Document jywavm63YdNrRm3kz3nQvzy1R

C,(r\ lO'oSWWS'S SOUTIIHRN RHODKSIA REPORT of the Commission appointed to enquire into the possible prevalence and origin of cases of Silicosis and other industrial Pncumonoconioses in the industries of the Colony of Southern Rhodesia, and of Pulmonary Tuberculosis in such industries. presenteb to tbc Xcololntive loss. Printed for the Government Stationery Ofllrc by th RWlcrian Printing and Publishing Co., Ltd., Salisbury. <"SR. U8 1938.J 1938 i a.m! it *Kt--ni:o SOUTHERN RHODESIA. REPORT of the Commission appointed to enquire into the possible prevalence and origin of cases of Silicosis and otter industrial Pneumonoconioses in the industries of the Colony of Southern Rhodesia, and of Pulmonary Tuberculosis in such industries. Presents to tbe Icgielatipc Boocmblf, toss. Printed for the Government Stationery Ofllee by the Rhodesian Printing and Publishing Co., Ltd., Salisbury. 8! CIIAf'TKK VI. ISVUTUUTIONH AT A*Hk.*TO Ml MB AM) AT Till \V<vt(ir Mtvr Aibcsto*.--The ashestua mines v wiled by thr Commission were the ShiUait Mine, district Bulawayo, and the Uuhilw Mine, district Victoria. The term asbestos is sfiplNi) to a group of minerals wliieh have a final/ fibrosa structure. The must important varieties an- chrysotile or " white asbestos." which is a fibrous serpentine and is a hydrated silicate of magnesium with little iron, and rrueidolite or " blur asbestos," which is a silicate of iron with mailer amounts of magnesium. Chrysotile is the variety mined at Hhabanie and Mashaba. According to Hall iu average composition is: SiO,, 40.49 per eent.; Ai,0,, 1.27 per eent.; Fe,0, and FcO, 2.53 per cent.; MgO, 41.41 per eent and 11,0,14.06 per cent It contains practically no free silica. Chrysotile has a longer and more flexible fibre than the blue variety of asbestos. The country rock is serpentine. Arbesfoeu.--The recognition of the oeenrrw* a - -mm f-rm D? utilmanary fibrosis amongst asbestos worsen is of cofn|wralively recent origin. The first recorded fatal raw was in 19UU, and the use of the term " asbestaaia " to denote the specific form of pnrumonoconiasis resulting from the inhalation of ashrstoa dust was introduced into medical lileiuture only in iiC7. bine* then a considershie literature upon the subject has br*`n produced. The disease has been found and has been studied principally in its aasoeiation with exposure to the dust of asbestos in tbr exploitation oi that material in manufacturing processes. On the pathology of the disease tlie excellent description of Uloyne may be eited.*1 An account of its clinical characters and course and of measures suitable for its prevention baa been given by Merewether* and Merewether and Price.* Asbestos dust is inhaled in tbs form of shorter or longer fragments of fibres and of mall particles. In its general features asbestosis is quite unlike silicosis. The fibrosis is of a fine diffuse type and the sharply defined nodulatioc characteristic of ailieoais is not found. Ultimately in severe eases the consistence of the lung becomes increased and large areas may show fibrous condensation which is tough rather than hard as in silicosis. The pleurae are thickened and commonly very extensively adherent to the chest wall, the diaphragm and the pericardium. There is more difficulty in the transport by tbs agency of " dust cells " of the fibriform particles of asbestos into the substance of the lung than is the eaae with the minute particles of ailieioua dust which eauae silicosis, and the primary reaction to asbestos dust takes place in the smallest terminal air tubes and duets and in the sir sacs. In time, however, the process extends to tbs fibrous frame work of tbs lung and to tbs pleurae. A unique feature of the primary reaction is the formation of what an termed " asbestos bodies." These art bodies of microscopic siae, yellowish brown in colour, elongated and headed and with bulbous ends, the sore of the body being an asbestos fibre. Regarding the practical clinical significance of these hodies Merewether and Price state:-- " They an found in the sputum within a comparatively short time after exposure to aabcstoa dust, and in the absence of clinical or radiological evidence of pulmonary fibrosis their presence cannot at present be taken as indicating anything more than previous inhalation of asbestos dust" (1) Oloyao, S. K.: The Morbid A%atumf mnd Buloift of Atbrtlotit: Tubmlc, Jsljr, Aug., SnL, S9XX. (2; HrrntctWr, E. X. A.; A Hr moraadsw cm Atbctlotis: Tata-frls: Kn., Dae., IM); Jaa.. 19X4. (I) Marewrther, E. K. A., and Pries, C. W.: Keport os effects of Asbestos dust os tbo Imp sad Dm oapprcMioa ia th* Asbootat isdsstry. H.1L Stationery Otbto, Loados, 19X0, AaImsIim UhIii-. 111. i> Ik fount) ill I In* k|il|(iiin vials iiftrl a klmrt Cliiiu ull.i tin-niuiis f usla slni arc sltifhl m tin-r.tih Ihk** The striking ym|tluiii in i)vk|>iiiHa nf gl.tillliilh IlirIVilMlig ilililuuU a. 