Photobiological hazards in shielded metal arc welding

Abstract

PurposePhotobiological hazards caused by artificial optical radiation are assessed for the most commonly used arc welding technique, the SMAW (Shielded Metal Arc Welding), which operates with a hand-held system and is widely used both at occupational and domestic environments, expanding our previous investigation of a robotic arc welding process. MethodsThe complex exposure limits of the emitted blue and visible light, ultraviolet and infrared, are assessed through the European Directive 2006/25/EC, using three dedicated sensors set to measure irradiance from various typical welding procedures in the controlled environment (currents, electrodes, etc.) of a welding laboratory. In this sense, field measurements are employed, applying existing policies. Occupational limits are also applicable to the domestic welding. ResultsApart from sub-minute overexposures, which were detected in every spectral band, overexposures in the order of one second were also observed at very close distances, which are common at complex working environments. Investigation of the initial welding procedure, which is often performed without the use of Personal Protective Equipment, revealed exposure of the order of the corresponding limit. ConclusionsSimulation of a ‘bad’ welding procedure revealed increased exposure, indicating the importance of training in the occupational environment. Concern for the exposure of near-by workers (working a few meters away from the welding point) is also crucial. Future work needs to incorporate more welding techniques and measurements from original workplaces, in order to set the basis for an integrated risk assessment and provide valuable information concerning occupational diseases.