Document O1kDE8peYG7e3V36DVzBw0xyw

BRITISH PLAINTIFF'S EXHIBIT I TPI-687 JOURNAL OF INDUSTRIAL MEDICINE VOLUME TWO 1945 EDITED BY DONALD HUNTER WITH THE ASSISTANCE OF DONALD STEWART LONDON BRITISH MEDICAL ASSOCIATION TAVISTOCK SQUARE, W.C.I 15$ZO rivF son read a paper on ' The Rc. rsons in Industry.' : the successful resettkiiu n ,n . , .) The attitude of employ un K ('``--Heir foremen, who e.n <j,, s: so too is the amiuj,. is .. grow weary of the Ini^. ke all the difference--and tlK. I health and environmental conditions in the af the disabled men themselves ompensation in cases of miurv ! IRON FOUNDRY .settlement. Again, light work I hich a disabled man was em- acity may be a legitimate, and ry, method of restoring him io BY afeguards are necessary to pre in this connexion and to sec G. F. KEATINGE and N. M. POTTER -d to drift along indefinitely in ., able to do something better, From the Medical Department, The Butterley Company, Derby disabled man is so much in the t makes him even a little more to his prospect of successful ore important to secure the This survey is largely based on experience gained fixed on the moulding machine and are filled with in the foundries of the Butterley Company. sand or loam from an overhead hopper. The sand of physical and psychological Number I Foundry produces small, medium and must be under rigid control and may possess either ng, the longer disability has isfactory the prognosis; and Experience in Denmark has arely an economic proposition light castings on a semi-mechanized basis and very light castings on a fully mechanized unit, while Number 2 Foundry makes large castings of a a natural bond or have added to it a synthetic bonding substance (both of which contain a pro portion of alumina) the latter having an addition in new work of a disabled man general nature. More than 200 workers are of coal dust to give skin finish. After the box is and recent experience in this that, in general, younger men ng for new employment. The he set afoot as early as possible, / employed in the foundries, of whom 14 are engaged in fettling, 50 in moulding, 40 in core-making and the remainder in other work. Some 12 women are filled with sand it is rammed hard mechanically and then turned upside down, so that the impression of the pattern is now uppermost. ence of Denmark is worthy of also employed in the fettling of small castings. ions may be weighty. Somenet in which the disabled man The work done is representative of many branches of ironfounding; the building and general environ t scope for new employment ment are of a kind very usual in the industry and lieved heavy industry in it or for this reason it is felt that conclusions based on ion with limited facilities for , it is not easy to find suitable experience of these foundries can lay some claim some areas of Lanarkshire, or v to give a picture of the ironfounding industry as a ; parts of the Highlands. The ' whole. nc of the disabled man is of I v -ossibility of harnessing | : sground as he may have ce, a man may be unable to Foundry Methods Ironfounding is the process of casting in iron by worker, but if he can be given running molten metal into a mould of the required crcial training and this related f the woodworking industry, ry valuable agent, despite his shape taken in sand or loam. The material forming ' the mould is caused to take up the appropriate of serious disability it is often shape by means of a pattern which can be regarded ire the return of the disabled ironment with which he is 0 the factory in which he was as a ` positive the mould a ` negative ' and the casting itself a ` positive '. There is a considerable difference in the technique of manufacture used for nany difficulties, with medical, | moulding in sand and loam so it will be convenient aspects closely interwoven. i to consider them separately. avy; some that long travelling I >ng working shift is too much , ulty in obtaining tools; some Sand Moulding lg suitable clothing. Many I This method of moulding is used to make all e wages they are able to earn responsibilities. Many chafe some pension delays. Mans 1 suitable house: a disabled smaller castings, and as they arc often required to be produced in large numbers, mechanized systems are much in use for this type of work. A mech nuch difficulty in making his anized unit comprises sand preparing plant (see . of a high tenement house as ~o be successful the approach ity must be along individual 1 must be kept in view until , fig. 7), moulding machines (sec figs. I and 8), mould conveyors and ' knock out ' (see fig. 10). The pat terns are made of wood, plaster or metal, and it is he is indeed settled in work essential that they be made as perfect as possible because the labour employed is chiefly unskilled. The moulds are usually made in two sections in moulding ' boxes ' which, however, are not boxes m the true sense of the word as they possess sides only and have neither floor nor roof. The moulding boxes are placed on top of the pattern which is Fig. 1....Machine moulding method. A. Oicrheud l'tip;h`/ H. Main i<<lninn upright. C. Moulding box with pattern l). (<mt/ilc ' ed iudt numid Both sections of the mould are dealt with in this manner, but it is obvious that many internal spaces cannot be formed by a pattern directly in the sand and provision for these has to be made by means or ' cores ' which are inserted after the pattern has been removed. Cores are generally made of a silica sand bonded with molasses and linseed oil, or a proprietary brand of binder which may be had in either a semi-solid or liquid state. All cores are baked in either a fixed or continuous stove which may be either coke or gas fired. K 126 BRITISH JOURNAL OF INDUSTRIAL MEDICINE Cores, if required, are inserted in the appropriate plaees and one-half moulding box is turned so that the impression of the pattern in the sand faces downwards and the two sections are then approxi mated. The mould is now complete and awaits the pouring of the molten metal through a special aperture left for the purpose known as the pouring basin. The metal is melted in a cupola or forced draught furnace and when ready it is run into special ladles by which it is transported to the moulds into which it is to be poured. In addition to the pouring basin, exits known as ' risers ' are sometimes added to enable the gases to escape on the introduction of . the molten metal. The moulds are now placed on the conveyor after which the metal is poured and the boxes are moved mechanically to the ` knock-out ', the point at which the contents are to be removed from the box by knocking or hammering by hand. In the course of the journey, while cooling is taking place and the metal is becoming solidified, a good deal of fume is given off, chiefly due to the burning of the core oil. There is also a considerable amount of dust and fume associated with the knock-out. This takes place over a grid through which the used sand is collected on to a conveyor belt running under the floor of the shop and by which it is carried to elevators (see fig. 7). These in their turn take the sand to the mixing plant where it receives an appro priate amount of fresh sand and is then again ready for use. After having been knocked out the casting may still retain the pouring basin and possible ' risers ' and these, having served their purpose, have to be removed as well as any cores and sand which may remain adherent to it. Excrescences of metal on the surface of the casting such as appear at the point of junction of the two halves of the moulding box have also to be dealt with and this is done by means of a pneumatic chisel or by a mechanized appliance, such as a nimbler or wheelabrator. The essential feature of both these pieces of apparatus is to cause the castings to be kept in motion while at the same time their surfaces are abraded by small shot or rather larger pieces of metal placed inside the machine for this purpose. The cleaning of the castings is completed on a grinding wheel, either fixed or movable (see fig. 12). Hand manufacture of smaller castings follows essentially similar lines, but it is a slower process and all gradations exist from completely hand manufactured articles through a semi-mechanized system to the highly mechanized unit already described. Sand moulding is also used for the manufacture of huge castings, but the principle involved is the same, namely, pattern mould>casting, although, of course, a large casting cannot be made in a ' box ' but needs special construction on the foundry floor. In both sand moulding and loam moulding for the making of laige castings, the moulds and cores must be dried, and blacked with a mineral blacking. ' Loam Moulding Loam, a wet and plastic sand mixture, is employed for making the moulds required for some large heavy work. The building up of the mould starts from a castiron bottom plate upon which bricks are placed and 1 bedded ' to each other with wet or putty loam in order to give the rough outline desired. When this has been done, wet loam is applied to the face and the true contour of the mould is then obtained by the use of a strickle or shaping board. The strickle board is constructed of wood in the exact shape needed and works from a spindle set up in the centre of the mould. In most cases the core is made in a similar manner (see fig. 2). Pouring of the metal is carried out as has already been described under sand moulding, but the cleaning of large castings is a difficult process. They can be placed in a sand blasting chamber which is sealed off from the body of the shop and in which an operator provided with suitable pro tective clothing, including an air helmet, directs a current of compressed air and sand on to the casting. This method is not practicable in all cases, as for example the very large casting, and until recently it has only been possible to carry out the fettling in these cases by hand or with the help of pneumatic chisels and sw ing frame grinders. A new method known as hydro-blasting has, however, been devised in the United States of America, by means of which a high velocity jet of sand and water is projected on to the castings, thereby removing moulding material, cores and scale (see fig. 13). In addition the method keeps the atmosphere free from dust. If these claims are substantiated, this method may be one important solution of the dust problems in this industry. Environmental Studies Heating and General Ventilation Table 1 shows the results of the readings taken with the kata thermometer (dry bulb) as well as HEALTH AND EN recordings of the whirling findings show the ventilatie the cooling power satisfacto tying done so far as it is po .Imp in which it is obviou die heat, from the nature ot eanii 'i be regarded as unsat Taih.i SURVEY OF THE EFFICll HEATING AND \ Position 1 tin Iv Date of Hour of i i eadmg reading f (Hindi-* No. 2 Ml.tckstone Bed 1 (Hindi v No. 1 ( >ie -hop . . ( i>rc xtiop .. 