobilization properties of cementitious mortars exposed to freeze-thaw cycles

    SciTech Connect

    Quaresima, R.; Scoccia, G.; Volpe, R.; Medici, F.; Merli, C.

    1996-12-31

    This study deals with the durability of immobilization matrices, drawing comparisons among the release characteristics of cementitious mortars with or without silica fume, before and after freezing-thawing cycles. Three different dosages of silica fume have been experimented, using silica fume as a substitute of cement. The results obtained from the leaching tests have emphasized, in all the matrices which had undergone the freeze-thaw cycles, an increase of the percentage of tracer released with respect to the same matrices before the freezing-thawing cycles. As a consequence of the freezing-thawing cycles, the velocity of release has also increased in all the experimented matrices. However, the tests have reconfirmed the positive effect of the addition of silica fume.

  16. 42 CFR 84.1141 - Isoamyl acetate tightness test; dust, fume, and mist respirators designed for respiratory...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... contamination level not less than 0.05 milligram per cubic meter; minimum requirements. 84.1141 Section 84.1141... protection against fumes of various metals having an air contamination level not less than 0.05 milligram...

  17. 42 CFR 84.1141 - Isoamyl acetate tightness test; dust, fume, and mist respirators designed for respiratory...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... contamination level not less than 0.05 milligram per cubic meter; minimum requirements. 84.1141 Section 84.1141... protection against fumes of various metals having an air contamination level not less than 0.05 milligram...

  18. 42 CFR 84.1141 - Isoamyl acetate tightness test; dust, fume, and mist respirators designed for respiratory...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... contamination level not less than 0.05 milligram per cubic meter; minimum requirements. 84.1141 Section 84.1141... protection against fumes of various metals having an air contamination level not less than 0.05 milligram...

  19. 42 CFR 84.1141 - Isoamyl acetate tightness test; dust, fume, and mist respirators designed for respiratory...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... contamination level not less than 0.05 milligram per cubic meter; minimum requirements. 84.1141 Section 84.1141... protection against fumes of various metals having an air contamination level not less than 0.05 milligram...

  20. 42 CFR 84.1141 - Isoamyl acetate tightness test; dust, fume, and mist respirators designed for respiratory...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... contamination level not less than 0.05 milligram per cubic meter; minimum requirements. 84.1141 Section 84.1141... protection against fumes of various metals having an air contamination level not less than 0.05 milligram...

  1. Ignition Delays of Alkyl Thiophosphites with White and Red Fuming Nitric Acids Within Temperature Range 80 to -105 F

    NASA Technical Reports Server (NTRS)

    Miller, Riley O; Ladanyi, Dezso J

    1953-01-01

    Ignition delays of alkyl thiophosphites were obtained in a modified open-cup apparatus and a small-scale rocket engine apparatus. At -40 F, mixed alkyl thiophosphites gave short delays with white fuming nitric acid containing 2 percent water and red fuming nitric acids of widely varying compositions. At -40 F and higher, triethyl trithiophosphite blended with as much as 40 percent n-heptane gave satisfactory self-igniting properties at temperatures as low as -76 F.

  2. Inhalation exposure of rats to asphalt fumes generated at paving temperatures alters pulmonary xenobiotic metabolism pathways without lung injury.

    PubMed Central

    Ma, Jane Y C; Rengasamy, Apavoo; Frazer, Dave; Barger, Mark W; Hubbs, Ann F; Battelli, Lori; Tomblyn, Seith; Stone, Samuel; Castranova, Vince

    2003-01-01

    Asphalt fumes are complex mixtures of various organic compounds, including polycyclic aromatic hydrocarbons (PAHs). PAHs require bioactivation by the cytochrome P-450 monooxygenase system to exert toxic/carcinogenic effects. The present study was carried out to characterize the acute pulmonary inflammatory responses and the alterations of pulmonary xenobiotic pathways in rats exposed to asphalt fumes by inhalation. Rats were exposed at various doses and time periods to air or to asphalt fumes generated at paving temperatures. To assess the acute damage and inflammatory responses, differential cell counts, acellular lactate dehydrogenase (LDH) activity, and protein content of bronchoalveolar lavage fluid were determined. Alveolar macrophage (AM) function was assessed by monitoring generation of chemiluminescence and production of tumor necrosis factor-alpha and interleukin-1. Alteration of pulmonary xenobiotic pathways was determined by monitoring the protein levels and activities of P-450 isozymes (CYP1A1 and CYP2B1), glutathioneS-transferase (GST), and NADPH:quinone oxidoreductase (QR). The results show that acute asphalt fume exposure did not cause neutrophil infiltration, alter LDH activity or protein content, or affect AM function, suggesting that short-term asphalt fume exposure did not induce acute lung damage or inflammation. However, acute asphalt fume exposure significantly increased the activity and protein level of CYP1A1 whereas it markedly reduced the activity and protein level of CYP2B1 in the lung. The induction of CYP1A1 was localized in nonciliated bronchiolar epithelial (Clara) cells, alveolar septa, and endothelial cells by immunofluorescence microscopy. Cytosolic QR activity was significantly elevated after asphalt fume exposure, whereas GST activity was not affected by the exposure. This induction of CYP1A1 and QR with the concomitant down-regulation of CYP2B1 after asphalt fume exposure could alter PAH metabolism and may lead to potential

  3. A short-term test adapted to detect the genotoxic effects of environmental volatile pollutants (benzene fumes) using the filamentous fungus Aspergillus nidulans.

    PubMed

    Domingues Zucchi, Tiago; Domingues Zucchi, Fernando; Poli, Paola; Soares de Melo, Itamar; Zucchi, Tania M A D

    2005-06-01

    With the recent focus on environmental problems, increasing awareness of the harmful effects of industrial and agricultural pollution has created a demand for progressively more sophisticated pollutant and toxicity detection methods. Using Aspergillus nidulans strains this work presents a new short term-test that, most importantly, enables the rapid and inexpensive detection of volatile pollutants that induce genotoxic/carcinogenic effects in animals. The main aim is to contribute to environmental health protection, and special attention is directed to monitoring the hazard posed by benzene (as a carcinogenic agent model) mainly because its ubiquitous presence often leads to severe noxious effects in humans among whom increased rates of human leukemia have been reported. To evaluate even the submutagenic effects of benzene fumes, two Aspergillus nidulans diploid strains, heterozygous for several auxotrophic mutations, were used. The DNA lesions produced stimulate mitotic recombination and homozygotization of auxotrophic recessive mutations. Conidial exposure to a saturated atmosphere of benzene fumes for 20 s was enough to increase the mitotic recombination frequencies significantly. Genetic analyses of treated diploids evidenced alterations related to mitotic recombination frequencies, gene expression, and allelic segregation rates. Altogether they reflect the potential of benzene to induce alterations in the fungal DNA, and albeit indirectly, they also respond for the genotoxic/carcinogenic harmful side effects widely connected to benzene. This is the first description of a sensitive, rapid and inexpensive test able to detect the submutagenic dose effects of volatile environmental compounds. In addition, despite concentrating on benzene the same test can be applied to many other pollutants, volatile or not. Additionally, the test can also be used to detect the antigenotoxic properties of foods and drugs. PMID:15931421

  4. Personal exposure to metal fume, NO2, and O3 among production welders and non-welders.

    PubMed

    Schoonover, Todd; Conroy, Lorraine; Lacey, Steven; Plavka, Julie

    2011-01-01

    The objective of this study was to characterize personal exposures to welding-related metals and gases for production welders and non-welders in a large manufacturing facility. Welding fume metals and irritant gases nitrogen dioxide (NO(2)) and ozone (O(3)) were sampled for thirty-eight workers. Personal exposure air samples for welding fume metals were collected on 37 mm open face cassettes and nitrogen dioxide and ozone exposure samples were collected with diffusive passive samplers. Samples were analyzed for metals using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and welding fume metal exposure concentrations were defined as the sum of welding-related metals mass per volume of air sampled. Welding fume metal exposures were highly variable among similar types of welding while NO(2) and O(3) exposure were less variable. Welding fume metal exposures were significantly higher 474 μg/m(3) for welders than non-welders 60 μg/m(3) (p=0.001). Welders were exposed to higher concentrations of NO(2) and O(3) than non-welders but the differences were not statistically significant. Welding fume metal exposure concentrations for welders performing gas metal arc welding (GMAW) and shielded metal arc welding (SMAW) were higher than welders performing gas tungsten arc welding (GTAW). Non-welders experienced exposures similar to GTAW welders despite a curtain wall barrier separating welding and non-welding work areas. PMID:20823632

  5. Installation of a flow control device in an inclined air-curtain fume hood to control wake-induced exposure.

    PubMed

    Chen, Jia-Kun

    2016-08-01

    An inclined plate for flow control was installed at the lower edge of the sash of an inclined air-curtain fume hood to reduce the effects of the wake around a worker standing in front of the fume hood. Flow inside the fume hood is controlled by the inclined air-curtain and deflection plates, thereby forming a quad-vortex flow structure. Controlling the face velocity of the fume hood resulted in convex, straight, concave, and attachment flow profiles in the inclined air-curtain. We used the flow visualization and conducted a tracer gas test with a mannequin to determine the performance of two sash geometries, namely, the half-cylinder and inclined plate designs. When the half-cylinder design was used, the tracer gas test registered a high leakage concentration at Vf ≦ 57.1 fpm or less. This concentration occurred at the top of the sash opening, which was close to the breathing zone of the mannequin placed in front of the fume hood. When the inclined plate design was used, the containment was good, with concentrations of 0.002-0.004 ppm, at Vf ≦ 63.0 fpm. Results indicate that an inclined plate effectively reduces the leakage concentration induced by recirculation flow structures that form in the wake of a worker standing in front of an inclined air-curtain fume hood. PMID:26950527

  6. Reduced worker exposure and improved energy efficiency in industrial fume-hoods using an airvest

    SciTech Connect

    Gadgil, A.J.; Faulkner, D.; Fisk, W.J.

    1992-05-01

    Reduction in the breathing zone concentration of an experimentally simulated pollutant, by factors ranging from 100 to 800, was observed with the device (called an airvest). With use of the airvest by the worker, the hood face velocity can be reduced, leading to substantial energy savings in conditioning of make up air in the building. The airvest works by elimination or ventilation of the eddy that develops in front of a worker when the worker stands in the open face of a fume hood. Normally this eddy draws some of the pollutant (commonly generated near and in front of the worker) towards the worker`s breathing zone. Experiments sing a heated full-size mannequin were conducted with a full scale walk-in fume hood. Sulfur hexafluoride was used to simulate pollutant generation and exposure during a work situation. Flow visualization with smoke was also undertaken to evaluate the airvest qualitatively. 3 refs.

  7. Combustion fume structure and dynamics. Period of performance, August 16, 1990--September 15, 1991

    SciTech Connect

    Flagan, R.C.

    1991-12-31

    The focus of this research program is on elucidating the fundamental processes that determine the particle size distribution, comparison, and agglomerate structures of coal ash fumes. The ultimate objective of this work is the development and validation of a model for the dynamics of combustion fumes, describing both the evolution of the particle size distribution and the particle morphology. The study employs model systems to address the fundamental questions and to provide rigorous validation of the models to be developed. This first phase of the project has been devoted to the development of a detailed experimental strategy that will allow agglomerates with a broad range of fractal dimensions to be studied in the laboratory.

  8. Immobilization of enzymes on fumed silica nanoparticles for applications in nonaqueous media.

    PubMed

    Cruz, Juan C; Würges, Kerstin; Kramer, Martin; Pfromm, Peter H; Rezac, Mary E; Czermak, Peter

    2011-01-01

    Enzymatic catalysis in nonaqueous media is considered as an attractive tool for the preparation of a variety of organic compounds of commercial interest. This approach is advantageous for numerous reasons including the enhanced stability of some substrates and products in solvents, sometimes improved selectivity of the enzyme, and reduction of unwanted water-dependent side reactions since little water is present. Due to the poor solubility of enzymes in these media, mass transfer limitations are sometimes present, leading to low apparent catalytic activity. Immobilization on solid supports has been successfully applied to overcome enzyme solubility issues by increasing the accessibility of substrates to the enzymes' active sites. We have developed a simple immobilization protocol that uses fumed silica as support. Fumed silica is an inexpensive nanostructured material with unique properties including large surface area and exceptional adsorptive affinity for organic macromolecules. Our protocol is performed in two main steps. First, the enzyme molecules are physically adsorbed on the surface of the non-porous fumed silica nanoparticles with the participation of silanol groups (Si-OH) and second, water is removed by lyophilization. The protocol has been successfully applied to both s. Carlsberg and Candida antarctica lipase B (CALB). The resulting fumed silica-based nanobiocatalysts of these two enzymes were tested for catalytic activity in hexane. The transesterification of N-acetyl-L: -phenylalanine ethyl ester was the model reaction for s. Carlsberg nanobiocatalysts. The simple esterification of geraniol and the enantioselective transesterification of (RS)-1-phenylethanol were the model reactions for CALB nanobiocatalysts. The observed catalytic activities were remarkably high and even exceeded those of commercially available preparations. PMID:21553189

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

    NASA Technical Reports Server (NTRS)

    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.

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

    SciTech Connect

    Roberson, P.W.

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

    NASA Astrophysics Data System (ADS)

    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.

  12. Contraction-free, fume-fixed longitudinal sections of fresh frozen muscle

    NASA Technical Reports Server (NTRS)

    Riley, Danny A.; Slocum, Glenn R.

    1988-01-01

    Contraction damage occurring when longitudinal frozen sections of fresh unfixed muscles are thawed on microscope slides has limited histological examination of this tissue mainly to cross sections. Longitudinally oriented sections are advantageous for investigating properties that vary along the length of the muscle fibers. A fume fixation technique has been developed for preventing contraction of thick longitudinal frozen sections. The technique is compatible with histochemical staining of enzymes.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    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

  15. Increased levels of oxidative DNA damage attributable to cooking-oil fumes exposure among cooks.

    PubMed

    Ke, Yuebin; Cheng, Jinquan; Zhang, Zhicheng; Zhang, Renli; Zhang, Zhunzhen; Shuai, Zhihong; Wu, Tangchun

    2009-07-01

    Previous investigations have indicated that cooks are exposed to polycyclic aromatic hydrocarbons (PAHs) from cooking-oil fumes. However, Emission of PAH and their carcinogenic potencies from cooking oil fumes sources have not been investigated among cooks. To investigate the urinary excretion of a marker for oxidative DNA damage, 8-hydroxydeoxyguanosine (8-OHdG), in different groups of cooks and different exposure groups, and to study the association between 8-OHdG and 1-hydroxypyrene(1-OHP), a biological marker for PAH exposure. Urine samples were collected from different groups of cooks (n = 86) and from unexposed controls (n = 36); all were male with similar age and smoking habits. The health status, occupational history, smoking, and alcohol consumption 24 h prior to sampling was estimated from questionnaires. The urine samples were frozen for later analyses of 8-OHdG and 1-OHP levels by high-performance liquid chromatography. Excretion in urine of 8-OHdG was similar for controls (mean 1.2micromol/mol creatinine, n = 36), and for those who had been in the kitchen with an exhaust-hood operating (mean 1.5micromol/mol creatinine, n = 45). Cooks exposed to cooking-oil fumes without exhaust-hood operation had significantly increased excretion of 8-OHdG (mean 2.3micromol/mol creatinine, n = 18), compared with controls. The urinary levels of ln 1-OHP and ln 8-OHdG were still significantly correlated in a multiple regression analysis. The results indicate that exposure to PAH or possibly other compounds in cooking-oil fumes may cause oxidative DNA damage. PMID:19225966

  16. Evaluation of worker exposure to asphalt roofing fumes: influence of work practices and materials.

    PubMed

    Kriech, Anthony J; Osborn, Linda V; Trumbore, David C; Kurek, Joseph T; Wissel, Herbert L; Rosinski, Klaus D

    2004-02-01

    A field study was conducted on 42 asphalt-roofing workers at 7 built-up roofing sites across the United States. Sixteen out of 42 samples show levels of exposure to asphalt fumes that exceed the current American Conference of Governmental Industrial Hygienists' (ACGIH)-recommended threshold limit value of 0.5 mg/m(3) as benzene extractable inhalable particulate. Statistically, the geometric mean of all 42 worker samples was 0.27 mg/m(3) (geometric standard deviation = 3.40), the average was 0.70 mg/m(3) (standard deviation = 1.69) and the median value was 0.24 mg/m(3). The impact of work practices is discussed including the use of a novel product that uses a polymer skin to reduce fumes from built up roofing asphalt. Its use resulted in a reduction of benzene soluble matter (BSM) of >70%. Other testing measures utilized included total particulate matter, total organic matter, simulated distillation, and fluorescence analysis. Additionally, a controlled pilot study using 16 kettle-area and 16 worker samples clearly showed that when the temperature of the kettle was reduced by 28 degrees C, there was a 38-59% reduction in fume exposure and a 54% reduction in fluorescence with standard asphalts. Reduction of BSM exposures using fuming-suppressed asphalt was also confirmed during this pilot plant study (81-92%), with fluorescence lowered by 88%. Confounding agents such as roof tear-off materials were also analyzed and their contribution to worker exposure is discussed. PMID:15204883

  17. Exposure to welding fumes is associated with acute systemic inflammatory responses

    PubMed Central

    Kim, J; Chen, J; Boyce, P; Christiani, D

    2005-01-01

    Aims: To investigate the acute systemic inflammatory response to welding fume exposure. Methods: Twenty four welders (42% smokers) and 13 non-exposed controls (23% smokers) were monitored at a welding school. Exposure to fine particulate matter (PM2.5) was assessed using cyclone samplers. Markers of systemic inflammation, including C-reactive protein (CRP), fibrinogen, and white blood cell (WBC) levels, were determined in peripheral blood samples collected at baseline and after 5.3 (SD 1.0) hours of exposure. Results: The median PM2.5 concentration for welders was 1.66 mg/m3, which was significantly greater than that for controls (0.04 mg/m3). Compared to non-smokers, smokers had a significantly higher baseline WBC count, but comparable levels of CRP and fibrinogen. In non-smokers, welding fume exposure was associated with a significant increase in WBC and neutrophil counts immediately following exposure (+0.8x103/µl, 95% CI 0.1 to 1.6, and +1.0x103/µl, 95% CI 0.4 to 1.7, respectively). A significant decrease in fibrinogen levels was observed in non-smokers (–32 mg/dl, 95% CI –63 to –1). No significant changes in WBC, neutrophil, and fibrinogen levels were found in smokers. Sixteen hours after welding exposure, CRP levels were found to be significantly increased in both non-smokers and smokers (0.90 mg/l, 95% CI 0.17 to 1.64). PM2.5 concentrations were found to be significantly associated with absolute neutrophil counts in non-smokers, and CRP levels in both non-smokers and smokers. Conclusions: High levels of welding fume exposure induce acute systemic inflammation in a relatively young, healthy working population. These results also suggest that smoking may modify the effect of welding fume exposure on specific inflammatory markers. PMID:15723880

  18. Characteristics of PAHs from deep-frying and frying cooking fumes.

    PubMed

    Yao, Zhiliang; Li, Jing; Wu, Bobo; Hao, Xuewei; Yin, Yong; Jiang, Xi

    2015-10-01

    Cooking fumes are an important indoor source of polycyclic aromatic hydrocarbons (PAHs). Because indoor pollution has a more substantial impact on human health than outdoor pollution, PAHs from cooking fumes have drawn considerable attention. In this study, 16 PAHs emitted through deep-frying and frying methods using rapeseed, soybean, peanut, and olive oil were examined under a laboratory fume hood. Controlled experiments were conducted to collect gas- and particulate-phase PAHs emitted from the cooking oil fumes, and PAH concentrations were quantified via high-performance liquid chromatography (HPLC). The results show that deep-frying methods generate more PAHs and benzo[a]pyrene (B[a]P) (1.3 and 10.9 times, respectively) because they consume greater volumes of edible oil and involve higher oil temperatures relative to those of frying methods. In addition, the total B[a]Peq concentration of deep-frying is 2.2-fold larger than that of frying. Regarding the four types of edible oils studied, rapeseed oil produced more PAH emission than the other three oil varieties. For all of the cooking tests, three- and four-ringed PAHs were the main PAH components regardless of the food and oil used. Concerning the PAH partition between gas and particulate phase, the gaseous compounds accounted for 59-96 % of the total. Meanwhile, the particulate fraction was richer of high molecular weight PAHs (five-six rings). Deep-frying and frying were confirmed as important sources of PAH pollution in internal environments. The results of this study provide additional insights into the polluting features of PAHs produced via cooking activities in indoor environments. PMID:26066859

  19. Electrospun Ultrafine Fiber Composites Containing Fumed Silica: From Solution Rheology to Materials with Tunable Wetting.

    PubMed

    Dufficy, Martin K; Geiger, Mackenzie T; Bonino, Christopher A; Khan, Saad A

    2015-11-17

    Fumed silica (FS) particles with hydrophobic (R805) or hydrophilic (A150) surface functionalities are incorporated in polyacrylonitrile (PAN) fibers by electrospinning to produce mats with controlled wettability. Rheological measurements are conducted to elucidate the particle-polymer interactions and characterize the system while microscopic and analytic tools are used to examine FS location within both fibers and films to aid in the fundamental understanding of wetting behavior. Unlike traditional polymers, we find these systems to be gel-like, yet electrospinnable; the fumed silica networks break down into smaller aggregates during the electrospinning process and disperse both within and on the surface of the fibers. Composite nanofiber mats containing R805 FS exhibit an apparent contact angle over 130° and remain hydrophobic over 30 min, while similar mats with A150 display rapid surface-wetting with a static contact angle of ∼30°. Wicking experiments reveal that the water absorption properties can be further manipulated, with R805 FS-impregnated mats taking up only 8% water relative to mat weight in 15 min. In contrast, PAN fibers containing A150 FS absorb 425% of water in the same period, even more than the pure PAN fiber (371%). The vastly different responses to water demonstrate the versatility of FS in surface modification, especially for submicron fibrous mats. The role of fumed silica in controlling wettability is discussed in terms of their surface functionality, placement on nanofibers and induced surface roughness. PMID:26477547

  20. Effect of silica fume on the characterization of the geopolymer materials

    NASA Astrophysics Data System (ADS)

    Khater, Hisham M.

    2013-12-01

    The influence of silica fume (SF) addition on properties of geopolymer materials produced from alkaline activation of alumino-silicates metakaolin and waste concrete produced from demolition works has been studied through the measurement of compressive strength, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy (SEM) analysis. Alumino-silicate materials are coarse aggregate included waste concrete and fired kaolin (metakaolin) at 800°C for 3 h, both passing a sieve of 90 μm. Mix specimens containing silica fume were prepared at water/binder ratios in a range of 0.30 under water curing. The used activators are an equal mix of sodium hydroxide and silicate in the ratio of 3:3 wt.%. The control geopolymer mix is composed of metakaolin and waste concrete in an equal mix (50:50, wt.%). Waste concrete was partially replaced by silica fume by 1 to 10 wt.%. The results indicated that compressive strengths of geopolymer mixes incorporating SF increased up to 7% substitution and then decreased up to 10% but still higher than that of the control mix. Results indicated that compressive strengths of geopolymer mixes incorporating SF increases up to 7% substitution and then decreases up to 10% but still higher than the control mix, where 7% SF-digested calcium hydroxide (CH) crystals, decreased the orientation of CH crystals, reduced the crystal size of CH gathered at the interface, and improved the interface more effectively.

  1. Amount and distribution of fume contaminants in the lungs of an arc welder post mortem.

    PubMed Central

    Kalliomäki, P L; Sutinen, S; Kelhä, V; Lakomaa, E; Sortti, V; Sutinen, S

    1979-01-01

    This study describes various post-mortem examinations of the lungs of a shipyard arc welder. These investigations comprised morphological methods, including gross pathology and radiography, histological and ultrastructural examinations, chemical analysis of lung tissue, and sensitive magnetic measurements, which can now be used to detect magnetic contaminants, such as welding fume, in human tissue. Such methods can also show the distribution of contaminants. The amount of welding-fume contaminants was low, only 110 mg. The contaminant iron seemed to represent only 10% of the total iron chemically analysed in lung tissue. The concentration of the total iron was 4-10 times higher than that in control tissue. Contaminants tended to collect in the central areas of the lungs. Two concentration centres could be observed in each lung, one anterior and one posterior. There was slight fibrosis around pigmented areas. Histological findings were similar to those of previous studies. Transmission electron micrographs showed that enlarged lysosomes of macrophages contained electron-dense granules, 450 nm to less than 5 nm in diameter, which formed aggregates and short chains, and resembled welding-fume particles in the breathing zone. Our results show the value of studying the same material by a number of inter-related methods. Images PMID:500782

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

    PubMed Central

    Cezar-Vaz, Marta Regina; Bonow, Clarice Alves; Cezar Vaz, Joana

    2015-01-01

    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. PMID:25607606

  3. Risk communication concerning welding fumes for the primary preventive care of welding apprentices in southern Brazil.

    PubMed

    Cezar-Vaz, Marta Regina; Bonow, Clarice Alves; Vaz, Joana Cezar

    2015-01-01

    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. PMID:25607606

  4. Development of a field method for measuring manganese in welding fume.

    PubMed

    Dale Marcy, A; Drake, Pamela L

    2007-11-01

    Workers who perform routine welding tasks are potentially exposed to fume that may contain manganese. Manganese may cause respiratory problems and is implicated in causing the occurrence of Parkinson-like symptoms. In this study, a field colorimetric method for extracting and measuring manganese in welding fume was developed. The method uses ultrasonic extraction with an acidic hydrogen peroxide solution to extract welding fume collected on polyvinyl chloride filters. Commercially available pre-packaged reagents are used to produce a colored solution, created by a reaction of manganese(ii) with 1-(2-pyridylazo)-2-naphthol. Absorbance measurements are then made using a portable spectrophotometer. The method detection limit and limit of quantification (LOQ) were 5.2 microg filter(-1) and 17 microg filter(-1), respectively, with a dynamic range up to 400 microg filter(-1). When the results are above the LOQ for the colorimetric method, the manganese masses are equivalent to those measured by the International Organization for Standardization Method 15202-2, which employs a strong acid digestion and analysis using inductively coupled plasma-optical emission spectrometry. PMID:17968446

  5. Exposure to Cooking Oil Fumes and Oxidative Damages: A Longitudinal Study in Chinese Military Cooks

    PubMed Central

    Lai, Ching-Huang; Jaakkola, Jouni J.K.; Chuang, Chien-Yi; Liou, Saou-Hsing; Lung, Shih-Chun; Loh, Ching-Hui; Yu, Dah-Shyong; Strickland, Paul T.

    2014-01-01

    Cooking oil fumes contain polycyclic aromatic hydrocarbons (PAHs), heterocyclic aromatic amines, benzene, and formaldehyde which may cause oxidative damages to DNA and lipids. We assessed the relations between exposure to cooking oil fumes (COF) and subsequent oxidative DNA damage and lipid peroxidation among military cooks and office-based soldiers. The study population, including 61 Taiwanese male military cooks and a reference group of 37 office soldiers, collected urine samples pre-shift of the first weekday and post-shift of the fifth workday. We measured airborne particulate PAHs in military kitchens and offices and concentrations of urinary 1-OHP, a biomarker of PAH exposure, urinary 8-hydroxydeoxyguanosine (8-OHdG), a biomarkers of oxidative DNA damage, and urinary isoprostane (Isop). Airborne particulate PAHs levels in kitchens significantly exceeded those in office areas. The concentrations of urinary 1-OHP among military cooks increased significantly after 5 days of exposure to COF. Using generalized estimating equation (GEE) analysis adjusting for confounding, a change in log(8-OHdG) and log(Isop) were statistically significantly related to a unit change in log(1-OHP) (regression coefficient [β], β= 0.06, 95% CI 0.001 to 0.12) and (β= 0.07, 95% CI 0.001 to 0.13), respectively. Exposure to PAHs, or other compounds in cooking-oil fumes, may cause both oxidative DNA damage and lipid peroxidation. PMID:22968348

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

    PubMed

    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 <0.25 m s(-1) The angle of the torch relative to the workpiece also has a great deal of influence. To improve efficiency, work station layouts need to favour positions where the torch is held with angles closer to perpendicular (<15°). 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

  7. Development of Welding Fumes Health Index (WFHI) for Welding Workplace’s Safety and Health Assessment

    PubMed Central

    HARIRI, Azian; PAIMAN, Nuur Azreen; LEMAN, Abdul Mutalib; MD. YUSOF, Mohammad Zainal

    2014-01-01

    Abstract Background This study aimed to develop an index that can rank welding workplace that associate well with possible health risk of welders. Methods 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. Results 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. Conclusion 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. PMID:25927034

  8. Kinetics of the zinc slag-Fuming Process: part II. mathematical model

    NASA Astrophysics Data System (ADS)

    Richards, G. G.; Brimacombe, J. K.

    1985-09-01

    A mathematical model of zinc slag fuming has been formulated based on the kinetic conception of the process developed in Part I of this paper. Each of the major reaction zones in the furnace — the slag bath where reduction of zinc oxide and ferric oxide takes place and the tuyere gas column where oxidation of coal and ferrous oxide occurs — have been characterized mathematically. The two zones and the water-jacketed furnace wall have been linked by overall heat and mass balances. Insufficient information is available, however, to characterize quantitatively two of the important kinetic processes occurring in the furnace: the division of coal between entrainment in the slag, combustion in the tuyere gas column and bypass; and oxygen utilization. To overcome this problem the model has been fitted to the data from eleven industrial fuming cycles. Consistent values have been obtained for these kinetic parameters over five different fuming operations indicating that the kinetic conception of the process is sound. The results indicate that about 33 pct of the injected coal is entrained in the slag, 55 pet combusts in the tuyere gas column, and 12 pct bypasses the bath completely. Oxygen utilization has been found to be high and can be correlated to bath depth.

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

    PubMed Central

    Bonthoux, Francis

    2016-01-01

    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 <0.25 m s−1. The angle of the torch relative to the workpiece also has a great deal of influence. To improve efficiency, work station layouts need to favour positions where the torch is held with angles closer to perpendicular (<15°). 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

  10. Mock-up and testing of a variable volume laboratory fume hood exhaust system

    SciTech Connect

    Vresk, J.; Hirsch, P. R.; Davis, S. A.; Myers, G. E.; Woodring, J. L.

    1980-01-01

    A test of an ANL-designed variable volume system prototype used to displace an existing constant volume fume hood ventilation system in a laboratory of the Materials Science Division is described. Performance characteristics such as response, stability, repeatability and hood containment were tested and evaluated, with particular emphasis on containment, to clearly demonstrate that operator safety and the environment are not compromised. Results obtained clearly indicate the feasibility of implementing the prototype concept. The variable volume system enables reducing conditioned ventilation air to the laboratory room by at least 50%, dependent solely upon internal heat loads. Normal hood exhaust of 200 CFM with the face sash in a closed position can be provided by air used to condition building offices and corridors. In all modes of operation, i.e., fume hood face sash closed to fully open, the building differential pressure design criteria from office to corridor to laboratory to fume hood is maintained. Also, hood face velocity can be established to meet minimum requirements at any position of sash opening and test results indicate a hood containment efficiency equal to or better than the presently existing constant volume proportional by-pass system.

  11. Development and evaluation of an air-curtain fume cabinet with considerations of its aerodynamics.

    PubMed

    Huang, R F; Wu, Y D; Chen, H D; Chen, C-C; Chen, C-W; Chang, C-P; Shih, T-S

    2007-03-01

    In order to avoid the inherent aerodynamic difficulties of the conventional fume hood, an innovative design--the 'air curtain-isolated fume hood' is developed. The new hood applies a specially designed air curtain (which is generated by a narrow planar jet and a suction slot flow at low velocities) across the sash plane. The hood constructed for the study is full size and transparent for flow visualization. The aerodynamic characteristics are diagnosed by using the laser-light-sheet-assisted smoke flow visualization method. Four characteristic air-curtain flow modes are identified in the domain of jet and suction velocities when the sash remains static. Some of these characteristic flow modes have much improved flow patterns when compared with those of the conventional fume hoods. From the viewpoint of the aerodynamics and mass transport, the results indicate that the air curtain properly setup across the sash opening allows almost no sensible exchange of momentum and mass between the flowfields of the cabinet and the outside environment. Two standard sulfur hexafluoride (SF6) tracer gas concentration measurement methods following the ANSI/ASHRAE 110-1995 standard and the prEN14175 protocol for static test are employed to examine the contaminant leakage levels. Results of the rigorous examinations of leakage show unusually satisfactory hood performance. The leakage of the tracer gas can approach almost null (<0.001 p.p.m.) if the jet and suction velocities are properly adjusted. PMID:16857702

  12. Room ventilation and its influence on the performance of fume cupboards: A parametric numerical study

    SciTech Connect

    Denev, J.A.; Durst, F.; Mohr, B.

    1997-02-01

    The three-dimensional turbulent flow in a typical chemical laboratory containing two fume cupboards and furniture is investigated numerically in order to obtain detailed information needed for the improved design of ventilating systems for such rooms. The flow inside the two fume cupboards is simulated simultaneously with the room flow, and its dependence on the flow structure in the room is shown. The flow inside the cupboards and in the vicinity of their sash openings has been found to be essentially three-dimensional. Several room parameters are varied, and a quantitative evaluation of their influence on the flow, the comfort characteristics, and the ventilation efficiency is given. Additional ceiling-mounted openings, which extract room air outside the fume cupboards, can affect the capture efficiency of the cupboards, as well as the quality of the air in the room. It has been found also that small changes in the position of the radial inlet ceiling-mounted diffuser can influence the air quality of the room and at the same time the draught risk. These effects are shown for a given room arrangement. To accommodate the complex geometry, the elliptical nature of the mathematical problem, and the use of a turbulence model, a multigrid acceleration method with 245,000 control volumes is used, allowing CPU times on a workstation to become acceptable.

