[Mesothelioma incidence decreases parallel to asbestos exposure decrement or interruption: a confirmation of a dose-response relationship, with implications in public health].

On the basis of the available evidence, several groups of experts and investigators identified a dose-response relationship between exposure to commercial types of asbestos fibres and mesothelioma risk. The first mathematical model was proposed by Peto et al. It was derived from a conceptualisation of the multistage theory of cancer and provides an interpretation of the risk for the occurrence of mesothelioma in cohorts of exposed workers. In the study described in this paper, the author reviewed the data suggesting a decrease in mesotheliomas rate follosing reduction or interruption of exposure. Descriptive analyses and the few available long-term cohort studies indicate a decrease in risk. This is supported also by the fact that even the most biopersistent asbestos fibres are eliminated from the lungs. Indeed, a slow but effective reduction of risk has been demonstrated in the cohort of Wittenoom workers in Australia, previously exposed to crocidolite.