Document 4QJ37J9gdEmEByXwbvQ6112Va

FILE NAME: Asbestos in India (IND) DATE: 1983 Apr DOC#: IND017 DOCUMENT DESCRIPTION: Journal Article - Pattern of Asbestos Workers Bombay INDIAN JOURNAL OF OCCUPATIONAL HEALTH, 1 9 8 3 (A p rn ); XXVI (4 ): 305-313. CAIO Code 6318 10 11 12 13 71 "PATTERN OF ASBESTOS WORKERS IN BOMBAY" * S. P. SHAH, S.R. KAMAT, & A. A. MAHASHUR** SUMMARY: ed VC and diffusing capacity may pre A study of 28 workers exposed to asbestos, and reporting to this unit is pre sented. They were thoroughly investi cede changes in the chest roentogenogram or are seen with equivocal radio logical changes. gated with radiographs,, lung function An over-all diagnosis of asbestosis is and arterial blocd gases at rest and based upon: physical signs of pulmo after exercise to detect established ca- nary fibrosis, radiological abnormali Jteavd in 15 (46%) workers). InS ties and restrictive changes in lung f g,es of asbestosis. Basal rales were-X functions. With slight modification of A>4 subjects there were obvious abnor standad criteria, 5-10 we used the fol malities cn radiographs suggestive of lowing evidence for the diagnosis of asbestosis. R.adiologically the small re- asbestosis : ticuloncdular opacities in lower and middle zones were commonly found. (1) Adequate history of exposure to In 5 workers there was evidence of asbestos fibre at work. obstruction but in most cases restric (2) Clinical presentation of breath tive functional defect was seen. Arte lessness, cough, clubbing and fine rial oxygen desaturation on exercise rales on ausculation. cccured in 8 (35%) workers. (3) Radiological evidence of pleural INTRODUCTION: plaques, calcification or reticulo- nodular shadows suggestive of in Alongwith wider use in industries, terstitial fibrosis. world consumption of asbestos is es (4) Restrictive functional disability and calating; so also the awareness of health arterial blood gases alteration at hazards due to asbestos exposure has come significant in past' 30 years. Tho rest or on exercise testing. ugh a typical advanced asbestosis is We could not use D eo as a test due diagnosed without difficulty, on the to technical reasons as also lung basis of clinical findings, radiological biopsy 11 as unnecessary for confirm abnormalities and restrictive charges in ing the diagnosis of asbestosis. De pulmonary function, but the industrial monstration of asbestos bodies in spu physician should be concerned with tum was also not included in criteria diagnosing, an early asbestosis. Leath- as it does not usually prove asbesto n>t 1 has suggested that the earliest sis 10.12 sfienndciengofinbasaaslbecsrteopsiistatmioanys. bWe htihlee opthreer MATERIAL & METHODS: workers 2-4 have found that abnormali From suspected exposed workers, ties in lung function particularly reduc 28 were studied fully to evaluate for `""Presented during 31st Annual Convention March '83. Work sponsored by Kilachand Research Endowment IAOH Bombay Branch. ` Dcpaiment of Chest Medicine Seth G. S. Medical College & K.E.M. Ucsp;tal, Parcl. Bombav-^-00 012. 305 306 INDIAN JOURNAL OF OCCUPATIONAL HEALTH abnormalities associated with asbestosis. They had been working in diffe rent factories in the city. The inves tigations consisted of full radiograph, clinical examination, lung function and blood gas studies. Chest examination, particularly included looking for fine basal rales and presence of finger clubbing. Spirometry was done on Stead-Well's spirometer before and after a bronchodilator aerosol. All lung functions have been expressed as per centage of predicted values as per In dian norms.13 As per standard crite ria normal functions were within 20% of predicted values, mild disabi lity between 60-80% moderate bet ween 40-50% and severe disability less than 40%. In all subjects blood gas studies before and after exercise (as an alternative to Deo studies) was done on the same day. RESULTS: All 28 workers were males with a mean age of 36 years (Table No. 1). Table 1 : Age Distribution exposed workers. ' Age in Years 21-30 31-40 41-50 51-60 Mean Age : 46 Years. of asbestos 4 (14%) 17 (63%) 6 (20%) 1( 3%) Of these 20 (71%) were smokers, in cluding 3 heavy (2Q+/day) smokers. These belonged to different depart ments like winding, spinning, polish ing etc. with a mean exposure to as bestos fibre of 12.9 years. Of thes< 20 (72%) had been exposed for over 10 years. While mean latent period before any clinical symptoms was 11.9 years but 6 (20%) manifested after an exposure of over 15 years. (Table 2). Table 2: Duration of exposure to asbestos and time lag before development of symptoms. Yrs. of exposure No. of patients Period No. of patients 1-5 6-10 11-15 16-20 1 (3%) 7 (25%) ! 