  13. Moral hazard.

    PubMed

    Chambers, David W

    2009-01-01

    Civil societies set aside a common pool of resources to help those with whom chance has dealt harshly. Frequently we allow access to these common resources when bad luck is assisted by foolishness and lack of foresight. Sometimes we may even help ourselves to a few of those common assets since others are doing so and they are public goods, the cost of which is shared and has already been paid. Moral hazard is the questionable ethical practice of increasing opportunity for individual gain while shifting risk for loss to the group. Bailout is an example. What makes moral hazard so widespread and difficult to manage is that it is easier for individuals to see their advantage than it is for groups to see theirs. Runaway American healthcare costs can be explained in these terms. Cheating, overtreatment, commercialism, and other moral problems in dentistry can be traced to the interaction between opportunistic individual behavior and permissive group responses common in moral hazard. PMID:19928367

  14. Bitumen fumes: review of work on the potential risk to workers and the present knowledge on its origin.

    PubMed

    Binet, S; Pfohl-Leszkowicz, A; Brandt, H; Lafontaine, M; Castegnaro, M

    2002-12-01

    Bitumens fumes contain polycyclic aromatic compounds (PAC). There is a possibility of long-term health effects following chronic exposure by inhalation or skin contamination in asphalt road pavers and highway maintenance workers. Epidemiological and experimental studies on this topic are reviewed and the possible causes of cancer discussed with a primary focus on heterocyclic polyaromatic compounds. In 2001, the results of the IARC epidemiological study confirmed an excess of lung cancer despite a lower cancer mortality. In vitro genotoxicity and mechanistic studies demonstrated a mutagenic effect of bitumen fume condensates (BFC) and some data suggested that the polycyclic aromatic hydrocarbons (PAH) analysed were not the major genotoxic compounds in bitumen fume condensates. Other compounds such as nitrogen-, sulfur- and/or oxygen-containing PAH or their alkyl substituted analogues, mutagenic in the Ames mutation assay, may be involved in the genotoxic effect of BFC. After skin painting with BFC, DNA adducts were found in skin, lung and lymphocytes of all the treated animals. Differences in the adduct patterns were also observed, but a more polar adduct was common to the three tissues and not observed in those from rats treated with coal-tar fume condensates (CTFC). Rat inhalation experiments with bitumen fumes confirmed the presence of a DNA-adduct in the lungs with the same Rf as the previous polar adduct. This adduct therefore merits further investigation as a potential biomarker in lymphocyte DNA to follow exposed workers. All the analytical data and the mechanistic data are complementary and suggest the potential role of thiophenes in the genotoxicity of bitumen fumes. Some thiophenes have lower mutagenic activity than their isosteric PAH, whereas others are very potent carcinogens. Generally, the sulfur analogues of PAH (SPAH) in bitumen fumes have a higher concentration than the PAH of similar molecular weight, whereas the SPAH in coal-tar fumes have a

  15. Global Metabolomic Profiling Reveals an Association of Metal Fume Exposure and Plasma Unsaturated Fatty Acids

    PubMed Central

    Chang, Chiung-yu; Fan, Tianteng; Su, Li; Chen, Feng; Christiani, David C.

    2013-01-01

    Background Welding-associated air pollutants negatively affect the health of exposed workers; however, their molecular mechanisms in causing disease remain largely unclear. Few studies have systematically investigated the systemic toxic effects of welding fumes on humans. Objectives To explore the effects of welding fumes on the plasma metabolome, and to identify biomarkers for risk assessment of welding fume exposure. Methods The two-stage, self-controlled exploratory study included 11 boilermakers from a 2011 discovery panel and 8 boilermakers from a 2012 validation panel. Plasma samples were collected pre- and post-welding fume exposure and analyzed by chromatography/mass spectrometry. Results Eicosapentaenoic or docosapentaenoic acid metabolic changes post-welding were significantly associated with particulate (PM2.5) exposure (p<0.05). The combined analysis by linear mixed-effects model showed that exposure was associated with a statistically significant decline in metabolite change of eicosapentaenoic acid [(95% CI) = −0.013(−0.022∼−0.004); p = 0.005], docosapentaenoic acid n3 [(95% CI) = −0.010(−0.018∼−0.002); p = 0.017], and docosapentaenoic acid n6 [(95% CI) = −0.007(−0.013∼−0.001); p = 0.021]. Pathway analysis identified an association of the unsaturated fatty acid pathway with exposure (pStudy−2011 = 0.025; pStudy−2012 = 0.021; pCombined = 0.009). The functional network built by these fatty acids and their interactive genes contained significant enrichment of genes associated with various diseases, including neoplasms, cardiovascular diseases, and lipid metabolism disorders. Conclusions High-dose exposure of metal welding fumes decreases unsaturated fatty acids with an exposure-response relationship. This alteration in fatty acids is a potential biological mediator and biomarker for exposure-related health disorders. PMID:24143234

  16. Welding fumes from stainless steel gas metal arc processes contain multiple manganese chemical species.

    PubMed

    Keane, Michael; Stone, Samuel; Chen, Bean

    2010-05-01

    Fumes from a group of gas metal arc welding (GMAW) processes used on stainless steel were generated using three different metal transfer modes and four different shield gases. The objective was to identify and measure manganese (Mn) species in the fumes, and identify processes that are minimal generators of Mn species. The robotic welding system was operated in short-circuit (SC) mode (Ar/CO2 and He/Ar), axial spray (AXS) mode (Ar/O2 and Ar/CO2), and pulsed axial-spray (PAXS) mode (Ar/O2). The fumes were analyzed for Mn by a sequential extraction process followed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) analysis, and by X-ray diffraction (XRD). Total elemental Mn, iron (Fe), chromium (Cr) and nickel (Ni) were separately measured after aqua regia digestion and ICP-AES analysis. Soluble Mn2+, Fe2+, Fe3+, and Ni2+ in a simple biological buffer (phosphate-buffered saline) were determined at pH 7.2 and 5.0 after 2 h incubation at 37 C by ion chromatography. Results indicate that Mn was present in soluble form, acid-soluble form, and acid-soluble form after reduction by hydroxylamine, which represents soluble Mn0 and Mn2+ compounds, other Mn2+ compounds, and (Mn3+ and Mn4+) compounds, respectively. The dominant fraction was the acid-soluble Mn2+ fraction, but results varied with the process and shield gas. Soluble Mn mass percent in the fume ranged from 0.2 to 0.9%, acid-soluble Mn2+ compounds ranged from 2.6 to 9.3%, and acid plus reducing agent-soluble (Mn3+ and Mn4+) compounds ranged from 0.6 to 5.1%. Total Mn composition ranged from 7 to 15%. XRD results showed fumes had a crystalline content of 90-99% Fe3O4, and showed evidence of multiple Mn oxides, but overlaps and weak signals limited identification. Small amounts of the Mn2+ in the fume (<0.01 to ≈ 1% or <0.1 to ≈ 10 microg ml(-1)) and Ni2+ (<0.01 to ≈ 0.2% or <0.1 to ≈ 2 mg ml(-1)) ions were found in biological buffer media, but amounts were highly dependent on pH and the

  17. Evaluation of factors affecting the containment performance of traditional and nanomaterial fume hoods

    NASA Astrophysics Data System (ADS)

    Dunn, Kevin Holden

    This research was conducted to: 1) evaluate different methods for measuring containment effectiveness of a nanomaterial handling enclosure; 2) to evaluate design and operational factors which may impact containment performance for a traditional constant air volume (CAV) and nano fume using computational fluid dynamics (CFD), and; 3) to assess the impact on the operator body and arm motion on nanoparticle containment of the CAV and nano fume hoods. The research approach to address these objectives starts with an evaluation of the containment effectiveness of a new nanomaterial handling enclosure using tracer gas, nanoparticle and nanoparticle handling methodologies in a real-world laboratory setting. The tracer gas and nanoparticle test results were well-correlated showing hood leakage under the same conditions and at the same sample locations. However, the nanoparticle method was more sensitive than the tracer gas test showing leakage in situations not indicated by the tracer gas tests. These experiments also identified substantial leaks near the sides of the hood sides even when the tracer gas concentration in the manikin breathing zone was not elevated. This result was consistent with new research showing that sampling in the manikin breathing zone may not be adequate to describe containment of fume hood devices. The second phase of this project provides an assessment of the internal flow patterns of a nano fume hood and a traditional CAV chemical fume hood. The impacts of design and operational differences between these hoods are investigated using both experimental measurements and numerical simulations with CFD. An investigation of the airflow patterns inside the hoods showed that large scale recirculation zones develop behind the sash for both hoods. However, the design of the side airfoils of the nano hood resulted in a secondary recirculation pattern along the sides of the hood which impacts interior contaminant dispersion and potential for leakage. The

  18. Design, construction, and characterization of a novel robotic welding fume generator and inhalation exposure system for laboratory animals.

    PubMed

    Antonini, James M; Afshari, Aliakbar A; Stone, Sam; Chen, Bean; Schwegler-Berry, Diane; Fletcher, W Gary; Goldsmith, W Travis; Vandestouwe, Kurt H; McKinney, Walter; Castranova, Vincent; Frazer, David G

    2006-04-01

    Respiratory effects observed in welders have included lung function changes, metal fume fever, bronchitis, and a possible increase in the incidence of lung cancer. Many questions remain unanswered regarding the causality and possible underlying mechanisms associated with the potential toxic effects of welding fume inhalation. The objective of the present study was to construct a completely automated, computer-controlled welding fume generation and inhalation exposure system to simulate real workplace exposures. The system comprised a programmable six-axis robotic welding arm, a water-cooled arc welding torch, and a wire feeder that supplied the wire to the torch at a programmed rate. For the initial studies, gas metal arc welding was performed using a stainless steel electrode. A flexible trunk was attached to the robotic arm of the welder and was used to collect and transport fume from the vicinity of the arc to the animal exposure chamber. Undiluted fume concentrations consistently ranged from 90-150 mg/m(3) in the animal chamber during welding. Temperature and humidity remained constant in the chamber during the welding operation. The welding particles were composed of (from highest to lowest concentration) iron, chromium, manganese, and nickel as measured by inductively coupled plasma atomic emission spectroscopy. Size distribution analysis indicated the mass median aerodynamic diameter of the generated particles to be approximately 0.24 microm with a geometric standard deviation (sigma(g)) of 1.39. As determined by transmission and scanning electron microscopy, the generated aerosols were mostly arranged as chain-like agglomerates of primary particles. Characterization of the laboratory-generated welding aerosol has indicated that particle morphology, size, and chemical composition are comparable to stainless steel welding fume generated in other studies. With the development of this novel system, it will be possible to establish an animal model using

  19. Repetitive Dosing of Fumed Silica Leads to Profibrogenic Effects through Unique Structure-Activity Relationships and Biopersistence in the Lung.

    PubMed

    Sun, Bingbing; Wang, Xiang; Liao, Yu-Pei; Ji, Zhaoxia; Chang, Chong Hyun; Pokhrel, Suman; Ku, Justine; Liu, Xiangsheng; Wang, Meiying; Dunphy, Darren R; Li, Ruibin; Meng, Huan; Mädler, Lutz; Brinker, C Jeffrey; Nel, André E; Xia, Tian

    2016-08-23

    Contrary to the notion that the use of fumed silica in consumer products can "generally (be) regarded as safe" (GRAS), the high surface reactivity of pyrogenic silica differs from other forms of synthetic amorphous silica (SAS), including the capacity to induce membrane damage and acute proinflammatory changes in the murine lung. In addition, the chain-like structure and reactive surface silanols also allow fumed silica to activate the NLRP3 inflammasome, leading to IL-1β production. This pathway is known to be associated with subchronic inflammation and profibrogenic effects in the lung by α-quartz and carbon nanotubes. However, different from the latter materials, bolus dose instillation of 21 mg/kg fumed silica did not induce sustained IL-1β production or subchronic pulmonary effects. In contrast, the NLRP3 inflammasome pathway was continuously activated by repetitive-dose administration of 3 × 7 mg/kg fumed silica, 1 week apart. We also found that while single-dose exposure failed to induce profibrotic effects in the lung, repetitive dosing can trigger increased collagen production, even at 3 × 3 mg/kg. The change between bolus and repetitive dosing was due to a change in lung clearance, with recurrent dosing leading to fumed silica biopersistence, sustained macrophage recruitment, and activation of the NLRP3 pathway. These subchronic proinflammatory effects disappeared when less surface-reactive titanium-doped fumed silica was used for recurrent administration. All considered, these data indicate that while fumed silica may be regarded as safe for some applications, we should reconsider the GRAS label during repetitive or chronic inhalation exposure conditions. PMID:27483033

  20. Transportation of hazardous materials

    SciTech Connect

    Not Available

    1986-07-01

    This report discusses the following: data and information systems for hazardous-materials; containers for hazardous-materials transportation; hazardous-materials transportation regulation; and training for hazardous-materials transportation enforcement and emergency response.

  1. 30 CFR 71.700 - Inhalation hazards; threshold limit values for gases, dust, fumes, mists, and vapors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Information Centers listed in 45 CFR 5.31. Copies of the document may be purchased from American Conference of... containing quartz, and asbestos dust) in excess of, on the basis of a time-weighted average, the...

  2. 30 CFR 71.700 - Inhalation hazards; threshold limit values for gases, dust, fumes, mists, and vapors.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Information Centers listed in 45 CFR 5.31. Copies of the document may be purchased from American Conference of... containing quartz, and asbestos dust) in excess of, on the basis of a time-weighted average, the...

  3. 30 CFR 71.700 - Inhalation hazards; threshold limit values for gases, dust, fumes, mists, and vapors.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Information Centers listed in 45 CFR 5.31. Copies of the document may be purchased from American Conference of... containing quartz, and asbestos dust) in excess of, on the basis of a time-weighted average, the...

  4. 30 CFR 71.700 - Inhalation hazards; threshold limit values for gases, dust, fumes, mists, and vapors.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Information Centers listed in 45 CFR 5.31. Copies of the document may be purchased from American Conference of... containing quartz, and asbestos dust) in excess of, on the basis of a time-weighted average, the...

  5. 30 CFR 71.700 - Inhalation hazards; threshold limit values for gases, dust, fumes, mists, and vapors.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Information Centers listed in 45 CFR 5.31. Copies of the document may be purchased from American Conference of... containing quartz, and asbestos dust) in excess of, on the basis of a time-weighted average, the...

  6. Monolithic stationary phases with incorporated fumed silica nanoparticles. Part II. Polymethacrylate-based monolithic column with "covalently" incorporated modified octadecyl fumed silica nanoparticles for reversed-phase chromatography.

    PubMed

    Aydoğan, Cemil; El Rassi, Ziad

    2016-05-01

    This study is concerned with the incorporation of surface modified fumed silica nanoparticles (FSNPs) into polymethacrylate based monolithic columns for use in reversed phase chromatography (RPC) of small solutes and proteins. First, FSNPs were modified with 3-(trimethoxysilyl)propylmethacrylate (TMSPM) to yield the "hybrid" methacryloyl fumed silica nanoparticle (MFSNP) monomer. The resulting MFSNP was then mixed with glyceryl monomethacrylate (GMM) and ethylene dimethacrylate (EDMA) in a binary porogenic solvent composed of cyclohexanol and dodecanol, and the in situ copolymerization of MFSNP, GMM and EDMA was performed in a stainless steel column of 4.6 mm i.d. The silanol groups of the hybrid monolith thus obtained were grafted with octadecyl ligands by perfusing the hybrid monolithic column with a solution of 4% w/v of dimethyloctadecylchlorosilane (DODCS) in toluene while the column was maintained at 110°C for 6h (in a heated HPLC oven). One of the originalities of this study was to demonstrate MFSNP as a novel derivatized "hybrid monomer" in making RPC monolithic columns with surface bound octadecyl ligands. In this respect, the RPC behavior of the monolithic column with "covalently" incorporated FNSPs having surface grafted octadecyl ligands was evaluated with alkylbenzenes, aniline derivatives and phenolic compounds. The results showed that the hybrid poly(GMA-EDMA-MFSNP) having surface bound octadecyl ligands exhibited hydrophobic interactions under reversed phase elution conditions. Furthermore, six standard proteins were baseline separated on the column using a 10min linear gradient elution at increasing ACN concentration in the mobile phase at a flow rate of 1.0mL/min using a 10 cm×4.6mm i.d. column. The relative standard deviations (RSDs) for the retention times of the tested solutes were lower than 2.1% and 2.4% under isocratic elution and gradient elution conditions, respectively. PMID:27059396

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

    NASA Astrophysics Data System (ADS)

    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%.

  8. Effects of walk-by and sash movement on contaminant leakage of air curtain-isolated fume hood.

    PubMed

    Huang, Rong Fung; Chen, Hong Da; Hung, Chien-Hsiung

    2007-12-01

    The effects of the walk-by motion and sash movement on the containment leakage of an air curtain-isolated fume hood were evaluated and compared with the results of a corresponding conventional fume hood. The air curtain was generated by a narrow planar jet issued from the double-layered sash and a suction slot-flow arranged on the floor of the hood just behind the doorsill. The conventional fume hood used for comparison had the major dimensions identical to the air-curtain hood. SF tracer-gas concentrations were released and measured following the prEN 14175-3:2003 protocol to examine the contaminant leakage levels. Experimental results showed that operating the air-curtain hood at the suction velocity above about 6 m/s and jet velocity about 1 m/s could provide drastically high containment performance when compared with the corresponding conventional fume hood operated at the face velocity of 0.5 m/s. The total air flow required for the air-curtain hood operated at 6 m/s suction velocity and 1 m/s jet velocity was about 20% less than that exhausted by the conventional fume hood. If the suction velocity of the air-curtain hood was increased above 8 m/s, the containment leakage during dynamic motions could be reduced to ignorable level (about 10(3) ppm). PMID:18212476

  9. Manganese accumulation in nail clippings as a biomarker of welding fume exposure and neurotoxicity.

    PubMed

    Sriram, Krishnan; Lin, Gary X; Jefferson, Amy M; Roberts, Jenny R; Andrews, Ronnee N; Kashon, Michael L; Antonini, James M

    2012-01-27

    Occupational exposure to welding fumes (WF) is thought to cause Parkinson's disease (PD)-like neurological dysfunction. An apprehension that WF may accelerate the onset of PD also exists. Identifying reliable biomarkers of exposure and neurotoxicity are therefore critical for biomonitoring and neurological risk characterization of WF exposure. Manganese (Mn) in welding consumables is considered the causative factor for the neurological deficits seen in welders. Hence, we sought to determine if Mn accumulation in blood or nail clippings can be a marker for adverse exposure and neurotoxicity. To model this, rats were exposed by intratracheal instillation to dissolved or suspended fume components collected from gas metal arc-mild steel (GMA-MS) or manual metal arc-hard surfacing (MMA-HS) welding. Trace element analysis revealed selective Mn accumulation in dopaminergic brain areas, striatum (STR) and midbrain (MB), following exposure to the two fumes. This caused dopaminergic abnormality as evidenced by loss of striatal tyrosine hydroxylase (Th; 25-32% decrease) and Parkinson disease (autosomal recessive, early onset) 7 (Park7; 25-46% decrease) proteins. While blood Mn was not detectable, Mn levels in nails strongly correlated with the pattern of Mn accumulation in the striatum (R(2)=0.9386) and midbrain (R(2)=0.9332). Exposure to manganese chloride (MnCl(2)) caused similar Mn accumulation in STR, MB and nail. Our findings suggest that nail Mn has the potential to be a sensitive and reliable biomarker for long-term Mn exposure and associated neurotoxicity. The non-invasive means by which nail clippings can be collected, stored, and transported with relative ease, make it an attractive surrogate for biomonitoring WF exposures in occupational settings. PMID:22085607

  10. Combustion fume structure and dynamics. Period of performance: 8/16/91--2/15/92

    SciTech Connect

    Flagan, R.C.

    1992-12-31

    During pulverized coal combustion, a fume of submicron particles is formed when minerals that have volatilized from the parent coal nucleate to form new particles. The particles thus generated are extremely small, but they grow rapidly due to Brownian coagulation. Much has been learned about these fine particles in experimental studies of the particles formed in coal combustion. Measurements of the variation of chemical composition with particle size clearly demonstrate that the particles smaller than about 0.1 {mu}m in diameter are formed from vapors while larger particles are dominated by residues from the mineral matter in the coal. Theoretical predictions of the evolution of the particle size distribution suggest that the nuclei should produce a sharp peak which may approach 0.1 {mu}m, but they are unlikely to grow much beyond that size in the limited time available in practical combustors. The focus of this research program is on elucidating the fundamental processes that determine the particle size distribution, composition, and agglomerate structures of coal ash fumes. The ultimate objective of this work is the development and validation of a model for the dynamics of combustion fumes, describing both the evolution of the particle size distribution and the particle morphology. The study employs model systems to address the fundamental questions and to provide rigorous validation of the models to be developed. This first phase of the project has been devoted to the development of a detailed experimental strategy that will allow agglomerates with a broad range of fractal dimensions to be studied in the laboratory.

  11. Occupational exposure of air crews to tricresyl phosphate isomers and organophosphate flame retardants after fume events.

    PubMed

    Schindler, Birgit Karin; Weiss, Tobias; Schütze, Andre; Koslitz, Stephan; Broding, Horst Christoph; Bünger, Jürgen; Brüning, Thomas

    2013-04-01

    Aircraft cabin air can possibly be contaminated by tricresyl phosphates (TCP) from jet engine oils during fume events. o-TCP, a known neurotoxin, has been addressed to be an agent that might cause the symptoms reported by cabin crews after fume events. A total of 332 urine samples of pilots and cabin crew members in common passenger airplanes, who reported fume/odour during their last flight, were analysed for three isomers of tricresyl phosphate metabolites as well as dialkyl and diaryl phosphate metabolites of four flame retardants. None of the samples contained o-TCP metabolites above the limit of detection (LOD 0.5 μg/l). Only one sample contained metabolites of m- and p-tricresyl phosphates with levels near the LOD. Median metabolite levels of tributyl phosphate (TBP), tris-(2-chloroethyl) phosphate (TCEP) and triphenyl phosphate (TPP) (DBP 0.28 μg/l; BCEP 0.33 μg/l; DPP 1.1 μg/l) were found to be significantly higher than in unexposed persons from the general population. Median tris-(2-chloropropyl) phosphate (TCPP) metabolite levels were significantly not higher in air crews than in controls. Health complaints reported by air crews can hardly be addressed to o-TCP exposure in cabin air. Elevated metabolite levels for TBP, TCEP and TPP in air crews might occur due to traces of hydraulic fluid in cabin air (TBP, TPP) or due to release of commonly used flame retardants from the highly flame protected environment in the airplane. A slight occupational exposure of air crews to organophosphates was shown. PMID:23179756

  12. Evolution of Welding-Fume Aerosols with Time and Distance from the Source

    PubMed Central

    CENA, L. G.; CHEN, B. T.; KEANE, M. J.

    2016-01-01

    Gas metal arc welding fumes were generated from mild-steel plates and measured near the arc (30 cm), representing first-hand exposure of the welder, and farther away from the source (200 cm), representing second-hand exposure of adjacent workers. Measurements were taken during 1-min welding runs and at subsequent 5-min intervals after the welding process was stopped. Number size distributions were measured in real time. Particle mass distributions were measured using a micro-orifice uniform deposition impactor, and total mass concentrations were measured with polytetrafluorothylene filters. Membrane filters were used for collecting morphology samples for electron microscopy. Average mass concentrations measured near the arc were 45 mg/m3 and 9 mg/m3 at the farther distance. The discrepancy in concentrations at the two distances was attributed to the presence of spatter particles, which were observed only in the morphology samples near the source. As fumes aged over time, mass concentrations at the farther distance decreased by 31% (6.2 mg/m3) after 5 min and an additional 13% (5.4 mg/m3) after 10 min. Particle number and mass distributions during active welding were similar at both distances, indicating similar exposure patterns for welders and adjacent workers. Exceptions were recorded for particles smaller than 50 nm and larger than 3 μm, where concentrations were higher near the arc, indicating higher exposures of welders. These results were confirmed by microscopy analysis. As residence time increased, number concentrations decreased dramatically. In terms of particle number concentrations, second-hand exposures to welding fumes during active welding may be as high as first-hand exposures.

  13. EVALUATION OF LEAKAGE FROM FUME HOODS USING TRACER GAS, TRACER NANOPARTICLES AND NANOPOWDER HANDLING TEST METHODOLOGIES

    PubMed Central

    Dunn, Kevin H.; Tsai, Candace Su-Jung; Woskie, Susan R.; Bennett, James S.; Garcia, Alberto; Ellenbecker, Michael J.

    2015-01-01

    The most commonly reported control used to minimize workplace exposures to nanomaterials is the chemical fume hood. Studies have shown, however, that significant releases of nanoparticles can occur when materials are handled inside fume hoods. This study evaluated the performance of a new commercially available nano fume hood using three different test protocols. Tracer gas, tracer nanoparticle, and nanopowder handling protocols were used to evaluate the hood. A static test procedure using tracer gas (sulfur hexafluoride) and nanoparticles as well as an active test using an operator handling nanoalumina were conducted. A commercially available particle generator was used to produce sodium chloride tracer nanoparticles. Containment effectiveness was evaluated by sampling both in the breathing zone (BZ) of a mannequin and operator as well as across the hood opening. These containment tests were conducted across a range of hood face velocities (60, 80, and 100 feet/minute) and with the room ventilation system turned off and on. For the tracer gas and tracer nanoparticle tests, leakage was much more prominent on the left side of the hood (closest to the room supply air diffuser) although some leakage was noted on the right side and in the BZ sample locations. During the tracer gas and tracer nanoparticle tests, leakage was primarily noted when the room air conditioner was on for both the low and medium hood exhaust air flows. When the room air conditioner was turned off, the static tracer gas tests showed good containment across most test conditions. The tracer gas and nanoparticle test results were well correlated showing hood leakage under the same conditions and at the same sample locations. The impact of a room air conditioner was demonstrated with containment being adversely impacted during the use of room air ventilation. The tracer nanoparticle approach is a simple method requiring minimal setup and instrumentation. However, the method requires the reduction in

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

    PubMed

    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

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

    PubMed

    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

  16. [Methodology and evaluation of exposure to fumes formed during welding of chromium-nickel steel].

    PubMed

    Matczak, W; Chmielnicka, J

    1988-01-01

    Using various methods for determination of welding fumes components and taking into account a simultaneous determination of soluble compounds of chromium III and IV, hygienic evaluation in two working places employing different systems of MMA/SS welding, TIG/SS welding and padding was carried out. As it is indicated by the results, proper hygienic evaluation of working conditions is possible owing to the measurements of individual exposure of workers in the breathing zone, allowing for determination of chromium manganese, nickel, and, while applying low-hydrogen electrodes, also fluorides, in every test. PMID:3226286

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

    PubMed

    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

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

    PubMed

    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 < 0.05) accumulation of atmospheric lead pollution. Edible snails sold along road sides are prone to lead contamination. PMID:18784896

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

    SciTech Connect

    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.

  20. Urinary β2 microglobulin in workers exposed to arc welding fumes.

    PubMed

    Aminian, Omid; Eftekhari, Saeid; Mazaheri, Maria; Sharifian, Seyed Akbar; Sadeghniiat-Haghighi, Khosro

    2011-01-01

    Welding is a process in which two or more metals are attached by the use of heat and, in some cases, pressure. Direct exposure and inhalation of welding fumes causes acute and chronic side effects in humans. Kidney damage is one of these important side effects. β(2) microglobulin is an 11.8 kilodalton protein and levels increase in the case of some inflammatory and viral diseases, or kidney malfunction and autoimmune diseases. In this study measurements of β(2) microglobulin were used as a criterion for assessing effects on the kidneys of workers exposed to welding fumes. The study population were electric arc welders in an industrial plant in Tehran, Iran. For control we selected workers who did not have any exposure to welding fumes. Both groups were selected on the basis of a questionnaire and the consideration of criteria for inclusion and exclusion. In the end 50 cases and 50 controls were chosen. A urine sample was collected from all participants and urinary pH was set to between 6-8 using NaOH (1M). Sample transportation to the laboratory complied with the related standards. The samples were assessed using the ORG 5BM kit. For quantitative assessment of β(2) microglobulin we used the Enzyme-linked Immunosorbent Assay (ELISA) method. The ages of the welders ranged from 21 to 48 years (mean=30.5 ± 5.9 yrs) and of controls from 23 to 56 years (mean=31.8 ± 5.9 yrs). Mean employment duration was 7.86 ± 5.01 years (range 2 to 27 years) for welders. Mean β(2) microglobulin level was 0.10 ± 0.096 μg/ml in welders and 0.11 ± 0.06 in controls. This difference was not statistically significant (P=0.381). In conclusion we don't find that exposure to electric arc welding fumes cause a significant change in urinary β(2) microglobulin compared to the control group. PMID:22131246

  1. Critical evaluation of sequential leaching procedures for the determination of Ni and Mn species in welding fumes.

    PubMed

    Berlinger, B; Náray, M; Sajó, I; Záray, G

    2009-06-01

    In this work, welding fume samples were collected in a welding plant, where corrosion-resistant steel and unalloyed structural steel were welded by gas metal arc welding (GMAW) and manual metal arc welding (MMAW) techniques. The welding fumes were sampled with a fixed-point sampling strategy applying Higgins-Dewell cyclones. The following solutions were used to dissolve the different species of Ni and Mn: ammonium citrate solution [1.7% (m/v) diammonium hydrogen citrate and 0.5% (m/v) citric acid monohydrate] for 'soluble' Ni, 50:1 methanol-bromine solution for metallic Ni, 0.01 M ammonium acetate for soluble Mn, 25% acetic acid for Mn(0) and Mn(2+) and 0.5% hydroxylammonium chloride in 25% acetic acid for Mn(3+) and Mn(4+). 'Insoluble' Ni and Mn contents of the samples were determined after microwave-assisted digestion with the mixture of concentrated (cc). HNO(3), cc. HCl and cc. HF. The sample solutions were analysed by inductively coupled plasma quadrupole mass spectrometry and inductively coupled plasma atomic emission spectrometry. The levels of total Ni and Mn measured in the workplace air were different because of significant differences of the fume generation rates and the distributions of the components in the welding fumes between the welding processes. For quality control of the leaching process, dissolution of the pure stoichiometric Mn and Ni compounds and their mixtures weighing was investigated using the optimized leaching conditions. The results showed the adequacy of the procedure for the pure metal compounds. Based on the extraction procedures, the predominant oxidation states of Ni and Mn proved to be very different depending on the welding techniques and type of the welded steels. The largest amount of Mn in GMAW fumes were found as insoluble Mn (46 and 35% in case of corrosion-resistant steel and unalloyed structural steel, respectively), while MMAW fumes contain mainly soluble Mn, Mn(0) and Mn(2+) (78%) and Mn(3+) and Mn(4+) (54%) in case of

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

    PubMed

    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

  3. Long-term effect of silica fume on the principal properties of low-temperature-cured ceramics

    SciTech Connect

    Persson, B.

    1997-11-01

    This article outlines an experimental and numerical study of the long-term interaction between silica fume and Portland cement in low-temperature-cured ceramics such as concrete subjected to air, water and sealed curing. For this purpose about 2,000 kg of eight qualities of concrete were studied at 4 different ages, each over a period of 90 months. Half of the concretes contained 10% silica fume. Parallel studies of strength, heat of hydration, hydration and internal relative humidity were carried out. New and original results and analyses of the interaction between Portland cement and silica fume related to compressive strength, split tensile strength, hydration and internal relative humidity are presented. The project was carried out between 1989 and 1996.

  4. NASA Hazard Analysis Process

    NASA Technical Reports Server (NTRS)

    Deckert, George

    2010-01-01

    This viewgraph presentation reviews The NASA Hazard Analysis process. The contents include: 1) Significant Incidents and Close Calls in Human Spaceflight; 2) Subsystem Safety Engineering Through the Project Life Cycle; 3) The Risk Informed Design Process; 4) Types of NASA Hazard Analysis; 5) Preliminary Hazard Analysis (PHA); 6) Hazard Analysis Process; 7) Identify Hazardous Conditions; 8) Consider All Interfaces; 9) Work a Preliminary Hazard List; 10) NASA Generic Hazards List; and 11) Final Thoughts

  5. 42 CFR 84.1144 - Silica dust test for dust, fume, and mist respirators; single-use or reusable filters; minimum...

    Code of Federal Regulations, 2010 CFR

    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...

  6. 42 CFR 84.1144 - Silica dust test for dust, fume, and mist respirators; single-use or reusable filters; minimum...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 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...

  7. 42 CFR 84.1144 - Silica dust test for dust, fume, and mist respirators; single-use or reusable filters; minimum...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 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...

  8. 42 CFR 84.1144 - Silica dust test for dust, fume, and mist respirators; single-use or reusable filters; minimum...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 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...

  9. Local exhaust ventilation for the control of welding fumes in the construction industry--a literature review.

    PubMed

    Flynn, Michael R; Susi, Pam

    2012-08-01

    Arc welding is a common unit operation in the construction industry, where frequent changes in location and welding position make it more difficult to control fume exposures than in industries where fixed locations are the norm. Welders may be exposed to a variety of toxic airborne contaminants including manganese (Mn) and hexavalent chromium (CrVI). Local exhaust ventilation (LEV) is a well-known engineering control for welding fumes but has not been adopted widely in the construction industry. This literature review presents data on the performance of a variety of LEV systems for welding fume control from the construction (five references), shipyard (five references), and other industries. The studies indicate that LEV can reduce fume exposures to total particulate, Mn, and CrVI to levels below currently relevant standards. Field studies suggest that 40-50% or more reduction in exposure is possible with portable or fixed LEV systems relative to natural ventilation but that correct positioning of the hood and adequate exhaust flow rates are essential. Successful implementation of extraction guns for gas metal arc welding (GMAW) and flux core arc welding has been demonstrated, indicating that a successful balance between extraction airflow and shielding gas requirements is possible. Work practices are an important part of achieving successful control of fume exposures; in particular, positioning the hood close to the arc, checking exhaust flow rates, and avoiding the plume. Further research is needed on hood size effects for controlling welding fume with portable LEV systems and identifying and overcoming barriers to LEV use in construction. PMID:22459321

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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

  13. Effect of Temperature on the Shear-Thickening Behavior of Fumed Silica Suspensions.

    PubMed

    Warren, Justin; Offenberger, Sean; Toghiani, Hossein; Pittman, Charles U; Lacy, Thomas E; Kundu, Santanu

    2015-08-26

    Shear-thickening fluids (STFs) can be subjected to a significant temperature variation in many applications. Polymeric or oligomeric fluids are commonly used as suspending media for STFs. Because the viscosities of polymeric fluids are strongly temperature-dependent, large temperature changes can profoundly affect the shear-thickening responses. Here, the effect of temperature on the shear-thickening behavior of four low-molecular-weight polymeric glycols/fumed silica suspensions is reported. The dispersed-phase volume fraction, its surface chemistry, and the chemical compositions of the suspending media were varied. These factors influence the viscosity and the interactions between the suspended particles and the suspending media. Fumed silica particles with two different silanol-group surface densities were suspended in the polymeric glycols, where these silanol surface groups formed hydrogen bonds with the suspending media's glycols and internal oxygen atoms. Steady-shear experiments were performed over a temperature range spanning approximately 100 °C. The critical shear rate for the onset of shear thickening decreased with decreasing temperature. The critical shear rates were inversely proportional to the viscosity of the pure suspending media over these same temperature ranges. The response of STFs to varying both the temperature and shear rate investigated here will help to design application-specific STFs. Mitigation of a hypervelocity (6.81 km/s) impact on an aluminum facesheet sandwich composite filled with one of these STFs was demonstrated. PMID:26237541

  14. 1-Hydroxypyrene Levels in Blood Samples of Rats After Exposure to Generator Fumes

    PubMed Central

    Ifegwu, Clinton; Igwo-Ezikpe, Miriam N.; Anyakora, Chimezie; Osuntoki, Akinniyi; Oseni, Kafayat A.; Alao, Eragbae O.

