We read with great interest the article by Di Blasi et al., published in the European Journal of Internal Medicine [1]. This well-designed study provides significant evidence on the association between long-term exposure to air pollutants (PM2.5, NO2, and black carbon) and the increased risk of peripheral artery disease (PAD) in a large cohort from Rome, Italy. The authors are to be commended for addressing various individual and area-level confounders in their analyses. However, as the authors themselves acknowledged, the observational nature of the study limits its ability to infer causality between air pollution and PAD.
