TRANS-BOUNDARY POP TRANSPORT

On the basis of calculations the reductions of depositions and air concentrations of all selected POPs in each particular European countries are evaluated. The relative and absolute reduction of PCDD/Fs deposition over Central and Eastern European countries in comparison with relative emission changes is given in Figures 5(a) and (b). For the considered period the maximum relative decrease in PCDD/Fs depositions was obtained for Bulgaria and Belarus (about 3 times) (Figure 5(a)). At that the character of relative decrease in PCDD/Fs total depositions did not completely coincide with that of emissions. It can partly be explained by the influence of trans-boundary transport of PCDD/Fs and by the impact of re-emission flux in these countries. The highest absolute reduction was observed in Russia, Ukraine and Poland (Figure 5(b)). 

Model calculations allow one to evaluate POP trans-boundary transport between European countries. The contributions of external sources to PCDD/Fs air concentrations in some European countries including Eastern European countries (given in black) are shown in Figure 9(a). In spite of the general decrease of contamination in Europe, the role of trans-boundary transport is yet essential. The fraction of air concentrations caused by external sources amounts approximately to 60% for Hungary, Romania and Slovakia. As it was mentioned above air contamination by PCDD/Fs is partly explained by accumulation in media with subsequent re-emission. The fraction of concentrations caused by this process can reach 10-15% in some countries (Figure 9(b)). 

Figure 9. Contributions of trans-boundary transport (a) and re-emission (b) to the POPs air pollution in some European countries in 2001 (data on Eastern European countries are given in black).

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