'In j-r-i-r ~- I linn'll. !. l"-'. , ia-villllr I 11 H III. Mi'l l * i t hr I k|MullMtg of BUrh advanced raM-*, soys; "Usually lin- futul issue is ilrli iiitiiinl tiy the onset uf wain- acute infection with wlueh IIh- n-limiiiiiig Uitdulii.miil lima tissue Ik quite unable tu eojK': this is ronimmily * low gnnlr bnmehu 11111111111111111, but may Is* 5 luluir pneumonia, lirmii'lulis, influenza nr list often 11 sub aruti* tulsrrulir infection ... In the* slssnec of intcrvurnnt iiifichuii*. (hi- fthrud* may pru- pm tu an rxtmne ilegnc ami ilruth i ihim from tlim heart failure An established aslsatuai* ia a serious discuse Like other |iuruiiio'i<kM>nio*cs the duration of i-X)>uure prior to the tlrvcio|iinctif of tile liisritke ia related to the average concentration of dual in Ilk air hmilheil. " l*arti<'iilnra uf thr raan " *>f industrial alnrli lain ureurretl ill England " aeelii to allow tliat with high roneeiitralionk of dust llie miiiiiiiimi |M-rio>l of tune which inuit r|a|sar ln'tween the roniiiieiieeiiient of ex|kaujre mid the prudui'tion of a arrtoua degree of aalawtoaia ia approximately aeven yearn " A few runea have, howrver, occurred with rxiwsnirv of leaa tliao fis year*. Thr radiogiuphir ap|iearunrea in osIs-aliMi* an* in eon fortuity with thr pathological characters of the diaraae and differ in ini|iortaiit rrs(--'* t hoae M-en in atliroBta In the initial atagea of " abnormal inerraae in striatum " the appearaneea in the lung field* an* finer and more reticular than thoar wen in eapiaiurr f ailieknu duat and beeume aaaoeiatrd with a flue gioutid ghnai stippled appear ance (uirtieuiarly in the lower half of the lung Held*, and later * db a shaggy outline of the heart and diaphragm ahadowa and aomrtinies of the lateral peripheral margins of tlir lung fields. It is reeogniaed that ap|iearanee of an abnormal iiienaw in the atriation an ' .tester |>aiiiologieal aigniflranee in |K-r*on* exposed tu the duat of asbestos than in thane exposed to ailierous duat. Tkt Skabmmit ilimtt.--Exploitation of the aabratua drpunita in the Hhabania area began i 1916 to 1917 and the prraent Nhalnuiie mine* are a group of aeveral originally aeparate properties. Tbrrr are four mine* in the group and thr ore mined ia now over one and half million tona per year. Until recently moat of the ore waa mined by quarry-ing but in latter years underground mining baa been contributing a larger proportion of the ore than formerly. The maximum rertieal depth warbed underground is 700 feet A apecial " rut and fill " method of sloping ia used. Waste sorting is carried out in the stupe*. The latter are about 35 feet wide by anything up to a 100 feet long. The broken ore ia wetted in the slopes and quarries and ia hand cobbed in thear situations. It then passes to the four primary milk or " rock plants " and undergoes soceewire crushing! and sortings It a* then dried and subjected to further suerrmivr crushing! and screenings, the lunar fibres of asbestos being lifted off by air auction after each crashing and pswwd to settling boxes until the economic limit of fibre crashing is reached Further grading and separation from foreign material is perforated ia the grading mill in order to effect a final grading of the asbestos in terms of length of fibre. It will he noted that in his report on dust conditions Mr. Psttersoo states that on this mine relatively low dust numbers were found. In the quarries and underground workings the number of particles ranged from 75 particles per cubic centimetre to 880. The highest numbers were found in the two samples taken in the crashing and grading mills In these the number of acieular particles reached 15 per cent, most being under 5 microns in length. Six samples of settled dust on ledges or other surfaces in the sorting and treatment sections of two H nek plants " and in the central grading mill were1 (1) Uomllwr, . It. A.: Lor. rtl 83 obtained by Major Light foot, who rr|Hirta that Ihr mimraU iliitTietl wrra rhryaotilr flhro, aerpcntinc, rarlMinatr, inm ore, and |Hxa>ihly lair Thr projMirtkui of very line ftbrrs waa very amall and generally tIm- rhryxutilc waa in the form of roarar flbrre. This appliea alao to the other const iturnta with thr exception of iron ore partirli-* and to a certain extent carlutnate Thr niilla are apariotu and airy, and it ia everywhere evident that great rare haa been taken by the management to prevent the diaarmination of duat. In the aorting room there ia no viaiblr duat and very little ia viaiblr in tha eruahing and grading dr|>artmenta. Thr general conditions on the mine arr rxtremely good and the medieal service ia highly elllrient, thr huapitai accommodation ia of an exceptional atandard. and an X-ray unit ia inatalled in the huapitai. The mine employed in 1937 an average of IM Europeans. At prraent 26 nrr cmplovcd in the mill*. 14 in qua erica and 58 underground. The native eomplcmrnt waa diatributed aa followa;-- Lndtrarvund 2.235, via.-- 8urfoet 3,262, vis.-- Machine drillera _____ Hammer boya _____ Trammera and Lasbcn__ Other underground ___ 183 81 1,684 287 MUla _____ __ -- 1,446 Other aurfaee 1,816 (36 per cent, of the nativea working in tha miUa are rmployed on ar*t1inl Some 36 per cent, of the nativea were Southern Rhodesian nativea. The t'ommiwion examined only auch European and native rmployeea aa had Invii employed aolely at 8habenie and throe were in each ruar grouped aejiaratrly according aa employment waa in the milla or in quarriea and under ground. Euntptant impioyrd in Jfflla.