Assessment of POP Transport and Accumulation in the Environment

EMEP Report 4/2001

V.Shatalov, A.Malanichev, N.Vulykh, T.Berg, S.Mano

ABSTRACT

In chapter 1 modelling results of benzo[a]pyrene (B[a]P) transboundary transport are described. At the previous stage of investigations spatial distribution of B[a]P concentrations in air, precipitation, soil, vegetation and sea water in 1997 has been estimated.

At this stage the model assessment of persistent organic pollutant (POP) is hampered by a number of uncertainties associated with rather general description of scavenging processes, gas exchange with the underlying surface, transformation and transport in accumulating compartments (soil, water and vegetation). Pollutants occurring in the atmosphere in substantial quantities in the gaseous phase (for example, PCB) present the greatest difficulty. These pollutants can be accumulated in environmental compartments and in spite of emission reduction they inflict a tangible impact on the atmospheric pollution due to volatilization processes. To avoid complex processes of the intercompartment exchange at the initial stage of investigations the elaboration of an approach to the evaluation of POP transboundary transport between countries was made on the example of B[a]P, a pollutant present in the atmosphere mainly in the aerosol phase. This study is focused on the elaboration of an approach to the evaluation of B[a]P transboundary transport between EMEP countries on the basis of "country-to-country" matrices. For this purpose the model was modified.

The chapter 2 includes a description of D&F congeners selection procedure, emission data, provisional model estimates of pollution spatial distribution in environmental compartments, and the comparison of calculation results with available measurements.

In chapter 3 the first attempts of modelling of HCB distribution over European region are considered. The emphasis is on the following:
· HCB long-range transport;
· HCB partitioning between environmental compartments in Europe;
· comparison of modelling results against measurements.

In model calculations of HCB it is necessary to pay a special attention to the following:
- The inflow of the pollutant into the calculation region.
- Wet deposition parameters.

The calculations have been carried out using expert estimates of PCB emission data, calculation results and the comparison of calculation results with available measurements of PCB concentrations in air, precipitation, soil, vegetation and sea water for 1989-98, long-term trends described in chapter 4.