    2013-01-01

    Polynuclear Aromatic Hydrocarbons (PAHs) are a major component of fuel generator fumes. Carcinogenicity of these compounds has long been established. In this study, 37 Swiss albino rats were exposed to generator fumes at varied distances for 8 hours per day for a period of 42 days and the level of 1-hydroxypyrene in their blood was evaluated. This study also tried to correlate the level of blood 1-hyroxypyrene with the distance from the source of pollution. Plasma was collected by centrifuging the whole blood sample followed by complete hydrolysis of the conjugated 1-hydroxypyrene glucuronide to yield the analyte of interest, 1-hydroxypyrene, which was achieved using beta glucuronidase. High performance liquid chromatography (HPLC) with UV detector was used to determine the 1-hydroxypyrene concentrations in the blood samples. The mobile phase was water:methanol (12:88 v/v) isocratic run at the flow rate of 1.2 mL/min with CI8 stationary phase at 250 nm. After 42 days of exposure, blood concentration level of 1-hydroxypyrene ranged from 34 μg/mL to 26.29 μg/mL depending on the distance from source of exposure. The control group had no 1-hydroxypyrene in their blood. After the period of exposure, percentage of death correlated with the distance from the source of exposure. Percentage of death ranged from 56% to zero depending on the proximity to source of pollution. PMID:24179393

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

    PubMed Central

    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

  16. Prospective Study of Metal Fume-Induced Responses of Global Gene Expression Profiling in Whole Blood

    PubMed Central

    Wang, Zhaoxi; Neuberg, Donna; Su, Li; Kim, Jee Young; Chen, Jiu-Chiuan; Christiani, David C.

    2008-01-01

    Metal particulate inhalation causes pulmonary and cardiovascular diseases. Our previous results showed that systemic responses to short-term occupational welding-fume exposure could be assessed by microarray analyses in whole-blood total RNA sampled before and after exposure. To expand our understanding of the duration of particulate-induced gene expression changes, we conducted a study using a similar population 1 yr after the original study and extended our observations in the postexposure period. We recruited 15 individuals with welding fume exposure and 7 nonexposed individuals. Thirteen of the 22 individuals (9 in exposed group and 4 in nonexposed group) had been monitored in the previous study. Whole-blood total RNA was analyzed at 3 time points, including baseline, immediately following exposure (approximately 5 h after baseline), and 24 h after baseline, using cDNA microarray technology. We replicated the patterns of Gene Ontology (GO) terms associated with response to stimulus, cell death, phosphorus metabolism, localization, and regulation of biological processes significantly enriched with altered genes in the nonsmoking exposed group. Most of the identified genes had opposite expression changes between the exposure and postexposure periods in nonsmoking welders. In addition, we found dose-dependent patterns that were affected by smoking status. In conclusion, short-term occupational exposure to metal particulates causes systemic responses in the peripheral blood. Furthermore, the acute particulate-induced effects on gene expression profiling were transient in nonsmoking welders, with most effects diminishing within 19 h following exposure. PMID:18951227

  17. Effects of boundary-layer separation controllers on a desktop fume hood.

    PubMed

    Huang, Rong Fung; Chen, Jia-Kun; Hsu, Ching Min; Hung, Shuo-Fu

    2016-10-01

    A desktop fume hood installed with an innovative design of flow boundary-layer separation controllers on the leading edges of the side plates, work surface, and corners was developed and characterized for its flow and containment leakage characteristics. The geometric features of the developed desktop fume hood included a rearward offset suction slot, two side plates, two side-plate boundary-layer separation controllers on the leading edges of the side plates, a slanted surface on the leading edge of the work surface, and two small triangular plates on the upper left and right corners of the hood face. The flow characteristics were examined using the laser-assisted smoke flow visualization technique. The containment leakages were measured by the tracer gas (sulphur hexafluoride) detection method on the hood face plane with a mannequin installed in front of the hood. The results of flow visualization showed that the smoke dispersions induced by the boundary-layer separations on the leading edges of the side plates and work surface, as well as the three-dimensional complex flows on the upper-left and -right corners of the hood face, were effectively alleviated by the boundary-layer separation controllers. The results of the tracer gas detection method with a mannequin standing in front of the hood showed that the leakage levels were negligibly small (≤0.003 ppm) at low face velocities (≥0.19 m/s). PMID:27104797

  18. Correlation between airflow patterns and performance of a laboratory fume hood.

    PubMed

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

    2006-12-01

    To understand the physical mechanisms of the contaminant dispersion and containment leakage during the ventilation process through a laboratory fume hood, the complicated three-dimensional flow patterns and the real-time tracer gas (SF6) leakage were studied via the laser-assisted flow visualization method and the standard/special gas sampling technique, respectively. Through flow visualization, the large-scale vortex structures and boundary layer separations were found around the side poles and doorsill of the hood. In the near-wake region of the manikin, large recirculation zones and wavy flow structures were also identified. When tracer gas concentration measurements were conducted point-by-point across the sash opening, the areas near the doorsill, the lower parts of the side poles, and the sides of the manikin showed significant contaminant leaks. These areas with high contaminant leaks exactly corresponded to where the flow recirculated or separated. However, when the ANSI/ASHRAE 110-1995 protocol was used to measure the concentration of SF6 at the breathing zone of the manikin, no appreciable leakage was detected. It is suggested that a method based on the aerodynamic features and multipoint leakage detections would reflect a more realistic evaluation of overall performance of laboratory fume hood than a single-point sampling method at the manikin's breathing zone. PMID:17133690

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

    PubMed

    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

  20. Health-hazard evaluation report HETA 85-045-1762, American Crystal Sugar Co. , Crookston, Minnesota

    SciTech Connect

    Almaguer, D.; Boiano, J.M.

    1986-12-01

    Employee exposures to airborne contaminants during sugar-beet processing and to welding fumes during facility maintenance were evaluated at a sugar beet mill owned by the American Crystal Sugar Company (ACSCO), in response to a request from ACSCO's management and the American Federation of Grain Millers International Union. During beet processing, personal breathing-zone and general air samples were collected and analyzed for several chemicals and total and respirable particulates of various dusts. Welding fumes were analyzed by inductively coupled plasma/atomic emission spectroscopy of personal filter samples. The following exposures were considered excessive by the most-stringent criteria: lime-kiln helper to total particulates; Weibul storage-bin housekeeper to sugar dust; diffuser operator and charger to formaldehyde; welders and cutters to total welding fumes and specific metals, particularly hexavalent chromium and nickel. High-volume air and settled-dust samples contained crystalline silica representing a potential hazard. Recommendations include improved particulate containment and ventilation, use of respirators where appropriate, and formaldehyde replacement.

  1. Health Hazard Evaluations

    MedlinePlus

    ... Products Programs Contact NIOSH HHE Media Health Hazard Evaluations (HHEs) Language: English en Español Recommend on Facebook ... or employers can ask the NIOSH Health Hazard Evaluation (HHE) Program to help learn whether health hazards ...

  2. Action on Hazardous Wastes.

    ERIC Educational Resources Information Center

    EPA Journal, 1979

    1979-01-01

    U.S. EPA is gearing up to investigate about 300 hazardous waste dump sites per year that could pose an imminent health hazard. Prosecutions are expected to result from the priority effort at investigating illegal hazardous waste disposal. (RE)

  3. Engineered nanomaterials: exposures, hazards, and risk prevention

    PubMed Central

    2011-01-01

    Nanotechnology presents the possibility of revolutionizing many aspects of our lives. People in many settings (academic, small and large industrial, and the general public in industrialized nations) are either developing or using engineered nanomaterials (ENMs) or ENM-containing products. However, our understanding of the occupational, health and safety aspects of ENMs is still in its formative stage. A survey of the literature indicates the available information is incomplete, many of the early findings have not been independently verified, and some may have been over-interpreted. This review describes ENMs briefly, their application, the ENM workforce, the major routes of human exposure, some examples of uptake and adverse effects, what little has been reported on occupational exposure assessment, and approaches to minimize exposure and health hazards. These latter approaches include engineering controls such as fume hoods and personal protective equipment. Results showing the effectiveness - or lack thereof - of some of these controls are also included. This review is presented in the context of the Risk Assessment/Risk Management framework, as a paradigm to systematically work through issues regarding human health hazards of ENMs. Examples are discussed of current knowledge of nanoscale materials for each component of the Risk Assessment/Risk Management framework. Given the notable lack of information, current recommendations to minimize exposure and hazards are largely based on common sense, knowledge by analogy to ultrafine material toxicity, and general health and safety recommendations. This review may serve as an overview for health and safety personnel, management, and ENM workers to establish and maintain a safe work environment. Small start-up companies and research institutions with limited personnel or expertise in nanotechnology health and safety issues may find this review particularly useful. PMID:21418643

  4. The use of a task-based exposure assessment model (T-BEAM) for assessment of metal fume exposures during welding and thermal cutting.

    PubMed

    Susi, P; Goldberg, M; Barnes, P; Stafford, E

    2000-01-01

    work sites can be used to characterize exposures among sampled trades. Comparison of results to American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit values (TLVs) demonstrate a significant health hazard among sampled trades posed by welding and thermal cutting fume, manganese, nickel, and chromium VI. Direct estimates of the probability of exceeding the ACGIH TLV for respirable particulate suggests that boilermakers (100%) and ironworkers (71%) are at greatest risk. Other task variables evaluated with respect to exposure include task, whether work was performed indoors or outdoors, intermittency of work, and use of ventilation. Use of local or mechanical ventilation reduced mean exposures to fumes significantly. PMID:10660986

  5. Two-dimensional time-dependent modelling of fume formation in a pulsed gas metal arc welding process

    NASA Astrophysics Data System (ADS)

    Boselli, M.; Colombo, V.; Ghedini, E.; Gherardi, M.; Sanibondi, P.

    2013-06-01

    Fume formation in a pulsed gas metal arc welding (GMAW) process is investigated by coupling a time-dependent axi-symmetric two-dimensional model, which takes into account both droplet detachment and production of metal vapour, with a model for fume formation and transport based on the method of moments for the solution of the aerosol general dynamic equation. We report simulative results of a pulsed process (peak current = 350 A, background current 30 A, period = 9 ms) for a 1 mm diameter iron wire, with Ar shielding gas. Results showed that metal vapour production occurs mainly at the wire tip, whereas fume formation is concentrated in the fringes of the arc in the spatial region close to the workpiece, where metal vapours are transported by convection. The proposed modelling approach allows time-dependent tracking of fumes also in plasma processes where temperature-time variations occur faster than nanoparticle transport from the nucleation region to the surrounding atmosphere, as is the case for most pulsed GMAW processes.

  6. DripFume: A Visual Basic Program For Simulating Distribution And Atmospheric Volatilization Of Soil Fumigants Applied Through Drip Irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A Windows-based graphical user interface program (DripFume) was developed in MS Visual Basic (VB) to utilize a two-dimensional multi-phase finite element pesticide transport model to simulate distribution and emission of volatile fumigant chemicals when applied through drip irrigation or shank injec...

  7. Obstructive Pulmonary Function Impairment among Korean Male Workers Exposed to Organic Solvents, Iron Oxide Dust, and Welding Fumes

    PubMed Central

    RYU, Ji Young; LEE, Sang-Yoon; KIM, Dae Hwan

    2013-01-01

    We evaluated spirometric obstructive pulmonary function impairment among workers who were occupationally exposed to organic solvents, iron oxide dust, or welding fumes. Data were collected from records of periodic health examinations of workers. In total, 448 Korean male workers were enrolled and classified into three exposure groups: exposure to organic solvents, iron oxide dust, or welding fumes. Logistic regression analysis was performed to evaluate the association between occupational exposure and pulmonary function. Compared to exposure to organic solvents, exposure to iron oxide dust was significantly associated with obstructive pulmonary function impairment (odds ratio [OR], 9.61; 95% confidence interval [CI], 2.20–41.97). The group exposed to welding fumes did not show a significantly higher OR compare to those exposed to organic solvents (OR, 2.83; 95% CI, 0.74–10.8). These results suggest that exposure to iron oxide dust has a greater association with obstructive pulmonary function impairment than exposure to organic solvents or welding fumes. PMID:24131874

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

    PubMed Central

    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

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

    PubMed

    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

  10. 42 CFR 84.1151 - DOP filter test; respirators designed as respiratory protection against dusts, fumes, and mists...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false DOP filter test; respirators designed as respiratory protection against dusts, fumes, and mists having an air contamination level less than 0.05... contamination level less than 0.05 milligram per cubic meter and against radionuclides; minimum requirements....

  11. 42 CFR 84.1152 - Silica dust loading test; respirators designed as protection against dusts, fumes, and mists...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 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... air contamination level less than 0.05 milligram per cubic meter and against radionuclides;...

  12. 42 CFR 84.1151 - DOP filter test; respirators designed as respiratory protection against dusts, fumes, and mists...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false DOP filter test; respirators designed as respiratory protection against dusts, fumes, and mists having an air contamination level less than 0.05... contamination level less than 0.05 milligram per cubic meter and against radionuclides; minimum requirements....

  13. 42 CFR 84.1152 - Silica dust loading test; respirators designed as protection against dusts, fumes, and mists...

    Code of Federal Regulations, 2010 CFR

    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... air contamination level less than 0.05 milligram per cubic meter and against radionuclides;...

  14. MAGNETIC FIELD INFLUENCE ON NGF-STIMULATED NEURITE OUTGROWTH IN PC-12 CELLS: EFFECT OF PAINT FUMES

    EPA Science Inventory

    MAGNETIC FIELD INFLUENCE ON NGF-STIMULATED NEURITE OUTGROWTH IN PC-12 CELLS: EFFECT OF PAINT FUMES. C. F. Blackman1, D. E. House2*, S. G. Benane3*, A. Ubeda4, M.A. TrilIo4. 1 National Health and Environmental Effects Research Laboratory, EPA,
    Research Triangle Park, North Caro...

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

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Dust, fume, mist, and smoke tests; canister bench tests; gas masks canisters containing filters; minimum requirements. 84.1153 Section 84.1153 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL...

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

    PubMed

    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

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

    PubMed

    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

  18. 42 CFR 84.1151 - DOP filter test; respirators designed as respiratory protection against dusts, fumes, and mists...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false DOP filter test; respirators designed as respiratory protection against dusts, fumes, and mists having an air contamination level less than 0.05... contamination level less than 0.05 milligram per cubic meter and against radionuclides; minimum requirements....

  19. 42 CFR 84.1151 - DOP filter test; respirators designed as respiratory protection against dusts, fumes, and mists...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false DOP filter test; respirators designed as respiratory protection against dusts, fumes, and mists having an air contamination level less than 0.05... contamination level less than 0.05 milligram per cubic meter and against radionuclides; minimum requirements....

  20. 42 CFR 84.1152 - Silica dust loading test; respirators designed as protection against dusts, fumes, and mists...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 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... air contamination level less than 0.05 milligram per cubic meter and against radionuclides;...

  1. 42 CFR 84.1151 - DOP filter test; respirators designed as respiratory protection against dusts, fumes, and mists...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false DOP filter test; respirators designed as respiratory protection against dusts, fumes, and mists having an air contamination level less than 0.05... contamination level less than 0.05 milligram per cubic meter and against radionuclides; minimum requirements....

  2. Airborne nanoparticle exposures while using constant-flow, constant-velocity, and air-curtain-isolated fume hoods.

    PubMed

    Tsai, Su-Jung Candace; Huang, Rong Fung; Ellenbecker, Michael J

    2010-01-01

    Tsai et al. (Airborne nanoparticle exposures associated with the manual handling of nanoalumina and nanosilver in fume hoods. J Nanopart Res 2009; 11: 147-61) found that the handling of dry nanoalumina and nanosilver inside laboratory fume hoods can cause a significant release of airborne nanoparticles from the hood. Hood design affects the magnitude of release. With traditionally designed fume hoods, the airflow moves horizontally toward the hood cupboard; the turbulent airflow formed in the worker wake region interacts with the vortex in the constant-flow fume hood and this can cause nanoparticles to be carried out with the circulating airflow. Airborne particle concentrations were measured for three hood designs (constant-flow, constant-velocity, and air-curtain hoods) using manual handling of nanoalumina particles. The hood operator's airborne nanoparticle breathing zone exposure was measured over the size range from 5 nm to 20 mum. Experiments showed that the exposure magnitude for a constant-flow hood had high variability. The results for the constant-velocity hood varied by operating conditions, but were usually very low. The performance of the air-curtain hood, a new design with significantly different airflow pattern from traditional hoods, was consistent under all operating conditions and release was barely detected. Fog tests showed more intense turbulent airflow in traditional hoods and that the downward airflow from the double-layered sash to the suction slot of the air-curtain hood did not cause turbulence seen in other hoods. PMID:19933309

  3. Nickel-Refining Fumes Induced DNA Damage and Apoptosis of NIH/3T3 Cells via Oxidative Stress

    PubMed Central

    Wang, Yue; Wang, Sheng-Yuan; Jia, Li; Zhang, Lin; Ba, Jing-Chong; Han, Dan; Yu, Cui-Ping; Wu, Yong-Hui

    2016-01-01

    Although there have been numerous studies examining the toxicity and carcinogenicity of nickel compounds in humans and animals, its molecular mechanisms of action are not fully elucidated. In our research, NIH/3T3 cells were exposed to nickel-refining fumes at the concentrations of 0, 6.25, 12.50, 25, 50 and 100 μg/mL for 24 h. Cell viability, cell apoptosis, reactive oxygen species (ROS) level, lactate dehydrogenase (LDH) assay, the level of glutathione (GSH), activities of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) level were detected. The exposure of NIH/3T3 cells to nickel-refining fumes significantly reduced cell viability and induced cell apoptotic death in a dose-dependent manner. Nickel-refining fumes significantly increased ROS levels and induced DNA damage. Nickel-refining fumes may induce the changes in the state of ROS, which may eventually initiate oxidative stress, DNA damage and apoptosis of NIH/3T3 cells. PMID:27347984

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

    PubMed Central

    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

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

    PubMed

    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

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

    SciTech Connect

    Antonini, James M. Stone, Sam; Roberts, Jenny R.; Chen, Bean; Schwegler-Berry, Diane; Afshari, Aliakbar A.; Frazer, David G.

    2007-09-15

    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/m{sup 3} 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 10{sup 4}Listeria 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 {mu}m. 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

  7. Characterization of the Potential Hazards Associated with Potential RCRA Treatment Noncompliances

    SciTech Connect

    Clark, David Lewis

    2015-08-20

    The purpose of this document is to provide a hazard evaluation of the noncompliances and whether any new actions are required to mitigate potential risk to the worker or the public. In short, we have reviewed the noncompliances and have concluded that the possibility of exothermic reactions leading to radioactive release is not credible, and in one case, inconceivable, stemming from the fact that the majority fraction of the waste is compatible with organic absorbents and neutralizers. It is not expected that the noncompliances would generate or produce uncontrolled flammable fumes, gases, extreme heat, pressure, fire, explosions, or violent reactions.

  8. Determination of total sulfur compounds and benzothiazole in asphalt fume samples by gas chromatography with sulfur chemiluminescence detection.

    PubMed

    Jaycox, L B; Olsen, L D

    2000-09-01

    As part of a collaborative project between the National Institute for Occupational Safety and Health and the Federal Highway Administration to evaluate asphalt pavers' exposures to asphalt fume and their potential health effects, a method was developed for the determination of total sulfur compounds and benzothiazole in asphalt fume samples. Asphalt fume samples were collected from asphalt mixtures with and without the addition of ground-up rubber tires. The asphalt fume samples were collected with sampling trains that consisted of a Teflon membrane filter and an XAD-2 adsorbent tube. Filter and sampling tube media were extracted with hexane and subsequently analyzed by gas chromatography with a sulfur chemiluminescence detector. Separation was achieved with a 100 percent dimethyl polysiloxane fused silica column. Typical calibration curves had linear correlation coefficients of 0.99 or better with a relative standard deviation (RSD) of 5 percent. Benzothiazole desorption efficiency (DE) determined using spiked sampling tubes ranged from 96.5 percent at 5.0 micrograms to 89.4 percent at 40 micrograms with RSD values from 0.9 to 4.0 percent. Benzothiazole storage recovery determined using sampling tubes spiked at 20 micrograms and refrigerated for 30 days at 4 degrees C was 89.8 percent when corrected for the DE with an RSD of 1.1 percent. The limit of detection for the method determined using spiked sampling tubes was 0.30 microgram. Quantitation for total sulfur compounds and benzothiazole was against benzothiazole standards in hexane. Because of detector selectivity, sample preparation consisted of a simple hexane extraction even when samples had a high background due to hydrocarbon overload. Detector sensitivity provided quantitation in the sub-microgram region. Because of the sample preparation step and because benzothiazole was determined during the same analysis run, this method is straightforward and analytically efficient. The method has been used to

  9. Non-occupational exposure to paint fumes during pregnancy and risk of congenital anomalies: a cohort study

    PubMed Central

    2012-01-01

    Background Occupational exposure to organic solvents during the 1st trimester of pregnancy has been associated with congenital anomalies. Organic solvents are also used in the home environments in paint products, but no study has investigated the effect of such exposure in a general population. Methods We studied associations between residential exposure to paint fumes during the 1st trimester of pregnancy and predefined subgroups of congenital anomalies, using data from the Danish National Birth Cohort (DNBC). During 2001 and 2003, a total of 20 103 pregnant women, enrolled in the DNBC, were interviewed in the 30th week of gestation about the use of paint in their residence during pregnancy. By the end of first trimester, information about smoking habits, alcohol consumption and occupation were collected. Information on congenital anomalies was obtained from national registers. Associations were examined by estimating odds ratios (OR) using logistic regression. Results In total 1404 women (7%) had been exposed to paint fumes during the 1st trimester of pregnancy and 1086 children were diagnosed with congenital anomalies; 73 children with congenital anomalies had been exposed to paint fumes in utero. Exposure to paint fumes seemed positively associated with congenital anomalies of the nervous system (OR 2.19, 95% confidence interval (CI) 0.76 to 6.32), ear, face and neck (OR 2.15, 95% CI 0.84 to 5.55) and the renal system (OR 2.16, 95% CI 1.02 to 4.58) after adjustment for maternal age, smoking, alcohol consumption and occupational solvent exposure. Congenital anomalies in the remaining subgroups were not associated with the exposure. Conclusions Our results suggest that in the general population, exposure to paint fumes during the 1st trimester of pregnancy may increase the risk of some types of congenital anomalies, but the findings need to be confirmed. PMID:22892023

  10. Pulmonary inflammation and tumor induction in lung tumor susceptible A/J and resistant C57BL/6J mice exposed to welding fume

    PubMed Central

    Zeidler-Erdely, Patti C; Kashon, Michael L; Battelli, Lori A; Young, Shih-Houng; Erdely, Aaron; Roberts, Jenny R; Reynolds, Steven H; Antonini, James M

    2008-01-01

    Background Welding fume has been categorized as "possibly carcinogenic" to humans. Our objectives were to characterize the lung response to carcinogenic and non-carcinogenic metal-containing welding fumes and to determine if these fumes caused increased lung tumorigenicity in A/J mice, a lung tumor susceptible strain. We exposed male A/J and C57BL/6J, a lung tumor resistant strain, by pharyngeal aspiration four times (once every 3 days) to 85 μg of gas metal arc-mild steel (GMA-MS), GMA-stainless steel (SS), or manual metal arc-SS (MMA-SS) fume, or to 25.5 μg soluble hexavalent chromium (S-Cr). Shams were exposed to saline vehicle. Bronchoalveolar lavage (BAL) was done at 2, 7, and 28 days post-exposure. For the lung tumor study, gross tumor counts and histopathological changes were assessed in A/J mice at 48 and 78 weeks post-exposure. Results BAL revealed notable strain-dependent differences with regards to the degree and resolution of the inflammatory response after exposure to the fumes. At 48 weeks, carcinogenic metal-containing GMA-SS fume caused the greatest increase in tumor multiplicity and incidence, but this was not different from sham. By 78 weeks, tumor incidence in the GMA-SS group versus sham approached significance (p = 0.057). A significant increase in perivascular/peribronchial lymphoid infiltrates for the GMA-SS group versus sham and an increased persistence of this fume in lung cells compared to the other welding fumes was found. Conclusion The increased persistence of GMA-SS fume in combination with its metal composition may trigger a chronic, but mild, inflammatory state in the lung possibly enhancing tumorigenesis in this susceptible mouse strain. PMID:18778475

  11. Occupational Hazards of Farming

    PubMed Central

    White, Gill; Cessna, Allan

    1989-01-01

    A number of occupational hazards exist for the farmer and farm worker. They include the hazards of farm machinery, biologic and chemical hazards, and social and environmental stresses. Recognizing of these hazards will help the family physician care for farmers and their families. PMID:21248929

  12. Removal of Fluorides and Chlorides from Zinc Oxide Fumes by Microwave Sulfating Roasting

    NASA Astrophysics Data System (ADS)

    Li, Zhiqiang; Zhang, Libo; Chen, Guo; Peng, Jinhui; Zhou, Liexing; Yin, Shaohua; Liu, Chenhui

    2015-10-01

    Dechlorination and defluorination from zinc oxide dust by microwave sulfating roasting was investigated in this study. According to proposed reactions in the process, detailed experiments were systematically conducted to study the effect of roasting temperature, holding time, air and steam flow rates on the efficiency of the removal of F and Cl. The results show that 92.3% of F and 90.5% of Cl in the fume could be purified when the condition of the roasting temperature of 650 °C, holding time at 60 min, air flow of 300 L/h and steam flow of 8 ml/min was optimized. Our investigation indicates that microwave sulfating roasting could be a promising new way for the dechlorination and defluorination from zinc oxide dust.

  13. The influence of the adsorption of metoclopramide on the surface ionization of fumed silica.

    PubMed

    Buyuktimkin, Tuba; Wurster, Dale Eric

    2015-01-15

    The effect of adsorbed metoclopramide on the surface ionization of fumed silica was studied using potentiometric titration. Adsorption isotherms of metoclopramide to unionized and negatively-charged silica surfaces were generated and compared to the titration data. The adsorption of metoclopramide caused the silica surface charge to become more negative with increasing pH that was independent of ionic strength which suggested that specific adsorbate-surface interactions were occurring. Adsorption studies showed that metoclopramide adsorbs to the unionized silica surface. Ionization caused drug adsorption to increase which was consistent with at least two distinct surface adsorption sites. The ratio of the additional amount of metoclopramide adsorbed to the surface ionized group density determined from the titration curves was approximately unity which showed conclusively that the negatively-charged silanols constitute one of the surface adsorption sites. Potentiometric titration has been shown to be a useful technique for determining the number and types of adsorption sites on the silica surface. PMID:25448578

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

    PubMed

    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

  15. Long-term effects of welding fumes upon respiratory symptoms and pulmonary function.

    PubMed

    Akbarkhanzadeh, F

    1980-05-01

    To evaluate the long-term influence of welding fumes and of cigarette smoke on the function of the bronchopulmonary system a comparative study of spirometric measurements in 209 welders and 109 non-welder controls was performed in a shipyard. The two groups were matched for age, height, smoking habits, residence and social class. Fifty-one percent of the welders had one or more of the respiratory symptoms, while only 26% of the controls had any of the symptoms. Chronic bronchitis was found to be confined to welders who smoked or had smoked. The welders appeared to show significantly increased impairment of lung function and, with advancing years, a deterioration in lung function greater than that of the controls, but, in general, they did not show serious pulmonary insufficiency. PMID:7381614

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

    PubMed

    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

  17. Enhancement of Latent Fingerprints on Fabric Using the Cyanoacrylate Fuming Method Followed by Infrared Spectral Mapping.

    PubMed

    Sonnex, Emily; Almond, Matthew J; Bond, John W

    2016-07-01

    A method has been developed for the visualization of latent fingerprints on fabrics, which is based upon cyanoacrylate (superglue) fuming followed by imaging using an infrared microscope. Results show that imaging on smooth, shiny fabrics such as polyester, silk, nylon, and acetate of different colors and patterns can give an improvement over existing enhancement methods. Results for cotton and polycotton were less successful and it is thought this may be due a combination of the presence of the carbonyl functional group in these fabrics as well as their absorbency to fingerprint sweat. The carbonyl peak (1700 cm(-1) ) provided the optimum spectroscopic feature to map and image a fingerprint. Comparisons between infrared mapping at a specific frequency range and principal component analysis showed that improved imaging was obtained with principal component analysis. PMID:27364294

  18. Enantioselective transesterification by Candida antarctica Lipase B immobilized on fumed silica.

    PubMed

    Kramer, Martin; Cruz, Juan C; Pfromm, Peter H; Rezac, Mary E; Czermak, Peter

    2010-10-01

    Enzymatic catalysis to produce molecules such as perfumes, flavors, and fragrances has the advantage of allowing the products to be labeled "natural" for marketing in the U.S., in addition to the exquisite selectivity and stereoselectivity of enzymes that can be an advantage over chemical catalysis. Enzymatic catalysis in organic solvents is attractive if solubility issues of reactants or products, or thermodynamic issues (water as a product in esterification) complicate or prevent aqueous enzymatic catalysis. Immobilization of the enzyme on a solid support can address the generally poor solubility of enzymes in most solvents. We have recently reported on a novel immobilization method for Candida antarctica Lipase B on fumed silica to improve the enzymatic activity in hexane. This research is extended here to study the enantioselective transesterification of (RS)-1-phenylethanol with vinyl acetate. The maximum catalytic activity for this preparation exceeded the activity (on an equal enzyme amount basis) of the commercial Novozyme 435(®) significantly. The steady-state conversion for (R)-1-phenylethanol was about 75% as confirmed via forward and reverse reaction. The catalytic activity steeply increases with increasing nominal surface coverage of the support until a maximum is reached at a nominal surface coverage of 230%. We hypothesize that the physical state of the enzyme molecules at a low surface coverage is dominated in this case by detrimental strong enzyme-substrate interactions. Enzyme-enzyme interactions may stabilize the active form of the enzyme as surface coverage increases while diffusion limitations reduce the apparent catalytic performance again at multi-layer coverage. The temperature-, solvent-, and long-term stability for CALB/fumed silica preparations showed that these preparations can tolerate temperatures up to 70°C, continuous exposure to solvents, and long-term storage. PMID:20670664

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

    PubMed

    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

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

    PubMed Central

    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

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

    PubMed Central

    Li, Huiqi; Hedmer, Maria; Kåredal, Monica; Björk, Jonas; Stockfelt, Leo; Tinnerberg, Håkan; Albin, Maria; Broberg, Karin

    2015-01-01

    Objectives 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. Methods 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. Results 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. Conclusions 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. PMID:26147298

  2. Monolithic stationary phases with incorporated fumed silica nanoparticles. Part I. Polymethacrylate-based monolithic column with incorporated bare fumed silica nanoparticles for hydrophilic interaction liquid chromatography.

    PubMed

    Aydoğan, Cemil; El Rassi, Ziad

    2016-05-01

    Fumed silica nanoparticles (FSNPs), were incorporated for the first time into a polymethacrylate monolithic column containing glyceryl monomethacrylate (GMM) and ethylene dimethacrylate (EDMA) in order to develop a new monolithic column for hydrophilic interaction high performance liquid chromatography (HILIC). When compared to poly(GMM-EDMA) monolithic column without FSNPs, the same monolithic column with incorporated FSNPs yielded important effects on HILIC separations. The effects of monomers and FSNPs content of the polymerization mixture on the performance of the monolithic column were examined in details, and the optimized stationary phase was investigated over a wide range of mobile phase composition with polar acidic, weakly basic and neutral analytes including hydroxy benzoic acids, nucleotides, nucleosides, dimethylformamide, formamide and thiourea. The retention of these analytes was mainly controlled by hydrophilic interactions with the FSNPs and electrostatic repulsion from the negatively charged silica surface in the case of hydroxy benzoic acids and nucleotides. The electrostatic repulsion was minimized by decreasing the pH of the aqueous component of the mobile phase, which in turn enhanced the retention of acidic solutes. Nucleotides were best separated using step gradient elution at decreasing pH as well as ACN concentration in the mobile phase. Improved peak shape and faster analysis of nucleosides were attained by a fast linear gradient elution with a shallow decrease in the ACN content of the ACN-rich mobile phase. The run-to-run and column-to-column reproducibility were satisfactory. The percent relative standard deviations (%RSDs) for the retention times of tested solutes were lower than 2.5% under isocratic conditions and lower than 3.5 under gradient conditions. PMID:27059399

  3. Hazard function theory for nonstationary natural hazards

    NASA Astrophysics Data System (ADS)

    Read, L.; Vogel, R. M.

    2015-12-01

    Studies from the natural hazards literature indicate that many natural processes, including wind speeds, landslides, wildfires, precipitation, streamflow and earthquakes, show evidence of nonstationary behavior such as trends in magnitudes through time. Traditional probabilistic analysis of natural hazards based on partial duration series (PDS) generally assumes stationarity in the magnitudes and arrivals of events, i.e. that the probability of exceedance is constant through time. Given evidence of trends and the consequent expected growth in devastating impacts from natural hazards across the world, new methods are needed to characterize their probabilistic behavior. The field of hazard function analysis (HFA) is ideally suited to this problem because its primary goal is to describe changes in the exceedance probability of an event over time. HFA is widely used in medicine, manufacturing, actuarial statistics, reliability engineering, economics, and elsewhere. HFA provides a rich theory to relate the natural hazard event series (x) with its failure time series (t), enabling computation of corresponding average return periods and reliabilities associated with nonstationary event series. This work investigates the suitability of HFA to characterize nonstationary natural hazards whose PDS magnitudes are assumed to follow the widely applied Poisson-GP model. We derive a 2-parameter Generalized Pareto hazard model and demonstrate how metrics such as reliability and average return period are impacted by nonstationarity and discuss the implications for planning and design. Our theoretical analysis linking hazard event series x, with corresponding failure time series t, should have application to a wide class of natural hazards.

