Affected Model of Indoor Radon Concentrations Based on Lifestyle, Greenery Ratio, and Radon Levels in Groundwater

Abstract

Many people spend most of their day indoors, where low concentrations of radon (Rn-222) pose a significant environmental risk. Radon is a gas that decays from uranium (U-238). Its progeny can attach to aerosol and dust, and tends to get into the lungs [1]. In a previous study, 40% of all lung cancer deaths among miners were found to be related with radon progeny exposure. Indeed, 10% of all lung cancers may be caused by exposure to radon indoors: interestingly, these percentages were higher in never smokers than in smokers [2]. Another study proposed that radon poses a higher risk upon prolonged exposure at low doses than shorter exposure at higher doses [3]. Accordingly, the World Health Organization has pronounced radon as the second leading cause of lung

Residential Radon Exposure and Cigarette Smoking in Association with Lung Cancer: A Matched Case-Control Study in Korea

“…Intergroup comparisons were conducted using t-tests for continuous variables and χ2-tests for categorical variables. We used multivariate conditional logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI) for lung cancer according to residential radon exposure (high vs. low), smoking status, and combinations of the two (low-radon dwelling non-smokers [reference], high-radon dwelling smokers, low-radon dwelling smokers, and high-radon dwelling smokers), after adjusting for second-hand smoking, sleeping hours, indoor hours, housing type, floor, presence of cracks, and green ratio [22]. All analyses were performed using SAS version 9.4 (SAS Institute Inc., Cary, NC, USA).…”

“…Second-hand smoking was defined as living together with or working in proximity to a current smoker [20,21]. Green area corresponds to forest and grassland area; agricultural space, such as rice fields, is not included in green area [22].…”

A Deterministic Model for Estimating Indoor Radon Concentrations in South Korea

“…Using a structural equation model, Lee et al [8] showed that a high greenery ratio significantly increases indoor radon concentrations. The Environmental Geographic Information Service maintained by the Ministry of Environment in Korea provides access to greenery ratio data, which reflect the area of green area compared to administrative regions according to the city/county/district [9].…”

“…Meanwhile, entrance concentration rates from soil and building materials are also affected by geographical characteristics and building design. Greenery ratio can be considered a factor connected to the exhalation rate of radon from surfaces [8]; cracks in the building and floors may also be factors. Therefore, we may consider the following statistical model for estimating entrance concentration rates from the soil and building materials for residence i:Si=β0+β1X1i+β2X2i+β3Y1i+β4Y2i+β5Y3i+ϵi, where Si = entrance concentration rates from soil and building materials for each residence i, X1i= greenery ratio of the administrative district to which residence i belongs, X2i= geometric mean of indoor radon levels of the administrative district to which residence i belongs, Y1i= type of building material of residence i, Y2i=…”