Document zQ2OGy8v3ZNoQ7D9JwvQ2OO77

FILE NAME Brakes BRK DATE 2014 DOC BRK225 DOCUMENT DESCRIPTION Journal Article - Asbestos Exposure Among Transmission Mechanics in Automotive Repair Shops he- Ann Occup Hyg 2014 2014 1-15 1-15 meu093 The Chartered Society or Worker Hearn Profection Asbestos Exposure among Transmission Mechanics in Automotive Repair Shops Natalia Salazar Mar^>aFernanda Garc^>aPatrick N. Breysseand Juan Pablo Bonilla,, Universidad de los Andes Bogot^Colombia 1.Department of Civil and Environmental Engineering Public Health Johns Hopkins University Baltimore MD USA Bloomberg School of 57-1-3324313 mail uniandes edu.co 2.Division of Environmental Health Engineering ext 2811 2810 fax be addressed Tel 57-1-3394949 * Author to whom correspondence should revised version accepted 9 October 2014 Submitted 21 March 2014 2014 revised 2 October 2014 ABSTRACT of industrial products including clutch discs of analyzed Asbestos has been used in a broad variety Objectives high income countries that have vehicles Studies conducted in these workers are exposed the transmission system of mechanics have concluded that personal asbestos exposures of transmission with the US Occupational Safety and Health Administration to asbestos concentrations in compliance of clutch discs clutch OSHA occupational standards Clutch facings are the friction component before installation in the vehicle US the support they require manipulation known as facings are sold separated from clutch facings is performed by a group of mechanics of asbestos containing and occasionally grinding tasks that The manipulation countersinking riveting sanding not riveters and includes drilling the mechanics These manipulation activities are can potentially release asbestos fibers exposing This study analyzes personal asbestos expo- in studies conducted in income countries reported mechanics that manipulate clutch facings conducted in sures of transmission transmission repair shops TRS were Methods Air sampling campaigns in two Four workers employed in these TRS were sam- November 2012 and July 2013 in Bogot^Colombia n = 39 short personal samples pled i.e. three riveters and one supervisor Personal samples and background samples n 2 were collected n 49 area samples n = 52 blank samples n = 8 National Institute for Occupational Safety consecutive days following US American an in both TRS during 3-5 7400 and 7402. Asbestos samples were analyzed by and Health US NIOSH methods Industrial Hygiene Association accredited laboratory were exposed to asbestos concentrations Results On at least one of the days sampled all riveters the Colombian permissible limit value limit or that exceeded the US OSHA permissibleseh xpo osr urte personal samples collected two 4.3 exceeded Additionally from the seven min the US OSHA excursion limit of 1 fcm conditions and use of asbestos containing In this study we identified that the working that exceed both the Conclusions transmission mechanics to asbestos concentrations of transmission products expose for the health of these workers are Colombian and OSHA standards The potential consequences great concern KEYWORDS asbestos chrysotile clutch disc Colombia exposure assessment transmission mechanics _ Oxford University Press on behalf of the British Occupational Hygiene Society 'The Author 2014. Published by Downlade from http // anhyg oxfordjournals oxfrdjunals orgorg by Jenifer Wods on Novembr 14 2014 Page . Asbestos exposure of transmission mechanics 30-60 of the friction material Yeung et al 1999 INTRODUCTION have not been detected containing materials are good acoustic biological Jiang et al 2008 Amphiboles in previous studies of transmission mechanics Blake heat and fire insulators and resist thermal and Mason 2002 et al 2008 Jiang et al 2008 Beginning in the 1980s and chemical attack Thompson of these characteristics asbestos has been chrysotile was gradually replaced in clutch products with other asbestos substitutes Because wide of industrial products such as used in the USA used in a range friction products e.g. brake and Jiang et al 2008 for thermal insulations In 1975 the US National Institute transmission products of vehicles building materials Occupational Safety and Health US NIOSH and resistant textiles Pierce et al 2008 warned about the potential risk of asbestos exposure A causal association between asbestos exposure that handled asbestos containing brake and several diseases has been established IARC of workers 1975 In addition for Research on parts and clutch discs NIOSH 1998 The International Agency assessment studies conducted in Cancer IARC has classified all types of asbestos to several exposure Australia and USA have concluded that transmis- amphiboles i.e. chrysotile and as carcinogenic mechanics are exposed to asbestos concentra- humans Group I LARC 1998 Some of the diseases sion with both the US OSHA PEL that might result from the inhalation of asbestos fib- and mesothelioma tions in compliance and EL Yeung et al 1999 Boelter et al 2007 ers include lung cancer asbestosis Blake et al 2008 Cohen and Van Orden 2008 Kanarek 2011 Every year asbestos exposure is occupational cancer deaths Jiang et al 2008 These studies describe the activimechanics as only responsible for half of the ties performed by transmission worldwide OMS 2004 the entire old clutch disc and replacing it In 2011 the Colombian Ministry of Social removing et al 2007 Blake et al Protection established for the first time an asbes- 007 with a new one Boelter 2008 Cohen and Van Orden 2008 Nevertheless tos occupational standard i.e. Resolution the there is study conducted in Japan during the 1980s 2011 MSPS 2011 In Resolution 007 in 2006 that reports high PCM con- Conference of Governmental Industrial and published activities i.e. Hygienists American ACGIH threshold limit value TLV centrations due to the manipulation machine grinding and leveling of brake linings for asbestos was adopted as the Colombian permis- in three companies involved in sible limit value PLV Thus the Colombian PLV is and clutch facings of automobile brakes and clutches the reprocessing 0.1 f cmfor an h time weighted average TWA PCME asbes- Sakai et al 2006 phase contrast microscopy equivalent Previous studies of our research group conducted tos concentration We use the term PCME to mean mechanics in Bogot^found that