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PubMed1993

[Health status in stainless steel welders].

Health state, as well as hematological, biochemical and cytogenetical changes of 53 stainless steel welders were checked-up. Results were compared to those of non exposed persons (control), and to a group of firemen. Urine metals concentrations correlated with the welding fumes density. In the majority of welders typical complaints appeared: aqueous nasal secretion of a clogged nose feeling. Only some of workers suffered from a metal vapours fever. No changes witnessing the above mentioned risk factors influence on the hematological and biochemical findings were ever proved. Cytogenetical analysis confirmed an increased genetic risk.

Humans↗
PubMed1995

Urinary excretion of chromium as an indicator of exposure to various chromium forms in MMA/SS welders.

Increased levels of Cr discharged with urine after working shift, Cr-U (arithmetic mean 15.8 mu g/g creatinine), and Cr buildup during working shift, DeltaCr-U (arithmetic mean 3.8 mu g/g creatinine), were observed in 15 MMA/SS welders exposed during the working week to welding fumes containing Cr VI (33-56%) - mainly soluble (87%) and Cr III (44-67%) - mainly insoluble (72%). The highest correlation coefficients were obtained for DeltaCr-U vs. Cr total (r = 0.58), Cr VI (r = 0.56) and soluble Cr III in the air. Increased DeltaCr-U value for exposures at MAC Cr VI (16.8 mu g/g creatinine) was demonstrated in welders employed longer than 7 years and exposed to Cr VI below MAC level, which might suggest that the duration of employment affects that value within the low range of concentration of Cr VI in the air (< 0.03 mg/m3). Nevertheless, linear relationship between DeltaCr-U for exposures to Cr VI at MAC levels and duration of employment was not confirmed for wide range of air Cr VI (0.005-0.4 mg/m3). Similar DeltaCr-U values at MAC for Cr VI (6.4 and 6.6 mu g/g creatinine) were obtained for all welders, and those employed over 7 years, respectively, which may suggest that this parameter can be misleading.

Adult↗
PubMed1996

[Identification of inhaled dust with a noninvasive magnetometry method].

The authors performed an examination of the degree of lung contamination by magnetic compounds present in gases originating during welding in 33 persons divided into four groups. The measurement was performed by a noninvasive magnetometric method using a high sensitive SQUID and second degree gradiometric antenna with presumed maximum sensitivity of 60 micrograms of magnetic compound/cm3. In the selected three groups of welders working for a long period of time under the conditions of exposure, the changes of the magnetic field were particularly evident in the group working in small confined spaces. It has become obvious that further improvement in the accuracy of the detected results in the lung may be reached in the subjects by changing the polarity of magnetization. (Fig. 4, Ref. 13.).

Adult↗
PubMed1997

Angular and fibrous particles in lung are markers of job categories.

INTRODUCTION: The lung concentration of angular and fibrous particles has been measured when cases are stratified into their job categories; 21 miners (metallic mines such as gold, zinc and copper), 18 iron foundrymen, 22 non-iron foundrymen, four welders, three sand-blast workers, four construction workers, three technicians and professionals, seven workers in other trades excluding welding. Twelve asbestos miners representing a positive exposure to asbestos and 20 people representing a background population were added to the previous groups. MATERIAL AND METHODS: Particles, both angular and fibrous, were extracted from lung parenchyma by a bleach digestion method, mounted on copper microscopic grids by a carbon replica technique and analyzed by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). Quartz concentration was also determined by X-ray diffraction (XRD) on a silver membrane filter after the extraction from the lung parenchyma. RESULTS: (1) The highest concentrations of quartz were found in mines (metallic mines), iron foundrymen and sand-blast workers. Notable amounts quartz were found in welders and professionals. (2) The highest concentrations of short fibres were found in non-iron foundrymen, asbestos miners and construction workers. (3) The highest concentrations of long fibres were found in non-iron foundry men and asbestos miners. (4) The highest concentrations of ferruginous bodies were found in non-iron foundrymen and asbestos miners. (5) The non-iron foundrymen were exposed to ceramic fibres and asbestos fibres. CONCLUSION: The results of the study may not be representative of the broad spectrum of workers in the industrial activities in which they have been involved. However, the detailed composition of the retained particles of our workers is explained both qualitatively and quantitatively by their work histories. Finally, the broad range of particle types identified in the lungs of these workers illustrate the complexity or trying to determine disease origins in these occupational settings.