  4. Formation and structure of self-assembled monolayers of N-octadecyltrichlorosilane on fumed and colloidal silicas

    NASA Astrophysics Data System (ADS)

    Wang, Rongwei

    2000-10-01

    The investigation of hydration states of fumed silicas [Aerosil OX50 (OX50) and 380 (A380) with nominal surface areas of 50 and 380 m2/g, respectively] by FTIR spectroscopy and thermogravimetric analysis (TGA) showed that the surface water content was related to the inherent surface properties of the silicas. It was confirmed that OX50 has less affinity to water molecules than A380. It was also clarified that the density of surface silanols varied with storage and pretreatment conditions. In turn, the amount of surface water was affected by the density and distribution of surface silanols. It has been found that the factors that mainly contribute to the formation and organization of octadecyltrichlorosilane (OTS) self-assembled monolayers (SAMs) are the (1) effective surface area of fumed silica; (2) density and distribution of surface silanols; (3) amount and type of surface water. Well-organized OTS SAMs formed on "suprehydrated" fumed and colloidal silicas. Raman spectral data revealed that the octadecyl chains in polyoctadecyl siloxane (POS) had higher conformational and intermolecular order than that on 106-nm "hydrated" silica beads. The latter were identical to the structures observed for OTS SAMs on "suprehydrated" fumed silicas, which is indicative that curvature did not affect the chain packing. The interactions of the head groups and octadecyl chain tails are two determinants that affect the structure of OTS SAMs at high or full coverage. The study of thermal stability of OTS SAMs by Raman spectroscopy indicated that below 150°C the change in the chain conformation in either POS or OTS SAMs on the silicas is reversible. The 200°C thermal treatment caused the permanent conformation change in case of "suprehydrated" A380 sample, which was attributed to both water in the interfacial region and surface curvature that make more free volume available for long alkyl chain reorganization and sequentially further cross-linking occur. Comparison of in-situ 120

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

    PubMed

    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

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

    PubMed Central

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

    2012-01-01

    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

  7. Study on the health hazards of scrap metal cutters.

    PubMed

    Ho, S F; Wong, P H; Kwok, S F

    1989-12-01

    Scrap metal cutters seemed to be left out in most preventive programmes as the workers were mainly contract workers. The health hazards of scrap metal cutting in 54 workers from a foundry and a ship breaking plant were evaluated. Environmental sampling showed lead levels ranging from 0.02 to 0.57 mg/m3 (threshold limit values is 0.15 mg/m3). Exposure to lead came mainly from the paint coat of the metals cut. Metal fume fever was not reported although their main complaints were cough and rhinitis. Skin burns at all stages of healing and residual scars were seen over hands, forearms and thighs. 96% of the cutters had blood lead levels exceeding 40 micrograms/100 ml with 10 workers exceeding 70 micrograms/100 ml. None had clinical evidence of lead poisoning. The study showed that scrap metal cutting is a hazardous industry associated with significant lead exposure. With proper medical supervision, the blood lead levels of this group of workers decreased illustrating the importance of identifying the hazard and implementing appropriate medical surveillance programmes. PMID:2635395

  8. Handling Hazardous Materials.

    ERIC Educational Resources Information Center

    Piper, James; Piverotto, John

    1990-01-01

    Describes a 16-hour course in hazard communication for vocational instructors, which teaches the proper use, storage, and disposal of hazardous materials in the laboratory as well as techniques for teaching safety. (SK)

  9. Household Hazards to Pets

    MedlinePlus

    ... health by becoming aware of the most common health hazards found in many pet-owning households. Hazards in the Kitchen Foods Many foods are perfectly safe for humans, but could be harmful or potentially deadly to ...

  10. Toenail metal concentration as a biomarker of occupational welding fume exposure

    PubMed Central

    Grashow, Rachel; Zhang, Jinming; Fang, Shona C.; Weisskopf, Marc G.; Christiani, David C.; Cavallari, Jennifer M.

    2014-01-01

    In populations exposed to heavy metals, there are few biomarkers that capture intermediate exposure windows. We sought to determine the correlation between toenail metal concentrations and prior 12 month work activity in welders with variable, metal-rich, welding fume exposures. Forty-eight participants, recruited through a local union, provided 69 sets of toenail clippings. Union-supplied and worker verified personal work histories were used to quantify hours welded and respirator use. Toenail samples were digested and analyzed for lead (Pb), manganese (Mn), cadmium (Cd), nickel (Ni) and arsenic (As) using ICP-MS. Spearman correlation coefficients were used to examine the correlation between toenail metal concentrations. Using mixed models to account for multiple participation times, we divided hours welded into three-month intervals and examined how weld hours correlated with log-transformed toenail Pb, Mn, Cd, Ni and As concentrations. Highest concentrations were found for Ni, followed by Mn, Pb and As, and Cd. All of the metals were significantly correlated with one another (rho range=0.28–0.51), with the exception of Ni and As (rho=0.20, p=0.17). Using mixed models adjusted for age, respirator use, smoking status and BMI, we found that Mn was associated with weld hours 7–9 months prior to clipping (p = 0.003), Pb was associated with weld hours 10–12 months prior to clipping (p=0.03) and over the entire year (p=0.04). Cd was associated with weld hours 10–12 months prior to clipping (p=0.05), and also with the previous year’s total hours welded (p=0.02). The association between Ni and weld hours 7–9 months prior to clipping approached significance (p=0.06). Toenail metal concentrations were not associated with the long-term exposure metric, years as a welder. Results suggest Mn, Pb, and Cd may have particular windows of relevant exposure that reflect work activity. In a population with variable exposure, toenails may serve as useful biomarkers for

  11. Platinum-group elements: quantification in collected exhaust fumes and studies of catalyst surfaces.

    PubMed

    Palacios, M A; Gómez, M M; Moldovan, M; Morrison, G; Rauch, S; Mcleod, C; Ma, R; Laserna, J; Lucena, P; Caroli, S; Alimonti, A; Petrucci, F; Bocca, B; Schramel, P; Lustig, S; Zischka, M; Wass, U; Stenbom, B; Luna, M; Saenz, J C; Santamaría, J; Torrens, J M

    2000-07-20

    Automotive catalytic converters, in which Pt, Pd and Rh (platinum-group elements; PGEs) are the active components for eliminating several noxious components from exhaust fumes, have become the main source of environmental urban pollution by PGEs. This work reports on the catalyst morphology through changes in catalyst surface by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) and laser-induced breakdown spectrometry (LIBS) from fresh to aged catalytic converters. The distribution of these elements in the fresh catalysts analysed (Pt-Pd-Rh gasoline catalyst) is not uniform and occurs mainly in a longitudinal direction. This heterogeneity seems to be greater for Pt and Pd. PGEs released by the catalysts, fresh and aged 30,000 km, were studied in parallel. Whole raw exhaust fumes from four catalysts of three different types were also examined. Two of these were gasoline catalysts (Pt-Pd Rh and Pd-Rh) and the other two were diesel catalysts (Pt). Samples were collected following the 91,441 EUDC driving cycle for light-duty vehicle testing. The results show that at 0 km the samples collected first have the highest content of particulate PGEs and although the general tendency is for the release to decrease with increasing number of samples taken, exceptions are frequent. At 30,000 km the released PGEs in gasoline and diesel catalysts decreased significantly. For fresh gasoline catalysts the mean of the total amount released was approximately 100, 250 and 50 ng km(-1) for Pt, Pd and Rh, respectively. In diesel catalysts the Pt release varied in the range 400-800 ng km-1. After ageing the catalysts up to 30,000 km, the gasoline catalysts released amounts of Pt between 6 and 8 ng km(-1), Pd between 12 and 16 ng km(-1) and Rh between 3 and 12 ng km(-1). In diesel catalysts the Pt release varied in the range 108-150 ng km(-1). The soluble portion of PGEs in the HNO3 collector solution represented less than 5% of the total amount for fresh catalysts

  12. Toenail metal concentration as a biomarker of occupational welding fume exposure.

    PubMed

    Grashow, Rachel; Zhang, Jinming; Fang, Shona C; Weisskopf, Marc G; Christiani, David C; Cavallari, Jennifer M

    2014-01-01

    In populations exposed to heavy metals, there are few biomarkers that capture intermediate exposure windows. We sought to determine the correlation between toenail metal concentrations and prior 12-month work activity in welders with variable, metal-rich, welding fume exposures. Forty-eight participants, recruited through a local union, provided 69 sets of toenail clippings. Union-supplied and worker-verified personal work histories were used to quantify hours welded and respirator use. Toenail samples were digested and analyzed for lead (Pb), manganese (Mn), cadmium (Cd), nickel (Ni), and arsenic (As) using ICP-MS. Spearman correlation coefficients were used to examine the correlation between toenail metal concentrations. Using mixed models to account for multiple participation times, we divided hours welded into three-month intervals and examined how weld hours correlated with log-transformed toenail Pb, Mn, Cd, Ni, and As concentrations. Highest concentrations were found for Ni, followed by Mn, Pb and As, and Cd. All the metals were significantly correlated with one another (rho range = 0.28-0.51), with the exception of Ni and As (rho = 0.20, p = 0.17). Using mixed models adjusted for age, respirator use, smoking status, and BMI, we found that Mn was associated with weld hours 7-9 months prior to clipping (p = 0.003), Pb was associated with weld hours 10-12 months prior to clipping (p = 0.03) and over the entire year (p = 0.04). Cd was associated with weld hours 10-12 months prior to clipping (p = 0.05), and also with the previous year's total hours welded (p = 0.02). The association between Ni and weld hours 7-9 months prior to clipping approached significance (p = 0.06). Toenail metal concentrations were not associated with the long-term exposure metric, years as a welder. Results suggest Mn, Pb, and Cd may have particular windows of relevant exposure that reflect work activity. In a population with variable exposure, toenails may serve as useful biomarkers

  13. Numerical investigation of the effects of iron oxidation reactions on the fume formation mechanism in arc welding

    NASA Astrophysics Data System (ADS)

    Sanibondi, Paolo

    2015-09-01

    Fume formation during arc welding has been modelled using a stochastic approach taking into account iron oxidation reactions. The model includes the nucleation and condensation of Fe and FeO vapours, the reaction of gaseous O2 and O on the nanoparticle surface, the coagulation of the nanoparticles including a sintering time as a function of temperature and composition, assuming chemical equilibrium for species in the gaseous phase. Results suggest that fumes generated in gas metal arc welding with oxidizing shielding mixtures are composed of aggregates of primary particles that are nucleated from gas-phase FeO and further oxidized to Fe3O4 and Fe2O3 in the liquid and solid phase, respectively. The composition of the fumes at the end of the formation process depends on the relative initial concentration of Fe and O2 species in the gas mixture and on the diameter of the primary particles that compose the aggregates: as the oxidation reactions are driven by deposition of oxygen on nanoparticle surface, the oxidation of larger particles is slower than that of smaller particles because of their lower surface to volume ratio. Solid-state diffusion is limiting the oxidation process at temperatures lower than 1500 K, inducing the formation of not fully oxidized particles composed of Fe3O4.

  14. Development of UHPC mixtures utilizing natural and industrial waste materials as partial replacements of silica fume and sand.

    PubMed

    Ahmad, Shamsad; Hakeem, Ibrahim; Maslehuddin, Mohammed

    2014-01-01

    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. PMID:25197709

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

    PubMed Central

    2014-01-01

    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. PMID:25197709

  16. Hazard function theory for nonstationary natural hazards

    NASA Astrophysics Data System (ADS)

    Read, Laura K.; Vogel, Richard M.

    2016-04-01

    Impact from natural hazards is a shared global problem that causes tremendous loss of life and property, economic cost, and damage to the environment. Increasingly, many natural processes show evidence of nonstationary behavior including wind speeds, landslides, wildfires, precipitation, streamflow, sea levels, and earthquakes. Traditional probabilistic analysis of natural hazards based on peaks over threshold (POT) generally assumes stationarity in the magnitudes and arrivals of events, i.e., that the probability of exceedance of some critical event is constant through time. Given increasing evidence of trends in natural hazards, new methods are needed to characterize their probabilistic behavior. The well-developed field of hazard function analysis (HFA) is ideally suited to this problem because its primary goal is to describe changes in the exceedance probability of an event over time. HFA is widely used in medicine, manufacturing, actuarial statistics, reliability engineering, economics, and elsewhere. HFA provides a rich theory to relate the natural hazard event series (X) with its failure time series (T), enabling computation of corresponding average return periods, risk, and reliabilities associated with nonstationary event series. This work investigates the suitability of HFA to characterize nonstationary natural hazards whose POT magnitudes are assumed to follow the widely applied generalized Pareto model. We derive the hazard function for this case and demonstrate how metrics such as reliability and average return period are impacted by nonstationarity and discuss the implications for planning and design. Our theoretical analysis linking hazard random variable X with corresponding failure time series T should have application to a wide class of natural hazards with opportunities for future extensions.

  17. Hazard function theory for nonstationary natural hazards

    NASA Astrophysics Data System (ADS)

    Read, L. K.; Vogel, R. M.

    2015-11-01

    Impact from natural hazards is a shared global problem that causes tremendous loss of life and property, economic cost, and damage to the environment. Increasingly, many natural processes show evidence of nonstationary behavior including wind speeds, landslides, wildfires, precipitation, streamflow, sea levels, and earthquakes. Traditional probabilistic analysis of natural hazards based on peaks over threshold (POT) generally assumes stationarity in the magnitudes and arrivals of events, i.e. that the probability of exceedance of some critical event is constant through time. Given increasing evidence of trends in natural hazards, new methods are needed to characterize their probabilistic behavior. The well-developed field of hazard function analysis (HFA) is ideally suited to this problem because its primary goal is to describe changes in the exceedance probability of an event over time. HFA is widely used in medicine, manufacturing, actuarial statistics, reliability engineering, economics, and elsewhere. HFA provides a rich theory to relate the natural hazard event series (X) with its failure time series (T), enabling computation of corresponding average return periods, risk and reliabilities associated with nonstationary event series. This work investigates the suitability of HFA to characterize nonstationary natural hazards whose POT magnitudes are assumed to follow the widely applied Generalized Pareto (GP) model. We derive the hazard function for this case and demonstrate how metrics such as reliability and average return period are impacted by nonstationarity and discuss the implications for planning and design. Our theoretical analysis linking hazard event series X, with corresponding failure time series T, should have application to a wide class of natural hazards with rich opportunities for future extensions.

  18. Hazard function theory for nonstationary natural hazards

    DOE PAGESBeta

    Read, Laura K.; Vogel, Richard M.

    2016-04-11

    Impact from natural hazards is a shared global problem that causes tremendous loss of life and property, economic cost, and damage to the environment. Increasingly, many natural processes show evidence of nonstationary behavior including wind speeds, landslides, wildfires, precipitation, streamflow, sea levels, and earthquakes. Traditional probabilistic analysis of natural hazards based on peaks over threshold (POT) generally assumes stationarity in the magnitudes and arrivals of events, i.e., that the probability of exceedance of some critical event is constant through time. Given increasing evidence of trends in natural hazards, new methods are needed to characterize their probabilistic behavior. The well-developed field ofmore » hazard function analysis (HFA) is ideally suited to this problem because its primary goal is to describe changes in the exceedance probability of an event over time. HFA is widely used in medicine, manufacturing, actuarial statistics, reliability engineering, economics, and elsewhere. HFA provides a rich theory to relate the natural hazard event series (X) with its failure time series (T), enabling computation of corresponding average return periods, risk, and reliabilities associated with nonstationary event series. This work investigates the suitability of HFA to characterize nonstationary natural hazards whose POT magnitudes are assumed to follow the widely applied generalized Pareto model. We derive the hazard function for this case and demonstrate how metrics such as reliability and average return period are impacted by nonstationarity and discuss the implications for planning and design. As a result, our theoretical analysis linking hazard random variable X with corresponding failure time series T should have application to a wide class of natural hazards with opportunities for future extensions.« less

  19. Hazardous Waste Roundup

    ERIC Educational Resources Information Center

    Farenga, Stephen J.; Joyce, Beverly A.; Ness, Daniel

    2004-01-01

    According to the Environmental Protection Agency (EPA), Americans generate approximately 1.6 million tons of hazardous household waste every year. When most people think of hazardous waste, they generally think of materials used in construction, the defense industry, mining, manufacturing, and agriculture. Few people think of hazardous substances…

  20. Automated Hazard Analysis

    Energy Science and Technology Software Center (ESTSC)

    2003-06-26

    The Automated Hazard Analysis (AHA) application is a software tool used to conduct job hazard screening and analysis of tasks to be performed in Savannah River Site facilities. The AHA application provides a systematic approach to the assessment of safety and environmental hazards associated with specific tasks, and the identification of controls regulations, and other requirements needed to perform those tasks safely. AHA is to be integrated into existing Savannah River site work control andmore » job hazard analysis processes. Utilization of AHA will improve the consistency and completeness of hazard screening and analysis, and increase the effectiveness of the work planning process.« less

  1. Hazard Analysis Database Report

    SciTech Connect

    GRAMS, W.H.

    2000-12-28

    The Hazard Analysis Database was developed in conjunction with the hazard analysis activities conducted in accordance with DOE-STD-3009-94, Preparation Guide for U S . Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports, for HNF-SD-WM-SAR-067, Tank Farms Final Safety Analysis Report (FSAR). The FSAR is part of the approved Authorization Basis (AB) for the River Protection Project (RPP). This document describes, identifies, and defines the contents and structure of the Tank Farms FSAR Hazard Analysis Database and documents the configuration control changes made to the database. The Hazard Analysis Database contains the collection of information generated during the initial hazard evaluations and the subsequent hazard and accident analysis activities. The Hazard Analysis Database supports the preparation of Chapters 3 ,4 , and 5 of the Tank Farms FSAR and the Unreviewed Safety Question (USQ) process and consists of two major, interrelated data sets: (1) Hazard Analysis Database: Data from the results of the hazard evaluations, and (2) Hazard Topography Database: Data from the system familiarization and hazard identification.

  2. Preliminary Appraisal of Ferrocene as an Igniting Agent for JP-4 Fuel and Fuming Nitric Acid

    NASA Technical Reports Server (NTRS)

    Miller, RIley O.

    1953-01-01

    A preliminary experimental study was made of the properties of ferrocene as a solute and as a suspension in JP-4 fuel, and of the ignition delays of ferrocene - JP-4 mixture with A.F. specification 14104 white fuming nitric acid (WFNA). The investigation covered concentrations of 4 to 10 percent by weight ferrocene, and a temperature range of -40 to 80 F. The solubility of ferrocene in JP-4 is about 5 percent at room temperature and about 1 percent (extrapolated) at -80 F. The solubility is increased somewhat by increased aromatics content. Undissolved ferrocene particles of 100 mesh and smaller settle rapidly in JP-4. Clear solutions of 4 and 5 percent ferrocene in JP-4 fuels containing 10 and 25 percent by volume aromatics, respectively, do not ignite with WFNA at room temperature. Mixtures containing 10 percent ferrocene (100- mesh and smaller undissolved particles in suspension) ignited with vigorous persistent flames at room temperature, but did not ignite at -38 F. The ignition delays at room temperature, however, were widely varied; the range from 85 milliseconds to over 1 second perhaps reflected differences in degree of sedimentation.

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

    NASA Astrophysics Data System (ADS)

    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.

  4. A Follow-up Study of Men Exposed to Cadmium Oxide Fume

    PubMed Central

    Bonnell, J. A.; Kazantzis, G.; King, E.

    1959-01-01

    The results of a follow-up study of 100 men first examined in 1953 after exposure to cadmium oxide fume are presented and discussed. In 1953 there were 19 cases of chronic cadmium poisoning amongst these men. Twenty-four new cases are now described. The first signs of chronic cadmium poisoning could be seen after a latent interval after exposure had ended. Respiratory function tests showed a greater deterioration in performance with increase in age in the exposed groups compared with the control group. The results in individual cases of clinical and radiological examination and of the respiratory function tests showed a deterioration in the condition of those men with emphysema in the original survey, and took place despite the fact that the majority of the men with chronic cadmium poisoning were not further exposed to cadmium after 1953. Eighteen of the 24 new cases had proteinuria only. The evidence that chronic cadmium poisoning is associated with renal damage is discussed. PMID:13651557

  5. Chronic Obstructive Pulmonary Disease (COPD) and Vapors, Gases, Dusts, or Fumes (VGDF): A Meta-analysis.

    PubMed

    Ryu, Ji Young; Sunwoo, Yu Eun; Lee, Sang-Yoon; Lee, Chae-Kwan; Kim, Jeong-Ho; Lee, Jong-Tae; Kim, Dae-Hwan

    2015-08-01

    To evaluate the association between the risk of chronic obstructive pulmonary disease (COPD) and exposure to vapors, gases, dusts, or fumes (VGDF), we conducted a meta-analysis of epidemiological studies. We searched for studies investigating the relationship between COPD and occupational exposure to VGDF in the adult population. The bibliographic search was conducted in databases (PubMed and Google Scholar). Eleven studies that met predetermined inclusion criteria were included in the meta-analysis. We calculated the pooled odds ratio (OR) with its 95% confidence interval (CI) of COPD for exposure to VGDF using a random-effects model. The presence of publication bias was explored. There was moderate heterogeneity among the included studies (I(2) = 54.3%). In a random-effects model meta-analysis, the pooled OR for exposure to VGDF was 1.43 for COPD (95% CI: 1.19-1.73) compared with no exposure to VGDF. Publication bias was not observed in this study. Our study suggests that exposure to VGDF is associated with a higher risk of COPD. Further prospective cohort studies are needed to confirm this association. PMID:25255043

  6. Sequelae of fume exposure in confined space welding: a neurological and neuropsychological case series.

    PubMed

    Bowler, Rosemarie M; Nakagawa, Sanae; Drezgic, Marija; Roels, Harry A; Park, Robert M; Diamond, Emily; Mergler, Donna; Bouchard, Maryse; Bowler, Russell P; Koller, William

    2007-03-01

    Welding fume contains manganese (Mn) which is known to be bio-available to and neurotoxic for the central nervous system. Although an essential metal, Mn overexposure may cause manganism, a parkinsonian syndrome. The present welder study sought to improve the clinical portrait of manganism and to determine dose-effect relationships. The welders were employed in the construction of the new Bay Bridge (San Francisco) and welded in confined spaces for up to 2 years with minimal protection and poor ventilation. Neurological, neuropsychological, neurophysiological, and pulmonary examinations were given to 49 welders. Clinical cases were selected on the basis of apriori defined criteria pertaining to welding history and neurological/neuropsychological features. Among the 43 eligible welders, 11 cases of manganism were identified presenting with the following symptoms: sleep disturbance, mood changes, bradykinesia, headaches, sexual dysfunction, olfaction loss, muscular rigidity, tremors, hallucinations, slurred speech, postural instability, monotonous voice, and facial masking. Significant associations between outcome variables and cumulative exposure index (CEI) or blood Mn (MnB) were obtained with CEI for variables implicating attention and concentration, working and immediate memory, cognitive flexibility, and verbal learning; and with MnB for executive function, cognitive flexibility, visuo-spatial construction ability, and visual contrast sensitivity. This study strongly suggests that neuropsychological features contribute in a dose-effect related way to the portrait of manganism usually characterized by tremor, loss in balance, diminished cognitive performance, and signs and symptoms of parkinsonism. PMID:17169432

  7. Number size distribution of fine and ultrafine fume particles from various welding processes.

    PubMed

    Brand, Peter; Lenz, Klaus; Reisgen, Uwe; Kraus, Thomas

    2013-04-01

    Studies in the field of environmental epidemiology indicate that for the adverse effect of inhaled particles not only particle mass is crucial but also particle size is. Ultrafine particles with diameters below 100 nm are of special interest since these particles have high surface area to mass ratio and have properties which differ from those of larger particles. In this paper, particle size distributions of various welding and joining techniques were measured close to the welding process using a fast mobility particle sizer (FMPS). It turned out that welding processes with high mass emission rates (manual metal arc welding, metal active gas welding, metal inert gas welding, metal inert gas soldering, and laser welding) show mainly agglomerated particles with diameters above 100 nm and only few particles in the size range below 50 nm (10 to 15%). Welding processes with low mass emission rates (tungsten inert gas welding and resistance spot welding) emit predominantly ultrafine particles with diameters well below 100 nm. This finding can be explained by considerably faster agglomeration processes in welding processes with high mass emission rates. Although mass emission is low for tungsten inert gas welding and resistance spot welding, due to the low particle size of the fume, these processes cannot be labeled as toxicologically irrelevant and should be further investigated. PMID:23028013

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

    PubMed Central

    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 nanoparticles were subsequently analyzed using a TEM/EDS. SNPs were discharged into the air only during the packing process, which was the last manufacturing step in both the manufacturing facilities studied. In the FS packing process, the geometric mean (GM) NC in the personal samples was 57,000 particles/cm3. The geometric mean diameter (GMD) measured by the SMPS was 64 nm. Due to the high-temperature formation process, the particles exhibited a sintering coagulation. In the SS packing process that includes a manual jet mill operation, the GM NC was calculated to be 72,000 particles/cm3 with an assumption of 1,000,000 particles/cm3 when the upper limit is exceeded (5% of total measure). The particles from SS process had a spherical-shaped morphology with GMD measured by SMPS of 94 nm. PMID:24583511

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

    PubMed

    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

  10. The impedance characterization of Carbon Nanotubes - Fumed Silica Poly (vinyl alcohol) Composites

    NASA Astrophysics Data System (ADS)

    Othman, R. N.; Wilkinson, A. N.

    2016-06-01

    Carbon Nanotube (CNT) was grown on the surface of fumed silica via chemical vapor deposition (CVD) method. In this work, silica acted as a site that holds CNT together, which prevents further agglomeration during composite processing. Iron catalyst at different loading (7.5 wt. % up to 25 wt. %) was introduced via impregnation method to synthesize CNT at 1000°C, under methane flow. Floating catalyst method was used where ferrocene (2.5 wt. % and 5 wt. %) was used as starting reactants together with toluene at 760°C. The reaction time was set at 1 hour for both methods. It was later confirmed via SEM images that the floating catalyst method is more suitable to produce a large amount of CNTs. The sample synthesized via floating catalyst method at both 2.5 wt.% and 5 wt. % ferrocene was later used to prepare composites. Composite films of the particles in poly (vinyl alcohol) (PVOH) were cast and their TEM images show that the dispersion is indeed uniform. From impedance measurement, it was found that the particles synthesized via floating catalyst method were found to form an electrically-conductive percolated network with percolation threshold of 1 wt. %, obtained via percolation equation.

  11. Flow and containment characteristics of an air-curtain fume hood operated at high temperatures.

    PubMed

    Chen, Jia-Kun; Huang, Rong Fung; Hsin, Pei-Yi; Hsu, Ching Min; Chen, Chun-Wann

    2012-01-01

    The flow and leakage characteristics of the air-curtain fume hood under high temperature operation (between 100°C and 250°C) were studied. Laser-assisted flow visualization technique was used to reveal the hot plume movements in the cabinet and the critical conditions for the hood-top leakage. The sulfur hexafluoride tracer-gas concentration test method was employed to examine the containment spillages from the sash opening and the hood top. It was found that the primary parameters dominating the behavior of the flow field and hood performance are the sash height and the suction velocity as an air-curtain hood is operated at high temperatures. At large sash height and low suction velocity, the air curtain broke down and accompanied with three-dimensional flow in the cabinet. Since the suction velocity was low and the sash opening was large, the makeup air drawn down from the hood top became insufficient to counter act the rising hot plume. Under this situation, containment leakage from the sash opening and the hood top was observed. At small sash opening and high suction velocity, the air curtain presented robust characteristics and the makeup air flow from the hood top was sufficiently large. Therefore the containment leakages from the sash opening and the hood top were not observed. According to the results of experiments, quantitative operation sash height and suction velocity corresponding to the operation temperatures were suggested. PMID:22293724

  12. Health-hazard evaluation report No. HETA-88-136-1945, Miller Thermal Technologies, Inc. , Appleton, Wisconsin

    SciTech Connect

    Moss, C.E.; Tubbs, R.L.

    1989-01-01

    In response to a management request, a study was made of possible hazardous working conditions at Miller Thermal Technologies, Inc., Appleton, Wisconsin. Thermal arc spraying (TAS) was used at this facility to apply metal and plastic coatings to substrates. The maximum measured levels of actinic, visible, and infrared radiation measured at the thermal spray system were 22 microwatts/square centimeter (microW/sq cm), 16.7 candelas/sq cm, and 170 microW/sq cm, respectively. Octave band and weighted noise measurements indicated values in excess of 101 decibels-A during operation which indicated that exposure could last no more than 1 hour to be in compliance with NIOSH guidelines. Selected metal-fume samples indicated a potential for exposure to hazardous concentrations of nickel, chromium, and iron. The authors conclude that workers were exposed to potentially hazardous optical radiation, excessive noise levels, and concentrations of toxic metal fumes. The authors recommend the use of appropriate eye, respiratory, and hearing protective equipment. Recommendations are included concerning ventilation system improvements and emergency equipment provisions.

  13. The particle size distribution, density, and specific surface area of welding fumes from SMAW and GMAW mild and stainless steel consumables.

    PubMed

    Hewett, P

    1995-02-01

    Particle size distributions were measured for fumes from mild steel (MS) and stainless steel (SS); shielded metal arc welding (SMAW) and gas metal arc welding (GMAW) consumables. Up to six samples of each type of fume were collected in a test chamber using a micro-orifice uniform deposit (cascade) impactor. Bulk samples were collected for bulk fume density and specific surface area analysis. Additional impactor samples were collected using polycarbonate substrates and analyzed for elemental content. The parameters of the underlying mass distributions were estimated using a nonlinear least squares analysis method that fits a smooth curve to the mass fraction distribution histograms of all samples for each type of fume. The mass distributions for all four consumables were unimodal and well described by a lognormal distribution; with the exception of the GMAW-MS and GMAW-SS comparison, they were statistically different. The estimated mass distribution geometric means for the SMAW-MS and SMAW-SS consumables were 0.59 and 0.46 micron aerodynamic equivalent diameter (AED), respectively, and 0.25 micron AED for both the GMAW-MS and GMAW-SS consumables. The bulk fume densities and specific surface areas were similar for the SMAW-MS and SMAW-SS consumables and for the GMAW-MS and GMAW-SS consumables, but differed between SMAW and GMAW. The distribution of metals was similar to the mass distributions. Particle size distributions and physical properties of the fumes were considerably different when categorized by welding method. Within each welding method there was little difference between MS and SS fumes. PMID:7856513

  14. 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

    PubMed Central

    Jara-Ettinger, Ana Cecilia; López-Tavera, Juan Carlos; Zavala-Cerna, María Guadalupe; Torres-Bugarín, Olivia

    2015-01-01

    Background 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. Material and Methods 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. Results 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. Conclusions 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. PMID:26244938

  15. Minimizing hazardous waste

    SciTech Connect

    DeClue, S.C.

    1996-06-01

    Hazardous waste minimization is a broad term often associated with pollution prevention, saving the environment or protecting Mother Earth. Some associate hazardous waste minimization with saving money. Thousands of hazardous materials are used in processes every day, but when these hazardous materials become hazardous wastes, dollars must be spent for disposal. When hazardous waste is reduced, an organization will spend less money on hazardous waste disposal. In 1993, Fort Bragg reduced its hazardous waste generation by over 100,000 pounds and spent nearly $90,000 less on hazardous waste disposal costs than in 1992. Fort Bragg generates a variety of wastes: Vehicle maintenance wastes such as antifreeze, oil, grease and solvents; helicopter maintenance wastes, including solvents, adhesives, lubricants and paints; communication operation wastes such as lithium, magnesium, mercury and nickel-cadmium batteries; chemical defense wastes detection, decontamination, and protective mask filters. The Hazardous Waste Office has the responsibility to properly identify, characterize, classify and dispose of these waste items in accordance with US Environmental Protection Agency (EPA) and US Department of Transportation (DOT) regulations.

  16. Hazard Analysis Database Report

    SciTech Connect

    GAULT, G.W.

    1999-10-13

    The Hazard Analysis Database was developed in conjunction with the hazard analysis activities conducted in accordance with DOE-STD-3009-94, Preparation Guide for US Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports, for the Tank Waste Remediation System (TWRS) Final Safety Analysis Report (FSAR). The FSAR is part of the approved TWRS Authorization Basis (AB). This document describes, identifies, and defines the contents and structure of the TWRS FSAR Hazard Analysis Database and documents the configuration control changes made to the database. The TWRS Hazard Analysis Database contains the collection of information generated during the initial hazard evaluations and the subsequent hazard and accident analysis activities. The database supports the preparation of Chapters 3,4, and 5 of the TWRS FSAR and the USQ process and consists of two major, interrelated data sets: (1) Hazard Evaluation Database--Data from the results of the hazard evaluations; and (2) Hazard Topography Database--Data from the system familiarization and hazard identification.

  17. Migration and Environmental Hazards

    PubMed Central

    Hunter, Lori M.

