A pilot study from Basel (summer of 2014) showed that air pollution concentrations measured at the level of the 1st or 2nd floor may be around 30% lower than those on the ground in some streets. So far, differences in air pollution levels depending on the floor of residence are poorly understood and hardly characterized. Our indoor environment is strongly affected by ambient outdoor concentrations of air pollutants and therefore a concentration contrast of this magnitude would mean a substantial difference in air pollution exposure for people living at higher floors.
Our project is designed to address this gap in knowledge for four key air pollutants, both in real-time (Particle Number Concentration (PNC), PM2.5 and black carbon) and on the long-term (NO2), and has two components:
1) A real-time (short-term) component which aims to characterize vertical gradients at 10 locations in Basel for 3 air pollutants (PNC, PM2.5 and black carbon) using quality real-time instruments which are sampling simultaneously at 6 different heights between 1 and 25m at each location.
2) A long-term component which aims to characterize the vertical gradient at 20 locations in Basel for NO2, using low-cost passive samplers (PASSAM’s) which are installed for 2 weeks at the homes of volunteering households.
The goal of the project is to understand how the real-time and long-term vertical gradients for four air pollutants depend on the traffic intensity, the configuration of the street and the seasonality.