engleski

Determination of arsenic and co-occurring ions levels in mineral sources dedicated to medical applications near Srebrenica (Bosnia and Herzegovina)

Srebrenica area (eastern Bosnia-y-Herzegovina) is well known for its long mining history as well as for its mineral waters of specific composition (1). As a matter of fact, such waters are used since several tens of years for medical applications either by direct ingestion, application, or through bath in spas. Sediments analysis in one of these water springs, Ljepotica (1), showed that they are very rich in arsenic, lead and iron. Our study was dedicated to the Bijela Rijeka river, nearby Srebrenica, in the framework of an Bosnia/Croatia/France Econet program. This river is having many tributaries (among whose Ljepotica source), with various flows, each used for medical purposes: skin health, eyes troubles, general well being, sanatorium, … The aim of our study was to quantify arsenic concentration as well as its co-occurring ions in the main body of the river but also in the tributaries. On site measurements revealed that for each tributary, pH was very acidic (between 2.2 and 3.2) associated to very high Eh (between 579 and 623 mV) except for one source whose pH and Eh were respectively 6.0 and 65 mV. River/tributary water mixing leads to strong FeIII precipitation. Dissolved organic content is very low all along the river, from 0.67 to 0.35 mgC/L respectively upstream and downstream the tributaries, probably due to co-precipitation with FeIII. Furthermore, the various observed precipitations at the point where tributary reaches the river main body will be modelled by PHREEQC calculations, to better understand the processes involved in the water chemistry. Even if the tributaries flows are weak, they induce a decrease of Bijela Rijeka river pH down to 3.3 (against 7.3 upstream the tributaries). Concomitantly, arsenic determination in the waters underlined very high levels in the tributaries (above 3000 µg/L, dramatically exceeding the French limit for drinkable water), which raised Bijela Rijeka river arsenic concentration from natural levels (around 3 µg/L) to a worrying value above 600 µg/L downstream the tributaries. It would be of interest to study biota adaptability to such strong chemical changes. These results raise questions about environmental consequences and people health when ingestion, direct application or skin contact are concerned. It has to be underlined that Srebrenica tap water, pumped in another geological basin, presents As concentration below 10 µg/L.

arsenic ; mineral source ; medical application

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