Makirina bay peloid (N Dalmatia, Republic of Croatia) – its potential use in balneotherapy

Recent marine sediments from Makirina bay are according to their organoleptic properties, treated as peloid or healing mud, already frequently used by local people and tourists as pomades. The application of peloids in balneotherapy is mainly intended for therapeutic treatment generally related to muscle-bone skin pathologies and purposes of wellness and relaxation. Recent studies point out that one of the main factors determining the final characteristics of peloids are grain size distribution, mineralogy, cation exchange capacity (CEC), elemental and microbiological composition of initial »geological material«. As reported by previous studies Makirina Bay peloid is represented mostly by sandy silt with relatively high CEC value (63.82 meq/100g). Peloid mineral composition is dominated by dolomite and quartz, followed by illite/muscovite, aragonite, halite, calcite, and pyrite. The average concentrations of potentially toxic elements (PTE) in Makirina bay peloid determined in this research are: As (17.6 mg/kg), Cr (92.09 mg/kg), Cu (44.5 mg/ kg), Mo (31.8 mg/kg), Pb (28.9 mg/kg) and Zn (69.2 mg/kg) and are comparable to previous results. PTE contents in benthic algae Codium bursa (C. bursa) are: As (8.8 mg/kg), Cr (15.7 mg/kg), Cu (5.6 mg/kg), Mo (0.7 mg/kg), Pb (3.6 mg/ kg) and Zn (16.3 mg/kg). Calculated Transfer factors (TF) from surficial peloid (0-5 cm) to benthic algae C. bursa are <1 for all analysed PTE, indicating no PTE transfer or bioaccumulation of PTE in C. bursa. Results of microbiological research correspond to previous studies and showed no coliforms and E. coli presence in Makirina bay peloid. Our studies have shown the adequate comparability of Makirina Bay peloid with peloids already successfully used in various spa centres around the world in purposes related to wellness and therapy, but additional researches (determination of Cr and Mo mobilities) are necessary before potential use of Makirina bay peloid. 168 Darja KOMAR et al.