Radon Research Articles

Are fluorite mines prone to high concentrations of radon gas inside? The case of the Lújar mine in Órgiva (Granada, Southeast Spain)

The Sierra de Lújar, located in the south of Granada (Spain), hosts one of the few currently active underground fluorite mines in Spain. Considering that high concentrations of radon gas, which is the second leading cause of lung cancer after tobacco, can occur in underground workplaces, the concentration of radon gas inside a fluorite underground mine has been measured, in order to prevent health risks to workers. QueryAlthough no significant concentration of radioactive elements has been detected in the geochemical analysis, the radon gas concentration values measured ranged between 28 and 1211 Bq m−3, and there were important variations, depending on the area of the mine. Some values exceed the limits established by European regulations. Despite these high values, the annual effective dose (E) ranges between 0.13 and 5.71 mSv, in most cases being below 3 mSv, which is the recommended value in underground mines. Improvement in the ventilation of main galleries, especially in the benefit plan area (level 423), the isolation of mined-out areas using bulkhead, continuous monitoring of radon concentration, and periodic health controls to workers are estimated as the main mitigation measures to take into consideration. The findings from this research suggest that workers in this underground fluorite mine may face substantial risk of receiving radon doses that could meet or surpass the recommended thresholds established by European regulations. This underscores the imperative for additional investigations into radon levels within underground operations in Spain.

A Review on Measurement of Radon Gas Concentration in Drinking Water

Radon is a noble gas that has a high risk to the human body, and existence at various rates in soil, air and different source of water. Moreover, radon has a short lifetime but it can produce more risk to public health. Humans are good users of water by food, drinking water, vegetable, shower and dishwashing, however, we do have not good knowledge about the risk of radon, and we need to do more research because it’s one of the main factors to various types of cancer such as lung and stomach cancer. This review used different data in some research in different countries (Romania, Chania, Brazil, Sudan, India, Syria, Iraq, and Yemen) in (2012-2020) with the help of the RAD7 detector because it has higher resolution and is faster in measurement. In current review, higher average reading of radon was found in Nigeria, its reading was (36.1 Bq/L) which was more than the standard value in the world for drinking water (11.1 Bq/L). In any country there are so many factors to high and low concentration of radon in drinking water which are discussed and explained in this review.

The dynamics of Rn-222 cyclic flow within the shallow geological subsurface media as a daily temporal variated source for exhalation into the air

Extensive research on the dynamics of radon gas (Rn-222) originating from the radioactive decay of radium (Ra-226) in geological subsurface media, sheds light on its periodic release into the atmosphere. Radon is a product of the uranium-238 decay chain found within rock and soil grains. While only a fraction of the generated radon escapes (emanates) into porous spaces due to nuclear recoil, it serves as the source for subsurface gas flows and for cyclic exhalation into the soil-atmosphere interface.Ongoing study of radon movement in shallow and deep subsoil, and its emergence at the surface, reveals complete semi-diurnal, diurnal, and seasonal gas flow cycles in the subsoil. Complementary emissions occur nocturnally as radon is released into the atmosphere. Moreover, two natural driving forces govern complex semi-diurnal and diurnal flows below and above the surface. Subsurface gas movement in porous media exhibits nonlinear behavior influenced by surface temperature gradients, resulting in downward flow to depths of up to 100 m. This flow exhibits daily periodicity with depth-dependent time delays, correlating with the diurnal surface temperature cycle. Additionally, pore gas transport into and out of open boreholes responds linearly to semi-diurnal barometric pressure changes, known as barometric pumping.Beyond subsurface phenomena, Europe and Australia increasingly employ nocturnal radon measurements to study atmospheric stability and air quality, assuming that variations in local stationary near-surface radon concentrations reflect atmospheric mixing processes. Recognizing mechanisms governing radon's temporal changes within geological subsurface media highlights the need for continuous underground radon monitoring to validate variations in daily radon exhalation to the surface.On the other hand, monitoring radon at considerable depths minimizes climatic contributions and enhances the ability to discern non-periodic pre-seismic radon signals, independent of atmospheric compulsion. This research offers potential insights into seismic precursors and the complex interplay between subsurface geodynamics and atmospheric conditions.

