Introduction: inflammatory bowel disease (IBD) is a multifactorial pathology with an increasing incidence. There is no study that has assessed a possible relationship with very high residential radon exposure in the study area. The aim of the study was to analyze if residential radon concentration is associated with a higher incidence of IBD.
Material and methods: an ecological study was performed. All incident cases of inflammatory bowel disease in the area of Santiago de Compostela were included between January and December 2017. Radon levels at a municipal level were correlated with demographic factors and type of IBD.
Results: ninety-six patients were included, 63 (65.6 %) with ulcerative colitis, 29 (30.25) with Crohn's disease and four (4.2 %) with indeterminate colitis. The incidence rate per 100,000 inhabitants-year was 21.6 cases. There were no statistically significant differences in the type of disease developed regarding radon levels (p > 0.05). No correlation between radon levels and the cumulative incidence of inflammatory bowel disease at the municipal level was observed (Spearman's rho = 0.13, p-value 0.5).
Conclusion: in the area of Santiago de Compostela, there is a higher incidence of IBD in comparison with previous studies using western countries as reference. However, there was no correlation with the municipal average radon concentration and incidence of IBD or any of its types in this study.