health risk assessment of exposure welders to five toxic gases on three welding types

Background: Hazardous chemical agents in the welding operation are a mixture of metals fumes and toxic gases, which inhalation of those causes adverse health effects among welders. The Emissions of gases in the Workplace is a logical reason for concerning about the potential development of respiratory disease. The aim of present study was to determine the concentration values of gases emission during arc welding and the risk assessment by method SQRCA.Materials and Methods: This cross-sectional study was conducted in Iranian Steel Industry from three process including Plasma arc welding(PAW),Submerged arc welding(SAW) and Gas tungsten arc welding(GTAW). Direct reading instruments were used for sampling of gases carbon dioxide(CO2), carbon monoxide (CO), nitrogen monoxide(NO), nitrogen dioxide (NO2) and Ozone(O3) were measured. SQRCA method was used for risk assessment of gases.Results: Results shown Concentrations of O3(0.356 ppm), CO(41.642 ppm), NO(6.357 ppm) and NO2(4.871 ppm) were found to exceed their Threshold Limit Values (TLV) values, while the concentrations of CO2(3879.285 ppm), was below those TLV level. exposure concentration maximum with all of gases except CO2, in SAW welding observed. SQRCA method showed that among the gases, highest and least risk rating related to ozone(VH) and nitrogen monoxide(N) gases, respectively, while risk rating for CO2, CO and NO2 were low, high and Very High, respectively.Conclusions: In our study ,exposure values were higher than TLV-TWA and the results of risk assessment showed that,control Engineering and Respiratory protective equipment (RPE) should be applied for welders specially in SAW, PAW and GTAW processes.

کلیدواژه ها:

welding processes ، SQRCA method ، exposure ، gases