Indoor and outdoor VOCs and PAHs in schools and houses of Rome, Italy

In the frame of the Life+ EXPAH project, both volatile (VOC) and polynuclear aromatic (PAH) hydrocarbons were monitored during winter 2011-12 and spring/summer 2012 in schools, homes and an office in Rome, Italy. Diffusive sampling, solvent extraction and GC-FID analysis were adopted for VOCs; our concern was focused on aromatic compounds (BTEX, namely benzene and C1-C2 derivatives). As for PAHs, fine particulates were collected daily at low-volume conditions, gathered into weekly pools, extracted with organic solvents and analysed through GC-MSD. Indoor concentrations were compared to the corresponding outdoor values and also to data collected by the ARPA Lazio Agency at stations belonging to regional Air Pollution Control Network. In addition, nitrogen dioxide, ozone and fine particulate (PM2.5) were measured. As for BTEX, indoor concentrations were comparable to those detected outdoors, with some exceptions due to use of solvent-containing products and/or tobacco smoking. The percent composition of BTEX changed site to site but benzene concentrations remained, on the average, lower than at rush traffic stations and below the limit of 5 µg/m3. Among PAHs eleven congeners, namely seven recognized carcinogenic, two mutagenic and two complementary ones were characterized in particulates. The degree of indoor and outdoor pollution looked comparable and the composition of PAH fraction was similar. The concentrations of PM2.5 detected indoors often exceeded even the limit established for PM10. Thus, the population segments most prone to undergo the effects of toxicants (i.e., children and elderly) are specially exposed to pollutants, overall in winter months. Besides that, the VOC and PAH burdens in the air of true life sides (and population exposition) can sensibly differ from those recorded at the regional network stations.