Determination of the activity and the average annual dose of absorbed uranium and polonium in drinking water from Warsaw

Long term studying of uranium and radium-226 activity in drinking water in some regions of Ukraine and assessment of corresponding hypotetical irradiation doses

The article summarizes the activity concentrations data of 226Ra and the sum of uranium isotopes (∑U) in samples of drinking underground water for different regions of Ukraine studied during 1998-2023 in the radiation monitoring laboratory of the State Institution "O.M. Marzieiev Institute of Public Health National Academy of Medical Sciences of Ukraine. Arithmetic mean and standard deviations, minimum and maximum values for 226Ra and ∑U activity concentrations are presented for the entire 1240 sample set and for each region separately. Collected data show that the established state permissible level for drinking water of 1.0 Bq/l is exceeded for 226Ra in 1.1% of the studied samples, and for ∑U-in 3.9% correspondingly. The detected high levels of 226Ra and ∑U activity concentrations correspond to certain regions belonging to the Ukrainian crystalline shield territory. A comparison of the current data with the data of previous studies held during of 1989-1991 indicates a significant difference: for the previous studies the average and standard deviations are much higher. We attribute this to the fact that the centralized sampling of previous studies was random, and it was related exclusively to communal water supply systems. At the same time, the current sample set covers a much larger number of regions, different water consumers; the data set includes the results of repeated studies for a large number of sources, in particular, sources with purified water. Hypothetical exposure doses caused by consumption of 226Ra and ∑U in water for the current sample set were estimated for different age groups for each sample studied, as is, without taking into account the pattern of water consumption. The corresponding dose exceeds the WHO recommended value of 0.1 mSv per year for children under the age of one year for 220 cases (17.7%). This dose limit excess for other age groups corresponds-for children: aged 12-17 years-13.1%, aged 1-2 years-7.4%, 7-12 years old-5.6%, 2-7 years old-3.9% and for adults-4.1%.

Distribution of U and 210PO in groundwater of Kodagu district, Karnataka, India

Trace amounts of uranium along with its decay products are found in varying levels in natural soil, rocks, water and air. They are a matter of significant concern due to their carcinogenic nature. In the present work, the distribution of U and 210Po in groundwater of Kodagu District, Karnataka, India, was studied. The concentration of total U in groundwater samples was estimated using LASER and LED fluorimeter, and the activity of 210Po in groundwater was studied using electrochemical deposition followed by alpha counting method. The concentration of U and 210Po varied from 0.4 to 8.8 μgl-1 and 0.47 to 4.35 mBql-1, respectively. The ingestion dose due to U and 210Po in groundwater varied from 0.33 to 7.17 and 0.41 to 3.81 μSv y-1, respectively. The estimated U activity was found to be well below the standard safe limits of 30 μgl-1 in drinking water, as recommended by WHO and USEPA. The 210Po activity was low compared with the recommended 100 mBql-1 standard of WHO.

Natural Radionuclides in Bottled Mineral Waters Consumed in Turkey and Their Contribution to Radiation Dose

Bottled natural mineral water (BMW) consumption in Turkey is increasing every year. Depending on the local geology from which the water is extracted, BMW could be enhanced with natural radionuclides. In this study, the activity concentrations of natural radionuclides in 58 BMW samples of 25 different brands marketed in Turkey were measured using a γ-ray spectrometer with high-purity germanium (HPGe) detector. The average activity concentrations of 226Ra, 228Ra, and 40K in BMW samples were found as 0.4, 0.5, and 4.3 Bq/L, respectively. The activity concentrations of 228Ra exceeded the WHO-recommended maximum permissible limit of 0.1 Bq/L for drinking water. The annual effective dose (AED) and excess lifetime cancer risk (LCR) caused by the ingestion of each BMW sample were estimated for adults to assess radiological risks using two different scenarios based on BMW consumption rates (150 and 13 L/y). All estimated total AEDs, except for two samples, were below the guidance dose level of 100 μSv/y recommended by the World Health Organization (WHO) and Turkish regulations for drinking water. For all BMW brands, 228Ra was found as the main contributor to the AEDs. The LCR values were lower than the acceptable value of 10-3 for radiological risks.

URANIUM AND 210PO RADIONUCLIDES IN DRINKING WATER IN SOUTHERN BULGARIA AND EXPECTED RADIATION DOSES

The activity concentrations of the naturally occurring radionuclides 238U, 234U and 210Po have been determined for the first time in drinking water from certain sources in Southern Bulgaria using nuclear and radiochemical methods. The results obtained for the water samples vary in the intervals 0.6-678 mBq l-1 for 238U, 1.4-1484 mBq l-1 for 234U, <0.3-13.6 mBq l-1 for 210Po and 1.04-10.6 for the 234U/238U ratio. The annual effective dose from 238U, 234U and 210Po ranges from 1.09 to 44.1 μSv y-1, 0.78 to 46.8 μSv y-1 and 0.77 to 62.8 μSv y-1 for infants, children and adults, respectively. The annual effective dose due to consumption of drinking water is below the individual dose criterion of 100 μSv y-1 recommended by the World Health Organization. The natural radioactivity of the water sources investigated is below the national and international limits.