--Twenty Europeans were exrinincd who had la-en employed aolely in the eruahing and grading milla at thr 8habanle mine*. Fifteen of throe men had been employed for leaa than three yean six months. In nooe of throe 15 eaaea were there appearances of an " abnormal ineroaaa in stnation." In four there was a alightly inereaaed atriatlon of infective type indicative of a Might former tuberraloua tnfeetion. Throe of theae men wen of the aparo physical type associated with that condition, one stated that tubrrruUwix had been suspected in hie boyhood, and he waa somewhat brooehitie. But in no case could any abnormality be found which could be related to tion of asbestos dust Throe men had worked in the mills from eight to nine yean, none showed more than a moderate increase in striation, which was within normal limits but in one the appearances wen suggestive of a alight amount of retention of asbestos duat He waa a man of 28 years of age and of good general nutrition, he was a trifle dinky and complained that his " wind had not been too good for quite a while on climbing or exertion.'' One man who had worked for over 10 year* showed no radiographic or elinieal abnormality. * One who had worked as a shiftsman for five yean and aa mill manager for 10 yean waa in very good health, the radiograph showed no abnormal increase in striation. Five other mill men were examined whose work had not been aolely carried on the Shabanie mines and they an therefore not included in thte Report. European* tmployrd in Quarriti or Undtrgmnd.--Seven Europeans wan examined who had wurked in quarriea or underground at 8habauie only: 1 for 3 years, 3 from 5 to 9 yean, 1 for 11 yean and 2 for 17 yean. In non* of throe ciucs did the rudingruph show more than a ttiodrnte increase in xtriation of a simple type. Of 2 with a service of 17 years, 1 was quite healthy and well nourished but won somewhat emphysematous and complained of chronic eough, the aceond was not of robust type and had an asthmatic history. Neither, however, showed radiographic appearances indicative of sshn^t^ M Examination of Nativei Employed in the Slilli and in Quarrying and Vndrrground .V/iiniifl at the 8habanu Mine*- Till' annual lurnmrr of the native complement on the Hhaluinie mine* is slxiul ti.'i |mt nut, short service " boys" form the gnat majority. The average duration of am in- of natives ............dim it ".tili. TIk- ;;r<.'t'rtioii of native-, with nervier of over five year* who hrvi .orbed only on the Hliuiwnic mini* u lhuh not high. The Communion obtained 197 such natives for rxaiiiihulitm. The dialribution of these and the reaulta of their rxsmiimtiim were aa shown in 1 lie accompanying Tahle. TABLB VII Kicwt lt* or Kwwisatwn or Nativr Kmkuivi.m at Tilt MiiAHAStt Asbkmtim Minks Tnii ( 1 -5 !1 Hiimripiw pfHTUNI NM MIMl M4 1; ;i IfpNftMM . HIMIM 8U4tarft|4rtf 58PMf48ftl Mkllt ! MMII | fU4turB|*il ftppttftM*! Mltdiiw H (** i A.--.Votiifi Employed in .Villi. iii 3 1 -- -- :>* 87 83 4 -- -- 10- JO 18 *1 -- -- i:* 1 1 --* jo* -- Total 111 104194) 7(6) -- i! B.--Xativei Employed in Quarriel or V ndergrvund. I1' -- ` 1 1-- ---- 5* 19 16 2 -- tl 10* 54 52 2 15* 11 10 . 1 -- i -- JO* 1 1 i -- l Total 86 80 l 5(6) -- tl Combinn) Total 197 i 184(94) i 12(6) J i________________ 1 1 11 The Commiaaion is aware that in persona exposed to aabestoe dust appear, once* of " abnormal increase in striation," if of the type which has been noted in such rosea, is of much greater pathological significance than the parallel appearances in persona who have been expo- 1 to siliciou* dust. The films were, therefore, carefully scrutinised with thu consideration in mind. If the results tabulated above be compared with those ahown in Table IV. for natives employed on the thirteen selected gold mines it will be seen that the proportion of cases showing abnormal increase in striation is only rather more than one-third of the corresponding proportion amongst mine natives ss In tb gold mints. Further, in the aeven eaaps of "abnormal atrial ion," notrd amongat the nativra employed in thr 8hahanie milla six wen* uf the " infective " type characteristic of a mild latent or arrested tula-rculous infection and the appearances had none of the etigmata of aabralaaia In only one of thear seven a u.iil .mplc. 'r v l;t nine ye*ra' wr.'w a* arter. the almonnal inereaae in athation vaa of aimpie type and the appearaneea were com|>atitie with thane of a commencing aalwatuaia bat he had no eomplaint of rough or ahortneaa of breath. In one or Iwo other caare there waa a alight increase of fine atriation which was euggeativr of alight retention of aaheataa duat but no definite ease of early aabeetaaia waa found. The number examined in the critical period of from f to 14 yearn waa auffleiently large to have given definitely positive result* had theme been present. One eaar of suspected quietly- active tuberruloais waa detected amongst the underground natives, he had had nine years' service. The sputum, however, waa iouiul to U i:-.gali\r f.r tl.c tubercle bacillus. There is no doubt that a certain number of definite eases of aabeatnaii have arisen on the Hhalwnir mines in the past Dr. F. W. Rimson. of the Department of Pathology of the South African Institute of Medical Researrh, Johannesburg, published in 1928 a report on four rears of ashralusM1 for which thr material had been forwarded by Dr. Ireland, the medieal officer of the Shahanle mines. The management of the mines has for many year* devoted much attrntinr towards minimising the