Metallurgy / Environmental Monitoring / Quality Control / Prospective studies / Humans / Lung Diseases / Ventilation / Intervention Studies / Metals / Indoor air pollution / Occupational Exposure / Public health systems and services research / Sensitivity and Specificity / Protective Clothing / Lung Diseases / Ventilation / Intervention Studies / Metals / Indoor air pollution / Occupational Exposure / Public health systems and services research / Sensitivity and Specificity / Protective Clothing