Annual effective dose associated with radioactivity in drinking water from tin mining areas in North-western Nigeria

Natural radionuclides in drinking water and annual effective dose to infant, child, and adult

This study assessed the annual effective dose from drinking water across different age categories, considering various sources of water. The water samples were collected from different locations, with the samples categorized into public drinking water systems, private wells, and bottled water. In the drinking water samples, no radionuclides other than Ra-226, Th-232, K-40, and H-3 were detected. The average tritium concentration in drinking water was measured at 1.84 Bq L-1, significantly below the permissible safety standards. The study indicated that infants received the highest annual effective dose from drinking water, averaging 0.88 mSv year-1, compared to 0.11 mSv*year-1 for children and 0.08 mSv*year-1 for adults. Among the different water sources, well water from Stublla village showed significantly elevated levels at 0.49 mSv*year-1. The highest contribution to the annual effective dose from the ingestion of drinking water comes from Ra-226, Th-232, and K-40, with average values of 1.72, 0.42, and 0.161 mSv*year-1, respectively. Despite these variations, the average annual effective doses from drinking water for infants, children, and adults were 0.81, 0.098, and 0.076 mSv year-1, respectively. Based on drinking water sources, the Stublla region had the highest yearly effective dosage, with an average value of 0.49 mSv year-1.

Natural radioactivity in sachet drinking water produced in Ibadan, Oyo State, Nigeria

Natural radioactivity in 20 brands of sachet water produced in Ibadan, Oyo State, Nigeria, was analyzed using well-shielded, calibrated NaI(Tl) gamma spectroscopy. The measured activity concentration varies from 0.41 ± 0.05 Bql-1 to 8.78 ± 0.97 Bql-1 for 232Th and 4.29 ± 0.4 Bql-1 to 37.48 ± 2.51 Bql-1 for 40 K, and below detection level for 226Ra. The mean annual effective dose calculated for the age groups 0-1 year, 1-2 years, 2-7 years, 7-12 years, 12-17 years, and > 17 years is 4.63, 0.54, 0.49, 0.51, 0.55, and 0.68 mSv respectively. The total annual effective dose from consumption of some of the sachet water exceeded the world average values of 0.12 mSv reported by UNSCEAR. The values also exceed the WHO- and ICRP-recommended values of 0.1 mSv and 1.0 mSv respectively. This showed that there might be radiological risks arising from the consumption of the analyzed sachet water.

A review on radionuclide pollution in global soils with environmental and health hazards evaluation

Human populations are being exposed to a wide spectrum of radiation from soils as a result of the availability of radiation sources. Assessing the ecological and health effects of radionuclides in soils is crucial to support the optimal soil management practices but large-scale studies are limited. This study compiled data on radionuclides (226Ra, 232Th, 40K, 238U, and 137Cs) in soils located across the world (44 countries and 159 places) between 2008 and 2022 and applied radiological hazards indices and several multivariate statistical approaches. The average activity concentration (Bq/kg) of 226Ra, 232Th, 40K, 238U, and 137Cs were 408.56, 144.80, 508.78, 532.78, and 83.12, respectively, whereas 226Ra, 232Th, 40K, and 238U exceeded the standard limits. The principal component analysis explained more than 91% of variation in soils. Based on the geoaccumulation index, 40K posed moderately to heavy contamination whereas 238U and 226Ra posed moderate contamination in soils. Moreover, the mean values of radiological hazards evaluation such as radium equivalent activity (487.17 Bq/kg), external radiation hazard indices (1.32), internal hazard indices (2.15), absorbed dose rate (247.86 nGyh-1), annual effective dose rate (1.82 mSvy-1), activity utilization index (4.54) and excess lifetime cancer risk (63.84 × 10-4) were higher than recommended limit suggesting significant radiological risks in study region soils. The findings indicated that the study area soils were contaminated by radionuclides and unsafe for hazards in terms of the health risks linked with studied radioactive contents. The study is valuable for mapping radioactivity across the globe to determine the level of radioactivity hazards.