Short-term effects of air pollution and cardiovascular hospitalizations in the Pisan longitudinal study

Air pollution effects on cardiovascular hospitalizations in small urban/suburban areashave been scantly investigated. Such effects were assessed among the participants in the analyticalepidemiological survey carried out in Pisa and Cascina, Tuscany, Italy (2009-2011). Cardiovascularhospitalizations from 1585 subjects were followed up (2011-2015). Daily mean pollutantconcentrations were estimated through random forests at 1 km (particulate matter: PM10, 2011-2015;PM2.5, 2013-2015) and 200 m (PM10, PM2.5, NO2, O3, 2013-2015) resolutions. Exposure effects wereestimated using the case-crossover design and conditional logistic regression (odds ratio--OR--and95% confidence interval--CI--for 10 g/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) at1 km resolution. During the period 2013-2015 (69 hospitalizations), significant effects at lag 0 wereobserved for PM10 (OR = 1.268, CI: 1.085-1.483) and PM2.5 (OR = 1.273, CI: 1.053-1.540) at 1 kmresolution, as well as for PM10 (OR = 1.365, CI: 1.103-1.690), PM2.5 (OR = 1.264, CI: 1.006-1.589) andNO2 (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/respiratorydiseases. Combining analytical and routine epidemiological data with high-resolution pollutantestimates provides new insights on acute cardiovascular effects in the general population and inpotentially susceptible subgroups living in small urban/suburban areas.