نتایج جستجو برای: welding fume
تعداد نتایج: 17135 فیلتر نتایج به سال:
Welding fume contains elements that, in their pure forms, can be hazardous to worker health if inhaled or ingested. Therefore, the chemical composition of welding fume must be examined when considering fume toxicity. Various chemical analysis techniques are presented and their applicability to airborne particles is described. Knowledge of particle size is important because a given characterizat...
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 (NO2) and ozone (O3) were sampled for thirty-eight workers. Personal exposure air samples for welding fume metals were collected on 37 mm open face cassettes and ni...
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 uprig...
In the present study, the fumes generated from manual metal arc (MMA) and submerged metal arc (SMA) welding of low temperature service steel, and the chromium and nickel percentages in these fumes, were measured at various horizontal distances and vertical heights from the arc in order to obtain a three dimensional distribution. The MMA welding fume concentrations were significantly higher than...
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 (SMA...
Although the incidence of pneumoconiosis has been decreasing in Japan, welders’ health hazards due to welding fume inhalation are still serious, because effective engineering methods for controlling fumes are technically difficult to implement in many welding shops. In the 6th notification of general prevention of dust hazards issued by the Japanese Ministry of Health, Labor and Welfare (2003–2...
Welding fume contains various metals and pulmonary effects from their inhalation are largely unknown. We have studied the effects of exposure to welding fume in sheep. The animals were exposed to either a bolus dose of welding fume solution or to five weeks daily exposure. Lung physiology parameters were studied and biopsies taken. Magnetopneumography was used to register the longterm exposure....
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-kn...
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 grea...
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 inhalab...
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