[SENTIERI - Epidemiological Study of Residents in National Priority Contaminated Sites. Sixth Report].

INTRODUCTION ADN OBJECTIVES

The Sixth Report presents the results of the "SENTIERI Project: implementation of the permanent epidemiological surveillance system of populations residing in Italian Sites of Remediation Interest", promoted and financed by the Italian Ministry of Health (Centre for Disease Control and Prevention - CCM Project 2018). The aim of this study is to update the mortality and hospitalization analyses concerning the 6,227,531 inhabitants (10.4% of the Italian population) residing in 46 contaminated sites (39 of national interest and 7 of regional interest). The sites include 316 municipalities distributed as follows: 15 in the North-East (20.3% of the investigated population); 104 in the North-West (12% of the investigated population), 32 in the Centre (12.6% of the investigated population), 165 in the South and Islands (55.5% of the investigated population). Analyses were carried out on the paediatric-adolescent (1,128,396 residents) and youth (665,284 residents) population, and a study on congenital anomalies (CA) was carried out at sites covered by congenital malformation registers. Accompanying the epidemiological assessments, site-specific socioeconomic conditions were examined and an overall estimate of excess risk for populations residing at contaminated sites was drawn up. By means of a systematic review of the scientific literature, the epidemiological evidence on causal links between sources of environmental exposure and health effects was updated to identify pathologies of a priori interest.

METHODOLOGY

In the 46 sites included in the SENTIERI Project, mortality (time window: 2013-2017) and hospital admissions (time window: 2014-2018) of the general population of all ages, divided by gender, and of the paediatric-adolescent (0-1 year, 0-14 years, 0-19 years), youth (20-29 years), and overall (0-29 years) age groups, divided by gender, were analysed. In 21 sites, CA diagnosed within the first year of life were studied. Standardised mortality ratios (SMR) and hospitalization ratios (SHR) were calculated with reference to the rates in the regions to which the sites belong. The reference population was calculated net of residents in the sites. CA were studied by calculating the prevalence per 10,000 births and the ratio, multiplied by 100, between the cases observed at the site and those expected on the basis of the prevalences observed in the reference area (region or sub-regional area of belonging, according to the geographical coverage of the registry). The socioeconomic condition studied in the 46 sites is based on the convergence of three deprivation indicators with respect to the reference region: deprivation index at municipal level, deprivation index at census section level, premature mortality indicator (age range 30-69 years) for chronic non-communicable diseases. For the estimation of excess risk for the entire study population, meta-analysis of the mortality and hospitalization risk estimates for each site was carried out and the number of excess deaths estimated for the sites as a whole. The epidemiological evidence was updated through a systematic literature review (January 2009-May 2020), following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The search was carried out on the search engines MEDLINE, EMBASE and Web of Science; the quality of the studies included in the review was assessed using the AMSTAR 2 checklist for systematic reviews and the NewCastle-Ottawa Scale for observational studies in the case of cohort and case-control studies and a modified version thereof for ecological and cross-sectional studies. The update was based on the selection of 14 systematic reviews, 15 primary studies, 6 monographs/reports from international scientific organisations on health effects due to the presence of environmental exposure sources.

