We investigated the association between daily emergency ambulance calls (EAC) for elevated blood pressure that occurred during the time intervals of 8:00-13:59, 14:00-21:59, and 22:00-7:59, and exposure to CO, PM10, and ozone. We used Poisson regression to explore the association between the risk of EAC and short-term variation of pollutants, adjusting for seasonality and weather variables. Before noon, the risk was associated with an interquartile range (IQR) (7.9 μg/m3) increase in PM10 at lag 2-4 days below the median (RR = 1.08, p = 0.031) and with an IQR (0.146 mg/m3) increase in CO at lag 6-7 below the median (RR = 1.05, p = 0.028). During 14:00-21:59, the risk was associated with an IQR (18.8 μg/m3) increase in PM10 on the previous day below the median (RR = 1.04, p = 0.031). At night, EAC were negatively affected by lower O3 (lag 0-2) below the median (per IQR decrease RR = 1.10, p = 0.018) and a higher PM10 at lag 0-1 above the median for the elderly (RR = 1.07, p = 0.030).
Keywords: Carbon monoxide; emergency ambulance calls; exacerbation of essential arterial hypertension; ozone; particulate matter.