risk from ssbestoa duat and the medieal officer has been actively attentive to the possibility of the occurrence of rases of asbeatosia. In this connection Dr. Inland has submitted the following statement to the Commimioo:-- " The subject of aabestosis has, for severs! years, beer, of consider able interest to me and at far buck as 1926 I submitted my first specimen nf lungs removed at autopsy, to the South African Institute for Medics! Research for histological investIgation. The lungs in this ease allowed, mirroaropirslly, a fibrosis quite distinctive from anything 1 had previously seen. However, it waa not until 1929 that I began to file records of further investigations and by 1932 I had 16 worded. Between 1932 and 1938 I have had many investigations made and only two of thee* have shown any pathology relating to aabestosis. Two of my eases sub mitted in 1926 and 1927 have been the subject of a special publication made by the Institute, to 1928, and published In the British Medieal Journal the same year. Of the 18 earn investigated, 10 were negative in every respect, 3 showed ` curious bodies ' without signs of a fibrosis attributable to asbestos duat Five casts wen definitely described as pulmonary aabeetaaia, the first being in 1928, when there was very little concerning the pathology on word, so that no definite eoneluaione were reeehed until 1927, when my second case waa Investigated by the Institute, and when the fibrosis waa definitely amociated with the presence of asbestos bodies. 1 have one eaae on record in whieh aabestosis was found la conjunction with pulmonary tuberruloais. I shall refer briefly to the reports by the Institute in connection with those specimens in whieh asbestos bodies were found either with " no fibrosis "or" fibrosis " not attributable to these bodies and those definitely reported as aabestosis. Case 1, 1926.--An adult malt native who had worked for 12 months In an asbestos mill, who disd of pulmonary tuberculosis. `Curious bodies' were found, but they were not associated with the tuberculosis or accompanying fibrosis until 1927. At the time of examination the fibrosis was attributed to silica Com 2, 1927.--A ease of pneumonia with two years' aerviee in the mill. There wot evidenee of fibrosis and aalicslos bodies were identified No evidence of tulicreulosia The findings were suggestive of changes resulting in the Inngs from a dust occupation. Core 3, 1929.--There was a well marked uncomplicated pulmonary aabestosis. (1) Simaoa, t. W.: Pslwesary Arhtiiotii Is Bontk Africa. Bril. Med. Jl, Sth May, IKS. f'ojf 4, 1939.- Two month*' servin' A*l*'*iu* ImmIh* were found which hod nu relation to the fibrosis dcwrilN-d u-i romw-iiiiint to a chronic bronchitis. Ciut 5, 1931 - Five yean' service in the mill. Died of pneumonia .1.1! *< r: !*!; ,)'l. J<1 it*hlnl i.... ,.f '..Im.Iih. .'iff At**tlM bodim Mttv found Cate 6, 1929.--Asbestos Isslics were found toil no flhnMM. Had one month* nervier, dying of abscess of the lung fas* 7, 1930.' Five month*' wrvHv, dying of lironrho-pm-ntimnis. Anlxntim I**lie* were found in the alveoli, lull no *igll* of flbnwi*. Catt 8, 1931.- Ilivd of pneumonia after t!l month*' nervier in the mill A*l>r*to l**lie were found and a very Might degree of flhruaia. There wa* surprisingly little reaction in the lung though a!>r*t<*i bodies were nunoioui. Since 1933 I have two further caw* to reeonl, vix- Casr 9, 1937.--Case of generalised tuberculosis Fifty-eight months' service Section of lung alwmi-tl caaeating tul* reulo*i* and a*l>e*lo*i*. Cast 10, 193M - ('a*e of ilouhle pneumonia with 27 month*' service a* a 'boas huy* underground. Reported a* tubereulo silicotic with aalwwtos bodies in arvcral areaa. It ia interfiling to note that moat investigator* *tate iiiat **mptonut of pulmonary aalwstuaia in Europeans do not Income oidinl Uforr five year* of ex|iOBure. It would appear rather extraordinary that such advanced pathological change* should become evident in native worker* before the appearance of any symptoms The Inugisit rase of exposure on reeonl among our natives was five year* and tlien only alight Abiotic change* were found. My worst case* were of one to two yran' exposure. This tends to suggest that some other factor may lie influeneing the fthnwi*. 1 have no record of any ease with rymplumi in any way suggestive of pulmonary ashestuMia. Reviewing the past 17 yean that I have been Medical Officer to the Shahanie Mine, I have no record of any European, allowing symp tom* or signs characteristic of aahratoaia. Two of our longest aerviee mill men Mill show a clean sheet, elinlealiy and radmlogteally." Dr. VI. K. Blackie, no his visit to the 8hahenie mines on 9th March, obtained from Dr. Inland the lungs of a native who had just died from tuberculosis and has submitted them to examination. He reports aa follows:-- " Some: Oadxa. Clott of Mint: Aabestcw. .Value* of Work : Under ground hoes boy since 1933. He had, however, previously spent two yean on a gold mine. The mieroeropie appearanees wen those of tuhemuloua broncho pneumonia with caseation and commencing cavitation. The lung time waa also examined histologically. For thia purpose a aeries of six blocks wen prepared from different ana* of the lungs and sections pnpared from each block wen stained by the following methods: Haemalum