    2011-01-01

    Losses due to natural hazards (e.g., earthquakes, hurricanes) and technological hazards (e.g., nuclear waste facilities, chemical spills) are both on the rise. One response to hazard-related losses is migration, with this paper offering a review of research examining the association between migration and environmental hazards. Using examples from both developed and developing regional contexts, the overview demonstrates that the association between migration and environmental hazards varies by setting, hazard types, and household characteristics. In many cases, however, results demonstrate that environmental factors play a role in shaping migration decisions, particularly among those most vulnerable. Research also suggests that risk perception acts as a mediating factor. Classic migration theory is reviewed to offer a foundation for examination of these associations. PMID:21886366

  18. Hazards in the theater.

    PubMed

    Rossol, M; Hinkamp, D

    2001-01-01

    The authors offer a survey of the myriad and unique safety and health hazards faced past and present by performers and theatrical workers, from preproduction work, through the show, and during the strike (dismantling). Special emphasis is given to health hazards posed by the many new plastic resin systems and adhesives used in set, prop, and costume construction; the hazards of special-effect fogs, smokes, haze, dusts, and pyrotechnic emissions; and theatrical makeup. PMID:11567920

  19. Evaluation of the Pulmonary Toxicity of a Fume Generated from a Nickel-, Copper-Based Electrode to be Used as a Substitute in Stainless Steel Welding

    PubMed Central

    Antonini, James M; Badding, Melissa A; Meighan, Terence G; Keane, Michael; Leonard, Stephen S; Roberts, Jenny R

    2014-01-01

    Epidemiology has indicated a possible increase in lung cancer among stainless steel welders. Chromium (Cr) is a primary component of stainless steel welding fume. There is an initiative to develop alternative welding consumables [nickel (Ni)- and copper (Cu)-based alloys] that do not contain Cr. No study has been performed to evaluate the toxicity of fumes generated from Ni- and Cu-based consumables. Dose–response and time-course effects on lung toxicity of a Ni- and Cu-based welding fume (Ni–Cu WF) were examined using an in vivo and in vitro bioassay, and compared with two other well-characterized welding fumes. Even though only trace amounts of Cr were present, a persistent increase in lung injury and inflammation was observed for the Ni–Cu WF compared to the other fumes. The difference in response appears to be due to a direct cytotoxic effect by the Ni–Cu WF sample on lung macrophages as opposed to an elevated production of reactive oxygen species (ROS). PMID:25392698

  20. Preparation and Certification of Two New Bulk Welding Fume Reference Materials for Use in Laboratories Undertaking Analysis of Occupational Hygiene Samples

    PubMed Central

    Butler, Owen; Musgrove, Darren; Stacey, Peter

    2014-01-01

    Workers can be exposed to fume, arising from welding activities, which contain toxic metals and metalloids. Occupational hygienists need to assess and ultimately minimize such exposure risks. The monitoring of the concentration of particles in workplace air is one assessment approach whereby fume, from representative welding activities, is sampled onto a filter and returned to a laboratory for analysis. Inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry are generally employed as instrumental techniques of choice for the analysis of such filter samples. An inherent difficulty, however, with inductively coupled plasma-based analytical techniques is that they typically require a sample to be presented for analysis in the form of a solution. The efficiency of the required dissolution step relies heavily upon the skill and experience of the analyst involved. A useful tool in assessing the efficacy of this dissolution step would be the availability and subsequent analysis of welding fume reference materials with stated elemental concentrations and matrices that match as closely as possible the matrix composition of welding fume samples submitted to laboratories for analysis. This article describes work undertaken at the Health and Safety Laboratory to prepare and certify two new bulk welding fume reference materials that can be routinely used by analysts to assess the performance of the digestion procedures they employ in their laboratories. PMID:24499055

  1. Two-zone model application to breathing zone and area welding fume concentration data.

    PubMed

    Boelter, Fred W; Simmons, Catherine E; Berman, Laurel; Scheff, Peter

    2009-05-01

    This study assessed a professional pipefitter/welder performing shielded metal arc welding on carbon steel under field conditions. The resulting breathing zone (near field) and area (far field) welding fume concentration data were applied to the two-zone model for the purpose of determining field-derived personal exposure emission (generation) rates during actual welding work. The study is unique in that one welder was evaluated under high production conditions for 2 days at two different welding locations: a boiler room and a breezeway. Samples were collected and analyzed for total particulate following NIOSH Method 0500 and for select metals following NIOSH Method 7300. Breezeway average personal breathing zone sample total particulate concentrations ranged from 2.89 mg/m(3) to 4.38 mg/m(3), Fe concentrations ranged from 0.53 to 0.63 mg/m(3), and Mn concentrations ranged from 0.10 to 0.12 mg/m(3). The boiler room average personal breathing zone sample total particulate concentrations ranged from 4.73 mg/m(3) to 5.90 mg/m(3), Fe concentrations ranged from 0.48 to 0.85 mg/m(3), and Mn concentrations ranged from 0.06 to 0.16 mg/m(3). Average arc times ranged from 20 to 25% of the total sampling time. Both tracer gas and anemometer techniques were used to estimate ventilation of the boiler room. The steady-state form of the two-zone model was applied to long-term and short-term sample total particulate, Fe, and Mn concentrations obtained during welding in the boiler room and breezeway. The average generation rate in the boiler room was 39.2 mg/min for TP, 6.4 mg/min for Fe, and 1.3 mg/min for Mn. The average generation rate in the breezeway was 40.0 mg/min for TP, 6.6 mg/min for Fe, and 1.2 mg/min for Mn. The field-based generation rates were considerably lower than laboratory-derived published emission rates of between 280 and 650 mg/min for TP. This study emphasizes the need for field-derived welding fume generation rates and showed the personal breathing zone and

  2. Hazardous waste tracking issues

    SciTech Connect

    Marvin, R. )

    1993-08-01

    The concept of cradle-to-grave oversight of hazardous waste was established in 1976 under RCRA. Since then, the multicopy Uniform Hazardous Waste Manifest has been a key component in the federal tracking system. The manifests ensure that generators, transporters and TSDFs maintain documentation of hazardous waste shipments. To a large extent, the tracking system has served its intended purpose; nevertheless, certain shortcomings exist. Anyone involved in shipping hazardous waste should be aware of the system's weaknesses and take appropriate measures to compensate for them.

  3. Inland Flood Hazards

    NASA Astrophysics Data System (ADS)

    Wohl, Ellen E.

    2000-07-01

    A comprehensive, interdisciplinary review of issues related to inland flood hazards, this important work addresses physical controls on flooding, flood processes and effects, and responses to flooding, from the perspectives of human, aquatic, and riparian communities. The contributors, recognized experts in their fields, draw on examples and case studies of inland flood hazards from around the world. The volume is unique in that it addresses how the nonoccurrence of floods, in association with flow regulation and other human manipulation of river systems, may create hazards for aquatic and riparian communities. This book will be a valuable resource for all professionals concerned with inland flood hazards.

  4. Laboratory integrates VAV fume hood controls with central building automation system

    SciTech Connect

    Bard, E.M.

    1995-03-01

    The new Burke Laboratory (Chemistry Building) at Dartmouth College in Hanover, New Hampshire is a four-story, 80,480 gross ft{sup 2} (7,477 m{sup 2}) teaching and research facility that includes organic, advanced organic and physical chemistry teaching labs, as well as synthetic, physical, biochemistry and NMR research labs. The building also includes support space, lounge areas and faculty offices. All laboratory areas required 100% outside air and all fume hoods have a variable air volume exhaust control system with a tracking supply system. The building contains 87 research hoods and 46 teaching hoods. The laboratories require air flows far in excess of cooling load requirements. The mechanical systems serving this building include: (1) Two steam absorption chillers at 565 tons (1989 kW) each. (2) Two multiple cell cooling towers at 825 tons (2,904 kW) each. (3) A central cogeneration plant distributing steam at 20 psi (138 kPa). The plant has two turbines at 2 MW each and one turbine at 3 MW. (4) Four built-up air handling units at 46,000 cfm (21,707 L/s) each. This article describes how extensive communication between Dartmouth College, the design engineers, the construction manager, and the local utility company culminated in the implementation of systems and equipment with optimized efficiency and cost effectiveness for Dartmouth College. The first-cost premium for all of the implemented energy saving features was approximately $850,000. At average rates of 8 cents/kWh and $15.70/Mlb, annual energy savings are estimated to be approximately $355,000. With a rebate of $479,166, the effective payback for Dartmouth College is one year.

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

    SciTech Connect

    Savchenko, D. V.; Shanina, B. D.; Kalabukhova, E. N.; Sitnikov, A. A.; Lysenko, V. S.; Tertykh, V. A.

    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.

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

    NASA Astrophysics Data System (ADS)

    Savchenko, D. V.; Shanina, B. D.; Kalabukhova, E. N.; Sitnikov, A. A.; Lysenko, V. S.; Tertykh, V. A.

    2014-04-01

    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.

  7. A Scanning Transmission Electron Microscopy Method for Determining Manganese Composition in Welding Fume as a Function of Primary Particle Size.

    PubMed

    Richman, Julie D; Livi, Kenneth J T; Geyh, Alison S

    2011-06-01

    Increasing evidence suggests that the physicochemical properties of inhaled nanoparticles influence the resulting toxicokinetics and toxicodynamics. This report presents a method using scanning transmission electron microscopy (STEM) to measure the Mn content throughout the primary particle size distribution of welding fume particle samples collected on filters for application in exposure and health research. Dark field images were collected to assess the primary particle size distribution and energy-dispersive X-ray and electron energy loss spectroscopy were performed for measurement of Mn composition as a function of primary particle size. A manual method incorporating imaging software was used to measure the primary particle diameter and to select an integration region for compositional analysis within primary particles throughout the size range. To explore the variation in the developed metric, the method was applied to 10 gas metal arc welding (GMAW) fume particle samples of mild steel that were collected under a variety of conditions. The range of Mn composition by particle size was -0.10 to 0.19 %/nm, where a positive estimate indicates greater relative abundance of Mn increasing with primary particle size and a negative estimate conversely indicates decreasing Mn content with size. However, the estimate was only statistically significant (p<0.05) in half of the samples (n=5), which all had a positive estimate. In the remaining samples, no significant trend was measured. Our findings indicate that the method is reproducible and that differences in the abundance of Mn by primary particle size among welding fume samples can be detected. PMID:21625364

  8. A Scanning Transmission Electron Microscopy Method for Determining Manganese Composition in Welding Fume as a Function of Primary Particle Size

    PubMed Central

    Richman, Julie D.; Livi, Kenneth J.T.; Geyh, Alison S.

    2011-01-01

    Increasing evidence suggests that the physicochemical properties of inhaled nanoparticles influence the resulting toxicokinetics and toxicodynamics. This report presents a method using scanning transmission electron microscopy (STEM) to measure the Mn content throughout the primary particle size distribution of welding fume particle samples collected on filters for application in exposure and health research. Dark field images were collected to assess the primary particle size distribution and energy-dispersive X-ray and electron energy loss spectroscopy were performed for measurement of Mn composition as a function of primary particle size. A manual method incorporating imaging software was used to measure the primary particle diameter and to select an integration region for compositional analysis within primary particles throughout the size range. To explore the variation in the developed metric, the method was applied to 10 gas metal arc welding (GMAW) fume particle samples of mild steel that were collected under a variety of conditions. The range of Mn composition by particle size was −0.10 to 0.19 %/nm, where a positive estimate indicates greater relative abundance of Mn increasing with primary particle size and a negative estimate conversely indicates decreasing Mn content with size. However, the estimate was only statistically significant (p<0.05) in half of the samples (n=5), which all had a positive estimate. In the remaining samples, no significant trend was measured. Our findings indicate that the method is reproducible and that differences in the abundance of Mn by primary particle size among welding fume samples can be detected. PMID:21625364

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

    PubMed

    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

  10. Exposure to welding fumes is associated with hypomethylation of the F2RL3 gene: a cardiovascular disease marker

    PubMed Central

    Hossain, Mohammad B; Li, Huiqi; Hedmer, Maria; Tinnerberg, Håkan; Albin, Maria; Broberg, Karin

    2015-01-01

    Background Welders are at risk for cardiovascular disease. Recent studies linked tobacco smoke exposure to hypomethylation of the F2RL3 (coagulation factor II (thrombin) receptor-like 3) gene, a marker for cardiovascular disease prognosis and mortality. However, whether welding fumes cause hypomethylation of F2RL3 remains unknown. Methods We investigated 101 welders (median span of working as a welder: 7 years) and 127 unexposed controls (non-welders with no obvious exposure to respirable dust at work), age range 23–60 years, all currently non-smoking, in Sweden. The participants were interviewed about their work history, lifestyle factors and diseases. Personal sampling of respirable dust was performed for the welders. DNA methylation of F2RL3 in blood was assessed by pyrosequencing of four CpG sites, CpG_2 (corresponds to cg03636183) to CpG_5, in F2RL3. Multivariable linear regression analysis was used to assess the association between exposure to welding fumes and F2RL3 methylation. Results Welders had 2.6% lower methylation of CpG_5 than controls (p<0.001). Higher concentrations of measured respirable dust among the welders were associated with hypomethylation of CpG_2, CpG_4 and CpG_5 (β=−0.49 to −1.4, p<0.012); p<0.029 adjusted for age, previous smoking, passive smoking, education, current residence and respirator use. Increasing the number of years working as a welder was associated with hypomethylation of CpG_4 (linear regression analysis, β=−0.11, p=0.039, adjusted for previous smoking). Previous tobacco smokers had 1.5–4.7% (p<0.014) lower methylation of 3 of the 4 CpG sites in F2RL3 (CpG_2, CpG_4 and CpG_5) compared to never-smokers. A non-significant lower risk of cardiovascular disease with more methylation was observed for all CpG sites. Conclusions Welding fumes exposure and previous smoking were associated with F2RL3 hypomethylation. This finding links low-to-moderate exposure to welding fumes to adverse effects on the cardiovascular

  11. A Natural Hazards Workbook.

    ERIC Educational Resources Information Center

    Kohler, Fred

    This paper discusses the development of and provides examples of exercises from a student workbook for a college-level course about natural hazards. The course is offered once a year to undergraduates at Western Illinois University. Students are introduced to 10 hazards (eight meteorological plus earthquakes and volcanoes) through slides, movies,…

  12. Relative Hazard Calculation Methodology

    SciTech Connect

    DL Strenge; MK White; RD Stenner; WB Andrews

    1999-09-07

    The methodology presented in this document was developed to provide a means of calculating the RH ratios to use in developing useful graphic illustrations. The RH equation, as presented in this methodology, is primarily a collection of key factors relevant to understanding the hazards and risks associated with projected risk management activities. The RH equation has the potential for much broader application than generating risk profiles. For example, it can be used to compare one risk management activity with another, instead of just comparing it to a fixed baseline as was done for the risk profiles. If the appropriate source term data are available, it could be used in its non-ratio form to estimate absolute values of the associated hazards. These estimated values of hazard could then be examined to help understand which risk management activities are addressing the higher hazard conditions at a site. Graphics could be generated from these absolute hazard values to compare high-hazard conditions. If the RH equation is used in this manner, care must be taken to specifically define and qualify the estimated absolute hazard values (e.g., identify which factors were considered and which ones tended to drive the hazard estimation).

  13. Customized hazard maps

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Finding out about the historic occurrence of six different types of natural hazards in any region in the United States recently became a little easier.A Project Impact initiative of the Federal Emergency Management Agency (FEMA) and ESRI—a leading provider of Geographic Information System (GIS) software and a Project Impact partner—offers the public customized online hazard maps.

  14. A Windshear Hazard Index

    NASA Technical Reports Server (NTRS)

    Proctor, Fred H.; Hinton, David A.; Bowles, Roland L.

    2000-01-01

    An aircraft exposed to hazardous low-level windshear may suffer a critical loss of airspeed and altitude, thus endangering its ability to remain airborne. In order to characterize this hazard, a nondimensional index was developed based oil aerodynamic principals and understanding of windshear phenomena, 'This paper reviews the development and application of the Bowles F-tactor. which is now used by onboard sensors for the detection of hazardous windshear. It was developed and tested during NASA/I:AA's airborne windshear program and is now required for FAA certification of onboard radar windshear detection systems. Reviewed in this paper are: 1) definition of windshear and description of atmospheric phenomena that may cause hazardous windshear. 2) derivation and discussion of the F-factor. 3) development of the F-factor hazard threshold, 4) its testing during field deployments, and 5) its use in accident reconstructions,

  15. Natural hazards science strategy

    USGS Publications Warehouse

    Holmes, Jr., Robert R.; Jones, Lucile M.; Eidenshink, Jeffery C.; Godt, Jonathan W.; Kirby, Stephen H.; Love, Jeffrey J.; Neal, Christina A.; Plant, Nathaniel G.; Plunkett, Michael L.; Weaver, Craig S.; Wein, Anne; Perry, Suzanne C.

    2012-01-01

    The mission of the U.S. Geological Survey (USGS) in natural hazards is to develop and apply hazard science to help protect the safety, security, and economic well-being of the Nation. The costs and consequences of natural hazards can be enormous, and each year more people and infrastructure are at risk. USGS scientific research - founded on detailed observations and improved understanding of the responsible physical processes - can help to understand and reduce natural hazard risks and to make and effectively communicate reliable statements about hazard characteristics, such as frequency, magnitude, extent, onset, consequences, and where possible, the time of future events. To accomplish its broad hazard mission, the USGS maintains an expert workforce of scientists and technicians in the earth sciences, hydrology, biology, geography, social and behavioral sciences, and other fields, and engages cooperatively with numerous agencies, research institutions, and organizations in the public and private sectors, across the Nation and around the world. The scientific expertise required to accomplish the USGS mission in natural hazards includes a wide range of disciplines that this report refers to, in aggregate, as hazard science. In October 2010, the Natural Hazards Science Strategy Planning Team (H-SSPT) was charged with developing a long-term (10-year) Science Strategy for the USGS mission in natural hazards. This report fulfills that charge, with a document hereinafter referred to as the Strategy, to provide scientific observations, analyses, and research that are critical for the Nation to become more resilient to natural hazards. Science provides the information that decisionmakers need to determine whether risk management activities are worthwhile. Moreover, as the agency with the perspective of geologic time, the USGS is uniquely positioned to extend the collective experience of society to prepare for events outside current memory. The USGS has critical statutory

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

    PubMed

    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

  17. Slow Release of Permanganate from Injectable Fumed Silica Gel: Rheological Properties and Release Dynamics

    NASA Astrophysics Data System (ADS)

    Yang, S.; Zhong, L.; Oostrom, M.; Li, G.

    2014-12-01

    ISCO (In Situ Chemical Oxidation) has been proved to be a useful remediation technology in destroying most prevalent aqueous organic contaminants. For permanganate (MnO4-) in particular, the chemistry of degradative oxidation is well established for cleaning up groundwater containing trichloroethene (TCE) and tetrachloroethene (PCE). However the long-term effectiveness of the application of this oxidant has been questioned due to the observed post remediation rebound of contaminant concentrations. To improve the efficiency of ISCO using MnO4-under specific site conditions, the technology of emplacing slow-releasing permanganate in an aquifer has been studied. We have developed an injectable slow-release permanganate slurry/gel (ISRPG) by mixing KMnO4 with fumed silica in water. Ideally, the slurry/gel forms would release low concentration of MnO4- by diffusion to maintain a desired concentration level of the agent within the chemically active zone. We have investigated the properties and tested the application of this ISRPG in laboratory studies. Rheological study indicated ISRPG has high viscosity and shear thinning property. The viscosity of silica gel could be lowered by mechanical mixing thus making it easy for subsurface injection. Batch tests revealed that MnO4- was diffused from ISRPG and the gel did not disperse but maintained its initial shape. In column experiments we showed that permanganate release covered 6 times more effluent pore volumes when ISRPG was injected compared to MnO4- solution injection. We also observed TCE degradation by released MnO4-, and the remedial performance occurred over a much longer timeframe with ISRPG compared to MnO4- solution injection. In 2-D flow cell tests we demonstrated that water flows around the injected gel, carrying MnO4- diffused out from the gel and forming a downstream oxidant plume, while the gel was stationary. ISRPG slowly released low concentrations of permanganate to maintain a predetermined level of the

  18. Characterization of the morphological properties of welding fume particles by transmission electron microscopy and digital image analysis.

    PubMed

    Farrants, G; Schüler, B; Karlsen, J; Reith, A; Langård, S

    1989-09-01

    The morphological characteristics of welding fume particles have been determined using transmission electron microscopy (TEM) and automatic image analysis (AIA). Two personal samples and one background sample were collected using a new, easy to handle sampling method, during tungsten inert gas (TIG) and manual metal arc (MMA) welding on Inconel in the same shop. The collection method gave samples which were suitable for TEM and AIA. Electron micrographs were taken in a transmission electron microscope and further analyzed using an image analysis unit. Aggregates composed of many individual particles were analyzed both for the parameters of the aggregate and for the parameters of the individual particles by using an algorithm based on a grain boundary reconstruction technique. The morphological parameters allowed the welding fume's particulate matter to be divided into three types - here called small, medium, and large - with a somewhat unclear distinction between medium and large. Medium and large particles occur either as individual particles or as clusters of approximately spherical particles with average diameters of 0.07 and 0.15 microm, respectively. Small particles occur almost exclusively as long chains or lace-like structures of aggregates of particles, often in the range of 5-10 microm. The aggregates have an average projected area of 2.6 x 10-3 microm2 and are composed of several hundred individual particles. PMID:2801515

  19. Chronic exposure to iron oxide, chromium oxide, and nickel oxide fumes of metal dressers in a steelworks

    PubMed Central

    Jones, J. Graham; Warner, C. G.

    1972-01-01

    Graham Jones, J., and Warner, C. G. (1972).Brit. J. industr. Med.,29, 169-177. Chronic exposure to iron oxide, chromium oxide, and nickel oxide fumes of metal dressers in a steelworks. Occupational and medical histories, smoking habits, respiratory symptoms, chest radiographs, and ventilatory capacities were studied in 14 steelworkers employed as deseamers of steel ingots for periods of up to 16 years. The men were exposed for approximately five hours of each working shift to fume concentrations ranging from 1·3 to 294·1 mg/m3 made up mainly of iron oxide with varying proportions of chromium oxide and nickel oxide. Four of the men, with 14 to 16 years' exposure, showed radiological evidence of pneumoconiosis classified as ILO categories 2 or 3. Of these, two had pulmonary function within the normal range and two had measurable loss of function, moderate in one case and mild in the other. Many observers would diagnose these cases as siderosis but the authors consider that this term should be reserved for cases exposed to pure iron compounds. The correct diagnosis is mixed-dust pneumoconiosis and the loss of pulmonary function is caused by the effects of the mixture of metallic oxides. It is probable that inhalation of pure iron oxide does not cause fibrotic pulmonary changes, whereas the inhalation of iron oxide plus certain other substances obviously does. Images PMID:5021996

  20. Cancer incidence among welders: possible effects of exposure to extremely low frequency electromagnetic radiation (ELF) and to welding fumes.

    PubMed Central

    Stern, R M

    1987-01-01

    Epidemiological studies of cancer incidence among welders disclose a pooled total of 146 cases of leukemia observed versus 159.46 expected, a risk ratio of 0.92, and 40 cases of acute leukemia observed versus 43.39 expected, a risk ratio of 0.92. For respiratory tract cancer, the pooled total is 1789 cases observed versus 1290.7 expected, a risk ratio of 1.39. Most electric welders are exposed to extremely low frequency electromagnetic radiation (ELF) (magnetic flux densities of up to 100,000 microT), a suspected leukemogen, and to concentrated metallic aerosols (up to 200 mg/m3), which can contain the putative respiratory tract carcinogens Cr(VI) and Ni. The two exposures are usually coincident, since welding with an electric current produces welding fumes. The observation of an excess risk for respiratory tract cancer strongly suggests significant exposure both to fumes and to ELF. The absence of increased risk for all leukemia or for acute leukemia among ELF-exposed welders does not support the hypothesis that the observed excess risk for leukemia or acute leukemia among workers in the electrical trades is due to their ELF exposure, which on the average is lower than that of welders. PMID:3447902

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

    SciTech Connect

    Ganjian, Eshmaiel . E-mail: E.Ganjian@Coventry.ac.uk; Pouya, Homayoon Sadeghi

    2005-07-01

    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. Mg{sup 2+} 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.

  2. Effects of sash movement and walk-bys on aerodynamics and contaminant leakage of laboratory fume cupboards.

    PubMed

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

    2007-04-01

    In order to speculate the physical mechanisms of contaminant leakage during sash movement and walk-bys through a laboratory fume cupboard, the complicated three-dimensional flow patterns and the real-time tracer gas leakage are studied via the laser-assisted flow visualization method and the standard gas sampling technique, respectively, over a transparent, full scale chemical fume cupboard. Through the flow visualization, the evolution of drastic changes of the flow pattern is demonstrated. The highly turbulent jet-like currents are induced by the unsteady flow motion near the cupboard face. Large-scale turbulent eddies accompanied with the jet-like currents obviously bring large amount of in-cupboard smoke out to the atmosphere. The turbulent mixing extends the size and the strength of the large-scale eddy circulations, and predominantly contributes to the mechanism that causes the severe spread of contaminant leakage in few seconds. The tracer gas tests that are conducted by employing pr-EN 14175:2003 method show consistent containment results with the flow visualization findings. The temporally evolving large-scale turbulent eddies induced by the sash movement and the walk-bys cause substantially high contaminant leakage to the environment and the breathing zone of the operator. PMID:17485863

  3. Elimination of the hazards from hazardous wastes.

    PubMed Central

    Gloyna, E F; Taylor, R D

    1978-01-01

    The "hazard" associated with a waste essentially controls the overall engineering approach to finding suitable alternatives for solving potential disposal problems. It should be recognized that all factors affecting environmental equilibrium must be considered, including product sales, process design, financing, pre- and end-of-pipe treatment, residuals management, and ultimate bioaccumulation of residuals. To meet this challenge, a systems approach to waste treatment and residuals disposal provides a logical approach, but this management concept requires a thorough understanding of the important physical and chemical aspects of the problem, as well as many social implications of the resulting decisions. Thus waste management within a plant necessarily involves process control, pretreatment and end-of-pipe treatment. Further, it follows that residuals management from a disposal point-of-view must ultimately embrace what is called the "multi-barrier concept." In essence, hazard elimination occurs in varying degrees during each phase of a properly engineered system. PMID:738249

  4. Parametric Hazard Function Estimation.

    Energy Science and Technology Software Center (ESTSC)

    1999-09-13

    Version 00 Phaze performs statistical inference calculations on a hazard function (also called a failure rate or intensity function) based on reported failure times of components that are repaired and restored to service. Three parametric models are allowed: the exponential, linear, and Weibull hazard models. The inference includes estimation (maximum likelihood estimators and confidence regions) of the parameters and of the hazard function itself, testing of hypotheses such as increasing failure rate, and checking ofmore » the model assumptions.« less

  5. Space Debris Hazard Evaluation

    NASA Technical Reports Server (NTRS)

    Davison, Elmer H.; Winslow, Paul C., Jr.

    1961-01-01

    The hazard to space vehicles from natural space debris has been explored. A survey of the available information pertinent to this problem is presented. The hope is that this presentation gives a coherent picture of the knowledge to date in terms of the topic covered. The conclusion reached is that a definite hazard exists but that it can only be poorly assessed on the basis of present information. The need for direct measurement of this hazard is obvious, and some of the problems involved in making these direct measurements have been explored.

  6. Health Care Wide Hazards

    MedlinePlus

    ... Employee Downloads Additional Information Latex Allergy Legionnaires' Disease Mercury Needlesticks Noise Other Hazards (Lack of) PPE Slips/ ... Staphylococcus aureus Latex Allergy Legionnaires' Disease Needlesticks Noise Mercury Inappropriate PPE Slips/Trips/Falls Stress Tuberculosis Lack ...

  7. California's potential volcanic hazards

    SciTech Connect

    Jorgenson, P. )

    1989-01-01

    Although volcanic eruptions have occurred infrequently in California during the last few thousand years, the potential danger to life and property from volcanoes in the state is great enough to be of concern, according to a recent U.S. Geological Survey (USGS) publication. The 17-page bulletin, Potential Hazards from Future Volcanic Eruptions in California, gives a brief history of volcanic activity in California during the past 100,000 years, descriptions of the types of volcanoes in the state, the types of potentially hazardous volcanic events that could occur, and hazard-zonation maps and tables depicting six areas of the state where volcanic eruptions might occur. The six areas and brief descriptions of their past volcanic history and potential for future volcanic hazards are briefly summarized here.

  8. Space flight hazards catalog

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The most significant hazards identified on manned space flight programs are listed. This summary is of special value to system safety engineers in developing safety checklists and otherwise tailoring safety tasks to specific systems and subsystems.

  9. Developing hazardous waste programs

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Developing a fully operational hazardous waste regulatory system requires at least 10 to 15 years—even in countries with strong legal and bureaucratic institutions, according to a report on "The Evolution of Hazardous Waste Programs," which was funded by Resources for the Future (RFF) and the World Bank's South Asia Environment Group, and issued on June 4.The report, which compares the experiences of how four developed and four developing countries have created hazardous waste programs, indicates that hazardous waste issues usually do not become a pressing environmental issue until after countries have dealt with more direct threats to public health, such as contaminated drinking water and air pollution. The countries examined include Indonesia, Thailand, Germany, and the United States.

  10. HAZARDOUS WASTE DESTRUCTION

    EPA Science Inventory

    The paper profiles the current status of hazardous waste thermal destruction in the United States, including facilities and wastes typically handled. The results of extensive EPA-sponsored performance tests are presented for incinerators, industrial boilers, and industrial proces...

  11. Barrier Island Hazard Mapping.

    ERIC Educational Resources Information Center

    Pilkey, Orrin H.; Neal, William J.

    1980-01-01

    Describes efforts to evaluate and map the susceptibility of barrier islands to damage from storms, erosion, rising sea levels and other natural phenomena. Presented are criteria for assessing the safety and hazard potential of island developments. (WB)

  12. Automated Standard Hazard Tool

    NASA Technical Reports Server (NTRS)

    Stebler, Shane

    2014-01-01

    The current system used to generate standard hazard reports is considered cumbersome and iterative. This study defines a structure for this system's process in a clear, algorithmic way so that standard hazard reports and basic hazard analysis may be completed using a centralized, web-based computer application. To accomplish this task, a test server is used to host a prototype of the tool during development. The prototype is configured to easily integrate into NASA's current server systems with minimal alteration. Additionally, the tool is easily updated and provides NASA with a system that may grow to accommodate future requirements and possibly, different applications. Results of this project's success are outlined in positive, subjective reviews complete by payload providers and NASA Safety and Mission Assurance personnel. Ideally, this prototype will increase interest in the concept of standard hazard automation and lead to the full-scale production of a user-ready application.

  13. Probabilistic Tsunami Hazard Analysis

    NASA Astrophysics Data System (ADS)

    Thio, H. K.; Ichinose, G. A.; Somerville, P. G.; Polet, J.

    2006-12-01

    The recent tsunami disaster caused by the 2004 Sumatra-Andaman earthquake has focused our attention to the hazard posed by large earthquakes that occur under water, in particular subduction zone earthquakes, and the tsunamis that they generate. Even though these kinds of events are rare, the very large loss of life and material destruction caused by this earthquake warrant a significant effort towards the mitigation of the tsunami hazard. For ground motion hazard, Probabilistic Seismic Hazard Analysis (PSHA) has become a standard practice in the evaluation and mitigation of seismic hazard to populations in particular with respect to structures, infrastructure and lifelines. Its ability to condense the complexities and variability of seismic activity into a manageable set of parameters greatly facilitates the design of effective seismic resistant buildings but also the planning of infrastructure projects. Probabilistic Tsunami Hazard Analysis (PTHA) achieves the same goal for hazards posed by tsunami. There are great advantages of implementing such a method to evaluate the total risk (seismic and tsunami) to coastal communities. The method that we have developed is based on the traditional PSHA and therefore completely consistent with standard seismic practice. Because of the strong dependence of tsunami wave heights on bathymetry, we use a full waveform tsunami waveform computation in lieu of attenuation relations that are common in PSHA. By pre-computing and storing the tsunami waveforms at points along the coast generated for sets of subfaults that comprise larger earthquake faults, we can efficiently synthesize tsunami waveforms for any slip distribution on those faults by summing the individual subfault tsunami waveforms (weighted by their slip). This efficiency make it feasible to use Green's function summation in lieu of attenuation relations to provide very accurate estimates of tsunami height for probabilistic calculations, where one typically computes

  14. K Basin Hazard Analysis

    SciTech Connect

    PECH, S.H.

    2000-08-23

    This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Final Safety Analysis Report. This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report.

  15. K Basins Hazard Analysis

    SciTech Connect

    WEBB, R.H.

    1999-12-29

    This report describes the methodology used in conducting the K Basins Hazard Analysis, which provides the foundation for the K Basins Safety Analysis Report (HNF-SD-WM-SAR-062, Rev.4). This hazard analysis was performed in accordance with guidance provided by DOE-STD-3009-94, Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report.

  16. Geomorphology and natural hazards

    NASA Astrophysics Data System (ADS)

    Gares, Paul A.; Sherman, Douglas J.; Nordstrom, Karl F.

    1994-08-01

    Natural hazards research was initiated in the 1960's by Gilbert White and his students who promulgated a research paradigm that involved assessing risk from a natural event, identifying adjustments to cope with the hazard, determining people's perception of the event, defining the process by which people choose adjustments, and estimating the effects of public policy on the choice process. Studies of the physical system played an important role in early research, but criticismsof the paradigm resulted in a shift to a prominence of social science. Geomorphologists are working to fill gaps in knowledge of the physical aspects of individual hazards, but use of the information by social scientists will only occur if information is presented in a format that is useful to them. One format involves identifying the hazard according to seven physical parameters established by White and his colleagues: magnitude, frequency, duration, areal extent, speed of onset, spatial dispersion, and temporal spacing. Geomorphic hazards are regarded as related to landscape changes that affect human systems. The processes that produce the changes are rarely geomorphic in nature, but are better regarded as atmospheric or hydrologic. An examination of geomorphic hazards in four fields — soil erosion, mass movement, coastal erosion and fluvial erosion — demonstrates that advances in those fields may be evaluated in terms of the seven parameters. Geomorphologists have contributed to hazard research by focusing on the dynamics of the landforms. The prediction of occurence, the determination of spatial and temporal characteristics, the impact of physical characteristics on people's perception, and the impact of physical characteristics on adjustment formulation. Opportunities for geomorphologists to improve our understanding of geomorphic hazards include research into the characteristics of the events particularly with respect to predicting the occurence, and increased evaluation of the

  17. Carbon Structure Hazard Control

    NASA Technical Reports Server (NTRS)

    Yoder, Tommy; Greene, Ben; Porter, Alan

    2015-01-01

    Carbon composite structures are widely used in virtually all advanced technology industries for a multitude of applications. The high strength-to-weight ratio and resistance to aggressive service environments make them highly desirable. Automotive, aerospace, and petroleum industries extensively use, and will continue to use, this enabling technology. As a result of this broad range of use, field and test personnel are increasingly exposed to hazards associated with these structures. No single published document exists to address the hazards and make recommendations for the hazard controls required for the different exposure possibilities from damaged structures including airborne fibers, fly, and dust. The potential for personnel exposure varies depending on the application or manipulation of the structure. The effect of exposure to carbon hazards is not limited to personnel, protection of electronics and mechanical equipment must be considered as well. The various exposure opportunities defined in this document include pre-manufacturing fly and dust, the cured structure, manufacturing/machining, post-event cleanup, and post-event test and/or evaluation. Hazard control is defined as it is applicable or applied for the specific exposure opportunity. The carbon exposure hazard includes fly, dust, fiber (cured/uncured), and matrix vapor/thermal decomposition products. By using the recommendations in this document, a high level of confidence can be assured for the protection of personnel and equipment.

  18. HAZARD ANALYSIS SOFTWARE

    SciTech Connect

    Sommer, S; Tinh Tran, T

    2008-04-08

    Washington Safety Management Solutions, LLC developed web-based software to improve the efficiency and consistency of hazard identification and analysis, control selection and classification, and to standardize analysis reporting at Savannah River Site. In the new nuclear age, information technology provides methods to improve the efficiency of the documented safety analysis development process which includes hazard analysis activities. This software provides a web interface that interacts with a relational database to support analysis, record data, and to ensure reporting consistency. A team of subject matter experts participated in a series of meetings to review the associated processes and procedures for requirements and standard practices. Through these meetings, a set of software requirements were developed and compiled into a requirements traceability matrix from which software could be developed. The software was tested to ensure compliance with the requirements. Training was provided to the hazard analysis leads. Hazard analysis teams using the software have verified its operability. The software has been classified as NQA-1, Level D, as it supports the analysis team but does not perform the analysis. The software can be transported to other sites with alternate risk schemes. The software is being used to support the development of 14 hazard analyses. User responses have been positive with a number of suggestions for improvement which are being incorporated as time permits. The software has enforced a uniform implementation of the site procedures. The software has significantly improved the efficiency and standardization of the hazard analysis process.