1 tuindrv No. 1 Sew fettling shop - 26 2.43 26 2 43 26 2 41 26 2 4 l IS 45 IS 4S IS 1 45 hi 10 15 10 30 ! 0 50 1115 14 U) 14 45 -4 I 5 00 4 Fume*- The fumes in the foundry the burning of bonding sub sand such as linseed oil, dex Those given off by the res although the fumes dcrivei rather acrid; in general, he Ire innocuous, except those which may possibly be carci. Dust Ha/ It has long been known workers are subjected to a and many investigations hav the past, notably in Austral a very limited investigation i was possible in this survey, b hy time and availability of a however, may form a useful compiehensive study, and ll of sonic value to subsequent In order that an estimau potential danger of dust inf Inal operation, precise know following four factors'. (1) The average concei the air breathed by the vv tion. (2) The approximate t spends in this environmen (3) The chemical com] du\l. (4) The size frequencic inhaled. Ii'chnii|ue *i :>Hecuon of Samples.-- I 10 the method to be adopted ind blacked with a nmeraij HEALTH AND ENVIRONMENTAL CONDITIONS IN THE IRON FOUNDRY 127 i Moulding i' i d mixture, is employed I Js .cquired for some iargt- ' he mould starts from a east. 1 in which bricks arc placed j uher with wet or putty loam ugh outline desired. When ( ; loam is applied to the face ( ' the mould is then obtained le or shaping board. The ucted of wood in the exact vs from a spindle set up in !. In most cases the core is cr (see tig. 2). I recordings of the whirling psychrometer. These findings show the ventilation to be adequate and (hc cooling power satisfactory for the type of work being done so far as it is possible to assess. For a shop in wffiich it is obviously difficult to regulate the heat, from the nature of the work, these figures cannot be regarded as unsatisfactory. Tabu t SURVEY OF THE EFFICIENCY OF FOUNDRY HEATING AND VENTILATION -- Position Tem perature assesses, by whirling Date of Hour of psychroleading reading meter Wet Dry bulb bulb Cooling by kata thermo- Di \ lulb Air velocity (feel per minute) Head Floor level level Foundry No. 2 Blacksione Bed Core shop . . Foundry No. 1 New fettling shop 26.2.4.1 26 2 4.1 26 2 43 26 2 43 18 1 45 18 1 45 18 1 45 10 15 10 30 10-50 1115 14 30 14 45 15 00 53 53 53 s2 50 47 47 55 1 1 0 9 5 58 8 0 8 0 62 8 5 -- 58 10 0 8 0 52 12-75 10 0 52 16 0 14 0 50 10 0 110 100 4(1 65 90 120 220 40 moulding method. ' bedded' together unit iwv Strickle cr shaping board. Fumes The fumes in the foundry are derived chiefly from the burning of bonding substances used in the core sand such as linseed oil, dextrine, resins or tar oils. Those given off by the resins are not unpleasant although the fumes derived from linseed oil are rather acrid; in general, however, they appear to be innocuous, except those produced from tar oils, which may possibly be carcinogenic. is carried out as has already j sand moulding, but the | ings is a difficult process. i a sand blasting chamber 1 t the body of the shop and provided with suitable pro ng an air helmet, directs a air and sand on to the s not practicable in all cases, ry large casting, and until n possible to carry out the v hand or with the help of , ving frame grinders. 1 wn as hydro-blasting has. in the United States of .\hich a high velocity jet of 'jeeted on to the castings, tiding material, cores and Jition the method keep-- the dust. If these claims arc iod may be one impoiiam slems in this industry. | i va At. Stldii.s eneral Ventilation suits of the readings taken .eter (dry bulb) as well a- Dust Hazard It has long been known that certain foundry workers are subjected to abnormal dust hazards and many investigations have been carried out in the past, notably in Australia and America. Only a very limited investigation of the dust environment was possible in this survey, the work being restricted by time and availability of apparatus. The results, however, may form a useful introduction to a more comprehensive study, and the experience gained be of some value to subsequent workers in the subject. In order that an estimate may be made of the potential danger of dust inhaled during any indus trial operation, precise know'ledge is required of the following four factors; (1) The average concentration of the dust in the air breathed by the worker during the opera tion. (2) The approximate time which the worker spends in this environment. (3) The chemical composition of the inhaled dust. (4) The size frequencies of the dust particles inhaled. Technique (u) Collection of Samples. -In making any decision as to the method to be adopted to give this information. the investigator mast consider the various methods which he may have available, and assess each from a practical standpoint. Two factors must be emphasized. It is well known that the dust concentrations of a dusty occupation vary enormously so that ` spot ' samples are of very limited utility. Secondly, it is known that the technique adopted will affect the magnitude of the estimates. Thus, results obtained with the Owens jet dust counter will generally be considerably less than those obtained with the Midget Impmger. Generally, the correlation between any two methods is very poor indeed. It is necessary, therefore, in presenting the results of an investigation that the technique employed should be rigidly defined. In order that an average sample may be obtained over a lengthy period, and be subsequently submitted to analysis, two general methods are available, the Impinger and nitration. American practice Iras long favoured the former. Two criticisms may be advanced against the Impinger: transport and transfer of a liquid medium is inconvenient in a works; and secondly, the high speed at which the particles impinge on the base of the tube may fracture the larger particles, thus giving an erron eously high number when the particles are counted. The Briscoe crystal tiller overcomes these difficulties. The dust enters the filter at a low speed and may be recovered easily from the crystal bed and prepared for particle counts or analysis. The microscope slide may be prepared of a correct density to facilitate counting, a difficult procedure when using the Konimeter or similar spot methods. Although concentrations may amount to millions of particles per cubic foot, the actual weight of dust in suspension is so small that a micro balance is practically essential for the determination of mass con centration and chemical analysis. Unfortunately we were unable to obtain such a balance in the time available, and the ordinary analytical balance was of a type unsuitable for adaptation to micro weighing. All weighings are limited to an accuracy of 02 mg., this being determined over a scries of repeated investi gations using a carefully controlled technique. So that maximum quantities of dust should be available for analysis, samples Nos. 1-7 were taken with a rotary hand pump attached to a large Briscoe filter. Five subsequent samples w'ere taken with hand syringe (capacity 00055 cu. ft.) coupled to a simple micro crystal filter, a number of which may be carried about ready loaded in a small box. A tubular extension was fitted to the filter, and the pump operated at a speed sufficient to draw in falling particles smaller than 35 microns. ib) Chemical Analysis.-- In view of the small amounts of dust available for analysis only a very limited empirical procedure is practicable. A portion of the collected dust was placed in u small platinum crucible made from foil and subjected to three processes in the crucible. (1) Ignition at 700 C. to determine the percentage of combustible matter. (2) Extraction with dilute hydro chloric acid to give the percentage of soluble material (mainly iron). (3) Evaporation with hydrofluoric acid and subsequent ignition to constant weight to remove the total silica. The greater part of the total silica would, in fact, be free silica in the samples examined. The residues of all samples were then bulked and the per centage of alumina determined after fusion with sodium carbonate. Obviously the accuracy is dependent on the number of operations involved and the weight of the available samples. Without a micro balance the accuracy obtain able is low and since the analysis refers to all particles this may not be the same for all size frequencies. (c) Microscopic Methods. -The method adopted for the determination of the number of particles and the size frequency of the dust has been described in some detail by Lowrie Fairs (1944). The portion of the collected dust not used in chemical analysis was agitated in alcohol. The dispersed suspension was then further agitated by means of air blown from a pipette. A drop on the end of the pipette was then transferred to a 128 BRITISH JOURNAL OF INDUSTRIAL MEDICINE haemocytometer cell and after allowing the sample to dry, the dust particles were counted and sized by means of a Patterson graticule in the eye-piece of the micro scope. Having established the relative frequency of occurrence of each size of particle, a weighted average may be calculated assuming that the particles weigh the same as a cube of the same dimensions, the specific gravity being an average calculated for the dust. This has been shown to be approximately true. The number of particles present in the original sample in each size range may then be calculated. The method has two disadvantages. It is by no means an easy task to prepare an even deposit on a slide truly representative of the original dust. The total weight of the dust on the slide will only be a fraction of a milligramme. Again, only a small fraction of this deposit will be sized against the graticule. Secondly, the greatest weight of the dust will be in the large particles