Journal of Health and Safety at Work

Introduction: Risk assessment of Toxic or hazardous chemicals enables the Industrial Hygienists to make the appropriate decision in providing healthy work place. This project was conducted in an assembling plant,(4workshop) of an Automobile Industry in IRAN with 2 types of welding operations, including GMAW (CO2 welding) and Spot resistance welding operations.

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Method and Materials: Welders` exposures were assessed via collecting 143 breathing zone air samples based on NIOSH 0500 method. Risk assessment was carried out using Singapore recommended method.

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Results: Finding showed that the mean of welders exposure in GMAW and Spot resistance welding operations 5.61 ± 5.78and 2.38± 2.15 mg/m3, respectively(p<0.05). The results showed that in GMAW welders had the highe exposure in comparison with Spot resistance welders (p<0.05). The findings also demonstrated that the risk rate of GMAW welders were high, while this rate for Spot resistance was low.

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Conclusion: more hygienic attention is needed for GTAW welders. Control approaches are required including effective engineering control, conduct air monitoring, biological monitoring training, adopt respiratory protection program, develop and implement safe and correct work procedures and finally reassess the risk after all the controls have been done.

Introduction: The present study was carried out to compare contrast sensitivity among three groups of professional welders including (1) those who use gas metal Arc welding (GMAW) (2) those who use shield metal Arc welding (SMAW) and the group that uses resistance welding.
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Material and Method: In this research, all the welders who use GMAW, SMAW and resistance welding working in an industry who were all male, performed contrast sensitivity test, using Freiburg. The contrast sensitivity test was done at three spatial frequency of 1cpd, 5cpd and 15 cpd under a constant condition. The three selected groups were similar regarding age and work experience. The result of the three groups at each spatial frequency were recorded and compared with other groups.
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Results: ANOVA test showed that decrease contrast sensitivity in spatial frequency of GMAW group at the spatial frequency 15cpd, significantly decrease comparing to SMAW group (p=0.028) and resistance welding group (p=0.041). The mean (SD) of contrast sensitivity at frequency of 1cpd, 5cpd and 15cpd was respectively 140.69±51.8, 172.7±43.75 and 39.8±25.92 for the GMAW group and 157.8±42.2, 183.21±32.01 and 60.57±54.30 for the SMAW group and 149.10±50.68, 180.60±35.42 and 57.38±39.22 for resistance welding.
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Conclusion: Although all welders use goggle or other personal protective equipment, loss of contrast sensitivity of GMAW workers can be attributed to the cumulative effects of the radiation.