Search

Radon and progeny are potentially relevant in radioecological studies, as they contribute more than half of the exposure to environmental radiation. The investigation of 222Rn in internal environments of municipalities of Paraíba and Rio Grande do Norte in Brazil was carried out using passive dosimetry with α Espec-222, installed in environments selected by the history of natural radiative occurrences. The monitoring time was eight months to consider seasonal influence. Concentrations from 26.91 to 316.35 Bq m-3 were obtained, with a maximum effective dose of almost 8 mSv y-1. The influence on households exceeds, by almost 31%, the average obtained for occupational environments. The municipalities of Paraíba presented higher results for Rn, with an average of almost 176 Bq m-3 and an effective dose greater than 4 mSv y-1. The application of individual occupancy factors for home and work environments made it possible to combine the dosimetric models, making the scenario closer to the real exposure of individuals who work and reside in the same municipality, with a dosimetric response of 21.45% lower than the model used worldwide. The different scenarios applied allowed expanding the radiometry of the environments, generating a database that precedes studies of environmental and radioecological impacts, strengthening security and enabling new works to interpret public health problems in search of joint and shared solutions. • Indoor radon flux was used to calculate radioecological risk. • The study shows high levels of radon indoors in areas with NORM. • Passive dosimetry was used to diagnose airborne radon levels and environmental impact. • Different situations were used to calculate the risks arising from radon exposure. • The number of cancer cases and estimated deaths in the region impacted by radon were calculated. [ABSTRACT FROM AUTHOR]

Radon is important in indoor radiometry, where radiological impact is relevant. The improvement of low-cost methods makes it possible to maximize the monitored areas. Thus, a simple and robust monitoring device based on SSNTD CR-39 was designed. Detector conditions were standardized to reduce operational errors and increase productivity. The calibration factor by the slope method allowed efficiency greater than 93%. The monitoring system is satisfactory in terms of operation and performance, suitable for a wide range of radon monitoring situations. • An air diffusion chamber (α SPEC-222) for use with a CR-39 SSNTD was developed for radon measurement. • The calibration factor was obtained by the angular coefficient method, the efficiency was higher than 93%. • The method was tested, validated, and applied in a case study to test the functionality of the spectrometer. • The measurement system is sensitive and capable of integrating response from low values to anomalous levels. [ABSTRACT FROM AUTHOR]

Biodosimetry can define risks in inhabitants of areas with potential contaminants, ensuring environmental protection and living conditions due to toxic and radioactive effects. This study aimed to evaluate metals and radionuclides in dental structures and alveolar bones in residents of a uranium area in Paraíba and Pernambuco, Brazil. Eighty-nine specimens were pulverized, fractionated, and chemically prepared for analysis by EDXRF, FAAS, and ICP-MS. Levels of Ca, Cu, Fe, Si, Mn, Ni, Pb, Sr, Ti, V, Zn, K, Mn, Th, and U were investigated. Higher concentrations were measured for Ca, with an average of 272,986.4 mg kg−1. Ni presented in lower concentrations, with an average of 30.4 mg kg−1. For U, concentrations ranged from 1.5 to 145.0 mg kg−1, with more than 27% of the samples above the reference value of 8.1 μg kg−1. For Th, almost 38% of the results were above the limit of 3.5 μg kg−1. In the bone spicules, the contents of U and Th ranged from 45.1 to 1451.2 μg kg−1 and from 7.5 to 78.4 μg kg−1, in this order. The levels of radionuclides were more expressive for the teeth collected in São José do Sabugi, suggesting contamination through food and water consumption. In the bone spicules, the levels of U were up to 179 times higher than the safety limit. The results indicate a possible risk of contamination with probable induced radiobiological effects. • Elevated Ca levels suggest environmental exposure in uranium regions. • High U concentrations in São José do Sabugi teeth imply local contamination. • Radionuclide levels in bone spicules exceed safety limits, posing health risks. • Urgent measures are needed to mitigate potential radiobiological effects. • Urgent cytogenetic evaluation is needed for genotoxic effects. [ABSTRACT FROM AUTHOR]

This research aimed to get information about the uranium and radium activity concentrations in surface and ground water in a semiarid region in Brazil. Mean (and range) activity of 0.46 (0.01–1.8), 0.015 (0.0004–0.066) and 0.32 (0.09–1.32) Bq L− 1 were found for 234U, 235U and 238U, respectively. Uranium radioisotopes account for the higher radioactivity in surface and groundwater, 226Ra was found only in few groundwater samples (0.09–0.61 Bq L− 1). 226Ra/238U (0.15–0.43) and 234U/238U (1.18–1.86) activity ratios are indicative of radioactive disequilibrium in groundwater. Expected effective doses from few water sources can be considered significant if untreated water is used for drinking. [ABSTRACT FROM AUTHOR]

In a project sponsored by the NUCLEBRÁS, were mapped uraniferous anomalies in the municipalities of Pedra and Venturosa, in the rural region of Pernambuco, Brazil. As these municipalities are the main milk producers in this State, it was of interest in this work to investigate the levels of natural uranium in milk, curdled cheese and milk whey, produced by the cattle in these districts and nearby areas. Conventional uranium fluorimetry was used for analyses. The concentrations of uranium were higher in the milk whey. The milk and cheese produced in this area are insufficient to produce toxicity in the kidneys of humans. [ABSTRACT FROM AUTHOR]

The Metropolitan Region of Recife and its surroundings are heavily exploited to capture water for public supply through tubular wells. However, a survey of the levels of natural radionuclides from these sources had never been carried out, even though part of this region contains a phosphate deposit that has a high concentration of natural uranium. In this context, this research aimed to identify 228Ra and 226Ra levels in groundwater in the coastal region of Pernambuco, Brazil. About 110 points (wells) of drinking water for public supply were identified and studies were carried out to estimate the level of ingestion and subsequent risk due to the presence of this radionuclide. The average concentration of combined radium was 104 mBq.L−1. For 228Ra an effective dose of 0.46, 0.11, 0.12 and 0.0276 mSv.y−1 for infants, children aged 1 and 10 and adults, respectively, were obtained. Although doses above those recommended by WHO were found, the equivalent dose and the induction of bone sarcoma did not indicate a risk to the population. Groundwater with higher dose values is influenced by local geology. • The activity concentration of 228Ra and 226Ra in groundwater used for public supply was determined. • The effective dose for infants and children exceeded five and two times, respectively, the value recommended by the WHO. • A strong correlation was observed between the hot spots and the geology of the area. [ABSTRACT FROM AUTHOR]

A correction to this paper has been published: https://doi.org/10.1007/s10967-021-07790-0 [ABSTRACT FROM AUTHOR]