14 (47%) 7 (25%) Mean - 12.9 years Breathlessness on exertion was a prominant symptom in 26 workers (93%). Dull aching chest pain and feeling of tightness in chest was commoner in workers with pleural or advanced pulmonary involvement. Unusually 22 (79 %) workers also complained of anorexia, weakness and weight loss (Table No. 3). 1-5 6-10 11-15 16-20 M ean-11.9 Years 5 (18%) 8 (29%) 9 (33%) 6 (20%) Table 3 : Clinical symptoms in 28 asbestos workers. 1. Breathlessness 2. Anorexia, Wt. Loss Weakness etc. 3. Chest pain 4. Cough 26(93%) 22(79%) 16(57%) 15(46%) Mean duration of symptoms 2.73 Yrs. PATTERN OF ASBESTOS WORKERS IN BOMBAY 307 Finger clubbing (gr. M I) was seen in 7 workers (25%). The presence of t'ine rales was common in subjects present where'in the radiograph show ed small reticulo-nodular deposits or honey combing. Radiological evidence suggesting asbestosis was seen in 24 patients (Table No. 4). Mainly there were bi lateral fine reticulo-nodular deposits in lower and mid zones (79%) (Fig. 1 & 2). Pleural involvement was seen in 15 (54%). It was more common on the lateral parietal layer than on dia phragmatic layer (Fig. 3). One worker presented with circular mass on left lateral wall in upper zone wiih pleural involvement on right side thought to be malignant. However this had not Table 4 : Radiological asbestos workers patterns in changed over 4 years as compared with earlier X-rays : later we aspirated pus by direct puncture from this mass Pleural involvement only 2 (7%) (Fig. 4). Parenchymal involvement only 9(32%)Low FEV 1 was seen in 5 workers Pleural & Parenchymal Normal Nonspecific " 13 (47%) 2 ( 7%) 2(7%) (17%); while VC% of predicted was abnormal in 15(53%) workers, sug gesting that restrictive ventilatory de fect is more easily judged by FVC Sm all `bead-like' and fine linear opacitiet in early asbestosis. Smalt nodular and linear opacities, mare in both lower zones than mid zone. Note the shaggy heart borders. Bilateral extensive pleural thickening with ralrifca'inn. PATTERN OF ASBES'I OS WORKERS IN BOMBAY 309 Cicular rounded opacity on left lateral wall. {Table No. 5). This was probably commensurate to the degree of pleural involvement (Table No. 6) 5 workers refused arterial blood gas study. Mean pO 2 at rest was 86 mm of Hg while mean paCOJ was 36.8 mm of Hg suggesting mild hyperventilation at rest. Mean SaO.j was 96% at rest while it decreased to 95% on exercise (Table No. 6). Significant arterial oxy gen desaturation on exercise cccured in 8(35%) workers. DISCUSSION : The study narrates our experience and may not reflect on the relative in cidence of asbestosis in Eombav. The hazards due to exposure of asbestosis were first recognised in Furopc 14 at the beginning of the 29th century. Murray reported the first case of pul monary asbestos is in 1907. In 1930, asbestosis was recognised as an indus trial disease and preventive measures were taken. It is reported 15that usually a delay of several decades occurs between first exposure and onset of symptoms and in no study in man, it has been possi ble to measure the dose. In our study mean lag period was 11.9 years. Though we have not assessed the role of smoking in our study, this has been established by others.16 Asbestos inhalation also produces pulmonary fibrosis. I7' ie While a high prevalence of fibrosis is seen in smoking asbestos workers but it is uncertain whether the two have an additive effect.18 Table 5 : Spirometrie indices in asbestos workers FEV 1 % -------- % FVC VC Obs. ,% VC Pred. Mean 40 60 740 1(3%) 4(14%) 4(14%) F E V , % - 86.27% FVC 80 Normal 7 60 4(14%) 23(83%) 7(25%) 13(47%) VCObs% 76.82% VC Pred. Table 6 : Summary of radiographic and functional changes. Sr. No. Radiology PFT O R P a 0 2 in mm of Hg Sa02 Rest Exer. On Exer. 1. ABJN (i) ABN (Mod) 76 -- 81 NC - 2. ABN (1) N ABN (Mod) 91 93 3. ABN (2) N N 106 -- 101 ABN (3) N ABN (Mild) 78 -- 94 'SY 4. 