Fig. 5
Concentration of three particle fractions in μg/m3 on a timescale representing local clock time during experiment 2. The inset shows the simultaneous registration of the concentration of the thoracic fraction (PM-10). (a) Paint booth ventilation turned on at 15:50 h; (b) increased ventilation due to a thunderstorm past over Nijmegen between 18:30 and 19:00 h causing a sudden decrease in dust concentration (see inset); (c) The ventilation system was shut off at 19:00. (d) The ventilation system is turned on at 07:00 h the next morning