Original Title:
Μελέτη της σχέσης εσωτερικής και εξωτερικής συγκέντρωσης PM2.5 και της χημικής σύστασης σε οργανικό άνθρακα (OC), στοιχειακό άνθρακα (EC) και ιόντα, σε διαμέρισμα στο κέντρο της Αθήνας
Summary:
The aim of the study is to examine the indoor/outdoor relationship of PM2.5
mass concentration and chemical composition, in an apartment situated on a
high-traffic street, in central Athens. 24-hour coupled indoor and outdoor
PM2.5 samples were collected on quartz filters using two identical low volume
controlled flow rate samplers. Subsequently, the filters were chemically
analysed for ions and organic/elemental carbon (OC/EC). During the experimental
campaign (21/1-2/2/2011), the house was naturally ventilated.
I/O ratio for mass concentration ranged between 0.48 and 2.85. Indoor PΜ2.5
levels were poorly correlated to the corresponding outdoor concentrations
(R2=0.13) which is indicative of indoor sources. The OC/EC ratio exceeded the
value of 2 in all indoor samples, implying the presence of secondary organic
aerosol. The I/O ratio for 24-h EC concentrations ranged between 0.53 and 0.92.
In addition, there was a good correlation between indoor and outdoor air
(R2=0.88), confirming the lack of an indoor emission source for EC. In
contrast, it was found impact from major indoor sources for OC, such as
smoking. SO42- had a significant contribution to PM2.5. For NO3- and ΝΗ4+, the
I/O ratios were much lower than unity, due to the presence of strong outdoor
sources (intense vehicles circulation).
Keywords:
PM2.5, Organic carbon, Elemental carbon, ions, I/O ratio
