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FILE NAME Brakes BRK DATE 1999 DOC BRK156 DOCUMENT DESCRIPTION Journal Article - Asbestosis and Small Cell Lung Cancer in a Clutch Refabricator 602 Downloaded from on 20 March 2006 Occup Environ Med 602-605 Asbestosis and small cell lung cancer in a clutch refabricator Jeffrey L Levin Michael F O'Sullivan CarolynJCorn M Glenn Williams Ronald F Dodson Department of Occupational Health Sciences JL Levin Department of Cell Biology and Environmental Sciences University of Texas Health Center Tyler TX USA MF MF O'Sullivan CJ Corn MG MG Williams RF RF Dodson Correspondence to Dr Jeffrey L. Levin The University of Texas Health Center 11937 US Highway 271 Tyler Texas 75708-3154 USA Telephone 001 903 877 5900 fax 001 903 877 7982 email levin@uthct.edu Accepted 17 May 1999 Abstract confirmed measurable increases in asbestos Objectives present a case of asbesto- due to frequent braking. sis and small cell lung cancer caused by Rodelsperger et al measured asbestos fibre asbestos in a clutch refabricator concentrations in the air during brake repair Methods surfaces of used Analysis by scanning electron microscopy clutches similar to those refabricated in showed concentrations of chrysotile fibres which the worker's workplace were rinsed and were considerably higher than measurements by the filtrate analysed by analytical trans- light microscopy Rood and Scott analysed mission electron microscopy Tissue sam- airborne chrysotile asbestos in a workplace ples were also analysed by this technique making clutches and brake shoes.Their obser- Numerous chrysotile fibres of vations by transmission electron microscopy respirable dimensions and su cient length to form ferruginous bodies FBs were detected from rinsed filtrates of the indicated that only between a fifth to a half of fibres longer than 5 mwould have been visible by optical microscopy and in their samples all clutch Bronchoalveolar lavage fluid con- fibres were of respirable dimensions tained many FBs characteristic of asbes- Publications on the potential for exposure to tos bodies Necropsy lung tissue showed grade 4 asbestosis and a small cell carcinoma in the right pulmonary hilum Tissue analysis by light and analytical electron microscopy showed tissue bur- dens of coated and uncoated asbestos asbestos used in automotive friction products is therefore limited to data from sampling in areas of manufacturing processes or in areas adjacent to repetitious braking There are few data available on exposures after use or during refabrication particularly when this process fibres greatly exceeding reported environ- involves clutch components mental concentrations 3810 FBs dry In the present report material easily freed weight and 2 080 000 structures 0.5 m from worn clutches such as those used in the dry weight respectively % of the cores workplace in question were analysed The were identified as chrysotile worker's illness attributed to exposure to Conclusions refabrication may asbestos from refabricating clutches is dis- lead to exposure to asbestos of su cient magnitude to cause asbestosis and lung cussed with ultrastructural analysis of lung tis- sue and clutch surface extracts cancer Occup Environ Med 602-605 Keywords chrysotile asbestos ferruginous bodies electron microscopy lung cancer asbestosis The use of asbestos as a friction product in vehicles constitutes only a fraction of the total consumption of asbestos containing materials used in our society Although no one would argue its historically important role in vehicle safety the recognition that exposure to asbestos carries a risk of disease has prompted ques- tions as to fibre emissions from such sources Clinical case history A 59 year old man was admitted to hospital with a 1 month history of persistent cough and progressive dyspnoea A chest radiograph on admission showed focal consolidation in the right upper lobe a coarse diffuse interstitial pattern most notable at the bases and bilateral apical pleural scarring The patient had smoked one to one and a half packs of cigarettes a day for 35-40 years The most notable element of his occupational history was work as a clutch rebuilder and sorter from 1966 to 1990. He drilled rivets from clutches to Attention to such emissions has primarily focused on release during vehicle operations with most of these studies focusing on brake emissions Jacko et al concluded that 99.7 of the emitted asbestos was converted to olivine or forsterite particles Williams and Muhlbaier used an enclosed brake testing machine to test emissions from automobile brakes.They concluded that although asbestos in such friction products constituted