Public exposure to radon has attracted increasing public concern. The newly issued "Standards for indoor air quality (GB/T 18883-2022)" has revised the radiological parameters of radon. This study analyzed and discussed the relevant technical contents about the derivation of radon limit, including the distribution level for indoor radon, exposure pathway, health effects, and the process for establishing the standard limits. Specific implementation and evaluation suggestions are also proposed.
Humans ; Radon/analysis* ; Air Pollution, Indoor ; China ; Housing

Public exposure to radon has attracted increasing public concern. The newly issued "Standards for indoor air quality (GB/T 18883-2022)" has revised the radiological parameters of radon. This study analyzed and discussed the relevant technical contents about the derivation of radon limit, including the distribution level for indoor radon, exposure pathway, health effects, and the process for establishing the standard limits. Specific implementation and evaluation suggestions are also proposed.
Humans ; Radon/analysis* ; Air Pollution, Indoor ; China ; Housing

Since the Compton camera was fi rst introduced, various types of conical Radon transforms have been examined. Here, we derive the inversion formula for the conical Radon transform, where the cone of integration moves along a curve in three-dimensional space such as a helix. Along this three-dimensional curve, a detailed inversion formula for helical movement will be treated for Compton imaging in this paper. The inversion formula includes Hilbert transform and Radon transform. For the inversion of Compton imaging with helical movement, it is necessary to invert Hilbert transform with respect to the inner product between the vertex and the central axis of the cone of the Compton camera. However, the inner product function is not monotone. Thus, we should replace the Hilbert transform by the Riemann–Stieltjes integral over a certain monotone function related with the inner product function. We represent the Riemann–Stieltjes integral as a conventional Riemann integral over a countable union of disjoint intervals, whose end points can be computed using the Newton method. For the inversion of Radon transform, three dimensional fi ltered backprojection is used. For the numerical implementation, we analytically compute the Hilbert transform and Radon transform of the characteristic function of fi nite balls. Numerical test is given, when the density function is given by a characteristic function of a ball or three overlapping balls.
Methods ; Radon

Radon is a naturally occurring radioactive material formed by the slow decay of uranium and thorium found in the earth's crust or construction materials. Internal exposure to radon accounts for about half of the natural background radiation dose to which humans are exposed annually. Radon is a carcinogen and is the second leading cause of lung cancer following smoking. An association between radon and lung cancer has been consistently reported in epidemiological studies on mine workers and the general population with indoor radon exposure. However, associations have not been clearly established between radon and other diseases, such as leukemia and thyroid cancer. Radiation doses are assessed by applying specific dose conversion coefficients according to the source (e.g., radon or thoron) and form of exposure (e.g., internal or external). However, regardless of the source or form of exposure, the effects of a given estimated dose on human health are identical, assuming that individuals have the same sensitivity to radiation. Recently, radiation exceeding the annual dose limit of the general population (1 mSv/yr) was detected in bed mattresses produced by D company due to the use of a monazite-based anion powder containing uranium and thorium. This has sparked concerns about the health hazards for mattress users caused by radiation exposure. In light of this event, this study presents scientific information about the assessment of radon and thoron exposure and its human implications for human health, which have emerged as a recent topic of interest and debate in society.
Background Radiation ; Beds ; Carcinogens ; Construction Materials ; Epidemiologic Studies ; Humans ; Korea ; Leukemia ; Lung Neoplasms ; Miners ; Radiation Exposure ; Radon ; Smoke ; Smoking ; Thorium ; Thyroid Neoplasms ; Uranium

Radon is a naturally occurring radioactive material that is formed as the decay product of uranium and thorium, and is estimated to contribute to approximately half of the average annual natural background radiation. When inhaled, it damages the lungs during radioactive decay and affects the human body. Through many epidemiological studies regarding occupational exposure among miners and residential exposure among the general population, radon has been scientifically proven to cause lung cancer, and radon exposure is the second most common cause of lung cancer after cigarette smoking. However, it is unclear whether radon exposure causes diseases other than lung cancer. Media reports have often dealt with radon exposure in relation to health problems, although public attention has been limited to a one-off period. However, recently in Korea, social interest and concern about radon exposure and its health effects have increased greatly due to mass media reports of high concentrations of radon being released from various close-to-life products, such as mattresses and beauty masks. Accordingly, this review article is intended to provide comprehensive scientific information regarding the health effects of radon exposure.
Background Radiation ; Beauty ; Beds ; Epidemiologic Studies ; Human Body ; Inhalation Exposure ; Korea ; Lung ; Lung Neoplasms ; Masks ; Mass Media ; Miners ; Occupational Exposure ; Radon ; Smoking ; Thorium ; Uranium

