Environmental cycling of selected persistent organic pollutants (POPs) in the Baltic Region

• review information on present emissions and fluxes
• assess historical emissions within and outside the study region.

Task 3. Environmental Database - to complete and update existing data base of levels of POPs in the countries around the Baltic Sea and use these data for verification of model results

Task 4. Recommendations - to prepare a set of recommendations with respect to the exposure and risk assessment for POPs in the Baltic Sea region.

Project methodology

The project is being carried out within three working groups concentrating on:

• emissions,
• compartmental modeling, and
• environmental concentration data.

Emission working group

An emission data base is being established on the basis of collected information and emission estimates within the project. The data base is structured along the major source categories agreed between the European Union program CORINAR and EMEP. It comprises information on sources (type and location), amount of activity, and amount of emitted POPs to the environment.

GIS is used to store the information on location and magnitude of POP discharges in the Baltic Sea region and to obtain information on spatial distribution of POP releases in the study region.

Model working group

The information on emissions/releases of POPs, available from the emission working group of the project, is applied in a non-steady-state multi-compartmental mass balance model based on the fugacity approach. Differences between urban and industrial centres and remote areas within one region are modeled by "nesting" small near-source compartments within the overall compart-ments representing a region.

Four major aspects related to the fate of POPs are studied with the help of the model:

• seasonal cycling,
• environmental gradients,
• land-air-sea-interactions, and
• long-term changes.

GIS is applied to the data on the environmental parameters which influence the fate of POPs, such as climatological parameters (temperatures, precipitation, sea ice cover, etc), water characteristics (e.g. concentration of suspended solids, primary productivity), and soil and sediment properties (mean depth, organic carbon content). These data are used to obtain realistic environmental input values for the model calculations.

The model results will be verified through the comparison with measurement data available from the environmental data base of the project.

Environmental data base working group.

The development of an environmental data base is the major task of this working group. The data base contains information on:

• congener and/or isomer specific con-centrations of POPs,
• sample matrix,
• site,
• date,
• descriptors about data quality,
• information on detection limits, and missing data, and
• origin and reference of the cited data.

GIS will be used during the development of the environmental data base.

The final task of the project is the elaboration of the project recommendations with focus on exposure and risk assessment for POPs in the Baltic Sea region. GIS will be used to tie together the results of the work on emissions/releases of POPs, multimedia model, and environmental data base. This combined information will be used to elaborate a set of recommendations which will concentrate on the exposure and risk assessment for POPs in the Baltic Sea area. Through GIS the collected information will be displayed in an intuitive and easily comprehensible manner.