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PubMed1999

Sutureless microvascular anastomoses by a biodegradable laser-activated solid protein solder.

A new sutureless technique to successfully anastomose the abdominal aorta of rats (1.3 mm in diameter) by using a fully biodegradable, laser-activated protein solder is presented. A total of 90 rats were divided into two groups randomly. In group one, the anastomoses were performed by using conventional microsuturing technique, whereas in group two, the anastomoses were performed by using a new laser welding technique. In addition, each of the two groups were divided into five subgroups and evaluated at different follow-up periods (10 minutes, 1 hour, 1 day, 1 week, and 6 weeks). At these intervals, the anastomoses were evaluated for patency and tensile strength. Three anastomoses in each subgroup were processed for light and electron microscopy. All anastomoses were found to be patent. The mean clamp time of the anastomoses performed with conventional suturing was 20.6 minutes compared with 7.2 minutes for the laser-activated welded anastomoses (p < 0.001). The strain measurements showed a stronger mechanical bond of the sutured anastomoses in the initial phase. However, at 6 weeks the tensile strength of the laser-welded anastomoses was higher compared with the conventional suture technique. Histologic evaluations revealed a near complete resorption of the solder after 6 weeks. The junction site of the vessel ends cannot be determined on the luminal side of the artery. In conclusion, a resorbable protein used as a solder, activated by a diode laser, can provide a reliable, safe, and rapid arterial anastomosis, which could be performed by any microsurgeon faster than conventional suturing after a short learning curve.

Anastomosis, Surgical↗
PubMed1996

Airway reactivity in welders: a controlled prospective cohort study.

In a 3-year survey, respiratory symptoms, spirometry, and methacholine reactivity were measured annually in welders (n = 51) and non-welder controls subjects (n = 54) to determine whether welding-related symptoms are associated with accelerated decline in lung function or changes in airway reactivity. In the cross-workshift study, maximal midexpiratory flow rate declined reversibly during a welding day, whereas 1-second forced expiratory volume and forced-vital capacity were unchanged. In the longitudinal study, the welders had significantly more reversible work-related symptoms of cough, phlegm, wheeze, and chest tightness than the non-welder shipyard control subjects. In this group of actively working welders, across-workshift changes in midflow and reversible symptoms were related to the welding occupation, but evidence for chronic irreversible effects on spirometry or airway reactivity was not seen over the 3 years of observation. The short period of observation was not optimal for detecting a chronic effect on lung function. Work practices and engineering controls may be successfully preventing irreversible respiratory effects, but not mild reversible effects, in this group of welders.

Adult↗
PubMed2000

Incidence of cancer among welders and other shipyard workers with information on previous work history.

The incidence of cancer among 4480 shipyard workers, including 861 welders, was investigated for a potential relationship between exposure to welding fumes and lung cancer. A subcohort of 3150 workers with information on previous work history was studied separately. This investigation is a historical prospective cohort study. Environmental air samples were collected in 1973, 1977, and 1989. Information on smoking habits was surveyed in 1976 and 1984. The employment work histories were collected from the personnel register. There were 411 observed cancers of all sites versus 387.5 expected, and 45 cases of lung cancer versus 51.3 expected. Nine cases of lung cancer were found among the welders versus 7.1 expected. Among 310 former seamen with welding experience, there was 1 case of lung cancer versus 2.1 expected. These shipyard workers showed no excess risk of lung cancer. Tobacco smoking and asbestos exposure are potential confounders in the study. There was no clear relationship between exposure to welding fumes and lung cancer, but welders with the longest experience had a relative risk of 1.9 for lung cancer. The differences in lung cancer incidence among the different shipyard workers could not be attributed to differences in recruitment patterns or previous work history.

Adolescent↗
PubMed2005

A cohort study of Parkinson's disease and other neurodegenerative disorders in Danish welders.

