Document gDZ0GNmQg0gV68zYvLZ7YMxGG

FILE NAME: Asbestos in India (IND) DATE: 0000 DOC#: IND006 DOCUMENT DESCRIPTION: Book Excerpt - Environmental/Medical Surveillance in the Asbestos Textile Industry Figures in parenthesis indicate number of workers. " v t a c t ENVIRONMENTAL-CUM- MEDICAL SURVEILLANCE IN THE ASBESTOS TEXTILE INDUSTRY There are tw o main uses of asbestos, one as a fibrous reinforce ment of papers, boards ,pipes or sheets by wet process, and the other in the textile industry which is basically a dry process. Thus, the workers working m asbestos textile industry are exposed more to asbestos dust as compared to the workers working in the asbestos cement sheets and pipes manufacturing industry. Hence, the study was taken up, to assess and evaluate the health hazards due to asbestos in a medium scale asbestosJextile industry at Ahmedabad. The different Processes in the Industry The asbestos fibres are initially crushed to small size on a grinding machine. Here the workers are exposed at the time of unpacking as well as grinding of the fibres. Afterwards cotton is thoroughly mixed with asbestos on a mixing machine. Then such material is spinned on a carding machine to manufacture asbestos cotton threads. Such prepared threads are woven on intersieving machine for manufacturing the yarns. After weaving such yarns with each other, ropes are prepared. The black ropes are prepared by applying the paste of graphite and other material. All these processes are dry, involving heavy exposure to cotton and asbestos dusts at all levels. This factory is also manufact uring asbestos mill boards. Here the process is wet and very few workers are involved. This process is more or less similar to the process of manufacturing asbestos cement sheets. Environmental evaluation of the factory and medical examination of the workers were carried out in this study. 71 MATERIALS AND METHODS Environmental Study : General information and data pertaining to hygienic conditions were collected by using standard questionary. The main problem was of dust fibres and dustiness. There were no problems related to heat, noise and illumination, and were not studied. The environmental study was then taken up in yarn and rope di visions of the factory. The yarn division was inside the factory, and the workers were exposed at the point of unpacking, mixing, spinning and weaving of asbestos and cotton to manufacture yarns. The rope divisi on was inside the compound, but outside the factory itself. Dust and fibre samplings for determining the atmospheric conce ntration of dust and fibre were carried out using standard sampling and and analysis techniques as described earlier (Ann. Rept., 1979d). Evalua tion of dust and fibre concentration and sizing were made according to standard methods (Ayer et al, 1965). The values of dust and fibre concentrations at the various places of this factory are given in Table33. It can be seen from the table that the concentrations of total and respirable dust were found variable in the yarn division, being higher at the point of unpacking and comparatively less at the weaving place. The mean values of the fibre concentration were higher at all the sampling points in this division than TLV recommended by American Conference o f Government Industrial Hygienists (ACGIH, U.S.A., 1964) and British Occupational Hygiene Society (BOHS., U.K., 1968). In the rope division which was outside the factory, the concentr ations of total and respirable dust were less than in yarn division. Here also the mean values of asbestos fibres were less than in yarn division, but much higher than TLV recommended by ACGIH, USA (1964) and BOHS., U.K. (1968). The high concentration of asbestos and other dusts can be due to dry process and there was no proper machinery which can trap the dust and fibres from the work