and Eaain, Prussian Bloc reaction with Cartnalum countertain, van Oieson and hacmatoxylin, Oallcgu, Cclcstin Blue, Eoain and Light Green. The mlient features of the eections wen:-- (a) Areaa of tuberculous broneho-pneumonia. (b) The presence of numerous asbestos bodies. (e) Black opaque particle* probably derived from a brittle element in crude asbestos. (d) An absence of diffuee interstitial fibrosis. The eahesto* bodies wen scattered singly and in clumps throughout the section*. Then waa a general tendency, however, for the bodies to be eongrvgeted in greatest concentration in relation to the tuberculous m lesion* It i* generally slated that the pulmonary reaction to aalnatna Uslie* takes the form of a diffuse interstitial flhmsia In order to demonstrate this feature in the material examined special flhroua tiue atatna wen employed. Thrar brought out fori of mild fllironllular reactions in relation to aggregates of pigmented cells, with areas of peribronchial aim aepiai nbtuai*, hut i> i-. ..oti v-.r'l; tlirt *br diffuse interatitial flhruaia of pulmonary aabeatoaia waa n * denmuatrated. Thu* it may I* aaid that in the material examined there appcnrrd to he no dime! relationahip between the flhmua tiaaue rliBiigea in the lungs and the presence of aabeataa bodies." The Commimion ia in agreement with the view that unleaa a significant degree of flhruaia haa heen produced by the inhalation of aaU-atoa dual the prrarnee of aabeataa bodies in a tuiiereuloua lung doea not provide evident. that ti* ut-t t of tu'-erruh u* Ir fee*inn haa he n facilitated by exposure to aaiicatoa dual. It would, however, note that one of the eaara dearribed in l>r. Ireland'* statement in whieh definite aabeatoaia waa found to be aaaoeiated with pulmonary tuhrreuhmis oreurred aa late aa 1937 in * native with four yean and ten montha* service. While, therefore, taking the cvldenee provided by Mr. Pattersons dm atudiea and by the investigation of the Commiaaion together with that supplied hv Dr. Ireland, the Commiaaion ia of opinion that no mgnilicaiit nui. '*- ' raara of aabeatoaia ia likely to he produced under tlie u i'ujtatlonal conditions whieh have heen developed under the present management, it appears to be possible that occasional eases may arise. Aalieatoa duat ia a dangrrmia dust with insidious and delayed effects, and all possible steps should be taken by the management, particularly in respect of milling operations, to perfect the measures whieh have been adopted to prevent exposure to it. Aa already Hated, the Commiaaion ia also of opinion that the measures recommended for the detection of eases of silicosis and tuberculosis on gold mines should hr applied to the detection of eases of tuberculosis and poaaible cases of aabeatoaia or ailieoaia on aabeataa mines. Tkt Slatikata Hint (ftathe Group).--This mine is in the Victoria district. It ia under the aame group control as the Bhabanie Mines but ia a much smaller proposition. The mineralogieal characters of the rock* exploited are the same aa at Bhabanie, the ore ia recovered by quarrying, the only work done under ground ia tramming to tha ore-bins on the first level. The mine employi 14 Europeans of whom three are employed In the mill and four in the quarry, the remainder being employed on other surface work. Four hundred and fifty natives* are employed in the quarry and 60 in the mill. Examination of Europeans.--Only seven Europeans who had worked only on asbestos mines were available for examination and four of these had been employed for a few months only. The results in these cases were negative. Of the remaining three, two with service! of 4 yean and three months and 14 yean, respectively, in the quarry wet* healthy and well nourished and showed no radiographic alxionnality. The third with 1- yean* service in the mill had some amount of emphysema and bronchitis, lie waa, however, of the obese pyknic physical type in whieh that condition is apt to develop in later middle life: hr waa 59 yean of age. Ilia radiograph showed no definite indications of sslwstoaia In one Kuroja-un umhreiound employee who had had 14 yean in the Mashnlin quarry, but hud previously had nine yrnn' underground service on the WitwHti rsrund with lime yenni on machine drilling, u welt imnkcd degree of simple silicosis wu detected. He was in good condition and fit for ordinary work. M Etamw-iluiH of S'nliic Fifty thru lmli*i who hail Worked only on shU ultra mint* were submitted to Kjimiimtton with the following result - TAHIjK VIII 2!. ' i Ty - * K * ' **. rut*. i**` - ** 11i.i... f*i i i... Mamhaha Mink fun tgrtrir* NwMf >fHM< VMJMl --ftofil MMMWM i itasmil IffMI to MrtMMto Mtonifr** IMMfAW M Mkfilltt * Mini* UtoXmlt IU4burp*to IMMIIMII MMIraOvo nt |gfefttUkU l ft* 10* 15* Total .p1 5* 10 + 15-+ Total Combined Total A .Vdiitrc Emplnyui in . ti i;. 15 -- ii 11 -- -- j _ -- 3 3 --; -- 31 31 i 1 B--Satilti Employrtf ia Quarry. 11 Om 2 -- 9 9---- ft 5 -- 65 -- 22 21 -- -- . 