Respiratory Disability in Coal Miners

To the Editor.—  Perhaps because of the difficulties inherent in disability evaluation, the subject of respiratory disability among coal miners has rarely been marked by calm, dispassionate presentation.Morgan et al (1980;243:2401) argue that arterial blood gas analyses are unnecessary in the evaluation of the condition of claimants under the federal black lung program. In addition to possibly representing a survivor group, it is questionable whether the authors' sample of bituminous coal miners was representative of coal miners from the anthracite fields of northeastern Pennsylvania and the coal fields of the western states.Of greater import is the authors' failure to distinguish clearly between different definitions of illness—between the administrative-clinical black lung and the clinical-pathological coal workers' pneumoconiosis (CWP). The effects of lung injury are frequently additive, and because it is virtually impossible to distinguish among the various causes of lung injury (including cigarette smoking) and resultant pulmonary insufficiency