Association of size-resolved number concentrations of particulate matter with cardiovascular and respiratory hospital admissions and mortality in Prague, Czech Republic

We analyzed the association of particle number and PM2.5 concentrations with mortality and cardiorespiratory hospital admissions in Prague. Number concentrations of submicron particles in the range of 15–487 nm were measured continuously at a central site in 2006. The particle number concentrations were integrated into four groups with count median diameters of 31 (NC31), 128 (NC128), and 346 nm (NC346). The total number concentration of submicron particles 15–487 nm (NCtot) was also constructed. The studied health outcomes were the daily hospital admissions due to cardiovascular and respiratory diseases and daily cardiovascular and respiratory mortality and the total mortality. The Poisson regression was used for data analysis. The strongest association was found for the accumulation mode particles (NC346) (RR 1.164, 95% CI: 1.052–1.287 for cardiovascular and 1.334, 95% CI: 1.126–1.579 for respiratory admissions for a 7-day moving average for 1000 particles per 1 cm3 increase). Reasonable association bet...