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At least 1,351 records · Page 75Linked to original sources
PubMed1980

A retrospective cohort study of mortality among stainless steel welders.

Hexavalent chromium particles are generated in the welding of stainless steel. These particles have manifested a mutagenic action in bacterial test systems and produced chromosome aberrations in cultured Chinese hamster cells. Welders who had welded stainless steel for more than 5 a during 1950--1965 were selected for this study. According to an earlier survey the hexavalent chromium exposure of such welders was often about 50 microgram/m3 (calculated as CrO3). The cohort was followed until December 1977. The expected number of deaths was calculated from cause-, gender-, age-, and year-specific death rates of the general population in Sweden. In the cohort, consisting of 234 welders, the observed numbers of total deaths and deaths caused by tumors were the same as the expected numbers. However, three welders had died of pulmonary tumors in comparison to the expected number of 0.68 (p = 0.03).

Aged↗
PubMed1977

Trace-element concentrations in blood samples from welders of stainless steel or aluminium and a reference group.

The concentrations of 17 trace elements (e.g., copper, cobalt, iron, manganese, chromium, silicon and magnesium) were determined in whole blood samples of 81 persons working with different welding methods on stainless steel or aluminium and 68 nonwelders. Inorganic spark source mass spectrometry was used for the chemical analyses. The data were analyzed by the SIMCA method for pattern recognition (discriminant analysis). No differences were found between the five groups, either in the average levels of the trace elements or in the correlation structures between the trace elements. Thus no blood concentration data on the analyzed elements and collected from a single person contained any information with respect to exposure to the welding fumes investigated.

Aluminum↗
PubMed1975

[The role of several occupational factors in the development of pulmonary alveolar proteinosis (an experimental study)].

The article deals with results of morphological and electron-microscopy studies of the lungs in experimental pulmonary alveolar proteinosis in rats. The disease was reproduced in experiments on 500 animals by means of chronic inhalation of electro-welding copper-containing aerosols, condensations (smokes) which may develop under similar concentrations during electric welding. The lungs were investigated at intervals ranging from several days to two years from the beginning of the experiment, the duration of which was 9 months, the dayly exposure of the animals in inhalation cameras being three hours. The intra-alveolar content was composed of products of accelerated life activity of the cells of the alveolar epithelium as well as of perished phagocytes (proteins, lipids). The degree of manifestation of the process depended upon concentration of aerosol and duration of the experiment. In the zones of pulmonary alveolar proteinosis there were observed thickenings of the basal membranes, sclerosis of interalveolar partitions, slow replacement of perished macrophages by new ones, which were the causes of prolonged resolution of the alveols content. Pulmonary alveolar proteinosis (lipoproteinosis) should not be considered as a variety of pneumonia or edema of alveols.

Air Pollutants↗
PubMed2003

[Diffuse alveolar damage after inhalation of zinc oxide fumes].

A 57-year-old man with a 37-year occupational history of welding was admitted for high fever and dyspnea after inhalation of zinc oxide fumes during a period of welding without a protective mask. Chest radiography and CT showed bilateral diffuse ground-glass opacities, and blood gas analysis revealed that PaO2 was 48.1 torr in room air. A transbronchial lung biopsy was done, and revealed diffuse alveolar damage. We diagnosed the case as chemical pneumonia due to the inhalation of zinc oxide, and prescribed prednisolone 40 mg per day. As a result, his symptoms improved within several days. The inhalation of zinc oxide fume usually causes metal fume fever, but chemical pneumonia is also reported on rare occasions. As far as our examination of the literature has disclosed, this is the first report of diffuse alveolar damage after inhalation of zinc oxide fume.

Humans↗
PubMed1992

Work-related electrocutions involving portable power tools and appliances.

Portable power tools and appliances can be identified as the source of injury in approximately 9% of occupational electrocutions. A search of fatality records for 1984 through 1986 in National Institute for Occupational Safety and Health (NIOSH) and Occupational Safety and Health Administration (OSHA) data bases identified 102 electrocutions involving portable appliances and tools that used 110-volt AC and 33 deaths involving welding equipment, which usually operates on 220-volt AC or higher. Of these 102 deaths, 51 occurred in the construction industry, 13 in services, 13 in manufacturing, and 25 in other industries. Plumbing contractors (Standard Industrial Classification [SIC] 1711) had the largest number of deaths (15) in construction. Powered hand-tools were involved in 58 deaths, with electric drills (23) and saws (13) the two largest classes. Proper provision of ground-fault circuit interrupter protection, particularly at temporary work sites, could have prevented most of the deaths from 110-volt AC. Engineering controls for preventing electrocution from portable arc-welding equipment should be evaluated.

Accidents, Occupational↗
PubMed2003

[A study on microstructures and heat reaction zone of laser-melted and cast post-keepers].