OBJECTIVE: We sought to evaluate rates of hospitalizations for neurodegenerative disorders in a cohort of Danish metal manufacturing employees. METHODS: A retrospective cohort study was conducted from 1977 to 2002 among 27,839 male Danish metal-manufacturing employees, with 9,817 of those employed in departments engaged in mild or stainless-steel welding and 6,163 welders. RESULTS: The standardized hospitalization ratio and 95% confidence intervals (CI) for Parkinson's disease were 0.9 (CI = 0.7-1.2) for men in steel-manufacturing companies, 1.0 (CI = 0.7-1.5) for men in welding departments, and 0.9 (CI = 0.4-1.5) for welders. Observed numbers for other neurological conditions were small and not above population expectations. Analyses for time period worked, age, and duration of welding were unremarkable. CONCLUSIONS: This relatively large cohort study with long-term follow-up provides no support for the hypothesis that rates of hospitalization for Parkinson's disease or other neurological conditions are elevated under the exposure circumstances of these Danish workers.

Adult↗
PubMed2005

Welder's lung associated with pneumothorax.

A 23-year-old male working in welding for 8 years was admitted to the hospital with chest pain. A large right pneumothorax with complete lung collapse was seen radiographically and a tube thoracostomy performed. At high-resolution computed tomography, multiple bilateral well-marginated nodules with surrounding ground-glass opacity were seen. Welder's lung was considered in this patient because of his work in welding for 8 years with iron dust exposure, multiple nodules with ground-glass opacity were seen on HRCT, and serum ferritin and ferritin levels in bronchoalveolar lavage fluid were elevated. The granules in alveolar macrophages obtained from parenchymal biopsy and bronchoalveolar lavage stained strongly with iron dyes. Following avoiding exposure to welding fumes, the lung lesions disappeared without additional therapeutic interventions after a 3-week period. Welder's lung with associated lung lesions has been described, although complicating pneumothorax is unique to the case presented herein.

Adult↗
PubMed2006

Neuropsychological profiles of manganese neurotoxicity.

The etiology of manganese neurotoxicity is heterogenous and includes exposure to welding fumes, chronic liver failure, and chronic total parental nutrition (TPN). We recently reported that cognitive impairment occurs in welders and patients with chronic liver failure who had evidence of manganese neurotoxicity including abnormal magnetic resonance imaging (MRI) basal ganglia T1 hyperintensity. In this study, we compared the neuropsychological profiles of patients with manganese neurotoxicity and basal ganglia T1 hyperintensities from three different etiologies: welding, chronic liver failure, and chronic TPN. Across all three groups, the neuropsychological profiles suggest frontal and subcortical cognitive impairment, with more widespread abnormalities occurring in the non-welding groups.

Adult↗
PubMed1986

Influence of submerged electrical welding/cutting on dental amalgam in Swedish divers.

Professional commercial divers working with electrical cutting and welding sometimes experience a metallic taste phenomenon. An enquéte study among divers showed no influence of different equipment on the occurrence of such metallic taste, but it seems to occur less frequently in low salinity water. It has been suggested that this metallic taste phenomenon is due to increased corrosion rate of dental restorations, especially of amalgam. Experimental results recording the potential of amalgam specimens placed in the oral cavity of divers during welding, showed influence on the potential, and thus probably on the corrosion rate, during welding only when the diver came into direct contact with the water, e.g. through leakage in the suit.

Adult↗
PubMed1979

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

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.

Adult↗
PubMed1981

Non-invasive magnetopneumographic determination of lung dust loads in steel arc welders.

Magnetopneumography was used to measure non-invasively the concentration of the ferrimagnetic fraction of retained welding fume in the thoraces of steel arc welders. This was done by measuring the remanent magnetic fields due to ferrimagnetic particles. The 11 welders studied had concentrations of thoracic ferrimagnetic mineral several orders of magnitude greater than three machinists, 16 former asbestos insulators and 24 control subjects. These concentrations correlated well with total years welding (p less than 0.01) and radiographic evidence of small rounded densities (p less than 0.05), but not with smoking history. There was a higher concentration of ferrimagnetic mineral over the hilar regions. Magnetopneumography offers a non-invasive indicator of the accumulation of welding fume in the thorax.