a minor fraction of ambi- ent asbestos concentrations there may be noticeable increases in asbestos concentrations near high braking areas such as tollbooths The work of Jaffrey in such real life environments remove the used facings from the plates He lived on a small rural farm Physical examination showed coarse rales Pulmonary function studies showed markedly reduced lung volumes and diffusion capacity accompanied by obstruction Skin testing and sputum analysis were negative for evidence of tuberculosis Fibreoptic bronchoscopy produced washings with many ferruginous bodies FBs consistent with asbestos bodies Transbronchial biopsy of the right upper lobe showed alveolar septal fibrous thickening and an alveolar inflammatory cell infiltrate including macrophages some multinucleate and of Downloaded from Asbestosis and small cell lung cancer in a clutch refabricator on 20 March 2006 603 giant cell proportions and eosinophils No acid fast bacilli or fungi were detected No well defined granulomata or classic viral inclusions were found The patient was diagnosed with eosinophilic pneumonitis and asbestosis and responded to initial treatment of his eosinophilic infiltrate with bronchodilators and high dose corticosteroids After discharge however he became gradually more dyspneic with weight loss He was readmitted with severe hypoxaemia Clubbing was noted and a chest radiograph showed right hilar enlargement Computerised tomog- raphy CT of the chest showed a large right hilar mass and confirmed severe interstitial fibrosis A CT guided biopsy of the mass showed a small cell undifferentiated carci- noma The procedure was complicated by a pneumothorax Despite chest tube placement and initiation of chemotherapy the patient died of respiratory failure Necropsy findings of the respiratory system showed a severe bilateral interstitial pulmo- nary fibrosis with asbestos bodies and with honeycombing most pronounced beneath the pleural surfaces and at the bases grade 4 asbestosis b undifferentiated small cell carcinoma at the right lung hilum with intrapinutrapulmonary lmonary intrapulmonary right diaphragmatic and mediastinal lymph node metastasis Formalin fixed lung tissue was sampled at random sites and analysed by light and electron microscopy sample was gently swirled after which half of the volume was filtered through a 25 mm diameter polycarbonate Nucleopore filter with a pore size of 0.2 ...mThe filter surface and the surface particulates were coated with evaporated carbon and the filter matrix was dissolved with chloroform The carbon replicas were examined at magnifications of up to 50 000x in a JOEL 100CX analytical transmission electron microscope ATEM equipped with an EDAX NX x ray energy analyser ANALYSIS OF TISSUE Formalin fixed lung tissue was analysed for particulate burden Lung tissue was processed embedded in paraffin and haematoxylin and eosin stained sections were evaluated by light microscopy Additional lung tissue was dissected pooled and prepared for particulate analysis by a digestion procedure developed in our laboratory Samples of the pooled digest were filtered through mixed cellulose ester filters Millipore for light microscopy assessment for the presence of FBs A quarter wedge of each filter was screened at x200-400 magnification with an AO microstar microscope Aliquots of the pooled sample were evenly distributed on a 0.2 ...mpore size polycarbonate filter Nucleopore filtered and carbon repli- cas were made The area scanned in each replica was assessed at x20 000 for fibres 0.5 m An additional scan at x600-1200 was carried out to locate FBs which were analysed for core composition Methods ANALYSIS OF CLUTCH MATERIAL Clutches similar to those that had been refabricated in the worker's workplace were analysed for friable or loose material as might be expected to become airborne in the workplace Exposed surfaces were rinsed with 100 ...l prefiltered water and this washing was collected in a sample vial Six such clutch pads were sampled in a similar manner Each rinse aliquot was increased to about 10 ml The mr material Figure 1 A clump of face shows thepresence complex structures Bar m collected collected gentle bundles chrysotile washing of the surface of the used clutch as well as very long chrysotile Results CLUTCH ANALYSIS Numerous bundles and separated fibres of chrysotile asbestos were seen on ATEM fig ) Confirmation of fibre identity as chrysotile was done by energy dispersive x ray analysis fig 2 and selected area diffraction The samples contained numerous respirable sized chrysotile fibres including many which were of sufficient length 8...mto form FBs if inhaled TISSUE ANALYSIS Ferruginous