Pneumoconiosis

The International Labor Organization defines pneumoconiosis as the accumulation of dust in the lungs and the tissue reactions to its presence. The diagnosis of any pneumoconiosis involves a detailed evaluation of exposure to any agent known to cause interstitial lung diseases (ILD). Given the long latency of several of these diseases, a complete occupational history and exclusion of other causes of ILD are required. Within this context along with consistent radiographic and pulmonary function abnormalities, a diagnosis of pneumoconiosis can be made with reasonable certainty. Asbestos is a general term for a heterogeneous group of hydrated magnesium silicate that tends to break up into fibers. These fibers, when inhaled into the lungs, can cause a spectrum of lung disorders including benign conditions such as pulmonary fibrosis and malignant conditions such as lung cancer and mesothelioma. Asbestosis is the interstitial pneumonitis and fibrosis caused by inhalation of asbestos fibers. Silicosis represents varying degrees of lung disease caused by inhalational exposure to crystalline silica (silicon dioxide), usually in the form of quartz (present in granite and sandstone). Other forms of crystalline silica include cristobalite and tridymite. Over time, exposure to inhaled silica can cause worsening inflammation and some patients may develop pulmonary fibrosis. Hard metal is different from heavy metal (e.g., lead, chromium, cadmium, mercury) and is produced by compacting powdered tungsten carbide with cobalt (between 3–25%) in a process called sintering which is then heated to approximately 1500 °C rendering it very hard and thus making it suitable for sharpening metals, drills, and polishing hard metal parts to precise dimensions, including diamonds and dental prostheses. Moreover, it is used in varying amounts to make coolants, which when aerosolized is easily inhaled—thus causing downstream effects within the airways and lungs.