Fig. 3
Distribution pattern of mean concentrations PM10-2.5, PM2.5–1, and PM1 after 4.5 min and 10 min. Notes: PM was generated by smoking cigarettes in a compact car. PM: Particulate matter. Condition 1 (C1): All windows closed, and the car ventilation turned off. Condition 2 (C2): All windows closed, and the car ventilation turned on power level 2/4, with air directed towards the windshield. Condition 3 (C3): All windows closed, and the car ventilation turned on power level 2/4, with the air directed towards the windshield and feet. Condition 4 (C4): All windows closed, and the car ventilation turned on power level 2/4, with the air directed towards body and head