the manip- corrected for asbestos content as described on brake brake products e.g. counts that this is different ulation of asbestos containing below It is important to note ISO 10312 grinding drilling resulted in the release of impor- from the meaning of PCME in of asbestos fibers exposing the work- ISO 1995 In the USA the Occupational Safety tant amounts et al 2012 2014 Transmission permissible and Health Administration US OSHA 0.1 f ers Garc^>a mechanics could be facing a similar situation since limit US OSHA PEL for asbestos is exposure The US asbestos containing clutch facings i.e. the friction cmfor an h TWA PCME concentration of clutch discs are commercialized OSHA has also established an excursion limit US cinomCpoolnoemnbtia detached from the clutch plate i.e. OSHA EL of 1 cmPCME asbestos concentration Instead metallic support The clutch disc is comprised attached to the clutch plate for min exposure period OSHA 2013 used of two clutch facings of using the term US OSHA EL we previously and clutch facings that are detached from the plate the term short term exposure limit STEL Cely- before installation The cur- require manipulation of Garc^>aet al 2012 2014 used rent study analyses personal asbestos exposures Asbestos containing clutch parts have been mechanics during the manipulation since the early 20th century Cohen and Van Orden transmission of asbestos containing clutch facings in 2008 Jiang et al 2008 Traditionally chrysotile was comprising process Bogot^Colombia the type of asbestos used in clutch parts Downloade Downloade from htp:/anhyg.oxfrdjournals.org htp:/anhyg.oxfrdjunals.org htp:/anyg.oxfrdjunals.og htp:/anhyg.oxfrdjounals.org htp:/anhyg.oxfrdjournals.org htp:/anhyg.oxfordjournals.org , by Jenifer Wods on Novembr 14,2014 14,2014 Asbestos exposure of transmission mechanics Page 3 of 15 the use of compressed air or rags to clean the system METHODS the case for the workers sampled in this In 2012 a comprehensive and detailed census ofbrake of Bogot^ this was not study To avoid induced bias from the sampling their repair shops located in an area of the city all workers were instructed to conduct developed where automotive repair shops cluster was campaign modifications The activities of this database three trans- daily activities without Short- During the development were recorded in activity diaries mission repair shops TRS were identified Two performed were collected during the of these shops i.e. TRS1 and TRS2 collaborated term personal samples of clutch facings and during methods and design were manipulation activities with this study The study activities The duration of the partial period the Ethics Committee of Universidad de cleaning were con- approved by the TRS that sample was longer when no manipulations participated los Andes and workers from ducted since air fiber concentrations were expected in the study signed an informed consent be low Blank samples were collected for each sam- Personal partial period personal 30 min and area to and background samples were collected dur- air samples were collected during 3 consecutive days and 5 consecutive pling day ing one night at each shop All personal samples were and blank in TRS1 8-10 November 2012 2013 during the work- analyzed by PCM and TEM Background days in TRS2 11-15 July the filters samples were analyzed by PCM shift To reduce the chances of overloading and methods were similar to those the collection of air samples the work Study design research group Cely- during period was divided into shorter sampling win- used in previous studies by our Garc^>aet al 2012 2014 Air samples were collected dows Air sample collection and analysis followed US AIRChek XR5000 pumps SKC Eighty NIOSH methods 7400 NIOSH 1994a and 7402 operated using Four PA USA at a flow rate of ~ LPM conwith mm con- NIOSH 1994b US NIOSH method 7400 provides nected to mm cassettes equipped PCM fiber counts using phase contrast microscopy according to extension cowls holding mm MCE filters ducting Preloaded Cassette SKC- and reports total fiber concentration US NIOSH method 7402 with 0.45 ...mpore SKC and at selected counting rules TEM to Inc. Flow rates were calibrated at the beginning utilizes transmission electron microscopy the end of each sampling window using a Defender 510 determine fiber identity and provides asbestos fiber observed fib- High or 520 High BIOS International Calibrator BIOS standard pro- counts asbestos type and the fraction of International Butler NJ USA following ers that are asbestos cedures Samples were reported as suspect if the differ- Personal samples were collected in a group of TRS the initial and final flow was above % known as riveters who manipulate asbestos ence between Forensic Analytical workers to attach Samples were analyzed by and asbestos containing clutch facings Laboratories Inc. Forensic Analytical Laboratories them to the clutch plate before installation in the CA USA an American Industrial vehicle In TRS1 there were two riveters R1 R2 in AIHA and spo- Inc Hayward Hygiene Association accredited laboraVoluntary charge of the manipulation of clutch facings third in the National tory that also participates on the amount of work a radically depending of the TRS also Accreditation Program NVLAP TEM Laboratory volt- worker W1 who is the supervisor manipulations In TRS1 workers R1 R2 analysis was performed at 100 kV accelerating and -2500x magnification to count fibers 5 ...m paenrdfWor1meddid not repair the transmission system of the age CM12 TEM Eindhoven Netherlands vehicles they only prepared the transmission parts in and did not use using a Philips installed in 1991 A magnification of 10000x was and countability of order to install them in the vehicles used to determine fiber dimension air The workers in charge of repairing any compressed to 5 The energy dispersive X fibers close in length ...m worked in a differthe vehicle's transmission system In TRS2 the riveter analyzer EDXA instrumentation was manufac- ray USA installed in 2007 ent area and were not sampled was also tured by Evex Princeton NJ R3 conducting the manipulation processes and consists of a quantum dot detector QDD with the mechanic in charge of repairing the vehicle's trans- window and digital MCA analyzer and mission system R3 reported that he does not clean repairing standard Dot power supply Forensic