which are numerically insignificant. One particle 70 microns in diameter is equivalent in weight to 343,000 particles of one micron. Great care must be exercised in order that the propor tion of large particles may be estimated correctly. Between 2000 and 3000 particles were sized for each sample. The process is, therefore, a laborious pro cedure. Furthermore, the microscope itself has limita tions. The microscope available was a Watson ` Edinburgh Student' lined with mechanical stage and substage condenser (NA 1-0). A 16-mm. objective combined with a y.l Holos eye-piece incorporating a Patterson graticule, was used for measuring part'cles in the range 10-70 microns. Particles below 10 microns in size were measured with a 4-mm. apochromatic objective. A blue light filter was incorporated to facilitate the observation of the smallest particles. The resolving power of a microscope depends largely on the wavelength of the light source and the numerical aperture of the objective and substage condenser. Particles much below 0-5 microns in size cannot be discriminated with the ap paratus. Since the numerical proportion of particles below I -5 microns in size is very large it is apparent that microscope counts are subject to large variations according to the apparatus available and possibly also to the observer, since particles near the visible limit are exceedingly difficult to define. In spite of the limitations outlined above, and the development of other micro methods for the determination of size frequency and total surface area, the microscope is still the most positive method available and probably the most satis factory. Location of Samples All samples were taken from a position near to the operative's mouth unless otherwise stated. Generally the filter was inverted and the air intake speed adjusted so that only particles less than 40 microns in size would be included in the sample. In actual practice particles much larger than this are projected at high speed by certain processes and are retained by the filter. In the case of two samples (Nos. I and 7| the proportion was so excessive that particles in excess of 70 microns were removed by sieving the dust samples on a micro sieve. If more than one operator was engaged on similar work the sample was divided between the various workers. Samples generally took about one hour to collect. Sample \ii I. Medium Fettlmgs. The site was in the old f etllmg Shop lor the treatment of castings up to about 3 cut Over a period of more than one hour three feltleis were sampled. The leltlers used eompiessed-air picks. It was noticed that the worst atmo spheric conditions were prevalent when cleaning off the dust by the process of ` blowing oil" with the nozzle. In addition, dust was blown into the operator's face by ' the exhaust when cleaning the inside of castings. The actual fettling may occupy one-third to one-half of the worker's time. A fair current of air was moving across the shop. Sample No. 2. The general body of No. I Foundry. In order to collect a maximum amount of dust for analysis the filter was placed facing upwards for this sample. No machinery was nearer than 12 ft. The location was away from, but surrounded by a variety of foundry processes. These included medium and fine fettling, pneumatic and spray -type mould fillings, shaking out of moulds, wheelabrating, metal pouring and rumbling. Sampling was continued for 35 minutes. Sample No. 3. Mould Filling. This sample was taken at the breathing level of two mould fillers during the actual operation of the pneumatic filling. Dusting, brushing and blowing off' processes were not included in the sample although residual pollution from these sources may still have persisted. This sample, therefore, only refers to the actual filling of the mould and tamping off. The moulds were of moderate size and took from 10 to 14 seconds to fill. Not more than one-seventh of the worker's time was spent on this operation. Sample No. 4. The ` Knock out'. This sample was taken during the emptying of the moulds after partial cooling. The moulding material was emptied over a grating. Fumes were excessive, but this did not appear to be a particularly dusty occupation. One operator possibly spent one-third to one-half of the working shift actually knocking out the moulds. Sample No. 5. Defective Wheelabrator. The air borne dust was sampled about four feet from the wheela-. brator. A considerable dust cloud was carried towards No. 1 Foundry during operation. This machine is working for about one-third of the shift and although workers were not in the immediate vicinity, dust was carried towards No. 1 Foundry and in the path of several workers. The machine is due for immediate replace ment. Sample No. 6. Small Fettlings. The small fettlings are carried out in a shop adjoining No. I Foundry. It is a new shop and is cleaned regularly. The conditions compare very favourably with the rest of the foundry as regards house-keeping. One-half of the sample was taken from the breathing level of an operator working a Spenser Duplex high-speed grinder. This operator was the only one observed to be wearing a mask. The shop is used exclusively for grinding off excess metal from light castings. The second half of the sample was obtained during the operation of a small pneumatic carborundum high-speed grinder. There were several of these machines in operation and none were fitted with dedusting devices. The compressed air exhaust did not appear to aggravate the dust nuisance and con ditions appeared relatively clear in the shop. Probably operators are grinding about three-quarters of the shift. Sample No. 7. Large Fettling. This work was car ried out near the closed end of one shop. Castings were very large (up to 10 tons) and fettling occupies probably two-thirds of the shift. The sample covered two fettlers cleaning three large castings. Much dust was observed to be dispersed into the air during the blow-off period. Air conditions were comparatively sialic in this part of the foundry. Sample No. 8. Core Shop. This shop is an annexe to No. 1 Foundry, and as with Sample No. 6 conditions are no doubt improved by this arrangement. The mixture, which is hand filled by girls, consists of sea sand, ' Cordex ' (an artificial bonding substance), and linseed oil. Sixteen workers were employed and the work was practically continuous. All these workers I contributed to the sample. Sample No. 9. General Body, No. I I oundry. The sample was taken in about lhe middle of No. 1 FoundryImmediately opposite was a large opening into No. a Foundry. A 'Slinger', working about 20 per cent, ol the sampling time, was situated 10 ft. away. HEALTH AND EA Sample No. 10. General IT dimpling position was 37 yd. 1 I oundry, and was situated ii large moulds which were in tl Large moulds were being cons Sample No. II. General Sampling position was 37 ya the foundry. A large mould the position and this part of t1 with various operations in the Sample No. 12. General B< sample was taken in the ceni 'Lately opposite a large anneah Discussion of Results The mass concentration > in Table 2 and the chcmic Tahli: MASS CONCFNTRATK DUST AT BREATI Sample No. Location or occupation Wt. du(niy 1* Medium-sized 71 fettlings . . Main Body, No. 1 Foundry 19 ) Pneumatic mould filling 23- 4 Shaking-out . . 15 5 Defective wheelabrator 31 6 Small fettling .. 14 7* Large fettling .. 48 8t Core shop . . 1 9f Main Body, No. 1 Foundry 1 lot Main Body, No. 1 Foundry 1i Ilf Mam Body, No. 2 Foundry T 12 F Main Body, No. 2 Foundry 1 , Tahli Oil MICAL ANALYSIS O Sample No. Wt. of sample analysed | fmg.)........................ I 52 IVr cent, loss on ignition (combustible matter) . . Id I'cr cent, soluble in hydro chloric acid (mainly 'ton, etc.) . . .. II her cent, total silica (loss W|(h hydrofluoric acid) ! 67 j'er cent, residue . . . . i I 2 I'cr cent, alumina (AI.O.,) I m residue . . . . i I he weight distribution and ; feu cubic foot for a limited r. * ' i dimples 1 and 7 dust over 7' 1 1 1 - 'si/'.e sieve. Including ih is t - - md 5-22 mg. per cu It. respc ' cs taken with micro Idler an- ' blowing oil" wilh th,' own into the operator'^ mg the inside of c.tstin i' Ae-third to one-ha . of air was movtn O/I, -v Is. .1^ JU'ls, .icneral body of No. I Foundr. maximum amount of dust r,,. placed facing upwards for n)K was nearer than 12 ft. | , . but surrounded by a varieu m ese included medium and nnc pray-l>pe mould fillings, shaking kihrating, metal pouring ,lnj is continued for 35 minutes, aid Filling. This sample w4, evel of two mould fillers dunn.' the pneumatic filling. Dustin- f processes were not included n. esidual pollution from the-, rsisted. This sample, therel'ou. tilling of the mould and lumping if moderate size and took 'mm Not more than one-seur.l, oi ent on this operation. Knock out '. This sample u4s ing of the moulds after p,,nu| material was emptied over j cessive, but this did not appeal sly occupation. One operato; to one-half of the W'orking shut e moulds. etive Wheelabrator. The au- ibout four feet from the wheeludust cloud was carried towards : operation. This machine is third of the shift and although e immediate vicinity, dust was undry and in the path of several is due for immediate replace- ' 17 ~ 'ings. The small fettlings ning No. 1 Foundry. Ii it......s-egularly. The conditions with the rest of the found > as One-half of the sample was g level of an operator woihmg speed grinder. This opetator ed to be wearing a mask. The for grinding off excess metal j second half of the sample was oration of a small pneum.uk I grinder. There were several peration and none were titled The compressed air exhaust ale the dust nuisance and conly dear in the shop. Proh.thb tout three-quarters of the shift. Fettling. This work was caind of one shop. Castings were i and fettling occupies prohahh Die sample covered two fettle's ngs. Much dust was observed air during the hlow-olf period parattvely static in this pan ot I | t I | j . ' ' I I / ' shop. This shop is an a"'vv s with Sample No. 6 cond !>' J by this arrangement, t'v tilled by girls, consists v . -c.t lieial bonding suhstaneet si rkers were employed am: . vnlinuous. All these vvoi,,:- l ' ,tl Body, No. I Found! y. I l the middle of No. I I-oiindi is a large opening into No working about 20 per cent, mated it) ft. away. Sample No. 10. General Body, No. I Foundry. The !