"Indoor air quality at life and work environments in Rome, Italy".

The air quality of three different microenvironments (school, dwelling and coffee bar) located in the city of Rome, Italy was assessed. Indoor and outdoor concentrations of polycyclic aromatic hydrocarbons (PAHs) associated with PM2.5 particles were determined during an intensive three-week sampling campaign conducted in March 2013. In interiors total particulate PAHs ranged from 1.53 to 4.96 ng/m3 while outdoor air contained from 2.75 to 3.48 ng/m3. In addition gaseous toxicants, i.e. NO2, NOX, SO2, O3 and BTEX (benzene, toluene, ethyl-benzene and xylene isomers) were determined both in internal and external air. To solve the origin of indoor and outdoor PAHs, several source apportionment methods were applied. Multivariate analysis revealed that emissions from motor vehicles, biomass burning for heating purposes and soil re-suspension were the major sources of PAHs in the city. No linear correlation was established between indoor and outdoor values for PM2.5 and BTEX; the respective indoor/outdoor concentration ratios exceed unity except for PM2.5 in the no smoking home and benzene in all school floors. This suggests that important internal sources such as tobacco smoking, cleaning products and re-suspension dust contributed to indoor pollution. Using the monitoring stations of ARPA Lazio regional network as reference, the percentage within PAH group of benzo[a]pyrene, which is the WHO marker for the carcinogenic risk estimates, was ca. 50% higher in all locations investigated.