Department of Nuclear Engineering, University of Dhaka, Dhaka, Bangladesh.
Health Physics Division, Atomic Energy Centre, Dhaka, Bangladesh.
PLoS One. 2023 May 23;18(5):e0286267. doi: 10.1371/journal.pone.0286267. eCollection 2023.
Radon (222Rn), an inert gas, is considered a silent killer due to its carcinogenic characteristics. Dhaka city is situated on the banks of the Buriganga River, which is regarded as the lifeline of Dhaka city because it serves as a significant source of the city's water supply for domestic and industrial purposes. Thirty water samples (10 tap water from Dhaka city and 20 surface samples from the Buriganga River) were collected and analyzed using a RAD H2O accessory for 222Rn concentration. The average 222Rn concentration in tap and river water was 1.54 ± 0.38 Bq/L and 0.68 ± 0.29 Bq/L, respectively. All the values were found below the maximum contamination limit (MCL) of 11.1 Bq/L set by the USEPA, the WHO-recommended safe limit of 100 Bq/L, and the UNSCEAR suggested range of 4-40 Bq/L. The mean values of the total annual effective doses due to inhalation and ingestion were calculated to be 9.77 μSv/y and 4.29 μSv/y for tap water and river water, respectively. Although all these values were well below the permissible limit of 100 μSv/y proposed by WHO, they cannot be neglected because of the hazardous nature of 222Rn, especially considering their entry to the human body via inhalation and ingestion pathways. The obtained data may serve as a reference for future 222Rn-related works.
氡（222Rn）是一种惰性气体，因其致癌特性而被视为“无声杀手”。达卡市坐落在布里甘加河河畔，这条河被视为达卡市的生命线，因为它是该市主要的生活用水供应源，用于家庭和工业用途。采集了 30 个水样（10 个取自达卡市的自来水和 20 个取自布里甘加河的地表水），并用 RAD H2O 配件分析了这些水样中的 222Rn 浓度。自来水中和河水中的 222Rn 平均浓度分别为 1.54±0.38 Bq/L 和 0.68±0.29 Bq/L。所有这些值都低于美国环保署设定的 11.1 Bq/L 的最大污染限量、世界卫生组织推荐的 100 Bq/L 的安全限量以及联合国原子辐射影响科学委员会建议的 4-40 Bq/L 的范围。通过吸入和摄入途径，计算得出自来水中和河水中的总年有效剂量分别为 9.77 μSv/y 和 4.29 μSv/y。尽管所有这些值都远低于世界卫生组织提出的 100 μSv/y 的允许限值，但由于 222Rn 的危害性，这些值不能被忽视，特别是考虑到它们通过吸入和摄入途径进入人体。所得数据可作为今后与 222Rn 相关工作的参考。
