dc.description.abstract | Little is known regarding levels and source
strength of carbonaceous aerosols in Scandinavia. In the
present study, ambient aerosol (PM10 and PM2.5) concentrations
of elemental carbon (EC), organic carbon (OC), waterinsoluble
organic carbon (WINSOC), and water-soluble organic
carbon (WSOC) are reported for a curbside site, an urban
background site, and a suburban site in Norway in order
to investigate their spatial and seasonal variations. Aerosol
filter samples were collected using tandem filter sampling
to correct for the positive sampling artefact introduced by
volatile and semivolatile OC. Analyses were performed using
the thermal optical transmission (TOT) instrument from
Sunset Lab Inc., which corrects for charring during analysis.
Finally, we estimated the relative contribution of OC from
wood burning based on the samples content of levoglucosan.
Levels of EC varied by more than one order of magnitude
between sites, likely due to the higher impact of vehicular
traffic at the curbside and the urban background sites. In
winter, the level of particulate organic carbon (OCp) at the
suburban site was equal to (for PM10) or even higher (for
PM2.5) than the levels observed at the curbside and the urban
background sites. This finding was attributed to the impact
of residential wood burning at the suburban site in winter,
which was confirmed by a high mean concentration of levoglucosan
(407 ngm−3). This finding indicates that exposure
to primary combustion derived OCp could be equally
high in residential areas as in a city center. It is demonstrated
that OCp from wood burning (OCwood) accounted for
almost all OCp at the suburban site in winter, allowing a new
estimate of the ratio TCp/levoglucosan for both PM10 and
PM2.5. Particulate carbonaceous material (PCM=Organic
matter+Elemental matter) accounted for 46–83% of PM10 at
the sites studied, thus being the major fraction. | nb_NO |