Document jBMDJ7Xe4JOv1jvxjBbZLx89N

Preliminary Bust Survey for Aobcatoo Toxtile Institute June, 19**7 19. STATISTICAL ST.OTZS CF MEDICAL LECOHDS There are tvo very lnportent queotiorj concerning the physiological nature of asbestos that have not yet boon answered by any published investi gation: 1. . Vhat is the expectation of asbestosis in workers exposed core then 15-20 years to lev concentrations of asbestos dust? Among the 500-odd workers vho composed the subjects in the U.S. Public Eoelth Service study, there vers abnormally fev vho hed been exposed for core than 15 years and. practically none over 20 yearo. These facts seriously effected the conclu sions that could be drawn. - 2. Is there e progression to advanced asbestosis after exposure ei' an individual has been discontinued or has been reduced to very low levels, due to action cf dust deposits from earlier exposure? This question, is of very great importance to intelligent nodical supervision of workers in these plants. It is virtually certain that statistical investigations of existing records would throw valuable light cm these questions. Hone of the plants visited during this Inquiry have sufficiently extensive and systematic records to provide satisfactory.answers to theso quoations, but the medical department of Metropolitan Life Insurance Company, under Dr. A. J. Lanza, have x-rays of a number of men obtained in the early 1930's which could provide the nucleus of soma useful information, depending on how many of the original group are available for re-x-ray. MTS 007910