Cumulative asbestos exposure for US automobile mechanics involved in brake repair (circa 1950s–2000)

Abstract

We analyzed cumulative lifetime exposure to chrysotile asbestos experienced by brake mechanics in the US during the period 1950-2000. Using Monte Carlo methods, cumulative exposures were calculated using the distribution of 8-h time-weighted average exposure concentrations for brake mechanics and the distribution of job tenure data for automobile mechanics. The median estimated cumulative exposures for these mechanics, as predicted by three probabilistic models, ranged from 0.16 to 0.41 fibers per cubic centimeter (f/cm 3 ) year for facilities with no dust-control procedures (1970s), and from 0.010 to 0.012 f/cm 3 year for those employing engineering controls (1980s). Upper-bound (95%) estimates for the 1970s and 1980s were 1.96 to 2.79 and 0.07-0.10 f/cm 3 year, respectively. These estimates for US brake mechanics are consistent with, but generally slightly lower than, those reported for European mechanics. The values are all substantially lower than the cumulative exposure of 4.5 f/cm 3 year associated with occupational exposure to 0.1 f/cm 3 of asbestos for 45 years that is currently permitted under the current occupational exposure limits in the US. Cumulative exposures were usually about 100-to 1,000-fold less than those of other occupational groups with asbestos exposure for similar time periods. The cumulative lifetime exposure estimates presented here, combined with the negative epidemiology data for brake mechanics, could be used to refine the risk assessments for chrysotileexposed populations.

Malignant pleural mesothelioma in US automotive mechanics: Reported vs expected number of cases from 1975 to 2007

“…Several studies have reported airborne asbestos concentrations during automotive repair; some have evaluated short-term, specific tasks, such as opening boxes of asbestos-containing brakes and clutches (Jiang et al, 2008;Madl et al, 2008) or brake grinding (Richter et al, 2009), while others have measured time-weighted average (TWA) asbestos concentrations throughout an entire brake job (Blake et al, 2003;Johnson et al, 1979;Roberts, 1980a,b;Roberts and Zumwalde, 1982;Weir et al, 2001). Using job tenure data for US automotive mechanics, Finley et al (2007) estimated that median cumulative lifetime asbestos exposures ranged from 0.16 to 0.41 fiber/cc-year for facilities with no dust-control procedures (1970s), and from 0.010 to 0.012 fiber/cc-year for those employing engineering controls in the later years (1980s). These estimates are consistent with, but generally slightly lower than, the figures that have been reported for European mechanics (Finley et al, 2007).…”

“…Using job tenure data for US automotive mechanics, Finley et al (2007) estimated that median cumulative lifetime asbestos exposures ranged from 0.16 to 0.41 fiber/cc-year for facilities with no dust-control procedures (1970s), and from 0.010 to 0.012 fiber/cc-year for those employing engineering controls in the later years (1980s). These estimates are consistent with, but generally slightly lower than, the figures that have been reported for European mechanics (Finley et al, 2007).…”

Personal exposure to asbestos and respiratory health of heavy vehicle brake mechanics

“…6 Other studies have concluded that heavy vehicles brake mechanics are exposed to asbestos concentrations in compliance with the US Occupational Safety and Health Administration personal exposure limit (US OSHA PEL) of 0.1 f/cm 3 , and that they are not at excessive risk of developing asbestos-related diseases. [7][8][9][10][11] All these studies were conducted in high-income countries, especially in the United States.…”

Asbestos-Related Diseases in Automobile Mechanics

“…Tel: þ33147107754; fax: þ33147107768; e-mail: jacques.ameille@rpc.aphp.fr of asbestos fibers during brake or clutch repair show disagreement (Rohl et al, 1976;Rodelsperger et al, 1986;Plato et al, 1995;Paustenbach et al, 2003;Finley et al, 2007;Blake et al, 2008;Cohen and Van Orden, 2008;Jiang et al, 2008), contributing to uncertainties about the level of risk of asbestos-related diseases in automobile mechanics.…”

“…In Germany, based on dust measurements in 76 service stations and the occupational histories of 210 vehicle mechanics with an average duration of employment of 21 -10 years, a mean cumulative exposure to asbestos was estimated to be 0.54 -1.1 f ml À1 Â years for car mechanics (Rodelsperger et al, 1986). Finley et al, 2007 recently developed estimates of cumulative chrysotile exposures experienced by automobile mechanics working with brakes and manual clutches. They reported that the 95th percentile and 99th percentile cumulative exposures for vehicles mechanics in the 1970s were 2.0 and 5.7 f ml À1 years, respectively.…”