Adult↗
PubMed1992

Semen quality in welders exposed to radiant heat.

Several studies suggest that welding is detrimental to the male reproductive system. Welding fume and radiant heat are of interest as possible causal factors. This study investigates semen quality and sex hormone concentrations among 17 manual metal arc alloyed steel welders with a moderate exposure to radiant heat (globe temperature ranging from 31.1 degrees to 44.8 degrees C), but without substantial exposure to welding fume toxicants. During exposure to heat the skin temperature in the groin increased on average by 1.4 degrees C (SE +/- 0.72 degrees C). Sperm count and motile sperm count were non-significantly reduced among welders in comparison with two different reference groups. Within the group of welders the proportion of sperm with normal shape declined significantly after six weeks of exposure to heat and increased after a break in exposure. Sperm count and sperm concentration had the same pattern of intraindividual change in relation to exposure to radiant heat, but the changes were not statistically significant. No consistent changes in concentrations of sex hormones were found. The welders investigated were more exposed to radiant heat than welders in general. The results suggest that the study group of welders experienced a reversible decrease in semen quality, most likely caused by a moderate exposure to radiant heat (about five hours a day through several weeks). It remains to be established if even lower levels of exposure to radiant heat in the general population of welders has any impact on semen quality and fertility.

Adult↗
PubMed1994

Transient changes in the pulmonary function of welders: a cross sectional study of Monday peak expiratory flow.

OBJECTIVES: The aim was to compare the peak expiratory flow (PEF) of welders and non-welders over a 12 hour period from the start of work on Monday. METHODS: The two study groups consisted of 20 welders and 20 non-welders, all men who had essentially never smoked, with no significant difference in age, height, ethnicity, or baseline spirometry between the groups. The PEF was measured for each welder before the start of work and 15 minutes, 30 minutes, and 1, 2, 4, 7, and 12 hours after the start of welding. The same method was applied to the non-welders, for whom a proxy time for the start of welding was used. RESULTS: The percentage change in baseline PEF was calculated for each subject at each of the recording times. The welder and non-welder group means for these results were significantly different at 15 minutes (p = 0.028). Also, the group mean for maximum fall in PEF (at any of the recording times during the 12 hour period) was significantly greater for the welders (p = 0.011). 50% of the welders (10/20), but only 5% of the non-welders (1/20), experienced a fall in PEF in excess of 5% (p = 0.0046). 25% of the welders (5/20) experienced drops of greater than 5% within the first 15 minutes. CONCLUSION: The results are suggestive of an immediate type reaction in welders, similar to that seen in some cases of occupational asthma, although not so severe. Studies to determine if these reactions reflect non-specific bronchial hyper-responsiveness would be useful. It is recommended that future studies also undertake breathing zone measurements to relate the response to particular constituents of the welding plume, especially the gases ozone and nitrogen dioxide.

Adult↗
PubMed1999

Two year follow up of pulmonary function values among welders in New Zealand.

OBJECTIVES: To examine whether welding is a risk factor for an accelerated decline in pulmonary function. METHODS: 2 Year follow up of pulmonary function and respiratory symptoms among 54 welders and 38 non-welders in eight New Zealand welding sites. RESULTS: There were no significant differences in age, height, smoking habits, ethnicity, or total time in industrial work between welders and non-welders. No overall differences were noted in the changes of pulmonary function variables between the two study groups. However, when the comparison was restricted to smokers, welders had a significantly greater (p = 0.02) annual decline (88.8 ml) in FEV1 than non-welders, who had a slight non-significant annual increase (34.2 ml). Also, welders without respiratory protection or local exhaust ventilation while welding had a greater annual decline both in forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) than welders with protection (p = 0.001 and 0.04, respectively). Among welders a significant association was found between the acute across shift change and the annual decline in FEV1. Chronic bronchitis was more common among welders (24%) than non-welders (5%). Only one welder (2%) but eight non-welders (21%) reported having asthma. CONCLUSIONS: Welders who smoked and welders working without local exhaust ventilation or respiratory protection have an increased risk of accelerated decline in FEV1.

