Occupational respiratory diseases attributable to exposure to various agents encountered at the workplace include a large variety of conditions characterized by the development of airway obstruction (e.g., asthma) or a disease predominant in the pulmonary parenchyma, often inducing a “restrictive syndrome,” with a reduction of lung volumes (e.g., asbestosis/silicosis) [1–3]. A preexisting condition such as asthma or chronic obstructive pulmonary disease (COPD) can also worsen following exposures at the workplace, or be a cofactor in the development of a disease (e.g., asbestosis and lung cancer). Respiratory problems associated with work are a major cause of disability, work absenteeism, and mortality. The specific prevalence of these problems changes with time and is difficult to establish. We estimate that about 50% of all diseases acquired at the workplace are affecting the respiratory system.