Short-Term Effects of Air Pollution on Cardiovascular Hospitalizations in the Pisan Longitudinal Study

Air pollution effects on cardiovascular hospitalizations in small urban/suburban areas have been scantly investigated. Such effects were assessed among the participants in the analytical epidemiological survey carried out in Pisa and Cascina, Tuscany, Italy (2009-2011). Cardiovascular hospitalizations from 1585 subjects were followed up (2011-2015). Daily mean pollutant concentrations were estimated through random forests at 1 km (particulate matter: PM₁₀, 2011-2015; PM_2.5, 2013-2015) and 200 m (PM₁₀, PM_2.5, NO₂, O₃, 2013-2015) resolutions. Exposure effects were estimated using the case-crossover design and conditional logistic regression (odds ratio-OR-and 95% confidence interval-CI-for 10 μg/m³ increase; lag 0-6). During the period 2011-2015 (137 hospitalizations), a significant effect at lag 0 was observed for PM₁₀ (OR = 1.137, CI: 1.023-1.264) at 1 km resolution. During the period 2013-2015 (69 hospitalizations), significant effects at lag 0 were observed for PM₁₀ (OR = 1.268, CI: 1.085-1.483) and PM_2.5 (OR = 1.273, CI: 1.053-1.540) at 1 km resolution, as well as for PM₁₀ (OR = 1.365, CI: 1.103-1.690), PM_2.5 (OR = 1.264, CI: 1.006-1.589) and NO₂ (OR = 1.477, CI: 1.058-2.061) at 200 m resolution; significant effects were observed up to lag 2. Larger ORs were observed in males and in subjects reporting pre-existent cardiovascular/respiratory diseases. Combining analytical and routine epidemiological data with high-resolution pollutant estimates provides new insights on acute cardiovascular effects in the general population and in potentially susceptible subgroups living in small urban/suburban areas.