Document jBr6yRM0vOG7nnpKKkxQDLbvp

.240 CHAPTER 12 1946 Guide . ^ *1--A.S.H.V.E. Research Paper--Comfort with Summer Air Conditioning, by Thomas Chester N D Adams, C. R. Bellamy, G. D. Fife, E. P. Heckel, Dr. W. J. McConnell. K C. McIntosh. A. B. Newton B. F. Raber and C. Tasker. (A.S.H.V.E. Transactions, Vol. 48,.1942, p..107). -A.S.H.V.E. Research Report No. 1102--Shock Experiences of 275 Workers After Entering and Leang Cooled and Air Conditioned Offices, by A. B. Newton. F. C. Honghten. Carl Gutberlet, R. W. Onalley and M. C. W. Tomlinson (A.S.H.V.E. Transactions, VoL 44. 1938, p.'57i).: ' ' . **7'AlS.H.y.E. Research Report No. 1055--Cooling Reanirements for Summer Comfort Air Coni ditionmg;d>y F. a Houghten, F. E. Giesecke. C. Tasker and-Carl Gutberlet (A.S.H.V:E. Transactions. ... VrA ?-H.V E Research Report No. 755--Effective Temperature for Persons Lightly Clothed and Wilting,in sull Air by F. C. Houghten. W. W. Teague and W. E. MiUer (A.S.H.V.E. Transactions, Vol. 32, 1926, p. 315)( _ .**--A.S.H;V.E. Research Report No. 1106--Air Conditioning in Industry; by W. L. Fleisher A. E Stacey, Jr., F. C. Houghten and M. B. Ferderber (A.S.H.V.E. Transactions, Vol. 45, 1939, p. 59). of Air Conditioning to Premature Nurseries in Hospitals, by C. P. Yaglou, Philip Drinker and K. D. Blackfan (A.S.H.V.E. Transactions, VoL 36, 1930. p. 383). ... *7~A.S.H.V.E. Research Report No. 1012--Study of Summer Cooling in the Research Residence for the Summer of 1934, by A. P. Kratz, S. Konzo, M. K. Fahnestock and E. L; Broderick (A.S.H.V.E. Trans actions, Vol. 41. 1935. p. 207). DuBois. D. and E. F. (Archives of Internal Medicine, 1916, Vol. 18, p.865). CHAPTER; 13 _y^tV Conditioning, in the prevention id treatment o^ d&ideaie anc Control of Airborne Infection, Value of-Air Cooling-Under Tropical Conditions, Treatment of Disease, Operating Rooms, Nurseries for Premature Infants, Fever Therapy, Cold Therapy, Allergic Disorders, Oxygen Therapy, Evacuation of Sick and Wounded, General Hospital Air Conditioning THE late war has caused an increase of interest in the preventive aspects of air conditioning. It has re-emphasized the importance of the control of airborne infection and has demonstrated the value of air cooling under tropical conditions for the prevention of heat rash, for proper rest and sleep, and in the convalescence of patients. CONTROL OF AIRBORNE INFECTION Any program of air sanitation is influenced by a number of factors * *3' *. In the winter months, the closing of doors, windows and other means of access to the outside air to.conserve warmth and further the crowding of persons indoors provides conditions conducive to a high incidence of contagion. This seasonal phenomenon, illustrated in Fig. 1 which represents a study made by the U. S. Public Health Service, will concern the ventilating engineer in so far as air quality, determined by tempera ture, humidity, air replenishment and type of air movement and by. freedom from contamination, is a major intrinsic factor. : Apart from the seasonal picture of airborne contagion are such extrinsic factors as rate of turnover of personnel and the marked, susceptibility of the recruit in comparison with permanent personnel6 as shown by studies of military personnel housed in" barracks, Fig. 2. These extraneous variables and' the factor of contact infection (direct spray) tend to complicate any evaluation of the effectiveness of air sanitation for elimination of micro organisms in droplet-nuclei and droplet-dust.. Thus, .control, measures may eliminate consistently 90 per cent of airborne organisms in laboratory tests, but cannot effect a decrease in actual incidence of infection ex ceeding 30 per cent. Thirty per cent may be the maximal reduction in infection possible by air treatment methods. The distinction should be clearly drawn,, therefore,- between the effectiveness of a procedure in laboratory tests and its effectiveness and applicability iffactually reducing the incidence .of airborne disease. - The following sequence of events has been postulated as occurring in. a large proportion of intra-ward infections: ' (a) ejection of relatively large protected infective particles from patients, (6) rapid venting or settling of these particles- so that ;those remaining airborne - are in low concentration, (c) survival of infective particles to permit the accumu lation of high concentrations-on surfaces, id) repeated reintroduction of infective particles.into the air under the stimulus of ward activities or by air currents of the order of 50 fpm over the floor, and' (e) extension of infective areas bV air turbulence throughout the ward or. hospital. The most important link in this probable infection, chain has been demon strated to be the reintroduction of particles into the air 6. 241 '