Gross alpha/beta activity concentrations in spa and mineral waters in North Vietnam

Abstract

There is little available information on the radioactivity concentrations in the thermal and drinking water sources in North Vietnam. In the current study, the gross alpha and gross beta activity concentrations were determined in 8 water sources in the area. The average activities of gross alpha and beta in the 8 sources are 38.7 mBq L− 1 and 88.0 mBq L− 1. These activity concentrations are lower than WHO recommendations for drinking water. In this study, the gross alpha and gross beta show a weak correlation.

210Po characteristic in selected thermal water sources in Northern Vietnam

“…210 Po is one of the natural isotopes, which emits alpha particles and contributes the gross alpha dose in the water samples. A high correlation between gross alpha and TDS was reported previously by Van Duong [26] for the water sources in the current study (R = 0.94 and correlation is significant at the 0.01 level (2-tailed).…”

“…The coordinates, the pH value, temperature, TDS, the 210 Po activity concentration, and the observed chemical components in the investigated thermal water samples are presented in Table 1. Therein the pH, temperature and TDS were previously reported by Van-Hao [26]. The pH value for all investigated water samples is neutral, except for water samples from KB and IO, which are slightly alkaline.…”

“…The low 210 Po activity in hot mineral water sources in the study area may be also related to the physicochemical properties of the water sources. The hot water storage area is in fractured carbonate strata, which has been clarified in the study of Van Duong [26], allowing for the possibility of radon gas escape for aquifers, which directly supply 210 Po. Research by Harada [2] and Seiler [7] suggested that 210 Po in groundwater is often not supported by 210 Pb because in this environment there is no radioactive equilibrium between 210 Po and 210 Pb, so 210 Po is mobilized from aquifer sediments [2,6].…”

“…During sampling, the pH, TDS, and temperature values were measured in situ by Hanna instruments model HI8314 and HI2003-02 devices. All the collected water samples are from aquifers hosted in various limestone formations [26]. Therein, the mineral water in My Lam aquifer is formed and stored in crystalline limestone, marble, and sericite slate [27].…”

“…Each water sample was taken with a 5-L plastic can and acidified to pH 2 to prevent polonium from being hydrolyzed and absorbed to the surface of the plastic can wall [12]. The followed water sampling procedure is described in [26].…”