SENTIERI: Mortalità, incidenza oncologica e ricoveri ospedalieri [Sentieri: mortality, cancer incidence and hospital discharges. Summary].

Summary. The Istituto Superiore di Sanità (National Institute of Health-ISS) has joined forces with a network of Italian scientific institutions operating on a national and regional level and with the WHO European Centre for Environment and Health to develop the SENTIERI Project (Epidemiological Study of Residents in National Priority Contaminated Sites). The objectives, methods and initial results of this study were published in 2010 and 2011 in Epidemiologia & Prevenzione. In the course of 2013, some of the SENTIERI Project findings were published in international scientific journals, and the «SENTIERI approach» was among those sanctioned by the World Health Organization to conduct an initial description of the health status of residents of contaminated sites. This Supplement provides – for each of the 18 National Priority Contaminated Sites (NPCSs) included in the SENTIERI project where the Italian Network of Cancer Registries (AIRTUM) is active – a mortality update to 2010, an investigation of cancer incidence between 1996 and 2005 (in 17 sites) and an analysis of hospital discharges from 2005 to 2010. A commentary explaining methodology and approach is also included, as are remarks on the causal association between environmental exposures and investigated health outcomes based on the a priori assessments of the epidemiological evidence; the main implications for public health and scientific research priorities are also presented. The Supplement also puts forward proposals for further study on key public health and scientific research issues. It represents an important step towards SENTIERI’s overall aim of developing a permanent epidemiological surveillance system in Italy’s contaminated sites. The Report focuses on three health outcome – mortality, cancer incidence and hospital discharges – studied using homogenous methods and official data sources, namely the National Institute of Statistics (Istat), AIRTUM and the Health Ministry. Statistical parameters (SMR, Standardized Mortality Ratio; SIR, Standardized Incidence Ratio; SHR, Standardized Hospitalization Ratio) were computed with a 90% confidence interval; all estimators were adjusted for age and socioeconomic status. In most of the 18 NPCSs, a number of different are present, although in some a single pollutant is listed (such as fluoro-edenite in Biancavilla). A priori evidence evaluation of the association between NPCSs environmental exposures and health outcomes, as defined by SENTIERI, can therefore help comment on the health status of residents. There are several cases in which the project’s findings have been consistent with a priori evidence: stomach cancer (both genders, excess cancer incidence) in the Fidenza NPCS; stomach cancer (women, excess mortality, cancer incidence and hospital discharges) in the Laguna di Grado e Marano NPCS; excess hospitalisation from respiratory diseases in Brescia-Caffaro, Milazzo and Terni Papigno NPCSs; excesses for non-Hodgkin lymphomas (incidence in men and hospitalisation in men and women), melanoma (incidence and hospital discharges in both genders) and breast cancer (incidence and hospital discharges, women) in Brescia-Caffaro NPCS. Results relating to single disease that can be traced back to a single agent, such as asbestiform fibres, can be easily analysed. The Biancavilla NPCS (where the fluoro-edenite asbestiform fibre is present) displays excesses of pleural mesothelioma and its proxy, malignant pleural tumours, as does Priolo, where asbestos coexists with other pollutants. Excesses were also recorded in NPCSs hosting harbour areas (such as Trieste, Taranto and Venice) or comprising industrial areas where chemicals (Laguna di Grado e Marano and Priolo NPCSs) or steel are produced (Taranto, Terni, Trieste NPCSs). Increases linked to more than one environmental exposures in industrial sites with multiple and diverse sources prove harder to interpret. This is the case, for example, when it comes to lung cancer and respiratory diseases. There are also more complex cases in which results do not appear consistent in the three databases or by gender (such as lung cancer in Venice, where mortality and hospital discharges have only increased among women). In order to adequately examine these we must consider factors such as the appropriateness of the health outcome showing the increase, taking into account latency and the length of the observation period. Of further interest are results relating to diseases of the urinary tract such as kidney failure in the NPCSs of Basso Bacino del Fiume Chienti, Taranto, Milazzo and Priolo. Overall, the results discussed above are consistent with the previous findings pertaining to mortality for 1995-2002. The present analysis also introduces a new element – the study of cancer incidence and hospital discharges – which, among other things, can tell us a great deal about diseases with high survival rates and non lethal ones. An example of the former is thyroid cancer, which presents excesses in both databases and for both genders in a number of NPCSs (Brescia-Caffaro, Laghi di Mantova, Milazzo, Sassuolo-Scandiano and Taranto). The study of cancer incidence and hospital discharges also showed cancer excesses for melanoma, breast cancer and non-Hodgkin lymphoma in Brescia-Caffaro NPCS where PCBs (Polychlorinated biphenyl) are the site’s main pollutant. PCBs, according to the 2013 evaluation of the International Agency for Research on Cancer, are ascertained human carcinogens for melanoma and probable carcinogens for breast cancer and non-Hodgkin lymphoma. The conclusions of this study on the health impact of contaminated sites can also be summarised in order to identify the general priorities of public health initiatives. The present supplement puts forward, as a possible methodological approach, the risk profile of residents of the 17 NPCSs. According to this analysis, the rankings reveal an overlapping of credibility intervals, evidence that NPCSs are largely homogenous, such that it is not possible to speak of a limited number of cancer excesses or of strongly affected NPCSs. Thus, each of the 17 NPCSs must be examined individually and cannot be graded according to its rank in cancer incidence. Marginal disease rankings highlight the importance of exposure to asbestos among the resident populations of the 17 NPCSs, while the rankings for cancer incidence in individual NPCSs reveal specific excesses as exemplified by the Priolo NPCS. Certain cancer sites such as mesothelioma, liver cancer and pancreatic cancer stand out and demand closer inspection. Data collected concerning some of the NPCSs in the context of the SENTIERI Project are so conclusive that remediation measures can immediately be put in place. This is the case in the Biancavilla and Brescia-Caffaro NPCSs. A similar conclusion can be drawn for complex sites such as Taranto NPCS, where, based on the results of SENTIERI and the whole available information, we can safely conclude that exposure to environmental agents played an important role, allowing us to set in place «Integrated evaluation of environmental and health impact procedures». SENTIERI approach does not allow definitive causal assessments. However, as stated above, the results do provide a topic for further study without getting in the way of initiatives promoting urgent environmental remediation.