environment. In earlier studies (Ann.Rept, 72 1976b; 1979d) in the asbestos cement factories, it has been found that asbestos and other dust concentrations were less than in this factory. Medical Surveillance : As this factory is existing since last six years only, the workers were exposed to less duration, but to higher concentration as mentioned above. This factory is registered under E.S.I. and Factory Acts. The housekeeping, dustiness, type of structure and sanitory conditions were very poor. Few of the workers were provided extremely small rooms to stay inside the factory compound and these workers are exposed for more or less for the whole day. There was no ventilation, natural or artificial, in these rooms. The ceiling o f these rooms were covered with asbestos cement sheets. In yarn division labour contract system was existing and payment was made on the basis of production. A total of seventy workers were working in this factory. Out of these, four were having pulmonary tuberculosis and one was uncoope rative. So, sixtyfive workers were studied. Detailed medical examination, pulmonany function tests. X-ray o f chest and sputum examination, were carried out of all workers. Thirty control subjects of more or less same age and socio-economic status were studied similarly. RESULTS AND DISCUSSION Table-34 shows age-wise distribution of exposed and control subjects. It is seen from this table that 63% of the total workers were below 25 years. TABLE-34 Agewise Distribution of the Exposed and Control Workers Age Group (Years) Below 20 21-25 26-35 36-45 Above 45 Total Exposed Workers 13 (20.0) 28 (43.0) 13 (20.0) 7 (10.8) 4 (6.2) 65 Figures in parenthesis indicate percentages. Control Workers 6 (20.0) 12 (40.0) 7 (23.3) 3 (10.0) 2 (6. 6) 30 74 workers!8' 35 9iVeS ' h9 PhVSiCa' char3ctsristi" control and exposed It is seen from Table-36 that 60% of total workers were working in the y rn division. where the dust concentration was maximum and 21 6% T " ? ? " T m r P8 di',isi0n where ,he dusI concentration was comparatively less due to the open environment. It is also seen that 78 4/ of the total workers were exposed fo, a maximum period o f three years! TABLE-35 Physical Characteristics of Control and Exposed Workers Age (Years) Height (cm) Weight (kg) BSA (m2) - Fi9ures in parenthesis Control (30) Exposed (65) (Mean S.E.M.) 27.27 1.57 161.27 0.61 45.47 0 .7 2 1.45 0.01 27.75 1 2 160.72 0 65 45.66 0.79 1.42 0.19 indicate the number of subjects. TABLE-36 Distribution of Workers According to Department and D uration o f Exposure Duration of Exposure (Years) Yarn Rope Department M ill board <1 1-3 4-5 >5 Total 7 26 4 2 39 (60) 6 7 1 14 (21.5) 1 4 5 (7.7) Figures in parenthesis indicate percentages. Mix Total 1 3 1 2 7 (10.8) 14 (21.5) 37 (56.9) 6 (9.2) 8 (12.3) 65 Table-37 shows the prevalence of respiratory symptoms as repor ted by the workers. It is seen that 30 workers (46.1%) were having respiratory complaints of chronic nature in one or the other form, while the control subjects were not having any significant respiratory symp toms of chronic nature. Amongst the respiratory symptoms, chronic TABLE-37 Respiratory Symptoms as Reported by The Exposed Workers Symptoms No.of Workers Chronic cough Dyspnoea Cough with expectoration Cough with expectoration and Cough, pain in chest and dysponea Cough and dyspnoea dyspnoea 8 (12.3)* 5 (7.7) 9 (13.8)* 3 (4.6) 2 (3.1) Total 30 (46.1) * P < 0.05 compared to controls. Figures in parenthesis indicate parcentages. No significant respiratory symptoms of chronic nature were present in the control workers. cough and chronic cough w ith expectoration were present in significant number of workers. In earlier studies in asbestos cement factories (Ann. Rept; 1976b; 1979d) respiratory symptoms were present in 21.4% and 19.4% subjects, respectively. In this factory, the workers were young and duration of exposure was less. So, the higher prevalence of respiratory symptoms may be due to high level of asbestos and other dusts in the factory. Banerjee (1968) reported in his study of fiftyone cases that 41% were having dyspnoea and 31% were having cough with expectoration. 