The world's strongest sulphide brine used for treatment at the Physiotherapy Centre comes from the “Malina” borehole in Solec Zdrój. Classified as highly mineralised sodium chloride water (brine), it is sulphide, bromide, iodide and boron-rich, with the world's highest content of active sulphur compounds.
The effect of balneological treatments depends on the concentration of active sulphur compounds in the water. Therapeutic springs with high concentrations (over 100 mg/1L) of sulphur compounds provide the best results in spa treatment. Like any stimulation therapy, it requires a series of treatments, with therapeutic effects lasting about one year after treatment ends.
Comparison of selected
sulphide waters in
| Spring location | % mineralisation | sulphur compounds at water |
| Swoszowice | 2.64% | 70.04 mg H2S/1L |
| Krzeszowice | 0.28% | 6.00 mg H2S/1L |
| Horyniec | 0.75% | 23.00 mg H2S/1L |
| Busko-Zdrój | 1.40% | 50.00 mg H2S/1L |
| Solec-Zdrój "Malina" | 3.10% | 830 mg H2S/1L |
