Hydrogeochemical characteristics and terrestrial radiation of geothermal spring attractions in Central and Western Thailand

Abstract

The main objectives of this study were to evaluate the geochemical characteristics, reservoir temperatures (related to the natural ambient gamma radiation levels), and natural background radiation levels of the geothermal spring attractions in Central and Western Thailand. The hydrochemical properties of the geothermal waters revealed that K + -Na + bicarbonate dominates the geochemistry of these hot spring waters. Due to their chemical characteristics, the geothermal waters reflect the homogeneity of the geological formations, which indicates that limestone originated and mixed with shallow groundwater/freshwater. On the other hand, no significant correlations were found between the reservoir temperatures and naturally occurring background radiation levels. The natural background radiation levels were investigated at the main pool and 10 m from the main pool. In addition, the annual effective dose equivalent (AEDE) and excess lifetime cancer risk (ELCR) would be considered in the areas with low natural background radiation levels. The highest averages for the AEDEs and the ELCRs were discovered in the Ratchaburi Hot Spring (RB1), at approximately 0.48 and 1.90 mSv/year, respectively. Although the ELCR is slightly higher than the annual average effective dose (1.45 mSv/year) due to the natural background radiation, a preventive strategy should be considered to protect the effects on visitors' health.