Document 2RJp03753agxew3G5DndRvEdb

OCCUPATIONAL DISEASES A Guide To Their Recognition Rewritten and Enlarged Edition of Occupation Hazards and Diagnostic Signs W. M. GAFAFER, D. Sc., Editor Division of Occupational Health U.S. DEPARTMENT OF HEALTH EDUCATION, AND WELFARE Public Health Service BGC~314 50 OCCUPATIONAL DISEASES pulmonary insufficiency or from cor pulmonale secondary to obliteration of the pulmonary vascular bed by fibrous tissue invasion. The roentgenographic characteristics of simple coal workers' pneu moconiosis include discrete opacities up to 10 mm in diameter, which may be arranged in groups or spread diffusely throughout the lung fields. In the complicated form of the disease, the earliest roentgenographic evidence of PMF is the presence, usually on a background of simple pneumoconiosis, of larger, less well defined opacities, often resembling reinfection-type tuberculosis in both position and appearance. These large shadows tend to increase in size and to coalesce. They later may contract with resultant severe distortion of the lung architecture. References cochrane, A. L.: The attack rate of progressive massive fibrosis. Brit. J. Indust. Med. 19:52,1962. doyle, h. n.: flinn, R. H., and dreessen, w. c.: A review of the pneumoconiosis prob lem in the United States. Am. Indust. Hyg. Assoc. J. 19*. 317,1958. fletcher, c. m.: Classification of roentgenograms in pneumoconiosis. AMA. Arch. Indust. Health 11: 17,1955. FLINN, R. H.; SEIFERT, H. E.; BRINTON, H. P.I JONES, J. L., AND FRANKS, R. W.I Soft Coal miners health and working environment. Pub. Health Bull. No. 270. U.S. Government Printing Office, Washington, D.C., 1941. cilson, j; c.; Pathology, radiology, and epidemiology of coal workers' pneumoconiosis in Wales. AM.A. Arch. Indust. Health 15: 468,1957. cilson, j. c. and HOGH-jONEs, p.: Lung function in coal workers' pneumoconiosis. Medical Research Council, Special Report Series No. 290. Her Majesty's Stationery Office, London, 1955. gol'gh, j.: Pneumoconiosis in coal workers in Wales. Occup. Med. 4: 86, 1947. heppleston, a. c.: Coal workers' pneumoconiosis. Pathological and etiological con siderations. A.MA. Arch. Indust. Hyg. & Occup. Med. 4: 270, 1951. holt, p. F.: Pneumoconiosis; Industrial Disease of the Lung Caused by Dust. Ed ward Arnold. London, 1957. kerr, l. e.: Coal workers' pneumoconiosis. Indust. Med. & Surg. 25: 355, 1956. martin, j. e.: Coal miners' pneumoconiosis. Am. J. Pub. Health 44 : 581, 1954. SAYERS, R. R.: BLOOMFIELD, J. J.; DALLAVALLE, J. M.; JONES, R. R.; DREESSEN, W. C.; brundace, d. k., and britten, R. h.: Anthr&co-silicosis among hard coal miners. Pub. Health Bull. No. 221. U.S. Government Printing Office, Washington, D.C., 1936. (3) Asbestosis Asbestos is a general term used to describe several fibrous mineral silicates which differ in their chemical composition and physical properties The most important types of asbestos are chrysotile, a simple magnesium silicate: amosite and anthophyllite, which are complex magnesium iron silicates; and crocidolite, a complex sodium iron silicate. About 95 percent of the world's asbestos production is derived from chrysotile. Deposits of this mineral are found in many countries, but the largest mines are located in Canada. Prolonged inhalation of asbe may result in the production 01 accompanied by severe respirat studies of asbestosis, it was rep mechanical action of the ashes in the terminal bronchioles, ir coating of the fiber with the l asbestos or asbestosis body, nism of the lung. If large qu longed period of time, characi progresses until a generalize fibrosis is seen first in the lowe continues, appears in the other cardiac failure may supervene, that asbestos fibers smaller th be incapable of initiating a fibr The roentgenogram of the prolonged inhalation of asbes early or first stages of the die geneous and appear character nodular pattern of silicosis is fields present a ground glass ai In moderately advanced or in evidence but remains