Some physicochemical parameters and 226Ra concentration in groundwater samples of North Guilan, Iran.

The 226Ra concentration and some physicochemical parameters have been measured in thermal spring waters used for medical therapy and drinking purposes in the Astara basin of North Guilan, Iran. The radon emanation method was performed using the AB-5 photomultiplier tube to measure the 226Ra concentration in water samples. Also, the physicochemical parameters of the water were measured in situ using a portable multimeter-VWR multi. The average concentrations of 226Ra were ranged between 3.4 ± 0.06 to 38.2 ± 0.08 mBq l-1. For all samples, the 226Ra concentration values range is lower than the maximum admissible value recommended by the WHO report. The relation between the physicochemical parameters and 226Ra activity concentration of groundwater was assessed. The results indicate a significant correlation coefficient between 226Ra concentration and T, as well as acidity pH. Anomalously high 226Ra concentrations in groundwater are preferentially found in high temperate and electric conductivity along with the acidic environment.