Document Xz7Yya2QEmZyo2jJxKpZdbvey

f G-* J--v 0. Pf ~=n n c> References to Recent Litorcture - 5 concentrations are: Class I--up to 100 million particles per cu, ft.; Clnss II-- 10 million particles per cu. ft. Because of wide variation in limits for the two classes, careful representative s -.npling of the rock -rust bo made by the Department, In numerous dust counts made in the industry in both Class I and Class II rocks, the average dust concentrations found were below 100 million par ticles per cu, ft. and above 10 nillion. Fron this it is concluded that dust control methods ere unnecessary in Class I rock, but are required, according to the code, ir. Class II rock formations, 20 SILICOSIS ID A NORWEGIAN STEEL FOUNDRY. K. Evnng. Nord. Med. Tid. 16, 1085-92 (1933). (Norwegian). The author examined 29 employees who had worked in a small foundry for noro than three years. Of them, 13 showed definite radiological evidence cf silicosis and in two others it was suspected. The cases were distributed throughout the foun dry in all of the occupations. The author points cut that the results are in deed alarming send warrant studies in other sinilar foundries. 21 FINDINGS OF A MEDICAL EXAMINATION OF A GF.0UP OF FETTLERS. J.Chalroagne. Arch. Med. See. et Hyg. i, 527-32 (1938). (Belgian). Fettlurs arc those who use pneunatlc tools to clean sand from castings before they are cent to the sandblast. Fifty-one of these nen from four foundries were examined. The results are not reported clearly, and although x-rays were takun on 12, no reports arc given of then. Most prominent symptoms found wore dyBpnen on exertion, cough, and pulmonary trouble which wore more noticeable in the old er men. 22 THE RESPIRATORY ,.ND CIRCULATORY ADAPTATION TO aCUTE ANOXIA IN SILICOSIS AND 0rJtDIOV,\SCUL.AR DISEASE. K.H. SeeverB, Norbort Enzcr, and T.J. Becker, J.Icd. Dy. k Toxicol 0, 593-634 {December 1938). In spite of aurJic-.s made in the past in reducing exposures to dust concentra tions which rapidly produce tho disabling pulmonary lesions, most workers will, over long periods of time, inhale enough dust to produce a detectable dogreo of pulatnary fibrosis. It is important then to know whether theBO minimal fibroT.ic changes cause any appreciable or measurable pulmonary disfunction. That the changes can cause a disfunction in terns of maximum capacity is granted but the important question is to know whether they can reduce his capacity to perform ordinary daily tasks. At tho prosont time, no satisfactory methods are availablwhich can rote the individual's ability or capacity to perform a given task and therefore rate his degree cf disability. All depend on his cooperation which in many cases la unreliable. In the tests here reported the authors examined patients subjected to atmospheres of reduced oxygen content to study their re actions. Comparatively little hos been done on this type of experiment, partic ularly in the older age groups, and many more tests aro necessary in ordor to correlate results. Although the experiments serve as a mothod of studying the sensitivity of these mechanises (heart, circulatory system, etc.) that oompunsat . for the stress of reduced oxygen, it was found that there was no evidence of latent cardiac incompetence, over and above that occurring with age, in individ uals with varying dogrees of pulmonary fibrosis until the fibrosis was quite far advanced. THE HEART IN PNEUMOCONIOSIS. C.B. Coggin, D.E. Griggs and W.L. Stilson. Am. Heart J. J6, 411 (1938). The basis for this work is the Btudy of 205 cases of pneumoconiosis over a per iod of 20 years. Of those cases 102 come to post mortem while 103 provided only clinical studios; 146 were classified as third atage and 55 as second stage pneumoconiosis. Cardiac enlargement was detected by clinical examination in MiBB-8889779