>amp|ing position was 3V yd. from the top end of No. I foundry, and was situated in the space between two large moulds which were in the process of being filled. Large moulds were being constructed nearby. Sample No. II. General Body, No, 2 Foundry, jjmpltng position was 37 yards from the top end of ihe foundry. A large mould was being filled close by the position and this part of the foundry was very busy with various operations in the vicinity. Sample No. 12, General Body, No. 2 Foundry. The 'sample was taken in the centre of the foundry imme diately opposite a large annealing oven. Discussion of Results The mass concentration of each sample is given in Table 2 and the chemical analysis in Table 3. Table 2 MASS CONCENTRATION OF AIRBORNE DUST AT BREATHING HEIGHT Sample No. Location or occupation Wl.of Vol. air Mg. Mg. dust sampled per per cu. (mg.) (eu. ft.) cu. ft. metre 1* Medium-sized 7L7 20-74 3-46 122-1 fettlings .. 2 Main Body, No. 1 Foundrv 19-2 1600 1-20 42-4 3 Pneumatic mould filling 23-6 11 20 2-11 74-5 4 Shaking-out . . 15 6 13-39 116 40-9 5 Defective wheelabrator 31-6 918 3-44 121-4 6 Small fettling . . 14-3 15-39 0-93 32-8 7* Large fettling . . 48-2 10-00 4-82 1700 8t Core shop . . 1 -3 5-55 0-23 8-2 9t Main Body, No. 1 Foundry 1-7 5-55 0 31 10-8 lot Main Body, No. 1 Foundrv 2-9 5-55 0-52 18-4 lit Main Body, No. 2 Foundrv 2-2 5-55 0-40 140 12t Main Body, No. 2 Foundry 2-2 5-55 0-40 140 Table 3 CHEMICAL ANALYSIS OF AIRBORNE DUST Sample No. i 7 3+4 2 Wt. of sample analysed (mg.)........................ 52-8 29-8 140 8-8 Per cent, loss on ignition (combustible matter) . . 10 0 80 210 410 Per cent, soluble in hydro chloric acid Imamlv iron, etc.) . . . . 110 ISO 110 180 Per cent, total silica (loss with hydrofluoric acid) 67 0 68 0 500 200 Per cent, residue . . . Per cent, alumina (Al.O,) 120 60 ..... .-1--8-0-- 21 -0 --- ----- ' in residue .. 30 The weight distribution and the number of particles per cubic foot for a limited range of si/e frequencies * From samples i and 7 du-0 over 70 microns in si/e was removed by a miero-si/e sieve. Including this oversize dust the concentrations ere 5'77 and 5'22 mg pci ui It respectively, t Samples taken v. uh micro niter and hand syringe. ! AMI I 4 Wj;i(,H7 DIS1 RIHUIION AND |A K f IC I IS 1*1 R ( UBK I'OOI I Ni mik k "i Par i k i i.s hr cum i < >< 11 Sample No Sp. gr (c lc > Med uni leu my 2 Genera 1 body .1 Pneu matic Idling s 65 1 2 4 2 4 4 Shake out 6i 7 Small Large teuliny fettling 2 4 4 () , 2 65 Size in microns >35 >20- <15 >6- -'20 Less than 6 , Total particles per cu ft. - 0 005 U 01 1 0 095 4 84 ; (Nun her of particles 0 002 0 004 0 002 0 0061 0 01 0 006 0 054 0 108 0 071 i 81 3 55 2 625 10') 0 0011 0 001 i 0 017| 2 27 ! 4 95 1-88 .1-67 2-704 2 11' 0 004 0 Oil 0 607 27 57 28 20 Total particles per c c. ' 17s 000 66 000 129-000 95 000 81 000 995 000 >35 >20- <15 >6- <<20 Less than 71 16 4 76 27 Wl KH 1 61-8 2V8 ; 120 24 I'l R ITS 1 . 60 0 59 1 21 5 22 9 11- 1 11 1 .1-2 4-7 51 9 28 9 27 5 11 > 15 8 I Z"1 6 4-8 | 12 2 l is shown in Tabic 4. The percentage weight under size for each particle size is graphed in fig. 3 and 3a, on a log-log scale. In order to show the relation ship between mass concentration and particle I Ij size rprourid-' c ; r in Migdcv ++ /es or aipropne foundry dus+ Fig. 3. ICC f J MK.kuNS ,i;r i+'/ESof airborne rcuuu,v dos'e Fig. 3a. 130 BRITISH JOURNAL OF INDUSTRIAL MTDUINT number per cubic fool a diagram has been prepared dig. 4 and 4a) showing die effect of exclusion of large particles on the mass concentration and particle cotint. The mass concentration shows at 36 r 4(jj CC 5 c<c o JO j 210 oo |,S 4 a 20" ;o ! a: s5 I 0 ^6 H 4 t -a 1d a I -Oi 00l 1=1I inCllDlS al: UAPTiClES PEiA^iON AND XCLUOES > 6 MlCPON PApTiClJ'cj bETv\EN MASS CONCENTPATiQN ^aQT'ClE NuWBh U Figs. 4 and 4a. once that the medium and large fettlers have the dustiest occupation. The defective wheelabrator is a large source of pollution, but this pollution does not appear to have affected conditions materially in the general body of the foundry. The vast majority of workers spend most of their time in the conditions revealed by samples taken from the general body of the foundry. These show a rather striking constancy when due allowance is made for sample No. 2 which included particles of all sizes. Conditions appear to be better in small shops such as the small fettling and core shop. Cleaner house keeping is possible in these circumstances and the effect is reflected in lower dust concentrations. The situation of these shops in annexes off the main foundry mitigates the effect of pollution from this source. Chemical analysis shows that the dust from medium and large fettling consists largely of silica panicles. This was confirmed by the microscope. Although it is impossible to identify very small particles it is reasonable to assume that these particles are similar in chemical composition to the large particles. The pollution in the general body of the foundry is definitely higher in combustible matter and lower in_silica content. The character of the airborne dust produced during the tilling of moulds and the shake out is intermediate between the extremes of large fettling and general body, but since the mass concentrations are much lower and the time spent by the operator in these occupations is much less the silica hazard is much lower than that of the fettlcr. Microscopic examination of the dusts shows that numerically 96-98 per cent, of the particles are less than 6 microns in size. The actual weight of this fraction may be less than 3 per cent, of the total weight of dust. Since the dust which may be retained by the lung tissue is above the resolving limit of the microscope and below 6 microns in size, it follows that mass concentrations without numerical counts cannot provide a true measure of the dust hazard unless special precautions are taken to exclude particles in excess of the upper size limit. This is strikingly illustrated by a comparison of samples Nos. 1 and 7 (fig. 4 and 4a). Including all particles, sample No. 1 gave a slightly higher concentration than sample No. 7. The particle count, however, showed that the hazard for the large fettler (No. 7, 995 particles per c.c.) was more than live times that of the medium fettler (No. 1, 175 particles per c.c.). The airborne dust from the latter source is much coarser than that produced from the former (fig. 3a). This may be due to the nature of the process although it seems likely that air conditions may be partly responsible. The medium fettler is often working on the inside of castings, and in this instance there was a definite ventilation current across the shop. Large par ticles projected from a process at high velocity are only partly deflected by air currents whereas small particles will tend to be carried away from the worker. If due allowance is made for the higher silica content of the air breathed by the large fettler, then the silica hazard of this worker is fifty times that of a worker in the general body of the foundry. Medium fettling represents a nine times greater hazard, and pneumatic mould filling and shaking out no more than five times. Owing to the relatively short time actually spent by the worker on these processes the dust hazard will be much less than is indicated above. Large particles of coal dust were prevalent in the air of the main body (sample No. 2) and in the samples from pneumatic filling and the shake out (Nos. 3 and 4). This last included many particles which were partly coked, and in view of the excessive fumes breathed by the worker the harmful effects of tar cannot be ignored. The sample from the small fettling shop consisted largely of iron and carbotundum particles, and the concentration would not appear to be excessive. Although the workers in the core shop are handling a sand mixture most of their time, the nature of the mixture with the linseed oil binding is such that air pollution from this source is very low indeed (sample No. 8). Micro samples from the main body of the foundries (Nos. 9, 10, 11 and 12) show that there is no excessive pollution in the foundry atmosphere judged by internal standards. In the routine control of atmospheric pollution such as that which exists in the foundry, measure ment of mass concentrations represents the simplest way of keeping a check on changing conditions. , I IIUAL I II AND EN I ie. 4 and 4a show very . panicles could be excluded :iaiton would also enable measured accurately. This lot samples which are m. velocity particles. The terr panicles falling in still air a .idji'-iing the air intake s lull' a a long tubular exten of the larger particles doepiacticable. The intake i lilted with a smoothing dev angle bend in order to stop the air intake speed wet particles greater than 10 m, nation would be a fair men Whilst the cut-off of particle in size should be reasonabl of those just below this size in the sample. The proi ittpidly as the motion of tin dependent on the moveme: the low size-frequency rain a micro balance sensitive essential. Taisi i I REE FALLING SPh PARTICLES Particle diameter (in microns) 1000 750 500 300 100 50 2-5 As an alternative to this scope can give a good estim ol particles below 6 microns frequency curve is not reqt inclusion or exclusion of I; sample is immaterial. Ha factory average sample by iltcr and hand syringe, the o from the dust by means of i dust may then be agitated alcohol. After agitation a suspension is quickly removi pipette and transferred to a scope slide. When the slick able deposit of sufficient ck may be made at random p means of the 4-mm. objectiv> K'aticule in the cye-piece. above 6 microns in size, average count within the rec sniiple calculation will give n the slide and so the total SUsP' 'Wion. Much of the ' s'uk Lom a suspension is veni,, :\ e sample of the large i ' much less I he ii;^, | n that of the fettler. I >n of the dusts shov. ,|,ilt i' the particles a,, |CSs ctual weight 01 ||1K i per cent, of the total the dust which may ^ tie is above the resolving and below- 6 microns in ;s concentrations without provide a true measure of cial precautions are taken ess of the upper size lumt ted by a comparison of ig. 4 and 4a). Including I gave a slightly higher ile No. 7. The particle that the hazard for the articles per c.c.) w'as more le medium fettler (No. I, he airborne dust from the arser than that produced This may be due to the tough it seems likely that / partly responsible. The vorking on the inside of ance there was a definite s the shop. Large parocess at high velocity are iir currents whereas small ` carried away from the e is made for the higher r breathed by the large ard. of this worker is fifty t general body of the | g presents a nine times amatic mould filling and five times. Owing to the ially spent by the worker ust hazard will be much Dove. Large particles of n the air of the main body : samples from pneumatic (Nos. 3 and 4). This last .ich were partly coked, and : fumes breathed by the ; of tar cannot be ignored, i all fettling shop consisted lundum particles, and the appear to be excessive, he core shop are handling icir time, the nature of the ul binding is such that air rcc is very low indeed , samples from the main I is. 9, 10. 