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The airborne route of transmission of SARS-CoV-2 was confirmed by the World Health Organization in April 2021. There is an urge to establish standardized protocols for assessing the concentration of SARS-CoV-2 RNA in air samples to support risk assessment, especially in indoor environments. Debates on the airborne transmission route of SARS-CoV-2 have been complicated because, among the studies testing the presence of the virus in the air, the percentage of positive samples has often been very low. In the present study, we report preliminary results on a study for the evaluation of parameters that can influence SARS-CoV-2 RNA recovery from quartz fiber filters spotted either by standard single-stranded SARS-CoV-2 RNA or by inactivated SARS-CoV-2 virions. The analytes were spiked on filters and underwent an active or passive sampling; then, they were preserved at −80 °C for different numbers of days (0 to 54) before extraction and analysis. We found a mean recovery of 2.43%, except for the sample not preserved (0 days) that showed a recovery of 13.51%. We found a relationship between the number of days and the recovery percentage. The results presented show a possible issue that relates to the quartz matrix and SARS-CoV-2 RNA recovery. The results are in accordance with the already published studies that described similar methods for SARS-CoV-2 RNA field sampling and that reported non-detectable concentrations of RNA. These outcomes could be false negatives due to sample preservation conditions. Thus, until further investigation, we suggest, as possible alternatives, to keep the filters: (i) in a sealed container for preservation at 4 °C; and (ii) in a viral transport medium for preservation at a temperature below 0 °C.

In this study, data on the hourly concentrations of the total particle-bound Polycyclic Aromatic Hydrocarbons (p-PAHs) collected between 1 August 2013 and 31 August 2014 by the air quality fence monitoring network of the biggest European steel plant, were analyzed. In contrast with what was predicted, the total p-PAH concentration did not decrease with distance from the steel plant, and higher concentrations were registered at the Orsini site, in the urban settlement, relative to the Parchi site, which is nearest to the coke ovens. Therefore, in order to identify and explain the cause of these high concentrations, a tailored monitoring experiment was carried out on a specific monitoring pathway by using a total p-PAHs monitor placed onto a cart. The real-time monitoring of the total p-PAH concentration on the road revealed to be a useful tool, which identified vehicular traffic as an important source of p-PAHs and highlighted the possible high short-term effect that vehicular traffic sources could have on the health of the exposed human population. Moreover, the study focused attention on the importance of the spatial representativeness of fixed monitoring stations, especially in a highly complex industrial area such as Taranto (Southern Italy).

The present study focused on the determination of benzene, toluene, ethylbenzene and xylenes (BTEX) concentration levels in 97 refill liquids for e-cigs selected by the Italian National Institute of Health as representative of the EU market between 2013 and 2015 prior to the implementation of the European Union (EU) Tobacco Product Directive (TPD). Most of the e-liquids investigated (85/97) were affected by BTEX contamination, with few exceptions observed (levels below the limit of quantification (LOQ) of headspace-solid phase micro extraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) methodology). Across brands, concentration levels ranged from 2.7 to 30,200.0 µg/L for benzene, from 1.9 to 447.8 µg/L for ethylbenzene, from 1.9 to 1,648.4 µg/L for toluene and from 1.7 to 574.2 µg/L for m,p,o-xylenes. The variability observed in BTEX levels is likely to be related to the variability in contamination level of both propylene glycol and glycerol and flavoring additives included. No correlation was found with nicotine content. Moreover, on a limited number of e-liquids, gas chromatography-mass spectrometry-olfactometry (GC-MS-O) analysis was performed, allowing the identification of key flavoring additives responsible of specific flavor notes. Among them, diacetyl is a flavoring additive of concern for potential toxicity when directly inhaled into human airways. The data reported are eligible to be included in the pre-TPD database and may represent a reference for the ongoing evaluation on e-liquids safety and quality under the current EU Legislation.