Characterizing air quality in different urban sites: tunnel and school

A survey of measurements has being performed to characterize air pollutants in different urban scenarios: a tunnel crossing a highway with dense traffic flow and a school at 500 m far from it, both in the city, for more than two years. The aim of the study has been the assessment of the variability of air pollutants as a function of the season, daily time-frame and working periods in the two sites, being these patterns closely related to human habits, e.g., vehicle and heating systems use. In this work we present the huge deployment of conventional means utilized and also two systems developed at CEAM that integrate small low-cost sensors. Its use as a monitoring tool in air quality characterization is given. Nitrogen oxides (NOx), ozone (O3 ), ammonia (NH3 ), sulphuric dioxide (SO2 ) and a number of volatile organic compounds (VOCs) have