5. ABN (2) N N 102 -- 97 NC 6. ABN (2) N ABN (Mild) 100 -- 106 NC 7. ajsinuno; N N 84 112 t 8. ABN (2) N ABN (Mod) -- 9. N. N N 112 -- 111 NC 10. ABN (2) N ABN (Mild) 92 -- 95 NC 11. 12. ABN (3) ABN (3) N ABN (S) N ABN (Mild) 70 -- 51.5 81.5 -- 87 * 13. ABN (3) N ABN (Severe) 56 --- 60 14. ABN (3) N ABN (Severe) 102 .-- 62 15. ABN (3) N N 83 -- 88 \r 16. ABN (3) N ABN (Severe) 66 -- 43.5 17. ABN (2) N N 18. ABN (2) N N -- 99 -- 100 XInT/*C** 19. 20. ABN (3)ABN (Mild) N ABN3' N N -- 100 -- 97 MP 21. ABN (2) ABN (Mod)ABN (Mod) 64 -- 65 NC 22. ABN (2) ABN (Mild) N -- 23. ABN (3)ABN (Mild) N 76 -- 73 * 24. N N N -- 25. 26. ABN (3) ABN (3) N ABN (Mild) 71 N ABN (MM) 90 -- 83 * 81 27. ABN (3)ABN (Mod)ABN (Mild) 100 -- m 28. ABN (NS) N N 88 -- 98 O- Obstructive R-Restrictive NC-No change ABN Abnormal 1- Pleural involvement 2- Parenchymal involvement 3-Pleural + Parenchymal involvement N-Normal NS-Non-specific I S a O j -- + 0.5% jSaO -- L -- 0.5 % NC 0.5% y i PATTERN OF ASBESTOS WORKERS IN BOMBAY 311 There is high risk of developing lung cancer in asbestos workers who are smokers. In a study by Selikoff 19 the combination of asbestos exposure and cigarettes increased the risk 90 times as compared with control group. Re lative contribution of cigarelte smok ing to malignancy is not assessed in our study as the exposure period is short. Clinical features of asbestosis are not pathognomonic. Breathlessness on exertion was the predominant symptom in our study. Breathlessness is seen first after heavy work and then with smaller exertion as the disease pro gresses. As reported by Parkes18, the degree of breathlessness does not correlate well with abnormal physical signs in the lung and radiographic ap pearances. Other surprising feature was presence of generalised symptoms like anorexia, weight loss and weak ness in 22 workers (79%). This per haps related to chronic tiredness and mild dyspnoea. In majority of cases only a small quantity of sputum was complained. Chest tightness was com mon in patient with advanced disease probably due to stiffness of lung while chest pain was present with involve ment of pleura. Fine crepitations are the earliest and most constant physical sign as re ported earlier.7- 20They were first de tected either at the bases after a deep inspiration. As thd fibrosis progress they become more numerous and widespread. An important feature of this is that they are persistent and not altered by coughing, as is often with other lung diseases. The difficulties in the diagnosis of early radiological changes of asbes tosis has been emphasized repeatedly by Pendergras since 1978. so it is not surprising to find a difference of opi nion in radiological diagnosis. Radio graphic abnormalities like bilateral small irregular linear opacities pre dominant in the lower lung fields, are suggestive of interestitial fibrosis22-23 The early bilateral changes are first seen in costophrenic angles in different forms of increased basal vascular mar kings; these may be thickened particu larly at branchings with small rounded bead like opacities along the path of finer markingsj and a horizontal pattern resembling kerley's B lines. 2324 In more advanced cases a honey combing pattern is common either due to fibrosis or superimposition effect of different radiodensities. When fibrosis is severe, the outlines of the diaphragm and heart shadow may become blurr ed and shaggy (Fig. 2). Rounded opa cities similar to silicosis are occa sionally seen probably due to free sili ca present in asbestos cement dust.25 But larger opacities resembling those of Caplan's syndrome and progressive massive fibrosis are unusual, with as bestosis. According to Yazicoglu et al,24the first obvious sign sign is the de velopment of geographic calcified pla ques in the pleura, radiographic chan ges of pulmonary fibrosis develop later. As suggested by Gibbs.27the chan ges in pulmonary mechanics were con sidered to be early because they occured in workers who had no radio logical evidence