The assessment of the annual effective dose due to ingestion of radionuclides from drinking water consumption: calculation methods

Radiological risks in Nasser lake water and their health and environmental implications

This study aimed to evaluate the activity concentrations of naturally occurring radionuclides (NORs) in Nasser Lake water, assess the associated radiological risks, and investigate the potential health and environmental impacts. The presence of these NORs is attributed to both natural geological formations, such as uranium-rich granitic and metamorphic rocks, and anthropogenic activities, including agricultural runoff. Water samples were analyzed for radium-226 (Ra-226), thorium-232 (Th-232), and potassium-40 (K-40). The Ra-226 concentration ranged from 0.08 ± 0.003 to 1.28 ± 0.06 becquerel per liter (Bq/l), mostly between 0.2 and 1.0 Bq/l, reflecting geological and anthropogenic influences. The symbol (±) represents the measurement uncertainty associated with gamma spectrometric analysis. According to international radiation safety guidelines, Ra-226 levels below 1 Bq/l are considered safe for consumption. The Th-232 concentration varied from 0.04 ± 0.001 to 0.96 ± 0.06 Bq/l, showing significant spatial variation. Similarly, K-40 concentrations ranged from 1.35 ± 0.11 to 16.57 ± 1.43 Bq/l, with some notably high values. The annual effective dose (Eff) ranged from 15.8 to 266.15 micro sievert per year (µSv/y) for adults, reaching 362.92 µSv/y for children and 221.54 µSv/y for infants. The doses for children and infants exceeded the recommended thresholds. Cancer risk (CR) assessments showed that men's mortality risks ranged from 2.56 × 10-5 to 4.10 × 10-4, while women's ranged from 2.68 × 10-5 to 4.29 × 10-4. Morbidity risks varied between 3.72 × 10-5 and 5.95 × 10-4 for men and 3.89 × 10-5 to 6.22 × 10-4 for women. These risks correlate with specific lake locations, highlighting hot spots with elevated radioactive content. Water acidity levels (pH) ranged from 6.23 to 7.9, indicating predominantly neutral to slightly alkaline conditions. These variations correlated with electrical conductivity (EC), reflecting complex interaction between pH, EC, and NORs. The study assesses gamma radiation hazards from external exposure and internal risks from alpha-emitting radionuclides, such as Ra-226 and Th-232, through water ingestion. While most samples comply with standard radiation limits, elevated radionuclide levels in certain areas pose potential health risks, particularly for vulnerable populations like children. Continuous monitoring of radiological parameters in Naser Lake is essential to trace long-term trends and ensure safety compliance. Additionally, advanced water treatment methods could help mitigate radionuclide concentrations in affected areas.

Risk assessment of gross alpha-beta activity concentration in drinking water in Kuwait: baseline measurements and review

This study measured the gross alpha and beta radiation in Kuwait's drinking water sources, including local and imported bottled and public-piped water, to assess safety and establish consumer trust. The assessment aimed to establish a baseline for gross alpha and gross beta activity levels and to validate a rapid emergency detection method, following World Health Organization (WHO) guidelines. The results indicated that gross alpha and beta radiation concentrations and total effective doses remained within the safe limits established by WHO for all water types. Specifically, the measured values were as follows: local bottled water (0.034 ± 0.002 Bq/L for alpha, 0.078 ± 0.04 Bq/L for beta, and 0.046 ± 0.022 mSv/y for total effective dose), imported bottled water (0.031 ± 0.001 Bq/L for alpha, 0.066 ± 0.02 Bq/L for beta, and 0.04 ± 0.01 mSv/y for total effective dose), and public-piped water (0.029 ± 0.0004 Bq/L for alpha, 0.041 ± 0.001 Bq/L for beta, and 0.026 ± 0.001 mSv/y for total effective dose). The measured gross alpha and beta values, which affect the total (annual) effective dose, were below the WHO reference levels for gross activity (0.5 ± 0.01 Bq/L for alpha, 1 ± 0.13 Bq/L for beta, and 0.1 mSv/y for the annual effective dose). This indicates that the water is acceptable for human consumption without any safety concerns. However, three bottled water samples exhibited higher gross beta activity concentrations than the others; these samples require specialized nuclide analysis using advanced methods to determine their radionuclide content, influencing the estimated effective dose.

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.

Human health risk assessment of potentially toxic elements and microplastics accumulation in products from the Danube River Basin fish market

The present study aimed to quantify the concentration levels of potentially toxic elements (PTEs) such as aluminum, arsenic, cadmium, chromium, copper, nickel, lead, zinc, and mercury, as well as microplastics occurrence in various tissues of fish and seafood species, commercialized in the Lower Danube River Basin. A health risk assessment analysis was performed based on the PTEs concentration levels in the muscle tissue. Estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and target cancer risk (TR) of PTEs were calculated. It was observed that the species within the seafood category registered the highest levels of PTEs. For instance, in the muscle tissue of bivalve Mytilus galloprovincialis (from the Black Sea), the highest value was observed in the case of Zn (37.693 mg/kg), and the presence of polystyrene polymer was identified. The values associated with EDI, THQ, HI, and TR of PTE exposure were significantly lower than 1.

Radiation exposure in a region with natural high background radiation originated from rare earth element deposits at Bat Xat district, Vietnam

Surface deposits of rare earth element (REE) were identified in the Bat Xat district, Northern Vietnam. As the area is inhabited, an in-depth investigation was carried out to assess the radioactivity levels and to evaluate the radiation exposure and radiological risks for the population. Samples of REE ore, soils, water and several foods locally produced were collected and analyzed by gamma spectrometry for determination of ²³²Th, ²²⁶Ra, and ⁴⁰ K. Radon (²²²Rn and ²²⁰Rn) measurements were carried out in dwellings at the villages located near by the REE deposit area, and in Hanoi for comparison. Based on the measured radionuclide concentrations, several radiological parameters were calculated to evaluate the radiological risks for the population and to compare with worldwide values. Results indicate that the representative person of the most exposed group living near the REE deposits may receive a total annual effective dose as high as 37.9 ± 10.6 mSv, i.e., approximately 16 times the world average dose of 2.4 mSv y^-1. Consequently, this area should be considered a high background radiation area. Exposure to external radiation and internal radiation from ingestion and inhalation of radionuclides were assessed separately. Radon inhalation contributed to approximately 70% of the total annual effective dose, with both radon isotopes contributing significantly, while the ingestion of local foods and water gave minor contributions to the total effective dose. Several measures were considered to improve the radiation safety and recommendations are given to relocate the most exposed members of the population.

Radiological investigation of natural carbonated spring waters from Eastern Carpathians, Romania

The current study presents a radiological water-quality assessment on 64 spring water samples from four Romanian counties. The study area is abundant in CO2-rich spring waters consumed by locals and tourists. Gross alpha activities ranged between 21 ± 2 and 7530 ± 658 mBq L−1, with 27% of the samples exceeding the WHO threshold. Gross beta values ranged from 40 ± 2 to 5520 ± 430 mBq L−1, with 29% exceeding the recommended values. Radionuclide activities fluctuated between 0.6 ± 0.08 and 81 ± 6 Bq L−1 for 222Rn, 15 ± 2 to 1154 ± 112 mBq L−1 for 226Ra, and from 18 ± 2 to 64 ± 5 mBq L−1 for 210Po. The annual effective doses attributed to radium varied between 0.002 and 0.23 mSv yr−1.