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PubMed1976

[Photocoagulation: a microsurgical welding method for ophthamology].

The author describes first of all the history of photocoagulation from its very beginning up to the most recent instruments. Then examples are given of the different possibilities of application. Besides the detachment of the retina and the tumors, the diseases of the vessels of the retina are playing an important role.

Diabetic Retinopathy↗
PubMed1976

Welded hair.

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Detergents↗
PubMed1997

Exposure of welders and other metal workers to ELF magnetic fields.

This study assessed exposure to extremely low frequency (ELF) magnetic fields of welders and other metal workers and compared exposure from different welding processes. Exposure to ELF magnetic fields was measured for 50 workers selected from a nationwide cohort of metal workers and 15 nonrandomly selected full-time welders in a shipyard. The measurements were carried out with personal exposure meters during 3 days of work for the metal workers and I day of work for the shipyard welders. To record a large dynamic range of ELF magnetic field values, the measurements were carried out with "high/low" pairs of personal exposure meters. Additional measurements of static magnetic fields at fixed positions close to welding installations were done with a Hall-effect fluxmeter. The total time of measurement was 1273 hours. The metal workers reported welding activity for 5.8% of the time, and the median of the work-period mean exposure to ELF magnetic fields was 0.18 microT. DC metal inert or active gas welding (MIG/MAG) was used 80% of the time for welding, and AC manual metal arc welding (MMA) was used 10% of the time. The shipyard welders reported welding activity for 56% of the time, and the median and maximum of the workday mean exposure to ELF magnetic fields was 4.70 and 27.5 microT, respectively. For full-shift welders the average workday mean was 21.2 microT for MMA welders and 2.3 microT for MIG/MAG welders. The average exposure during the effective time of welding was estimated to be 65 microT for the MMA welding process and 7 microT for the MIG/MAG welding process. The time of exposure above 1 microT was found to be a useful measure of the effective time of welding. Large differences in exposure to ELF magnetic fields were found between different groups of welders, depending on the welding process and effective time of welding. MMA (AC) welding caused roughly 10 times higher exposure to ELF magnetic fields compared with MIG/MAG (DC) welding. The measurements of static fields suggest that the combined exposure to static and ELF fields of MIG/MAG (DC) welders and the exposure to ELF fields of MMA (AC) welders are roughly of the same level.

Cohort Studies↗
PubMed1989

Chromosome aberrations in peripheral blood lymphocytes of welders and characterization of their exposure by biological samples analysis.

Chromosomal aberrations in cultured lymphocytes obtained from 55 welders and 55 matched controls were analyzed. Depending on the welding techniques and the nature of the consumables and metals welded, three separate groups of welders were examined. Chromium, nickel, and manganese levels in serum and urine were measured to assess the exposure to welding fumes. A statistically significant increase of chromosomal aberrations was found in one of the three analyzed groups of welders. This group used the semi-automatic metal active gas welding process with cored wire containing nickel for welding mild steel. These welders had significantly higher concentrations of serum and urine manganese and, unlike the other welders, significantly elevated concentrations of nickel, both in serum and urine. However, no significant correlations between nickel or manganese levels and the frequency of chromosomal aberrations were found. There was a significant correlation between the length of welding employment of these welders and the frequency of chromosomal breaks, although there was no significant correlation between age and the frequency of chromosomal aberrations. The other two groups of welders, for which the analyses of biologic fluids proved chromium and manganese exposure, had no statistically significant higher frequency of chromosomal aberrations. One of these groups used the manual metal arc welding process with coated electrodes for welding mainly mild steel and the other group used the tungsten inert gas welding process for welding stainless steel. A significant correlation between the daily amount of cigarettes smoked and the frequency of chromosomal breakages, in controls as in welders, was observed. The present data indicate that certain welding processes may generate fumes that seem to have a clastogenic activity.

Adult↗
PubMed2006

Comparison of two sterile connection devices and the effect of sterile connections on blood component quality.