Biological Availability↗
PubMed1997

[Frequency of sister chromatid exchanges (SCE)in peripheral blood lymphocytes from stainless steel welders].

In order to detect the genotoxic effects of nickel (Ni) and chromium (Cr) contained in welding fumes on humans, sister chromatid exchanges (SCEs) frequency in lymphocytes was determined in the blood samples derived from 39 stainless steel welders and compared with the data obtained from 22 sex and age matched unexposed controls. The frequency of SCEs was higher in the welders than in the controls. Smoking proved to be a significant, positive predictor for SCE frequency in the controls but not in the welders. Significant correlation between SCE and chromium concentrations in urine of smoking welders was found. A possible synergism between chromium exposure and smoking is discussed. Neither age and urine nickel concentrations nor duration of exposure was a significant predictor for SCE frequency.

Adult↗
PubMed1998

Long-term monitoring of the immune reactivity of stainless steel welders.

The immune reactivity of stainless steel welders (n = 22-53) was evaluated in a three year's study. The results (phagocytic activity, cellular and humoral immunity) were statistically compared with those in control group of non-exposed persons from the same plant (n = 14-23) and with long-term laboratory reference values (LRV) (n = 14-311). In welders several changes were found when compared to the LRV: in humoral response there were higher prealbumin, lysozyme, circulating immune complexes and lower IgG. In phagocytic tests there were lower ingestion, bactericidal activity and higher metabolic activity of peripheral mononuclear leucocytes. In cellular immunity the marked lymphocytosis, higher counts of T-lymphocytes, CD4+ and CD8+ lymphocytes were noticed. After lowering the concentrations of metals in the working area there were trends to normal values in some parameters [relative numbers of T-lymphocytes, relative number of CD4+ lymphocytes, phagocytic activity, metabolic activity of leucocytes (INT index), IgA, complement C3, transferrin]. The extent and the length of the exposure to welding fumes, smoking and changed conditions at working place were followed as well.

Adult↗
PubMed1998

Metal fume fever.

Metal fume fever (MFF) is an acute self-limited, flu-like illness resulting from inhalation of metal oxides. Despite the well-documented history of MFF in the medical literature, the illness may remain unrecognized because it may mimic a viral illness. The case of a patient with MFF due to galvanized steel welding presenting to the emergency room is described.

Adult↗
PubMed1988

Multiple sclerosis, solvents, and pets. A case-referent study.

The effect of potential risk factors for multiple sclerosis was evaluated in a case-referent study that encompassed 83 cases and 467 randomized referents. Information on exposure was obtained by questionnaires that were mailed to the subjects. Mantel-Haenszel rate ratios were increased for males for occupational exposure to solvents and welding and for females for leisure time contact with dogs and caged birds. For both sexes, x-ray film examination occurred more frequently among cases than referents, possibly as an effect of early symptoms from the disease itself.

Adult↗
PubMed1979

Argon laser in human tympanoplasty.

We describe the use of an argon laser in human tympanoplasty. The laser was used in two different ways: (1) to stop the bleeding of small vessels in the external auditory channel and eardrum remains; and (2) to spot-weld the new eardrum graft in the proper position. Seven operations were performed. We report the results.

Animals↗
PubMed1990

Initial trial of argon ion laser endarterectomy for peripheral vascular disease.

In the initial of open laser endarterectomy, 16 patients underwent 18 reconstructions for claudication (13 patients), rest pain (3 patients), and gangrene (2 patients). The mean (+/- SD) preoperative ankle arm index was 0.53 +/- 0.18. The laser endarterectomies were aorto-bi-iliac (1 patient), iliac (1 patient), superficial femoral (7 patients), profunda femoral (7 patients), and popliteal-posterior tibial (2 patients). All operations included surgical exposure, vascular control, administration of heparin, and an arteriotomy. Atheromas were dissected from arteries with argon ion laser radiation (power, 1.0 W). End points were welded with laser light. Arteries were closed primarily. The laser endarterectomies were 6 to 60 cm long and required 168 J to 2447.5 J. All patients had symptomatic relief, with a postoperative ankle arm index of 0.97 +/- 0.10. There were no arterial perforations from laser radiation. Surgical complications included early thrombosis requiring thrombectomy (3 patients) and hematoma requiring evacuation (1 patient). The laser endarterectomies have an 88% patency at 1 year. Open endarterectomy can be performed with laser radiation. A larger clinical trial is necessary to define the indications for laser endarterectomy in peripheral vascular disease.

