Respiratory symptoms and pulmonary function among welders : a cross-sectional study in an automobile assembly factory in Guangzhou

Abstract

Objective: To investigate the adverse effect of welding exposure on pulmonary function test and respiratory symptoms in welders. Design: Cross-sectional study Setting: Guangzhou, China Subjects: 350 male welders in an automobile assembly factory and 350 controls in MTR corporation who had no exposure to welding fumes and toxic gases. Methods: The data was collected from Guangzhou No.12 People’s Hospital. This inclusion and exclusion criteria for subjects and controls were set. The relationship between pulmonary function, respiratory symptoms and welding exposure was investigated by comparing the prevalence of abnormal pulmonary function and respiratory symptoms among welders and non-welders. Chi-square was used for comparison of categorical variables. Logistic regression was performed to estimate odds ratios after adjustment for age, working duration and smoking habits. Results: After accounting for age, working years and smoking habit, the adjusted OR (95% C.I.) of pulmonary function among welders and non-welders was 1.425 (0.916, 2.215), suggesting that welders was associated with a 1.43 times as high the odds of being tested abnormal pulmonary function as non-welders. However, there was no significant (P=0.116) difference in odds between welders and non-welders. The differences of respiratory symptoms in odds between welders and non-welders was not significant (P>0.268). But when restricted to smokers, significant difference (p<0.05) in abnormal pulmonary function was found between welders (17.5%) and non-welders (10.6%). Of the respiratory symptoms, only prevalence of cough was found to be statistically higher (p<0.05) among welders (16.1%) who smoked than non-welders (8.0%) who smoked. Conclusion: It is not evident from my study thatwelders who worked in a well-ventilation working environment and well protected by wearing personal protective equipment are subjected to increased prevalence of abnormal pulmonary function and respiratory symptoms. Studies with larger samples and longer period of observation are warranted. Smoking was observed to be the most important factor contributing to the presence of abnormal pulmonary function and respiratory symptoms. Smoking cessation would be needed to carry out in welders.