Assessment of the use of tailings based on the legal requirements for radiation protection, from niobium mining in Minas Gerais – Brazil

Brazil is the world's largest supplier of niobium to industry, accounting for 98% of world production, with Minas Gerais supplying 80% of total production. The mineral exploration industry generates millions of tons of waste annually. In several mining industries, waste is considered a burden for companies. Based on the radiation protection exemptions for the disposal of mining waste, the study analyses the use of waste as a raw material for the construction industry. The minimum dose rate found for gamma radiation in the waste was 0.24 µSv/h and a maximum dose of 0.33 µSv/h, which corresponds to an annual dose above the population exposure limit. The radio concentrations from gamma spectrometric analyses with the Ge(HP) detector for the two samples are a maximum of 240 Bq/kg for Ra-226 and a maximum of 840 Bq/kg for Ra-228. Despite the dose values determined for gamma radiation, CNEN Resolution 179 of 2014 considers materials with natural radioactive concentrations of radium 226 and 228 of up to 1000 Bq/kg suitable for use in the cement industry. Nevertheless, further analysis must be carried out. Since the tailings contain a concentration of Ra-226 and the radio is a source of radon gas, new analyses need to be carried out targeting the exhalation of radon.

Assessment of Indoor Radon Gas Concentration in National Open University of Nigeria: A Case Study of Calabar Study Centre

The current work deals with indoor radon (222Rn) concentrations measurements in the Calabar Study Centre of the National Open University of Nigeria using a Corentium Arthings digital radon detector meter for seven days representing a short–term average measurement of indoor radon gas concentration level. The geographical coordinates were recorded using a hand-held geographical positioning system for the sample point. Measurement were taken for seven days and the following data where obtained 83±2.19 Bq/m3,80±3.69 Bq/m3,86±5.57 Bq/m3,84±1.59 Bq/m3,82±3.59 Bq/m3,81±4.89 Bq/m3 and 85 ±5.59 Bq/m3.The average radon(222Rn) concentration level was found to be 83 ± 3.87 Bq/m3 with a geometric mean of 82 ± 3.54 Bq/m3. It was observed that the radon concentration was below the reference level of 100 Bq/m3 recommended by the World Health Organization (WHO). Although the current exposure of members of the public to natural radiation is not critical, the situation could change abruptly when other activities commenced. The excess life time cancer risk calculated for 70 years, 60 years, 50 years, 40 years and 30 years were 1.72 × 10−3,1.65× 10−3,1.39× 10−3,1.44× 10−3 and 0.69× 10−3 respectively. The calculated values of the excess life time cancer risk are all higher than the set limit of 0.029 × 10−3 by International Commission on Radiological Protection. However, there are no observed cases of lung cancer epidemic in this Centre. Therefore, it is advised to use fans and effective ventilation techniques to reduce radon levels. Identifying the regions of the country where people are most at risk from radon exposure should be the main goal of any national radon policy.

Combining Radon Deficit, NAPL Concentration, and Groundwater Table Dynamics to Assess Soil and Groundwater Contamination by NAPLs and Related Attenuation Processes

Soil and groundwater contamination by NAPLs (Non-Aqueous Phase Liquids) is certainly a big issue for protecting the environment. In situ clean-up actions are routinely applied to mitigate the risk and are supplemented by monitoring surveys to assess the degree, extension, and evolution of the contamination. Radon gas is here used as a tracer of contamination because of its high solubility in non-polar solvents that produce a reduced concentration of the gas in polluted soil and groundwater with reference to radon levels in adjacent “clean” areas. This approach was employed in two sites where gasoline and diesel spillage occurred, causing soil and groundwater contamination. The two case studies were chosen because of their difference in terms of the hydrogeological features, age of the spillage, composition of residual NAPLs, and clean-up measures to test the advantages and limits of this approach in a variety of settings. Radon data, NAPL concentration in the groundwater (mainly total hydrocarbons, Methyl Tertiary-Butyl Ether and Ethyl Tertiary-Butyl Ether) and the depth of the groundwater table were periodically collected in surveys that spanned a period of two years. This dataset was statistically processed using principal component analysis to unravel which factors and attenuation processes are working in the sites and the response of the radon deficit approach to this complex series of phenomena concurrently occurring there.

