ACCUMULATION OF HEAVY METALS IN SOILS AND ALLUVIAL DEPOSITS OF LĂPUŞ RIVER, MARAMUREŞ COUNTY, ROMANIA - Carpathian Journal of Earth And Environmental Sciences

The abandoned mining sites related to uncontrolled mine waste and acid mine drainage are one of the most serious environmental problems of Romania. The mining activities in Romania started to decline since the 90’s when economically has become unprofitable, but the consequences on the ecosystem begin to emerge: drastic decline of fish fauna, drying of the riparian vegetation of floodplains. The Baia Mare mining region offers numerous, and well studied examples for this problems. The Upper Lăpuş Valley was selected by us because of the presence of a typical terrace system, and the lack of other (no mining) industrial pollution sources. Therefore, sampling the successive levels, beginning from the actual riverbed, until the Pleistocene terrace, the historical and industrial heavy metal inflow can be separated to the natural (geological) background. The Zn, Cu, Pb and Cd concentrations in soil samples of the upper level of the floodplain are higher, that the background, reaching in some samples the attention level. The values for heavy metals are between 4.90 – 2015 ppm for Cu, 0.50 – 50.90 ppm for Cd, 5.00 – 1050 ppm for Pb and between 21.00 – 5050ppm for Zn. It is evident, that there are a historical pollution, tied to the pre-industrial mine works from Băiuţ area and to the activity of the Rojahida furnace plant. The pollution front advances downward both in alluvia and in soils of floodplain, menacing all of Lăpuş Valley, including the protected area of Lăpuş Gorge. Spreading the mineral particles in soil cover, the heavy, toxic metals will be accumulate in feedstuff, in crops and finally, in human foods.