Analytical Laboratories the vehicle's transmission system Although of the vehicle could involve personal communication the transmission system Downlade from htp:/anhyg.oxfrdjournals.org htp:/anhyg.oxfrdjunals.org htp:/anyg.oxfrdjunals.og htp:/anhyg.oxfrdjounals.org htp:/anhyg.oxfrdjounals.org by Jenifer Wods on Novembr 14 2014 Page Asbestos exposure of transmission mechanics differences on the 8h PCME PCME personal concentrations were used to comthe US OSHA not result in important concentrations In fact the sensitivity analysis showed did not pare against both the Colombian and PCM that the compliance status of the samples standards To estimate PCME concentrations of asbes- when using the LOD instead of LOD When change the worker left the concentrations were corrected with the fraction shifts ended before 8h or by tos fibers to total fibers F reported TEM NIOSH dif- were assumed as 0f cmfor shop fiber concentrations work 1994b Note that this usage of the term PCME is the time remaining to complete the ferent from that in ISO 10312 ISO 1995 collected in both shops at a The US OSHA PEL and Colombian PLV set limits of Area samples were breathing height of 1.5 m In TRS1 the collection of for asbestos personal exposures during shifts was done to determine if fibers could h day Nevertheless in multiple occupations in per mechanics involved area samples outside the manipulation area MA expos- migrate TRS1 the Colombia as happened with the is The ing administrative staff or customers In in the current study the daily work longer office facilities were physically separated from the to deal with shifts extending beyond approach standards i.e. US OSHA and area samples with a duration manipulation area OF and the office entrance 8h differs between the two of h were collected at physically PEL and Colombian PLV One of the options recom- TRS2 did not have separated mended in the US OSHA Technical Manual is using at the MA had one large area where windows that add up areas since this shop only the worst partial period sampling both administrative and repair activities were con- 8 h for each work to estimate the h TWA PCME the ducted To assess fiber migration in TRS2 short concentration for comparison purposes against collected at 1 m A1 and m A2 US OSHA PEL OSHA 2008 This approach was area samples were from the manipulation equipment i.e. emery disc used in the current study For short personal simultaneously to the short personal samples 1 the min PCME personal concentrations samples US OSHA EL of 1 cm collected during the manipulation processes Fig in each TRS were compared against the shows the location of the area samples In the case of the Colombian PLV the regulation work exceeds 8h the area samples were analyzed by PCM and in TRS2 1 and 2 m during days in which stipulates that when the be PLV must adjusted following equations 1 and 2 area samples collected at the US OSHA the 8h personal concentration exceeded MSPS 2011 PEL were also analyzed by TEM i.e. Day 1 and 2 Asbestos percent bulk content of the most common clutch facings used in the shops sampled was deter- method EPA 93-116 PLM by mined using None of the labels of Forensic Analytical Laboratories asbestos content However specified PLVC 2 the clutch facings from the workers regarding their we received feedback where CF is a correction factor hd is the number of hours worked per day and PLVC is the corrected PLV In TRS1 the work was 8.5 day and in TRS2 was day For comparison purposes against the Colombian PLV the adjusted PLV is 0.091 f cmfor TRS1 and 0.083 f cmfor TRS2 were below the limit When PCM concentrations of detection LOD half of the LOD was used of asbestos content Two of the brands sent pfeorrcaenpatlyisoins were reported as asbestos containing prodand the third brand was reported as asbestos free ucts To capture potential variability of asbestos content four clutch facings per brand were analyzed and relative humidity were recorded on Temperature Relative Humidity using HOBO U10 Temperature Data Logger U10-003 ONSET Bourne MA USA To determine the potential for calculation purposes of using half of the LOD instead of the impact was conducted in personal LOD a sensitivity analysis windows that had concentra- samples with sampling showed tions below the LOD The sensitivity analysis that using the LOD instead of half of the LOD did RESULTS Description of the TRS 8.5h per day on weekdays and 5h TRS1 operates -9h from Monday to on Saturdays TRS2 operates Downlade from http /anhyg.oxfrdjounals/anhyg.oxfordjournals /anhyg.oxfordjournals /anhyg.oxfrdjournals /anhyg.oxfrdjunals /anhyg.oxfrdjournals org by Jenifer Woods Wods on Novembr 14 2014 a \ | | Asbestos exposure of transmission mechanics Page of | b 10m | k 4m f Emery nes Manipulation area \ ' i Work area J 12m s Manipulation Manipulation Manipulation area of r-) Emery disc fi 12m i | | Table | | 0 Office Table Table i Warehouse Table /| 4m | 1 \ NO | sample sample AZ 1 Day > sample Days 2 4 ) @ Office and warehouse area sample OF @ Manipulation sample MA : meiminanasertsnanraninmsnimamencstd 1 a Location of area samples in TRS1 vertical view b Location of area samples in TRS2 vertical view Saturday Both TRS use asbestos containing clutch facings and TRS1 sporadically uses asbestos containing clutch facings i.e. glass fiber Table 1 presents a description of the TRS involved in the study Description of manipulation activities of clutch facings At the TRS sampled clutch facings are sold without holes and separated from the clutch plate Using the activities diaries kept during the sampling campaigns to reconstruct the tasks involved in the it was possible manipulation process required to attach clutch facings of clutch to the clutch plate The manipulation process facings is the same for all types of manual transmissions i.e. both heavy and passenger vehicles Once the clutch disc has been uninstalled from the transmission system starts with the removal of the the manipulation process rivets from the old clutch facings using a drill The new clutch facings are attached to the old clutch plate using a wrench and holes are drilled in the clutch facings matching the holes of the clutch plate Then the holes on the clutch facings are countersunk and if drilling the clutch facings leaves an irregular surface surround- ing the holes the surface is sanded In TRS2 the