76 as repor e having 'm, while ry sympchronic rs gnificant as (Ann. A% and >ung and spiratory dusts in e cases gh with Table-38 (A) shows the findings of general examination. The clu bbing which has been considered as late and inconsistant feature, was present in 9 (13.8%) subjects, while Banerajee (1968) reported in 7% TABLE-38 Findings on Clinical Examination of Exposed Workers (A) Main findings on general examination : Findings Clubbing Anaemia Cheilosis Glossitis Skin disease No.of Workers 9 (13.8) 11 (16.8) 4 (6.2) 3 (4.6) 3 (4.6) i Main findings of respiratory system examination : Fine/Coarse crepitation Bronchial breathing 18 (27.6)** 1 (1 .5) Rhonch'i 2 (3.5) ** P<0.01 compared to controls. Figures in parenthesis indicate percentages. No major clinical findings were present in control workers. of the total subjects studied. It is also seen from the table that 11 (16.8%) were anaemic, 4 (6.2%) were having cheilosis and 3 (4 6%) were having glossitis. All these findings can be due to poor nutritional status. The presence of fine or coarse crepitations has been considered as one of the important findings in the workers exposed to asbestos dust and was present in significant number of workers. Eighteen out of 65 (27.9%) had creptiations (Table-38. B). In the two previous studies in asbestos cement factories (Ann. Rept., 1976b -1979d) crepit ations were found in 3% and 14.2% subjects respectively. Banerjee (1968) reported crepitations in 19% of the total subjects with a dur -a a tio n of exposure for more than 5 years. In this factory more subjects 77 having crepitations with less duration of exposure, can be due to tlx gh levels of asbestos exposure due to the prevailing dry process. in UY " T T a'K(,966) f Und baSa' Crepi'ationS in ' and clubbinc L nn W ' ka'S- Wallac and Langlands (1971) compa^ insutoto,snihad0 bas^,h 5 0 . COmrOlS and ,ound ' h ig h e r proportion of expectoration. M u r p h y ^ " Z ' X t I brea, hl ess" * and . , . . . . P y et at (1971) reported basal crepitations in 14 9/ and Jubbm g m 19.8% of the 101 exposed pipe workers Berry reported the, ,6 ou, of 290 subjects had basa" crepitahons ' ' uPuiminenmaelan Z(1Z96Is8)T lthhaZt hthe agreacinoSrd' inCganCoafr c<rUeIpCitCat>ions nnPoartyr recimportant findings in morbidity studies of asbestos diseases They have also -- r r , ar , r h creoita,i na- cau h- heln in a ' ubbln9' smoking and occupational history can e, y % O H s T L a: T aCt COnclusion- BriIish Occupational Hygiene Soci- suggesting " cr asbestosis had nesz basal JZsZT 0 d s Z a iriun3crepita,ions as lung cUitattons thaf ZP7'ZTMd,drnh' T ,adl09,aphic can9es- So. i, can be concluded TMwould b; eZof gZ.eatZdiaganSoasl tiCc rev0ai'lua,eiOfnoSr ienvaWluartkienrgS th<"e>e8x8pdos>uressbriesks.tos T A B L E -39 A Comparison of P.F.T. in Control and Exposed Workers Control (30) Exposed (65) VC (lit) FEVi.0% *FE*F* 200-1200 ml (lit/sec) FEF25-75% (lit/sec) ** P<n m 3.47 0 .0 9 80.88 1 .1 3 4.51 0.31 3.01 0 .1 8 2.86 0 .0 8 ** 82.11 1.26 4.50 0 .2 5 2.92 0 .1 7 Figures in parenthesis indicate the number of workers. 