Application of Rapid Identification Technology in Shallow Coal Seam Fire Detection

ABSTRACT Due to the shallow buried depth of shallow coal seam, it is easy to produce cracks through the surface during the mining process, which leads to the occurrence of fire accidents in shallow coal seam. In this paper, a rapid identification method for shallow coal seam fire area is proposed to improve the accuracy and efficiency of radon measurement by increasing the number of single gas extraction and single detection range in radon measurement process. The new method was applied in a mine in Shaanxi, China, and the location and range of the fire area were successfully delineated according to the abnormal value of radon gas. The results show that the new method can reduce the number of measuring points, improve the efficiency of radon measurement, and expand the range of single measuring point to a circular area with a radius of 10 m, which expands the detection range. This provides an important reference for the rapid identification of fire areas in shallow coal seams and the next coal mine fire prevention and extinguishing work.

Behaviourally-informed household communications increase uptake of radon tests in a randomised controlled trial

Exposure to radon gas is a leading cause of lung cancer. Testing homes for the gas is straightforward, yet most people do not undertake tests even when offered freely. We report a pre-registered randomised controlled trial of communications to encourage test uptake. Households (N = 3500) in areas at high risk of radon exposure were randomly assigned to receive (i) a the control letter from the national Environmental Protection Agency; (ii) a behaviourally-informed version of the control letter that incorporated multiple nudges, including reciprocity messages and numeric frequencies of risk; (iii) this same behaviourally-informed letter in a re-designed envelope; (iv) the behaviourally-informed letter in the re-designed enveloped with a radon risk map of the household’s county. The behaviourally-informed letter led to a large increase in test uptake, from 22% in the control condition to 33% (a 50% increase). There was no additional benefit of the re-designed envelope, which generated uptake of 30%. Including the map led some households to respond faster, but the overall uptake (26%) was weaker. The results have implications for public health communications with households and show the potential for techniques from behavioural science to help mitigate environmental risks.

Radon gas in indoor air of primary schools of Al-Najaf city, Iraq

The indoor radon concentration of 100 primary schools in Al-Najaf province, Iraq, was measured to determine students’ and staff's safety in these schools using a CR-39 nuclear track detector based on the sealed can improve technique. The results of indoor radon concentration for all schools vary from (7.47 to 44.84) Bq / m3 with an arithmetic mean (AM) of 22.26 Bq /, while the geometric mean (GM) was 20.67 Bq / m3. The concentration of 222Rn was lower than the worldwide level. Some radiological parameters like annual effective dose (AED), potential alpha energy (PAEC), exposure to radon progeny (EP), and lung cancer cases per year per million people (CPPP) were also determined. The results of these parameters point toward normal levels in the primary schools, according to ICRP, UNCER, and NCRP data.

Determination of radon activity among beach soil samples in Jeddah and Al-Qunfudhah, Saudi Arabia

Natural radioactive materials have a negative impact on public health, especially on people exposed to the sun on beaches. Due to the high temperature in Makkah Al-Mukarramah region, many people resort to going to the sea, and regarding the risks that the public is exposed to, we focus our research on studying and drawing a radiation map of the Red Sea beaches. Also, identify the risks that the public is exposed to while on the various beaches. The study was carried out using a CR-39 solid-state nuclear track detector. The results showed that the average concentration of radon gas on the beaches of Jeddah was 481.34 ± 40.63 Bq / cm3, while the average concentration of radon gas in the city of Al-Qunfudhah was 282.36 ± 38.40 Bq / cm3. 10% of the radon gas concentration values were higher than the safe limit. The mean values for radium for all measured samples were 4.41 ± 0.61 Bq/kg, while the mean values for uranium were 0.22 ± 0.03 ppm. All radium and uranium values were within the internationally permitted limits. The results of the measured beaches indicate that the Red Sea beaches in the Makkah Al-Mukarramah region are safe for use and do not have high life-threatening rates, except for Al-Hamra Corniche Beach in Jeddah, which was higher than permissible. It is recommended to monitor the beach and remove any waste so that its percentage on the beach does not increase. It is also recommended to complete the study on the rest of the Red Sea beaches.

