Document d3Yn3rd7wQV6ZyKGYq5QQDe6

FILE NAME: Asbestos Cement Pipe and Sheet (ACPS) DATE: 1975 June DOC#: ACPS019 DOCUMENT DESCRIPTION: Journal Article - Cement, Asbestos, and CementAsbestos Pneumoconioses Cement, Asbestos, and Cement-Asbestos Pneumoconioses A Comparative Clinical-Roentgenographic Study Giovanni Scansetti, MD; Giancarlo C. Coscia, MD; Walter Pisani, MD; Giovanni F. Rullino, MD The incidence and characteristics of cement-asbestos pneumoconiosis were compared with those of asbestosis and cement pneumoconiosis in three homo geneous samples of cases. The clinical, functional, and radio logical features of cement-asbestos pneumoconiosis are similar to those of classical asbestosis, but the observed changes are less common and occur after a longer exposure. J A bout two thirds of all the asbcs' \ - tos produced in the world is con sumed by the cement-asbestos (CA) industries.1- Medium- and short-fibered serpentine (chrysotile) is the most widely used variety, whereas long-fiberod amphibole (crocidolito) is used less often. Selection of substance depends on whether it is desired to endow the finished product with greater flexibility or, in the case of crocidolite, strength and resistance to acids. The asbestos is mixed in a propor tion of 15% to 20%- with artificial Port land cement that consists of calcium silicate, tricalcium aluminate, and tri calcium ferrite. Portland cement also contains from Iff' to 5% of free silica (SiO.) and smaller amounts of other Submitted for publication Aug !>, litTI; ac cepted Sept 21. From the Institute of Occupational Medicine of the t niversity of Turin. Italy. Reprint requests to the Institute di Medieina del l.aeoro, I'mversiti! dl Torino, 2!t, Via /.urotti, lOl'di! Turin, Italy (Or Scansetti). compounds, mainly CaO, as well as aluminium, iron, and magnesium oxides. Exposed workers may develop a combined pneumoconiosis in which fi brosis caused by the asbestos, mostly in the middle and lower zones of the lungs, is associated with rounded le sions and hilar adenopathy attribu table to the silica.-' The pathologic changes are there fore produced by the partly unaltered asbestos fibers in the mixture1'and partly by the cement that has been shown experimentally to have a sclerotic effect on the peritoneum in the rat when its content of free silica approximates 5%." Nordmann and Sonnenberg* have suggested that the enlargement of the hilar lymph nodes may be due to the lime. The incidence of this pneumo coniosis, usually diagnosed as asbes tosis, was found to be 5% in exposed workers in CA industries near Naples' and 12%11or 12.9% in CA fac tories near Casalc." DeRosa et al: investigated the dis tribution of the workers with asbes tosis in the various workshops. They found that 50% of those employed in preliminary processing of the fibers and 15% to 18% of those employed in dry manipulation of the finished product were affected. Rubino and Scansetti-' found that the incidence of asbestosis among ex posed workers in CA industries was one half of that found among exposed workers in brake and friction mate rial and one third that of w o rk e rs in asbestos textile factories. The incidence of asbestosis is very high in India"' (27% of exposed sub jects) and in Egypt,11 where 81% of the workers exposed to CA for more than 20 years were found to he af fected, hut low in West Germany where 23 of 4,500 (approximately 0.5%) exposed workers were found to he afi'ceted and were awarded com pensation for asbestosis from 1958 to 19ii7.' Bohlig also found that the inci dence of asbestosis was 11 times lower in the CA industry than in other industries in which asbestos is used. METHOD The purposes of this investigation were (1) to a sc e rta in the incidence of CA p n eu moconiosis that, as indicated aboxe, seem-, to dilfer widely in different countries, espe cially w hen com pared to th a t of elas.-n al asb esto sis and (2) to define the eliniea! fe a tu re s of this pneum oeoniosls th a t is a ttr ib utable to the combined, although dbfcr< ut, action of tu o d u sts-o c m e n t-a possible cause of silicosis, a n d - a s b e s to s - th a t is present under the form of asbestos a! rs. throughout the entire m anufacturing pro cess and in the finished product. Three sam ple groups. . aeh num ber.ng 100 subjects, w ere exam ined. The first, de nom inated the cem ent o r C group, a . . . -e- looted from a series ol Xl.l vor.-..rs e x posed to the dust form e,! m 'uarr-. m arl for natural cem ents or in the a- fa clu ro of n a tu ra l or arp.tn-i.il c on t.t' T he second, d e n o m m a u d th e c, : - bostos or CA group, was s. '. c u d freo. a se ries of fil'd w orkers em p eyed in i \ I i 1- to n es. T he th .rd . deni>m:t`a'.