Reactive Nitrogen Compounds and BTEX in Urban Atmosphere: Interactions, Ozone Formation Potential, Typical Levels and Trends

Air quality in urban centers has received attention worldwide due to high air pollution levels. Inorganic nitrogen compounds and BTEX (benzene, toluene, ethylbenzene and xylenes) have been prominent in urban areas. They participate intensely in various reactions in the atmosphere, forming secondary pollutants. This review includes advances in the understanding of the atmospheric composition when it approaches to recent information on reactions involving specific compounds, as well as ozone formation potential and gas-particulate interactions, discussed in studies found in the literature about the subject. In addition, it discusses emission sources, behavior in the atmosphere, effects on human health, typical levels of atmospheric concentrations and trends. It is also concluded that additional studies are still needed regarding the mechanisms of interaction between chemical species and the effects on population health and the environment, as well as the influence of these compounds on the formation of non-legislated or poorly investigated toxic contaminants.