occupational exposure to welding fumes using different ventilation scenarios

welders may suffer from welding fumes generated during the process if the ventilation systems are improperly applied. the objective of the present work was to study the mitigation of air pollutants at welding stations, using different ventilation scenarios. four air pollutants including iron oxide, respirable dust, ozone, and carbon monoxide were measured during four different ventilation scenarios using us osha and us niosh sampling and analysis methods. meantime, face velocity, volumetric airflow rates, duct velocity, static, and velocity pressures at different locations of the ventilation systems were also measured using bs 1042 standard methods. the paired t -test revealed that with p <0.05 there was a significant difference between occupational exposure to air pollutants in 4 different ventilation scenarios. the results also showed that when local and general ventilation systems were both on, the occupational exposure to iron oxide and carbon monoxide were below than their tlvs, but the exposure to the respirable dust in two welding stations and ozone levels in three welding stations were higher than their respective tlvs. the duct air velocity in three welding stations is higher and in eight stations lower than 10.1 m/s recommended by acgih. the mean value of volumetric airflow rates in all 11 stations were 34.7% of the required volumetric airflow rates based on standard ventilation systems recommended value. the applied general exhaust ventilation was only 35.5% of standard required value. the local exhaust ventilation is expected to mitigate the air pollutants to acceptable levels at welding stations.