The present study was aimed at determining airborne concentrations of PAHs, Nitro-/Oxy-PAHs and elements in industrial and urban areas of Taranto, a site of environmental risk in Southern Italy, after the issue of strategic measures for air pollution mitigation and control by the Italian Environment Ministry in 2012. A PM2.5 sampling campaign was carried out from 9 to 28 December 2014 at eight receptor sites, two placed in the urban settlement and five included in the high spatial resolution fence monitoring network of the biggest European steel plant. The integration of collected data with meteorological parameters and source apportionment analysis by Positive Matrix Factorization and bivariate polar plots allowed to discriminate among emission sources and estimate their contributions. Evidence on the effect of distinct processes (homogenization, sintering) occurring inside the steel plant on airborne concentrations of PAHs and selected elements was provided. The impact of emissions from the steel plant “core” on the surrounding area was observed at receptor sites downwind to it. Moreover, the extent of the effectiveness of mitigation measures, partially applied at the moment of study’s beginning, was demonstrated by mean and peak pollutant concentrations at all receptor sites up to one order of magnitude lower than those documented prior to 2012.

SARS-CoV-2 is expected to cause metabolic alterations due to viral replication and the host immune response resulting in increase of cytokine secretion and cytolytic activity. The present prospective observational study is addressed at exploring the potentialities of breath analysis in discrimination between patients with a documented previous history of symptomatic SARS-CoV-2 infection and, at the moment of the enrollment, exhibiting a negative nasopharyngeal swab and acquired immunity (post-COVID) and healthy subjects with no evidence of previous SARS-CoV-2 infection (no-COVID). The main purpose is to understand if traces of metabolic alterations induced during the acute phase of the infection are still detectable after negativization, in the form of a characteristic VOCs pattern. An overall number of 60 volunteers aged between 25 and 70 years were enrolled in the study (post-COVID: n.30; no-COVID: n. 30), according to well-determined criteria. Breath and ambient air samples were collected by means of an automated sampling system (Mistral) and analyzed by Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC/MS). Statistical tests (Wilcoxon/Kruskal-Wallis test) and multivariate data analysis (Principal Component Analysis, Linear Discriminant Analysis) were performed on data sets. Among all compounds detected (76 VOCs in 90% of breath samples), 5 VOCs (1-propanol, isopropanol, 2-(2-butoxyethoxy)ethanol, propanal and 4-(1,1-dimethylpropyl)phenol) showed abundances in breath samples collected from post-COVID subjects significantly different with respect to those collected from no-COVID group (Wilcoxon/Kruskal-Wallis test, p-values < 0.05). Although not completely satisfactory separation between the groups was obtained, variables showing significant differences between the two groups and higher loadings for PCA are recognized biomarkers of COVID-19, according to previous studies in literature. Therefore, based on the outcomes obtained, traces of metabolic alterations induced by SARS-CoV-2 infection are still detectable after negativization. This evidence raises questions about the eligibility of post-COVID subjects in observational studies addressed at the detection of COVID-19. (Ethical Committee Registration number: 120/AG/11).