Residual fibre lung burden among patients with pleural mesothelioma who have been occupationally exposed to asbestos

OBJECTIVES: to assess the association among malignant pleural mesothelioma (MPM) and lung cancer (LC) among workers who have been exposed to asbestos and have or not have required an anticipated leave from work, a possibility offered by the 1992 law banning asbestos in Italy, in the framework of the health surveillance programmes on going in the Veneto Region (Northern Italy). SETTING AND PARTICIPANTS: a cohort of asbestos workers derived from the rosters of selected factories and alive in 1992, followed from 1992 to 2012.MPM cases have been identified through the Regional Mesothelioma Registry, while LC cases through a link with the Regional Cancer Registry, hospital discharges, and death certificates. Risks related to asbestos exposure were calculated by mixed effects Poisson regression model. RESULTS: the risk of MPM and LC increases at any additional duration of work, up to very high values for long term durations of work for MPM, and up to a three fold increase for LC. Early retirements have been requested by a fraction only in the position of submitting it. CONCLUSION: subjects who have been exposed to asbestos should be the target of a post-occupational surveillance, and further work is suggested to identify subjects at high risk of LC because of smoking habits and more heavy exposure to asbestos, in order to develop programmes for primary and secondary cancer prevention.