Evaluation of radon‐induced radiation risk in indoor environments

AbstractIn general people spend most of their time in enclosed environments, therefore, they are exposed to indoor radon and its progeny. The paper discusses the variables influencing indoor radon levels. It assesses the correlation between indoor radon levels with temperature, humidity, and pressure, as well as seasonal variables. Radon activity concentrations were measured in Ege University's laboratories and Classroom using a digital radon gas detector. After statistical analysis, the results were compared to committee‐permissible limit levels (ICRP, WHO, and EU). It was found that the average radon activity concentrations were below the recommended 300 Bq m–3 limit value (EU), ranging from 58.4 to 216.0 Bq m–3. This study emphasized the significance of measuring and assessing the indoor radon levels in laboratories and classrooms in particular, in order to safeguard the students and faculty members from radon‐related health issues.

Calibration experiments for radon in drinking water measurements using portable-type electrostatic-collection radon monitors.

Portable-type electrostatic-collection radon monitors (RAD7) are often used for in-situ measurements of radon in water. In this study, we evaluated the calibration factors and their uncertainties for two RAD7 monitors based on comparative measurements with the liquid scintillation counting method. In the first experiment, we found that both RAD7 monitors had relatively large uncertainties due to leakage of radon gas that bubbled from the gaps between the lids of the desiccant container and the glass vial. Therefore, for the second experiment, these gaps were closed as much as possible using parafilm and clay, respectively. As a result, the relative uncertainties for both RAD7 monitors were significantly decreased. Furthermore, we collected spring water samples to confirm the reliability of radon concentrations. After closing the leakage point, the uncertainty of radon concentrations in spring water we measured using the typical protocol of the RAD7 were significantly lower, which improves the measurement.

Environmental assessment of several scenarios of active and passive radon control measures

In buildings, radon gas mainly enters through cracks in the floors and gaps around pipes and cables in contact with the soil, thereby increasing indoor radon levels. Like other building components or systems, the radon control measures have embodied and operational environmental impacts that have been neglected to a certain extent. While many actions have been taken recently to achieve carbon-neutral yet energy-efficient buildings, even radon control measures should be investigated not only for protecting human health since radon gas is the major source of ionising radiation for humans but also for the environment. This paper aims to undertake a comparative analysis of the embodied and operational impacts of variant radon-protective measures installed at the floor foundation level (both active and passive solutions) for new and existing buildings. In particular, this analysis includes four different measures based on radon venting from i) floor air gap created from plastic components, ii) flexible perforated pipes embedded in the gravel layer under the floor, iii) radon sump placed in the sub-floor layer, and iv) perforated tubes drilled horizontally into the subsoil under the house. In all cases, radon will be removed through a vertical exhaust pipe terminated above the roof or by a roof fan. The impacts are calculated for the life cycle assessment (LCA) stages A1-A3 (production phase) and B6 (operational energy) to determine whether future research should be focused on the reduction of environmental impacts on the production stages or the operational ones.

Autodigit-RAD: Towards an automation of the radon’s concentration dataflow in a new and innovative building

Radon is a noble, natural, and radioactive gas coming mainly from the ground which might accumulate indoors and lead each year to 200-300 deaths from lung cancer in Switzerland. A brand new and innovative living lab will be built as of 2023 in Fribourg (Switzerland) which will allow to tackle the built environment and the relationship with its occupants. Among a large panel of environmental parameters, radon gas will be continuously monitored under and around the building as well as in the building envelope. This paper aims to present the overall process of the radon dataflow: 1) design of the sensor probes, 2) implementation of the radon sensor probes in the ground and 3) go-live with the data sharing platform with the building users. Such an infrastructure will bring the opportunity to researchers to lead new and innovative radon-related research.

Profound DNA methylomic differences between single- and multi-fraction alpha irradiations of lung fibroblasts

