EN
Poland belongs to main sources of pollution reaching Baltic Sea. From Polish territory with a river runoff it is transported 11 % of N load and 37% of P load. Most of the nutrients come from non-point sources, which are generated from agriculture areas of the river basins. It is known that Polish agriculture is in a phase of recession due to economical changes after year 1989 transformation. To understand what is an influence of these changes and environment protection investments in Poland on an improvement of river water quality this study has been performed. River basins at Polish coast (Rega, Parsęta, Słupia, Reda, Pasłęka), and at Swedish coast (Rönne, Lagan, Nissan, Ätran, Viskan) have been compared. Main criteria of the river basins selection was their size, dominance of agriculture in land-use, similar hydrological conditions, and available data on river runoff and chemistry. Temporal changes in water quality has been studied using averaged environmental monitoring data from periods 1990-1993 and 1994-1997, as well as socioeconomic data from census survey in 1988 versus 1997 (1995 in Sweden). It has been found that in Polish basins reduction of point pollution sources took place, combined with extension of water supply systems. Agriculture shows a decrease in production intensity, which results in lower nutrients loads reaching rivers. These two factors can explain a radical decrease of nutrients loads reaching Baltic from Polish basins. This is visible especially in case of P. Further improvement of water quality in case of Polish basins can be achieved by increase of volume of sewage treated in the countryside, and reduction of non point pollution in ecotone zones.