riveter rubbed one clutch facing against the other to remove If the debris Subsequently the clutch facings are riveted to the plate the size of the facings does not match the plate facings are ground with an emery disc Sometimes clutch facings for specific vehicles are not commercially available or they are not in stock In such occasions riveters need to adjust clutch facings of size to the clutch plate which includes cutting improper A flow- the edges grinding and sanding the products chart of the manipulation process is presented in Fig 2 Air samples results A total of 150 samples were collected in the TRSS including 39 personal samples of different duration Downlade from http an hy g oxfrdjunals orgorg by Jenifer Wods on Novembr 14 2014 Page of Asbestos exposure of transmission mechanics Table 1. Description of TRS Shops characteristics Type of vehicles serviced Number of clutch discs manipulated TRS1 TRS2 Prepares transmission parts for heavy and passenger vehicles serviced at the shop and at other nearby TRS Prepares transmission parts for vehicles exclusively serviced passenger at the shop ~ 12 per day Workers involved in clutch discs preparation Area of the shop ceiling height Description of office and warehouse Description of manipulation area 2 Riveters R1 R2 1 Riveter R3 1 Supervisor W1 160 mwith a ceiling height between 48 mwith a ceiling height -3.5 m 3.5 and 4.5 m Office and warehouse area of 20 mphysically separated from the manipulation area Warehouse access is through the office Office door located at 10 m from the manipulation area The doors the office and the warehouse remained Office and warehouse area shared space with manipulation area Work desk located at ~ m from the manipulation area close to the exit door Exit door remained open during _ the entire work open during the entire work Area of 13 mThe manipulation area was embedded in larger area where other mechanics performed Area of 4 mwith a ceiling height of m which was 0.5 m lower than the rest of the shop Manipulation equipment and materials Ventilation system their work 1 drill 1 drill 1 countersink 1 countersink 1 rivet machine 1 emery machine with emery stone and emery disc 1 rivet machine 1 emery machine with emery stone and emery disc Sandpaper Consisted of a made extractor hood located above the countersink and rivet machines which was rarely operated There are two skylights in the roof one located above the manipulation area which remained open during the sampling days Two exit doors remained open during the Sandpaper No ventilation system in the shop except for the natural ventilation provided by the exit door This door remained open during the entire work Downloaded Downloade from http anhyg anhyg annhyg oxfrdjunals.org oxfrdjournals.org by Jenifer Wods on Novembr 14,2014 14,2014 Asbestos exposure of transmission mechanics Page 7 of 15 Table 1. Continued Shops characteristics TRS1 TRS2 Cleaning activities of the manipulation Every day at the end of the shift the Cleaning activities under dry area shop was cleaned This was done after conditions were performed once sprinkling small amounts of water on the floor Occasionally workers during the sampling campaign at the end of the week removed dust from the machines with their hand or a broom in dry conditions Respiratory protection equipment Workers wore working clothes Worker wore working clothes In some cases workers used The riveter used a half piece inappropriate respiratory protection purifying respiratoron top of a Downlade including a piece of cloth or a filtering filtering piece respirator Neither piece respirator to cover their respirator met the recommendations from nose and mouth for asbestos protection Respirators were loose and occasionally the nose http was uncovered anhyg annhyg Remove the clutch disc from the oxfordjournals transmission system oxfrdjunals Will clutch No plate support be reused org org Yes by Drill the rivets to separate old Jenifer clutch facings from the clutch plate L Hold the new clutch facings to the clutch plate with wrench Wods I _| Drill the new clutch facings ne a nw ew clutch plate matching the clutch plate holes on L Novembr | Countersink the clutch facings holes | Do clutch facings have 14 debris 2014 Sand clutch facings or rub one facing against the other I [ Rivet clutch facings to the clutch plate kJ Do clutch facings have an appropiate size No Grind the clutch facings to adjust size I [ Install the clutch disc in the vehicle k 2 Manipulation process of clutch facings Page 8 of 15 Asbestos exposure of transmission mechanics 49 short personal samples 52 area samples 8 above both standards during two sampling days i.e. blanks and 2 background samples Chrysotile fibers Day 1 Day 2 and was exposed to asbestos were the only type of asbestos identified in the sam- concentrations exceeding 50 of the US OSHA PEL ples collected in both TRS Eleven TEM fiber counts and the Colombian standard during Day 5 i.e. R3- were below the analytical sensitivity One sample was Day 5 Supplementary Table S1 available at Annals suspect because the flow drift was greater than % i.e. of Occupational Hygiene online presents all min 5.47 Another three samples were labeled as suspect short personal asbestos concentrations and the because the conducting extension cowls were accidentally opened when detaching them from the pump description of the manipulation or cleaning activities associated with each sample For the concentra- although the filter remained in the cowl and the cowl tions presented in Supplementary Table S1 available was immediately sealed again One filter was reported at Annals of Occupational Hygiene online when the by the laboratory as loaded with particulates i.e. R1 sampling window was shorter than min 0f 0f cm Downlade Day1 ST3 All these samples were used in the TWA calculations and reported in footnotes b and g in Table 2 and footnotes d f and g in Table 3. No fib- was assumed for the remaining time It is important to highlight that all the min PCME short personal samples collected in TRS1 were below the US from ers were found in the blanks and both background OSHA EL However four samples had TEM concen- http samples collected had PCM concentrations below the LOD trations above 0.5 f cmand one sample was above 1 fcmTwo min PCME short personal sam- an hyg During sampling days temperature in TRS1 