Adult↗
PubMed1981

Process-dependent risk of delayed health effects for welders.

In most industrialized countries large numbers of workers are exposed to welding fumes. Although the general pattern of welders' health may not significantly differ from that of workers in other dusty industrial occupations which demonstrate elevated incidence of respiratory tract diseases with long latency periods, the extremely wide range of substances at potentially high concentrations produced by various welding technologies may give rise to undetected process-specific high-risk working conditions: ("hot spots"). The origin, prevalence and range of magnitude of such hot spots, especially for cancer of the respiratory tract, is discussed, with emphasis placed on the assessment of risk resulting from exposure to Cr(VI) and Ni accompanying the use of various technologies for the welding of stainless and high alloy steels. The wide variation of health effects found within the industry, however, indicates the need for a standard protocol for future epidemiological studies, as well as for the development of suitable methodologies for experimental risk assessment.

Air Pollutants↗
PubMed1981

[Pulmonary functions observed by means of flow-volume curve in welders exposed to ozone (author's transl)].

Pulmonary functions were observed by the flow-volume curve method on 68 healthy welders who had been exposed to comparatively high levels of ozone while engaged in arc welding process shielded by inert gas. The welders between 20 and 29 years of age were selected as subjects and classified into five groups according to ozone concentrations of the workshops. Results of pulmonary function tests were analyzed with reference to working experiences, dust concentrations of the workshops, smoking habits and air pollution levels of the location of factories. An attempt were made to evaluate the possible effects of prolonged exposure to ozone produced by welding upon the health or workers. The results obtained were as follows. 1. Values of both peak flow rate and maximum expiratory flow rate at 75% of vital capacity (V75) were decreased slightly in welder groups, but relationships between the observed values and ozone concentrations were not recognized. 2. Values of maximum expiratory flow rate at 25% of vital capacity (V25) of welders who had been exposed to ozone in concentration of 1.05 ppm or more were decreased significantly compared with groups exposed to ozone under 1.05 ppm. 3. In addition, values of both V25 and forced vital capacity (FVC) of the workers who had been engaged in welding for 4 years or more were significantly lower than those of the workers for less than 4 years of exposure. However, the relationship between the lung function values and smoking habits were not significant in both groups. 4. The decreases in V25 values were observed in several workers who had been exposed even to 0.46 ppm or higher (but under 1.05 ppm) ozone concentrations. 5. Relationships between the lung function values and either smoking habits or air pollutant levels of locations were not significant in all groups.

Adult↗
PubMed2001

Pulmonary functions in ARC-welders in Ile-Ife, Nigeria.

OBJECTIVE: To investigate the occupational effects of Arc-welding on small scale welders in Modakeke, Ile-Ife, Nigeria. DESIGN: A community-based, cross-sectional study. SETTING: A semi-urban area Modakeke, Ile-Ife, Nigeria. POPULATION: A semi-urban area with a population of about 300,000 (three hundred thousand). STUDY POPULATION: Forty four Arc-welders in Modakeke, Ile-Ife and fifty age and sex-matched controls working in the Maintenance Department of Obafemi Awolowo University, Ile-Ife, Nigeria. INTERVENTION: Structured questionnaires adapted from the Medical Research Council, UK respiratory questionnaire with some modifications were administered to all subjects and controls. Physical examination and lung function tests were also carried out on all subjects and controls. MAIN OUTCOME MEASURES: Occupational-related symptoms of welders and controls were compared. Ventilatory function of welders and controls were also compared using the Student's 't'-test. Chi-square was adopted to test the strength of relationship between smoking and lung function abnormalities. RESULTS: The most frequent symptoms found among the subjects were eye irritation (95.43%), rhinitis (50.09%) and skin irritation (43.19%). The arc-welders were found to have characteristically lower lung function parameters than controls (p < 0.05). Ten (22.7%) of the subjects had obstructive lung disease compared to four (8%) of the controls; while 18 (40.9%) of the subjects had restrictive lung disease. Their lung abnormalities had no relationship to their smoking history. CONCLUSION: Workers exposed to arc-welding are at risk of occupational-related symptoms and chronic lung disease. Adoption of protective devices and monitoring of welders' breathing zones for toxic levels of gases and fumes are necessary to reduce the risk associated with arc-welding.

