Emerging contaminants in the atmosphere: Analysis, occurrence and future challenges

The presence of emerging contaminants (EC) in the atmospheric environment of urban, rural or even remote areas has become a significant issue for environmental science. This has resulted in the publication in the scientific literature of several works about the analysis, presence and distribution of these compounds in the atmosphere. This work covers the current state of art about EC in the atmospheric compartment, including flame-retardants, perfluoroalkyl substances, surfactants, personal care products, pharmaceutical compounds and licit and illicit drugs. The first part presents an updated overview on the analytical methodologies used to identify and quantify trace levels of these chemicals in outdoor air (passive and active sampling techniques, sample treatment and determination) and the current state of contamination by EC, both gas fraction and atmospheric particle matter. The second part is focused on the use of tree leaves as biosamplers of EC in the atmosphere as an available and affordable tool to assess the exposure to these compounds. The analytical method applied to determine the levels of EC in leaves, the different tree species used as passive samplers (pine needles, gingko, eucalyptus, populus, quercus, bitter orange, etc.) and the distribution of EC worldwide in these particular matrices are discussed.