ranged ples collected in TRS2 exceeded the US OSHA EL of between 15 and 24 in the MA and between -19 1 cmEleven percentage of all the short per- annhyg and 22 in the office area Relative humidity ranged sonal samples collected in both shops were above 50 oxfordjournals oxfrdjunals between 36 and 70 in the MA and between 38 and 60 in the office area In TRS2 temperature and relative humidity were sampled at 1 and 2 m from of the US OSHA EL During manipulation asbestos containing activities of asbestos and clutch facings presented the manipulation equipment i.e. A1 and A2 respec- in Supplementary Table S1 available at Annals of oorrgg tively Temperature ranged between 17 and 22 Occupational Hygiene online workers reported which by in both sampling points and relative humidity ranged between and 72 in sample point Al and between WJeonidfesr 47 and 67 in sample point A2 type of products was used The asbestos content bulk analysis showed that the two brands reported by the workers as containing products had a 20 content of chrysotile There was no variation in Personal air samples results asbestos content between the four clutch facings ana- on Table 2 presents the results of the 8h TWA and 8.5h lyzed per brand The four clutch facings of the brand Novembr TWA personal asbestos concentrations in TRS1 for comparison purposes against the US OSHA PEL and reported by workers as asbestos free had a 25 content of fibrous glass and asbestos were detected the Colombian PLV respectively Both riveters sam- Additionally Supplementary Tables S2 and S3 14 pled in TRS1 were exposed to asbestos concentrations available at Annals of Occupational Hygiene online pre- 2014 not in compliance with both the US OSHA PEL and sent the results of all the personal samples collected in the Colombian PLVc during the first sampling day i.e. TRS1 and TRS2 respectively Day 1 Day 1 and were exposed to asbestos Table 4 summarizes the h TWA and min concentrations above 50 of the US OSHA PEL and the Colombian standard during the second sampling day i.e. Day 2 Day 2 The supervisor in PCME short asbestos concentrations of per- sonal samples collected in both TRS sampled TRS1 i.e. W1 was exposed to asbestos concentra- tions below both US OSHA and Colombian standards Area air samples results in all the days sampled PCM area concentration results Table 3 presents the results of the 8h TWA and 9h TWA personal asbestos concentrations in TRS2 Riveter R3 was exposed to asbestos concentrations In TRS1 the three h TWA PCM office area concen- trations collected on Days 2 and 3 were 0.009 0.002 and 0.005 f cmrespectively The corresponding h Table 2. PCME h TWA and 8.5 TWA personal asbestos concentrations for workers sampled in TRS1 Worker Number sampling sampling __ time min windows PCME concentration using total sampling time f cmnfl US OSHA STANDARD 0.1 cm for h TWA Time assumed with cm complete h TWA min PCME concentration concentration f cm COLOMBIAN STANDARD 0.091 fcmfcm for 8.5 TWA Time assumed with cm cmcomplete 8.5 TWA min 8.5 TWA PCME concentration concentration f cm Day 1 11 508 0.103 Day 2 5 495 0.064 _ 0.108b 2 0.066 15 0,103b 0.062 Day 3 4 270 0.042 210 0.024 240 0.022 Day 1 12 510 0.107 0.111 0 0.107d Day 2 13 480 0.077 0 0.077b 30 0.073b Day 3 6 263 0.088 217 0.048 247 0.046 Day 1 2 533 Day 28 7 553 0.013 0.012 0.013 0.014b Asbetos 0.013 0.012b Day 3 1 285 0.010 195 RI Riveter 1 R2 Riveter 2 W1 worker 1 0.006 225 0.006 exposure of PCME concentrations calculated based on PCM concentrations chrysotile fiber counts and F ratio which are shown in detailed for each sample is available as Supplementary Table S2 at Annals of Occupational Hygiene online transmi o TWA PCME concentration includes sampling window with PCM concentrations LOD Total asbestos fibers ratio was multiplied by halfofthe LOD for sampling window with PCM concentrations LOD 8 TWA PCME concentration not in compliance with OSHA PEL of 0.1 fcmfl 48.5 TWA PCME concentration not in compliance with Colombian PLVC of 0.091 fcmfl` 8 TWA PCME concentration calculated using the worst h of the work shift according with the US OSHA Technical Manual OSHA 2008 Samples were collected during 533 min this day TWA PCME concentration was estimated for the total sampling time and compared against the Colombian PLVc of 0 085 cm of mechanis TWA estimation includes concentrations from samples W1 Day2 P2 and W1 Day2 ST2 in which the conducting extension cowl were accidentally opened at the end the sample collection Cowls were immediately closed and the filter always remained in the cowl Samples were collected during 553 min this day TWA PCME concentration was estimated for the total sampling time and compared against the Colombian PLVc of 0.080 cm Page 9 of 15 07 d j qwtonto spot d iun Aq -djo sprumofpiojor^sprumofpijor^ quue dny woj p projumo -> Page 10 of 15 Table 3. PCME h TWA and h TWA personal asbestos concentrations for workers sampled in TRS2 Asbetos _ Worker Number sampling TWA PCME US OSHA STANDARD 0.1 cm for COLOMBIAN STANDARDSTANDARD f sampling time min concentration using h TWA cmfor h TWA windows totalsampling exposure time cm Time assumed with PCME Time assumed with 0 h TWA PCME complete concentration fcmcomplete h concentration h TWA min fcm TWA min of fcm Day 1 7 461 0.159 19 Day 2 7 475 0.195 5 Day 38 4 479 0.024 1 Day 4 4 513 Day 5 5 523 0.032 0.057 0.153b 79 0.193b 65 0.025 61 0.034b 27 0.061b 17 transmio 0.136d 0.172e mechanis 0.022f 0.030 0.050 R3 Riveter 3 PCME concentrations calculated based on PCM concentrations chrysotile fiber counts and F ratio which are shown in detailed for each sample is available as Supplementary Table S3 at Annals of Occupational Hygiene online 8 TWA PCME concentration calculated using the worst h of the work shift according with the US OSHA Technical Manual OSHA 2008 8 TWA PCME concentration not in compliance with OSHA PEL of 0.1 fcm a of TWA PCME concentration includes a suspect sample that had flow drift of 5.4 with a sampling time of min and a PCME concentration 1.084 fcm 9 TWA PCME concentration not in compliance with the Colombian PLVc of 0.083 fcm of the TWA PCME concentration includes sampling window with PCM concentrations LOD Total asbestos fibers ratio was multiplied by half LOD for sampling window with PCM concentrations LOD TalWwaAys ersetmiamianteiodninintchleudceoswcloncentration from sample R3 