Commuting and health: the definition of 'risk areas', mobility patterns of population and epidemiological cohort studies - The case of Gela

“Risk areas” define territories where the presence of large industrial plants have an important impact on the environment and may be harmful to human health. This paper focuses on the role of mobility analysis in territorial studies, investigating in particular: (a) its importance for the definition of the territorial boundaries of “risk areas”; (b) its relevance for epidemiological investigations, in terms of improving the definition of groups of exposed populations. After having briefly discussed the reasons why mobility should be carefully considered when determining “risk areas” (section 2), we will turn to the analysis of commuting in the risk area of Gela (Sicily) in order to improve results of the epidemiological cohort study on petrochemical workers conducted by Pasetto et al. (2008). Section 3 shortly reviews gravitational models, while sections 4 and 5 present estimates of a distance-decay function used to identify a cut-off point for commuting to Gela. Sections 6-8 combine the results of mobility analysis with the epidemiological study, confirming the existence of an increased risk for lung cancer mortality due to residence in Gela. Finally, section 9 summarizes the results and points out some of the limits of our analysis, suggesting future possible developments lines of research.