THE SPATIAL-DISTRIBUTION OF CHARACTERIZED FLY-ASH PARTICLES AND TRACE-METALS IN LAKE-SEDIMENTS AND CATCHMENT MOSSES - CZECH-REPUBLIC

As a part of the FLAME research project funded by the EU COPERNICUS pr ogramme (1994-1996) samples of surface sediments were taken from 31 ma n-made lakes and one natural lake in the Czech Republic. The sites dif fer considerably in their altitude, area, catchment, depth, retention time, trophic status, and in parameters of local air pollution. The sa mples were analysed for concentration of spheroidal carbonaceous parti cles (SCP, numbers per gram dry mass of sediment), a characteristic co mponent of industrial fly-ash. The extracted carbonaceous particles we re allocated according to the fuel-types combusted throughout Europe ( coal, oil, brown coal, pear, oil shale) using particle chemistries der ived by energy dispersive spectroscopy (EDS). Trace metals were also a nalysed in the surface sediments as were mosses sampled at the study s ites. The main objectives of the study were (i) to look for factors de termining SCP concentrations in surface sediments of lakes, with speci al emphasis on the distribution of large fossil-fuel combustion source s (ii) to compare fuel-type allocation of carbonaceous particles with combustion of these fuels within the country, (iii) to look for trends in spatial distribution of trace metals and (iv) to characterize the impact of airborne particles from these sources on environmental and h uman health. The SCP concentrations show little or no relation to air- pollution parameters on a small scale, although some large-scale effec ts are evident. A good relationship was, however, found to site charac teristics such as altitude and lake area : catchment area. The reason, why this relationship is more apparent from our dataset than from any other study published so far, is likely to be based on the high varia tion in the physical parameters (altitude, lake and catchment area) of the sites under study. The distribution of particles attributed to br own coal combustion are in good agreement with the distribution of maj or air pollution sources across the country but the fraction of partic les attributed to coal seems to be overestimated by the present techni que. The distribution of trace metals in surface sediments are also in agreement with expected sources. The usefulness of SCP concentrations as indicators of stress to human and environmental health is briefly discussed.