WP 3: Regionalisation of lake micropollutant distribution

Targets     Lead Contractor     Lead Partners    

Task 3.1     Task 3.2    

Targets

Previous work has shown that organic pollutants and trace metals accumulate in both fish and sediments in remote mountain lakes. The specific organic compounds found include most of those in the UNECE persistent organic pollutant (POP) list and include both carcinogens and endocrine disruptors. Moreover, recent studies have shown that concentrations of some compounds are enhanced in mountain lakes by cold selective trapping. In this workpackage we aim to model the transport of trace metal (especially Hg, Pb and Cd) and trace organic pollutants within lake-catchment systems and understand their variability within and between Lake Districts. Special attention will be given to organic compounds as their distribution is less predictable than for metals.

Task 3.1.: Understanding and modelling transport within catchment/lake systems

The transport of trace pollutants within lakes and their catchments is insufficiently known. We will use radionuclide (210Pb, 137Cs) tracers at two Experimental sites in the Pyrenees and Tatra Mountains, both to study the transport of pollutants (inputs from the catchments, speciation, fluxes through the water column and across the water-sediment interface) and to validate mass balance models. Consideration will also be given to the role of ice-cover on sediment and pollutant fluxes using data from a series of Experimental sites.

Task 3.2.: Within and between region variability of pollutant distribution

Data on the emission and deposition of POPs are far poorer than for acidifying pollutants. We will use surface sediment samples from the Validation lakes in each Lake District to study the distribution of POPs and we will distinguish in particular two groups: those linked to pollution from combustion sources and those from other sources. Preliminary evidence shows that the former are correlated with patterns of S deposition. Consequently we will explore this relationship further and we will also compare relationships between organics, trace metals and spheroidal carbonaceous particle distributions. The distribution of organic pollutants derived from non combustion sources will be investigated in order to confirm cold selective trapping of the less volatile compounds and assess geographical trends of the most volatile ones. Older sediment samples, representing pre-industrial times, (WP 4) will also be analysed for organics and trace metals to assess the extent of contamination over time at each site and to validate deposition models.

Lead Contractor

1. CSIC - Department of Environmental Chemistry, Institute of Chemical and Environmental Research, Consejo Superior de Investigaciones Científicas, Barcelona (CSIC), Spain

Lead Partners

• ULIV - Environmental Radioactivity Research Centre, University of Liverpool, UK