Day3 P3 in which the conducting extension cowl was accidentally opened at the end of the sample collection Cowl was immediately closed and the filter t102 t Iaquaron uo spoot Jejuuaf fq to sppuiopopo que d cuuolf papeojunod Table 4. Statistical summary ofPCME personal asbestos concentrations found in the TRS sampled Type ofsample Worker shop Total number number above the US OSHA PEL or EL PCME asbestos concentrations fcm Mean SD Median Min Max h TWA personal samples Short personal samples R1 TRS1 TRS1 R3 TRS2 TRS1 R1 TRS1 R2 TRS1 R3 TRS2 W1 TRS1 3 1b 3 1b 5 2b 3 0b 12 0 23 0d 11 2" 3 0d 0.066 0.079 0.093 0.011 0.172 0.105 0.603 0.065 R1 Riveter 1 R2 Riveter 2 R3 Riveter 3 W1 worker 1 Calculated using the h TWA PCME asbestos concentrations shown in Tables 2 and 3 Column 6 Values compared against the US OSHA of PEL 0.1 fcm of Based on the min PCME asbestos concentrations shown in Supplementary Table S1 Column 5 available at Annals of Occupational Hygiene online Values compared against the US OSHA EL 1 cmfl 0.042 0.032 0.076 0.004 0.088 0.048 0.443 0.076 0.066 0.077 0.061 0.013 0.195 0.110 0.432 0.021 0.024 0.108 0.048 0.111 0.025 0.193 0.006 0.014 Asbetos 0.021 0.022 0.332 0.212 exposure 0.223 0.021 1.653 0.153 of transmio mechanis Page 11 of 15 tl0Z t Iaquason uo spoor Jajuua fq ao ptumofpaoJo ~ ^ uuucehu uolf papeojunod Page 12 of 15 Asbestos exposure of transmission mechanics TWA PCM MA concentrations collected on Days 1 2 and 3 were 0.017 0.010 and 0.015 f cmrespec- tively In TRS2 the h TWA PCM Al area concentrations ranged between 0.007 and 0.050 f cmi.e. collected during 5 days For A2 the h TWA PCM area concentrations ranged between 0.006 and 0.183 f cmi.e. collected during 5 days riveters These manipulations are required because clutch facings are sold detached from the support In the TRS sampled most of the clutch facings used contained asbestos Riveters sampled have to perform manipulation activities including drilling countersinking riveting sanding and grinding clutch facings which release asbestos fibers and expose workers All riveters sampled were exposed to compliant PCME area concentration results asbestos concentrations when compared to the US Eight TWA PCME area concentrations in TRS2 OSHA PEL and the Colombian standard Moreover were estimated for Days 1 and 2 in sampling points Al some manipulation activities resulted in asbestos 1 m and A2 2 m Fig ) because on these days exposures exceeding the US OSHA EL Although Downlade personal samples showed high asbestos exposures of the riveter R3 For this analysis fiber concentration was assumed as of of cmduring periods when samples ready to install clutch discs are commercially available they are more expensive and were less common in the TRSs sampled were not collected One of these h TWA area con- To the best of our knowledge this is the first study from centrations exceeded 0.1 f cmi.e. A2 Day 2 = 0.183 that reports asbestos exposures on transmission htp:/anhyg.oxfrdjournals.org f cmrecognizing that area samples should not be mechanics i.e. riveters in low- and income htp:/anhyg.oxfrdjunals.org used to determine regulatory compliance The other h TWA PCME area concentrations Al Day 1 and countries The results obtained in this study are dif- ferent from the results of the small number of studies 2 and A2 Day 1 had quantifiable asbestos concentra- conducted on this occupational group in income htp:/anyg.oxfrdjuls tions ranging from 0.024 to 0.050 fcm Comparison ofPCME short personal and short countries In 1999 a study conducted in Sydney Australia found that during the replacement process of a clutch disc PCM concentrations were below the area concentrations 0.05 cmYeung LOD f htp:/anhyg.oxfrdjounals.org et al 1999 A study from htp:/anhyg.oxfrdjournals.org A preliminary analysis was conducted to determine the USA evaluated personal exposures to asbestos by Jenifer the migration of fibers in the work area during the manipulation activities For this during Days 1 and among transmission mechanics during activities that included unpacking repacking and stacking boxes Wo ds 2 short min area concentrations were col- lected in TRS2 at points A1 and A2 while riveter was cleaning asbestos containing clutch discs and clothes handling This study found that personal asbestos con- manipulating asbestos containing products PCME centrations were in compliance with the US OSHA on Novembr min Al concentrations ranged between 0.091 and 0.207 fcmminute PCME A2 concentrations ranged between 0.069 and 1.715 f cmPCME con- PEL and EL and reported that the highest exposures were associated with stacking unopened boxes Jiang et al 2008 Another study conducted in USA in 2003 centration of sample A2 Day2 ST2 exceeded 1 f cm analyzed asbestos exposures during the removal and 14 Recognizing that the number of samples is small replacement of containing materials in heavy 2014 no clear patterns associating asbestos concentration vehicles i.e. gaskets brakes and clutch parts In this with the distance to the manipulation equipment was study authors reported that the PCME short per- observed Supplementary Table S4 available at Annals sonal asbestos concentrations ranged between 0.043 of Occupational Hygiene online shows in detail the and 0.099 f cmand TWA PCME concentrations min personal sample PCME concentrations and the corresponding min PCME area samples at a ranged between 0.011 and 0.052 fcmduring different sampling periods i.e. from 336 to 574 min Boelter distance of 1 m A1 and 2 m A2 from the manipu- et al 2007 Finally Blake et al 2008 reported that lation equipment during the installation of a clutch disc the h TWA PCME chrysotile asbestos concentration was 0.0011 DISCUSSION fcmBlake et al 2008 All these studies concluded This study describes the manipulation activities of that transmission mechanics are not at excess risk of asbestos containing clutch facings performed by developing asbestos related diseases Yeung et al Asbestos exposure of transmission mechanics Page 13 of 15 1999 Boelter et al 2007 Blake et al 2008 Jiang some potential explanations for this First based on the et al 2008 However none of the previous studies activity diaries filled during sampling campaigns R3 report the manipulation activities conducted by the frequently rubbed one clutch facing against the other to riveters sampled in the current study Thus