Psychotropic substances in the air of Italian cities ten years later: The chemical trace of (ab)use behaviours

Abstract

Psychotropic substances (PSs) affect the air of cities, tracing the consumption habits of people. Two extensive seasonal campaigns were performed in Italy (36 sites) between 2018 and 2019, aimed at characterizing PSs in airborne particulate matter (PM) at the same locations investigated in 2009, improving the knowledge of relationships linking PSs with source-related air contaminants, and possibly pointing out the changes of the (ab)use prevalence in the country. To reach a more comprehensive picture of the environmental pollution contour, other contaminants including n-alkanes, polycyclic aromatic hydrocarbons (PAHs) and phthalates were investigated together with PSs. The occurrence of both licit and illicit drugs was confirmed in the air at concentration levels ranging from a few pg/m3 (overall cocaine and cannabinoids in the summer outside of big cities) to some ng/m3 (illicit drugs during winter in the city centers and caffeine), and up to tens of ng/m3 (nicotine during the winter). The PS concentration trends observed in the cities were distinct from those of total n-alkanes, PAHs and PM. Meanwhile, the concentration values of illicit substances seemed linked to prevalence rates along Italy, though quantitative relationships haven't been assessed yet neither in neat values, nor as concentration ratios vs. nicotine and PM. Furthermore, the trends of illicit PSs looked coherent with the prevalence rates recorded in the Rome metropolitan area from 2009 to 2013 and in 2019.