78 *7 - . V - W lue to the process. d clubbing 1) compajportion of sness and ; in 14.9% "y (1971) party recne of the y have also >n, dyspnstory can iene Socione of the ' changes with basal concluded 3 asbestos Jre risk. (65) L0T .26 3.25 0.17 ft A comparison of pulmonary function tests in Table-39 indicates hiohlv F v a r 2 T ,h ' Vf? in ~ workers- w i' h cLU n. l ,3teS' su99est'n9 the presence of resin- ctive type of lung disease m exposed workers. Busser et al (19711 reported rn their study of asbestos textile and asbestos spraying wo, t Z progress,ve decrease of vital capacity. The studies carried out Ly Banerjee (1968). Weil, et a, (1973) indicate a loss in VC of the workers exposed to asbestos. Harries (1973) and Becklake et al (1972) found definite relatronshrp between the exposure to asbestos and the decrease m vital capacity. When the pulmonary function tests were compared bo h ' ", 9 habl' S' nlV VC W3S Seen -sn ifica n tiy reduced in both non-smokers and smokers of the exposed group (Table-40). TABLE 40 Comparison of PFT According to Smoking Habits in Control and Exposed Workers VC (lit) FEVi.0% FEF200-1200 nil (lit/sec) f e f 25_ 75% (Lit/sec) Non-Smoker Smoker Control (20) Exposed (32) Control (10) Exposed (33) (Mean =fcS.E,M.) (Mean S.E.M.) 3.46 0 .1 2 81.73 1 .4 5 4.87 0.36 2.70 0 .1 0 83.00 2.04 4.69 0.35 * 3.49 0 .1 3 79.15 1 .7 3 3.77 0.51 3.02 0.11* 81.26 1.45 4.26 0.38 3.03 0 .2 5 3.18 0.28 2.99 0.22 2.68 0.20 *P <0.05 ; ** P <0.01 compared to Figures in parenthesis indicate the ni Other functional parameters were not much affected. Since smoking causes loss o f ventilatory function, the significant loss of VC in smokers can be attributed to the synergestic affect of asbestos dust and smoking habrts. whereas in non-smokers, the loss of VC can be interpreted due to the effect of dust alone. Wallac and Langlands (1971) in their study of the asbestos exposed workers reported a considerable impairment of 79 lung function, i.e.. vital capacity, and the authois concluded that smo king and exposure, of asbestos have additive effects in causing impaindent of lung function. But the present results indicate that in non-smokers there was more loss o f vital capacity than in smokers. McDonald et ai k fe n /lh ,ha' " r VC a" d FEV- "/- <> -- ease to similar be a lc m d p 9 7 ' eXP SUre' but in smokers ^ w ill only th. J r ?d' , PreSem 65 (Ann' Repl - 19 7 6b : 1979d) have also shown effect of smoking on lung function. seen?ha,e B 1, g h, v 7 ,b0/ adio,o8ical ,indi" ^ Bbsed workers. It is ' ^ tota* subjects were having small regular or TABLE-41 Findings of Chest X-rays in Exposed Workers Radiological Abnormalities Regular opacities Irregular opacities Regular and irregular opacities Total No. of Workers 3 (4.6) 1 (1.5) 2 (3.1) 6 (9.2) Figures in parenthesis indicate percentages. irregular opacities either separately or combined The small regular opac ities suggest the past exposure to some mineral dust or silica. It is interesting to note that all the six subjects were having cough with expectoration, five were exposed to less than five years and all were from yarn division and smokers. On clinical examination they all had crepitations. On sputum examination 10 subjects showed asbestos bodies which merely suggest the past exposure to asbestos. Banerjee (1968) reported m 16 out of 19 sputum examinations, the presence of asbestos bodies 80 SUMMARY (1) Total and respirable dust and asbestos fibre concentrations in the work environment were found much higher than TLV in this factory. (2) The affected working population was young and was exposed to high levels of asbestos dust. The working and living conditions of these workers were very poor. (3) Nearly half of the working population was having respiratory sym ptoms in one form or another and more than one-fourth were having crepitations. (4) The signs of nutritional deficiency were present in many subjects. (5) The reduction in VC in exposed workers suggests the presence of restrictive type of lung disorders. (6) The reduction in VC was irrespective of smoking habits, but was found more in non-smokers than smokers. (7) Nine percent of the workers were having small regular or irregular opacities in chest X-rays. (8) Fifteen percent of the total subjects showed the presence of asbe stos bodies in sputum. 81