53 52 -- -- -- -- -- -- -- -- fl 11 11 Five additional eases were examined who had worked in Southern Rhodcalon gold mine* a* well a* in asbestos mine*. Of there one ahowed a alight degree of silicosis; be had worked for eight year* in the Maahaha quarry and eeven year* in gold minca; one ahowed aetive tuberculous, he had worked for 15 year* aa a hammer boy in Maahaha quarry and eight yean in gold mine*. The remit* abnwn in Table VIII. for the nativra who had worked soMy in aabeatoa mine* and the conclusions to be drawn correspond at all points with those found in the Shahanie mine*. No raw of definite aabestoaia was detected either in the mill employees or the quarry workers, although 15 had worked in one or other for over 10 years up to a limit of 19 years. There was one ease of suspected tuberculosis in a native who had worked for 13 years in asheatoa quarries and 4 years and 10 months in the Maahaha mill. The single specimen of sputum forwarded was, however, negative for the tubereule bacillus. The Commission was informed that from time to time a few natives had been taken out of the mill for chest complaints, and had their work changed or had been discharged at their cwn request. The Mashaba mill ia old-fashioned and there ia a good deal of visible dust in the air. Steps should be taken by the management to improve the control of dust in this mill. w Thk Wanmk ('mi. Mink. Tkr Wanku Coal Mint .--Then' an- two collicrmi in tin- Wankir coal area. At No. 1 colliery the seam 3ten 300 fri U-Jow the nurture and huu * tiiwknees of shout 10 feet At No. 2 colliery tlir warn has a thickness of 30 to 30 feet. 1 iUfcUi&i u, III if. ' -I plILt bi,u StCw. Uininf la ratirely in coal and alwut 6,000 lima are mined daily. From an analyaia aupplied by the management it appears that the amount of free ailiea in the coal prior to ignition ia of the order of 0.4 |>er rent. The mine ia wall ventilated, Housing, aanilation, mediral attention and general care of the native* arc of a high (tandat'd. The mine employed in 1637, 137 Kuropran* on aurfaee and underground and 3,103 native* (average at end of month). The native complement waa diatributrd aa follow* (daily average):-- ( dcrpiv.ud.-Miul.mi driller*, 153, hammer hoys, 10; trammer* and lashers, 376; other underground, 372. Hnrfati.--1,351. Two-tbirda of the native comnlement are Northrm Rhodeaian native*. Examination of European Employers.--('linieal and radiographic examinationa were made of thorn European underground employee* who had worked aolely in coal mine* either at Wankie or elaewhere. Of them there were 11--all were healthy men and were tit for and per forming ordinary physical work. Two only had worked aolely at Wankie. The radiograph of one, aged 55, chowed aome amount of ** abnormal tnerraar in atriation " aaaociated clinu-*iiy with chronic bronchitis. He stated, however, that he had had a chronic cough ever since he had been gaamd during the war so that hi* case waa not uncom plicated. he had had 23 years' work on the surface rrusher station st Wankie. The second, aged 44, had liad 14 yran' service os o roal miner at Wankie. He waa of " pyknic " typa, and getting obese; he had emphysema and slight bronchitis, a condition whieh persona of this physical type are prone to develop in middle life. His radiograph thawed no abnormal increase in atriation. In the remaining nine eases the greater part of their work had been per formed elsewhere in Scotland, England and Wales, or in the Union of South Africa. Two were mine officials and showed no abnormality. The other seven were long service miners with ages ranging from 41 to 49 and with an underground service of from 23 to 34 years. In six the radiograph bowed aome amount of abnormal increase in atriation suggestive of a minor degree of fibrosis, but in no eaae was there evidence of nodulation or of areas suggestive of anthraeo-ailieotie consolidation. In one or two there waa aome emphysema but all were healthy men fit for and performing ordinary work. Examination of Nativa Employees.--The 116 native employees -xarained had worked only at the Wankie colliery and formed a random sample of those most liable to be exposed to dust, namely:-- Machine and hammer or jaek hammer boys, 44; screening, 27; lashing, 40; and others, 6. The distribution of these 116 natives according to duration of service was ss under:-- DtIW at bMu. IMr rmm. u fmn. 14Itrfttofi. itumtoil. M FUN m4 mt. Number examined------ Radiographs showing sh normal increase in striction .... .. i ____ ! 3 82 21 41 Other abnormalities -- | i i > i1 10 I 00 The general physique of these native* u very good. One aative only, included in the group having 10 to 14 year*' wrvire, ahowed significant abnormality. The radiograph allowed a well drfliml di nin' and moderately eatenaive opacity placed roughly aymmetrieelly in ttw suh- ^j'Ual of '*< tni.j* amt fuli-mlintf to the periphery. The Rp|M-urunrr sug- geatad bilateral areas of arreatcd or latent tuhrreuloai* aaaoeiateil witn eonw qneni local retention of coal dual. The native waa healthy, rn-et anil well nouriiilii-t! and had no complaint*. The appearance described ia familiar in caw* of coal dual retention with poaaibly alight Ahroaia. With thia exception the radiographa of theae native* ahowed no aignifleant abnormality. In five only there waa a moderate inerraar in st risti<*n of infective type indicative of alight old arrrated tuhercuhmi* hut thia occurrence in a ample of tha sise taken waa to he expected. The 10 nativee who hail had over 20 year*' service were all middle aged or elderly. Two showed evidence o( very alight old healed tuhcreuhmi* but were in good health and fit for ordinary' work: one had chronic bronchitis and one alight emphyartna. With the ainglr exception of the ease Arat mentioned there waa no indication amongst these native* of any aigniAeant abnormality. Many of those in the 10 to 14 and IS to 19 yean' period* of service ahowed radiographically an " ideal " normal thorax. Th* appearance* found in thia sample ot c*scs mad* ti.