a potential eliminate debris and this activity was often performed explanation for the low asbestos exposures reported in close to his respiratory zone In contrast riveters in studies conducted in income countries involve TRS1 used sand paper for this task and in only one the fact that in these countries clutch discs can be occasion during the sampling campaign one worker directly installed in vehicles without manipulating in TRS1 i.e. R1 rubbed clutch facings i.e. sample clutch facings It is important to highlight that there R1 Day2 ST2 in Supplementary Table S1 available at is one study conducted in Japan during the 1980s and Annals of Occupational Hygiene online Second clean- published in 2006 that reports manipulation activities ing activities of the MA were uncommon in TRS2 and on brake linings and clutch facings Instead of trans- old clutch facings and damaged clutch discs were dis- Downlade mission mechanics or riveters these workers were involved in the reprocessing of automobile brake and clutches Sakai et al 2006 Although the occupation posed on the floor Thus asbestos fibers could be resuspended creating an additional source of exposure Finally TRS2 was a small shop with a smaller MA and was different workers from the Japanese study and the a lower ceiling in comparison to TRS1 Thus ventila- from current study manipulated asbestos containing clutch tion conditions were worst in TRS2 an hy parts and asbestos exposures of workers sampled in There were two min short personal samples both studies are extremely high Unfortunately the collected during the manipulation activities of clutch Japanese study only reports PCM concentrations facings that the riveters reported as asbestos free i.e. g although they used TEM to identify the type of fibers R2 Day3 ST10 and W1 Day2 ST2 in Supplementary oxfordjournals oxfrdjunals found i.e. chrysotile As expected days with the highest number of manipulations resulted in the highest h TWA Table S1 available at Annals of Occupational Hygiene online and no other activity was performed during these sampling windows However these samples had PCME personal asbestos concentrations Focusing asbestos fibers This phenomenon was also described org on the h TWA PCME personal asbestos estimates in similar studies of brake mechanics in Bogot^Cely- by Jenifer 29 4 out of 14 exceeded both the US OSHA PEL and the Colombian PLVc Focusing on the PCME Garc^>aet al 2012 2014 As it was explained by CelyGarc^>aet al the manipulation equipment may have Wo ds min short personal samples 4.1 2 out of 49 exceeded the US OSHA EL been contaminated with asbestos fibers during previous manipulation activities and fibers may have been The supervisor in TRS1 WI was the only worker suspended Another potential explanation was that on sampled who was not exposed to asbestos concentra- although riveters reported clutch facings as asbestos Novembr tions above the US OSHA or Colombian standards This could be explained because this worker rarely free they might have contained asbestos Area samples collected in both shops suggest that 14 manipulated clutch facings and during sampling Days other workers not involved in the manipulation activi- 1 and 3 did not conduct any manipulation activity ties may be exposed to asbestos fibers One short 2014 However personal samples of W1 indicate exposure area sample collected at 2 m from the manipulation to asbestos fibers This is important because even at equipment was above the personal sample collected concentrations in compliance with the regulations on the riveter performing the manipulation However there is a risk of developing asbestos diseases the concentrations of both samples were similar OSHA 1995 Similarly to W1 other workers and Personal sample R3 Day2 ST2 = 1.653 f cmarea customers that share work areas with riveters may be sample A2 Day2 ST2 1.715 f cmThese samples exposed to asbestos fibers were collected while the riveter R3 was cutting the Riveter 3 in TRS2 had two samples that exceeded edges of two clutch facings and then sanding and the US OSHA EL R3 also had the highest h TWA grinding them Because of the location of the door in PCME asbestos concentrations among all work- the TRS Fig 1 one potential explanation for this ers sampled exceeding the US OSHA PEL and result is that the wind may have blown the fibers away Colombian PLVC in 2 of the 5 days sampled There are from the riveter toward the sampling equipment Page 15 Asbestos exposure of transmission mechanics Workers in shops sampled occasionally used personal protection equipment PPE not designed for asbestos protection i.e. filtering face piece respirators and clothes The TRS also lacked adequate ventila- tion systems TRS2 did not have any ventilation sys- asbestos containing clutch facings because they are sold separated from the clutch plate the lack of training on the risks resulting from working with asbes- containing products and the absence of proper engineering controls and PPE raises serious concerns tem and the extraction hood of TRS1 was operated in about the potential implications that all these factors Downlade rare occasions Moreover PPE is at the bottom in the hierarchy of occupational control options and other alternatives such as source interventions should be prioritized when trying to reduce the risks of these workers From an industrial hygiene perspective the best option to eliminate the risk of asbestos exposure among transmission mechanics would be to produce asbestos free clutch facings Another less desirable may have on the respiratory health of these workers Similarly to what we have found in Colombia work- ers in other low- and income countries may be experiencing unacceptable occupational risks resulting from asbestos exposure Thus it is important to expand our knowledge regarding the risks result- ing from the continuous use of asbestos containing products worldwide The authors recommend that the health environmental and labor authorities in option would be to commercialize ready to install Colombia should consider requiring as a transitory from containing clutch disks in TRS2 a clutch provision preassembled containing friction disk ready to install was used in one occasion which products when containing products are used http did not require any manipulation The authors strongly recommend that the production an