OBJECTIVE: In order to introduce the laser welding technology into root-cap making, this study compared the surface characters and internal structures of laser-melted and cast post-keeper to provide experimental data for clinical application of the technique. METHODS: Using untreated keeper as the control group, the surface characters and metallographic structures of the keepers were examined by stereomicroscope, metallographic microscope and SEM, and element analysis were conducted with EPMA. RESULTS: The laser-melted post-keeper basically kept the original smooth and the internal structure of the keeper, the heat reaction zone was extremely small and elements diffused mutually around the fusion zone obviously. While in the cast post-keeper, the surface was rough and had an oxide-layer. The internal structure changed and a fusion band formed between the base alloy and the keeper, but element diffusion was limited to the fusion zone. CONCLUSION: Compared with casting, laser welding technique demonstrated less influence on the surface and internal structure of the keepers.

Dental Alloys↗
PubMed2003

[The measurement of retentive force of laser-melted and cast post-keepers of Magfit magnetic attachments].

OBJECTIVE: In order to compare the influence of casting and laser welding on magnetic retentive force, the magnetic retentive forces of laser-melted and cast post-keepers of the magnetic attachments were measured in vitro. METHODS: 5 cast and 6 laser-melted post-keeper specimens (Magfit MD800) were formed, respectively. Using untreated keeper as control group, the vertical magnetic retentive forces were measured by a universal testing machine. RESULTS: The average vertical magnetic retentive force of the laser-melted post-keeper group and the cast post-keeper group in vitro were (4.223 +/- 0.217,0)N, (3.792,9 +/- 0.296,4)N, respectively. Compared with the cast post-keeper group, the average vertical magnetic retentive force of the laser-melted post-keeper groups was much higher in vitro (P < 0.05). CONCLUSION: Laser welding had less influence on the magnetic retentive force of the magnetic attachments than casting.

Dental Alloys↗
PubMed2004

A comparative evaluation of the tensile strength of silver soldered joints of stainless steel and cobalt chromium orthodontic wires with band material--an in vitro study.

The present study was conducted to compare and evaluate the tensile strength of silver soldered joints of stainless steel and cobalt-chromium orthodontic wires with band material. An attempt was made to observe the effect of joint site preparation by incorporation of tack welding and increasing metal to metal surface contact area by flattening an end of the wire prior to soldering along with the regularly used round wires without tack welding. A total of 180 wire specimens were soldered to 180 band specimens. Fifteen samples according to joint site preparation were included for each of the wire groups i.e. Gloria (S.S.), Remanium (S.S.) and Remaloy (Co-Cr) wires of 0.036" in diameter. The findings of the study were suggestive that all three wires may be used for preparing silver soldered joints irrespective of the quality of the wire. However, when subjecting the wire to joint site preparation, Gloria (S.S.) wire showed less tensile strength as compared to Remanium and Remaloy.

Analysis of Variance↗
PubMed2005

Through a glass, darkly.

The technology available in today's auto-darkening welding helmets was the stuff of science fiction to welders 30 years ago. A single lens capable of darkening automatically to a variable, preset shade level the instant an arc is struck would have sounded about as realistic as a "Star Trek"-style "transporter" or a cell phone that can take pictures. "It would have been complete and total science fiction," said Kevin Coughlin, president of Hoodlum Welding Gear, Minneapolis. "The technology really didn't exist, so it would be like me telling you your car will be flying in 20 years--you'd look at me and laugh. Even 25 years ago, if someone had told me [the lens] would go from clear to dark when you spark, I'd have said, 'Yeah, right, sure it does.' "

Eye Protective Devices↗
PubMed1991

[The effect of the working conditions on the development of diseases in cast-iron welders].

It was established that during cast-iron welding unfavourable factors of this production are welding aerosols, thermal and physical loads, radiation of the optical range. Results of detailed medical screening evidence that 80% of cast-iron welders showed pathology of the internal organs. Diseases of the bronchopulmonary apparatus occupy the leading place and are registered in every second cast-iron welder. The incidence rises with increased length of work and age.

Humans↗
PubMed1978

[Health conditions of a group of factory arc welders].

73 welders were examined, who weld in an assembly room of a machine factory, mainly by an electric arc. In anamneses 60% of persons under examination notified of coughing, expectorating, dyspnoea during work, and frequent acute rhinitis. Clinical symptoms of respiratory tract disease, resulting from welding, were found in 10% of welders. Simple bronchitis, resistant bronchitis with pulmonary emphysema, pleural adhesions were diagnosed. In one case fibronodular tuberculosis was found (1%). In 8% of workers, aged 40--50, a dynamic arterial hypertension and radiological symptoms of aortosclerosis were found. 5% welders had granulocytopenia. Disturbances of the examined systems occurred in factory welders with duration of employment above 10 years.

Adult↗
PubMed1982

A chromosome study among stainless steel welders.