  19. Transportation of Hazardous Materials Emergency Preparedness Hazards Assessment

    SciTech Connect

    Blanchard, A.

    2000-02-28

    This report documents the Emergency Preparedness Hazards Assessment (EPHA) for the Transportation of Hazardous Materials (THM) at the Department of Energy (DOE) Savannah River Site (SRS). This hazards assessment is intended to identify and analyze those transportation hazards significant enough to warrant consideration in the SRS Emergency Management Program.

  20. A model for prediction of fume formation rate in gas metal arc welding (GMAW), globular and spray modes, DC electrode positive.

    PubMed

    Dennis, J H; Hewitt, P J; Redding, C A; Workman, A D

    2001-03-01

    Prediction of fume formation rate during metal arc welding and the composition of the fume are of interest to occupational hygienists concerned with risk assessment and to manufacturers of welding consumables. A model for GMAW (DC electrode positive) is described based on the welder determined process parameters (current, wire feed rate and wire composition), on the surface area of molten metal in the arc and on the partial vapour pressures of the component metals of the alloy wire. The model is applicable to globular and spray welding transfer modes but not to dip mode. Metal evaporation from a droplet is evaluated for short time increments and total evaporation obtained by summation over the life of the droplet. The contribution of fume derived from the weld pool and spatter (particles of metal ejected from the arc) is discussed, as are limitations of the model. Calculated droplet temperatures are similar to values determined by other workers. A degree of relationship between predicted and measured fume formation rates is demonstrated but the model does not at this stage provide a reliable predictive tool. PMID:11182424

  1. 42 CFR 84.1144 - Silica dust test for dust, fume, and mist respirators; single-use or reusable filters; minimum...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... respirators; single-use or reusable filters; minimum requirements. 84.1144 Section 84.1144 Public Health... Silica dust test for dust, fume, and mist respirators; single-use or reusable filters; minimum requirements. (a) Three non-powered respirators with single-use filters will be tested for periods of...

  2. Chemical process hazards analysis

    SciTech Connect

    1996-02-01

    The Office of Worker Health and Safety (EH-5) under the Assistant Secretary for the Environment, Safety and Health of the US Department (DOE) has published two handbooks for use by DOE contractors managing facilities and processes covered by the Occupational Safety and Health Administration (OSHA) Rule for Process Safety Management of Highly Hazardous Chemicals (29 CFR 1910.119), herein referred to as the PSM Rule. The PSM Rule contains an integrated set of chemical process safety management elements designed to prevent chemical releases that can lead to catastrophic fires, explosions, or toxic exposures. The purpose of the two handbooks, ``Process Safety Management for Highly Hazardous Chemicals`` and ``Chemical Process Hazards Analysis,`` is to facilitate implementation of the provisions of the PSM Rule within the DOE. The purpose of this handbook ``Chemical Process Hazards Analysis,`` is to facilitate, within the DOE, the performance of chemical process hazards analyses (PrHAs) as required under the PSM Rule. It provides basic information for the performance of PrHAs, and should not be considered a complete resource on PrHA methods. Likewise, to determine if a facility is covered by the PSM rule, the reader should refer to the handbook, ``Process Safety Management for Highly Hazardous Chemicals`` (DOE- HDBK-1101-96). Promulgation of the PSM Rule has heightened the awareness of chemical safety management issues within the DOE. This handbook is intended for use by DOE facilities and processes covered by the PSM rule to facilitate contractor implementation of the PrHA element of the PSM Rule. However, contractors whose facilities and processes not covered by the PSM Rule may also use this handbook as a basis for conducting process hazards analyses as part of their good management practices. This handbook explains the minimum requirements for PrHAs outlined in the PSM Rule. Nowhere have requirements been added beyond what is specifically required by the rule.

  3. Airborne manganese as dust vs. fume determining blood levels in workers at a manganese alloy production plant

    PubMed Central

    Park, Robert M.; Baldwin, Mary; Bouchard, Maryse F.; Mergler, Donna

    2015-01-01

    The appropriate exposure metrics for characterizing manganese (Mn) exposure associated with neurobehavioral effects have not been established. Blood levels of Mn (B-Mn) provide a potentially important intermediate marker of Mn airborne exposures. Using data from a study of a population of silicon- and ferro-manganese alloy production workers employed between 1973 and 1991, B-Mn levels were modeled in relation to prior Mn exposure using detailed work histories and estimated respirable Mn concentrations from air-sampling records. Despite wide variation in exposure levels estimated for individual jobs, duration of employment (exposure) was itself a strong predictor of B-Mn levels and strongest when an 80-day half-life was applied to contributions over time (t = 6.95, 7.44, respectively; p < 10 −5). Partitioning exposure concentrations based on process origin into two categories: (1) “large” respirable particulate (Mn-LRP) derived mainly from mechanically generated dust, and (2) “small” respirable particulate (Mn-SRP) primarily electric furnace condensation fume, revealed that B-Mn levels largely track the small, fume exposures. With a half-life of 65 days applied in a model with cumulative exposure terms for both Mn-LRP (t = −0.16, p = 0.87) and Mn-SRP (t = 6.45, p < 10 −5), the contribution of the large-size fraction contribution was negligible. Constructing metrics based on the square root of SRP exposure concentrations produced a better model fit (t = 7.87 vs. 7.44, R2 = 0.2333 vs. 0.2157). In a model containing both duration (t = 0.79, p = 0.43) and (square root) fume (t = 2.47, p = 0.01) metrics, the duration term was a weak contributor. Furnace-derived, small respirable Mn particulate appears to be the primary contributor to B-Mn levels, with a dose-rate dependence in a population chronically exposed to Mn, with air-concentrations declining in recent years. These observations may reflect the presence of homeostatic control of Mn levels in the blood

  4. Airborne manganese as dust vs. fume determining blood levels in workers at a manganese alloy production plant.

    PubMed

    Park, Robert M; Baldwin, Mary; Bouchard, Maryse F; Mergler, Donna

    2014-12-01

    The appropriate exposure metrics for characterizing manganese (Mn) exposure associated with neurobehavioral effects have not been established. Blood levels of Mn (B-Mn) provide a potentially important intermediate marker of Mn airborne exposures. Using data from a study of a population of silicon- and ferro-manganese alloy production workers employed between 1973 and 1991, B-Mn levels were modeled in relation to prior Mn exposure using detailed work histories and estimated respirable Mn concentrations from air-sampling records. Despite wide variation in exposure levels estimated for individual jobs, duration of employment (exposure) was itself a strong predictor of B-Mn levels and strongest when an 80-day half-life was applied to contributions over time (t=6.95, 7.44, respectively; p<10(-5)). Partitioning exposure concentrations based on process origin into two categories: (1) "large" respirable particulate (Mn-LRP) derived mainly from mechanically generated dust, and (2) "small" respirable particulate (Mn-SRP) primarily electric furnace condensation fume, revealed that B-Mn levels largely track the small, fume exposures. With a half-life of 65 days applied in a model with cumulative exposure terms for both Mn-LRP (t=-0.16, p=0.87) and Mn-SRP (t=6.45, p<10(-5)), the contribution of the large-size fraction contribution was negligible. Constructing metrics based on the square root of SRP exposure concentrations produced a better model fit (t=7.87 vs. 7.44, R(2)=0.2333 vs. 0.2157). In a model containing both duration (t=0.79, p=0.43) and (square root) fume (t=2.47, p=0.01) metrics, the duration term was a weak contributor. Furnace-derived, small respirable Mn particulate appears to be the primary contributor to B-Mn levels, with a dose-rate dependence in a population chronically exposed to Mn, with air-concentrations declining in recent years. These observations may reflect the presence of homeostatic control of Mn levels in the blood and other body tissues and be

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

    NASA Astrophysics Data System (ADS)

    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

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

    PubMed

    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

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

    NASA Astrophysics Data System (ADS)

    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

  8. Respiratory Symptoms and Lung Function Patterns in Workers Exposed to Wood Smoke and Cooking Oil Fumes (Mai Suya) in Nigeria

    PubMed Central

    Adewole, OO; Desalu, OO; Nwogu, KC; Adewole, TO; Erhabor, GE

    2013-01-01

    Background: ‘Mai suya’ is a common job in the most northern Nigeria in which there is significant exposures to wood smoke and oil fumes. The respiratory impact of these dual exposures on workers engaged in this work has not been previously documented, hence this study was carried out. Aim: The aim is to study the prevalence, patterns and respiratory function assessment among this group. Subject and Methods: This is a case controlled study involving mai suya and workers who are not exposed to wood smoke and oil fumes in an occupational setting. All consenting mai suya and matched controls were recruited. Both groups underwent an interviewer administered questionnaire followed by on spot spirometric test measuring forced expiratory volume in one second (FEV1), forced vital capacity (FVC), peak expiratory flow rate (PEFR). Results are presented using descriptive statistics. Chi square was used to test for association between respiratory symptoms and the job categories. Student's t-test was used to compare values of continuous variables. Odd ratios were determined for the risk of respiratory symptoms and exposure to wood smoke and oil fumes. Results: Both groups are similar in their demographic characters except in their smoking status, so current smokers were excluded from further analysis. The test group had significantly increased occurrence of chest tightness: 59% (19/32), nasal congestion: 37% (12/32), cough: 32% (10/32), and wheeze: 12% (4/32) compared with the control group, odds ratio (OR) 3.1, 95% confidence interval CI (0.1-5.8), P value 0.04, OR 1.2,95% CI (1.04-1.8), P value = 0.02, OR 0.9 95% CI (0.9-1.4), P value = 0.3, and OR 1.2,95% CI (1-1.3), P value = 0.04, respectively. Occurrences of some respiratory symptoms were associated with duration on the job, while a positive family history of asthma is not associated with increased occurrence of symptoms. The mean (SD) FEV1 and FVC were significantly lower among the test group compared with the control

  9. Health-hazard evaluation report HETA 86-356-1930, Social Security District Office, Philadelphia, Pennsylvania

    SciTech Connect

    Burr, G.A.; Kline, M.K.

    1988-09-01

    In response to a request from the manager of the District Office of the Social Security Administration, located in Philadelphia, Pennsylvania, an investigation was made of possible hazardous working conditions at that site. Employees had experienced headaches and nausea perhaps arising from cigarette smoke, kerosene, and gasoline fumes. There were times when both kerosene and gasoline were stored at a gas station next to the office building. Interior carbon dioxide (CO/sub 2/) levels ranged from 800 to 1000 parts per million. Carbon monoxide levels were negligible. Temperatures ranged from 72 to 77 degrees. Relative humidity ranged from 39 to 50%. The authors recommend that air flows and rates be adjusted, the ventilation system be cleaned and corrected, and the gas station alter its schedule. Other recommendations included making technical adjustments to some equipment and making a complaint system and safety manual available to the employees.

  10. Evaluation of hazards in CO2 laser welding and related processes.

    PubMed

    Hietanen, M; Honkasalo, A; Laitinen, H; Lindroos, L; Welling, I; von Nandelstadh, P

    1992-04-01

    High-power CO2 lasers are used extensively in various industrial applications. In most cases they form part of open-beam equipment and have a power of several kilowatts, and are thus designated as Safety Class 4 systems. In addition to the invisible i.r. laser beam (10.6 microns), u.v. radiation and visible light may be emitted. In the present work a power meter controlled by microprocessor and a spectroradiometer measured the scattered or reflected laser radiation. In addition, concentration levels of welding and cutting fumes and of pyrolysis products of plastics were determined during various laser processes. Finally, a safety analysis was performed to compare the hazards of laser welding with those of conventional welding methods: this showed that the use of laser systems can eliminate many traditional risks, but the worker must be protected not only against the coherent laser beam, but also from incoherent blue light and u.v. radiation. PMID:1530233

  11. Short-term inhalation of stainless steel welding fume causes sustained lung toxicity but no tumorigenesis in lung tumor susceptible A/J mice.

    PubMed

    Zeidler-Erdely, Patti C; Battelli, Lori A; Stone, Sam; Chen, Bean T; Frazer, David G; Young, Shih-Houng; Erdely, Aaron; Kashon, Michael L; Andrews, Ronnee; Antonini, James M

    2011-02-01

    Debate exists as to whether welding fume is carcinogenic, but epidemiological evidence suggests that welders are an at-risk population for development of lung cancer. Our objective was to expose, by inhalation, lung tumor susceptible (A/J) and resistant C57BL/6J (B6) mice to stainless steel (SS) welding fume containing carcinogenic metals and characterize the lung-inflammatory and tumorigenic response. Male mice were exposed to air or gas metal arc (GMA)-SS welding fume at 40 mg/m(3)×3 h/day for 6 and 10 days. At 1, 4, 7, 10, 14, and 28 days after 10 days of exposure, bronchoalveolar lavage (BAL) was done. Lung cytotoxicity, permeability, inflammatory cytokines, and cell differentials were analyzed. For the lung tumor study, gross tumor counts and histopathological changes were assessed in A/J mice at 78 weeks after 6 and 10 days of exposure. Inhalation of GMA-SS fume caused an early, sustained macrophage and lymphocyte response followed by a gradual neutrophil influx and the magnitudes of these differed between the mouse strains. Monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-2 (MIP-2), and tumor necrosis factor-α (TNF-α) were increased in both strains while the B6 also had increased interleukin-6 (IL-6) protein. BAL measures of cytotoxicity and damage were similar between the strains and significantly increased at all time points. Histopathology and tumorigenesis were unremarkable at 78 weeks. In conclusion, GMA-SS welding fume induced a significant and sustained inflammatory response in both mouse strains with no recovery by 28 days. Under our exposure conditions, GMA-SS exposure resulted in no significant tumor development in A/J mice. PMID:21309664

  12. The California Hazards Institute

    NASA Astrophysics Data System (ADS)

    Rundle, J. B.; Kellogg, L. H.; Turcotte, D. L.

    2006-12-01

    California's abundant resources are linked with its natural hazards. Earthquakes, landslides, wildfires, floods, tsunamis, volcanic eruptions, severe storms, fires, and droughts afflict the state regularly. These events have the potential to become great disasters, like the San Francisco earthquake and fire of 1906, that overwhelm the capacity of society to respond. At such times, the fabric of civic life is frayed, political leadership is tested, economic losses can dwarf available resources, and full recovery can take decades. A patchwork of Federal, state and local programs are in place to address individual hazards, but California lacks effective coordination to forecast, prevent, prepare for, mitigate, respond to, and recover from, the harmful effects of natural disasters. Moreover, we do not know enough about the frequency, size, time, or locations where they may strike, nor about how the natural environment and man-made structures would respond. As California's population grows and becomes more interdependent, even moderate events have the potential to trigger catastrophes. Natural hazards need not become natural disasters if they are addressed proactively and effectively, rather than reactively. The University of California, with 10 campuses distributed across the state, has world-class faculty and students engaged in research and education in all fields of direct relevance to hazards. For that reason, the UC can become a world leader in anticipating and managing natural hazards in order to prevent loss of life and property and degradation of environmental quality. The University of California, Office of the President, has therefore established a new system-wide Multicampus Research Project, the California Hazards Institute (CHI), as a mechanism to research innovative, effective solutions for California. The CHI will build on the rich intellectual capital and expertise of the Golden State to provide the best available science, knowledge and tools for

  13. IDENTIFICATION OF AIRCRAFT HAZARDS

    SciTech Connect

    K.L. Ashley

    2005-03-23

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in the ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2004, Section 6.4.1). That determination was conservatively based on limited knowledge of flight data in the area of concern and on crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a Monitored Geologic Repository (MGR) at Yucca Mountain using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987, Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. NUREG-0800 is being used here as a reference because some of the same considerations apply. The intended use of this report is to provide inputs for further screening and analysis of the identified aircraft hazards based on the criteria that apply to Category 1 and 2 event sequence analyses as defined in 10 CFR 63.2 (see Section 4). The scope of this technical report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the MGR at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (see Section 7).

  14. Identification of Aircraft Hazards

    SciTech Connect

    K. Ashley

    2006-12-08

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2005 [DIRS 174235], Section 6.4.1). That determination was conservatively based upon limited knowledge of flight data in the area of concern and upon crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a monitored geologic repository (MGR) at Yucca Mountain, using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987 [DIRS 103124], Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. The intended use of this report is to provide inputs for further screening and analysis of identified aircraft hazards based upon the criteria that apply to Category 1 and Category 2 event sequence analyses as defined in 10 CFR 63.2 [DIRS 176544] (Section 4). The scope of this report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the repository at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (Section 7).

  15. Natural Hazards, Second Edition

    NASA Astrophysics Data System (ADS)

    Rouhban, Badaoui

    Natural disaster loss is on the rise, and the vulnerability of the human and physical environment to the violent forces of nature is increasing. In many parts of the world, disasters caused by natural hazards such as earthquakes, floods, landslides, drought, wildfires, intense windstorms, tsunami, and volcanic eruptions have caused the loss of human lives, injury, homelessness, and the destruction of economic and social infrastructure. Over the last few years, there has been an increase in the occurrence, severity, and intensity of disasters, culminating with the devastating tsunami of 26 December 2004 in South East Asia.Natural hazards are often unexpected or uncontrollable natural events of varying magnitude. Understanding their mechanisms and assessing their distribution in time and space are necessary for refining risk mitigation measures. This second edition of Natural Hazards, (following a first edition published in 1991 by Cambridge University Press), written by Edward Bryant, associate dean of science at Wollongong University, Australia, grapples with this crucial issue, aspects of hazard prediction, and other issues. The book presents a comprehensive analysis of different categories of hazards of climatic and geological origin.

  16. Temperature dependence of autogenous shrinkage of silica fume cement pastes with a very low water–binder ratio

    SciTech Connect

    Maruyama, I.; Teramoto, A.

    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.

  17. Enhancement of aged and denatured fingerprints using the cyanoacrylate fuming technique following dusting with amino acid-containing powders.

    PubMed

    Nixon, Carly; Almond, Matthew J; Baum, John V; Bond, John W

    2013-03-01

    We have carried out experiments to investigate the aging of latent fingerprints deposited on black PVC over a period of 4-15 weeks. A thumbprint was used in each case and before deposition of the print the donor rubbed their thumb around their nose to add sebaceous deposits. We have studied the effect of heat, light, and moisture and we find that moisture is the most significant factor in the degradation of the latent print. We have attempted to enhance these latent prints by dusting with valine powder or powders composed of valine mixed with gold or red fluorescent commercial fingerprint powders. To make a direct comparison between "treated" and "untreated" prints, the prints were cut in half with one-half being "treated" and one-half not. Our studies show the best results being obtained when powders of valine and red fluorescent powders are applied prior to cyanoacrylate fuming. PMID:23316682

  18. Application of TiO2 and fumed silica nanoparticles and improve the performance of drilling fluids

    NASA Astrophysics Data System (ADS)

    Cheraghian, Goshtasp; Hemmati, Mahmood; Bazgir, Saeed

    2014-03-01

    In these experiments, two nano particles dissolved that in water, are used to inject into simulated environment and also the effect of these nano particles in water base drilling typical fluid have been investigated. Using nanoparticles in all samples has resulted in recovery increase. Finally, considering the experiments, it is demonstrated that flows with nano and in particular Titanium dioxide nano(TiO2) have the highes amount of recovery factors. So, using nanoparticles in water flooding and even some of the polymer flooding ones. Also, results of the other tests, regarding each typical drilling costs of each foot and importance of time in the operation, it is possible to replace technically and economically ordinary additional (here, the widely used sodium hydroxide) with Fumed silica nano in drilling fluid to prevent cement-contamination of the drilling fluid. The advantages of nano TiO2 are possessing suitable thermal transition qualities in the drilling fluid.

  19. Hazardous materials dictionary

    SciTech Connect

    Coleman, R.J.

    1987-01-01

    Parallel growth of the chemical industry of emergency response capabilities in the public and private sectors has created a new need for improved communications. A new vocabulary of important terms is emerging in each of the industries that transport, store and handle hazardous materials. This dictionary, representing a compilation of words and phrases from many relevant sources, will help document and standardize the nomenclature of hazardous materials. The authors have screened the technical discourse of the chemical, transportation, petroleum and medical fields, both governmental and private, to determine the most current expressions and their uses. The lexicographic goal has been to identify key terms, ambiguous and multiple meaning words, acronyms, symbols and even slang referring to hazardous materials reactions, storing and handling procedures.

  20. Moral Hazard in Pediatrics.

    PubMed

    Brunnquell, Donald; Michaelson, Christopher M

    2016-07-01

    "Moral hazard" is a term familiar in economics and business ethics that illuminates why rational parties sometimes choose decisions with bad moral outcomes without necessarily intending to behave selfishly or immorally. The term is not generally used in medical ethics. Decision makers such as parents and physicians generally do not use the concept or the word in evaluating ethical dilemmas. They may not even be aware of the precise nature of the moral hazard problem they are experiencing, beyond a general concern for the patient's seemingly excessive burden. This article brings the language and logic of moral hazard to pediatrics. The concept reminds us that decision makers in this context are often not the primary party affected by their decisions. It appraises the full scope of risk at issue when decision makers decide on behalf of others and leads us to separate, respect, and prioritize the interests of affected parties. PMID:27292845

  1. Field comparison of three inhalable samplers (IOM, PGP-GSP 3.5 and Button) for welding fumes.

    PubMed

    Zugasti, Agurtzane; Montes, Natividad; Rojo, José M; Quintana, M José

    2012-02-01

    Inhalable sampler efficiency depends on the aerodynamic size of the airborne particles to be sampled and the wind speed. The aim of this study was to compare the behaviour of three personal inhalable samplers for welding fumes generated by Manual Metal Arc (MMA) and Metal Active Gas (MAG) processes. The selected samplers were the ones available in Spain when the study began: IOM, PGP-GSP 3.5 (GSP) and Button. Sampling was carried out in a welding training center that provided a homogeneous workplace environment. The static sampling assembly used allowed the placement of 12 samplers and 2 cascade impactors simultaneously. 183 samples were collected throughout 2009 and 2010. The range of welding fumes' mass concentrations was from 2 mg m(-3) to 5 mg m(-3). The pooled variation coefficients for the three inhalable samplers were less than or equal to 3.0%. Welding particle size distribution was characterized by a bimodal log-normal distribution, with MMADs of 0.7 μm and 8.2 μm. For these welding aerosols, the Button and the GSP samplers showed a similar performance (P = 0.598). The mean mass concentration ratio was 1.00 ± 0.01. The IOM sampler showed a different performance (P < 0.001). The mean mass concentration ratios were 0.90 ± 0.01 for Button/IOM and 0.92 ± 0.02 for GSP/IOM. This information is useful to consider the measurements accomplished by the IOM, GSP or Button samplers together, in order to assess the exposure at workplaces over time or to study exposure levels in a specific industrial activity, as welding operations. PMID:22037834

  2. Quantitative cancer risk assessment for occupational exposures to asphalt fumes during built-up roofing asphalt (BURA) operations.

    PubMed

    Rhomberg, Lorenz R; Mayfield, David B; Goodman, Julie E; Butler, Eric L; Nascarella, Marc A; Williams, Daniel R

    2015-01-01

    The International Agency for Research on Cancer qualitatively characterized occupational exposure to oxidized bitumen emissions during roofing as probably carcinogenic to humans (Group 2A). We examine chemistry, exposure, epidemiology and animal toxicity data to explore quantitative risks for roofing workers applying built-up roofing asphalt (BURA). Epidemiology studies do not consistently report elevated risks, and generally do not have sufficient exposure information or adequately control for confounders, precluding their use for dose-response analysis. Dermal carcinogenicity bioassays using mice report increased tumor incidence with single high doses. In order to quantify potential cancer risks, we develop time-to-tumor model methods [consistent with U.S. Environmental Protection Agency (EPA) dose-response analysis and mixtures guidelines] using the dose-time-response shape of concurrent exposures to benzo[a]pyrene (B[a]P) as concurrent controls (which had several exposure levels) to infer presumed parallel dose-time-response curves for BURA-fume condensate. We compare EPA relative potency factor approaches, based on observed relative potency of BURA to B[a]P in similar experiments, and direct observation of the inferred BURA dose-time-response (scaled to humans) as means for characterizing a dermal unit risk factor. We apply similar approaches to limited data on asphalt-fume inhalation and respiratory cancers in rats. We also develop a method for adjusting potency estimates for asphalts that vary in composition using measured fluorescence. Overall, the various methods indicate that cancer risks to roofers from both dermal and inhalation exposure to BURA are within a range typically deemed acceptable within regulatory frameworks. The approaches developed may be useful in assessing carcinogenic potency of other complex mixtures of polycyclic aromatic compounds. PMID:26515283

  3. Oxidative stress, telomere shortening, and DNA methylation in relation to low-to-moderate occupational exposure to welding fumes.

    PubMed

    Li, Huiqi; Hedmer, Maria; Wojdacz, Tomasz; Hossain, Mohammad Bakhtiar; Lindh, Christian H; Tinnerberg, Håkan; Albin, Maria; Broberg, Karin

    2015-10-01

    Evidence suggests that exposure to welding fumes is a risk factor for lung cancer. We examined relationships between low-to-moderate occupational exposure to particles from welding fumes and cancer-related biomarkers for oxidative stress, changes in telomere length, and alterations in DNA methylation. We enrolled 101 welders and 127 controls (all currently nonsmoking men) from southern Sweden. We performed personal sampling of respirable dust and measured 8-oxodG concentrations in urine using a simplified liquid chromatography tandem mass spectrometry method. Telomere length in peripheral blood was measured by quantitative polymerase chain reaction. Methylation status of 10 tumor suppressor genes was determined by methylation-sensitive high-resolution melting analysis. All analyses were adjusted for age, body mass index, previous smoking, passive smoking, current residence, and wood burning stove/boiler at home. Welders were exposed to respirable dust at 1.2 mg/m(3) (standard deviation, 3.3 mg/m(3); range, 0.1-19.3), whereas control exposures did not exceed 0.1 mg/m(3) (P < 0.001). Welders and controls did not differ in 8-oxodG levels (β = 1.2, P = 0.17) or relative telomere length (β = -0.053, P = 0.083) in adjusted models. Welders showed higher probability of adenomatous polyposis coli (APC) methylation in the unadjusted model (odds ratio = 14, P = 0.014), but this was not significant in the fully adjusted model (P = 0.052). Every working year as a welder was associated with 0.0066 units shorter telomeres (95% confidence interval -0.013 to -0.00053, P = 0.033). Although there were no clear associations between concentrations of respirable dust and the biomarkers, there were modest signs of associations between oxidative stress, telomere alterations, DNA methylation, and occupational exposure to low-to-moderate levels of particles. PMID:26013103

  4. Hazardous-Materials Robot

    NASA Technical Reports Server (NTRS)

    Stone, Henry W.; Edmonds, Gary O.

    1995-01-01

    Remotely controlled mobile robot used to locate, characterize, identify, and eventually mitigate incidents involving hazardous-materials spills/releases. Possesses number of innovative features, allowing it to perform mission-critical functions such as opening and unlocking doors and sensing for hazardous materials. Provides safe means for locating and identifying spills and eliminates risks of injury associated with use of manned entry teams. Current version of vehicle, called HAZBOT III, also features unique mechanical and electrical design enabling vehicle to operate safely within combustible atmosphere.

  5. Hazard Communication Standard

    SciTech Connect

    Sichak, S.

    1991-01-01

    The current rate of technological advances has brought with it an overwhelming increase in the usage of chemicals in the workplace and in the home. Coupled to this increase has been a heightened awareness in the potential for acute and chronic injuries attributable to chemical insults. The Hazard Communication Standard has been introduced with the desired goal of reducing workplace exposures to hazardous substances and thereby achieving a corresponding reduction in adverse health effects. It was created and proclaimed by the US Department of Labor and regulated by the Occupational Safety and Health Administration. 1 tab.

  6. Geothermal hazards - Mercury emission

    NASA Technical Reports Server (NTRS)

    Siegel, S. M.; Siegel, B. Z.

    1975-01-01

    Enthusiasm for intensified geothermal exploration may induce many participants to overlook a long-term potential toxicity hazard possibly associated with the tapping of magmatic steam. The association of high atmospheric Hg levels with geothermal activity has been established both in Hawaii and Iceland, and it has been shown that mercury can be introduced into the atmosphere from fumaroles, hot springs, and magmatic sources. These arguments, extended to thallium, selenium, and other hazardous elements, underscore the need for environmental monitoring in conjunction with the delivery of magmatic steam to the surface.

  7. Environmental lead hazard to children.

    PubMed

    Mittal, S K

    1992-01-01

    Clinically evident lead poisoning is rare in Indian children but is more common than in adults. In children, lead poisoning may appear as fever, seizures, anemia, or abdominal pain, while in adults it is more likely to manifest as chronic minor peripheral neuropathy or gum pigmentation. Children with acute lead poisoning can be treated with chelators such as EDTA and BAL, but many are left with permanent brain damage. The most common sources of acute lead poisoning in Indian children are inhalation of fumes from burned car batteries, ingestion of flaking paint, consuming food cooked in cheap aluminum or brass utensils, and eating contaminated soil. The sources of chronic lead poisoning are water from lead pipes and fumes from industrial or automotive exhaust. Another common source in India is application of "kajjal" to children's eyes. Sources of lead in Western countries, such as drinking water, canned food, residential paint, automotive fuel, and ambient air quality, are regulated by law. None of these are regulated in India. PMID:12318356

  8. Hazardous solvent substitution

    SciTech Connect

    Twitchell, K.E.

    1995-11-01

    Eliminating hazardous solvents is good for the environment, worker safety, and the bottom line. However, even though we are motivated to find replacements, the big question is `What can we use as replacements for hazardous solvents?`You, too, can find replacements for your hazardous solvents. All you have to do is search for them. Search through the vendor literature of hundreds of companies with thousands of products. Ponder the associated material safety data sheets, assuming of course that you can obtain them and, having obtained them, that you can read them. You will want to search the trade magazines and other sources for product reviews. You will want to talk to users about how well the product actually works. You may also want to check US Environmental Protection Agency (EPA) and other government reports for toxicity and other safety information. And, of course, you will want to compare the product`s constituent chemicals with the many hazardous constituency lists to ensure the safe and legal use of the product in your workplace.

  9. Hazardous Wastes from Homes.

    ERIC Educational Resources Information Center

    Lord, John

    The management of waste materials has become more complex with the increase in human population and the development of new substances. This illustrated booklet traces the history of waste management and provides guidelines for individuals and communities in disposing of certain hazardous wastes safely. It addresses such topics as: (1) how people…

  10. PERMITTING HAZARDOUS WASTE INCINERATORS

    EPA Science Inventory

    This publication is a compilation of information presented at a seminar series designed to address the issues that affect the issuance of hazardous waste incineration permits and to improve the overall understanding of trial burn testing. pecifically, the document provides guidan...

  11. Hazards of Mercury.

    ERIC Educational Resources Information Center

    Environmental Research, 1971

    1971-01-01

    Common concern for the protection and improvement of the environment and the enhancement of human health and welfare underscore the purpose of this special report on the hazards of mercury directed to the Secretary's Pesticide Advisory Committee, Department of Health, Education, and Welfare. The report summarizes the findings of a ten-member study…

  12. Wind shear hazard determination

    NASA Technical Reports Server (NTRS)

    Lewis, Michael S.

    1992-01-01

    The topics are presented in viewgraph form and include the following: F-factor relationship with aircraft performance; F-factor formulations; the F-bar index; F-factor hazard limit; F-bar with Doppler sensors; and F-bar profile composite.

  13. SCI Hazard Report Methodology

    NASA Technical Reports Server (NTRS)

    Mitchell, Michael S.

    2010-01-01

    This slide presentation reviews the methodology in creating a Source Control Item (SCI) Hazard Report (HR). The SCI HR provides a system safety risk assessment for the following Ares I Upper Stage Production Contract (USPC) components (1) Pyro Separation Systems (2) Main Propulsion System (3) Reaction and Roll Control Systems (4) Thrust Vector Control System and (5) Ullage Settling Motor System components.

  14. Tank farms hazards assessment

    SciTech Connect

    Broz, R.E.

    1994-09-30

    Hanford contractors are writing new facility specific emergency procedures in response to new and revised US Department of Energy (DOE) Orders on emergency preparedness. Emergency procedures are required for each Hanford facility that has the potential to exceed the criteria for the lowest level emergency, an Alert. The set includes: (1) a facility specific procedure on Recognition and Classification of Emergencies, (2) area procedures on Initial Emergency Response and, (3) an area procedure on Protective Action Guidance. The first steps in developing these procedures are to identify the hazards at each facility, identify the conditions that could release the hazardous material, and calculate the consequences of the releases. These steps are called a Hazards Assessment. The final product is a document that is similar in some respects to a Safety Analysis Report (SAR). The document could br produced in a month for a simple facility but could take much longer for a complex facility. Hanford has both types of facilities. A strategy has been adopted to permit completion of the first version of the new emergency procedures before all the facility hazards Assessments are complete. The procedures will initially be based on input from a task group for each facility. This strategy will but improved emergency procedures in place sooner and therefore enhance Hanford emergency preparedness. The purpose of this document is to summarize the applicable information contained within the Waste Tank Facility ``Interim Safety Basis Document, WHC-SD-WM-ISB-001`` as a resource, since the SARs covering Waste Tank Operations are not current in all cases. This hazards assessment serves to collect, organize, document and present the information utilized during the determination process.

