Document wJ9j47bNmZE4mpKekbGk4qM3

I. INTRODUCTION Ever since the pronounced increase in tbe incidence of lung cancer among males became apparent, there have been attempts to associate it with one or another of the various elements in the en vironment of roan. The approach used by some workers has been to suspect one or several substances and then set about in an intensive Bearch for lung cancer among persons who have had any exposure to those compounds, la this connection. Smith writes; "The ten dency of authors reporting the coincidental occurrence of primary lung cancer with silicosis or with any other, theoretical etiologic con ditions, has been to emphasize the percentage relationship in extremely small series of cases, with control cases which are not in any way comparable." It would seem inevitable that asbestos should come under scrutiny in this manner, because prolonged exposure to this material is known to'cause a specific type of pneumoconiosis, and because persons who show this form of pneumoconiosis often come to autopsy and pro vide a ready source of material for study. It was in this way that re ports of this simultaneous occurrence of lung cancer and asbestosis be gan to accumulate after tbe report of a case by Lynch and Smith Ln 193S. Within tbe next ten years, about 15 additional cases were reported, and in 1946 Merewetber reviewed all deaths from asbestosis re corded in England since March, 1924. Lung cancer occurred, according