Adolescent↗
PubMed1987

Mortality in two cohorts of welders exposed to high- and low-levels of hexavalent chromium.

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. A cohort consisting of 234 welders working on stainless steel and exposed to high levels of chromium was selected. According to an earlier survey the hexavalent chromium exposure of such welders was often above 20 micrograms/m3. Another cohort consisting of 208 railway track welders exposed to low levels of chromium was also selected. The participants of both cohorts had welded for at least five years some time between 1950 and 1965 and were followed for mortality until December 1984. Among the welders exposed to high chromium levels five deaths occurred due to pulmonary tumors. This number is significantly greater than the one death that occurred among the welders exposed to low levels of chromium, but not significantly greater than the corresponding mortality of the general population. Thus exposure to stainless steel welding fumes might be associated with an increased incidence of pulmonary tumors.

Chromium↗
PubMed1999

[Health status of persons occupationally exposed to chromium, nickel, manganese and polycyclic aromatic hydrocarbons].

Occupational environment monitoring and biological-medical monitoring of persons professionally exposed to welding fumes have been performed. Chromium, manganese and polycyclic aromatic hydrocarbons in welding fumes represents an important health risk. Pollutant concentrations found in metal welding fumes represented only fractions of those acceptable ones. Polycyclic aromatic hydrocarbons have been reached the concentration found in a busy road crossing in Hradec Králové (compared with these as in Czech Republic no maximum acceptable levels for PAHs having been declared). Family, personal and occupational history have been taken. Health state including total haematological count, biochemical and cytogenetical changes of 19 stainless steel welders were checked-up. The level of mercapturates in urine were examined as well. The data were statistically compared with those of non exposed (control group). No changes witnessing the above mentioned risk factors influence on the haematological, biochemical and cytogenetical findings were ever proved. In conclusion, our results did not confirm an increased professional risk in this group of welders.

Adult↗
PubMed1999

[Biological monitoring of occupational exposure in welders of stainless steel. Immunologic methods].

Biological monitoring of occupational exposure to toxic compounds enables an early detection of adverse health effects. Apart from the standard biological monitoring methods of occupational exposure represented by metabolites and enzymes activities analysis also immunological detection methods seem to be promising. The changes of immunological system are demonstrable extraordinary sensitive markers of load of organism. The process of welding belongs between important sources of pollution of working environment with heavy metals and other harmful compounds including polycyclic aromatic hydrocarbons. According to IARC classification the welding fumes are included into group 2B and are supposed as possible human carcinogens. Numbers of different epidemiological studies have proved relationship between welding and serious health disorders namely malignancies. We recorded a number of changes in immunological parameters when compared with those in control group in our study. The results of analysis were statistically evaluated. The statistically significant reduction of number of phagocytosis capable cells was found in the group of welders when compared with the control group. The levels of neopterin, beta-2-microglobulin and IL-1 beta have indirectly monitored cell component of immunological response. In the case of these markers a statistically significant increases were found in the group of welders. We found statistically significant IgM decrease and statistically significant IgA increase in humoral responses with the same group when compared with control group.

Adult↗