Indoor radon activity concentration measurements in the great historical museums of University of Naples, Italy

Gini Method Application: Indoor Radon Survey in Kpong, Ghana

In this study, the indoor radon concentrations map, starting from a sparse measurements survey, was realized with the Gini index method. This method was applied on a real dataset coming from indoor radon measurements carried out in Kpong, Ghana. The Gini coefficient variogram is shown to be a good estimator of the inhomogeneity degree of radon concentration because it allows for better constraining of the critical distance below which the radon geological source can be considered as uniform. The indoor radon measurements were performed in 96 dwellings in Kpong, Ghana. The data showed that 84% of the residences monitored had radon levels below 100 Bqm−3, versus 16% having levels above the World Health Organization’s (WHO) suggested reference range (100 Bqm−3). The survey indicated that the average indoor radon concentration (IRC) was 55 ± 36 Bqm−3. The concentrations range from 4–176 Bqm−3. The mean value 55 Bqm−3 is 38% higher than the world’s average IRC of 40 Bqm−3 (UNSCEAR, 1993).

Indoor Radon Monitoring in Kindergarten and Primary Schools in South Italy

Humans are mostly exposed to ionizing radiation through radon and its decay products. The results of indoor radon measurements in 39 kindergartens and primary schools in the Campania region of southern Italy are presented in this paper. The survey was carried out with CR-39 solid-state nuclear track detectors (SSNTDs). Radon concentrations were measured and ranged from 11 to 1416 Bq/m3, with a geometric mean of 77 Bq/m3 and a geometric standard deviation of 2. The findings revealed that 70% of the measures were below the WHO recommended level of 100 Bq/m3 and that 97 percent of the measurements were below the 300 Bq/m3 level set by Italian law.

COVID-19 and the Additional Radiological Risk during the Lockdown Period in the Province of Naples City (South Italy)

The lockdown restrictions, as a first solution to contain the spread of the COVID-19 pandemic, have affected everyone's life and habits, including the time spent at home. The latter factor has drawn attention to indoor air quality and the impact on human health, particularly for chemical pollutants. This study investigated how the increasing time indoor influenced exposure to natural radioactive substances, such as radon gas. To calculate the radiological risk, we considered the most consolidated indices used for radiation protection: annual effective dose, excess lifetime cancer risk, and the lung cancer case. Furthermore, two different exposure times were considered: pre-lockdown and post-lockdown. The lockdown increased the indoor exposure time by 4% and, consequently, the radiological risk factors by 9%. Furthermore, the reference value of 300 Bq/m3, considered acceptable for human radiation protection, may need to be lowered further in the case of conditions similar to those of the lockdown period.

Radon Survey in Bank Buildings of Campania Region According to the Italian Transposition of Euratom 59/2013

222Rn gas represents the major contributor to human health risk from environmental radiological exposure. In confined spaces radon can accumulate to relatively high levels so that mitigation actions are necessary. The Italian legislation on radiation protection has set a reference value for the activity concentration of radon at 300 Bq/m3. In this study, measurements of the annual radon concentration of 62 bank buildings spread throughout the Campania region (Southern Italy) were carried out. Using devices based on CR-39 solid-state nuclear track detectors, the 222Rn level was assessed in 136 confined spaces (127 at underground floors and 9 at ground floors) frequented by workers and/or the public. The survey parameters considered in the analysis of the results were: floor types, wall cladding materials, number of openings, door/window opening duration for air exchange. Radon levels were found to be between 17 and 680 Bq/m3, with an average value of 130 Bq/m3 and a standard deviation of 120 Bq/m3. About 7% of the results gave a radon activity concentration above 300 Bq/m3. The analysis showed that the floor level and air exchange have the most significant influence. This study highlighted the importance of the assessment of indoor radon levels for work environments in particular, to protect the workers and public from radon-induced health effects.

