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Radon is a natural and radioactive gas that can accumulate in indoor environments. Indoor radon concentration (IRC) is influenced, among other factors, by meteorology, which is the subject of this paper. Weather parameters impact indoor radon levels and have already been investigated, but rarely in Switzerland. Moreover, there is a strong need for a better understanding of the radon behaviour inside buildings in Switzerland for public health concerns as Switzerland is a radon prone area. Based on long-term, continuous, and hourly radon measurements, radon distributions classified according to different weather event definitions were investigated and then compared at three different study sites in Western Switzerland. Outdoor temperature influences the most indoor radon, and it is globally anti-correlated. Wind influences indoor radon, but it strongly depends on intensity, direction, and building characteristics. Precipitation influences periodically indoor radon levels relatively to their intensity. Atmospheric pressure and relative humidity do not seem to be huge determinants on IRC. Our results are in line with previous findings and provide a vivid example in Western Switzerland. This paper underlines the different influence complexities of radon, and the need to communicate about it within the broader public and with construction professionals, to raise awareness.

Radionuclide and radon levels have been investigated in soil samples and residential environments within the Mungo and Nkam Divisions of the Littoral Region. These analyses employed gamma spectrometry facilitated by a NaI (Tl) detector for soil samples, yielding average activity concentrations of 226 Ra, 232 Th, and 40  K at 23.8, 72, and 105 Bq kg −1 , respectively. Various radiological parameters were calculated to evaluate radiological hazards. Additionally, the indoor radon concentrations were quantified utilizing the CR-39 solid-state nuclear track detector (Radtrack), revealing an average concentration of 25 Bq m −3 and an associated inhalation dose of 0.66 mSv y −1 . Risk assessments for lung cancer attributable to indoor radon exposure incorporated models such as the Harley model. An observed moderate correlation between indoor radon levels and external 226 Ra concentrations implies that radon intrusion indoors might be substantially influenced by the 226 Ra present in the subjacent soil, considering the construction of residential structures directly upon these terrains.

Radon is a natural and radioactively well-known carcinogenic indoor air pollutant. Since 2020, a radon short-term proactive methodology has been proposed by Swiss authorities, which aims to evaluate the probability of overpassing the national reference value. This study aims to assess the influence of different weather parameters on indoor radon levels monitored using this methodology. To this end, different statistical tools are used, such as correlations, auto-correlations, cross-correlations, and multiple linear regressions between meteorological parameters and indoor radon levels. We show a strong influence of weather conditions on indoor radon levels in occupied, but especially unoccupied spaces. Outdoor air temperature, followed by atmospheric pressure, was identified as the most significant parameter impacting indoor radon levels. Moreover, meteorological conditions monitored five days prior to the beginning of the radon measurements might affect radon levels. We come to the conclusion that it is of paramount importance to take these meteorological conditions into account when analyzing the results of short-term measurements, and more specifically, to consider the evolution of the weather conditions five days prior to the radon measurement. This paper helps to ensure the relevance of this short-term measurement method available in Switzerland.

In Switzerland, official radon measurements in schools require either a yearlong passive measurement or a minimum three-month passive measurement during the heating season. For cases where these durations are impractical, such as before renovations, short-term methodologies have been developed to estimate radon levels. Since 2018, the Federal Office of Public Health (FOPH) has proposed a short-term real-time measurement procedure to estimate the probability of exceeding 300 Bq/m3 under pressurized winter-like conditions, using a 168-hour protocol. An alternative methodology, adapted from Norway’s 2015 protocol, considers occupancy periods and uses a 120-hour investigation window. This study aims at implementing and comparing these two approaches in schools in the Canton of Fribourg, where previous dosimetric radon measurements were available. Results reveal that both methodologies yielded comparable outcomes, identifying radon concentrations exceeding reference levels when appropriate. However, the protocol considering occupancy offers a more targeted approach, particularly when high radon levels occur outside of occupation hours. This finding emphasizes the importance of accounting for occupancy when assessing radon risks, as it optimizes remediation efforts and ensures measures are proportional to the actual health risk. Both methodologies have practical applications, but incorporating occupancy schedules can better balance safety, cost, and comfort for building occupants.

The current study was going to detect radon concentrations in one of Cairo’s subways. The radon gas was detected in certain common positions chosen for thirteen stations. Plastic cans were prepared to hold the CR-39 samples and to be positioned at their destination in the stations. The cans were installed through two periods of one month and two months. Afterwards, the track density of radon gas was calculated for all the collected samples and then the concentration of radon was estimated in the stations. It was found that the average value of Rn concentration in the thirteen stations exceeds the average normal Rn concentration indoors. The measured values are less than the recommended maximum value of 300 Bq m −3 for radiation protection of residents according to ICRP Publ. 126. The indoor average radon concentrations were found less than the action level of 300 Bq m −3 , 100 Bq m −3 , and 148 Bq m −3 as recommended by ICRP, and WHO, respectively.

