This study aimed to measure the equilibrium equivalent radon (EEC_Rn) concentration in an old building (Building-1) and a new building (Building-2) with mechanical ventilation and a natural ventilation system, respectively. Both buildings were located at the campus of University Kebangsaan Malaysia. The concentration of indoor radon was measured at 25 sampling stations using a radon detector model DOSEman PRO. The sampling was conducted for 8 h to represent daily working hours. A correlation of the radon concentration was made with the annual inhalation dose of the occupants at the indoor stations. The equilibrium factor and the annual effective dose on the lung cancer risks of each occupant were calculated at each sampling station. The average equilibrium equivalent radon measured in Building-1 and Building-2 was 2.33 ± 0.99 and 3.17 ± 1.74 Bqm⁻³, respectively. The equilibrium factor for Building 1 ranged from 0.1053 to 0.2273, and it ranged from 0.1031 to 0.16 for Building 2. The average annual inhalation doses recorded at Building-1 and Building-2 were 0.014 ± 0.005 mSv y⁻¹ and 0.020 ± 0.013 mSv y⁻¹, respectively. The annual effective dose for Building-1 was 0.034 ± 0.012 mSv y⁻¹, and it was 0.048 ± 0.031 mSv y⁻¹ for Building-2. The values of equilibrium equivalent radon concentration for both buildings were below the standard recommended by the International Commission on Radiological Protection (ICRP). However, people may have different radon tolerance levels. Therefore, the inhalation of the radon concentration can pose a deleterious health effect for people in an indoor environment.

本研究旨在测量平衡当量ra（EEC _Rn）分别集中在具有机械通风和自然通风系统的旧建筑物（1号楼）和新建筑物（2号楼）中。两座建筑均位于马来西亚Kebangsaan大学的校园内。使用DOSEman PRO型号的detector检测器在25个采样站测量了室内concentration的浓度。采样进行了8小时以代表每天的工作时间。stations浓度与室内站乘员的年度吸入剂量之间存在相关性。在每个采样站计算每个乘员患肺癌风险的平衡因子和年有效剂量。在Building-1和Building-2中测得的平均平衡当量ra为2.33±0.99和3.17±1.74 Bqm ^-3， 分别。1号楼的平衡因子范围为0.1053至0.2273，2号楼的平衡因子范围为0.1031至0.16。1号楼和2号楼记录的年平均吸入​​剂量为0.014±0.005 mSv y ^-1和0.020±0.013 mSv y ^-1。Building-1的年有效剂量为0.034±0.012 mSv y ^-1，为0.048±0.031 mSv y ^-1用于2号楼。两座建筑物的平衡等效ra浓度值均低于国际放射防护委员会（ICRP）推荐的标准。但是，人们对ra的耐性水平可能有所不同。因此，the浓度的吸入会对室内环境中的人们造成有害的健康影响。