  15. Counterfactual Volcano Hazard Analysis

    NASA Astrophysics Data System (ADS)

    Woo, Gordon

    2013-04-01

    The historical database of past disasters is a cornerstone of catastrophe risk assessment. Whereas disasters are fortunately comparatively rare, near-misses are quite common for both natural and man-made hazards. The word disaster originally means 'an unfavourable aspect of a star'. Except for astrologists, disasters are no longer perceived fatalistically as pre-determined. Nevertheless, to this day, historical disasters are treated statistically as fixed events, although in reality there is a large luck element involved in converting a near-miss crisis situation into a disaster statistic. It is possible to conceive a stochastic simulation of the past to explore the implications of this chance factor. Counterfactual history is the exercise of hypothesizing alternative paths of history from what actually happened. Exploring history from a counterfactual perspective is instructive for a variety of reasons. First, it is easy to be fooled by randomness and see regularity in event patterns which are illusory. The past is just one realization of a variety of possible evolutions of history, which may be analyzed through a stochastic simulation of an array of counterfactual scenarios. In any hazard context, there is a random component equivalent to dice being rolled to decide whether a near-miss becomes an actual disaster. The fact that there may be no observed disaster over a period of time may belie the occurrence of numerous near-misses. This may be illustrated using the simple dice paradigm. Suppose a dice is rolled every month for a year, and an event is recorded if a six is thrown. There is still an 11% chance of no events occurring during the year. A variety of perils may be used to illustrate the use of near-miss information within a counterfactual disaster analysis. In the domain of natural hazards, near-misses are a notable feature of the threat landscape. Storm surges are an obvious example. Sea defences may protect against most meteorological scenarios. However

  16. HAZARDOUS SUBSTANCES DATA BANK (HSDB)

    EPA Science Inventory

    Hazardous Substances Data Bank (HSDB) is a factual, non-bibliographic data bank focusing upon the toxicology of potentially hazardous chemicals. It is enhanced with data from such related areas as emergency handling procedures, environmental fate, human exposure, detection method...

  17. Hypothermia: A Cold Weather Hazard

    MedlinePlus

    ... Weather Hazard Heath and Aging Hypothermia: A Cold Weather Hazard What Are The Signs Of Hypothermia? Taking ... cold air. But, not everyone knows that cold weather can also lower the temperature inside your body. ...

  18. Autonomous Landing Hazard Avoidance Technology

    NASA Video Gallery

    Future NASA space crafts will be able to safely land on the Moon, Marsand even an asteroid, in potentially hazardous terrain areas, allautonomously. And NASA’s Autonomous Landing Hazard Avoidan...

  19. Hazardous Waste: Cleanup and Prevention.

    ERIC Educational Resources Information Center

    Vandas, Steve; Cronin, Nancy L.

    1996-01-01

    Describes the Superfund, a federal cleanup program created in response to growing public concern over the health and environmental risks posed by hazardous waste sites. Discusses sources, disposal, and movement and risk of hazardous waste. (JRH)

  20. Seismic hazard maps for Haiti

    USGS Publications Warehouse

    Frankel, Arthur; Harmsen, Stephen; Mueller, Charles; Calais, Eric; Haase, Jennifer

    2011-01-01

    We have produced probabilistic seismic hazard maps of Haiti for peak ground acceleration and response spectral accelerations that include the hazard from the major crustal faults, subduction zones, and background earthquakes. The hazard from the Enriquillo-Plantain Garden, Septentrional, and Matheux-Neiba fault zones was estimated using fault slip rates determined from GPS measurements. The hazard from the subduction zones along the northern and southeastern coasts of Hispaniola was calculated from slip rates derived from GPS data and the overall plate motion. Hazard maps were made for a firm-rock site condition and for a grid of shallow shear-wave velocities estimated from topographic slope. The maps show substantial hazard throughout Haiti, with the highest hazard in Haiti along the Enriquillo-Plantain Garden and Septentrional fault zones. The Matheux-Neiba Fault exhibits high hazard in the maps for 2% probability of exceedance in 50 years, although its slip rate is poorly constrained.

  1. Effects of Using Silica Fume and Polycarboxylate-Type Superplasticizer on Physical Properties of Cementitious Grout Mixtures for Semiflexible Pavement Surfacing

    PubMed Central

    Karim, Mohamed Rehan; Mahmud, Hilmi; Mashaan, Nuha S.; Katman, Herdayati; Husain, Nadiah Md

    2014-01-01

    Semi-flexible pavement surfacing is a composite pavement that utilizes the porous pavement structure of the flexible bituminous pavement, which is subsequently grouted with appropriate cementitious materials. This study aims to investigate the compressive strength, flexural strength, and workability performance of cementitious grout. The grout mixtures are designed to achieve high strength and maintain flow properties in order to allow the cement slurries to infiltrate easily through unfilled compacted skeletons. A paired-sample t-test was carried out to find out whether water/cement ratio, SP percentages, and use of silica fume influence the cementitious grout performance. The findings showed that the replacement of 5% silica fume with an adequate amount of superplasticizer and water/cement ratio was beneficial in improving the properties of the cementitious grout. PMID:24526911

  2. Mapping Europe's Seismic Hazard

    NASA Astrophysics Data System (ADS)

    Giardini, Domenico; Wössner, Jochen; Danciu, Laurentiu

    2014-07-01

    From the rift that cuts through the heart of Iceland to the complex tectonic convergence that causes frequent and often deadly earthquakes in Italy, Greece, and Turkey to the volcanic tremors that rattle the Mediterranean, seismic activity is a prevalent and often life-threatening reality across Europe. Any attempt to mitigate the seismic risk faced by society requires an accurate estimate of the seismic hazard.

  3. Publication: Evansville hazard maps

    USGS Publications Warehouse

    Evansville Area Earthquake Hazards Mapping Project

    2012-01-01

    The Evansville (Indiana) Area Earthquake Hazards Mapping Project was completed in February 2012. It was a collaborative effort among the U.S. Geological Survey and regional partners Purdue University; the Center for Earthquake Research and Information at the University of Memphis; the state geologic surveys of Kentucky, Illinois, and Indiana; the Southwest Indiana Disaster Resistant Community Corporation; and the Central U.S. Earthquake Consortium state geologists.

  4. Comprehensive baseline hazard assessments

    SciTech Connect

    Warren, S.B.; Amundson, T.M.

    1994-10-01

    Westinghouse Hanford Company (WHC) has developed and implemented a cost effective/value-added program/process that assists in fulfilling key elements of the Occupational Safety and Health Administration`s (OSHA) voluntary Protection Program (VPP) requirements. WHC is the prime contractor for the US Department of Energy (US DOE) at the Hanford site, located in Richland, Washington. The site consists of over 560 square miles, contains over 1100 facilities and has an employment of approximately 18,000. WHC is currently in the application review phase for the US DOE equivalent of OSHA-VPP ``merit`` program status. The program involves setting up a team consisting of industrial safety and health (industrial hygienists) professionals, members of the maintenance and operations work force, and facility management. This team performs a workplace hazard characterization/analysis and then applies a risk assessment approach to prioritize observed and potential hazards in need of abatement. The process involves using checklists that serve as a guide for evaluation/inspection criteria. Forms are used to document meetings, field observations, instrument calibration and performance testing. Survey maps are generated to document quality records of measurement results. A risk assessment code matrix with a keyword index was developed to facilitate consistency. The end product is useful in communicating hazards to facility management, health and safety professionals, audit/appraisal groups, and most importantly, facility workers.

  5. PUREX facility hazards assessment

    SciTech Connect

    Sutton, L.N.

    1994-09-23

    This report documents the hazards assessment for the Plutonium Uranium Extraction Plant (PUREX) located on the US Department of Energy (DOE) Hanford Site. Operation of PUREX is the responsibility of Westinghouse Hanford Company (WHC). This hazards assessment was conducted to provide the emergency planning technical basis for PUREX. DOE Order 5500.3A requires an emergency planning hazards assessment for each facility that has the potential to reach or exceed the lowest level emergency classification. In October of 1990, WHC was directed to place PUREX in standby. In December of 1992 the DOE Assistant Secretary for Environmental Restoration and Waste Management authorized the termination of PUREX and directed DOE-RL to proceed with shutdown planning and terminal clean out activities. Prior to this action, its mission was to reprocess irradiated fuels for the recovery of uranium and plutonium. The present mission is to establish a passively safe and environmentally secure configuration at the PUREX facility and to preserve that condition for 10 years. The ten year time frame represents the typical duration expended to define, authorize and initiate follow-on decommissioning and decontamination activities.

  6. Hazard Maps in the Classroom.

    ERIC Educational Resources Information Center

    Cross, John A.

    1988-01-01

    Emphasizes the use of geophysical hazard maps and illustrates how they can be used in the classroom from kindergarten to college level. Depicts ways that hazard maps of floods, landslides, earthquakes, volcanoes, and multi-hazards can be integrated into classroom instruction. Tells how maps may be obtained. (SLM)

  7. Identifying and modeling safety hazards

    SciTech Connect

    DANIELS,JESSE; BAHILL,TERRY; WERNER,PAUL W.

    2000-03-29

    The hazard model described in this paper is designed to accept data over the Internet from distributed databases. A hazard object template is used to ensure that all necessary descriptors are collected for each object. Three methods for combining the data are compared and contrasted. Three methods are used for handling the three types of interactions between the hazard objects.

  8. Hazardous Waste: Cleanup and Prevention.

    ERIC Educational Resources Information Center

    Vandas, Steve; Cronin, Nancy L.

    1996-01-01

    Discusses hazardous waste, waste disposal, unsafe exposure, movement of hazardous waste, and the Superfund clean-up process that consists of site discovery, site assessment, clean-up method selection, site clean up, and site maintenance. Argues that proper disposal of hazardous waste is everybody's responsibility. (JRH)

  9. Assessment of the biological effects of welding fumes emitted from metal inert gas welding processes of aluminium and zinc-plated materials in humans.

    PubMed

    Hartmann, L; Bauer, M; Bertram, J; Gube, M; Lenz, K; Reisgen, U; Schettgen, T; Kraus, T; Brand, P

    2014-03-01

    The aim of this study was to investigate biological effects and potential health risks due to two different metal-inert-gas (MIG) welding fumes (MIG welding of aluminium and MIG soldering of zinc coated steel) in healthy humans. In a threefold cross-over design study 12 male subjects were exposed to three different exposure scenarios. Exposures were performed under controlled conditions in the Aachener Workplace Simulation Laboratory (AWSL). On three different days the subjects were either exposed to filtered ambient air, to welding fumes from MIG welding of aluminium, or to fumes from MIG soldering of zinc coated materials. Exposure was performed for 6 h and the average fume concentration was 2.5 mg m(-3). Before, directly after, 1 day after, and 7 days after exposure spirometric and impulse oscillometric measurements were performed, exhaled breath condensate (EBC) was collected and blood samples were taken and analyzed for inflammatory markers. During MIG welding of aluminium high ozone concentrations (up to 250 μg m(-3)) were observed, whereas ozone was negligible for MIG soldering. For MIG soldering, concentrations of high-sensitivity CRP (hsCRP) and factor VIII were significantly increased but remained mostly within the normal range. The concentration of neutrophils increased in tendency. For MIG welding of aluminium, the lung function showed significant decreases in Peak Expiratory Flow (PEF) and Mean Expiratory Flow at 75% vital capacity (MEF 75) 7 days after exposure. The concentration of ristocetin cofactor was increased. The observed increase of hsCRP during MIG-soldering can be understood as an indicator for asymptomatic systemic inflammation probably due to zinc (zinc concentration 1.5 mg m(-3)). The change in lung function observed after MIG welding of aluminium may be attributed to ozone inhalation, although the late response (7 days after exposure) is surprising. PMID:23790592

  10. Flow and leakage characteristics of a sashless inclined air-curtain (sIAC) fume hood containing tall pollutant-generation tanks.

    PubMed

    Chen, Jia-Kun; Huang, Rong Fung; Hung, Wei-Lun

    2013-01-01

    In many fume hood applications, pollutant-generation devices are tall. Human operators of a fume hood must stand close to the front of the hood and lift up their hands to reach the top opening of the tall tank. In this situation, it is inconvenient to access the conventional hood because the sash acts as a barrier. Also, the bluff-body wake in front of the operator's chest causes a problem. By using laser-assisted smoke flow visualization and tracer-gas test methods, the present study examines a sashless inclined air-curtain (sIAC) fume hood for tall pollutant-generation tanks, with a mannequin standing in front of the hood face. The configuration of the sIAC fume hood, which had the important element of a backward-inclined push-pull air curtain, was different from conventional configurations. Depending on suction velocity, the backward-inclined air curtain had three characteristic modes: straight, concave, and attachment. A large recirculation bubble covering the area--from the hood ceiling to the work surface--was formed behind the inclined air curtain in the straight and concave modes. In the attachment mode, the inclined air curtain was attached to the rear wall of the hood, about 50 cm from the hood ceiling, and bifurcated into up and down streams. Releasing the pollutants at an altitude above where the inclined air curtain was attached caused the suction slot to directly draw up the pollutants. Releasing pollutants in the rear recirculation bubble created a risk of pollutants' leaking from the hood face. The tracer-gas (SF6) test results showed that operating the sIAC hood in the attachment mode, with the pollutants being released high above the critical altitude, could guarantee almost no leakage, even though a mannequin was standing in front of the sashless hood face. PMID:24195536

  11. Oxidative stress, telomere shortening, and DNA methylation in relation to low‐to‐moderate occupational exposure to welding fumes

    PubMed Central

    Li, Huiqi; Hedmer, Maria; Wojdacz, Tomasz; Hossain, Mohammad Bakhtiar; Lindh, Christian H.; Tinnerberg, Håkan; Albin, Maria

    2015-01-01

    Evidence suggests that exposure to welding fumes is a risk factor for lung cancer. We examined relationships between low‐to‐moderate occupational exposure to particles from welding fumes and cancer‐related biomarkers for oxidative stress, changes in telomere length, and alterations in DNA methylation. We enrolled 101 welders and 127 controls (all currently nonsmoking men) from southern Sweden. We performed personal sampling of respirable dust and measured 8‐oxodG concentrations in urine using a simplified liquid chromatography tandem mass spectrometry method. Telomere length in peripheral blood was measured by quantitative polymerase chain reaction. Methylation status of 10 tumor suppressor genes was determined by methylation‐sensitive high‐resolution melting analysis. All analyses were adjusted for age, body mass index, previous smoking, passive smoking, current residence, and wood burning stove/boiler at home. Welders were exposed to respirable dust at 1.2 mg/m3 (standard deviation, 3.3 mg/m3; range, 0.1–19.3), whereas control exposures did not exceed 0.1 mg/m3 (P < 0.001). Welders and controls did not differ in 8‐oxodG levels (β = 1.2, P = 0.17) or relative telomere length (β = −0.053, P = 0.083) in adjusted models. Welders showed higher probability of adenomatous polyposis coli (APC) methylation in the unadjusted model (odds ratio = 14, P = 0.014), but this was not significant in the fully adjusted model (P = 0.052). Every working year as a welder was associated with 0.0066 units shorter telomeres (95% confidence interval −0.013 to −0.00053, P = 0.033). Although there were no clear associations between concentrations of respirable dust and the biomarkers, there were modest signs of associations between oxidative stress, telomere alterations, DNA methylation, and occupational exposure to low‐to‐moderate levels of particles. Environ. Mol. Mutagen. 56:684–693, 2015. © 2015 The Authors

  12. Assessment of Occupational Exposure to Manganese and Other Metals in Welding Fumes by Portable X-ray Fluorescence Spectrometer

    PubMed Central

    Laohaudomchok, Wisanti; Cavallari, Jennifer M.; Fang, Shona C.; Lin, Xihong; Herrick, Robert F.; Christiani, David C.; Weisskopf, Marc G.

    2011-01-01

    Elemental analysis of welding fume samples can be done using several laboratory-based techniques. However, portable measurement techniques could offer several advantages. In this study, we sought to determine whether the portable X-ray fluorescence spectrometer (XRF) is suitable for analysis of five metals (manganese, iron, zinc, copper, and chromium) on 37-mm polytetrafluoroethylene filters. Using this filter fitted on a cyclone in line with a personal pump, gravimetric samples were collected from a group of boilermakers exposed to welding fumes. We assessed the assumption of uniform deposition of these metals on the filters, and the relationships between measurement results of each metal obtained from traditional laboratory-based XRF and the portable XRF. For all five metals of interest, repeated measurements with the portable XRF at the same filter area showed good consistency (reliability ratios are equal or close to 1.0 for almost all metals). The portable XRF readings taken from three different areas of each filter were not significantly different (p-values = 0.77 to 0.98). This suggested that the metal rich PM2.5 deposits uniformly on the samples collected using this gravimetric method. For comparison of the two XRFs, the results from the portable XRF were well correlated and highly predictive of those from the laboratory XRF. The Spearman correlation coefficients were from 0.325 for chromium, to 0.995 for manganese and 0.998 for iron. The mean differences as a percent of the mean laboratory XRF readings were also small (<5%) for manganese, iron, and copper. The differences were greater for zinc and chromium, which were present at very low amounts in our samples and below the limits of detection of the portable XRF for many of the samples. These five metals were moderately to strongly correlated with the total fine particle fraction on filters (Spearman ρ = 0.41 for zinc to 0.97 for iron). Such strong correlations and comparable results suggested that the

  13. Investigation of effect of fluoride on corrosion of 2S-0 aluminum and 347 stainless steel in fuming nitric acid at 170 F

    NASA Technical Reports Server (NTRS)

    Feiler, Charles E; Morrell, Gerald

    1954-01-01

    The effect of small additions of fluoride on the corrosion of 2S-0 aluminum and 347 stainless steel by fuming nitric acid at 170 degrees F has been evaluated quantitatively by the determination of the weight loss of metal specimens immersed in the acid. The ratio of metal surface area to volume of acid was approximately 7.5 inch (superscript)-1 in all cases. It was found that for acids containing no fluorides the weight loss of aluminum was approximately 1/5 that of stainless steel. Addition of 1 percent fluoride ion to the acid reduced the weight loss of both metals to practically zero even after 26 days of exposure to the acid at 170 degrees F. The minimum quantity of fluoride ion required to inhibit corrosion was found to be approximately 0.25 and 0.5 percent for aluminum and stainless steel, respectively, in white fuming nitric acid and 0.5 and 1 percent in red fuming nitric acid (18 percent nitrogen dioxide). These fluoride percentages were based on the total weight of acid. Provided the concentration of fluoride ion was sufficient to inhibit corrosion, the source of these ions was immaterial. Additional information concerning the effect of fluorides on corrosion was obtained by measuring the electrode potentials of the metals against a platinum reference electrode.

  14. Escaping the Tyranny of Carbothermal Reduction: Fumed Silica from Sustainable, Green Sources without First Having to Make SiCl4.

    PubMed

    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

  15. Explosion impacts during transport of hazardous cargo: GIS-based characterization of overpressure impacts and delineation of flammable zones for ammonia.

    PubMed

    Inanloo, Bahareh; Tansel, Berrin

    2015-06-01

    The aim of this research was to investigate accidental releases of ammonia followed by an en-route incident in an attempt to further predict the consequences of hazardous cargo accidents. The air dispersion model Areal Locations of Hazardous Atmospheres (ALOHA) was employed to track the probable outcomes of a hazardous material release of a tanker truck under different explosion scenarios. The significance of identification of the flammable zones was taken into consideration; in case the flammable vapor causes an explosion. The impacted areas and the severity of the probable destructions were evaluated for an explosion by considering the overpressure waves. ALOHA in conjunction with ArcGIS was used to delineate the flammable and overpressure impact zones for different scenarios. Based on the results, flammable fumes were formed in oval shapes having a chief axis along the wind direction at the time of release. The expansions of the impact areas under the overpressure value which can lead to property damage for 2 and 20 tons releases, under very stable and unstable atmospheric conditions were estimated to be around 1708, 1206; 3742, 3527 feet, respectively, toward the wind direction. A sensitivity analysis was done to assess the significance of wind speed on the impact zones. The insight provided by this study can be utilized by decision makers in transportation of hazardous materials as a guide for possible rerouting, rescheduling, or limiting the quantity of hazardous cargo to reduce the possible impacts after hazardous cargo accidents during transport. PMID:25781067

  16. Hazardous materials car placement in a train consist. Volume 1. Review and analysis. Final report, 18 Feb-17 Nov 88

    SciTech Connect

    Thompson, R.E.; Zamejc, E.R.; Ahlbeck, D.R.

    1992-06-01

    In response to major derailments involving hazardous materials cars, the Federal Railroad Administration (FRA) initiated the review of the consequences of hazardous materials car placement in a train consist. The review and analysis consisted of six task items: (1) review of accident trends and regulations, (2) an analysis of hazardous materials compatibility, (3) railroad operational constraints, (4) a cost/benefit analysis, (5) recommendations, and (6) preparation of a final report. A review of the 1982-1985 Railroad Accident/Icident Reporting System (RAIRS) data showed the rear quarter to be statistically the 'safest' location in a mainline freight train. Also, the top 101 hazardous commodities (by volume movement) plus fuming nitric acid were analyzed for chemical incompatibility, a total of 5,151 binary combinations. Consequence-based and risk-based rankings were established. Calculations established a post-derailment separation distance of 40 meters minimum to prevent mixing of incompatible chemicals. It was noted that mixing of hazmat materials was not cited in any NTSB accident report as a specific problem.

  17. Radiation Hazard Detector

    NASA Technical Reports Server (NTRS)

    1978-01-01

    NASA technology has made commercially available a new, inexpensive, conveniently-carried device for protection, of people exposed to potentially dangerous levels of microwave radiation. Microwaves are radio emissions of extremely high frequency. They can be hazardous but the degree of hazard is not yet well understood. Generally, it is believed that low intensity radiation of short duration is not harmful but that exposure to high levels can induce deep internal burns, affecting the circulatory and nervous systems, and particularly the eyes. The Department of Labor's Occupational Safety and Health Administration (OSHA) has established an allowable safe threshold of exposure. However, people working near high intensity sources of microwave energy-for example, radar antennas and television transmitters-may be unknowingly exposed to radiation levels beyond the safe limit. This poses not only a personal safety problem but also a problem for employers in terms of productivity loss, workman's compensation claims and possible liability litigation. Earlier-developed monitoring devices which warn personnel of dangerous radiation levels have their shortcomings. They can be cumbersome and awkward to use while working. They also require continual visual monitoring to determine if a person is in a dangerous area of radiation, and they are relatively expensive, another deterrent to their widespread adoption. In response to the need for a cheaper and more effective warning system, Jet Propulsion Laboratory developed, under NASA auspices, a new, battery-powered Microwave Radiation Hazard Detector. To bring the product to the commercial market, California Institute Research Foundation, the patent holder, granted an exclusive license to Cicoil Corporation, Chatsworth, California, an electronic components manufacturer.

  18. Interaction between Polymorphisms in Pre-MiRNA Genes and Cooking Oil Fume Exposure on the Risk of Lung Cancer in Chinese Non-Smoking Female Population

    PubMed Central

    Yin, Zhihua; Cui, Zhigang; Guan, Peng; Li, Xuelian; Wu, Wei; Ren, Yangwu; He, Qincheng; Zhou, Baosen

    2015-01-01

    Background 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. Methods 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. Results 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. Conclusions The interactions between miRNA SNPs and cooking oil fume exposure suggested by ORs of different combination were not statistically significant

  19. Immunological evaluation of four arc welders exposed to fumes from ignited polyurethane (isocyanate) foam: antibodies and immune profiles

    SciTech Connect

    Broughton, A.; Thrasher, J.D.; Gard, Z.

    1988-01-01

    Four arc welders having a flu-like illness with multiple health complaints following an exposure to high concentrations of isocyanate fumes from ignited polyurethane foam underwent immunological tests as follows: ELISA antibody assays, activated lymphocyte profiles, and lymphocyte blastogenesis. ELISA procedures revealed the presence of antibodies to hexamethylene diisocyanate (HDI) and formaldehyde (F) conjugated to human serum albumin (HDI-SA and F-SA). The results from the activated lymphocyte profiles showed deviations from the norm as follows: three welders had elevated helper/suppressor (H/S) ratios; all four had elevated percentages of Tal positive cells; two had decreases in B cells; and one had low total white cell and lymphocyte counts. In contrast, the percentage and absolute numbers of ILS receptor cells were normal in the four subjects. T cell blastogenesis to PHA, Con A and PWM resulted in the following: T-cells from one subject responded normally; in another, a high response (212% of controls) to PHA occurred with normal mitogenesis to Con A and PWM. In the remaining two welders, the T cells responded abnormally low (50 to 75% of controls) to the three mitogens. In conclusion, the existence of IgG antibodies to HDI-SA and F-SA, the altered activated immune profiles, the elevated Tal cells, and the abnormal blastogenesis are interpreted as being linked with the episode of HDI and F exposure and the subsequent flu-like illness of the four welders.

  20. Inhalation exposure of gas-metal arc stainless steel welding fume increased atherosclerotic lesions in apolipoprotein E knockout mice.

    PubMed

    Erdely, Aaron; Hulderman, Tracy; Salmen-Muniz, Rebecca; Liston, Angie; Zeidler-Erdely, Patti C; Chen, Bean T; Stone, Samuel; Frazer, David G; Antonini, James M; Simeonova, Petia P

    2011-07-01

    Epidemiological studies suggest that welding, a process which generates an aerosol of inhalable gases and metal rich particulates, increases the risk for cardiovascular disease. In this study we analyzed systemic inflammation and atherosclerotic lesions following gas metal arc-stainless steel (GMA-SS) welding fume exposure. Apolipoprotein E knockout (apoE(-/-)) mice, fed a Western diet, were exposed to GMA-SS at 40mg/m(3) for 3h/day for ten days (∼8.26μg daily alveolar deposition). Mice were sacrificed two weeks after exposure and serum chemistry, serum protein profiling and aortic lesion area were determined. There were no significant changes in serum total cholesterol, triglycerides or alanine aminotransferase. Serum levels of uric acid, a potent antioxidant, were decreased perhaps suggesting a reduced capacity to combat systemic oxidative stress. Inflammatory serum proteins interleukin 1 beta (IL-1β) and monocyte chemoattractant protein 3 (MCP-3) were increased two weeks after GMA-SS exposure. Analysis of atherosclerotic plaques showed an increase in lesion area as the result of GMA-SS exposure. In conclusion, GMA-SS exposure showed evidence of systemic inflammation and increased plaque progression in apoE(-/-) mice. These results complement epidemiological and functional human studies that suggest welding may result in adverse cardiovascular effects. PMID:21513782

  1. Effects on Chinese restaurant workers of exposure to cooking oil fumes: a cautionary note on urinary 8-hydroxy-2'-deoxyguanosine.

    PubMed

    Pan, Chih-Hong; Chan, Chang-Chuan; Wu, Kuen-Yuh

    2008-12-01

    This study evaluates oxidative DNA damage in workers who are exposed to cooking oil fumes (COFs) in Chinese restaurants. The study participants were 387 nonsmoking Chinese restaurant workers, 202 kitchen staff, and 185 service staff at 23 Chinese restaurants in Taiwan. Airborne particulate matter and particulate polycyclic aromatic hydrocarbon levels were monitored in kitchens and dining areas. Urinary 1-hydroxypyrene (1-OHP) was used as an internal dose of exposure to COFs, and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) was used as an oxidative DNA damage marker. The relationship between workers' 8-OHdG and 1-OHP levels was estimated using linear mixed-effects models. Airborne particulate matter and polycyclic aromatic hydrocarbons levels in kitchens significantly exceeded those in dining areas. The kitchen staff's geometric mean levels of urinary 8-OHdG (7.9 microg/g creatinine) and 1-OHP (4.5 microg/g creatinine) were significantly higher than those of the service staff, which were 5.4 and 2.7 microg/g creatinine, respectively. Urinary 1-OHP level, work in kitchens, gender, and work hours per day were four significant predictors of urinary 8-OHdG levels after adjustments are made for covariates. Oxidative DNA damage was associated with exposure of Chinese restaurant workers to COFs. Female restaurant workers had a greater oxidative stress response to COFs than male restaurant workers, providing additional evidence of the link between lung cancer in Chinese women and exposure to COFs. PMID:19064550

  2. Annual decline in forced expiratory volume is steeper in aluminum potroom workers than in workers without exposure to potroom fumes

    PubMed Central

    Henneberger, Paul K.; Einvik, Gunnar; Virji, Mohammed Abbas; Bakke, Berit; Kongerud, Johny

    2016-01-01

    Background Aluminum potroom exposure is associated with increased mortality of COPD but the association between potroom exposure and annual decline in lung function is unknown. We have measured lung volumes annually using spirometry from 1986 to 1996. The objective was to compare annual decline in forced expiratory volume in 1 s (dFEV1) and forced vital capacity (dFVC). Methods The number of aluminum potroom workers was 4,546 (81% males) and the number of workers in the reference group was 651 (76% males). The number of spirometries in the index group and the references were 24,060 and 2,243, respectively. Results After adjustment for confounders, the difference in dFEV1 and dFVC between the index and reference groups were 13.5 (P < 0.001) and −8.0 (P = 0.060) ml/year. Conclusion Aluminum potroom operators have increased annual decline in FEV1 relative to a comparable group with non‐exposure to potroom fumes and gases. Am. J. Ind. Med. 59:322–329, 2016. © 2016 The Authors. American Journal of Industrial Medicine Published by Wiley Periodicals, Inc. PMID:26853811

  3. Integration of chemical scrubber with sodium hypochlorite and surfactant for removal of hydrocarbons in cooking oil fume.

    PubMed

    Cheng, Hsin-Han; Hsieh, Chu-Chin

    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(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(L)a, liquid/gas ratio, pH and C(NaOCl). PMID:20633996

  4. Development of nanocomposite based on hydroxyethylmethacrylate and functionalized fumed silica: mechanical, chemico-physical and biological characterization.

    PubMed

    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

  5. Toxic Hazards Research Unit

    NASA Technical Reports Server (NTRS)

    Macewen, J. D.; Vernot, E. H.

    1971-01-01

    The activities of the Toxic Hazards Research Unit (THRU) for the period of June 1970 through May 1971 reviewed. Modification of the animal exposure facilities primarily for improved human safety but also for experimental integrity and continuity are discussed. Acute toxicity experiments were conducted on hydrogen fluoride (HF), hydrogen chloride (HCl), nitrogen dioxide (NO2), and hydrogen cyanide (HCN) both singly and in combination with carbon dioxide (CO). Additional acute toxicity experiments were conducted on oxygen difluoride (OF2) and chlorine pentafluoride (ClF5). Subacute toxicity studies were conducted on methylisobutylketone and dichloromethane (methylene dichloride). The interim results of further chronic toxicity experiments on monomethylhydrazine (MMH) are also described.

  6. Hazardous Environment Robotics

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Jet Propulsion Laboratory (JPL) developed video overlay calibration and demonstration techniques for ground-based telerobotics. Through a technology sharing agreement with JPL, Deneb Robotics added this as an option to its robotics software, TELEGRIP. The software is used for remotely operating robots in nuclear and hazardous environments in industries including automotive and medical. The option allows the operator to utilize video to calibrate 3-D computer models with the actual environment, and thus plan and optimize robot trajectories before the program is automatically generated.

  7. Health Hazard Evaluation Report HETA-80-073-1589, Marion Power Shovel, Marion, Ohio. [Core and mold areas (MDI binders)

    SciTech Connect

    Stephenson, R.L.; Liss, G.M.

    1985-04-01

    Environmental and breathing-zone samples were analyzed for methylene-bisphenyl-isocyanate (MDI), total reactive isocyanate groups (TRIG), triethylamine, mineral spirits, and metal fume at Marion Power Shovel Foundry, Marion, Ohio, in March and September, 1983. The evaluation was requested by the union to assess exposures in the core and mold areas where MDI binders were used. Interviews were conducted with 26 exposed and 13 nonexposed workers. Medical examinations that included pulmonary function and immunological testing, and chest x-rays were administered. All exposures were below the OSHA standards for TRIG. Previously obtained silica monitoring data was reviewed. Silica overexposure was indicated. Twenty-seven exposed workers reported lower respiratory tract symptoms consistent with occupational asthma. The authors conclude that significant exposures to isocyanates have occurred at the facility. A health hazard due to silica also exists. Recommendations include establishing a medical surveillance program for MDI and reducing silica exposures by appropriate engineering controls.

  8. 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.

    PubMed

    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

  9. Incineration of hazardous wastes.

    PubMed

    Gannon, T; Ansbro, A R; Burns, R P

    1991-10-01

    Glaxo has practiced incineration of liquid and gaseous wastes for over twenty years and currently operate eleven liquid and gas incinerators in the United Kingdom and Singapore. The liquid incinerators burn, as their main streams, those solvents that cannot be recovered and recycled within the processes. The early installations were for readily combustible solvents only. However, there has been a progressive move into the destruction of more difficult and hazardous wastes, with the consequential requirements for more sophisticated technology, in the belief that the responsible destruction of waste should be tackled near to its source. The eventual aim is to be self-sufficient in this area of waste management. The incineration of hazardous liquid and gaseous waste has presented a series of design, operational and monitoring problems into account which have all been successfully overcome. The solutions take into account the environmental consequences of the operations from both liquid and gaseous emissions. In order to ensure minimal environmental impact and safe operation the best practicable technology is employed. Environmental assessment forms part of the process development and permitting procedures. PMID:24233930

  10. Hazards assessment for the Hazardous Waste Storage Facility

    SciTech Connect

    Knudsen, J.K.; Calley, M.B.

    1994-04-01

    This report documents the hazards assessment for the Hazardous Waste Storage Facility (HWSF) located at the Idaho National Engineering Laboratory. The hazards assessment was performed to ensure that this facility complies with DOE and company requirements pertaining to emergency planning and preparedness for operational emergencies. The hazards assessment identifies and analyzes hazards that are significant enough to warrant consideration in a facility`s operational emergency management program. The area surrounding HWSF, the buildings and structures at HWSF, and the processes used at HWSF are described in this report. All nonradiological hazardous materials at the HWSF were identified (radiological hazardous materials are not stored at HWSF) and screened against threshold quantities according to DOE Order 5500.3A guidance. Two of the identified hazardous materials exceeded their specified threshold quantity. This report discusses the potential release scenarios and consequences associated with an accidental release for each of the two identified hazardous materials, lead and mercury. Emergency considerations, such as emergency planning zones, emergency classes, protective actions, and emergency action levels, are also discussed based on the analysis of potential consequences. Evaluation of the potential consequences indicated that the highest emergency class for operational emergencies at the HWSF would be a Site Area Emergency.

  11. Time dependent seismic hazard

    NASA Astrophysics Data System (ADS)

    Polidoro, B.; Iervolino, I.; Chioccarelli, E.; Giorgio, M.

    2012-04-01

    Probabilistic seismic hazard is usually computed trough a homogeneous Poisson process that even though it is a time-independent process it is widely used for its very convenient properties. However, when a single fault is of concern and/or the time scale is different from that of the long term, time-dependent processes are required. In this paper, different time-dependent models are reviewed with working examples. In fact, the Paganica fault (in central Italy) has been considered to compute both the probability of occurrence of at least one event in the lifespan of the structure, as well as the seismic hazard expressed in terms of probability of exceedance of an intensity value in a given time frame causing the collapse of the structure. Several models, well known or novel application to engineering hazard have been considered, limitation and issues in their applications are also discussed. The Brownian Passage Time (BPT) model is based on a stochastic modification of the deterministic stick-slip oscillator model for characteristic earthquakes; i.e., based on the addition of random perturbations (a Gaussian white noise) to the deterministic load path predicted by elastic rebound theory. This model assumes that the load state is at some ground level immediately after an event, increases steadly over time, reaches a failure threshold and relaxes instantaneously back to the ground level. For this model also a variable threshold has been considered to take into account the uncertainty of the threshold value. For the slip-predictable model it is assumed that the stress accumulates at a constant rate starting from some initial stress level. Stress is assumed to accumulate for a random period of time until an earthquake occurs. The size of the earthquake is governed by the stress release and it is a function of the elapsed time since the last event. In the time-predictable model stress buildup occurs at a constant rate until the accumulated stress reaches a threshold

  12. The inverse hazard law: blood pressure, sexual harassment, racial discrimination, workplace abuse and occupational exposures in US low-income black, white and Latino workers.