11 and 12) show pollution in the foundry :rnal standards, of atmospheric pollution j in the foundry, measureins represents the simplest 1 on changing conditions. i i LA L i i i A / v ij L, v *. * 11, i * i il. is. * Li i i i iy / \ <j till. pjg. 4 and 4a show very clearly that if the large particles could be excluded, then the mass concen tration would also enable the dust hazard to be measured accurately. This presents some difficulty f0r samples which are made up partly of highvelocity particles. The terminal velocities of quartz particles falling in still air are given in Table 5. By adjusting the air intake speed to the filter, and fitting a long tubular extension to it, the exclusion of the larger particles does not appear to be im practicable. The intake tube would need to be fitted with a smoothing device and to have a rightangle bend in order to stop high-speed particles. If the air intake speed were adjusted to exclude particles greater than 10 microns, then the concen tration would be a fair measure of the dust hazard. Whilst the cut-olf of particles larger than 10 microns in size should be reasonably sharp, only a fraction of those just below this size limit would be included in the sample. The proportion would increase rapidly as the motion of the particles became more dependent on the movement of the air current in the low size-frequency ranges. With this method a micro balance sensitive to 001 mg. would be essential. Table 5 are numerically insignificant, and of little interest from the point of view' of the health of the worker, the sampling difficulties and the necessity to under take a great many size comparisons would largely disappear with this technique. The actual count and calculation would not take more than an hour and since the moist chamber will hold a relatively large volume of liquid (0-3 c.c.) the error from this is much less than that incurred by using the standard hacmocytomcter cell. After filling the cell, the chamber should be allowed to stand at room temperature when an even deposit of the dust in suspension will be deposited on the slide. Hi al t it Studies Although some indication of diseases to which the foundry worker is subject can be obtained from a study of the Occupational Mortality figures of the Registrar-General's Decennial Supplement (1931) the figures are apt to be misleading for a variety of reasons. It has therefore been found advisable to restrict this part of the investigation to known facts within our own experience, namely, the incidence of sickness and accidents among foundry workers compared with a similar number of workers in another department. FREE EALLING SPEED OF QUARTZ PARTICLES IN AIR Particle diameter (in microns) 1000 750 500 300 100 50 2-5 Approximate terminal velocity (cm. per sec.) 410 300 12-5 4-5 0-5 01 003 As an alternative to this procedure, the micro scope can give a good estimate of the total number of particles below 6 microns in size, providing a sizefrequency curve is not required. In this case the inclusion or exclusion of large particles from the sample is immaterial. Having obtained a satis factory average sample by means of the crystal filter and hand syringe, the crystals may be separated from the dust by means of a hand centrifuge. The dust may then be agitated in a definite volume of alcohol. After agitation a suitable quantity of the suspension is quickly removed by means of a micro pipette and transferred to a moist chamber micro scope slide. When the slide has dried and a suit able deposit of sufficient density obtained, counts may be made at random parts of the deposit by means of the 4-mm. objective only, with a Patterson graticule in the eye-piece, ignoring the particles above 6 microns in size. Having established an average count within the rectangle of the graticule, simple calculation will give the total particle count on the slide and so the total particles in the original suspension. Much of the trouble in preparing a slide from a suspension is in obtaining a repre sentative sample of the large particles. Since these Sickness and Accidents The reaction of the foundry man to his environ ment has been attempted by comparing the nature of the absence due to sickness and accidents occur ring in the Foundries with that taking place in the Constructional Department at Butterley during the past twelve months. The Constructional Depart ment has been selected for comparison not only because there is not an undue disparity between the numbers employed in it and the foundry respec tively, but also because the Registrar-General's Decennial Supplement (1931) showed no significant rise in mortality among constructional engineers due to conditions other than accident, unless a possible significant excess of cancer deaths is taken into account. The results of these studies are shown in Fig. 5 and Table 6, and it will be seen that contrary to what might have been expected, the number of cases of respiratory disease occurring in the Foundries was lower than in the Constructional Department, although the average number of days lost per case was higher. Affections of the skin showed a greater incidence though rheumatic cases were in about the same proportion, but accidents were fewer and less time was lost from this cause, despite the fact that two cases of herniotomy are included in the accident figures. Respiratory Disease The fact that the average number of days lost per case due to respiratory disease is more in the Foundries than in the Constructional Department suggested that the nature of the respiratory con ditions might be of a more serious nature among 132 BRITISH JOURNAL OF INDUSTRIAL MEDICINE Table 6 CASES OF SICKNESS AND ACCIDENT ABSENCE IN THE FOUNDRIES AND CONSTRUC TIONAL DEPARTMENT AT BUTTERLEY Foundry Constructional Nature of condition Number of cases per 100 persons em ployed Average number of days lost per 100 per sons em ployed Number of cases per 100 persons em ployed Average number of days lost per 100 per sons em ployed Respiratory dis ease . - 26-9 492 39-7 417 Skin .. .. 90 130 3-2 94 Rheumatic disease 80 108 8-1 117 Psychoneurosis 1 -9 59 2-5 29 Gastro-intestinal 80 79 90 172 Genito-urinary.. 0-9 21 0-4 2 Circulatory .. 20 36 3-9 59 Miscellaneous .. 178 77 60 71 Operations .. -- -- 1 -3 19 Infectious dis eases .. .. 21 20 Accidents . . 14 6 217 15 2 345 Foundries (219 workers). Constructional (282 workers). workers in the foundries, due possibly to the dusty atmosphere, so an investigation was carried out to determine the extent to which dust had affected the lungs. Sixty men working in the Foundries were examined and a full history, including a complete occupational history was taken from each person; this was followed by a physical examination in cluding chest radiography, and the results of this investigation are shown in Table 7. Table 8 gives in summary form the results of the x-ray survey in the different age groups of those examined, while in Table 9 is given the length of time to which those examined were exposed to a dust risk. No cases o , tuberculosis or silicosis were noted. Butterley is in a coal-mining district and the investigation was complicated by the fact that the occupational history of a number of those examined included coal mining, itself a dusty occupation., Neither of the fettlers showing lung changes, how ever, had been at any time engaged in colliery work/' although two out of the eight moulders had been coal miners and two out of the three noted amongst the other occupations. This investigation indicates, therefore, that 21 peri cent, of all the foundry workers examined showed some evidence of dust changes in the lungs, but 40 per cent, of fettlers were affected in comparison with 25 per cent, of moulders and 12 per cent, of other workers: moreover the degree of dustiness in the fettlers' lungs was much heavier than in the case of other workers in the foundry. In general the degree of dustiness of the lung depends on the length of exposure to the dusty' environment and, although there is some idiosyn-' crasy, exposure of many years duration is usually, necessary before any marked changes occur. Thus,: in the case of the fettlers, those showing evidence of dust in the lungs had been exposed to risk for over twenty years. Although the total number of those examined is small, the results are largely in accordance with the findings in other and more extensive surveys of a similar nature (Sander, 1938; McConnell & Fehnel, 1934) indicating that there is a greater risk of the' occurrence of dust changes in the fettler than in other workers in the foundry. That dust changes should occur more commonly in the lungs of the fettler is not surprising in view of the mass concen-; tration of the dust, the size of particles, and the Foundry JAN Constructional Department Sickness Absence Widunl Absence Flu. .'.