BACKGROUND: Sterile connection devices (SCDs) are used to connect pieces of polyvinylchloride tubing between blood bag systems. After observing a slight decrease in inner diameter of tubing welded with the CompoDock S2 SCD, the effect of welded tubing on storage characteristics of white blood cell (WBC)-reduced red blood cells (RBCs) and platelet (PLT) concentrates was studied. Welds were made with Terumo SCD (T-SCD) or CompoDock S2, and unwelded tubing served as reference. STUDY DESIGN AND METHODS: Three WBC-reduced RBC units or 3 PLT concentrates were pooled and divided to prevent donor-dependent differences. The units were transferred 10 times over (1) tubing with a T-SCD weld, (2) a CompoDock S2 weld, or (3) unwelded tubing. RBCs were stored for 42 days and free hemoglobin (Hb) was measured; PLT concentrates were stored for 8 days and CD62P expression was measured, as markers for blood component quality (n = 10 paired experiments). RESULTS: WBC-reduced RBC units had similar hemolysis at the end of storage: 0.47 +/- 0.28, 0.47 +/- 0.35, and 0.49 +/- 0.38 percent of total Hb, for tubing with a T-SCD weld, a CompoDock S2 weld, or no weld, respectively (not significant). CD62P expression of stored WBC-reduced PLT concentrates was not significantly different between the groups: 20.3 +/- 5.1, 19.8 +/- 5.1, and 22.3 +/- 9.8 percent for tubing with a T-SCD weld, a CompoDock S2 weld, or no weld, respectively. CONCLUSION: The quality of blood components, measured as RBC hemolysis and platelet CD62P expression, is not adversely affected by the presence of a sterile connection in the tubing, made by either the CompoDock S2 or the T-SCD.

Blood Preservation↗
PubMed2006

Pulmonary function abnormalities and airway irritation symptoms of metal fumes exposure on automobile spot welders.

BACKGROUND: Spot or resistance welding has been considered less hazardous than other types of welding. Automobile manufacturing is a major industry in Taiwan. Spot and arc welding are common processes in this industry. The respiratory effects on automobile spot welders exposed to metal fumes are investigated. METHODS: The cohort consisted of 41 male auto-body spot welders, 76 male arc welders, 71 male office workers, and 59 assemblers without welding exposure. Inductivity Coupled Plasma Mass Spectrophotometer (ICP-MS) was applied to detect metals' (zinc, copper, nickel) levels in the post-shift urine samples. Demographic data, work history, smoking status, and respiratory tract irritation symptoms were gathered by a standard self-administered questionnaire. Pulmonary function tests were also performed. RESULTS: There were significantly higher values for average urine metals' (zinc, copper, nickel) levels in spot welders and arc welders than in the non-welding controls. There were 4 out of 23 (17.4%) abnormal forced vital capacity (FVC) among the high-exposed spot welders, 2 out of 18 (11.1%) among the low-exposed spot welders, and 6 out of 130 (4.6%) non-welding-exposed workers. There was a significant linear trend between spot welding exposure and the prevalence of restrictive airway abnormalities (P = 0.036) after adjusting for other factors. There were 9 out of 23 (39.1%) abnormal peak expiratory flow rate (PEFR) among high-exposed spot welders, 5 out of 18 (27.8%) among the low-exposed spot welders, and 28 out of 130 (21.5%) non-welding-exposed workers. There was a borderline significant linear trend between spot welding exposure and the prevalence of obstructive lung function abnormalities (P = 0.084) after adjusting for other factors. There was also a significant dose-response relationship of airway irritation symptoms (cough, phlegm, chronic bronchitis) among the spot welders. Arc welders with high exposure status also had a significant risk of obstructive lung abnormalities (PEFR reduction). There was also a significant dose-response relationship of airway irritation symptoms (cough, phlegm, chest tightness, and chronic bronchitis) among the arc welders. CONCLUSIONS: These findings suggest that restrictive and obstructive lung abnormalities, and airway irritation symptoms are associated with spot and arc welding exposures.

Adult↗
PubMed1991

Long-term changes in the outer part of the eye in welders. Prevalence of spheroid degeneration, pinguecula, pterygium, and corneal cicatrices.

Biomicroscopical examination of possible cumulative changes in the outer part of the eye in 217 male welders with variable welding exposure time showed conjunctival spheroid degeneration in 24% of the welders. The prevalence of changes was significantly increased in welders with the higher exposure time in an age-matched reduced material (98 x 2 eyes; respectively, over and under 40 h.y (number of daily hours of welding multiplied by number of years of welding), welders with stays abroad over one year being withdrawn. The prevalence was also increased in the latter group (41%, N = 40, against 21%, N = 177). Pinguecula was present in 57% of the welders, with a tendency towards larger area with increasing welding exposure. The frequency was increased as compared with that in a control material examined on a previous occasion (41%). Pterygium proper was found in only one subject, pseudopterygium in 5%. Corneal cicatrices were present in about one half of the subjects. The prevalence increased with increasing welding exposure (24% in subjects with short, 42% in those with long exposure; 98 x 2 eyes). Acute welding light keratopathy was experienced by 73%. The mean number of attacks in the 217 welders was 6.4. The frequency was highest in subjects with long welding exposure. The risk of chronic impairment of sight owing to cumulative welding light injuries is very little in the present material, since only 2% had spheroid degeneration on the cornea (only discrete, peripherally located); there was no preponderance of pterygium. On the other hand, the many foreign bodies on the cornea (cicatrices) constitute a risk that apparently does not decrease with increasing welding experience nor repeated attacks of welding light keratopathy.