Adult↗
PubMed1998

Clinical research: perceptions, reality, and proposed solutions. National Institutes of Health Director's Panel on Clinical Research.

CONTEXT: The proportion of investigators applying for clinical research grants from the National Institutes of Health (NIH) who are physicians has declined from 40% 30 years ago to 25% today. OBJECTIVE: To recommend NIH policy changes that might encourage physician investigators to undertake careers in clinical research, eg, patient-oriented research, epidemiologic and behavioral studies, outcomes research, and health services research. PARTICIPANTS: The NIH Director's Panel on Clinical Research comprised 14 physicians from academia and industry, chosen by the director. They met in numerous closed sessions and in 5 public meetings from July 1995 to November 1997. CONSENSUS PROCESS: In addition to expert opinion and pertinent literature, data sources included the training characteristics of applicants to NIH who were funded or not. Topics considered included financing of clinical research, recruitment, training, and retention of future clinical investigators, conduct of clinical trials, and peer review of clinical research. Consensus was reached and recommendations were made in response to an interim report, widely circulated to the biomedical community, written by members of the panel, which contained preliminary recommendations. CONCLUSIONS: The panel's final recommendations to NIH included maintaining at least the present proportion of NIH funding for clinical research; continuing mentored opportunities in clinical research for medical students; promoting clinical research training by offering didactic courses and grant opportunities in clinical research to nascent investigators emerging from specialty training programs and providing partial salary support for mentors; restructuring study sections that review patient-oriented research applications to include more physicians; encouraging clinical investigators and basic scientists to work closely together and weld collaborations between academic clinical investigators and colleagues in pharmaceutical and biotechnology companies; and developing a joint policy between academic health centers and NIH for the support of clinical research and clinical research training.

Budgets↗
PubMed1996

Effect of the CO2 milliwatt laser on neuroma formation in rats.

BACKGROUND AND OBJECTIVE: The purpose of this study was to determine whether the milliwatt laser can suppress neuroma formation at the end of a divided nerve. STUDY DESIGN/MATERIALS AND METHODS: The peripheral nerves of eight rats were transected with microscissors and the cross-sectional area of their proximal ends was irradiated using the CO2 milliwatt laser. The power ranges used were similar to those applied to weld neural tissue. RESULTS: None of the eight irradiated nerve ends formed a neuromatous bulb and only one of them regenerated into the surrounding tissues. Histologically, these nerve ends did not show the disorganized picture of classic neuromas. On morphometric measurements, they contained less connective tissue than the control nerve ends (P < 0.001) and their nerve fibers were larger in diameter (P < 0.001) and better myelinated (P < 0.001). CONCLUSION: These findings in rats show that the CO2 milliwatt laser has the ability to suppress neuroma formation at the end of a divided nerve.

Animals↗
PubMed1997

Effect of the CO2 milliwatt laser on tensile strength of microsutures.

BACKGROUND AND OBJECTIVE: Laser-assisted tissue repair is often accompanied by a high dehiscence rate, which may be due to alterations in suture material after laser exposure. The goal of this study was to investigate the effect of CO2 laser irradiation on the tensile strength of microsurgical suture material. STUDY DESIGN/MATERIALS AND METHODS: 10-0 nylon and 25 microns stainless steel threads were exposed to 12 combinations of power densities (62, 124, and 186 W/cm2) and pulse durations (0.5, 1, 2, 3 s) and tested on a tensometer for their tensile strength. RESULTS: At power densities of 186 W/cm2, the 10-0 nylon thread disrupted during laser irradiation, regardless of pulse duration. This was also the case at power densities of 124 C/cm2 for 2 s and 3 s pulse duration. At 124 W/cm2 for 0.5 and 1 s, the tensile strength decreased with 70% relative to the control. At 62 W/cm2, the tensile strength gradually decreased from 100% (0.5 s pulse duration) to 50% (3 s pulse duration) relative to control. Stainless steel thread resisted all laser irradiations. CONCLUSIONS: The 10-0 nylon thread is significantly compromised by irradiation with the CO2 milliwatt laser and therefore meticulous care should be taken not be irradiate the sutures during laser tissue welding.