--Sickness and accident absence in the foundry during 12 months, compared with Constructional Dept- -- (The number of days lost is calculated for each hundred persons employed.) ICINE length of time to which. th0y, I to a dust risk. No c.: ,<js ' "' noted. c. ning district anu the ilicated by the fact that iht a number of those examined itself a dusty occupation showing lung changes, howme engaged in colliery work, he eight moulders had been t of the three noted amongst licates, therefore, that 21 per workers examined showed changes in the lungs, but were affected in comparison oulders and 12 per cent, of er the degree of dustiness in much heavier than in the i the foundry. e of dustiness of the lung of exposure to the dusty ugh there is some idiosynly years duration is usually irked changes occur. Thus, ;rs, those showing evidence d been exposed to risk for imber of those examined is gely in accordance with the tore extensive surveys of a 938; McConnell & Fehnel, c - -:s a greater risk of the i n the fettler than in uuovy. That dust changes imonly in the lungs of the , n view of the mass conccn size of particles, and the lal Department Fig. 6 (above).--View of a well laid out semi-production foundry. Note high the effect of good general lighting. standard of general cleanliness and Fig. 7 (below). -Sand-preparing plant. Modern methods of mechanization prevent dusty atmosphere. wnh ConslriiLlion.il Dcpl np1 " ed.) Fig. 8 (above).--Moulding machines and conveyor system for moulds. Hg. lO(above).--The ` knock- on the left separate the mo sand on the casting is thei with a hammer. The semi- then conveyed to the fettlin II fritThn --Tappirv* the ..ki; ls then in turn poured into ulds. Fig. 10 (above).--The ` knock-out '. The men on the left separate the mould boxes: the sand on the casting is then knocked out with a hammer. The semi-clean casting is then conveyed to the fettling shop. Fig. 11 (right).--Tapping the cupola. The molten metal (at 1400 C.) in the ladle is then in turn poured into the mould. Fig. 12 (above) High-speed swing-frame grinder using bakelite bonded wheel. Note absence of local exhaust system. Fig. 13 (below).-- Hydro-blast in action. The operator wears full protective clothing including helmet to which ' clean air is sunnlied. The stream of water and sand has a velocity of 3 miles per minute. HEALTH AND EA OCCUPATIONAL Hh No. of ( ,oc \ : years Age engaged in r Foundry work 4v. 46 4(6 24 414 24 21 9 41 ; Cl: 550 54 5 1 p,, 555 48 518 47 u 24 12 1 Ac S 401 ' 23 479 30 8 j Pu 4 1 In' 428 24 6 ; pu 410 24 10 380 21 431 26 4()( 42 36i 18 3X5 20 373 23 494 23 368 17 6 ' Em 12 Fin XX 1 i So s Pip. I1 5 ' Sum 7 ' Dm 8 1 R\ 415 43 537 65 21 , Cl>T ! 3 Co! 558 5s 534 40 40 11 10 ' Col Lie 8 Ko, a I' .7 12 Col 5) 40 44 *> '12 40 ' 1 ' 47 7 a 7 62 s A 10 591 65 476 38 30 3 459 .'3.X s 7 44 i Col I N: 1 'I : Col* I; \ c. ' Col [t \c |>OU ' lie ; 'iii . Col! Ski: no CO: Sin i Ii i cthoii used for classifies Normal lung, Class i in | > markings). Class III. I la I I. third stage silicosis. bsence of local exhaust luding helmet to which v per minute. liL.^i-tii A hi) t. h v Ik()\\l hi\ 1 'A L ( ()i\l)i I i()\.'> ih ini. iHOh /t/cvi/n i Taiii.i. 7 OCCUPATIONAL HISTORY AND LUNG CHANGLS AMONG 60 LOUNDRY WORKI RS t . I No. of years Age engaged in Foundry work Previous employment in other industry Principal occu pation while employed in Foundrv Present occupa tion and how long X-ray Class * 486 ; 46 403 1 24 419 ; 24 556 401 i 23 479 30 380 433 385 i 20 373 : 23 494 I 23 368 j 17 558 : 55 534 I 40 525 40 550 ! 58 548 40 532 i 40 593 65 476 38 21 Nil. Fettling. Fettling 21 vears. Ill 9 Nil. M oulduvj. Core shoo 5 y ears 1 41 Cutting silk from bobbins. Moulding. | Moulding II i 4', vears. Pottery: on day modelling u'heel 13 Sand drier. Sand drier II years: H.M. Forces 2 years; collier; : 5 \ ears. weighing coal 20 sears. 24 Nil. Moulding. Core Shop. II 12 Acetylene burning. Constructional Lug. Cupola Works. Cupola Works II Shop; colliery roads 2 years; coal 12 >cars. getting 6 years. 8 Pit Bank I yea r. Moulding Moulding 8 vears. II 4 i Iron rolling mills II years; Celanese Moulding. Moulding. III 2J years. 6 , Pit 10 weeks. Mcchani/ed Sand Mechanised Sand III Plant. Plant 6 years. 10 Nil. Moulding. Moulding II 10 years. 6 Errand boy I year. Moulding. Moulding 6 vears. II 12 Foundry crane driver 6 months. Moulding. Moulding 12 years. II IT Stringing bobbins 6 months. Moulding. Moulding III 22', years. Pipe making: pneumatic hammer driver Moulding. Moulding 1 year. II 1 year: pit bank 1 year. 5 Sand mixer 1 year; shop I year. Moulding. Moulding 4 years. II 4- 7 Dismantling cases. Moulding. Moulding 7 vears. III 8 Nil. Fettling. Fettling 8 vears. 11 1 ; Rivet carrier . General General labourer 1 labouring. 1 year. 21 Colliery loader 3 years: textile factory Moulding. Moulding III 2 years: labourer 2 years. 19 years. 3 Colliery: ganging 6 years; loading 10 La bourc r. Labourer 3 years. 1 years. Contractor 30 years. Navy 4 years. 10 Colliery: ganging 4 years; loading then Labourer. Sand Mixer. II i getting coal for 27 years. 8 Roadman 3 years: iron rolling mills, Htter. Filter 8 years. II apprentice fitter in Canadian foundry 7 years. 12 Colliery surface work 14 years. La hourcr. General labourer, II night work, 12 vears. 44 Nil. Lverv job in turn. Casting. II Colliery: coal face gelling coal 23 years. Labourer. Night labourer III Night porter 5 years. A.R.P. Warden 2 years. 1 2 years. 1 Colliery: surface work I year; roads Cupola charger. Copula charger II 13years. Bricklayer's labourer 5 7 years. years. Foundry labourer 1 year. C" olliery: surface work I year. H.M. Cupola. Cupola. II 1 orces 4 vears. Blast furnace 28 years. 10 Pottery : mtiking bottles I year. Col- Cupola hank. Sweeping up. II her; : pony driver 30 years. Con structional eng., carrying iron. 30 Colliery: liring boilers Moulding. Moulding 30 years. II 3 Sharpening pencils 1 year. Confec tioner 8 years. Labourer on camp Grinding. Grinding. II construction I vear. ' Nil. C ore shop. Cores 6 years. II Surveyor's depot 13 years. H.M Labouro r. Night labourer II I-orces4 vears. Colliers surface 22 vears. 3 years. 477 44 Labourer I vear. Collierv : coal fuse Moulding. 25 vears. Moulding 4 years. II * I lie meilaul imcd I'm elassilication ol the radiological appearances has been: f/ao / Normal lung ( A/o //. Increased markings hut not beyond noim.il limits lor . i lown cl vs el ler I indicates excess i\ e ma; k i ngs). ( dn /// I a rly ret icu lat ion ( An > / I `. Fi rsi si a ge silicosis. ( hr v \ I . - Second stage si I icosis CIum b1. Third stage silicosis. 138 BRITISH JOURNAL OF INDUSTRIAL MEDICINE Table 7.--continued No. of Case No. Age years engaged in Foundry Previous employment in other industry work Principal occu pation while employed in Foundry Present occupa tion and how long X-ray Class* 641 64 611 27 544 46 526 57 487 36 609 20 562 60 556 60 497 34 489 24 406 24 385 21 367 41 591 62 595 54 594 51 615 15 614 38 619 34 623 29 633 33 612 26 632 58 629 46 626 68 628 53 33 10 5 25 21 6 40 6 13 94 10 5 20 47 41 40 11 months 23i 20 15 16 10 42 23 53 39 Colliery: coal face 6 years. H.M. Army 4 years. Foundry: pipe making 2 years. Colliery: blacksmith 2 years. Timber ing, dattling 18 years. Colliery black smith 2 years. Foundry blacksmith 2 years. Air Ministry 6 months. Stable boy and butler valet 10 years. Great War 6 years. Boilers 12 years. Foundry fitter 6 years. Celanese: bob bin winding 1 year. Nil. Moulding. Cores. Fettling. Stripper. Fettling. Moulding. Stone breaker 1 year. Moulder. Farm labourer and colliery loader 5 Labourer. years. Labourer, furnace man. Bricklayer 5 years. Cupola repairs. Foundry 1| years. Hosiery mill. Stripping bobbins 6 months. Fettling. Moulding. Foundry: sand mixer 1 year. Cotton mill: cleaner 3 years. Colliery: ganging 2 years; stall 3 years. Foundry labourer 2 years. All jobs in iron foundry. Moulding. Moulding. Loam moulding. Sand mixing and core making. Casting various. Sand moulding 3j years. Loam moulding. Nil. Iron foundry: pattern shop 2\ years; core making and moulding 6j years. Farm labourer 1 year. Nil. Labourer 1 year. Pipe foundry 2^ years. Core making 6 months. Core making. Moulding. Nil. General labouring. Turning shop slinger in foundry 9 months. Railway porter 9 years. Core making 2 years. Ships' stoker in i summer, lumberjack in winter (6 years j in Canada). ! Colliery dattling 1 year. Nil. Core making. Moulding. Moulding. Moulding. Moulding. Moulding Cores 10 years. Fettler 3 years. 11 II 11 Stripper 13 years. 11 Fettling and grind ing 21 years. Moulding and slingers 6 years. Labourer 6 years. Labourer 6 years. III I in in Cupola repairs 7 years. Fettling 8 years. Moulding 10 years. Moulding 4 years. Moulding 18 years. ii it n+ n+ III Loam moulding 30 years. Loam moulding 20 years. Loam moulding 8 years. Loam moulding 5 months. Core making 17 years Moulding 20 years. Moulder 15 years. Odd jobs, but mostly mould ing 13 j- years. Core making 10 vears. Moulding42 years Moulding. III II 11 + I I II II III II II HI Moulding 53 years II Moulding 39 years 11 * The method used for classification of the radiological appearances has been: Class I.--Normal lung. Class II.--Increased markings but not beyond normal limits for a town dweller ( indicates cvcessive markings). Class' III.--Early reticulation. Class 1C.--First stage silicosis. Class' V.--Second stage silicosis. C lass t'/.--Third stage silicosis. nature of the dust to which he is exposed. The failtire of the majority of foundry workers to show dust changes in the lungs may be attributed to the relatively small amount of free silica suspended in the air which they breathe, as well as to the presence of an appreciable jvercentage of alumina. The work of Denny. Robson and Irwin (1937 and 1939) has shown that powdered aluminium in very small percentage has a marked elfect in preventing the development ol silicosis following exposure to quart/ dust, and Leroy Gardner (1944) has demon strated beyond doubt that aluminium hydrate specifically inhibits fibrous reaction to quartz. Before leaving the subject of respiratory disease reference should be made to the increased incidence of carcinoma of the lung already noted in the foundry worker; but it must be remembered that it is also found in those who work metal cold. Perhaps the higher number of cases occurring in foundry workers is due to a possible carcinogenic action of the fumes which sometimes occur in the foundry. It may be of interest to note that Argyle Campbell (1943) showed that mice exposed to a moderate cloud of iron oxide developed a significant rise in the occurrence of lung tumours compared with controls. HEALTH AND E> Tabu X-RAY SURVEY OF WOR l-OUNI fotal number examined -- 60. P.nt One. Showing number exm Age under 20 21-30 3 1 -4< KuIjx X .. - 21 Mouldeis .. 2 X 12 4 Olliers . , . [Dial number examined . . [oral number showing dust changes in age gtoups .. 