Adolescent↗
PubMed1996

Heat-induced tissue fusion for microvascular anastomosis.

Laser tissue welding was compared with a crude method of bipolar coagulator-generated heat application for achieving the same heat-induced welding effect in rat microarterial anastomoses. Rat femoral arteries were anastomosed with three triangulated stay sutures and subsequent laser welding or bipolar coagulator application between each pair of stitches. Control (non-welded) vessels received nine stitches placed circumferentially. Laser-welded vessel patency at 1 or more days postoperatively was 90% (65/72) for vessels treated with 0.1-second laser pulses, not significantly different from controls (100%; 16/16) or coagulator-welded anastomoses (88%; 14/16). Pseudoaneurysm rates were higher in the welded vessels (9% and 14% for laser- and coagulator-treated vessels, respectively) than in controls (0%). Histologic and electron microscopic evaluation revealed good healing with no apparent differences between laser- and coagulator-welded repairs. These findings suggest that laser application for microvascular tissue welding is similar to poorly controlled welding with a bipolar coagulator.

Anastomosis, Surgical↗
PubMed1992

Biomonitoring of genotoxic exposure among stainless steel welders.

A biosurvey in the Danish metal industry measured the genotoxic exposure from stainless steel welding. The study comprised measurements of chromosomal aberrations (CA), sister-chromatid exchanges (SCE), unscheduled DNA synthesis (UDS) in peripheral lymphocytes and serum immunoglobulin G. Environmental monitoring of welding fumes and selected metal oxides, biomonitoring of chromium and nickel in serum and urine and mutagenic activity in urine, and evaluation of semen quality were also done. Manual metal arc (MMA) welding and tungsten inert gas (TIG) welding were the dominant welding processes. A higher frequency of chromosomal aberrations, classified as translocations, double minutes, exchanges and rings, was observed in stainless steel welders than in non-welders. SCE was lower in welders working with both MMA and TIG welding than in reference persons. N-Acetoxy-N-acetylaminofluorene (NA-AAF)-induced UDS was lower in 23 never-smoking welders than in 19 unexposed never-smokers. Smoking was a confounding factor resulting in significantly higher CA, SCE, NA-AAF binding to DNA and mutagenic activity in urine. Age was also a confounder: CA, SCE, NA-AAF binding to DNA and UDS increased significantly with age. No significant correlation between SCE and CA or between CA and UDS was found. UDS decreased significantly with increasing lymphocyte count and a higher lymphocyte count was seen in MMA welders than in reference persons and in smokers than in non-smokers. Differences in the composition among lymphocytes in exposed persons compared with non-exposed are suggested. MMA welding gave the highest exposure to chromium, an increased number of chromosomal aberrations and a decrease in SCE when compared with TIG welding. Consequently improvements in the occupational practice of stainless steel welding with MMA is recommended.

Acetoxyacetylaminofluorene↗
PubMed2002

[The vision of welders in France].

PURPOSE: A study was conducted to measure the impact of welding on the vision of welders. METHODOLOGY: This study was conducted in France by the occupational medicine staff of large companies on 1.131 people, namely 850 welders and 281 control subjects. This investigation included two examinations at the beginning and the end of a year. The investigative procedure examined the different welding processes, the percentage of working time spent on welding activity, the length of exposure in years, as well as the medical variables: the optical correction type and history of ocular traumatology. The Visiotest or the Ergovision were used for the visual examination, equipment in common use by occupational medicine departments. RESULTS: The welders were comparatively young (59.53% of them were less than 45 years old). Moreover, for 69.75% of the welders, more than 75% of their activity was devoted to welding. All currently used welding processes were represented, including the modern PLASMA-TIG welding process. No excessive blood alcohol levels were observed in all subjects, but welders did smoke slightly more than the control subjects (40% vs 33%). Self-medication was rather less frequent among the welders, except as regards the use of eye drops, where the proportions were clearly inverted. Optical correction for hyperopia was similar between the two groups; however, as regards myopia, the welders were corrected less often. Lastly, contact lens use was exceptional among the welders. Nearsightedness varied logically with age, but also, inexplicably, with the welding processes. Vision recovery time after exposure to glare was much longer among the welders, except for the PLASMA-TIG processes. No difference was observed in the other parameters of the study. No change in the visual functions studied was noted between the two examinations. DISCUSSION: The examination techniques used showed no impairment of the studied visual functions, probably because companies use protective and preventive eye care methods. Moreover this study is the first to examine the type of welding used by workers and particularly the modern PLASMA-TIG process. The vision recovery time after exposure to glare seems better for the PLASMA-TIG process may be the result of the lower luminous intensity of this process. CONCLUSION: This study was conducted for preventive purposes to contribute to better monitoring of safety and comfort for welding workers and has shown no alteration of the visual function among welders in general.

Adaptation, Ocular↗