< C .:"'uu~a*i; to conclude that coal mining at Wankie ia not productive of silicosis. Ckromt Working.--The ehrome quarries at Selukwe Peak and Railway Block, near 8elukwe, were inspected by the Commission but the character of theae workings did not Biggest that they are at all likely to produce esse* ot silicosis and no detailed investigation waa, therefore, carried out. Cuitthuion.--The Commission desires to express Its cordial thanks to all Government officials. representatives of the Mining Industry, mine officials, miners and others for their active cooperation in forwarding the investigations conducted in thia enquiry. Aa Advisers:-- A. a ROME, B. LIOHTFOOT, H. 8. PATTERSON. L. O. IRVINE, Chairman. C. W. ROBERTSON, Member. W. K BLACKIE, Member. m AWKNMX /. rilicorir in hoitiikhn riiohkhia. RxrnRT SV THK HrS-OoMMITTK* Al'IltlNTICI* B\ Tit* IUmHiMU AMD R.t r Ths Rub-Committee consisting of mir rvprvurm stive from wh of tbs Chambers of Mines in Rout hrrn Rhodesia waa spiminted in May, 1937, to investigate and report aa far aa possible on the incidence nf Kilimaia in thia country and make reeommendationa to thr Chamls-rs in emmeetion with ita prevention and control. In connection with our investigations all tninrn on 'hr Cam and Motor and the GloU- and Phoenix Mines have been examined Isnh mcdinilly and by a rsdiologist. All X-ray negatives were amt to the I'lilliiaia liun-au in Johannesburg forlnterprelation. The result of thr examination of 92 mm ia aa fullnwa:-- Suffering from Riliroaia . 11 (Cam. 4; Globe, 7) No sign of 8iliroaia or Tulicreuloais . 81 An anal.vaia of thr career* of the 11 men affected, discloses that:-- 1 worked for 16 years on the Rand. 14 ........................ 11* ............... ,, 9 * * H 8 years in India 1 4 Cornwall 1 I ,, ,, Sort item Khodaaia f 12 yesra in coal and iron mines in England (10) years in N England minesi j 1 year on Rand f Total 9 While it is not proved that these men definitely contracted ailieoaia outside Rhodesia, it may be stated that it ia extremely probable. Of the remaining two cases, one has worked for 26 year* on the Globe and Phoenix Mine and on no ot|er mine, and is suffering from a " moderate degree The other has only worked on the Globe and Phoenix among the larger mines, and that for a period of 10 yean, but he has also worked for 15 yean on small mines and quarries. The full period of 25 yean has been spent in Southern Rhodesia. He is also suffering from a " moderate degree of silicosis." Then are, then out of nearly 100 minen examined, only two who have definitely contracted silicosis in Southern Rhodesia. Of the men examined, it is worthy of note that there are 13 men with underground service of from 16 to 33 yean, who so far are not sufferer* from silicosis. It should be noted that of these, 11 are on the Cam and Motor, when the position seems more satisfactory than on the Globe and Phoenix, and when 8 of the 11 hare worked continuously tor 11 yean or more. Conclusions.--While it is proved that silicosis does exist in Southern Rhodesia, the position is not serious. The conditions under which silicosis sufferers worked in the past hart hem much improved on, and It appears therefore, that healthy miners may rraMnahly expect at least 20 yean' service lie fore developing ailieoaia in the slightest degree. It appears to us that in one ease of silicosis, the period before infection might have been lengthened considerably bad the man in question been of better physique. 92 RffoiiniirWe recommend 1 That in the raw of thr dec|>er minot, Haw mines should tubjrct prospective miner* ami leu mer miner* lo triet medical and X ray culmination, and ahould only engage thaw who have atfaetnrily p***ed this examination. 2. That facilities should be granted io the mine* by me (i.etitiu Mrdira) Authoritica through which miner* and learner* can undergo X-ray lamination* at any Government lloa|dtal where X-ray appamtu* i inatalhil, an payment of a nominal fee by the mine eoneemrd. 3. That failing the appointment of a Government Radiiilugiid qualified to interpret the photograph*, the Cltambrr* of Mine* enter into an arrangement if possible, with the I'hthixi* Bureau in Johanne*lHtrg under whieh nur pliotographa ran be interpreted for u*. 4. That after TO year*' mwlerKround mining on the deeper mine*, all miner* ahould be examined radiologiculy oncoa year. 5. That while the ao-eaHed Ante-Primary atage of 8iUcoai* doe* not eauae diaability, it ia nree**ary to eliminate the secondary atage aulferer, i.a. the man who may he *u(fering from tulwrruluaia aa well aa silicosis. i. That although tuherculnai* may not be directly traceable to the man'* employment, yet should future examination prove any underground employee to be Buffering from tuhcreuloai*, aa a direct rrault of ailieasis, or from ailieaaia in the areondary stage, the - a JJ! ju-h ;uff-rrr e penaion of 10 per month to a maximum of 500 7. That aeetion 103--Mine* and Minerala Act, 193.V Clauae 1 (a), (b) and (e) ahould he altered to read " tuberculoma or miner*' phtlii*U with tuliereut *ia " instead of " miner*' phthbd* or tuhemiloais " aa at prmrnt. We would atrma that of these recommendations the moat important ia the strict medical examination of all men for underground work (vidt Roeomnendatton 1), and would auggeat that this ahould be brought to the notice of the authorities in eharge of the mining aide of the Technical School at Buiawayo. 