Seasonal variation and structural influences on indoor radon exposure in residential buildings of Khuzestan Province

Nastaran Talepour; Alireza Mesdaghinia; Kazem Nadafi; Kamyar Yaghmaeian; Abbas Shahsavani; Masud Yunesian; Mehdi Ahmadi; Sahand Jorfi; Morteza Abdullatif Khafaie; Mohsen Hosainzadeh; Zeinab Ghaed Rahmat; Zabihollah Yousefi; Maryam Yarahmadi; Neda Kaydi; Seyede Kosar Mousavi; Shila Ghasabzadeh; Faezeh Jahedi; Masoud Panahi Fard; Zahra Hashemi; Nezamaddin Mengelizadeh; Hamed Saki; Narges Shamsedini; Mohammad Hassan Bazafkan; Ali Gourani; Saeed Ghanbari; Neamatollah Jaafarzadeh

doi:10.1038/s41598-025-15560-1

Seasonal variation and structural influences on indoor radon exposure in residential buildings of Khuzestan Province

Sci Rep. 2025 Sep 29;15(1):33350. doi: 10.1038/s41598-025-15560-1.

Authors

Nastaran Talepour¹, Alireza Mesdaghinia^{2

3}, Kazem Nadafi^{2

4}, Kamyar Yaghmaeian², Abbas Shahsavani⁵, Masud Yunesian^{2

3}, Mehdi Ahmadi^{6

7}, Sahand Jorfi^{6

7}, Morteza Abdullatif Khafaie⁷, Mohsen Hosainzadeh⁸, Zeinab Ghaed Rahmat⁹, Zabihollah Yousefi¹⁰, Maryam Yarahmadi¹¹, Neda Kaydi¹, Seyede Kosar Mousavi⁶, Shila Ghasabzadeh⁶, Faezeh Jahedi¹, Masoud Panahi Fard¹, Zahra Hashemi¹², Nezamaddin Mengelizadeh¹³, Hamed Saki⁶, Narges Shamsedini¹⁴, Mohammad Hassan Bazafkan⁶, Ali Gourani¹¹, Saeed Ghanbari¹⁵, Neamatollah Jaafarzadeh¹⁶

Affiliations

¹ Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
² Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
³ Center for Water Quality Research (CWQR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.
⁴ Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.
⁵ Air Quality and Climate Change Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
⁶ Department of Environmental Health Engineering, Ahvaz Jundishapour University of Medical Sciences, Ahvaz, Iran.
⁷ Environmental Technologies Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
⁸ Khouzestan Water and Power Organization, Ahvaz, Iran.
⁹ Department of Environmental Health Engineering, Shoushtar Faculty of Medical Sciences, Shoushtar, Iran.
¹⁰ Department of Environmental Health Engineering, Faculty of Health, Mazandaran University of Medical Sciences, Sari, Iran.
¹¹ Centre of Environmental Health and Occupational, Deputy Health, Ministry of Health and Medical Education, Tehran, Iran.
¹² Behbahan Faculty of Medical Science, Behbahan, Iran.
¹³ Department of Environmental Health Engineering, Evas Faculty of Health, Larestan University of Medical Sciences, Larestan, Iran.
¹⁴ Fars Water and Wastewater Company, Shiraz, Iran.
¹⁵ Department of Biostatistics and Epidemiology, School of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
¹⁶ Environmental Technologies Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Jaafarzadeh-n@ajums.ac.ir.

Abstract

Radon, a radioactive gas and the second leading cause of lung cancer, poses significant health risks in enclosed spaces. This study examines radon concentrations in residential buildings across Khuzestan Province, Iran, exploring seasonal variations and building-related influences, to establish a baseline radon profile and inform public health strategies. A cross-sectional study measured indoor radon levels in 343 homes using CR-39 solid-state nuclear track detectors during the cold (December-February) and warm (June-August) seasons of 2024. Stratified random sampling ensured representativeness across Khuzestan, varying in geology and urban density. Key variables included building age, height, floor type, and structural framework. Spatial distribution was mapped via Inverse Distance Weighting (IDW) and Ordinary Kriging (OK). Statistical analyses (t-tests, ANOVA) assessed differences (p < 0.05). Mean radon concentrations were higher in the cold season (119.93 ± 113.15 Bq/m²) than in the warm season (72.99 ± 41.16 Bq/m²), with northern cities like Dezful (279.05 Bq/m²) exceeding WHO (100 Bq/m²) and EPA (148 Bq/m²) thresholds. The estimated annual effective doses (AEDs) ranged from 0.78 to 7.04 mSv/year, with higher values during the cold season. Older concrete buildings (> 15 years) and ground-floor units showed significantly elevated levels (p < 0.001). Floor type influenced warm-season concentrations (p = 0.011), with mosaic floors highest (91.32 Bq/m²). Spatial analysis identified northern mountainous regions as radon hotspots, especially in the cold season. Seasonal and structural factors significantly affect radon levels in Khuzestan, highlighting public health risks in high-radon zones. Mitigation strategies, such as ventilation improvements in older concrete homes, are critical. This dataset fills a critical knowledge gap in Iran's national radon profile and provides an essential baseline for future geospatial health risk modeling, mitigation planning, and policy development.

Keywords: Building characteristics; Radon concentration; Residential buildings; Seasonal variation.

MeSH terms

Air Pollutants, Radioactive* / analysis
Air Pollution, Indoor* / analysis
Cross-Sectional Studies
Housing*
Humans
Iran
Radiation Monitoring / methods
Radon* / analysis
Seasons*

Substances

Radon
Air Pollutants, Radioactive

Grants and funding

ETRC-9423/Ahvaz Jundishapur University of Medical Sciences