bodies consistent with asbestos bodies were found in regions of fibrosis and inflammation fulfilling pathological criteria for asbestosis The number of isolated FBs consistent with asbestos bodies were counted by light microscopy as being 3810 FBs dry weight This concentration clearly exceeds those found in people with environmental exposures. ,, Light microscopy allows for FBs to be identified as asbestos bodies with a high level of accuracy However it is not possible by light microscopy to determine the type of asbestos core Electron microscopy was used for this purpose More than 72 of the cores of analysed FBs were chrysotile asbestos fig 3 Nine per cent of the ferruginous body cores were amosite and % were tremolite The remaining FBs were totally coated and therefore could not be analysed for core composi- tion The uncoated asbestos fibres were found as both bundles fig 4 and more isolated 604 Downloaded from on 20 March 2006 Levin O'Sullivan Corn et al 600 -500 chrysotile fibres At lower magnification scan which emphasised longer fibres there were 216 structures dry weight of lung Si 400 Mg LT = 400 Counts CuCu Counts 300 Counts Counts 200 F 100 F SMH 0.000 1.000 2.000 3.000 Li 4.000 5.000 Litt 6.000 7.000 Ly 8.000 i 9.000 10.000 Energy keV Figure 2 x ray energy dispersive analysis confirms clutch washingfibre identity as chrysotile Live time to acquire the spectrum om ef 100 -. Figure 3 The chrysotile core of this ferruginous body Fe from the worker in question can be identified by the protrudingfibril MgSi and its characteristic tubular structure . 4 Ps a ad + a ee - ad ed we 7 ~~ oe t ya ay - 2 # * 4 Figure A large cluster of long chrysotile fibres collectedfrom the worker's lung tissue When the higher magnification 20 000 was used the number of structures rose to 2 080 000 structures dry weight due to inclusion of shorter fibres 0. 5 ...m The only type of uncoated asbestos fibre found in the scanned area was chrysotile Uncoated chrysotile fibres were composed of short fibres /5...mas well as considerably longer fibres up to 44 ...mIt should also be recognised that in this unique exposure many of the longer inhaled chrysotile structures were within the cores of FBs which are only formed on fibres > ...min length Either of these measurements of tissue fibre burden exceed those expected to result from environmental exposure especially from the East Texas region where the man lived.,," Conclusions This case has many unique features The limited published data deal with exposure to asbestos from automotive friction components either in the initial manufacturing or in the use phases and these are mainly found on studies of brake components and not material associated 1-35 with clutches Few studies exist about exposure to friction products of asbestos during " maintenance or repair after use There are case reports of pleural mesothelioma diagnosed in a laundry owner handling washing machine clutches and in a brake repair worker In both cases the presence of chrysotile asbestos in the lung tissue was confirmed by electron microscopy and energy dispersive analysis The man in the present report was exposed to the components of clutches after use an area devoid of published data It is a valid observation that without air sam- pling there is no way to measure airborne exposures in the workplace As is the case with many exposures of the type which this particular worker sustained such monitoring information does not exist However based on the data in the present report chrysotile asbestos of respirable size was found in a friable condi- tion on the clutches analysed These types of materials from clutches were handled in the work environment in the refabrication process Furthermore the analysis of lung tissue showed the same types of fibres of the same dimensions as identified on the clutch components It seems reasonable therefore to extrapolate that the characteristics of the chrysotile fibre burden in tissue made up of many fibres 5 ...min length reflect a unique occupational exposure as chrysotile found in the tissue from environmentally exposed people both in our laboratory and in the scientific literature is predominantly made up of short fibres ( 5 ...min length The finding of a small percentage of amphibole fibres is not entirely unexpected in people with exposure to chrysotile from any source and in this case could also have arisen from other unidentified exposures None the less the chrysotile fibre burden certainly predominates in this case A documentation of the type of material used in the clutches chrysotile and of the presence of respirable potential of this fibrous portion was made through electron