    PubMed

    Krieger, Nancy; Chen, Jarvis T; Waterman, Pamela D; Hartman, Cathy; Stoddard, Anne M; Quinn, Margaret M; Sorensen, Glorian; Barbeau, Elizabeth M

    2008-12-01

    Research on societal determinants of health suggests the existence of an "inverse hazard law," which we define as: "The accumulation of health hazards tends to vary inversely with the power and resources of the populations affected." Yet, little empirical research has systematically investigated this topic, including in relation to workplace exposures. We accordingly designed the United for Health study (Greater Boston Area, Massachusetts, 2003-2004) to investigate the joint distribution and health implications of workplace occupational hazards (dust, fumes, chemical, noise, ergonomic strain) and social hazards (racial discrimination, sexual harassment, workplace abuse). Focusing on blood pressure as our health outcome, we found that among the 1202 low-income multi-racial/ethnic working class participants in our cohort - of whom 40% lived below the US poverty line - 79% reported exposure to at least one social hazard and 82% to at least one high-exposure occupational hazard. Only sexual harassment, the least common social hazard, was associated with elevated systolic blood pressure (SBP) among the women workers. By contrast, no statistically significant associations were detectable between the other additional highly prevalent social and occupational hazards and SBP; we did, however, find suggestive evidence of an association between SBP and response to unfair treatment, implying that in a context of high exposure, differential susceptibility to the exposure matters. These results interestingly contrast to our prior findings for this same cohort, in which we found associations between self-reported experiences of racial discrimination and two other health outcomes: psychological distress and cigarette smoking. Likely explanations for these contrasting findings include: (a) the differential etiologic periods and pathways involving somatic health, mental health, and health behaviors, and (b) the high prevalence of adverse exposures, limiting the ability to detect

  13. Health hazard evaluation report HETA 82-093-1453, Southwest Power Station City Utilities, Springfield, Missouri

    SciTech Connect

    Zey, J.N.; Aw, T.C.

    1984-04-01

    In response to a request from the Safety Department of City Utilities to evaluate employee exposures to coal and other dusts and fumes at the Southwest Power Facility (SIC-4911), Springfield, Missouri a visit was made to the site. All personal coal dust, fly ash, crystalline silica (14808607), nitrogen-dioxide (10102440), nitric-oxide (10102439), and sulfuric-acid (7664939) samples were below the lowest current criterion level. Four of eight personal sulfur-dioxide (7446095) samples exceeded the NIOSH recommended criterion of 1.3mg/cu m. Medical evaluation resulted in the identification of three workers with chronic bronchitis each of whom smoked cigarettes, eight workers with pulmonary function test abnormalities indicating obstructive airways disease, and two workers with features of restrictive lung disease. One chest X-ray was consistent with pneumoconiosis. The authors conclude that a health hazard existed for employees exposed to sulfur-dioxide and noise. A potential hazard also existed for employee exposure to heat stress in certain locations in the facility. The authors recommend improvements in the respiratory protection program, use of personal protective equipment, and initiation of an employee training program and environmental monitoring by management.

  14. Health-hazard evaluation report HETA 87-232-1948, Consolidated Freightways, Pocono Summit, Pennsylvania

    SciTech Connect

    Blade, L.M.; Savery, H.

    1989-02-01

    A study was made of possible hazardous working conditions at Consolidated Freightways, Pocono Summit, Pennsylvania. The request concerned potential exposure of dock workers to exhaust emissions from diesel-powered forklift trucks brought about by the health complaints of several of the workers there. Twenty-one workers were identified as symptomatic of exposure to diesel exhaust fumes. This included at least half of the midnight shift. Upper respiratory tract irritation was mentioned by all of these workers. Some reported eye irritation, cough productive of black-tinged sputum, and sore throat. These symptoms lessened during periods away from work. Airborne concentrations of all components measured at the site were well below the applicable exposure limits. A potential health hazard associated with exposure to diesel engine exhaust existed. The authors recommend that whenever a forklift truck is to be left unattended for more than the shortest of periods, the motor should be turned off. The newer forklifts should be used on a shift before the older, less emission controlled, lifts. Roof exhaust fans ordered are to be installed at the facility and their effectiveness evaluated.

  15. Runoff inundation hazard cartography

    NASA Astrophysics Data System (ADS)

    Pineux, N.; Degré, A.

    2012-04-01

    Between 1998 and 2004, Europe suffered from more than hundred major inundations, responsible for some 700 deaths, for the moving of about half a million of people and the economic losses of at least 25 billions Euros covered by the insurance policies. Within this context, EU launched the 2007/60/CE directive. The inundations are natural phenomenon. They cannot be avoided. Nevertheless this directive permits to better evaluate the risks and to coordinate the management measures taken at member states level. In most countries, inundation maps only include rivers' overflowing. In Wallonia, overland flows and mudflows also cause huge damages, and must be included in the flood hazard map. Indeed, the cleaning operations for a village can lead to an estimated cost of 11 000 €. Average construction cost of retention dams to control off-site damage caused by floods and muddy flows was valued at 380 000€, and yearly dredging costs associated with these retention ponds at 15 000€. For a small city for which a study was done in a more specific way (Gembloux), the mean annual cost for the damages that can generate the runoff is about 20 000€. This cost consists of the physical damages caused to the real estate and movable properties of the residents as well as the emergency operations of the firemen and the city. On top of damages to public infrastructure (clogging of trenches, silting up of retention ponds) and to private property by muddy flows, runoff generates a significant loss of arable land. Yet, the soil resource is not an unlimited commodity. Moreover, sediments' transfer to watercourses alters their physical and chemical quality. And that is not to mention the increased psychological stress for people. But to map overland flood and mud flow hazard is a real challenge. This poster will present the methodology used to in Wallonia. The methodology is based on 3 project rainfalls: 25, 50 and 100 years return period (consistency with the cartography of the

  16. Hazardous materials incineration system

    SciTech Connect

    Hladun, K.W.

    1982-03-23

    A hazardous materials incineration system is disclosed which includes a solid waste combustor of the inclined, oscillating or rocking type and a liquid waste combustor suitable to incinerate wastes in liquid form. The combustion products from both the solid waste combustor and the liquid waste combustor are fed to an afterburner which is equipped with burners to maintain elevated temperatures throughout the length of the afterburner chamber. The products of combustion exit the afterburner into a conditioning unit which eliminates larger particulate matter, cools the combustion products and releases certain additives into the moving gas stream prior to entry into a baghouse. All neutralized salts are withdrawn at the baghouse and the gaseous baghouse effluent is directed to a further aqueous liquor contact apparatus prior to exhausting to atmosphere through a forced draft stack system.

  17. Hazards of explosives dusts

    NASA Astrophysics Data System (ADS)

    The Bureau of Mines has investigated the hazards of military explosives dispersed as dust clouds in a 20-L test chamber. For purposes of personnel safety, the spark ignitability of the explosives in the form of unconfined dust layers was also studied. The 20-L data show that most of the explosive dusts were capable of sustaining explosions as dust clouds dispersed in air and some dusts were even capable of sustaining explosions when dispersed in nitrogen. The finest sizes of explosive dusts were less reactive than the larger sizes; this is opposite to the particle size effect observed previously for the pure fuel dusts. The data for the explosive dusts were compared to those for pure fuel dusts.

  18. Health hazards of photography.

    PubMed

    Rosenthal, J; Forst, L

    2001-01-01

    Photographers are exposed to chemical, physical, and psychological hazards during the course of their work. Photojournalists are at physical risk from motor vehicle crashes and work in war zones. Ergonomic risk comes from handling heavy equipment as well as work in awkward postures in dangerous positions. Darkroom exposure to chemical agents may lead to respiratory, allergic, and nervous system disease. Psychological problems come from chaotic work organization. Digital photography may reduce the prevalence of chemical exposure, although it may increase the risk of musculoskeletal illness. Simple hygiene measures may prevent illness in photographers. An increasing number of printed resources is available to professional and amateur photographers; this information may help them protect their health while they enjoy their art. PMID:11567918

  19. Secondary impact hazard assessment

    NASA Technical Reports Server (NTRS)

    1986-01-01

    A series of light gas gun shots (4 to 7 km/sec) were performed with 5 mg nylon and aluminum projectiles to determine the size, mass, velocity, and spatial distribution of spall and ejecta from a number of graphite/epoxy targets. Similar determinations were also performed on a few aluminum targets. Target thickness and material were chosen to be representative of proposed Space Station structure. The data from these shots and other information were used to predict the hazard to Space Station elements from secondary particles resulting from impacts of micrometeoroids and orbital debris on the Space Station. This hazard was quantified as an additional flux over and above the primary micrometeoroid and orbital debris flux that must be considered in the design process. In order to simplify the calculations, eject and spall mass were assumed to scale directly with the energy of the projectile. Other scaling systems may be closer to reality. The secondary particles considered are only those particles that may impact other structure immediately after the primary impact. The addition to the orbital debris problem from these primary impacts was not addressed. Data from this study should be fed into the orbital debris model to see if Space Station secondaries make a significant contribution to orbital debris. The hazard to a Space Station element from secondary particles above and beyond the micrometeoroid and orbital debris hazard is categorized in terms of two factors: (1) the 'view factor' of the element to other Space Station structure or the geometry of placement of the element, and (2) the sensitivity to damage, stated in terms of energy. Several example cases were chosen, the Space Station module windows, windows of a Shuttle docked to the Space Station, the habitat module walls, and the photovoltaic solar cell arrays. For the examples chosen the secondary flux contributed no more than 10 percent to the total flux (primary and secondary) above a given calculated

  20. Tsunami: The Underrated Hazard

    NASA Astrophysics Data System (ADS)

    Synolakis, Costas; Fryer, Gerard J.

    Tsunami: the Underrated Hazard, by Edward Bryant, would appear to be a welcome addition to the scholarly tsunami literature. No book on tsunamis has the broad perspective of this work. The book looks attractive, with many high-quality photographs. It looks comprehensive, with discussions of tsunami hydrodynamics, tsunami effects on coastal landscapes, and causes of tsunamis (earthquakes, landslides, volcanic eruptions, meteorite impacts). It looks practical, with a section on risk and mitigation. It also looks entertaining, with an opening chapter on tsunami legends and a closing chapter presenting fanciful descriptions of imagined events. Appearances are deceiving, though. Any initial enthusiasm for the work evaporates on even casual reading. The book is so flawed by errors, omissions, confusion, and unsupported conjecture that we cannot recommend it to anyone.

  1. Secondary impact hazard assessment

    NASA Astrophysics Data System (ADS)

    1986-06-01

    A series of light gas gun shots (4 to 7 km/sec) were performed with 5 mg nylon and aluminum projectiles to determine the size, mass, velocity, and spatial distribution of spall and ejecta from a number of graphite/epoxy targets. Similar determinations were also performed on a few aluminum targets. Target thickness and material were chosen to be representative of proposed Space Station structure. The data from these shots and other information were used to predict the hazard to Space Station elements from secondary particles resulting from impacts of micrometeoroids and orbital debris on the Space Station. This hazard was quantified as an additional flux over and above the primary micrometeoroid and orbital debris flux that must be considered in the design process. In order to simplify the calculations, eject and spall mass were assumed to scale directly with the energy of the projectile. Other scaling systems may be closer to reality. The secondary particles considered are only those particles that may impact other structure immediately after the primary impact. The addition to the orbital debris problem from these primary impacts was not addressed. Data from this study should be fed into the orbital debris model to see if Space Station secondaries make a significant contribution to orbital debris. The hazard to a Space Station element from secondary particles above and beyond the micrometeoroid and orbital debris hazard is categorized in terms of two factors: (1) the 'view factor' of the element to other Space Station structure or the geometry of placement of the element, and (2) the sensitivity to damage, stated in terms of energy. Several example cases were chosen, the Space Station module windows, windows of a Shuttle docked to the Space Station, the habitat module walls, and the photovoltaic solar cell arrays. For the examples chosen the secondary flux contributed no more than 10 percent to the total flux (primary and secondary) above a given calculated

  2. Landslide Hazard in Georgia

    NASA Astrophysics Data System (ADS)

    Gaprindashvili, George; Tsereteli, Emil; Gaprindashvili, Merab

    2014-05-01

    In the last decades of the XX century, protect the population from geological hazards, to maintain land and safe operation of the engineering facilities has become the most important social - economic, demographic, political and environmental problems for the whole world. Georgia, with its scales of origination of the natural-catastrophic processes (landslide, mudflow, rockfall, erosion and etc.), their re-occurrence and with the negative results inflicted by these processes to the population, agricultural lands and engineering objects, is one of the most complex mountainous region. The extremely sensitive conditions were conditioned by: 1. Activation of highly intense earthquakes; 2. Activation of the negative meteorological events provoking the disaster processes on the background of global climatic changes and their abnormally frequent occurrence (mostly increased atmospheric precipitations, temperature and humidity); 3. Large-scale Human impact on the environment. Following the problem urgency, a number of departmental and research institutions have made their operations more intense in the given direction within the limits of their competence. First of all, the activity of the Department of Geology of Georgia (which is at present included in the National Environmental Agency of the Ministry of Environment and Natural Resources Protection), which mapped, identified and cataloged the hazardous processes on the territory of the country and identified the spatial limits and developmental regularities of these processes for tens of years. The increased risk of Geological catastrophes in Georgia first of all is caused by insufficient information between society and responsible persons toward this event. The existed situation needs the base assessment of natural disasters level, the identification of events, to determine their caused reasons, to develop special maps in GIS system, and continuous functioning of geo monitoring researches for develop safety early

  3. Landslide Hazard in Georgia

    NASA Astrophysics Data System (ADS)

    Gaprindashvili, G.; Tsereteli, E.; Gaprindashvili, M.

    2013-12-01

    In the last decades of the XX century, protect the population from geological hazards, to maintain land and safe operation of the engineering facilities has become the most important social - economic, demographic, political and environmental problems for the whole world. Georgia, with its scales of origination of the natural-catastrophic processes (landslide, mudflow, rockfall, erosion and etc.), their re-occurrence and with the negative results inflicted by these processes to the population, agricultural lands and engineering objects, is one of the most complex mountainous region. The extremely sensitive conditions were conditioned by: 1. Activation of highly intense earthquakes; 2. Activation of the negative meteorological events provoking the disaster processes on the background of global climatic changes and their abnormally frequent occurrence (mostly increased atmospheric precipitations, temperature and humidity); 3. Large-scale Human impact on the environment. Following the problem urgency, a number of departmental and research institutions have made their operations more intense in the given direction within the limits of their competence. First of all, the activity of the Department of Geology of Georgia (which is at present included in the National Environmental Agency of the Ministry of Environment and Natural Resources Protection), which mapped, identified and cataloged the hazardous processes on the territory of the country and identified the spatial limits and developmental regularities of these processes for tens of years. The increased risk of Geological catastrophes in Georgia first of all is caused by insufficient information between society and responsible persons toward this event. The existed situation needs the base assessment of natural disasters level, the identification of events, to determine their caused reasons, to develop special maps in GIS system, and continuous functioning of geo monitoring researches for develop safety early

  4. Informing Workers of Chemical Hazards: The OSHA Hazard Communication Standard.

    ERIC Educational Resources Information Center

    American Chemical Society, Washington, DC.

    Practical information on how to implement a chemical-related safety program is outlined in this publication. Highlights of the federal Occupational Safety and Health Administrations (OSHA) Hazard Communication Standard are presented and explained. These include: (1) hazard communication requirements (consisting of warning labels, material safety…

  5. The structural and functional effects of fine particulate matter from cooking oil fumes on rat umbilical cord blood vessels.

    PubMed

    Zhu, Xiaoxia; Hou, Lijuan; Zhang, Jian; Yao, Cijiang; Liu, Ying; Zhang, Chao; Xu, Yachun; Cao, Jiyu

    2016-08-01

    A growing body of epidemiological evidence has supported the association between maternal exposure to airborne fine particulate matter (PM2.5) during pregnancy and adverse pregnancy outcomes. However, the specific biological mechanisms implicated in the causes of adverse pregnancy outcomes are not well defined. In this study, a pregnant rat model of exposure to different doses of cooking oil fumes (COFs)-derived PM2.5 by tail intravenous injection in different pregnant stages was established. The results indicated that exposure to COFs-derived PM2.5 was associated with adverse pregnancy outcomes, changed the structure of umbilical cord blood vessels, decreased the diameter and lumen area, and increased wall thickness. What's more, a significant increase of maximum contraction tension was observed in the early pregnancy high-dose exposure group and pregnant low-dose exposure group compared to the control group. Based on the maximum contraction tension, acetylcholine (ACh) did not induce vasodilation but caused a dose-dependent constriction, and there were significant differences in the two groups compared to the control group. Exposure to COFs-derived PM2.5 impaired the vasomotor function of umbilical veins by affecting the expression of NO and ET-1. This is the first study that evaluated the association of risk of adverse pregnancy outcomes and pregnant rats exposed to COFs-derived PM2.5 and primarily explored the potential mechanisms of umbilical cord blood vessels injury on a rat model. More detailed vitro and vivo studies are needed to further explore the mechanism in the future. PMID:27178289

  6. Solid-state 27Al and 29Si NMR characterization of hydrates formed in calcium aluminate silica fume mixtures

    NASA Astrophysics Data System (ADS)

    Pena, P.; Rivas Mercury, J. M.; de Aza, A. H.; Turrillas, X.; Sobrados, I.; Sanz, J.

    2008-08-01

    Partially deuterated Ca 3Al 2(SiO 4) y(OH) 12-4y-Al(OH) 3 mixtures, prepared by hydration of Ca 3Al 2O 6 (C 3A), Ca 12Al 14O 33 (C 12A 7) and CaAl 2O 4 (CA) phases in the presence of silica fume, have been characterized by 29Si and 27Al magic-angle spinning-nuclear magnetic resonance (MAS-NMR) spectroscopies. NMR spectroscopy was used to characterize anhydrous and fully hydrated samples. In hydrated compounds, Ca 3Al 2(OH) 12 and Al(OH) 3 phases were detected. From the quantitative analysis of 27Al NMR signals, the Al(OH) 3/Ca 3Al 2(OH) 12 ratio was deduced. The incorporation of Si into the katoite structure, Ca 3Al 2(SiO 4) 3-x(OH) 4x, was followed by 27Al and 29Si NMR spectroscopies. Si/OH ratios were determined from the quantitative analysis of 27Al MAS-NMR components associated with Al(OH) 6 and Al(OSi)(OH) 5 environments. The 29Si NMR spectroscopy was also used to quantify the unreacted silica and amorphous calcium aluminosilicate hydrates formed, C-S-H and C-A-S-H for short. From 29Si NMR spectra, the amount of Si incorporated into different phases was estimated. Si and Al concentrations, deduced by NMR, transmission electron microscopy, energy dispersive spectrometry, and Rietveld analysis of both X-ray and neutron data, indicate that only a part of available Si is incorporated in katoite structures.

  7. Influence of fumed silicon dioxide on the stabilization of Eudragit RS/RL 30 D film-coated theophylline pellets.

    PubMed

    Kucera, Shawn A; Stimpel, Doreen; Shah, Navnit H; Malick, A Waseem; Infeld, Martin H; McGinity, James W

    2008-01-01

    The objective of this study was to investigate the influence of various grades of fumed silicon dioxide on the drug release rate and physical aging of theophylline pellets coated with Eudragit RS 30 D and RL 30 D. Free films were assessed for both physicomechanical properties and water vapor permeability with respect to time and storage conditions. The release rate of theophylline was influenced by the physical properties of the silicon dioxide employed. As the particle size of the silica dioxide decreased, there was an increase in dispersion viscosity, as well as a decrease in the theophylline release rate from the coated pellets. Films prepared from formulas containing Aeroperl 300 had twice the water vapor transmission rate of films prepared from formulas containing Aerosil 200 VV and Cab-O-Sil M-5P and showed consistent moisture permeability values during storage for up to 1 month at 25 degrees C/0% relative humidity (RH). Scanning electron microscopy (SEM) imaging of pellets coated with a formulation containing Aerosil 200 VV or Cab-O-Sil M-5P demonstrated film structures that were homogenous, while those coated with a formulation containing Aeroperl 300 produced heterogeneous films with large particles of the excipient present within the polymeric matrix of the film. Stability in the drug release rate exhibited by pellets coated with a formulation containing Eudragit RS 30 D, 15% triethyl citrate (TEC), and 30% Aeroperl 300 was attributed to the stabilization of the moisture vapor transmission rate of the acrylic films. Increasing the concentration of Aeroperl 300 in the coating formulation increased the theophylline release rate from coated pellets. PMID:18484493

  8. In situ formation of sintered cordierite–mullite nano–micro composites by utilizing of waste silica fume

    SciTech Connect

    Khattab, R.M.; EL-Rafei, A.M.; Zawrah, M.F.

    2012-09-15

    Highlights: ► We succeeded to obtain in situ formed sintered cordierite–mullite nano–macro composites from waste and pure materials at 1400 °C. ► Their sinterability was greatly dependent on both firing temperature and composition. ► XRD patterns showed that the optimum temperature required for formation of sintered cordierite–mullite nano–macro composites was achieved at 1400 °C. ► The batch containing 70 wt.% cordierite and 30 wt.% mullite exhibited the best properties. ► Microstructures of the densified composites were composed of nano–macro cordierite–mullite structures. -- Abstract: This study aims at in situ formation of sintered cordierite–mullite nano–macro composites having high technological properties using waste silica fume, calcined ball clay, calcined alumina, and magnesia as starting materials. The starting materials were mixed in different ratios to obtain different cordierite–mullite composite batches in which the cordierite contents ranged from 50 to 100 wt.%. The batches were uni-axially pressed at 100 MPa and sintered at 1350, 1400 and 1450 °C to select the optimum temperature required for cordierite–mullite nano–macro composites formation. The formed phases were identified by X-ray diffraction (XRD) pattern. The sintering parameters in terms of bulk density (BD) and apparent porosity (AP) were determined. The microstructure of composites has been investigated by scanning electron microscope (SEM). Cold crushing strength (CCS) of the sintered batches was evaluated. The result revealed that the cordierite–mullite nano–macro composites were in-situ formed at 1400 °C. The batch containing 70 wt.% cordierite showed good physical and mechanical properties.

  9. Flow and containment characteristics of a sash-less, variable-height inclined air-curtain fume hood.

    PubMed

    Huang, Rong Fung; Chen, Jia-Kun; Hung, Wei-Lun

    2013-08-01

    To increase containment efficiency and reduce energy consumption, a sash-less, variable-height inclined air-curtain fume hood (sIAC hood) was developed and tested by a laser-assisted flow visualization technique and tracer-gas detection method. This novel design requires neither sash nor baffle. The sIAC hood employed the inclined push-pull air-curtain technique and two deflection plates installed on the side walls of the hood to induce a tetra-vortex flow structure. The results of flow visualization showed that the slot for suction flow, offset from the slot for the up-blowing jet, caused the air curtain to incline towards the rear wall, thus enhancing the robustness of the tetra-vortex flow structure. Such a flow structure could reduce the influence of draught and human walk-by across the hood face. The containment around the central area of the hood was isolated by the inclined push-pull air curtain. The pollutants carried by the reverse flow induced by the flow separation were guided by the deflection plates from the side walls towards the rear, thus contributing to the formation of the tetra-vortex flow structure. The up/down movable ceiling positioned the suction slot close to the device's pollutant emission opening, but left room (less than 50 cm) for unrestricted hand movement. Testing was carried out based on the methodology described in EN14175. The results of a static test showed that small face velocities of 0.25 and 0.16 m s(-1) were enough to obtain nearly null leakage levels for low and tall pollutant sources. The results of a traversing plate test showed that the face velocity, 0.32 m s(-1), would cause negligibly small leakage levels. The sIAC hood could obtain significantly higher containment efficiency than a conventional hood by operating at a face velocity significantly lower than that of conventional hoods. PMID:23519947

  10. Health effects of hazardous waste.

    PubMed

    Dearwent, Steve M; Mumtaz, M Moiz; Godfrey, Gail; Sinks, Thomas; Falk, Henry

    2006-09-01

    Since 1995, the Agency for Toxic Substances and Disease Registry (ATSDR) has evaluated environmental contaminants and human health risks at nearly 3000 sites. Hazardous substances at these sites include newly emerging problems as well as historically identified threats. ATSDR classifies sites according to the degree of hazard they represent to the public. Less than 1% of the sites investigated are considered urgent public health hazards where chemical or physical hazards are at levels that could cause an immediate threat to life or health. Approximately 20% of sites have a potential for long-term human exposures above acceptable risk levels. At almost 40% of sites, hazardous substances do not represent a public health hazard. Completed exposure pathways for contaminants in air, water, and soil have been reported at approximately 30% of evaluated sites. The most common contaminants of concern at these sites include heavy metals, volatile organic compounds, and polychlorinated biphenyls. This article reviews ATSDR's ongoing work by examining the historic hazard of lead, the contemporary hazard of asbestos, and the emerging issue of perchlorate contamination. PMID:17119223

  11. Michigan Household Hazardous Substance Handbook.

    ERIC Educational Resources Information Center

    Senior, Janet; Stone Nancy

    Common household hazardous substances include cleansers, drain cleaners, automotive products, paints, solvents, and pesticides. This handbook was designed to serve as a resource for people frequently contacted by the public for information on household hazardous substances and wastes. Included in the handbook are: (1) an introduction to Michigan's…

  12. Laboratory Safety and Chemical Hazards.

    ERIC Educational Resources Information Center

    Journal of Chemical Education, 1983

    1983-01-01

    Toxicology/chemical hazards, safety policy, legal responsibilities, adequacy of ventilation, chemical storage, evaluating experimental hazards, waste disposal, and laws governing chemical safety were among topics discussed in 10 papers presented at the Seventh Biennial Conference on Chemical Education (Stillwater, Oklahoma 1982). Several topics…

  13. THE CLASSIFICATION OF HAZARDOUS OCCUPATIONS

    PubMed Central

    Hayhurst, E. R.

    1916-01-01

    In this paper Doctor Hayhurst describes the six classifications for hazardous occupations which were employed in a survey made in Ohio. He also explains, by text and diagram, the process of analyzing, upon a standard formula, the hazard of an individual case. PMID:18009453

  14. Determination of Cr(VI) in welding fumes by anion-exchange fast protein liquid chromatography with electrothermal atomic absorption spectrometric detection.

    PubMed

    Milacic, Radmila; Scancar, Janez; Tusek, Janez

    2002-02-01

    The applicability of an anion-exchange fast protein liquid chromatographic-electrothermal atomic absorption spectrometric procedure (FPLC-ETAAS) was investigated for the determination of Cr(VI) in welding fumes after alkaline extraction of aerosols loaded on filters. Gas tungsten arc welding (GTAW) of stainless steel was applied. Samples of welding fumes were collected during regular welding on polycarbonate membrane filters of 8 microm and 0.4 microm pore size (inhalable and respirable aerosols). Alkaline extraction (2% NaOH-3% Na2CO3) of filters in a heated ultrasonic bath was applied to leach Cr from the airborne particulate matter. 0.5 cm3 of sample extract was then injected onto an anion-exchange FPLC column. Tris-HCl buffer (0.005 mol dm(-3), pH 8.0) and the same buffer with NaCl (0.5 mol dm(-3)) were employed in gradient elution (15 min, flow rate 1 cm3 min(-1)). The separated Cr species were determined "off line" by ETAAS in 0.5 cm3 fractions. Cr(VI) was reproducibly and quantitatively eluted from 12.0 to 13.0 min with a maximum peak at 12.5 min. Good repeatability of measurement (+/-3.0%) of alkaline extracts was obtained for Cr(VI). The LOD (3s) was found to be 0.035 microg m(-3) Cr(VI), when 2 m3 of aerosols were collected on the filter. Validation of the procedure was performed by spiking alkaline extracts and by the analysis of standard reference material CRM 545, Cr(VI) in welding dust loaded on a filter. The technique was successfully applied for the determination of Cr(VI) in welding fumes. PMID:11939630

  15. Hazardous waste: cleanup and prevention

    USGS Publications Warehouse

    Vandas, Stephen; Cronin, Nancy L.; Farrar, Frank, (artist); Serrano, Guillermo Eliezer Ávila, (translator); Yajimovich, Oscar Efraín González; Muñoz, Aurora R.; Rivera, María del C.

    1996-01-01

    Our lifestyles are supported by complex Industrial activities that produce many different chemicals and chemical wastes. The Industries that produce our clothing, cars, medicines, paper, food, fuels, steel, plastics, and electric components use and discard thousands of chemicals every year. At home we may use lawn chemicals, solvents, disinfectants, cleaners, and auto products to Improve our quality of life. A chemical that presents a threat or unreasonable risk to people or the environment Is a hazardous material. When a hazardous material can no longer be used, It becomes a hazardous waste. Hazardous wastes come from a variety of sources, from both present and past activities. Impacts to human health and the environment can result from Improper handling and disposal of hazardous waste.

  16. Size Distribution and Estimated Respiratory Deposition of Total Chromium, Hexavalent Chromium, Manganese, and Nickel in Gas Metal Arc Welding Fume Aerosols

    PubMed Central

    Cena, Lorenzo G.; Chisholm, William P.; Keane, Michael J.; Cumpston, Amy; Chen, Bean T.

    2016-01-01

    A laboratory study was conducted to determine the mass of total Cr, Cr(VI), Mn, and Ni in 15 size fractions for mild and stainless steel gas-metal arc welding (GMAW) fumes. Samples were collected using a nano multi orifice uniform deposition impactor (MOUDI) with polyvinyl chloride filters on each stage. The filters were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) and ion chromatography. Limits of detection (LODs) and quantitation (LOQs) were experimentally calculated and percent recoveries were measured from spiked metals in solution and dry, certified welding-fume reference material. The fraction of Cr(VI) in total Cr was estimated by calculating the ratio of Cr(VI) to total Cr mass for each particle size range. Expected, regional deposition of each metal was estimated according to respiratory-deposition models. The weight percent (standard deviation) of Mn in mild steel fumes was 9.2% (6.8%). For stainless steel fumes, the weight percentages were 8.4% (5.4%) for total Cr, 12.2% (6.5%) for Mn, 2.1% (1.5%) for Ni and 0.5% (0.4%) for Cr(VI). All metals presented a fraction between 0.04 and 0.6 μm. Total Cr and Ni presented an additional fraction <0.03 μm. On average 6% of the Cr was found in the Cr(VI) valence state. There was no statistical difference between the smallest and largest mean Cr(VI) to total Cr mass ratio (p-value D 0.19), hence our analysis does not show that particle size affects the contribution of Cr(VI) to total Cr. The predicted total respiratory deposition for the metal particles was ∼25%. The sites of principal deposition were the head airways (7–10%) and the alveolar region (11–14%). Estimated Cr(VI) deposition was highest in the alveolar region (14%). PMID:26848207

  17. 49 CFR 386.72 - Imminent hazard.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Imminent hazard. 386.72 Section 386.72... Injunctions and Imminent Hazards § 386.72 Imminent hazard. (a) Whenever it is determined that an imminent hazard exists as a result of the transportation by motor vehicle of a particular hazardous material,...

  18. 78 FR 42998 - Hazardous Materials: Improving the Safety of Railroad Transportation of Hazardous Materials

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-18

    ... TRANSPORTATION Federal Railroad Administration Hazardous Materials: Improving the Safety of Railroad Transportation of Hazardous Materials AGENCY: Pipeline and Hazardous Materials, Safety Administration (PHMSA... participate in a public meeting addressing the transportation of hazardous materials by rail. FRA and...

  19. Hazard interaction analysis for multi-hazard risk assessment: a systematic classification based on hazard-forming environment

    NASA Astrophysics Data System (ADS)

    Liu, B.; Siu, Y. L.; Mitchell, G.

    2015-12-01

    This paper develops a systematic hazard interaction classification based on the geophysical environment that natural hazards arise from - the hazard-forming environment. According to their contribution to natural hazards, geophysical environmental factors in the hazard-forming environment were categorized into two types. The first are relatively stable factors which construct the precondition for the occurrence of natural hazards, whilst the second are trigger factors, which determine the frequency and magnitude of hazards. Different combinations of geophysical environmental factors induce different hazards. Based on these geophysical environmental factors for some major hazards, the stable factors are used to identify which kinds of natural hazards influence a given area, and trigger factors are used to classify the relationships between these hazards into four types: independent, mutex, parallel and series relationships. This classification helps to ensure all possible hazard interactions among different hazards are considered in multi-hazard risk assessment. This can effectively fill the gap in current multi-hazard risk assessment methods which to date only consider domino effects. In addition, based on this classification, the probability and magnitude of multiple interacting natural hazards occurring together can be calculated. Hence, the developed hazard interaction classification provides a useful tool to facilitate improved multi-hazard risk assessment.

  20. Hazard interaction analysis for multi-hazard risk assessment: a systematic classification based on hazard-forming environment

    NASA Astrophysics Data System (ADS)

    Liu, Baoyin; Siu, Yim Ling; Mitchell, Gordon

    2016-03-01

    This paper develops a systematic hazard interaction classification based on the geophysical environment that natural hazards arise from - the hazard-forming environment. According to their contribution to natural hazards, geophysical environmental factors in the hazard-forming environment were categorized into two types. The first are relatively stable factors which construct the precondition for the occurrence of natural hazards, whilst the second are trigger factors, which determine the frequency and magnitude of hazards. Different combinations of geophysical environmental factors induce different hazards. Based on these geophysical environmental factors for some major hazards, the stable factors are used to identify which kinds of natural hazards influence a given area, and trigger factors are used to classify the relationships between these hazards into four types: independent, mutex, parallel and series relationships. This classification helps to ensure all possible hazard interactions among different hazards are considered in multi-hazard risk assessment. This can effectively fill the gap in current multi-hazard risk assessment methods which to date only consider domino effects. In addition, based on this classification, the probability and magnitude of multiple interacting natural hazards occurring together can be calculated. Hence, the developed hazard interaction classification provides a useful tool to facilitate improved multi-hazard risk assessment.