Chronic obstructive airway disease in pneumoconiosis in comparison to chronic obstructive airway disease in non-dust exposed workers.

Many types of dust, including cigarette smoke, cause an impairment of lung function. This lung function impairment does not affect working capacity provided the dust is not fibrogenetic. Quartz, normally present in coal mine dust in concentrations between 2 and 10% is claimed to be responsible for coal workers' pneumoconiosis (CWP) by some writers. However the evidence is conflicting and firm conclusions cannot be drawn at present. From the clinical point of view CWP is characterized by an increased airway resistance. All correlations between airway resistance, arterial oxygen and carbon dioxide pressure and intrathoracic gas volumes (IGV) in patients having CWP and obstructive airway disease are similar to those in non-dust exposed patients with obstructive ariway disease. Patients with CWP, at equivalent values of airway resistance have smaller mean values of IGV. The relationship between arterial oxygen pressure and pulmonary arterial pressure is the same in patients with CWP and obstructive airway disease as in patients with chronic obstructive airway disease but without CWP. The effect of therapy in CWP with obstructive airway disease corresponds very well to that seen in patients without CWP.