> d li . - or A group, w as scl. .te d :r m a : XU w orkers e m p lo y 'd in a-u u faetorii s. S tarting from the e in., t . corresponding sufiy.. t m i ... a ' > 272 Aich Environ Health/V oi 30, June 1975 Pneum oconioses Sea Croup CA C A Table 1.-- Physical Findings Clubbing Slight 3 1 8 Severe 0 0 2 Cyanosis Slight 12 1 1ft Severe 0 0 3 Bronchial Rales 11 4 4 Crepitant Basal Rales 8 7 13 Pleural Friction Rub 3 0 5 Table 2.-- E lectrocardiographic Signs of Right Cardiac Impairment Group CA C A " Pulmonary" P wave 1 4 3 Delayed Right Intraventricular Conduction f' Focal Bundle X Complete Bundle Branch Block Branch Block 2 2 1 1 2 2 Table 3.-- Respiratory Function Tests* VC FEV, 0 FEV, 0 Group CA C A theor VC 69.80 75.95 66.53 theor FEV 69 97 72.93 66.53 VC 69.49 65.19 69.88 * VC and FEV, c are expressed in percent of the standard value established by the European steel and coal community. other series was selected by comput erization so as to obtain groups of three cases of equivalent ( 5 years) age and du ration of exposure. A total of 33 subjects in the series exposed to cement dust were dis carded, no corresponding subject having been found in one or both of the two other groups, thus leaving 100 series of three subjects each. Tile mean age of the three samples ranged from 51.5 to 55.5 years and the mean duration of exposure from 18.5 to 21 years. Group Mean Age, yr Mean Exposure, yr CA 54.5 19.9 C 55.5 21.0 A 55.5 18.5 The three groups were compared taking into account the incidence of various physi cal (clubbing, cyanosis, bronchial and crepitant rales, pleura! friction rub), elec trocardiographic (evidence of cardiac im pairment on the right such as pulmonary P wave ami delayed intraventricular conduc tion on the right), and roentgenographie i I'Mts "extended" International Labor 01'lii't- |II.O| classilication) limlings, and the im-.in values oliM-ned in pulmonary func tion te-t-. (vital vapaeitv |V ('| and forced e x p irato ry volume | I'KV ,| expressed in IHUenl ol the stumbiril values established b\ I'.- l''uiMpe:in i on I and sir.-I rnmmiiiiil \ , I i'\ . VO r RESULTS Clubbing of the fingers and cya nosis (Table 1) were more common in the A group (10% and 19% of the cases, respectively) than in the C group. Cyanosis was present in 12% of cases and clubbing only in 3% in the C.A group. Crepitant basal rales, a character istic symptom in ashestosis, were also more common in the A group (13% of the cases) but were found as often in the CA group (8% of the cases) as in the C group (7% of the eases). Symptoms of bronchitis were espe cially common in the CA group (11% of the cases) and were found less often in the two other groups (4% of the cases in both). Pleural friction rub was found only in the A and CA groups (5% and 3% of the cases, re spectively). Electrocardiographic signs of car diac impairment on the right were uncommon. Their incidence did not dill'er significantly in the three groups (Table 2). Right ventricular hypertrophy or strain was never ob served. The results of pulmonary function studies are shown in Table 3. The type and severity of the observed changes differed in the three groups. Mild, predominantly obstructive im pairment of pulmonary function was found in tlie C group and more severe impairment, of a predominantly re strictive type, in the A group, in which the FEV, ,,/VC ratio was low but still within the normal range. The pattern in the CA group was similar to that observed in the A group, hut tiie degree of impairment was less se vere and of a less clearly restrictive type. The roentgenographie findings (1968 IL0 classification) are shown in Table 4 in which only the type of the shadows, hut not their extension and profusion, is considered. Table 4 shows the number of positive cases. As customary in this type of analysis, cases showing only minimal (0/1) pro fusion of the shadows are omitted. Figure 1 groups the cases of rounded shadows, irregular shadows, and those in which rounded and irregular shadows were present together. Irregular shadows were found in three quarters of the cases in the A group and in two thirds of those in the CA group. The incidence of typo s was about the same in the two groups. Irregular shadows, mostly (28 out of 33 cases) type s, were present in one third of the C group. Rounded shadows were virtually never found except in subjects exposed to silica, even if exposure was not severe. They were found in 10% of the CA group and in 18% of the C group. None of the subjects in the A group had rounded shadows alone. Three had rounded shadows associated with ir regular shadows (the group with mixed shadows also includes cases classified as grade 0/1 of profusion). Types u and r were not found in any of the three groups. The profusion and extension of the observed roentgenographie shadows are shown in Tallies 5 and il. For prac tical reasons, the findings are grouped together as follows: prolu sion-low (0/1, 1/0, 1/1), medium (12, 2/1, 2/2) and high (other classes); oxtension-small (two lung zones), me dium (four lung zones), and groat (more than four lung koiio-a . In the oaso of irr. gnlai had"" especially type t, high d< grv. - o! p'o- Atch l nviton Hoalth/Vol 30, June 19/5 Pneumoconioses/Scansolti et al 2 /3 j . ;j - j i . 