In Vitro Techniques↗
PubMed1997

Laser-activated solid protein bands for peripheral nerve repair: an vivo study.

BACKGROUND AND OBJECTIVE: Severed tibial nerves in rats were repaired using a novel technique, utilizing a semiconductor diode-laser-activated protein solder applied longitudinally across the join. Welding was produced by selective laser denaturation of solid solder bands containing the dye indocyanine green. STUDY DESIGN/MATERIALS AND METHODS: An in vivo study, using 48 adult male Wistar rats, compared conventional microsuture-repaired tibial nerves with laser solder-repaired nerves. Nerve repairs were characterised immediately after surgery and after 3 months. RESULTS: Successful regeneration with average compound muscle action potentials of 2.5 +/- 0.5 mV and 2.7 +/- 0.3 mV (mean and standard deviation) was demonstrated for the laser-soldered nerves and the sutured nerves, respectively. Histopathology confirmed comparable regeneration of axons in laser- and suture-operated nerves. CONCLUSION: The laser-based nerve repair technique was easier and faster than microsuture repair, minimising manipulation damage to the nerve.

Action Potentials↗
PubMed1997

Proportionate mortality among unionized construction ironworkers.

This report presents the results of proportionate mortality ratios (PMR) and proportionate cancer mortality ratios (PCMR) among 13,301 members of the International Union of Bridge, Structural, and Ornamental Ironworkers who had been members for a minimum of 1 year, were actively paying dues into the death beneficiary fund, and had died between 1984-1991. Using the United States proportionate mortality rates as the comparison population, statistically significant elevated risks, using 95% confidence intervals (CI), were observed for several types of injuries: falls (N = 259, PMR = 3.57, CI = 3.15-4.03), transportation injuries (N = 363, PMR = 1.22, CI = 1.10-1.35), and other types of injuries (N = 225, PMR = 1.63, CI = 1.43-1.86). The deaths due to falls were significantly elevated for each 10-year age group under age 60 (PMR > 7.00) and for those workers with < 20 years in the union (PMR > 6.00). Elevated mortality risks were also observed for all malignant neoplasms combined (N = 3,682, PMR = 1.09, CI = 1.06-1.13) as well as for site-specific malignant neoplasms of the lung (N = 1,523, PMR = 1.28, CI = 1.21-1.35), pleural mesothelioma (N = 7, PMR = 1.67, CI = 0.67-3.44) and "other and unspecified sites" (N = 307, PMR = 1.29, CI = 1.15-1.44). The category "pneumoconiosis and other respiratory diseases" was also significantly elevated (N = 690, PMR = 1.11, CI = 1.03-1.20); in this category, deaths due to asbestosis had the greatest elevated risk (N = 10, PMR = 3.56, CI = 1.70-6.54). No elevation in risk was found for kidney cancer or for chronic nephritis which were of interest because of Ironworkers' potential exposure to lead. The present study underscores the importance of fall protection and other injury prevention efforts in the construction industry, as well as the need to control airborne exposures to asbestos, welding fumes and other respirable disease hazards.

Accidents, Occupational↗
PubMed1997

Lead levels in Maryland construction workers.

