Abstract
Introduction: In the therapeutic use of spas, it is important to ensure the effectiveness of removal of coliform pollution in peloids and water. It is aimed that a study on microbiological characterization in the thermal habitats located in Turkey.
Method: The study was conducted on water and mud samples taken from spas in different parts of our country. The Most Probable Number (MPN) values obtained as a result of analyses of 100 ml and 300 ml water and peloid samples taken from each station for determination of the types of iron and acidophilic bacteria. Furthermore, IC50 values were calculated from the graph drawn between the concentrations water and mud concentrations and % activity values. IC45, IC50 and IC90 values indicating toxicity for granulated and anaerobic mud cultures were identified.
Results: For human health, the infection dosage of the bacteria in an individual must be about 50 IC50%. In water and mud samples, mostly iron bacteria such as Siderocapsa sp, Thiobaccillus ferrooxidans and acidophilic varieties such as Thiobaccillus acidophilus and Leptosprillum sp were identified. According to the results of the study, except for the water samples taken from stations TW-5, 6 and 15, pH value was in the range of 6-7, which indicated that it was slightly acidic. Moreover, their chemical contents and physical properties and at the same time their hygienic and microbiological characteristics were tested repeatedly through analyses.
Conclusion: We intended to make suggestions about the usability of the mud by identifying the properties of the spa muds and waters through analyses and /or make the existing mud compounds more useful by making additions/improvements to it, and thus initiating preliminary studies to set a standard.

Key words: Pollution, thermal sources, microbiologic analysis, spas, peloids