BackgroundAlpha (α)-radiation is a ubiquitous environmental agent with epigenotoxic effects. Human exposure to α-radiation at potentially harmful levels can occur repetitively over the long term via inhalation of naturally occurring radon gas that accumulates in enclosed spaces, or as a result of a single exposure from a nuclear accident. Alterations in epigenetic DNA methylation (DNAm) have been implicated in normal aging and cancer pathogenesis. Nevertheless, the effects of aberrations in the methylome of human lung cells following exposure to single or multiple α-irradiation events on these processes remain unexplored.ResultsWe performed genome-wide DNAm profiling of human embryonic lung fibroblasts from control and irradiated cells using americium-241 α-sources. Cells were α-irradiated in quadruplicates to seven doses using two exposure regimens, a single-fraction (SF) where the total dose was given at once, and a multi-fraction (MF) method, where the total dose was equally distributed over 14 consecutive days. Our results revealed that SF irradiations were prone to a decrease in DNAm levels, while MF irradiations mostly increased DNAm. The analysis also showed that the gene body (i.e., exons and introns) was the region most altered by both the SF hypomethylation and the MF hypermethylation. Additionally, the MF irradiations induced the highest number of differentially methylated regions in genes associated with DNAm biomarkers of aging, carcinogenesis, and cardiovascular disease. The DNAm profile of the oncogenes and tumor suppressor genes suggests that the fibroblasts manifested a defensive response to the MF α-irradiation. Key DNAm events of ionizing radiation exposure, including changes in methylation levels in mitochondria dysfunction-related genes, were mainly identified in the MF groups. However, these alterations were under-represented, indicating that the mitochondria undergo adaptive mechanisms, aside from DNAm, in response to radiation-induced oxidative stress.ConclusionsWe identified a contrasting methylomic profile in the lung fibroblasts α-irradiated to SF compared with MF exposures. These findings demonstrate that the methylome response of the lung cells to α-radiation is highly dependent on both the total dose and the exposure regimen. They also provide novel insights into potential biomarkers of α-radiation, which may contribute to the development of innovative approaches to detect, prevent, and treat α-particle-related diseases.Graphical abstract

The effect of face masks on the filtration rate of Radon (222Rn) gas and its progeny in breathing air

The effect of face masks on the filtration rate of Radon (222Rn) gas and its progeny in breathing air

A Comparative Analysis of Lung Cancer Incidence and Tobacco Consumption in Canada, Norway and Sweden: A Population-Based Study.

Risk factors for developing lung cancer include tobacco smoking, exposure to second-hand smoke, radon gas, asbestos and other carcinogens, as well as air pollution and aging. Canada, Norway and Sweden are three Arctic countries that are very similar in socioeconomic status, similar in the social determinants of health and many environmental factors, including current smoking rates. However, lung cancer incidence rates differ significantly among the three countries. Since tobacco smoking is the principal risk factor for developing lung cancer, and there is a long lag time between tobacco consumption and lung cancer incidence at the population average level, a comparative analysis is conducted with historical data available publicly in the three countries to demonstrate how tobacco consumption in the past impacts lung cancer incidence decades late. The analysis shows that lung cancer incidence rates increase proportionally with the increasing tobacco consumption rates with a lag time of 20-30 years. On average, one more cigarette smoked per person per day can increase lung cancer cases by 2 to 5 per 100,000 population.

System for Indoor Comfort and Health Monitoring Tested in Office Building Environment

The use of smart technologies and the Internet of Things (IoT) is becoming more and more popular in order to enhance the overall building performance by monitoring parameters related to occupants’ comfort and health in the built environment. A new modular, custom-made and replicable IoT system is proposed based on an Arduino development board (MKR WiFi 1010) connected to the Arduino IoT Cloud. An Application Programming Interface (API) enables the integration of this system with other possible ones, thus making the system modular, custom-made and replicable. A series of parameters were simultaneously monitored over a 7-day period in two office spaces and a photovoltaic (PV)-testing laboratory. While the meteorological and comfort parameters (temperature, relative humidity, CO2) were monitored in all three spaces, the health parameters (total volatile organic compounds—TVOCs; formaldehyde—HCHO; particulate matter—PM; and radon—222Rn) were monitored only in an office setup located right next to a Chemical Analysis and Testing Laboratory. Generally, the registered values of the health parameters fell within the recommended thresholds. However, the thermal comfort parameters were constantly exceeded: over 90% of the working time in the two office spaces and 83.33% in the PV-testing laboratory. Still, the optimal relative humidity values in the monitored spaces contributed to the discomfort reduction in the occupants. Also, CO2 and TVOCs had some exceptions in particular conditions. CO2 values of up to 1500 ppm due to poor ventilation and TVOC levels of up to 1000 ppb related to chemical experiment development were registered. Also, several other peaks were recorded when monitoring HCHO as well as PM. Thus, special attention must be paid to natural ventilation or to the improvement of building characteristics. Also, the time intervals when experiments in the Chemical Analysis and Testing Laboratory are carried out should be communicated to other personnel from the nearest offices. The testing of the monitoring system over a one-week period showed that the proposed solution operated adequately, representing a reliable tool for data acquisition via the Arduino IoT Cloud.