1st November, 1937. DIOBY V. BURNETT, Representing Thx Chambrb or Mtxu, 8xusau*T (Ineorporated). 0. A. DAVENPORT, Representing Rhodesia Chambcb or Mona. 93 APPKSDIX II. Phahanic Mina, Rmoouiam axo Gknuul Aksutus Co*tv>*ATux, Ltd. Shabani* Mina, Shabani, *.*8th Deecmbsr, 1931. The Consulting Engineer. Rhodesian A General Aabaatos Corporation, Lid., H O. Box 1100, Bulawayo. Dear 8ir, A8BE8TOSIB. 1 have pleasure In submitting herewith my report oo the subject of asbrstoais on the Shabanle Minaa My arnriee, aa Medical Officer to this group of mines, extends for a period of over 16 yean. During thia 1 have Interested myself in the dual problem in tlte mills and mine in Ita relation to pulmonary affection*. On the lOtM May, 1932, I submitted a report giving full details of the mire and health records of all European millmen who had been subjected to our highest concentrations of dost. 1 derided to conffne myself to thia group of employees as in all other occupations on the mine the dust problem appeared negligible. At thia stage 1 came to the conclusion that no genuine eaar of pulmonary aabestoato or any form of fibrosis of an occupational nature could be ascribed to the asbestos mining industry of Shabani. Stun i:>,U 1 have cuultnued my investigatkms, clinically and radlolofieally, in iH-sith and disease, and bare satisfied myself that there are, at the moment, no indications of aabestoaia hemming a mcnaet to the industry in Shabani. During the present year 1 bore X-rayed all millmen in the service of tbs mine. These Alma have been submitted to the serutlny of Dr. Irvine, Chairman of the Miners' Phthisis Board. Johannesburg, with entirely negative results. It has been my. experience that the millmen. In general, have maintained a vary high standard of health and in no ease has there been any symptomatic indication of a gradually developing fibrosis. Weights have been maintained and in many eaaea then has been a considerable gain; than baa bean no dyspnoea or lassitude or other signs of pulmonary involvement. Soma of the men with long service have at different times presented themsehrm at the Miners' Phtbtoto Board tor examination and I am not able to record a single instance when a " Red Ticket" has not been Initially granted or withdrawn on re-examination. During the present year the system of radiologieally controlled medical examination has been extended to underground workers. It is propoaed that re-examinations will be conducted at intervals of one year so that in tha course of tha next few yean it will be pondble to review the subject from mining as well as mill occupations. It to interesting to note that among our minen we have several with ante-primary silieosto. Them men an required to bo re-examined every two years either by the Minen* Phthisis Board or by a Medical Officer nominated by tha Board or Medical Director of Southern Rhodesia. In no eaaea have there been any aigns of development to a further stage. In conclusion, I can, without hesitation, say that no anxiety need be entertained in regard to the asbestos mining industry where adequate provision to mule for good ventilation and the protection of the millmen by the use of uitubir dust filtering respirators as are uw-d on this property. Youn faithfully, A. J. IRELAND, Chief Medical Officer. ^ u v ` 1 i $ i ^ | 94 APPKSIU.X III. SrcrlMKN Fow Iu4>iiuti\u Minium or RrixiauiMU Isduiixai. r,;r I.T: !' *{' |\VIu-! ,7|i...- ffjfdasalary Salt: -- In this form " N.T.," "HJIami " M K " indicate rrapwtivily tha appearances of "Normal Thorax," " Hlialit inrn-u*e In linear striutiim " and " Moderate inerraar in linear alriation," " HIT" indieatea a "well marked" and "(J.A." (" generalised alxirira tion ") a "very well marked iiu-nasr in linear atrial uni " " G.A.p.aM." indirate* a " generalised sboriiatioti with partial amall Mottling " whiehjs the earliest unequivocal radiographic appearance of a definite adieuaia. " 0 8.11." " O.U U." and " U.L.M." indicate respectively a generalis'd " wnall," " medium "or" large " mottling, indicative of a " moderate," " well marked " or " very well marked " degree of nodular silicosis. " p.inf " indicates. in any of the above type* (eaeept the Normal Thoras '1, that the radiograph ahows a mudifieation of the type ap|earaneea indicative of an atreated or latent infective element. Appear*nera of larfrr diffuse opaeitiea indicative nf.fibroid consolidation or aocfrative of active tuberculosis, if an attempt is made to diatincuiah these, are also provided for. Such appearance* may accompany any of typea 1 to 16. Other complication* causing diffuse opacity or other abnormality may be noted in the column " Pinal Classification." The auhatantive elaa*ifie*tion la indicated by a plain stroke, ; complicating condition* such as appearance of infection arc indicated in brackets, thus Cl, so that uo uwr ia duplicated.