Personal particle number concentration measurements lasted between 7.2 and 8.3 h because of limited amount of condensation liquid inside the device.Therefore, all further analyses were performed for this shorter period comprising 474 5 min-intervals. Table 1 shows the description of the air pollutants as well as the ECG parameters. On average personal PM2.5 and particle number concentration values were higher when the partici-pants were not in traffic. This might be partly due to the use of air conditioning in cars. In accordance, PM2.5 concentrations were