1 3 -- 47 IS 12 33 Tabu X-RAY SURVEY OF WOR! FOUND Total number examined--60. Part Two. Showing lengr Lcntu Ii of posure. ex under 2 yrs. 3-5 6-10 Fculers Moulders .. - 1 X .. ! X 6 6 Oiherx .. .. X I XX 59 lotal number showing dust changes ac cording to length of ex- poxure to dust 1 1 3 Lual number examined . . 2 12 17 Skin Affections Most of the skin cases w usually the result of mild si and the only inference vvhn them is that probably the f through a break in the conn easily and carries the comnn Although no cases occur! review there is nevertheless tional dermatitis in foundry shows itself in the form of ln many other industries. Ii '`"s occurs most commonly ln whom the irritation appe: l|sed in the core sand, but huindry are not immune ai sand alone. Another type sionally seen similar to that nilne' and affecting the a' Cl 1P-Mtos a worker showing du" .uii. VFAJTH 4 V) FNVfROV*.* fwt * i rv tnf rr>n\' ^/'.vnnv 70 :/NE Table 8 other parts of the body where much friction and X-RAY SURVEY OF WORKERS AT BUTTERLEY FOUNDRY sweating take place. This is in effect an intertrigo. resent occupa tion and how long Total number examined -- 60. Average age 29 years. part One. Showing number examined in different age groups.* Rheumatic Disease Until the causes of rheumatism are more definitely established it is not possible to give exact reasons for the high incidence of rheumatic disease in Moulding foundrymen; all that can be said is that the disease is very prevalent amongst workers exposed to Cores 10 years. Fettler 3 years. sudden changes of temperature and strains on the muscles from heavy occupations. Exposure to heat does not cause as much trouble as might be expected. Heat cramps are uncommon Stripper 13 years. Fettling and grind ing 21 years. Moulding and . slingers 6 years. Labourer 6 years. Labourer 6 years. but not unknown; vague muscular pains may be due to salt depletion but Fantus- test for chlorides (War Office, 1943) in the urine gives an easy means of determining whether a fall below the dangerous excretion level of 3 g. in the twenty-four hours has taken place. Cupola repairs 7 years. Fettling 8 years. Moulding 10 years. Moulding 4 years. Moulding 18 years. II II IF. 114IH Table 9 X-RAY SURVEY OF WORKERS AT BUTTERLEY FOUNDRY Total number examined = 60. Average age = 29 years. Part Two. Showing length of exposure to dust.* Accidents It has already been seen that the Foundries had fewer accidents and much less lost time due to this cause than the Constructional Department. The accidents in the Foundries were not on the whole of a serious nature and surprisingly few burns caused trouble. Indeed, burns are much less Loam moulding 30 years. Loam moulding 20 years. Loam moulding 8 years. Loam moulding 3 months, re making 7 years Moulding 20 years. Moulder 15 years. Odd jobs, but mostly mould ing 13^ years. Core making 10 years. Moulding42 years. Moulding. Ill II III 1 II II III II III Length of posure. ex under 2 yrs. 3-5 6-10 11-15 15-20 21-25 26-30 over 30 Fettlers .. - 1-- -- -- x2x - -- Moulders X .. 1 X 6 X X X XX XX 62 34 1 10 Others .. .. X 1 XX 59 4-- 3-- -- Total number showing dust changes ac cording to length of ex posure to dust 1 1 31 14 2 Total number examined .. 2 12 17 6 39 1 10 Skin Affections Most of the skin cases were of the septic type, common in foundry practice than might have been anticipated. Preventive Measures Pre-employment Examination In view of the relatively high risk of disease occurring in the foundryman, a complete physical examination, including x-ray of the chest, should be carried out on all those entering the industry (Lancet, 1938, 2, 629). A history of respiratory disease is important, and taken in conjunction with x-ray findings may be enough to exclude an applicant from foundry work. Even in the absence of an anomalous x-ray one would hesitate to allow a person with a history of recurrent bronchitis to work in the foundry. X-ray Moulding 53 years. 11 Moulding 39 years. II usually the result of mild staphylococcal infection, and the only inference which may be drawn from them is that probably the fine dust makes its way through a break in the continuity of the skin rather evidence of tuberculosis, either active or quiescent, or of fibrosis of the lungs, is an absolute bar to foundry work. Those with infected tonsils or rhinitis, either hypertrophic or atrophic, do not as r a town dweller (-f indicates is V.--Second stage silicosis. easily and carries the common bacteria with it. Although no cases occurred in the period under review there is nevertheless a real risk of occupa a rule do well in foundry work as they are liable to exacerbations of tonsillitis or rhinitis, often asso ciated vvith sinusitis. They are better out of the tional dermatitis in foundry work. This generally foundry, but it is permissible to give them a trial. 'ject of respiratory disease shows itself in the form of the skin irritation seen Workers with perforated car drums should be : to the increased incidence in many other industries. In our experience derma rejected, both on account of the risk of exacerbation ing already noted in the titis occurs most commonly amongst core makers of otitis media and also because they do not stand must be remembered that in whom the irritation appears to be due to the oil up well to the noisy conditions of machine moulding. >e who work metal cold, used in the core sand, but other workers in the People with previous history of skin disease or with ber of cases occurring in foundry are not immune and may be affected by actual dermatitis should be excluded, as also should to a possible carcinogenic sand alone. Another type of dermatitis is occa those with very dry skins or those who tend to ;h sometimes occur in the sionally seen similar to that occurring in the coal sweat unduly. merest to note that Argvle ( miner and affecting the axillae and groins and* The value of the pre-employment examination I that mice exposed to a side developed a significant * x indicates a worker showing dusi changes in the lung on x-ray examination. cannot be rated too highly; it is ot far more import ance than any subsequent examination, lor il it is f lung tumours compared 140 BRITISH JOURNAL OF INDUSTRIAL MEDICINE carried out conscientiously the greater number of those who are likely to break down under foundry conditions can be excluded. This is not to say that periodic examinations are not required, for it is agreed that they are desirable under any circum stances. Time does not allow of the periodic examination of employees in a large organization as frequently as one would wish, but we are aiming at a quarterly check on young persons up to 18 years of age with annual x-ray, and an examination, including x-ray, at five-year intervals for the older workers. Admittedly this is not ideal, but it should be sufficient to serve as a check on the dust hazard. Building a New Foundry Modern methods of construction and ventilation can greatly improve the conditions of the foundry. Noise and vibration can be reduced enormously, and a less vitiated atmosphere obtained. Proper cloak-room and washing facilities, including bathing facilities, are important and should receive as high a priority in consideration as the production part of the foundry. The Existing Foundry In the already existing foundry, as in other shops, the attention of the management should be directed to defects in lighting and ventilation; but heating, floors, and house-keeping are most difficult prob lems. In winter weather the shop is liable to be cold in the morning before casting begins and it is difficult to see how this can be overcome without an air conditioning system. Concrete floors are desirable as they are com paratively easy to keep clean, but they are satis factory only in the case of the mechanized unit where pouring takes place at a definite point and there is no great risk of spilling metal on to the floor with fragmentation of the concrete. It is quite otherwise, however, in the foundry dealing with large castings or where pouring is done with the boxes on the floor, although concrete walk-ways may be possible. Good house-keeping is easier where there is a concrete floor but is by no means so easy in the foundry as in some other shops. Baths It has been shown that rheumatism lakes a high place amongst the hazards of the foundry, and Osgood (Ih32l after emphasizing the importance of proper environmental conditions both at work and away from it in the prevention of this disease, stresses the necessity for providing shower baths at work. The provision of baths is no less necessary in order to reduce the high incidence of skin con ditions. and there is no doubt that changing rooms and shower baths qji the principle of pit-head baths are urgently needed in the foundry industry. Baths are not sullieieni in themselves and frequent change and washing of working clothes are required in order to contiol skin conditions. Bathing facilities will not only improve the health of the worker in the foundry in an overt manner, but also indirectly by enabling him to pass to and from his work as clean as any of his companions in less dirty trades and by so doing increase his self respect. Drinking water should be provided at suitable points and is best supplied by bubbler fountains. Salt tablets should be available if neces sary for those exposed to excessive heat so that the risk of heat cramps may be minimized. Protective Equipment Hand leathers should be supplied to those handling rough castings, and all foundry workers should wear properly protected boots. Leather spats or spat leathers with strap fastenings should also be used to protect against splashes of molten metal. Aprons should be of asbestos .or of material rendered fireproof by chemical means. A proper eye-protective appliance must, of course, be provided for those exposed to the glare of furnaces and molten metal, and grinders require goggles to prevent injury to the eyes from flying particles of metal and dust. Respirators are also needed for grinders, and they should also be worn by those engaged on dusty processes which cannot be kept properly under control such as the repair of cupola linings. Dust The main specific health risk of the iron foundry is the inhalation of free silica, and the