Influence of iron ore works in Ni ná Slaná on the atmospheric deposition of heavy metals

The contribution deals with an evaluation of atmospheric deposition monitoring in 2001–2009 which was realised in the vicinity ofsiderite mining and processing works. Besides of gaseous emissions the works also produced the solid compounds of iron oxides and otherheavy metals. The iron ore plant worked up to August 2008. The atmospheric deposition (wet and dry) was determined by the modified bulkdeposition methodology. The samples were collected from seventeen monitoring sites, which are located maximally up to 8 km from the mainpollution source. Together with the deposition fluxes of heavy metals (Fe, Mn, Zn, Pb, Cu,Cr, Cd, As), the mineralogical composition,dispersion and size characteristics of solid particles were studied in selected samples. The volume content of respirable solid particles withthe diameter under 5 μm was from 6.7 to 13.2 %. Nanoparticles with the average hydrodynamic diameter in the interval of 242–558 nm werefound. High values of the deposition (median) of iron - 4111 mg.m-2.year -1, manganese - 236.6 mg.m-2.year -1 and especially toxic arsenic -8.05 mg.m-2.year -1 were measured in the area of Ni ná Slaná in the years 2001–2008 and compared with other areas. A correlation betweenemissions of solid pollutants in particular years and the deposition for these metals was observed. In 2009, after shutdown of the works,a decrease of values at the most contaminated sites of deposition by arsenic, manganese and iron about 90 % was recorded. Sucha significant change was not recorded for other studied metals.