ABSTRACT
BACKGROUND: Vietnam is a rapidly industrializing country with increasing needs for building materials, including refractory bricks. The manufacture of refractory bricks results in high levels of free silica, a recognized occupational hazard. METHODS: A cross-sectional survey was conducted among 158 employees using a respiratory symptom questionnaire and ILO classification of radiographs for pneumoconiosis. RESULTS: The prevalence of radiographic silicosis (ILO category 1/0 and greater) was 10% in all workers with evidence of a dose-response gradient. Pneumoconiosis prevalence increased from 0% in workers employed < 10 years at the plant to 18% for workers employed > 20 years (trend test P = 0.01 for each year increment after adjusting for gender and tobacco use). CONCLUSIONS: Workers in this plant demonstrate a consistent pattern of radiographic evidence of pneumoconiosis, which appears to be related to duration of work. Future studies should assess exposure control measures that are appropriate to countries undergoing rapid industrialization such as Vietnam.