The mutagenicity of welding fumes generated by manual metal arc (MMA) welding of stainless steel (SS) has been shown in several experimental in vitro systems. No data are available on possible chromosome damage among MMA/SS welders. In the present study, structural chromosome aberrations and sister chromatid exchanges (SCEs) were studied in peripheral blood lymphocytes of 23 welders and 22 control subjects. No significant differences in the frequency of chromosome aberrations or SCEs were detected between the two groups. Smokers, both welders and controls, showed a significantly higher SCE rate than non-smokers.

Adult↗
PubMed1981

[Basic studies on ultrasonic surgery. II. Studies on the stability after ultrasonic osteosynthesis in various forms of fractures in vitro].

Investigations on the load capacity of an ultrasonic weld in transverse fractures, oblique fractures, and multiple fragment fractures by means of homologous bone fragments and Fimomed were taken up in vitro on 84 human femur diaphyses. It was possible to demonstrate the essential influence of the form of the fracture on the stability of the weld. The mechanical density was the highest in transverse fractures, small in oblique fractures, and the smallest in multiple fragment fractures. Conclusions were drawn up for the clinical use.

Acrylates↗
PubMed1980

[Study of the relationship between pulmonary changes and blood plasma composition under the effect of industrial dust. III. Usefulness of the results of the studies for diagnostic purposes].

The paper presents results of statistic calculations enabling to define the diagnostic usefulness of results of determining free aminoacids in blood plasma for evaluation of workers' exposure to grinding and ceramic dusts and welding fume. Determination of proline in the blood plasma of ceramic industry workers and electric welders and determination of hydroxyproline in welders' blood plasma were found to be a particularly significant and early index of exposure to ceramic dust or welding fume.

Air Pollutants↗
PubMed1996

[Delayed symptoms of hypoxic brain damage after temporary improvement].

A shipyard worker was doing welding work inside a pipe with argon as cover gas. After taking a break he fainted while controlling the weld, also inside the pipe. He was rescued after 15-20 minutes and regained consciousness after a few hours. Two days later he was discharged from hospital in apparently good health. After a week he returned to the hospital suffering from confusion, failing memory, aphasia, apraxia and urinary incontinence. MR showed elevated signal intensity bilaterally in the caudate nucleus. He improved gradually and six months later was given less demanding work. The course of his illness is consistent with delayed neuropsychiatric sequelae after hypoxia, probably due to displacement of oxygen by argon. Delayed symptoms are caused by demyelination in the subcortical white matter.

Adult↗
PubMed1998

Effects of endogenous absorption in human albumin solder for acute laser wound closure.

BACKGROUND AND OBJECTIVE: Human albumin is currently being used as a biological solder in laser tissue welding. Experiments were performed to characterize the effects of differing albumin concentrations on wound closure when a 1.32 microm Nd:YAG laser is used to repair skin incisions. MATERIALS AND METHODS: In vivo comparison of acute tensile strength was made in full thickness porcine skin wounds using different solder concentrations. Histology of the repairs was also completed to evaluate the thermal denaturation of the tissue and solder. Transmission measurements were completed for nondenatured and denatured albumin solders. Finally, the real time denaturation pattern of different solder concentrations during laser irradiation was investigated. RESULTS: A tissue solder consisting of 50% albumin provides the greatest tensile strength for acute in vivo skin closure. The transmission measurements verify that the primary absorber of 1.32-microm laser light was the solder solvent (water). A significant decrease in power transmission occurs when the 25% albumin solder was denatured. The real time denaturation profiles demonstrate that 1.32-microm laser light denatures 25% albumin solder from the outer surface, while in 50% albumin solder, denaturation occurs from within the solder bulk. Wound histology corroborates the pattern of denaturation seen in vitro. CONCLUSION: The combination of 1.32-microm laser light and 50% human albumin solder can be used to create a deep tissue weld resulting in higher acute repair tensile strength. This permits a deep to superficial closure of wounds, which may result in an optimal method of acute closure for full-thickness wounds.

Animals↗
PubMed1997

Paternal occupational exposure around conception and spina bifida in offspring.

A multi-center case-referent study was conducted on the relation between paternal occupational exposure and spina bifida in offspring. Cases were born between 1980 and 1992 in The Netherlands. Referents were recruited from hospitals and from the general population. Postal questionnaires were used to gather information on occupation and potential confounders. Through job-specific telephone interviews with 122 case fathers and 411 referent fathers, detailed exposure information was collected on specific tasks, the use of chemical or physical agents, frequency of exposure, and use of protective equipment. The study yielded statistically significant associations between spina bifida and low exposure to welding fumes (OR = 1.6, 95% CI: 1.0-2.6) and low exposure to UV radiation during welding (OR = 2.6, 95% CI: 1.2-5.6), and suggestive findings of an association between spina bifida and moderate or high exposure to cleaning agents, moderate or high pesticide exposure (OR = 1.7, 95% CI: 0.7-4.0), and stainless steel dust (OR = 2.0, 95% CI: 0.8-5.2). No associations were identified for other paternal occupational exposures, such as organic solvents.

Case-Control Studies↗