Welding fume exposure and prevalence of chronic respiratory symptoms among welders in micro- and small-scale enterprise in Akaki Kality sub-city, Addis Ababa, Ethiopia: a comparative cross-sectional study.

ABSTRACT

BACKGROUND: Exposure to welding fumes can lead to different respiratory health disorders, including lung cancer, due to long-term exposures. In Ethiopia, large numbers of people are engaged in the welding sector. Often, these workers are exposed to welding fumes at their workplaces, however, the level of exposure and its health effects have never been studied. OBJECTIVE: To measure the level of personal welding fume exposure and assess chronic respiratory symptoms and associated factors, among micro and small-scale enterprise metal workshop workers, in Akaki Kality Sub city, Ethiopia. METHODS: A comparative cross-sectional study involving 226 welders and 217 controls. Chronic respiratory symptoms were assessed using a standardized questionnaire adopted from the American Thoracic Society (ATS). Welding fumes were collected from the welder's breathing zone using 37 mm close-faced plastic cassettes fitted with Polyvinyl Chloride (PVC) filters connected to Casella pumps at an airflow rate of 2 L/min. RESULT: The overall prevalence of chronic respiratory symptoms among welders and controls were 54 (23.9%) and 20 (9.2%) respectively. The geometric mean and geometric standard deviation (GSD) of personal welding fume exposure, among welders was 5.98 mg/m3 (± GSD = 1.54). In this study, 53.3% of the samples exceeded the Occupational Exposure Limit defined by the American Conference of Governmental Industrial Hygiene. Chronic respiratory symptoms were significantly associated with educational status (Adjusted Odds Ratio (AOR) 5.11, 95% CI 1.35, 19.33), respiratory protective equipment use (AOR 3.33, 95% CI 1.52, 7.31), safety training (AOR 2.41, 95% CI 1.10, 5.28), smoking (AOR3.57, 95% CI 1.54, 8.23), welding machine maintenance (AOR 1.87, 95% CI 1.01, 3.59) and welding site (i.e. indoors vs. outdoor) (AOR 6.85. 95% CI 2.36, 19.89). CONCLUSIONS: The prevalence of chronic respiratory symptoms among welding workers was significantly higher than controls. More than half of the samples exceeded the Occupational Exposure Limit. Educational status, implementation of safety training, and welding sites were significantly associated with chronic respiratory symptoms. The results suggested a need to reduce welding fume exposure to improve the respiratory health of the workers.