Objective: to identify the most suitable marker for monitoring ETS inside a moving car, and to verify the efficacy of window opening to reduce ETS pollution inside the car.
Design: experimental pilot study. SSETTING AND PARTICIPANTS: monitoring of ETS markers in a moving car.
Main outcomes measures: we used real time analyzers to measure: n particulate matter as mass (mug/m3, PM1, PM2.5, PM10); n suspended particle number (total number of particles sized >0.3 e >0.4 mum; n the number of particles with aerodynamic size between 0.3-0.4 mum in diameter; n total volatile organic compounds (TVOC); n carbon monoxide (CO). The recordings were carried out inside a car moving on the road at the speed of 50 km/h, with controlled conditions of temperature and relative humidity.
Results: after lighting a cigarette, with driver's window closed, the levels of all the pollutants increased dramatically, with peaks of 700 mug/m3 for PM2.5 and PM10, and of over 600,000 particles/ liter, while TVOC reached values up to 6,000 mug/m3 and CO up to 6 ppm. When a cigarette was lit with the window 1/4 open, excess pollution was promptly recorded, although with less intensity. With the window completely open, PM, TVOC and CO concentrations were hardly measurable as compared to background levels. On the contrary, particle number increased dramatically up to over 300,000/liter, mostly due to the submicrometric particle fraction in the range 0.3-0.4 mum.
Conclusion: smoking just a cigarette inside a car represents an extremely high exposure to ETS. Partially opening the window is useless to prevent the accumulation of pollutants. Complete window opening is helpful to remove coarse PM and volatile pollutants, but is ineffective against submicrometer particles. Measuring particle number seems to be the best way to assess ETS pollution inside a car.