hy Recognizing that more studies are needed to and use of containing products in the coun- g.oxfordjournals.org improve our understanding of asbestos exposures try should be severely restricted or banned g.oxfordjournals.org among mechanics that manipulate asbestos contain- g.oxfrdjunals.org Engineering ing products the results for transmission mechanics FUNDING observed in the current study suggest that they expe- The financial rience higher exposures than passenger vehicle brake Department of Cisvuilppaonrdt Enwvaisronmpernotvailded by the g.ogx.fooxrfdrjdojuorunranlasl.so.rogrg , mechanics Garc^>aet al 2012 2014 In com- of Universidad de los Andes for the by parison to heavy vehicle brake mechanics asbestos this study development of exposures seem to be similar Jenifer The findings of this study confirm the importance ACKNOWLEDGMENTS Wo ds of being cautious when translating the results of The authors thank Forensic Analytical Laboratories occupational studies from high income to low- and Inc. for the analysis of the samples The authors also on income countries The working conditions thank the workers that characteristics of the products used tasks performed participated in the study and the owners of the BRS that gave us permission to con- Novembr by workers workers training and the enforcement of duct the sampling campaigns on their premises regulations to protect workers may have major differ- The authors have no interest to declare 14 ences between countries even when comparing the 2014 same occupations REFERENCES CONCLUSIONS Although the workers in the TRS sampled reported that the number of clutch facings manipulations has decreased over time the exposure concentrations found are high Thus this group of transmission mechanics is at excess risk of developing asbestos- related diseases Furthermore workers that do not manipulate clutch facings may be exposed to high asbestos concentrations in the workplace The adverse working conditions of riveters the need to manipulate Blake CL Dotson GS Harbison RD 2008 Evaluation of asbestos exposure within the automotive repair industry a study involving removal of containing body sealants and drive clutch replacement Regul Toxicol Pharmacol 52 324-31 Boelter FW Spencer JW Simmons CE 2007 Heavy equip- ment maintenance exposure assessment using a activity model to estimate surrogate values for replacement of missing dataJ Occup Environ Hyg 4 525-37 Garc^>aMF S^nchezM Breysse PN et al 2012 Personal exposures to asbestos fibers during brake maintenance of passenger vehicles Ann Occup Hyg 56 985-99 Asbestos exposure of transmission mechanics Page 15 15 15 Garc^>aMF Duque CA M Dur^n et al 2014 Personal exposure to asbestos and respiratory health of heavy vehicle brake mechanics J Expo Sci Environ Epidemiol jes.2014.8 Epub ahead of print Cohen HJ Van Orden DR 2008 Asbestos exposures of mechanics performing clutch service on motor vehicles J Occup Environ Hyg 5 148 56 LARC 1998 Asbestos Summary of data reported and evalua- NIOSH 1994a Method 7400. Asbestos and other fibers by PCM Manual of analytical methods 4th edn Online Available at http://www.cdc.gov/niosh/docs/2003-154/ 7400.pdf Accessed 19 December 2013 NIOSH 1994b Method 7402. Asbestos by TEM Manual of analytical methods 4th edn Online Available at http www.cdc.gov/niosh/docs/2003-154/pdfs/7402.pdf www.cdc.gov/niosh/docs/2003-154/pdfs/7402.pdf Accessed 19 December 2013 tion IARC monographs on the evaluation of carcinogenicrisks to humans IARC monographs on the evaluation of carcino- OMS 2004 Selected occupational risk factors Comparative quantification of health risks Vol 2. Ch 21. Online genic risks to humans Volume 14. Online Available at http Available at http://www.who.int/healthinfo/global_bur-htp:/ww.who.int/healthinfo/global_bur- htp:/w.who.int/healthinfo/global_bur- www.iarc.fr/en/publications/list/monographs/ Accessed den_disease Accessed 19 December 2013 19 December 2013 ISO 1995 ISO 10312. Ambient air Determination of abestos fibres Direct transfer transmission electron microscopy method Online Available at htp:/ww.iso.org/iso/cata- http://www.iso.org/iso/cata- OSHA 1995 OSHA 3095 Rev Asbestos standard for general industry Online Available at //www.osha osha3095.pdf Accessed 19 December 2013 Downlade logue_detail.htm Accessed 27 May 2014 ISO 1999 ISO 13794. Ambient air Determination of asbes- OSHA 2008 Personal sampling for air contaminants OSHA technical manual OTM Section II Ch 1. Online from tos fibres transfer transmission electron microscopy Available at https://www.osha.gov/dts/osta/otm/otm_11/htps:/ww.osha.gov/dts/osta/otm/otm_1/ method Online Available at http://www.iso.org/150/ http://www.iso.org/150/ 1.html Accessed 19 December 2013 http /anhyg.oxfrdjounals catalogue_detail.htm Accessed 19 OSHA 2013 Asbestos Standard number 1910.1001 Online show_document December 2013 Available at https://www.osha.gov/pls/oshaweb/owadisphtps:/ww.osha.gov/pls/oshaweb/owadisp Jiang GC Madl AK Ingmundson KJ et al 2008 A study of / an hyg.oxfordjournals airborne chrysotile concentrations associated with han- Accessed 19 December 2013 /anhyg.oxfrdjunals dling unpacking and repacking boxes ofautomobile clutch discs Regul Toxicol Pharmacol 51 87 97 Kanarek MS 2011 Mesothelioma from chrysotile asbestos Pierce JS McKinley MA Paustenbach DJ 2008 An evaluation of reported effect chrysotile asbestos exposures for lung cancer and mesothelioma Crit Rev Toxicol 38 update Ann Epidemiol 688-697 191-214 org Ministerio de Salud y Protecci^n Social MSPS 2011 Sakai K Hisanaga N Shibata E et al 2006 Asbestos exposures Resoluci^n007 de 2011 Por la cual se adopta el reglamento during reprocessing of automobile brakes and clutches Int by de higiene y seguridad del crisotilo y otras fibras de uso similar Occup Environ Health 12 95-105 Jenifer Bogot^Colombia Ministerio de Salud y Protecci^nSocial Thompson SK Mason E. 2002 Asbestos mineral and fibers L Wo ds NIOSH 1975 Current Intelligence Bulletin 5 Asbestos Chem Health Saf 9 21 3 exposure during servicing of motor vehicle brake and clutch Yeung P Patience K Apthorpe et al 1999 An Australian assemblies Online Available at http://www.cdc.gov/niosh/http://www.cdc.gov/niosh/ study to evaluate worker exposure to chrysotile in the auto- on 78127 Accessed 19 December 2013 motive service industry Appl Occup Environ Hyg 14 449 58 Novembr 14 2014