Vitamins Aid Reduction of Lost Time in Industry ARTHURD. HOLMES AND MADELEINE G. PIGOTT, The E. L. P a t c h Company, Boston, Mass., AND WM. ALFRED SAWYER AND LAURA COMSTOCK, Eastman Kodak Company, Rochester, N. Y. ILLS (15) has estimated that the 36,000,000 wage earners in the United States are absent from their work on account of illness a t least 250,000,000 working days per year. The recognition of economic waste of such proportions has stimulated inquiry concerning the type of illnesses responsible for this excessive amount of lost time, and during recent years a number of studies have been made to collect data concerning various problems associated with illness of industrial employees. The Metropolitan Life Insurance Company (14) states: “The amount of absenteeism in large business and industrial establishments due to minor illnesses is seldom appreciated until the facts are thoroughly reviewed.’’ This company found common colds were among the chief sources of lost time (6700 employees), amounting to 420.7 per 1000 employees for the year, Brundage (4)found from observations of 3000 employees for a 10-year period that “Respiratory diseases caused approximately one-half of all the absences.” I n a later paper ( 5 ) the same author concluded from the data obtained in an 8-year study of a group of thirty-five t o forty industrial sick benefit associations, having a combined membership of 100,000 to 150,000persons, that respiratory diseases caused 42.4 per cent of the total disabilities (for more than one week) from sickness and nonindustrial accidents. Sydenstricker (23) studied the incidence of illness in 1800 families during a 28-month period and found that 60 per cent of all illnesses were due to respiratory conditions. I n an extensive study of the amount of time lost from their usual occupations because of disabling illnesses, Mills (15) found among 570,000 people in industrial communities an average loss of time of nearly 7 days per year; of 3000 employees (electrical industry), an average of 7 days per year; of 1282 office workers (mostly women) an average of 8 days per year; and of 16,000 employees (rubber industry), 8 days per year. Concerning the cause he says: “Colds and bronchial conditions, and influenza and grippe, are obviously the most serious causes of disability from the standpoint both of frequency and of days lost.” Since colds and similar infections cause such a large portion of lost time among industrial workers, it is highly desirable to reduce the incidence of these diseases. Numerous investigators (1-3, 6-8, 10-12,16, 18, 90-22, 24-16) have concluded from their studies that an important function of vitamin A is to raise the resistance of the body to various types of infections. On account of this characteristic of vitamin A, Mellanby has termed it the “anti-infective” vitamin. I n fact, he has claimed ( I S ) : “We have treated five cases of puerperal septicaemia from whose blood haemolytic streptococci were grown, with preparations rich in vitamin A. All made complete recoveries, thus indicating that vitamin A, when given therapeutically, can raise the resistance of the human body against septic and infective micro-organisms.” I n view of this recognized anti-infective value of vitamin A, it seemed logical to consider the possibilities of decreasing the lost time of those dependent upon industrial employment for a livelihood by supplementing the dietary Kith material rich in vitamin A. Accordingly an investigation has been conducted t o determine whether using cod-liver oil as a
supplement to the usual home diet would be of definite economic value for decreasing lost time caused by colds and similar infections.
TESTS WITH COD-LIVER OIL The cod-liver oil was prepared by the direct steam process from fresh livers. Its chemical and physical characteristics (17) were as follows: Specific gravity 0.9249 Refractive index 1,4813 Sa pnification value 189.4 Ioxine number 144.8
Free fatty acid, % Unsaponifiable material, % Vitamin A, unita per gram Vitamin D,units per gram
0.59 1.243
hlore than 1000 More than 130
One hundred eighty-five persons served as subjects of the experiment (115 women and 70 men). The control group of 128 persons contained 88 ’rvomen and 40 men. The members of the experimental group were given one tablespoonful of cod-liver oil daily, during the morning or afternoon rest period, as a supplement t o their usual home dietary. In order that the investigation should include a reasonably wide range of weight and health conditions of industrial workers, men and women engaged in a variety of tasks such as office, light machine, and heavier machine work were selected as subjects of this study. Detailed information was collected concerning the age and weight of the subjects a t the beginning of the test and records were kept of the weight, the number of colds contracted, and the amount of time lost during the time of the experiment. The 4-month experimental period lasted from December to March, inclusive-the season of greatest prevalence of colds and of minimum sunlight and resistance to colds. The age range of the subjects was divided into four classes: 20 years and under; 21 to 30, inclusive; 31 to 45, inclusive; and over 45. The distribution of the