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2026 Vol.20, Issue 4 Preview Page

Research Article

Characteristics of Radon Exhalation Rates According to Seasonal Indoor Humidity Variations in a Residential Building

공동주택의 계절별 실내 습도 변화에 따른 라돈 방출 특성

Sun-Dong Kim1
,
Young-Kwon Yang1
,
Jung-Ha Park1*
김 선동1
,
양 영권1
,
박 정하1*
1Research Fellow, Land & Housing Institute, Dae-Jeon Metropolitan City, DaeJeon, Korea
1한국토지주택공사 토지주택연구원 수석연구원
*Corresponding Author
30 August 2026. pp. 297-307
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Abstract

This study investigates the annual characteristics of radon exhalation from building materials, which serve as the primary source of indoor radon in residential buildings. To ensure high data reliability, continuous monitoring was conducted for 13 months in an unoccupied, steady-state apartment where external environmental factors were strictly controlled.Continuous monitoring in a steady-state environment revealed that the wall exhalation rate peaks in summer (August–September) at 5.03 - 5.75 Bq/m2, which is 2.5 times higher than the winter minimum. While indoor concentrations generally followed this trend, reaching 230.6 Bq/m3 in August, temporary stagnations in June and July were attributed to external factors like natural ventilation rather than decreased emission strength. Statistical analysis revealed a strong positive correlation between RH and Exhalation, with a coefficient of determination (R2 = 0.9296, p < 0.01). This indicates that over 93% of the variance in radon exhalation is governed by indoor humidity, confirming that moisture is the dominant driver of the radon release mechanism in porous building materials. Furthermore, a ‘moisture-induced lag effect’ was observed in September, where exhalation remained at peak levels despite a slight decrease in ambient humidity, suggesting that the material’s environmental history significantly influences emission characteristics. These findings highlight the critical limitations of current single-point (short-term) radon measurement methods, which fail to account for such significant seasonal fluctuations. This study suggests the necessity of implementing humidity correction factors or transitioning toward source-term-based assessment frameworks to ensure accurate long-term radon risk evaluation in residential buildings.

Keywords
Radon concentration
Annual Exhalation Characteristics
Residential building
Indoor air pollution
키워드
라돈 농도
연간방출특성
공동주택
실내 공기 오염
References
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Information
  • Publisher :Korean Institute of Architectural Sustainable Environment and Building Systems
  • Publisher(Ko) :한국건축친환경설비학회
  • Journal Title :Journal of Korean Institute of Architectural Sustainable Environment and Building Systems
  • Journal Title(Ko) :한국건축친환경설비학회논문집
  • Volume : 20
  • No :4
  • Pages :297-307
  • Received Date : 2026-07-06
  • Revised Date : 2026-07-24
  • Accepted Date : 2026-07-29
  • DOI :https://doi.org/10.22696/jkiaebs.20260024
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