1 . ; fusion were much more common in the A group. Oases elassifieii as types s ami t with a high decree of profu sion of the shadows were found in the CA group, although not as often as in the former group. No type t with a high degree of profusion was found in the C group. Rounded shadows in the A and CA groups never showed a high degree of profusion. Two cases of rounded shad ows (type q) in the C group showed a high degree of profusion. The incidence of roentgenographic changes in the pleurae is shown in Fig 2. The conclusion seems war ranted that, especially from this standpoint, CA pneumoconiosis is similar to classical ashestosis. Obliter ation of the costophrcnic angle and thickening of the parietal pleura without calcification were found to gether in about one quarter of the cases in the CA group and in about one sixth and one quarter, respec tively, of the A and C groups. Calcifi cations of the parietal and diaphrag matic pleura were found in 7rc of cases in the CA group and in 97. of cases in the A group. All these changes were much less common in the C group. However, one of the cases in this group had calcifications of the parie tal pleura and another calcifications of the diaphragmatic pleura. COMMENT Our findings point to the conclusion that CA pneumoconiosis is similar to classical asbestosis although less ad vanced at an equal duration of expo sure. 1. Respiratory or cardiorespiratory insufficiency was found in a number of cases in the CA group, although less often than in the A group, but not in the C group. 2. The pattern of impairment of respiratory function was the same (predominantly restrictive) in the CA and A groups. Moderately impaired respiratory function (predominantly obstructive) was found in the C group. The changes were more severe in the A group. 3. Irregular shadows were found in all three groups. Their incidence w;w* similar in the CA and A groups (re spectively two thirds and three quar Fig 1.--Incidence of the various types of roentgenographic shadows (1968 "e xte nd ed" ILO classification). Cases showing only a minimal degree of profusion of the shadows (grade 0 /1 ) are omitted except in the case of the group with associated irregular and rounded shadows. Table 4.-- Incidence of the Various Types of Roentgenographic Shadows* Group CA C A Irregular Shadows r Type s Type t 55 11 28 5 53 22 * 1968 'extended" ILO classification. Rounded Shadows Type p 6 11 1 Type q 4 7 2 Table 5.-- Profusion of the Various Types of Roentgenographic Shadows Irregular Shadows Rounded Shadows Group CA C A Type s L* M H ' 20 38 6 18 19 4 18 27 16 Type t ' L M H' 4 8 2 14 0 0 9 13 Type p 'L M H 430 10 9 0 0 10 Type q ' L M TT 5 10 232 1 0 * L, low; M. medium; and H, high (1968 "extended" ILO classification). Table 6.-- Extension of the Various Types of Roentgenographic Shadows Croup CA C A Irregular Shadows Type s Type t 'S* M G' 23 32 9 16 22 3 24 21 16 ' S M G' 2 9 3 1 4 0 1 8 13 Rounded Shadows f Typo p Type q S M G' ' S M "P 33 1 3 14 2 0 10 15 14 1 020 * S, small; M, medium; and G. oreat (19G8 "extended" 110 classification). ters of the cases) but much lower in th e C group (one third of the cases). Quantitative diirerences were ob served between the A and CA groups. The most advanced pictures and the highest degrees of profusion were found in the A group as compared with the CA group. Advanced roent- 274 Arch Environ H ealth/Vol 30, June 1975 Pneum oconioses/Scansetn et a! such. It occurs after a longer expo sure," but is common and has a similar morphological and functional picture. This was also suggested by Calamari et al," who also carried out their in vestigations in the Casale area. The findings of Vigliani," indicating that the CA industry is responsible for the majority of cases of asbestosis diag nosed in Italy during the recent past, can l)c explained by the fact that in our country the CA industry also in cludes large factories (employing more than 1,000 to 2,000 workers), : fact that does not apply to other as bestos industries (mining, textile, brake and friction material). Fig 2.--Incidence of roentgenographically demonstrable pleural changes. genographic features were very un common in the C group, in which high degrees of profusion were never ob served. 