Characterization of organic fraction associated to deposition dust of Salerno University interiors

As hosting students, teachers and researchers and, contemporarily, being sites whose activities often require using chemicals that pose a threat, university premises look important subjects of investigation with regards to interiors' pollution. Despite that, insufficient measurements have been performed until now. Scarce information is still available about the occurrence of organic toxicants, in particular of emerging organic contaminants, whose characterization would allow estimating the relative impact of internal and external sources of health risk. Though health risk has been associated overall to inhalation of toxicants (and therefore to vapours and fine aerosols), nevertheless in interiors contact and ingestion are important. Thus, also dusts settled on surfaces contribute to loss of environmental quality. The characterization of organic compounds associated to settled dusts was performed at two locations (the bar hall and library) of University of Salerno, in the Department of Pharmacy. Contemporarily, dust was collected outdoors. The surfaces (flat, each 0.40 m2, situated 1.5-2.0 m over the ground) were cleaned with pre-washed towels and exposed to air over 30 days; afterwards, settled dusts were collected through wiping accurately with glass wool strips previously baked in oven at 250°C. Dust samples were extracted in ultrasonic bath and fractionated through column chromatography on neutral alumina. Instrumental analyses were carried out in GC-MSD and were focused on n-alkanes, PAHs, phthalates, psychotropic substances and a list of emerging contaminants including parabens, nonylphenol and bisphenol-A. All contaminants were more abundant indoors than outdoor by a factor ranging from ~2 to >100. This seems to indicate that indoors sources were more important that chemical intrusion from outdoors, and/or the lifetime of targeted compounds was longer indoors.