subjects in these four classes was 20 years and under, 8.6 per cent; 21 to 30, 51.9 per cent; 31 to 45, 35.7 per cent; and over 45, 3.8 per cent. It will be noted that 87.6 per cent of the subjects were between 21 and 45 years of age. The age range of the subjects of this experiment is thought to be typical of industrial workers. The weight range of the subjects was also divided into four classes. According to Emerson (9) persons within 7 per cent above or below ideal weight are considered of average weight, those 7 per cent or more below ideal weight as underweight, and those 7 per cent or more above ideal weight as overweight. A large majority of the subjects of this test were within average weight. Hence, it seemed desirable to modify the classification to indicate the ratio of persons above and below ideal weight. When the subjects were divided in this manner, it was found that 28.3 per cent were 7 per cent or more below ideal weight, 27.8 per cent were between ideal weight and 6.9 per cent below ideal weight, 19.4 per cent were between ideal weight and 6.9 per cent above ideal n-eight, and 24.5 per cent were 7 per cent or more above ideal weight; thus the subjects were quite uniformly distributed among the four classifications. I n order that the results of the test should be of fairly general application, the subjects were so selected that different
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September, 1932
INDUSTRIAL AND ENGINEERING CHEMISTRY
types of occupation were represented. Thirty-four per cent of the subjects were engaged in office work, 27.6 per cent in light machine work, and 38.4 per cent in heavier machine work. This distribution of the subjects for the three types of occupations is believed to be fairly typical of many industrial concerns. The average daily energy expenditure of the subjects obviously varied with the different types of work a t which they were employed. The average weight of the subjects was 125 pounds for women and 151 pounds for men. It was assumed that all the subjects devoted 8 hours to sleep and 2 hours to light exercise. The office worker was employed 8 hours, and the other two groups 8.5 hours each. The balance of the time for all subjects was considered as sitting at rest. The values reported by Sherman (I@) were used for computing the energy expenditure--0.45 calorie per pound per hour during sleep, 1.1 calories during light exercise, 0.65 calorie during sitting a t rest, 0.91 calorie for the office worker during work, 1.17 calories for the light machine worker during work, and 1.56 calories for the heavier machine worker during work. Thus the average daily energy expenditure for women was 2100 calories for office worker, 2400 calories for light machine worker, and 2800 calories for the heavier machine worker; for men it was 2540 calories for the office worker, 2865 calories for the light machine worker, and 3356 calories for the heavier machine worker.
PREVALENCE OF COLDS A daily record was made of all instances of illness or absence of subjects. From these data a compilation was made of the number of subjects who developed colds during the experiment. For the purpose of comparison, cont,rols were selected which were as nearly identical as possible to the subjects in age, weight, and occupation. The 185 members of the cod-liver oil group and 128 members of the control group were distributed through a number of rooms. Since persons working in the proximity of a person developing a cold are likely to be exposed to the infection, it has seemed desirable to report the occurrence of colds in the two groups for each of the different rooms. These data are given in Table I.
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TABLE 11. SUBJECTS WITH Xo LOSTTIMEDURING EXPERIMENT ROOM 1 2 3 4 5 6
Total
COD-LIVER OIL GROUP Subjects Per cent 49 71 0 7 38 9 3 27 3 9 56 3 12 27 3 16 55 2
-
-
96
51 9
CONTROL GROUP Subjects Per cent 28 52 8 2 22 2 4 33 3 3 20 0 6 35 3 9 40 8
-
-
52
40 6
Thus, 96 members of the cod-liver oil group and 52 of the control group lost no time during the experiment. Considered on a percentage basis, 51.9 per cent of the cod-liver oil group and 40.6 per cent of the control group lost no time during the period of the experiment. In Table I1 a comparison is made of the lost time of the subjects of the experimental and control groups during the year of the test. Since complete data had been recorded for the subjects during the year previous to the test, it seemed desirable to make a further comparison of the results obtained by the administration of codliver oil as a supplement to the home dietary. Accordingly, a comparison has been made between the hours of absence of each group during the year of the experiment with the hours of absence of the same individuals during the corresponding period of the year previous when no cod-liver oil was given as a supplement to the home dietary. These data are assembled in Table 111. TABLE111. HOVRSOF ABSENCEPER PERSON COD-LIVER OIL GROLT CONTROL GROUP 1930 1931 1930 1931 Hours Hours Hours Hours 16.3 9.8 11.2 7.5 27.4 26.3 16.9 43.8 18.5 29.6 30.4 22.0 61.4 43.3 2.6 26.0 40.2 24.2 16.8 38.5 12.4 7.2 6.3 7.0 Averages 2 0 . 4 12.8 17.4 25.1 a Weighted average, unequal number of subjects per room.
