Il mesotelioma pleurico nei lavoratori esposti ad amianto nelle raffinerie di petrolio: Malattia professionale ed evento sentinella

Aim. Before our epidemiological studies, petroleum refinery workers were not considered at risk for asbestos-related pathologies, in spite of the documented presence of asbestos. This article reports these studies, which demonstrate a high risk of pleural mesothelioma and point to the occupational origin of some asbestos-related pathologies among the maintenance staff of the refineries. Materials and methods. Cohort and case-control epidemiological studies, conducted in Liguria and Canada, analysed the subgroup most heavily exposed to asbestos (maintenance staff) and the control groups not exposed (office staff and the general population). Relative risk (RR) and attributable risk (AR) have been estimated also using Poisson regression. Results. Our studies on the maintenance staff have indicated a very high AR for pleural mesothelioma (96-100%) and lung cancer (42-49%), and an excess of mortality due to all neoplastic and non-neoplastic causes. Conclusions. The excess of mesothelioma (sentinel event) has permitted the identification of the group exposed to asbestos (the maintenance staff). The internal comparison has allowed the detection of excess asbestos-related pathologies. The presence of an asbestos risk in refineries is now confirmed at an international level, but there is a tendency to limit the effects of asbestos to mesothelioma only. On the contrary, according to our studies, many other neoplastic and non-neoplastic pathologies should be recognized as occupational diseases. In order to highlight such risks, it is however necessary to use methods which are in accordance with good epidemiological practice, such as the identification of both the subgroup of actually exposed workers and the appropriate reference population.