Studies to determine whether underground waters in Wielkopolska Region (Poland) containing humus substances are suitable for practical purposes.

BACKGROUND Water derived from Miocene aquifer in Wielkopolska region (Poland) has a 'brown-black' colouration resulting from humus substances. Because this colour is difficult to remove, such water is considered unfit for human consumption. The presence of naturally occurring humus acids with known biochemical properties may however lend such water for use in medicine, cosmetics or agriculture. OBJECTIVES To determine and evaluate the properties of 'brown-black' Miocene waters from analysing their physico-chemistry properties, mineral content and the presence and structures of humus acids. MATERIAL AND METHODS The test material was 4 samples of intensely coloured 'brown-black' underground waters from Miocene aquifer taken from the Greater Poland region at different locations; Obrzycko and Braczewo (both by Szamotuly), Sepno (by Koscian) and in Poznan (Szkolna Street). RESULTS The water type was HCO3-Cl-Na with dissolved minerals ranging at concentrations of 828.5 mg/dm³ (Poznan) to 1600.5 mg/dm³ (Obrzycko). Fluorides were present at 0.71 mg/dm³ (Poznan) to 1.41 mg/dm³ (Braczewo) whilst iron (II) (ferrous ion) ranged from >10 mg/dm³ (Obrzycko) to 22.7 mg/dm³ (Sepno). Levels of humus acids varied between 188.6 mg/dm³ (Sepno) to 1501.8 mg/dm³ (Obrzycko) with predomination humic acids over hymatomelanic acids by factors from 1.³ to 10.6. CONCLUSIONS Due to the test water's mineral content, which includes significant levels of iron II, fluoride and humus acids (>50 mg/dm³), it is suggested that it has therapeutic value and is suitable for medicinal bath treatments and in manufacturing medical products or cosmetics.