substitution of an innocuous material for a harmful one is the best way in which to deal with any hazard. The use of olivine which is a mineral composed of magnesium and ferrous orthosilicate (MgFe,SiOt) and which recent work (King and Rogers, 1945) has shown to have no fibrosis-forming effect on the lungs, has been suggested (Goldschmidt, 1938) as a practicable substitute for the sand used for the body of the moulds. Whether this substance proves to be technically satisfactory remains to be seen, but there is no possible justification for the use of a silica parting powder when equally effective non-siliceous powders are available; and this is largely true also of silica paint. As long as a sand containing free silica is in use in the foundry, dust control will remain vital, the principal danger points being the knock-out, stripping, fettling and grinding operations, including rumbling and blasting by means of wheelabrator, sand-blasting or other methods. The regulations regarding sand-blasting render the process reasonably safe and the enclosed types of wheelabrator or rumbler with exhaust extraction are also satisfactory, provided that the extraction system works efficiently. Grinding carried out in accordance with the regulations also meets the case, but the knock-out and fettling operations are not governed by regulations and require special con sideration. In the case of the knock-out the cliHiculty can be largely overcome by drawing the dust downwards through the grating by artificial means 1 HEALTH AND ENl isee tig. 10) while the fettling i he done in a similar mannei constructed on the grating p I ,m exhaust system. The larger casting presv although a pneumatic chisel I and flexible duct has been i ic-ailiv Tests made in the U Niiggcst that there is no risk < the operation of hydro-blasm this country where the plant i certainly seemed very clear, carrying out this kind of woi piotective clothing (see tig. I Although the greater amou the atmosphere of the ntech. kept under control by suitah ventilation, installation of t: of cleaning castings should I in all large foundries. Increu has the merit that it reduces lifting, for in far too many foi , in excess of the generally a lifted all day and every day. Acknowledgi Our thanks are due to Mi of the foundries of the Bun for much help in the desen processes; to Mr. John Gai reproduced in figs. I and 2; a Limited, for the photograph; methods. We must also Secretary of the Medical Lk valuable assistance througho; (his paper. Summar A brief description is given . methods. Environmental studies were foundries employing over 200 included a survey of ventilatio oust hazard. Id assess the dust hazard in required of (a) the dust concent; 'Pheie. (A) the duration of wort composition of inhaled dust, frequency. In this survey it is shown tha urge castings have the dust foundry. Chemical analysis si' "insists largely of silica part; under consideration it is estimai " 'he lettler of large eastings "Orker in the general body ot I .mndry in an oven m-inn nabling him to pass i as any of his compai ns lr| v '---doing increase In x.|, - ould be provided lM ncjf supplied by buhh|0 should be available if neccv to excessive heat so that ihc be minimized. Id be supplied to those s. and all foundry workers protected boots. Leather ith strap fastenings should against splashes of molten sc of asbestos .or of material critical means, e appliance must, of course, exposed to the glare of tetal, and grinders require y to the eyes from Hying Just. Respirators are also I they should also be worn sty processes which cannot control such as the repair th risk of the iron foundry silica, and the substitution I for a harmful one is the :al with any hazard. The . " mineral composed of silicate (MgFe.SiO,! king and Rogers, 1945) has osis-fornting effect on the I (Goldschmidt, 1938) as a >r the sand used for the Whether this substance satisfactory remains to he 'ssible justification for the vder when equally effective re available; and this is paint. As long as a sand n use in the foundry, dust the principal danger points >ping, fettling and grinding imbling and blasting h> sand-blasting or othei ling sand-blasting rendei fe and the enclosed types er with exhaust extraction oided that the extraefon Grinding carried out in ations also meets the tw. .'tiling operations are not and require special conif the knock-out the ditliome by drawing the dust irating by artificial mean> nnL> Li\ k iROA fviFNi'AL cO/V>j/ JONS ii\ ltit. JHOiv FOUNDR Y i4i (see fig- I) while the fettling of small castings can tg done in a similar manner on a mild steel bench instructed on the grating principle and fitted with an exhaust system. The larger casting presents special difficulties although a pneumatic chisel fitted with a small hood and flexible duct has been tried with encouraging results. Tests made in the United States of America sUggest that there is no risk of inhalation of dust in the operation of hydro-blasting, and in a foundry in [his country where the plant is in use the atmosphere certainly seemed very clear. Meanwhile the fettler carrying out this kind of work should wear suitable protective clothing (see tig. 13). Although the greater amount of dust and fume in the atmosphere of the mechanized foundry can be kept under control by suitable methods of exhaust ventilation, installation of the hydro-blast system of cleaning castings should be carefully considered in all large foundries. Increased mechanization also has the merit that it reduces the amount of weight lifting, for in far too many foundries weights greatly in excess of the generally accepted standards are lifted all day and every day. Acknowledgments Our thanks are due to Mr. G. Walker, manager of the foundries of the Butterley Company, Ltd., for much help in the description of the technical processes; to Mr. John Gardom for the drawings reproduced in figs. I and 2; and to Messrs. Pneulec, Limited, for the photographs illustrating foundry methods. We must also thank Miss Pullon, Secretary of the Medical Department, for her in valuable assistance throughout the preparation of this paper. Summary A brief description is given of modern ironfounding methods. Environmental studies were carried out in two foundries employing over 200 workers. These studies included a survey of ventilation and heating, and the dust hazard. To assess the dust hazard in a foundry knowledge is required of (a) the dust concentration in the work atmo sphere, (b) the duration of work spells, (c) the chemical composition of inhaled dust, and (d) its particle-size frequency. In this survey it is shown that fettlers of medium and large castings have the dustiest occupation in the foundry. Chemical analysis shows that the dust here consists largely of silica particles. In the foundries under consideration it is estimated that the silica hazard of the fettler of large castings is lifty times that of a worker in the general body of the foundry; medium fettling represents a nine times greater hazard; and pneumatic mould-filling and shaking-out no more than five times. Workers in the core shop are exposed to a minimal dust hazard because of the nature of the material used. Routine control of atmospheric pollution in a foundry is essential. The simplest way of doing this is by mass concentration estimations of airborne dust at breathing height. Sickness and accident rates among the foundry workers were compared with those in another depart ment (constructional). The number of cases of respiratory disease in the foundries was less, although the average number of days lost per case was higher. Sixty foundrymen had chest x-ray examination. While 21 per cent, of these showed some evidence of ` dust change ' in the lung (40 per cent, of fettlers being affected), no case of silicosis was found, even in its early stages. Affections of the skin were greater in the 200 foundry than in the constructional department, most of them being mild staphylococcal infections. Dermatitis in the foundry occurs most commonly among core-makers. The incidence of rheumatic disease was greater among the foundrymen than among the workers in the con structional department. No definite reasons can be given for this. Among foundrymen heat cramps are uncommon but not unknown. Accidents causing injury were fewer and caused much less lost time in the foundries. Burns are less common in foundry practice than was anticipated. Preventive measures against accident and ill-health are (a) pre-employment medical examination, including chest x-ray; (b) improvement of ventilation by modern construction methods; (<) proper cloak-room, washing and bathing facilities; (d) attention to floors; (e) by adequate protective equipment for the individual worker; and (/) prevention of fumes and dust by alteration in materials where possible, by increasing mechanized methods of production, e.g. introducing the hydro-blast system, and by good general house-keeping. References Campbell, J, A. (1943). Brit, tried. J., 1, 179. Denny, J., Robson, W., and Irwin, D. (1937). Canad. tried. Ass. J., 37, I. Gardner, L, U., Morris, D., and Delahant, A. B. (1944), J. industr. Hyg., 26, 7. Goldschmidt, V. M. (1938). Industr. Eng. Cftem., 30, 27. Industrial Environment and Health. Internat. Lab. OIL, Geneva (1936), 124. Instil, of Mining and Metallurgy. Papers on Dust Sampling Investi gations. London, 1938, 145. King, E, J., and Rogers, N. (1945). Proc. ray. Soc. Med. (in the press). Lowrie Fairs, G. (1944) Client. Ind., 62, 374. McConnel, W. J., and Fennel, J. W. (1934). J. industr. Hyg., 16, 227, Monmouthshire and S.W. Coal Owners Ass. 7th Rep. Coal Dust Res. Com. (1942). Experience gained in sampling. Osgood, R. B. (19 32). New Engl. J. Med., 206, !. Registrar-General's DecenniaI Supplement, England and Wales, 1931. Part 11a: Occupational Mortality (1938). H.M.S.O., Lond. Report of the Committee appointed to consider the Problem of Dust in Steel Foundries (1944). FI.M.S.O., Lond. Ross, A. A,, and Shaw, N. FI. (1943). Dust Hazards in Australian Foundries. Tech. Rep. No. t. Dept. Labour and National Service. Commonwealth of Australia. Sander, O. A. (1938). Airier. J. puhl. Hlth.. 28, 601. Stln osis in Foundry Workers (1938). Leading Article, Lumet, 2, 629. War Office: Army Med. Depi. Bulletin No. 23 (1943). A Feu lor Salt Depletion. L