engleski

Spatial Distribution of Carbon in Airborne Particulates in Zagreb

The aim of this study was to determine the spatial and temporal distribution of carbon in PM10 particle fraction in the air of Zagreb, Croatia. Samples were collected at three different monitoring sites in the northern residential part, centre, and southern part of Zagreb during the summer and winter of 2011. The monitoring site in the northern residential part, characterised by low to moderate traffic density and households using gas-heating appliances was considered as urban background (IMI), while the monitoring sites in the centre (CENTAR) and southern part of town (SIGET) with high traffic density and households with gas or district heating were characterized as urban traffic monitoring sites. Small-volume air samples (50 m3) of airborne particles were collected on quartz fibre filters (Pallflex Tissuequartz 2500QAT-UP) pre-fired at 900 ºC for three hours. PM10 mass concentrations were determined ravimetrically according to the HRN EN 12341 standard. Organic carbon (OC), elemental carbon (EC), and total carbon (TC, a sum of EC and OC) in PM10 fraction were determined by the thermal-optical transmittance method (TOT), using the Carbon Aerosol Analyzer (Sunset Laboratory Inc.) following a NIOSH-like protocol. Statistical analysis was performed using the STATISTICA 12.0 statistical software. The mass concentrations and mass fractions of EC and OC were compared in PM10 fractions collected in different seasons and at various sampling sites. Lower mass concentrations of PM10 and EC, OC, and TC in PM10 were observed during summer in comparison to the winter monitoring period. Statistically significant spatial and seasonal differences between the urban background and two other urban traffic monitoring sites were also observed.

EC; OC; OC/EC ratio; PM10; TOT method

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