of disease or definite changes in other measurements of lung function. The characteristic abnorma lities reported include progressive re duction in VC, TLC and in diffusing capacity, increased static recoil pres sure, decreased lung compliance and decreased VC% predicted, without air ways obstruction. The restrictive lung lesion in asbestosis with decreased in spiratory capacity and decreased lung volume is probably caused both by pleural adhesion and plaques and bv shrinkage due to pulmonary fibrosis.28 312 INDIAN JOURNAL OF OCCUPATIONAL HEALTH Airways obstruction was not consi dered a feature of asbestosis.4 Though recent reports29 express the view that obstruction especially of small airways is not uncommon. It is widely known '*M that the main functional defect in asbestosis is reduced diffus ing capacity of the lungs, this was in ferred from occurence of arterial oxy gen desaturation especially after exer cises as in our study too. ACKNOWLEDGEMENTS: This study received financial sup port from Nandlal Kilachand endow ment under the auspices of Indian Association of Occupational Health for which we are extremely grateful and indebted to them. We also thank Dr. C. K. Deshpande, Dean for per mitting this study. Most subjects were seen through kind reference of Insur ance doctors particularly Dr. H. S. Bharati and Dr. P. K. Rane. In doing lung function help rendered by Smt. S. S. Athawale is acknowledged. REFERENCES: 5. Mcvittie J.C. (1965), Asbestos in Great Britain. Annals of the New York academy of science 132:128 138. ' 6. Berry G., Gilson J.C. et al (1979), Asbestosis a study of dose-res ponse relationship in an asbestos textile factory. Brit. Jr. of Indus trial Med. 36:98-112. 7. Murphy R.L.H., Gaensier S.A. (1978), Diagnosis of asbestosis - observation from a longitudinal survey of shipyard pipe coverers. The Am. Jr. of Med. 65:488-498. 8. Faysal M.H., Gerald Nash et al (1977) , The significance of as bestos exposure in the diagnosis of mesothelioma -- A 28 years exposure from a major urban hos pital Am. Rev. of Resp. Dis. i 15: 761-767. 9. Epler G.R., Carrington C.B. et al (1978) , Crackles (Rales) in the interstitial pulmonary disease Chest 73:333-339. 1. Leathart G.L. (1968), Pulmonary 10. Parkes R.W. (1977), Asbestos re function test in asbestos workers. lated disorders Brit. Jr. Dis. Trans. Soc. Occup. Med. 18` Chest 67:261-300. 49-53. 11. Scott J.K., Hunt R.C. (1975), The 2. Hans Weill, Morton M. et al (1975), Lung function consequ diagnosis of asbestosis. Brit. Jr Dis. Chest 69:51-56. ences of dust exposure in asbes. tos cement manufacturing plants. Archieyes of Environmental Heal h. . '30:88-97. 3: Becklake M.R., GJ McDonald et al (1970), Lung function in relation . to chest radiographic changes in Quebec asbestos workers. Bull. Physiol. Path. Resp. 6:637. 12. Becklake M.R. (1976), Asbestos related disease of the lung and other organs. Am. Rev. Resp. Dis. ' 114:187-227.. 13. S.R. Kamat, B.S. Sanna, C. Ven katraman et al (1977), Indian norms for pulmonary function ob served values prediction equation and intercorrelations. The Jr. of 4. William R.. Hugh-Jones P. (I960),' , . 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Ilcayto et al smoking, asbestosis and pulmo (1980), Pleural calcification, pleu nary fibrosis Am. Rev. Resp. Dis. ral mesothelioma and bronchial 104:223-227. cancers caused by tremolitc dust, 19. Selikoff I.J., Echyler et al (1968), Thorax 35:564-569. Asbestos exposure, smoking and 27. Gibbs G.W., Jodoin G. et al Neoplasia. The Jr. of Am. Med. (1971) , Early effect of asbestos Association 204:106-112. exposure in lung function 20. Nath A.R., Capel L.H. (1974), Am. Rev. Resp. Dis. 104:525 Crackles -- early and late, Tho 535. rax 29:223-227. 21. Chem et al (1973), Asbestos wor kers in Singapore. Arch. Environ. Health 26:290-293. 28. Brian E.H. and William R. (1961), Pathology of asbestosis with re ference to lung function Thorax 17:261-281. 22. Soutar C.A., Simon G.. Tumes Warwick M. et al (1974), The 29 Muldoon B.C., Warwick M.T. radiology of asbestos induced di (1972) , Lung function studies in sease of the lungs. Brit. Jr. of asbestos workers. Brit. 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