ROOM
The number of hours of absence per person during the experiment was 12.8 for the cod-liver oil group and 25.1 for the control group. I n other words, the subjects of the cod-liver oil group were absent during the period of the experiment only half as many hours as the subjects of the control group. WHOHADNo COLDSDURINQ EXPERIMENT During the previous year when the diet was not suppleTABLE I. SUBJECTS mented with cod-liver oil, the hours of absence were 20.4 for COD-LIVER OIL GROUP CONTROL ROOM Subjects Per cent Subjects Per cent the cod-liver oil group and 17.4 for the control group. 46.3 4 7.5 1 31 Considered from another angle, the members of the cod50.0 4 44.4 2 9 81.8 9 75.0 3 9 liver oil group showed a decrease of 40 per cent in lost time 43.8 8 53.3 4 7 while receiving cod-liver oil as a supplement to their home 61.4 10 58.8 5 27 31.8 6 19 65.5 dietary, .whereas members of the control group were absent -7 __ 42 32.8 144 per cent as many hours during the experiment as during the corresponding period the previous year. From these data It is interesting to note that 102 members of the cod-liver it would appear that feeding a vitamin-rich material as a oil group and 42 members of the control group did not de- supplement to the home dietary materially reduced the velop colds during the experiment. For the purpose of com- economic loss to employer and employee occasioned by lost parison, however, these data have been reduced to a percent- time of industrial workers. age basis. A consideration of the values 55.1 per cent for the cod-liver oil group and 32.8 per cent for the control group LITERATURE CITED reveals a decided difference in the occurrence of colds, for (1) Ackert, J. E., Fisher, M. L., and Zimmerman, N. B., J . Pnrasitol., 13, No. 3, Abstract (1927); Ackert, J. E., McIlvaine, M . 67.2 per cent of the controls developed colds during the exF , and Crawford, K’.Z , Am. J . Hug., 13, 3 2 0 (1931). periment whereas only 44.9 per cent of the cod-liver oil group (2) Block, C. E., Am. J. Diseases Children, 27, 139 (1924). developed colds during the same period. 4, 3 2 3 (3) Boynton, L. C., and Bradford, W. L., J . ,\Writion,
LOSTTIMEDURING EXPERIMENT Lost time constitutes an important factor in management and in production costs in industrial concerns. Frequently lost time means a cessation of income for the employee, and it always means a disruption of the normal plant routine. Accordingly, it was of particular interest to collect data concerning the amount of time lost by the different groups under observation. These data arranged by rooms and by groups are reported in Table 11.
(1931).
(4) Brundage, D. K., Pub. Health Repts., Reprint 1142 (1927). ( 5 ) Brundage, D. K., J . Ind. Hyg., 12, 338 (1930). (6) Cramer, W., Brit. J . EzptE. Path., 3, 298 (1922). (7) Daniels, A. L., Armstrong, M. E., and Hutton, M. K., J . Am. M e d . Assoc., 81, 8 2 8 (1923). (8) Dean, L. W., Ibid., 85, 317 (1923). (9) Emerson, W. R. P., “Diagnosis of Health,” Appleton, 1930. (10) Goldblatt, H., and Benischek, M., J . Erptl. M e d . , 46, 699 (1927). (11) Green, H. N., and Mellanby, E., Brit. M e d . J., 2, 691 (1928). (12) Macy, I. G., Outhouse, J., Long, M. L., and Graham, A., J . BioE. Chem., 73, 133 (1927).
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I N D U S T R I A L A N D E N G I N E E 11 1 N G C H E 11 I S T H Y
(13) Mellanby, E., and Green, H. Ti., Brit. .Wed. J . , 1, 984 (1929). (14) Metropolitan Life Insurance Co., S t a t i s t i d Bull. 4, 1923. (15) Mills, 8.B., "Extent of Illness and of Physical and Mental Defects Prevailing in the United States," Committee on Cost of Medical Care, Washington, D. C., 1929. (16) Osborne, T. B., and Mendel, L. B., Am. J. Physiol., 69, 543 (1924). (17) Pharmacopeia of the United State?, 10th Decennial Rwision, Lippincott, 1926. (18) Prather, E. O., Selson, M.,and Bliss, A. R., Am. J . Diseases Children, 42. 52 (1931). (19) Sherman, H. C., "Chemistry of Food and Sut,rition," Macmillan, 1926.
