Work-related cancers most often develop after very long latency periods. This is the case with cancers linked to asbestos exposure, most of which develop several decades after exposure to this hazard began, by which time individuals are no longer receiving any medical monitoring related to their occupational exposure. This is why, in 1995, regulations allowed workers who had been exposed to a carcinogen during their working lives to receive medical monitoring covered by the Primary Health Insurance Fund (CPAM) (Article D 461-25 of the Social Security Code). The ESPACES project proposes and evaluates a method for actively identifying retirees who may have been occupationally exposed to asbestos in order to inform them of their rights to post-occupational medical monitoring and to assist them with the necessary procedures. This study was conducted at the Health Examination Centers (CES) of six pilot CPAMs (Côtes d'Armor, Haut-Rhin, Loiret, Nord, Paris, Vienne). A sample of 6,000 retirees from the years 1994, 1995, and 1996 was randomly selected. These retirees received a mail-in questionnaire asking them to trace their employment history, and 60% of them responded. These career histories were cross-referenced with data from a job-specific asbestos exposure matrix to determine, for each individual, the probability of having been exposed to this hazard during their working life. Of the 3,367 careers analyzed, 68% had a probability of having been exposed to asbestos during at least one occupational episode, regardless of its duration. When the probability of exposure for each study participant is taken into account, the proportion of exposed individuals is 27.6%. This figure is entirely comparable to estimates made by other research teams based on different populations. Screening using the matrix inevitably leads to classification errors due to the unique characteristics of each individual; which is why an individual validation step for the results is essential. The CES physicians therefore invited retirees presumed to have been exposed to a medical interview to verify the matrix results. Following these interviews, the 483 retirees whose exposure was confirmed by the physicians were referred to their CPAM to initiate procedures for post-occupational medical follow-up; the application was accepted for 159 of them, 52 were denied, and 105 applications are still pending. An evaluation of the results obtained by comparison with a control sample of CPAMs already shows that the tested procedure increases the number of cases covered by a factor of 17. Currently, only large national companies and the asbestos processing sectors have established formalized systems for informing their retirees, whereas the highest proportion of exposed individuals is found in a wide range of economic sectors, such as metallurgy, construction, services, machinery manufacturing, and automotive mechanics. This is why a widespread implementation of the procedure would reduce information disparities among people who have been exposed to asbestos. To minimize the number of individuals screened incorrectly and to propose a realistic procedure with a view to widespread implementation, the performance of an index accounting for the probability and duration of exposure was analyzed. Screening could be limited to individuals aware of their asbestos exposure and those whose index is greater than or equal to a threshold to be defined. Several simulations were conducted: they allow for the definition of a perfectly reasonable threshold, both in terms of ethics (minimizing false positives and false negatives) and feasibility for the CES: the proportion of retirees invited each year for a medical consultation would represent 3% of the clinical activity of the 70 occupational health services (13,000 consultations) for a benefit of 7,000 cases managed. The field of occupational health is covered by legitimate stakeholders, notably occupational physicians and the Occupational Health Inspection. For a program of this scale to be implemented, it is essential that these various partners cooperate and be involved in the entire screening process for exposed retirees. Finally, this program requires the establishment of the resources necessary for its success. If successful, this initiative could be expanded to include post-occupational monitoring of retirees and other categories of non-working individuals who were exposed during their working lives to carcinogens other than asbestos, thereby enabling a more equitable approach to post-occupational medical follow-up. (R.A.)