Asbestos Emissions from Brake Dynamometer Tests

Asbestos in brakes: Exposure and risk of disease

“…In a study that looked at both brake and clutch repair workers in Knoxville and Knox County Tennessee it was found, that when using the worst asbestos control techniques, that those working up to 7.25 hr per day would reach and exceed the current OSHA standard of 0.1 f/ cc during brake repair. Citing Anderson et al [1973] concentrations of asbestos reached as high as 29 f/cc at distances of 5 feet from the brake drums and 4.8 f/cc at distances as far away as 20 feet. Peak concentrations of asbestos fibers in the breathing zone of brake mechanics were reported to be as high as 15 f/cc when using dry brushing, wet brushing, or compressed air during brake repair and 0.2 f/cm 3 as an 8 hr TWA.…”

“…The authors found a clear dose-response relation between cumulative exposures and pleural mesothelioma and that a significant excess of the mesothelioma was observed at levels that were probably below the limits adopted in most industrial countries [Iwatsubo et al, 1998]. Anderson et al [1973] reports that 58 mesotheliomas were reported among Australian brake mechanics having no other exposures to asbestos and that only a small fraction of the total 82,827 mechanics in Australia worked with brake blocks or brake linings. He concludes that these 58 cases represent 1,062,946 personyears.…”

Asbestos: Rationale Behind A Proposed Air Quality Standard

“…3 -39 " 42 Several investigators have suggested that the asbestos emitted as a result of brake usage is not a significant source of atmospheric asbestos; however, in New York City air asbestos concentrations contiguous to a toll booth were 3 to 5 times background levels. 43 - 44 Additional data are needed before the impact of brake lining decomposition on airborne asbestos levels can be ascertained. asbestos standard should be based on a 30 day average sample and the corresponding maximum allowable asbestos emission rate is 24 g/day.…”

Particulate Matter Associated with Vehicles on the Road. II

“…The wear rate of the asphalt road surface is not known to us, and our observations include no diagnostic species. Available brake-lining wear estimates (Anderson et al, 1973;Cahill and Feeney, 1973) would be inapplicable at the Turnpike tunnels where brakes are seldom applied. A significant contribution from brake linings (-10% Si) (Anderson et al, 1973) would not be supported by the (low) vertical position of Si in Figure 8 or by comparison of brake-lining Mg, Cr, and Ba (Ondov, 1975) with values in Table 2.…”