Objectives: to evaluate whether exposure to an urban waste incinerator plant operating in Arezzo (Tuscany Region, Central Italy) since the 2000 is associated with mortality and morbidity.
Design: a population-based cohort study of inhabitants living close to the incinerator in the period 2001-2010 was conducted. The individual exposure histories to the incinerator and other sources in the area were estimated using a dispersion model producing PM10 concentration maps for each source (ADMS-URBAN model). Hazard Ratios (HR) with 95% Confidence Interval (95%CI) adjusted for the other environmental exposures, age and socioeconomic status were estimated for the highest class of exposure using the lowest one as reference. Trends of HR were evaluated too.
Main outcome measures: mortality and hospitalization causes with induction-latent period overlapping the incinerator activity period were analysed.
Results: morbidity analysis showed an increased risk for cardiovascular diseases (No. 732; HR: 1.18; 95%CI 1.06-1.32; trend of HR: 1.08, p=0.006) and a trend of HRs for urinary diseases (trend: 1.13; p=0.063). Mortality analysis showed a trend of HRs for general mortality in males (trend: 1.10; p=0.014), for cardiovascular diseases in males (trend: 1.15; p=0.036), for respiratory diseases in females (trend: 1.30; p=0.098), and an excess of acute respiratory diseases in females with the highest exposure (No. 11; HR=2.54; 95%CI 0.84-7.68).
Conclusions: the cohort study allowed to characterise the environmental exposures considering the most relevant pollution sources and providing estimation of individual environmental exposures. Residual confounding due to the overlapping of concentration maps cannot be excluded and further investigations are needed. However, the increased risks for cardiovascular and respiratory diseases reinforce the limited epidemiological evidence on health effects of incinerators.