A cross-sectional study of unionized construction workers not currently known to be performing lead work was conducted. Participants completed an interviewer-administered questionnaire obtaining information about demographics, work history, other possible sources of lead exposure and health status (including hypertension, noise-induced hearing loss and renal disease). Blood was then obtained via venipuncture for whole blood lead level, hematocrit and free erythrocyte protoporphyrin determination. Two hundred and sixty-four Maryland construction workers had median whole blood lead determinations of 7 micrograms/dl and mean values of 8.0 micrograms/dl, with a skewed distribution ranging from 2 to 30 micrograms/dl. None were currently engaged in known lead work. Blood lead levels were significantly higher for the 124 who had 'ever' worked in demolition (8.8 micrograms/dl vs. 7.2 micrograms/dl, p = .004), and for the 79 who had ever burned paint and metal and welded on outdoor structures compared to the 48 who had done none of these activities (8.6 micrograms/dl vs. 6.8 micrograms/dl, p = .01). The 58 workers who had ever had workplace lead monitoring performed had higher lead levels (9.7 vs. 7.5 micrograms/dl, p = .003). Blood lead levels increased with age, and cigarette smoking. African Americans (N = 68) had higher lead levels (9.1 vs. 7.5 micrograms/dl, p = .01). There were only two women in the study, one with a lead level of 21 micrograms/dl and one, 7 micrograms/dl. Blood lead levels did not predict either systolic or diastolic blood pressure in this population. However, there was a significant interaction between race and lead as predictors of blood pressure, with blacks demonstrating a trend-significant correlation, and whites showing a nonsignificant but negative association. Demolition and hotwork on outdoor structures are known to cause acute episodes of lead poisoning. They also appear to cause slight but persistent increases in blood lead levels. Future workplace regulation should recognize and seek to maintain the low baseline now apparent even in urban, East Coast, construction workers.

Adolescent↗
PubMed1997

Proportionate mortality among unionized construction operating engineers.

This report presents the results of proportionate mortality ratios (PMR) and proportionate cancer mortality ratios (PCMR) among 15,843 members of the International Union of Operating Engineers who had died between 1988-1993. Operating engineers represent one of the 15 unions in the Building and Construction Trades Department and are responsible for the operation and maintenance of heavy earthmoving equipment used in the construction of buildings, bridges, roads, and other facilities. Using U.S. proportionate cancer mortality as the referent, statistically significant elevated mortality was observed for cancers of the lung (PCMR = 1.14, 95% confidence interval (CI) = 1.09-1.19) and bone (PCMR = 2.14, CI = 1.19-3.52). Using U.S. proportionate mortality as the referent, statistically significant elevated mortality was observed for other benign and unspecified neoplasms (PMR = 1.54, CI = 1.09-2.13), emphysema (PMR = 1.37, CI = 1.20-1.55), other injuries (PMR = 1.43, CI = 1.20-1.70) (which included crushing under/in machinery, tractor rollover, run over by crane), and suicide (PMR = 1.22, CI = 1.06-1.40). The PMR for leukemia, and aleukemia (PMR = 1.19, CI = 1.02-1.37), but not the PCMR (1.07, CI = 0.92-1.24), was also significantly elevated. Some of the occupational exposures that may have contributed to these excesses include diesel exhaust, asphalt and welding fumes, silica dust, ionizing radiation, and coal tar pitch. The present study underscores the need to control airborne exposures to these substances and for injury prevention efforts aimed at operating engineers in the construction industry.

Accidents, Occupational↗
PubMed1998

Lung health among boilermakers in Edmonton, Alberta.

BACKGROUND: Construction boilermakers may be exposed to a variety of substances, including asbestos and welding fumes. Past studies of boilermakers have shown increases in mortality from lung cancer and asbestosis and radiographic changes consistent with asbestos exposure. METHODS: Respiratory symptoms, lung function, and radiographic changes were compared for 102 actively employed boilermakers with 20 or more years of union membership and 100 telephone workers. Posteroanterior chest radiographs were evaluated by two experienced chest physicians, with a third arbitrating disagreed films. Union members were further categorized as boilermakers (n = 50) or welders (n = 52), based on longest service. Lung health was also compared with employment in a number of work sectors for time, and time-weighted exposure to dust and fumes. RESULTS: Boilermakers had more respiratory symptoms than telephone workers, but lung function did not differ. Radiographic changes were more common among the boilermakers (20% with any change, 8% circumscribed, and 9% diffuse pleural thickening). None of the boilermakers had small radiographic opacities. Several symptoms suggestive of bronchial responsiveness were associated with fume exposures in the gas and oil industry. Workers whose longest service was as a boilermaker demonstrated more symptoms than did welders. FEV1, FEV1/FVC, FEF25-75, and FEF50 were significantly lower among boilermakers compared with welders. CONCLUSION: Health screening programs for these workers are warranted.

Adult↗