Determination of natural radiation levels and lifetime cancer risk in Kırıkkale, Turkey

The aim of this study is to determine the levels of background radiation in nine districts of Kırıkkale, Turkey. The outdoor gamma dose rate in the air was measured using a portable digital environmental radiation detector at 170 locations. The mean outdoor gamma dose rate in the air was determined as 121 nGy h−1 with a range between 23 and 320 nGy h−1. The annual effective dose for districts was between 0.04 and 0.59 mSv year−1 with a mean value of 0.23 mSv year−1. Excess lifetime cancer risk values for districts ranged from 0.14×10−3 to 2.07×10−3 with a mean of 0.80×10−3. The activity concentrations of 226Ra, 232Th, 40K and 137Cs in 84 soil samples were determined using HPGe detector. The mean activity values (ranges) of 226Ra, 232Th, 40K and 137Cs in soil samples were found to be 20.4 (4.9±3.0–53.0±0.8) Bq kg−1, 38.8 (3.7±0.2–163.5±1.8) Bq kg−1, 598.0 (108.5±70.2–1500.5±38.7) Bq kg−1 and 3.9 (0.2±0.1–11.9±0.7) Bq kg−1, respectively. The mean activity concentration of 232Th and 40K was higher than the world’s mean value. The mean radium equivalent activity was 119.76 Bq kg−1 which is lower than the recommended maximum value of 370 Bq kg−1. The mean external terrestrial gamma dose rate was found to be 56.71 nGy h−1. This mean value was lower than the world mean of 60 nGy h−1. The calculated external hazard value was 0.32 and within the acceptable limit which is less than unity (Hex≤1). The indoor radon concentration in 150 houses for the summer and winter seasons was determined using solid state nuclear track detector (CR-39). The mean indoor concentration for the summer season was found to be 63.27 Bq m−3 ranging from 14.0±1.5 to 288.0±21.9 Bq m−3. On the other hand, the mean indoor concentration in the winter season was found to be 86.94 Bq m−3 ranging from 17.0±4.5 to 484.0±26.9 Bq m−3. The present results showed that the radon activity concentrations in winter were 42.3% higher than in the summer. The mean annual effective dose equivalent and lifetime cancer risk were also calculated.

Radon-222 in groundwater and effective dose due to ingestion and inhalation in the city of Ibadan, Nigeria

Radon concentration in groundwater collected from the eleven Local Government Areas (LGAs) of Ibadan, Nigeria, was analyzed. Annual effective doses due to ingestion and inhalation of radon from the consumption of the water were determined. The arithmetic means (AMs) of radon concentration for the 11 LGAs varied from 2.18 to 76.75 Bq l^-1 with a standard deviation of 1.57 and 70.64 Bq l^-1, respectively. The geometric means (GMs) varied from 1.67 to 49.47 Bq l^-1 with geometric standard deviation of 2.22 and 3.04, respectively. About 58% of the 84 water samples examined had a higher concentration of radon than the 11.1 Bq l^-1 recommended by United States Environmental Protection Agency (USEPA); the AMs of six LGAs and GMs of three LGAs were higher than the recommended value. However the AMs and GMs of all the LGAs with about 93% of the water sampled were lower than the 100 Bq l^-1 recommended by the World Health Organization and EURATOM drinking water directive. The concentration of radon varied with the geological formation of the area. The AMs of the annual effective dose due to ingestion of radon in water ranged from 0.036 to 1.261 mSv y^-1, 0.071 to 2.521 mSv y^-1 and 0.042 to 1.471 mSv y^-1 for adult, child and infant, respectively and the GMs in the range of 0.026 to 0.813, 0.055 to 1.625 and 0.032 to 0.948 mSv y^-1, respectively. The AMs of 10 LGAs and GMs of 7 LGAs were higher than the recommended reference dose level of 0.1 mSv y^-1 from the consumption of water for the duration of one year for all the three categories of people. The AMs and GMs of the annual effective dose due to inhalation of radon in drinking water ranged from 0.533 to 18.82 μSv y^-1 and 0.411 to 12.13 μSv y^-1, respectively, contributing less to the overall dose.