(d) April 7: One line source from 100 m to 500 m above ground level (AGL) over Pristina (fuel storage), one over Novi Sad (industrial company)  and one over Sombor (fuel storage). The emission started at April 7, 1.00 UTC and lasted 12 hours.

 

Figure 8.1d: Time integrated concentrations calculated with HYSPLIT_4 modeling system for April 18-20. The stars indicate the geographic position of the sources. A line source is assumed at each location which stretches from 100 to 500 m AGL. The concentrations are given in relative units, corresponding to an emission rate of 1 unit of pollutant per hour.

 

·        April 18–20: One line source from 100 m to 500 m AGL over Pristina and one over Kursumlija. The emission started at April 18, 21 UTC and lasted 12 hours.

 

 

Figure 8.2: Time integrated concentrations calculated with HYSPLIT_4 modeling system for April 18-20. The stars indicate the geographic position of the sources. A line source is assumed at each location which stretches from 100 to 500 m AGL. The concentrations are given in relative units, corresponding to an emission rate of 1 unit of pollutant per hour.

Time-integrated concentrations and depositions resulting from the aforementioned scenarios are shown in figures 8.1a-d and 8.2. It should be noted that other multiple sources (see Table I in Appendix) provided additional emissions which were not added in the calculations of these figures. As it is evident from figures 8.1a-d and 8.2, differences in the meteorological conditions resulted in distinctive differences in dispersion results between the two periods when there is evidence of transboundary transport over northern Greece (Rapsomanikis et al., 1999).

 

As mentioned before, aerosol samples were collected at Xanthi, Greece (41.15 ^oN, 25 ^oE), on a moving  glass fiber filter band GF10 6 cm width with 1 μm nominal porocity of a high volume sampler (Rapsomanikis et al, 1999). They were also collected by a PM2.5 μm High Volume Dichotomous Virtual Impactor (HVDVI) (Solomon et al., 1983) on glass fiber 90 mm diameter GF/F filters with nominal porocity of 1 μm. Parts of the filter band and parts of the HVDVI filters, constituting of 24h samples, were analysed using high resolution gas chromatography coupled with high resolution mass spectrometry by Scientific Analysis Laboratories Ltd (SAL), U.K. The background concentrations for the compounds of interest in the area was estimated from samples of filter band for days that air masses originated from the former Yugoslavia, before the onset of the conflict.

The following SVO’s were quantitatively determined:

Dioxins and furans: 2,3,7,8-TCDD; 1,2,3,7,8-PeCDD; 1,2,3,6,7,8-HxCDD; 1,2,3,4,7,8-HxCDD; 1,2,3,7,8,9-HxCDD; 1,2,3,4,6,7,8-HpCDD; OCDD; 2,3,7,8-TCDF; 1,2,3,7,8-PeCDF; 2,3,4,7,8-PeCDF; 1,2,3,4,7,8-HxCDF; 1,2,3,6,7,8-HxCDF; 2,3,4,6,7,8-HxCDF; 1,2,3,7,8,9-HxCDF; 1,2,3,4,6,7,8-HpCDF; 1,2,3,4,7,8,9-HpCDF; OCDF.

PCB’s: Tri-, tetra-, penta-, hexa- and hepta-chlorobiphenyls

PAH’s: Napthalene, Acetapthylene, Acenaphthene, Fluorene, Phenanthene, Anthralene, Fluoranthene, Pyrene, Benzo(a)anthracene, Chrysene, Benzo(b/k)fluoranthene, Benzo(a)pyrene, Indeno(123-cd)pyrene, Benzo(ghi)perylene, Dibenzo(ah)anthracene.

 

Figure 9a: Time series of 24hr integrated aerosol samples for total dioxins, furans, PCB's and PAH's. For the dates that data are not depicted, concentrations were not detectable.

 

Figure 9a, adapted from Rapsomanikis et al. (1999), shows atmospheric concentrations of total dioxins, furans, PCB’s and PAH’s. As can be seen from the time series of SVO’s in figure 9a,  the two events can be clearly distinguished from background values. In the first episode concentrations of total dioxins, furans and PCB’s increased ten fold, whilst concentrations of total PAH’s increased twenty fold.  The second episode is less prominent and increases were three fold for dioxins, furans and PAH’s whilst no increase was observed for PCB’s. The onset and end of these events is consistent with dispersion calculations depicted in figures 8.1a-d and 8.2.

 

Figure 9b: Time series of 24hr integrated aerosol samples for total phthalates. For the dates that data are not depicted, concentrations were not detectable.

 

Phthalates are used as plasticizers in a variety of plastics and are emitted in the atmosphere after burning of plastics in fires and / or municipal incinerators. Their toxicity and atmospheric concentrations are well documented with total concentrations ranging from 0.3 – 1.0 μg/m³ (California EPA, 1994,Dugenest et al., 1999, Fredricson et al., 1999). Total values for the concentration of the following phthalates were determined in the atmosphere of Xanthi: Dimethyl phthalate, Di-n-butyl phthalate, Butyl benzyl phthalate, Bis (2 ethyl hexyl)  phthalate Diethyl phthalate. Their time series in April is shown in figure 9b.

It should be emphasized that these events could not have been caused by pollution from nearby sources because of the unique combination of detected pollutant species as seen in figure 9a. Lack of similar measurements in the Balkans prevented any attempt to carry out a risk assessment analysis and a further validation of the model results.