Occupational Lung Disease

To the uninitiated the term "occupational lung diseases" encompasses primarily four categories: coal workers' pneumoconiosis, silicosis, asbestosis, and berylliosis. Gee et al. in this primer provide evidence that agents injurious to the respiratory system are far more numerous and diverse than those described in general pathology texts. The breadth of physical, chemical, and biological irritants is delineated in the latter one-third of the book, which contains abstracts from the International Conference on Occupational Lung Disease held in April of 1982. The first two-thirds of the text, written in chapter format, provides a comprehensive survey of the field. Herein lies the usefulness of this book for the general reader, as topics ranging from the medical to the sociopolitical aspects of respiratory pathogens in the workplace are discussed. The first chapter, unfortunately, does not provide an introductory overview and instead launches into an analysis of the physical parameters involved in the deposition and clearance of aerosolized particles. While providing the necessary framework from which to understand the localization of pulmonary pathology by various irritants, its rigorous detail may prove too imposing to the general reader. The chapter concerning the cellular mechanisms of lung injury and repair emphasizes the function of fibroblasts in mediating irreversible lung fibrosis and their potential therapeutic manipulation. The authors admit to excluding the crucial role of type I and II alveolar cells in this process; however, they provide numerous references for those who wish to pursue this topic. Lung cancers, their occupational etiologies, and chemopfevention are briefly reviewed. The potential dietary modulation of tumor develo ment by agents such as vitamin A, vitamin E, selenium, and indoles proves quite stimulating; prospective animal studies and retrospective epidemiological surveys of the association of these agents with cancer incidence are quoted. The author draws evidence from a variety of tumor systems in addition to lung but frequently fails to specify which cancer type applies to the study cited. Much of the remainder of the text examines three important areas in occupational lung disease in depth, namely: asbestos, cotton-dust, and coke-oven hazards. These chapters, in addition to providing an epidemiological background for these problems, address the origins of many of the legislative control measures enacted. The final chapter deals with the utility of screening programs for occupational lung cancers. The conclusions presented are surprising. When approached from a cost-benefit standpoint, these programs have been unsatisfactory. They are quite expensive: a Mayo Clinic study consisting of a chest radiograph, three sputum specimens, and a questionnaire at intervals of four months had cost $135 per person per year. They would require large-scale additions in medical manpower: implementation of a general lung cancer screening program in the United States has been estimated to require an additional 2,000 and 9,000 cytopathologists and cytologic technicians, respectively. Finally, the present cure rates for lung cancer are so poor that early detection of the disease is of limited value. The research abstracts contained in the final one-third of the book, while