Concentration of radon and physicochemical parameters in ground water around Kolar Gold Fields, Karnataka State, India

Estimation of radioactivity in soil and drinking water samples from Northern Gulbarga District of Karnataka

The gamma activity of the radionuclides238U, 232Th and 40K were measured in surface soil samples collected from 40 villages of Aland, Afzalpur, Ganaghapur and Kamalapur talukas of Northern Gulbarga district, Karnataka. The gamma activity of natural radionuclides were measured using 4" × 4" NaI (Tl) scintillation detector, the spectrum was analysed using a PC based 1 k MCA (winTMCA 32 scinti SPEC) and the 222Rn activity concentrations in drinking water were determined by the Emanometry method. The activity of 238U, 232Th and 40K was found to be in the range from 14.3 ± 0.3 to 64.5 ± 6.1, 15.4 ± 0.2 to 95.0 ± 4.1 and 21 ± 06 to 323 ± 09 Bq kg-1, respectively. Outdoor AED from 0.023 to 0.07 mSv y-1 and all the radiological hazards indices were well within the safe limit. The 222Rn activity in ground water is found to vary from 1.11 to 66.6 Bq l-1. The total annual effective doses due to 222Rn inhalation and ingestion range from 3.02 to 181.81 μSv y-1, respectively, with an average value of 77.18 μSv y-1.

Radon concentration measurement and effective dose assessment in drinking groundwater for the adult population in the surrounding area of a thermal power plant

Radon in the household water collected from hand pumps is measured using a continuous radon monitor. Water samples are collected from 25 villages from the surrounding regions of the National Capital Power Cooperation (NTPC), Dadri. The radon concentration ranges from 17±1 to 68±3 Bql^-1 with a mean value of 33±13 Bql^-1. The measured radon concentration in all collected samples lies well within the limit of 100 Bql^-1as set by the World Health Organization (WHO). The mean values of the annual effective dose due to ingestion of radon and due to the inhalation of radon released from water are 84±33 and 167±65 μSvy^-1, respectively. In addition, the mean values of estimated total annual effective doses are found to be 167±65 μSvy^-1. The mean value of total annual effective doses is found to be higher than the reference dose level of 100 μSvy^-1 recommended by the WHO and the United Nations Scientific Committee on the Effect of Atomic Radiation (UNSCEAR). The mean values of effective doses per annum to the lungs and stomach are 9.9±3.9 and 10.1±3.9 μSv, respectively.

GROUNDWATER AND DRINKING WATER RADON CONCENTRATIONS IN THE COASTAL AND INTERIOR AREAS OF CHENNAI METRO CITY AND ITS IMPACT ON PUBLIC HEALTH

One hundred forty-eight water samples were collected from in and around Chennai and 222Rn concentrations were measured using radon emanometry method. The average 222Rn concentration was estimated to be 6.88, 2.01, 1.17, 0.19 and 0.10 Bq L-1 for borewell water, openwell water, tank water, metro water and lake water, respectively, which were within the U.S. Environmental Protection Agency's (USEPA) Standard limit of 11.1 Bq L-1 and World Health Organization (WHO) global average 10 Bq L-1. The total effective dose obtained has varied from 0 to 157.57 μSv y-1 with ±10% standard deviation. The mean values were 19.608, 8.092, 4.692, 0.761 and 0.423 μSv y-1 for closed borewell, open well water, tank water, metro water and for lake water, respectively. All these values were below the reference point 0.1 mSv y-1 (100 μSv y-1) set by WHO.

Factors controlling the distribution of radon (222Rn) in groundwater of a tropical mountainous river basin in southwest India

Studies on occurrence of radon in the environment are receiving growing attention worldwide due to its adverse impact on human health. Despite that, the dissolved radon in water is found to be a useful tracer in many hydrogeological studies. Although, several studies focused on the occurrence of high ²²²Rn in groundwater, the processes responsible for its variation is still not well understood. Hence, an attempt has been made in the present study to elucidate the underlying factors influencing the abundance ²²²Rn in hard rock (gneissic) aquifers of Karamana River Basin, southwest India. ²²²Rn in groundwater was analyzed in 71 dug wells during the pre-monsoon period of 2017. A large variability in ²²²Rn activities (170-68,350 Bq/m³) was noticed in groundwater and high activities were mainly seen in the khondalite formation. No significant dependencies between ²²²Rn activity and depth to water table, groundwater temperature and electrical conductivity were observed. However, majority of the presence of high ²²²Rn activity in groundwater matches with the location of lineaments. Furthermore, radium content in the host rock, degree of weathering and fracturing and the emanation coefficient of the rock were found to have an important bearing on the occurrence of radon in groundwater. The underlying factors influencing the abundance of radon in hard rock aquifers were also conceptualized. Thus, the study highlights the usefulness of ²²²Rn as a potential tool in delineating the macro-structural features like fractures/lineaments that are significant repositories of groundwater, which could be explored for groundwater development in hard rock terrains.

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.

Measurement of gross alpha and beta activity concentration in groundwater of Jordan: groundwater quality, annual effective dose and lifetime risk assessment

The current study was conducted to measure the activity concentration of the gross alpha and beta in 87 groundwater samples collected from the productive aquifers that constitute a major source of groundwater to evaluate the annual effective dose and the corresponding health impact on the population and to investigate the quality of groundwater in Jordan. The mean activity concentration of gross alpha and beta in groundwater ranges from 0.26 ± 0.03 to 3.58 ± 0.55 Bq L^-1 and from 0.51 ± 0.07 to 3.43 ± 0.46 Bq L^-1, respectively. A very strong relationship was found between gross alpha and beta activity concentrations. The annual effective dose for alpha and beta was found in the range of 0.32-2.40 mSv with a mean value of 0.89 mSv, which is nine times higher than the World Health Organization (WHO) recommended limit and one and half times higher than the national regulation limit. The mean lifetime risk was found to be 45.47 × 10^-4 higher than the Jordanian estimated upper-bound lifetime risk of 25 × 10^-4. The data obtained in the study would be the baseline for further epidemiological studies on health effects related to the exposure to natural radioactivity in Jordan.