The Ebro River Delta, in the northwestern Mediterranean basin, has an extension of 320 km2 and is mainly covered by rice fields. In the framework of the ClimaDat project, the greenhouse gases atmospheric station DEC was designed and installed in this area in 2013. The DEC station was equipped, among other tools, with a Picarro G2301 instrument and an ARMON (Atmospheric Radon Monitor) to measure both CH4 and CO2 and 222Rn concentrations, respectively. The variability of methane fluxes over this area and during the distinct phases of the rice production cycle was evaluated in this study using the Radon Tracer Method (RTM). The RTM was carried out using (i) nocturnal hourly atmospheric measurements of CH4 and 222Rn between 2013 and 2019 and (ii) FLEXPART-WRF back trajectories coupled with radon flux maps for Europe with a resolution of 0.05° × 0.05° available thanks to the project traceRadon. Prior to the calculation of methane fluxes by RTM, the FLEXPART-WRF model and the traceRadon flux maps were evaluated by modelling atmospheric radon concentrations at the DEC station and comparing them with observed data. RTM-based methane fluxes show a strong seasonality with maximums in October (13.9 mg CH4 m−2 h−1), corresponding with the period of harvest and straw incorporation in rice crop fields, and minimums between March and June (0.2 to 0.6 mg CH4 m−2 h−1). The total estimated methane annual emission was about 262.8 kg CH4 ha−1. These fluxes were compared with fluxes directly measured with static accumulation chambers by other researchers in the same area. Results show strong agreement between both methodologies, having both a similar annual cycle and similar monthly mean absolute values.

Radon, a naturally occurring gas originating from the ground, varies in concentration depending on geological and environmental factors. Radon-prone areas, as defined by the International Commission on Radiological Protection, exhibit significantly higher radon levels compared to other regions. Since measuring radon in every building is economically and logistically infeasible, predictive models offer a valuable alternative for assessing indoor radon levels. Using radon database provided by the Swiss Federal Office of Public Health (FOPH), extended with other data, this study evaluated four predictive methods: multiple linear regression, logistic regression, random forest regression, and random forest classification. These models incorporated diverse datasets, including geological, climatological, and building characteristics. Results revealed that random forest classification was the most effective, correctly predicting indoor radon levels above or below the 300 Bq/m3 reference threshold in 85% of cases. Random forest regression and logistic regression performed moderately, explaining 32% and 20% of variance, respectively, while multiple linear regression explained only 16% of the variance. Significant predictors included geology, building age, floor level, and foundation type, were consistent across methods, but also the previous literature. Predicting binary variables (above or below the reference level) proved more accurate than continuous radon level predictions. This study highlights the potential of machine learning methods, particularly random forest classification, to inform radon-prone area identification and guide public health interventions.

Radon, a naturally occurring radioactive gas known for its health risks, has recently gained attention for its potential protective role against COVID-19 mortality. This cross-sectional ecological study examined the relationship between indoor radon exposure and COVID-19 mortality rates across eight countries, including several European nations, the United States, and the State of Kerala, India, during the pre-vaccination period. The analyzed data on the subject were derived from recent scientific publications. The environmental aspect was represented by the variable \"indoor radon concentration or probability of exceeding a radon concentration in indoor air,\" depending on data availability. Using national radon surveys and COVID-19 mortality statistics, statistical analyses, including Spearman's correlation and Kendall Tau, were conducted between March and December 2020. The findings revealed a consistent negative correlation between radon concentrations and COVID-19 mortality rates, indicating that higher radon concentrations were associated with lower mortality rates. Regions such as Finland and Sweden, where radon exposure was relatively high, experienced significantly lower mortality. With Sweden and Finland showing a mortality risk reduction factor of respectively 1,42 and 5,47 during the first wave compared to the UK where Radon levels are very low. Although the findings are not overwhelmingly strong, the data suggest that radon exposure may have a mitigating effect on COVID-19 mortality.

An investigation was conducted to determine radon concentrations, radon exhalation rate, and potential radiological hazard parameters associated with cement collected from five factories in Sulaymaniyah city, Kurdistan region, Iraq. Using solid-state nuclear track detectors such as CR39, the samples were analyzed by etching processes. The average radon concentration, radium concentration, and radon exhalation rate were 138.16  Bq m - 3 , 0.254  Bq kg - 1 , and 0.317  Bq m - 2 h - 1 , respectively. In sample 14, radon concentrations were within the suggested range of 200–600  Bq m - 3 , and the radon exhalation rate was well below the global average of 57.600  Bq m - 2 h - 1 . In addition, parameters related to potential radiological hazards were calculated for cement samples, the average annual effective dose indoor and outdoor were 3.49 and 1.31  mSv y - 1 , so this study's value was within the global average limitations (1–5  mSv y - 1 ). Also, the excess lifetime cancer risk indoor and outdoor were 12.5 × 10 −3 and 4.69 × 10 −3 greater than the world value of 0.29 × 10 −3 .

Radon is present in most groundwater hosted by geological formations rich in uranium. It is a gas that dissolves easily in water, poses a potential health risk when present in water used in homes. For this purpose, an exploring study of radon concentration in groundwater was conducted in three selected areas in Morocco (the Anti-Atlas, the High Atlas and the Bahira areas) using RAD-7 detector. The radon contents measured in the 34 groundwater samples, range from 0.36 to 577.1 Bq L − 1 , with average of 52.99 Bq L − 1 . Among them, only three samples exceed the accepted limit of 100 Bq L − 1 , established by the world health organization and the European Commission. Considering the level recommended by U.S. environmental protection agency, 67.64% of the samples measured had concentrations greater than 11.1 Bq L − 1 . These results indicate significantly higher 222 Rn concentrations in the groundwater of the Anti-Atlas compared to the High Atlas and occidental Meseta. This disparity could be attributed to the variation in lithology between these three different regions, as the granites are mainly the primary sources of radon in the region. The obtained annual effective doses show values ranging from 0 mSv y − 1 to 2.10 mSv y − 1 for the three regions, with samples in the Anti-Atlas and Bahira exceeding the safety limit of 0.1 mSv y − 1 proposed by both the WHO and the European Commission. This exploring study is important for both the environment and human health since it can provide important information for radon-related regulations and programs.