[SENTIERI: Epidemiological Study of Residents in National Priority Contaminated Sites. Fifth Report].

INTRODUCTION AND OBJECTIVES

This volume provides an update of the health status of the populations living in the National Priority Contaminated Sites (NPCSs) included in the SENTIERI Project. This update is part of an epidemiological surveillance programme carried out in NPCSs, promoted by the Italian Ministry of Health as a further step of a project started in 2006, when the health status of residents in contaminated sites was first addressed within the National Strategic Program "Environment and Health". The Report focuses on five health outcomes: mortality, cancer incidence, hospital discharges, congenital anomalies, and children, adolescents and young adults' health. A key element of SENTIERI project is the a priori evaluation of the epidemiological evidence of a causal association between the considered cause of disease and the exposure. When an a priori evidence is identified, it is given a greater importance in the comment of the study findings.

METHODS

The present update of the SENTIERI Project concerns 45 NPCSs including in all 319 Italian Municipalities (out of over 8,000 Municipalities), with an overall population of 5,900,000 inhabitants at the 2011 Italian Census. Standardized Mortality Ratios (SMRs) and Standardized Hospitalization Ratios (SHRs), referring to a time window of 2006-2013, were computed for all the 45 NPCSs, using as a reference the corresponding mortality and hospitalization rates of the Regions where each NCPS is located. Standardized Incidence Ratios (SIRs) were computed by the Italian Association of Cancer Registries (AIRTUM) for the 22 NPCSs served by a Cancer Registry. AIRTUM covers about 56% of Italy, with partly different time-windows. SIRs have been estimated using as reference population the 4 macroareas in which Italy is divided (North-West, North-East, Centre, South). Prevalence of congenital anomalies was computed for 15 NPCSs.

RESULTS

An all-cause excess of 5,267 and 6,725 deaths was observed, respectively, in men and women; the cancer death excess was of 3,375 in men and 1,910 in women. It was estimated an excess of cancer incidence of 1,220 case in men and 1,425 in women over a five-year time window. With regard to the diseases with an a priori environmental aetiological validity, an excess for malignant mesothelioma, lung, colon, and gastric cancer, and for non-malignant respiratory diseases was observed. Cancer excess mainly affected NPCSs with presence of chemical and petrochemical plants, oil refineries, and dumping hazardous wastes. An excess of non-malignant respiratory disease was also detected in NPCSs in which steel industries and thermoelectric plants were present. An excess of mesothelioma was observed in NPCSs characterized by presence of asbestos and fluoro-edenite; it was also observed where the presence of asbestos was not reported in the legislative national decrees which define the NPCS areas. It is worth noting that, even if the presence of asbestos is not reported in many NPCSs legislative decrees, petrochemical plants and steel industries, for instance, are often characterized by the presence of a large amount of this mineral that, in the past, was extensively used as an insulating material. For the first time, the present Report includes a focus on the health status of children and adolescents (1,160,000 subjects, aged 0-19 years), and young adults (660,000 subjects, aged 20-29 years). Among infants (0-1 year), an excess of 7,000 hospitalizations was observed, 2,000 of which due to conditions of perinatal origin. In the age class 0-14, an excess of 22,000 hospitalizations for all causes was observed; 4,000 of them were due to acute respiratory diseases, and 2,000 to asthma. Data on cancer incidence for subjects aged 0-24 years were derived from general population cancer registries for twenty NPCSs, and from children cancer registries (age group: 0-19 years) for six NPCSs; 666 cases where diagnosed in the age group 0-24 years, corresponding to an excess of 9%. The main contributions to this excess are from soft tissue sarcomas in children (aged 0-14 years), acute myeloid leukaemia in children (aged 0-14 years) and in the age group 0-29 years, non-Hodgkin lymphoma and testicular cancer in young adults (aged 20-29 years). In seven out of 15 NPCSs, an excess prevalence rate of overall congenital anomalies at birth was observed. Congenital anomalies excesses included the following sites: genital organs, heart, limbs, nervous system, digestive system, and urinary system.

CONCLUSIONS

The main findings of SENTIERI Project have been the detection of excesses for the diseases which showed an a priori epidemiological evidence of a causal association with the environmental exposures specific for each considered NPCS. These observations are valuable within public health, because they contribute to priority health promotion activities. Looking ahead, the health benefits of an improved environmental quality might be appreciated in terms of reduction of the occurrence of adverse health effects attributable to each Site major pollutant agents. Due to the methodological approach of the present study, it was not possible to adjust for several confounding factors reported to be risk factors for the studied diseases (e.g., smoking, alcohol consumption, obesity). Even if excesses of mortality, hospitalization, cancer incidence, and prevalence of congenital anomalies were found in several NPCSs, the study design and the multifactorial aetiology of the considered diseases do not permit, for all of them, to draw conclusions in terms of causal links with environmental contamination. Moreover, it must be taken into consideration that economic factors and the availability of health services may also play a relevant role in a diseases outcome. A few observations regarding some methodological limitations of SENTIERI Project should be made. There is not a uniform environmental characterisation of the studied NPCSs in term of quality and detection of the pollutants, because this information is present in different databases which at present are not adequately connected. Moreover, the recognition of a contaminated site as a National Priority Site is based on soil and groundwater pollution, and the available information on air quality is currently sparse and not homogenous. Another limitation, in term of statistical power, is the small population size of many NPCSs and the low frequency of several health outcomes. A special caution must be paid in data interpretation when considering the correspondence between the contaminated areas and the municipality boundaries, as they do not always coincide perfectly: in some cases, a small municipality with a large industrial site, while in other settings only a part of the municipality is exposed to the sources of pollution. Furthermore, all available health information systems are currently accessible at municipality level. The real breakthrough is essentially comprised of the development and fostering of a networking system involving all local health authorities and regional environmental protection agencies operating in the areas under study. The possibility to integrate the geographic approach of SENTIERI Project with a set of ad hoc analytic epidemiological investigations, such as residential cohort studies, case control studies, children health surveys, biomonitoring surveys, and with socioepidemiological studies, might greatly contribute to the identification of health priorities for environmental remediation activities. Finally, as discussed in the last section of the report, there is a need to adopt, in each NPCS, a two-way oriented communication plan involving public health authorities, scientific community, and resident population, taking into account that the history, the cultural frame and the network of relationships specific of each local context play a major role in the risk perception perspective.