v01. 24, No. 9
(20) Sherman, H. C., and Burtis, 11.P., Proc. .Soc. E.@. B i d . M e d . , 25, 649 (19%). (21) Sherman, H. C., and MacLcod, F. L., J . I n s . Chem. Soc., 47 1658 (1925). (22) Shurley, B. R., and Turner, R. G., J . Am. M e d . Bssoc., 94, 539 (1930). (23) Sydenstricker, E., Pub. Health Repts., Reprint 1172 (1927). (24) Turner, R. G.. J . Infectious Diseases, 45, 208 (1929): Proc. SOC. Erptl. B i d . S l e d . , 26, 233 (192s). (25) Werkman, C. H., J . Infectious Diseases, 32, 255 (1923). (26) Tudkin, A M., J . Am. -\fed. .4sSoC., 79, 2206 (1922). RECEIVED February 3, 1932
Glycerol Viscosity Tables 1 1 . 4 ~ 1 ~L.0 ~ SHEELY,Armour
N
OTWITHSTAKDING some statements in the literature to the effect that glycerol and its aqueous solutions are not entirely suitable liquids for use as viscosity standards in calibrating technical viscometers, these solutions have come into common use for this purpose. The principal objection offered against them lies in the fact that solutions above approximately 85 per cent glycerol are hygroscopic, whereas those below this concentration give up water when evposed to average humidity conditions. Evperience has shown that these properties do not offer serious difficulties if the facts are recognized and precautions taken to obviate changes in concentration on these accounts. The principal points in favor of their use for calibrating purpose are the ready availability in pure form, wide range of viscosities, and ease of standardization as to glycerol content; c. P. glycerol of exceptionally high purity is available on the present market in concentrations from 95 to 99 per cent. The difference represents largely water, there being usually less than 0.01 per cent foreign impurities present in the c. P. grade. Consequently, the range of viscosities obtainable upon the more highly concentrated grade and its aqueous solutions is from 12.00 to 0.01 poises. By means of an accurate specific gravity determination the percentage glycerol concentration can be determined within *0.02 per cent. With this information a t hand, a table showing the absolute viscosities of varying concentrations would complete the information necessary for the purpose. The literature contains several references to the viscosity of glycerol; the data of Archbutt and Deeley (1) and of Herz and Wegner (8) are perhaps the most widely quoted and used. The former authors worked with an instrument of their own design and determined absolute values for viscosities a t 20" C. for eight concentrations of glycerol from approximately 40 to 97 per cent. These, together with their value for water, were used in constructing a table of viscosities corresponding to specific gravities from 1.000 to 1.260 a t 20"/20° C. While the data of these authors no doubt represent the best a t present available, they are of questionable value for accurate calibrating purposes, principally because of the fact that only eight points of the viscosity curve were determined, thus necessitating interpolation between widely separated points. Moreover, the purity of the original glycerol which was purchased in 1896 would be open to question, since methods of glycerol manufacture a t that time were quite crude when compared with present-day equipment and processes. The purpose of this paper was to determine accurately the concentration-viscosity curve of solutions of commercial c. P.
Soap Works, Chicago, Ill. glycerol of highest purity over a limited room-temperature range-namely, 20" to 30" C.-and to show a comparison with the published values. A secondary purpose of the investigation was to determine sufficient data in the higher concentration range to make possible the accurate evaluation of the percentage glycerol concentration from the viscosity value. As a matter of fact, the choice of temperatures noted in the table of viscosities was made for the purpose of constructing an accurate temperature-correction table by means of which it would be possible to correct viscosity values made a t any temperature between 20" and 30" C. to the nearest determined curve, and to read off directly the corresponding glycerol concentration. Such a table would be of considerable practical value in glycerol manufacture, since concentrations of 93 to 99.5 per cent are those most often dealt with in the glycerol refinery. The viscosity in this range changes very rapidly with Concentration, and preliminary tests have indicated that evaluation by such a method is quite as practical, somewhat shorter, and quite as accurate as the usual specific gravity determination for evaluating glycerol concentration. Brief mention should be made of the work of other authors on the subject. Hera and Wegner (8) made use of four Ostwald viscometers and constructed a temperature-concentration-viscosity table from 10 to 92 per cent glycerol a t temperatures from 10" to 80" C. Their results are given in absolute units and are based on their own density table for glycerol concentration ( 7 ) . Kellner ( I O ) determined the relative viscoiities of glycerol solutions prepared from a "fermentation" glycerol by distillation, from 75 to 100 per cent glycerol (basis Gerlach specific gravity table, 15"/15" C,). He used the Engler viscometer a t 24" C. and expressed his results in Engler units compared to water a t the same temperature. He pointed out the possibility of the viscosity being used as a quality control in glycerol production and also as an index of its concentration. Jones (9) in some studies of the falling ball method of viscosity measurement published some meager data on the viscosity of glycerol, but his figures should be considered only approximate, as they are not based on sufficiently accurate specific gravities. Cocks ( 5 ) has compiled considerable data on this subject, supplementing these with many of his own determinations on a S o . 1 Redwood viscometer, using the Higgins equation for calculating the absolute values. He extended the Her2 and Wegner table up to 99.2 per cent glycerol and 100" C. for the higher concentrations. Other authors on this subject include Muller ( I I ) , Schottner (IZ),and Darke and Lewis ( 0 ) .
