In response to a request from public authorities regarding the health impact of exposure to asbestos contained in motor vehicles among the population of automotive mechanics, a quantitative assessment of the risk of developing cancer (lung cancer and pleural mesothelioma) in this population was conducted. To carry out this assessment within the short timeframe allotted, a review of available data was conducted. The population of automotive mechanics was selected using data from the 1999 census (INSEE), by 5-year age group, based on economic activities (NAF) and occupational and social categories (PCS) within the working population. Risk calculations were thus performed for 242,360 men aged 16 to 60 working as automotive mechanics. Mechanics’ asbestos exposure is primarily associated with work on friable components prior to 1997 (disc and drum brakes; clutch linings). The available dust exposure measurements corresponding to work on these components varied widely. No data characterizing the time mechanics spent on these tasks during a workweek existed. Therefore, weekly exposure profiles were simulated based on different levels associated with the tasks and data from the 1994 SUMER survey. The models applied are commonly used by international health authorities to assess the carcinogenic effects of chrysotile. The exposure scenarios incorporated into the calculations combine different task-specific levels with two time periods, different distributions of the proportion of exposed mechanics, and two dates for the phasing out of the vehicle fleet. One of the scenarios explored emerged as the most realistic: it assumes that all mechanics were exposed to asbestos, that this exposure averaged between 0.06 and 0.25 fibers/ml per week for the period prior to 1997 (the date the sale of new vehicles containing asbestos was banned) and between 0.01 and 0.06 for the period from 1998 to 2010. According to this scenario, the number of cancer deaths (lung cancer and mesothelioma) due to asbestos exposure that would occur (over a lifetime) in this population of mechanics would be 604 deaths already "determined" by exposure prior to 2003 and unavoidable, and an additional 42 deaths would occur if no measures were taken to change the condition of the vehicle fleet. (R.A.)