gravimetric and analytical evaluation of welding fume in an automobile part manufacturing factory

background: welding is one of the most exercised industrial processes which welders are exposed to chemical and physical hazardous agents. this study was conducted to evaluate occupational and environmental exposures to aerosols generated by welding processes in a factory. methods: a total of 28 samples of aerosols were collected at 4 different locations including indoor, outdoor, source of welding and the stacks using a high volume pump with a volumetric flow rate of 112 lit/min calibrated with a dry gas meter. the samples were collected on round 110 mm fiber glass filters, measured gravimetrically, extracted using nitric acid and analyzed with atomic absorption spectroscopy method for heavy metals including fe, mn, ni, cr3+, cr+6, co, and zn. results: gravimetric measuring has shown the mean values of indoor air: 1.33 mg/m3, breathing zone of the welders using coated electrodes and co2: 7.25 mg/m3 and 6.45 mg/m3 respectively and in ventilation exhausts: 95.07 mg/m3. the mean values of fe, mn, and ni were 0.8, 0.041, and 0.00 mg/m3 in indoor air, 2.7, 0.18, and 0.15 mg/m3 in breathing zone of welders used coated electrodes, and 1.75, 0.08, and 0.22 mg/m3 in breathing zone of welders used co2 welding respectively. the concentrations of cr3+, cr+6, co, and zn were too low to be detected. conclusion: the welders were exposed to high concentration of metallic fumes, which raise the risk of pulmonary dysfunction and other health disorders. using suitable respiratory masks and appling the effective local ventilation system may improve the working condition.