Radon is a naturally occurring radioactive material formed by the slow decay of uranium and thorium found in the earth's crust or construction materials. Internal exposure to radon accounts for about half of the natural background radiation dose to which humans are exposed annually. Radon is a carcinogen and is the second leading cause of lung cancer following smoking. An association between radon and lung cancer has been consistently reported in epidemiological studies on mine workers and the general population with indoor radon exposure. However, associations have not been clearly established between radon and other diseases, such as leukemia and thyroid cancer. Radiation doses are assessed by applying specific dose conversion coefficients according to the source (e.g., radon or thoron) and form of exposure (e.g., internal or external). However, regardless of the source or form of exposure, the effects of a given estimated dose on human health are identical, assuming that individuals have the same sensitivity to radiation. Recently, radiation exceeding the annual dose limit of the general population (1 mSv/yr) was detected in bed mattresses produced by D company due to the use of a monazite-based anion powder containing uranium and thorium. This has sparked concerns about the health hazards for mattress users caused by radiation exposure. In light of this event, this study presents scientific information about the assessment of radon and thoron exposure and its human implications for human health, which have emerged as a recent topic of interest and debate in society.
Background Radiation ; Beds ; Carcinogens ; Construction Materials ; Epidemiologic Studies ; Humans ; Korea ; Leukemia ; Lung Neoplasms ; Miners ; Radiation Exposure ; Radon ; Smoke ; Smoking ; Thorium ; Thyroid Neoplasms ; Uranium

Radon is a naturally occurring radioactive material classified as a carcinogen by the World Health Organization, and is known to be the factor with the second-greatest impact on lung cancer after smoking. An association between radon and lung cancer has consistently been reported in epidemiological studies on mine workers and residents of homes with indoor radon exposure. However, associations between radon and other diseases, such as leukemia and thyroid cancer, have yet to be confirmed due to a lack of consistent research findings and biological relevance. Such associations are unlikely because there is a very low likelihood that organs other than the lungs are exposed to radon upon inhalation due to the short half-life of radon and its progeny and the low permeability of alpha rays. In spring 2018, the radon bed mattress incident occurred, leading to a spike of concern and interest among the public regarding the health effects of radiation exposure. This paper presents a description of radon exposure and its health effects based on the current literature and provides practical information based on health consultations experienced following the 2018 radon mattress incident.
Alpha Particles ; Epidemiologic Studies ; Half-Life ; Inhalation ; Leukemia ; Lung ; Lung Neoplasms ; Miners ; Permeability ; Radiation Exposure ; Radon ; Referral and Consultation ; Smoke ; Smoking ; Thyroid Neoplasms ; World Health Organization

PURPOSE: Exposure to indoor radon is associated with lung cancer. This study aimed to estimate the number of lung cancer deaths attributable to indoor radon exposure, its burden of disease, and the effects of radon mitigation in Korea in 2010. MATERIALS AND METHODS: Lung cancer deaths due to indoor radon exposure were estimated using exposure-response relations reported in previous studies. Years of life lost (YLLs) were calculated to quantify disease burden in relation to premature deaths. Mitigation effects were examined under scenarios in which all homes with indoor radon concentrations above a specified level were remediated below the level. RESULTS: The estimated number of lung cancer deaths attributable to indoor radon exposure ranged from 1946 to 3863, accounting for 12.5–24.7% of 15623 total lung cancer deaths in 2010. YLLs due to premature deaths were estimated at 43140–101855 years (90–212 years per 100000 population). If all homes with radon levels above 148 Bq/m3 are effectively remediated, 502–732 lung cancer deaths and 10972–18479 YLLs could be prevented. CONCLUSION: These findings suggest that indoor radon exposure contributes considerably to lung cancer, and that reducing indoor radon concentration would be helpful for decreasing the disease burden from lung cancer deaths.
Korea ; Lung Neoplasms* ; Lung* ; Mortality, Premature ; Radon*

No abstract available.
Lung Neoplasms* ; Lung* ; Radon*

Radon, the primary constituent of natural radiation, is the second leading environmental cause of lung cancer after smoking. To confirm a relationship between indoor radon exposure and lung cancer, estimating cumulative levels of exposure to indoor radon for an individual or population is necessary. This study sought to develop a model for estimate indoor radon concentrations in Korea. Especially, our model and method may have wider application to other residences, not to specific site, and can be used in situations where actual measurements for input variables are lacking. In order to develop a model, indoor radon concentrations were measured at 196 ground floor residences using passive alpha-track detectors between January and April 2016. The arithmetic mean (AM) and geometric mean (GM) means of indoor radon concentrations were 117.86±72.03 and 95.13±2.02 Bq/m³, respectively. Questionnaires were administered to assess the characteristics of each residence, the environment around the measuring equipment, and lifestyles of the residents. Also, national data on indoor radon concentrations at 7643 detached houses for 2011-2014 were reviewed to determine radon concentrations in the soil, and meteorological data on temperature and wind speed were utilized to approximate ventilation rates. The estimated ventilation rates and radon exhalation rates from the soil varied from 0.18 to 0.98/hr (AM, 0.59±0.17/hr) and 326.33 to 1392.77 Bq/m²/hr (AM, 777.45±257.39; GM, 735.67±1.40 Bq/m²/hr), respectively. With these results, the developed model was applied to estimate indoor radon concentrations for 157 residences (80% of all 196 residences), which were randomly sampled. The results were in better agreement for Gyeonggi and Seoul than for other regions of Korea. Overall, the actual and estimated radon concentrations were in better agreement, except for a few low-concentration residences.
Background Radiation ; Exhalation ; Gyeonggi-do ; Korea ; Life Style ; Lung Neoplasms ; Methods ; Models, Theoretical ; Radon* ; Seoul ; Smoke ; Smoking ; Soil ; Ventilation ; Wind