Concentrations of respirable crystalline silica and radon among tanzanite mining communities in Mererani, Tanzania.

Globally, the number of small-scale miners (SSM) is estimated to be more than 25 million, but it supports the livelihoods of around 100 million individuals. In Tanzania, the number of SSM has increased from an estimated 150,000 in 1987 to ~1.5 million in 2017. The miners are at a high risk of occupational-related health challenges. The study aimed to assess the concentrations of respirable crystalline silica (RCS) and radon among the tanzanite mining communities in Simanjiro District, Tanzania. We carried out a cross-sectional study involving the Mererani mines in Tanzania. These are underground mines comprised of informally employed miners, i.e. SSM. Concentrations of RCS and radon gas were measured in 44 study units, i.e. 22 mining pits and within 22 houses in the general community, e.g. shops in the peri-mining community. A total of 132 respirable personal dust exposure samples (PDS), 3 from each of the study units were taken, but only 66 PDS from the mining pits were analysed, as this was the main interest of this study. Radon concentration was measured by continuous monitoring throughout the working shift (and overnight for residences) using AlphaGuard monitor. The medians and comparison to the reference values, OSHA USA PEL and WHO/IARC references, were done for RCS and radon, respectively, using SPSS Ver. 27.0.0). The median time-weighted average (TWA) concentration of the RCS in the mining pits was 1.23 mg/m3. Of all 66 personal dust samples from the mining pits, 65 (98.5%) had concentrations of RCS above the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) of 0.05 mg/m3. Mining pits had a median radon concentration of 169.50 bq/m3, which is above the World Health Organization (WHO)/International Commission on Radiation Protection (ICRP) recommended reference of 100.00 bq/m3 but not above the upper reference of 300.00 bq/m3, while the community buildings had a median radon concentration of 88.00 bq/m3. Overall, 9 (20.5%) and 17 (38.6%) radon measurements were above 300.00 bq/m3 and between 100.00 and 300.00 bq/m3 references, respectively. Specifically, in the mining pits, 9 (40.9%) test results were above 300.00 bq/m3, while none of the test results in the community was above 300.00 bq/m3. The tanzanite SSM in Mererani we highly exposed to RCS, which increases the risk of pulmonary diseases, including silicosis, tuberculosis, and pulmonary malignancies. Immediate action by OSHA Tanzania should be enforcement of wearing respirators by all miners throughout the working hours. Health education programmes to the SSM must be strengthened and OSHA Tanzania should adopt the 0.05 mg/m3 PEL, and enforce other occupational health and safety measures, including regular use of dust suppression mechanisms (water spray and wet drilling) and monitoring of RCS exposures among SSM. Monitoring of radon exposure both in the mining pits and community buildings should be conducted, and mitigation measures should be implemented in areas that exceed the reference level of 100.00 bq/m3.

Measuring radon concentration and investigation of it’s effects on lung cancer

The second most significant etiological factor contributing to the development of lung cancer, following tobacco smoking, is the presence of radon gas. Hence, the assessment of indoor radon levels within residential structures assumes paramount importance within the realm of public health. The primary objective of this investigation is to quantify the concentration of radon gas within the premises of Balikesir University Health Education and Research Hospital as well as the Faculty of Medicine Education building situated in the city of Balikesir. Furthermore, this research endeavors to ascertain the potential risk of lung cancer associated with these measured radon concentrations. To this end, an extensive, long-term (2–3 months) radon monitoring campaign was executed by strategically positioning Columbia Resin-39 (CR-39) solid-state nuclear track detectors at 28 distinct locations. The overarching aim of this effort is to comprehensively assess the health hazards posed to both staff and students and subsequently institute any requisite mitigating measures. The lowest measured value of the measured radon gas concentration is 6 Bq/m3, the highest measured value is 60 ± 8 Bq/m3. The average measurement value is 21.96 ± 3.16 Bq/m3. The measurement results were determined to be lower than the allowed radon activity concentration value in the “Radiation Safety Directive.