4. Involvement of the pleurae was found both in the CA group and in the A group. These were the only groups in which cases with pleural friction rub were found. Obliteration of the costophrenic angle without cal cification was more common in the CA group than in the A group, whereas pleural calcifications were more common in the A group, al though the difference between the two groups was not very great. These findings indicate a similarity between CA and A pneumoconiosis, although certain minor differences can also be distinguished. Symptoms of bronchitis were more severe in the CA group than in the A or C groups. A "synergistic" action of the two dusts or. perhaps, the microclimatic environmental conditions may be in volved here. Rounded shadows unassociated with irregular shadows were not found in the A group, but were found in the CA group and, especially, in the C group. The incidence of rounded shadows associated with irregular shadows in the CA group was about half of that found in the C group but was very low (,'!'r of the eases) in the A group. These findings bring to mind the recently proposed classification of CA pneumoconiosis as asbestosis, as besto-silicosis, or even simple sili cosis'- '' (definable as such from the clinical-roentgenographic findings): when the functional pattern observed in patients with predominantly or ex clusively rounded or irregular shad ows was examined separately it was found that subjects with irregular shadows showed mainly a reduction of the VC, total lung capacity, and pulmonary diffusing capacity for car bon monoxide, single breath and those with rounded shadows showed an increase of the residual volume whereas the FEV, ,, did not differ sig nificantly between the two groups." " The results of functional tests in our patients gave similar results. Our results point to the conclusion that the incidence of CA pneumoconiosis is high in the circumstance of a long du ration of exposure (average 20 years in our series). This suggests that the figures reported by other investiga tors are too low. However, Bohlig1 stressed the great mobility of work ers in this type of industry in West Germany. This does not apply to the Casale area in which our investiga tions were carried out, as proved by the high mean duration of exposure in our eases. From almost every standpoint CA pneumoconiosis is similar to classical asbestosis and can be diagnosed as References 1. Lindell K: What are the main uses of as bestos? transcript of the 2" Antiqua Conference on the Biological Effects of Asbestos, Quebec As bestos Mining Association, Jan 5, 1967. 2. Speil S, Leineweber JP: Asbrnto? M immi? in Modern Technology Johns-Manville Research and Engineering Center, 1968. 3. Nordmann M, Sonnenberg H: Asbcstzementstaub lunge. Arch Gewerbepathol 18 2U219, 1960. 4. Klosterkotter W: Zur Staubgcfahrdung bei der Herstellung und Verarbeitung von Asbest Zement-Material ArbcitsmrJ 1:119, 1963. 5. Bohlig H: Gesundheitsgefahrdung dureii Asbestzement Zcntralbl Arbeitsmed 20 201-211. 1970. 6. Einbrodt HJ, Hentschel D: Tc're\i>erimo:itelle Untersuchungen mit Arbeitsplatz*'aube" aus einem Huttonzemontwerk. Arch Gi werbt tu thol 22 354-366, 1966. 7. DeRosa R, Eliseo V, Lordi B: Sulla morbi lit degli operai di tino stabilimento per la lavorazione di manufatti di cemento-amianto. Folia Med 47:463-481, 196-1 8. Calamari E, Brasaseli P, Prigione L, et a' Aspetti radiologici e patogonetici dell'asbcstosi. Incidenza in Provincia ili Alessandria lite l \ .1 (V'.-l 18.399-113. 1968 9. Rubino GK, Seansctti G' Studi epidemio logici sull'asliestosi nell'industria inamifatturiera. Mtd La e 63.282-298, 1972. 10. Banerji DP: Asbestosis in an asbesto-co ment factory. Indian J hui Mt d 11-1.V7-166, l'.nl.s. 11. El Sewefy AZ: Radiologic findings in a ce ment-asbestos pipe factory, ./ Fyvpl Mal .-Is*'*' 52.836-8-14, 1969. 12. Solt E: Beobachtungen zur Asbestose in der Asbest-zement Industrie. Ztiitmlbl .4rbeitsmed 20.211-218, 1970. 13. Enterline P, Weill H: Aslvcstosis in a -- liestos eement workers. Preliminari repnrl \ o 28. Read before the International Conleremv on Biologleal Effects of Asbestos. Lion. October 1972. 14. Weill H. Waggenspaek C, Ro-utcr O, et ,d Radiographic and physiologic pattern- among workers engaged in manufacture of a-!u .-to- ement products. J (hi'in Mu1 !5 2ls-'253, 197.1 15. Vigliani EG A-be-to- cepo-cre and i'--e sulls in Italy, 111 S!i..e i l l on on lo-is /'/. <i f < y - I l ` ' ' e i fi ri net t Joluinni J ...... I'o.u I tg. b e e , <KI University Pi ess, 1951. pp IsO-l-e Arch Environ Health, Voi 30, Juno 1075 Pneum oconioses-Ur.in;,etti el ,d 2 /