gent borders may become indist: referred to as porcupine heart In far advanced or third-st; out the middle and upper lui clear. There is almost comp of the diaphragm and the cost It should be emphasized t be used to estimate the prese disability in lung diseases ii many individuals with radii been able to carry on their several years. On the othe rarely been reported in the ; There is no typical clinica in its onset and is slowly pi tinues. There is a gradual and weight loss, all combi and clubbing of the fingers BCC2315 LAM021565 6113 18261 `I poison->onyl ei- Am. j. n nickel .ents suf155: 889, pentacar:ed with \yethyl ethanol tate. 2- e mild tion of methyl acute : expoforgeteflexia. ression . cellout peamaee CHEMICAL HAZARDS Special Diagnostic Test None. Recommended Threshold Limit Cellosolve, 200 parts per million parts of air by volume or 740 milli grams per cubic meter of air. Cellosolve acetate, 100 parts per million parts of air by volume or 540 milligrams per cubic meter of air. Methyl cellosolve, 25 parts per million parts of air by volume or 80 milli grams per cubic meter of air. Methyl cellosolve acetate. 25 parts per million parts of air by volume or 120 milligrams per cubic meter of air. Butyl cellosolve, 50 parts per million parts of air by volume or 240 milli grams per cubic meter of air. Potential Occupational Exposures Cellophane sealers Cellosolve workers Cleaning solution makers Cotton thread makers Dope makers Dry cleaners Dry cleaning agent makers Dye makers Enamel makers Film makers Gum processors Hydraulic fluid makers Insecticide makers Lacquer makers Lacquer thinner makers Leather makers Nail polish makers .ponu,. to 1 Rep. 72; * f'peat,.,! 0. 1956. impounds oerams in on soitip 21: 308, 1 b>yl tin oxaphene. source of periodical * prepared :ic Effects. -e to DDT. 'wo cases. 5- Governpesticides lent, their nsecfiicide d spray). nethods of -r different pesticides section VIII PLASTICS AND SYNTHETIC RESINS MARCUS M. KEY, M.D. Plastics were so named because at some stage in their manufacture they were soft enough to be formed into various shapes. Synthetic resins were named for their similarity to natural resins, such as rosin. Generally the words are interchangeable, although, for a specific plastic or resin, it is customary to use one in preference to the other; thus, epoxy resin rather than epoxy plastic. There are a number of basic chemical or family groups of plastics and resins, several of which have been arbitrarily chosen for presentation. Each group may be classified as either thermosetting or thermoplastic. Thermo setting resins cure or harden under heat and cannot be reshaped subsequently. Examples are alkyds, allyls, aminos, diisocyanates, epoxies, phenolics, and polyesters. Thermoplastic resins can be softened by heat and reshaped re peatedly. Examples are acrylics, cellulosics, fluorocarbons, nylons, polyethvlenes, polystyrenes, and vinyls. Plastics and resins are made by polymerization or condensation. In poly merization, a large number of identical molecules, called monomers, unite to form a larger molecule, called a polymer. In condensation, a number of molecules, not necessarily of the same composition, unite to form a molecule dissimilar in composition to the components, with the liberation of water or other simple substances. In addition to monomers and condensate components, many other ma terials are used in compounding plastics and resins; namely, accelerators, catalysts, copolymers, dyes, fillers (asbestos, diatomite, glass fiber, mica, quartz, sand and many other substances), mold lubricants, pigments, plas ticizers, solvents, stabilizers, and ultraviolet absorbers. The major hazard from the manufacture, curing, and processing of plastics and resins is contact dermatitis which may be due either to primary irrita tion or to allergic sensitization. As a rule, completely condensed or polym erized resins do not cause dermatitis. Frequent offenders are the catalysts, 251 BCC2917 LAM021567 6113 18263