Determinanti geografiche della mortalità per tumore tiroideo nella Sicilia orientale

Abstract

The study of geographic determinants in the processes of spreading infectious diseases has a long tradition. As a result of the increase in the incidence of chronic and non-infectious diseases, such as cancer and various types of heart disease, especially in the more advanced countries, the typical methods of spatial analysis have also been applied to these types of diseases. In fact, their heterogeneous aetiology often includes environmental risk factors that need to be investigated using geographic techniques. The object of this study is the possible influence of an environmental risk factor on the onset of thyroid cancer (TC): volcanic activity. Numerous studies conducted in different parts of the world show that in volcanic areas the incidence of this tumour is significantly higher than the national average. In the present work, we propose an exploratory study of the spatial distribution of TC in Eastern Sicily, where the Mt. Etna is located. Georeferencing the data provided by the Cancer Registry of Eastern Sicily, we will provide a visualization of the phenomenon through geographical maps, highlighting the areas with significantly higher incidence than expected. We will then apply the generalized Ripley’s K-function and the local Moran’s I to verify the presence of high-risk areas, taking into account both the proximity to the volcano and the non-homogeneous distribution of the population over the territory. Our results seem to confirm the consolidated opinion that the presence of a volcano can determine the increase in the incidence of TC.

Keywords

• spatial autocorrelation
• Local Moran’s I
• generalized Ripley’s K-function
• point process