RESULTS

Mortality. The a priori causes of interest that occur most frequently in excess are, in descending order: malignant lung cancer, malignant mesothelioma of the pleura, malignant bladder cancer, respiratory diseases, non-Hodgkin lymphomas, malignant liver cancer, all malignant tumours, malignant colorectal cancer, malignant stomach cancer, total mesotheliomas, malignant breast cancer, and asbestosis. Hospitalization. The a priori causes of interest that occur most frequently in excess are represented in descending order by: respiratory diseases, malignant lung cancer, malignant tumours of the pleura, malignant bladder cancer, malignant breast cancer, malignant liver cancer, asthma, malignant colorectal cancer, all malignant tumours, malignant stomach cancer, non-Hodgkin's lymphomas, acute respiratory diseases, leukaemias. The differences observed between mortality and hospitalization can be attributed to the intrinsic characteristics of the diseases (higher or lower lethality, gender differences in incidence), lifestyles, and occupational phenomena. Age classes. Excesses of general mortality were observed in the first year of life at the Manfredonia, Basso Bacino Fiume Chienti, Litorale Domizio Flegreo and Agro Aversano sites; in the 0-1 year and 0-19 year age groups at Casale Monferrato; in the paediatric age group at Serravalle Scrivia and at the Trento Nord site; in the 0-19 year age group at Sassuolo Scandiano; in the young age group (0-29 years) at the two municipalities of Cerchiara and Cassano (Crotone-Cassano-Cerchiara site). With regard to hospitalization due to natural causes, risk excesses in both genders are found in the first year of life in 35% of the sites (Porto Torres industrial areas, Bari-Fibronit, Basso bacino fiume Chienti, Bolzano, Crotone-Cassano-Cerchiara, Cerro al Lambro, Bologna ETR large repair workshop, Gela, Manfredonia, Massa Carrara, Pioltello Rodano, Pitelli, Priolo, Sesto San Giovanni, Trento Nord, and Trieste). These same sites, with the addition of Casale Monferrato, Cengio e Saliceto, Serravalle Scrivia, and Sulcis-Iglesiente-Guspinese (total: 43% of sites), show excesses for all natural causes, in both genders, even in the paediatric-adolescent age group (0-19 years). Among young adults (20-29 years), the analyses show excesses of hospitalization for all natural causes in both genders in the Bolzano, Crotone-Cassano-Cerchiara, Gela, Manfredonia, Pitelli, Priolo, and Sulcis-Iglesiente-Guspinese sites. Among young women only, excesses for all natural causes are also found in Brescia Caffaro, Brindisi, Broni, Casale Monferrato, Crotone-Cassano-Cerchiara, Falconara Marittima, Fidenza, and Massa Carrara. Congenital anomalies. In the 21 sites investigated for CA, 10,126 cases of CA, validated by participating registers, were analysed out of 304,620 resident births. Genital CA is the subgroup for which the greatest number of excesses was observed (in 6 out of 21 sites). The available evidence does not allow a causal link to be established between the excesses observed for specific subgroups of ACs and exposure to industrial sources, but the results suggest further action. The interpretation of the results appears, in fact, particularly complex as the scientific literature on the association between exposure to industrial sources and AC is very limited. Socioeconomic status. The sites in which the indicators converge to show the presence of fragility are: Litorale Vesuviano area, Val Basento industrial areas, Basso Bacino fiume Chienti, Biancavilla, Crotone-Cassano-Cerchiara, Litorale Domizio Flegreo and Agro Aversano, Livorno, Massa Carrara, Trieste. Global impact. Over the period 2013-2017, an estimated 8,342 excess deaths (CI90% 1,875-14,809) or approximately 1,668 excess cases/year, 4,353 excess deaths among males (CI90% 334-8,372) and 3,989 among females (CI90% -1,122;9,101). The pooled excess risk of general mortality is 2% in both genders (pooled SMR 1.02; CI90% 1.00-1.04). The proportion of excess deaths to total observed deaths is almost constant over time, rising from 2.5% in 1995-2002 to 2.6% in 2013-2017. The number of deaths in absolute value is also very similar between the periods analysed. Deaths from all malignant tumours contribute the most by accounting for 56% of the observed excesses, the excess risk of mortality from malignant tumours across all sites, compared to the reference populations, is 4% in the male population (pooled SMR 1.04; CI90% 1.01-1.06) and 3% among the female population (pooled SMR 1.03; CI90% 1.01-1.05). Hospitalization (2014-2018) in the 46 sites as a whole was in excess of 3% for all causes, in both genders, for all major disease groups (males: SHR pooled 1.03; CI90% 1.01-1.04 - females: SHR pooled 1.03; CI90% 1.01-1.05). The results for the pooled estimates at the 46 sites on the general population, both with regard to mortality and hospitalization, are consistent in indicating excess risk in both genders for all the diseases considered and, in particular, for all malignancies. A total of 1,409 paediatric-adolescent deaths and 999 young adult deaths were observed, and the pooled analysis of mortality across the 46 sites showed no critical issues, with pooled estimates for all causes, perinatal morbid conditions and all malignancies falling short of expectations. The analysis of hospitalizations, on the other hand, showed an excess risk of 8% (males: SHR pooled 1.08; CI90% 1.03-1.13 - females: SHR pooled 1.08; CI90% 1.03-1.14) for all causes in the first year of life, and in paediatric-adolescent and juvenile age of 3-4% among males (age 0-19 years: SHR pooled 1.04; CI90% 1.02-1.06 - age 20-29 years: SHR pooled 1.03; CI90% 1.00-1.05) and 5% among females (in both age groups; SHR pooled 1.05; CI90% 1.02-1.08). The pooled analysis of mortality for the a priori identified diseases reported excesses for specific diseases in the group of sites with sources of exposure associated with them. Mortality from total mesotheliomas is three times higher at sites with asbestos present (males: pooled SMR 3.02; CI90% 2.18-3.87 - females: pooled SMR 3.61; CI90% 2.33-4.88) and that from pleural mesotheliomas more than two times higher at the group of sites with asbestos and port areas (males: pooled SMR 2.47; CI90% 1.94-3.00 - females: pooled SMR 2.43; CI90% 1.67-3.19). Lung cancer was in excess by 6% among males (pooled SMR 1.06; CI90% 1.03-1.10) and 7% among females (pooled SMR 1.07; CI90% 1.00-1.13). In addition, there are excess mortalities for colorectal cancer at sites with chemical plants, by 4 % among males (SMR pooled 1.04; CI90% 1.01-1.08) and 3 % among females (SMR pooled 1.03; CI90% 1.00-1.07) and for bladder cancer among the male population of sites with landfills (+6 %: SMR pooled 1.06; CI90% 1.02-1.11). Among the diseases of a priori interest, stomach and soft tissue cancers are at fault as a cause of death among all the sites considered.

LITERATURE REVIEW

The update of the epidemiological evidence underlying the Sixth SENTIERI Report has highlighted in the general population a possible association, previously undiscovered, between certain diseases and residence near petrochemical and steel plants, landfills, coal mines and asbestos sources.

CONCLUSIONS AND PERSPECTIVES

Despite the fact that this is an ecological study, and the excesses of pathologies with multifactorial aetiology can never be mechanically attributed solely to the environmental pressure factors that exist or existed in the areas studied, the ability to identify the excesses found in the contaminated sites investigated by the SENTIERI Project confirms the validity of this method of assessing the site-specific health profile, based on the use of epidemiological evidence to identify pathologies of interest a priori. In interpreting the data and lending robustness to what has been observed, comparison with the results obtained in previous Reports is essential. The global estimates give an overall picture that shows excess mortality and hospitalization in these populations compared to the rest of the population, and show how, for specific pathologies, comparable effects are produced at sites with similar contamination characteristics. The themes developed in the in-depth chapters broaden the vision and understanding of the complex interactions between environment and health, describe the possibilities offered by new ways of communicating the results, and confirm the modernity of a Project that began way back in 2006, and that could be grafted onto the objectives of the National Recovery and Resilience Plan within the framework of the Operational Programme Health, Environment, Biodiversity and Climate.