Document e7n6Rp21JJw0XYVR67x1pDK99

GENEMAI 6.29.02*054599 ifELECTR MAIN OFFICE AND FACTORY CHICAGO 20ia JACKSON BOULEVARD X-RAY CORPORATION BRANCH OFFICES IN ALL PRINCIPAL CITIES CABLE AOORESS VI CTO R X RAY C HICAG O CHICAGO April 1, 1935 North. Carolina Industrial Commission Raleigh ' North Carolina Dear Mr. Wilson: Attention: Mr. T. A. Wilson, Commissioner In response to your recent letter, we are sending you herewith a reprint of a paper by H. J. Holmquest, B. S. {M. B.) , on the "Industrial Aspects of the Silicosis-Problem," which we hope will be of value to you in your con sideration of the installation of- x-ray equipment for radiography in silicosis. There are of course many angles to be considered, and we believe that our representative can be of real service to you. For this reason we are referring your letter to our branch office located near you, the General Electric X-ray Corporation, 114A W. 5th Street, Charlotte, N. C., so that our representa tive may arrange to get in touch with you and give you full particulars regarding the type of equipment which will meet your individual conditions to the best advantage. Very truly yours MJPrice/wW Publications Division t DEFINITION AND NOMENCLATURE The word "pneumonoconiosis" is derived from two Greek words meaning "lung" and "dust". It implies a disease of the lungs characterized by fibroid induration and pigmentation due to the inhalation of excessive quantities of dust.- Pneumonoconiosis has been used as a general term, while other terms have been used to identify the type of dust responsible for the disease which varies with the industry or oc cupation, such as: Aluminosis, - Aluminum werkers: Anthracosis, - Coal miners; Asbestosis, - Asbestos workers; Byssinosis, - Cotton mill workers; Chalicosis, - Potters; ' Ptilosis, - Ostrich feather workers; . Siderosis, - Iron grinders; .... Silicosis, - Hock drillers (Grinder's disease); Tabacosis, - Tobacco workers; - - . Silicosis is probably the most important form of pneumonoconiosis. The com mittee on Pneumonoconiosis and the committee on Standards of the American Public Health Association, at a joint meeting in November of 1932, adopted the following definition of silicosis; "Silicosis is a disease due to breathing air containing silica (Si 02), characterized anatomically by generalized fibrotic changes and the de velopment of miliary nodulation in both lungs, and clinically by short ness of breath, decreased chest expansion, lessened capacity for work, absence of fever, increased susceptibility to tuberculosis (some or all of which symptoms may be present) and by characteristic x-ray findings. The disease is divided arbitrarily into first, second and third stages for convenience of description and possible compensation purposes". Concerning what happens when dangerous amounts of fine silica dust are breath ed in by exposed workers, Sappington (Silicosis - An interpretive Review of Ac cumulated Experience, published 1932, by Industrial Relations, 844 Rush street, Chicago) writes: - "In the first place, we .are concerned only with dust particles measuring under 10 micromillimeters in diameter, because it is only particles of such microscopic size that can get into the lung tissue- proper.- Since a micromillimeter is equivalent to one twenty-five thousandth of an inch, it will be seen that dust particles which can cause trouble are microscop ic in size and cannot be observed or counted except by n^Lcroscopic methods. "The air sacs of the lungs, the smallest structure in the lungs, are also of microscopic size. In the microscopic cross-section of an-air sac the air space will be seen in the middle, around which are very thin micro scopic walls, in which are the blood and lymph vessels. When particles of dust coma into the air space in the middle of the. air sac (as shown in cross-section view under a microscope) the so-called devouring cells, which are the phagocytes or white cells of the blood, are attracted and migrate through the walls of the vessels into the air space. -These de vouring cells then actually surround foreign material or dust particles ^W wwgii W4*w n o-. -t. i UA 01J.C ai.i oao , 1/J.U UUgU OHO YY<a.J.i) OX the blood and lymph vessels and are carried by the blood and lymph . streams to various portions of the body. "When the number of dust particles becomes considerable,' the' number of devouring cells not only block the lymph glands which are encountered .in the course of lymph vessels, but also, in many instances these cells disintegrate, leaving free silica in the glands, which, then undergo fi brosis. This is what makes them visible in x-ray pictures because of the increased density resulting from the formation of fibrous "tissue. "Following this, there is a backing up of the devouring cells and their enclosed dust particles into the lungs proper, and here a fibrous tissue replacement also takes place. "It is believed that free silica particles, being non-absorbable, are a constant source of irritation, and a serum which is the reaction to ir ritation is poured out in the lung tissue. This serum changes to fibrous tissue gradually. This is a characteristic reaction which may take place in any part,of the body where foreign material is not absorbable and pro duces an outpouring of serum, which is eventually changed to fibrous strands. Eventually fibrous tissue develops in small, well defined and 'limited nodules, as they are called, throughout the entire lung tissue. "Since these nodules are more dense than the lung tissue itself, they show in the x-ray picture, giving an appearance which is called "'mottling' ", ' symptomatology . . Silicosis is a disease that usually develops very slowly.' However, it may de velop in two years or even less. Its rate of development is dependent on: (1) The amount of dust in the inspired air ' (2) The amount of silica in the dust (3) The extent of exposure Silicosis is insidious in its onset and progress and presents but few symptom or physical signs in its early stages. Patients with early silicosis in umcompli cated form are usually well-nourished and apparently healthy. . . Based on a study carried out among 7,722 men employed as miners in the Picher District of Oklahoma, Sayers of the USPHS (Clinical Manifestations of Silicosis, J. A. M. A., Aug. 19,1933) summarizes the subjective symptoms of silicosis thus: SUBJECTIVE SYMPTOMS OF SILICOSIS Dyspnea Cough Expecto Hemop Degree of Silicosis ration tysis flight Loss of Loss ( Sweats Strength Appet Essentially negative 10.2 13.9 0.9 1.0 First Stage Silicosis 18.4 18.2 1.0 2.0 Second stage Silicosis 30.8 23.3 3.2 5.5 Third Stage Silicosis 43.7 34.4 3.1 0.0 Silicosis with Tuberculosis 44.2 42.0 3.7 11.2 Uncomplicated Tuberculosis ------ 44.2 7.7 17.5 0.9 3.5. 1.9 1.3 6.4 3.3 4.3 11.8 5.9 3.1 25.0 6.2 6.0 24.0 12.4 9.6 ' 29.8 14.4