Environmental mapping of geochemical systems

As a result of technological development, the interaction between human society and the natural environment has become extremely complex and environmental problems have become a major concern. Environmental problems such as pollution emission, waste disposal and treatment, soil and water acidification and health problems are caused by natural and anthropogenic toxic compounds. These are related to the distribution and behaviour of chemical elements and require the understanding of geochemical processes in earth systems (Butcher et al. 1992, Schlesinger 1991). Environmental problems on various scales have drawn attention to the importance of environmental geochemistry and to the need for high quality environmental geochemical maps. Maps showing the distribution of elements on a regional scale have been fundamental in recognising empirical associations between trace elements and morbidity patterns in plants and animals. Well-documented case studies have proven the need to view geochemical mapping and health issues in global relations (e.g. Tan et al. 1988, Thornton 1993). Geochemical maps have also been instrumental in agricultural and landuse planning (Appleton & Ridgway 1993) and in the investigation of ecological effects of geochemical background on vegetation (Thornton 1983). Efficient management of land resources requires knowledge on the distribution of potentially harmful chemicals, such as radioactive isotopes, as well as the chemical composition of natural environments. Such information is routinely obtained from environmental geochemical maps (Ruhling & Tyler 1971, Darnley 1993). Local scale geochemical maps are primarily used for environmental impact assessment of industrial activity and waste disposal on soils, surface- and subsurface-waters (e.g. MÁFI 1997).