Al-Zoughool Mustafa, Krewski Daniel
McLaughlin Center for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada.
Int J Radiat Biol. 2009 Jan;85(1):57-69. doi: 10.1080/09553000802635054.
Radon is natural radioactive noble gas that can be found in soil, water, outdoor and indoor air. Exposure to radon accounts for more that 50% of the annual effective dose of natural radioactivity. The purpose of the current review is to summarize recent literature and evaluate the weight of evidence on the adverse health effects of radon.
Radon is an established human lung carcinogen based on human epidemiological data supported by experimental evidence of mutagenesis studies in cell culture and laboratory animals. Extrapolation from cohort studies on miners suggested that radon is the second leading cause of lung cancer death after tobacco smoke. The majority of studies on the relationship between radon and other types of cancers showed weak or no association. Low levels of radon can be found in drinking water; however, radon released during water usage adds small quantities to indoor radon concentration. Studies showed that the risk of stomach cancer and other gastrointestinal malignancies from radon in drinking water is small. Studies of the genetic and cytogenetic effects of indoor radon yielded equivocal results; while radon exposure in miners induces gene mutations and chromosomal aberrations. Numerous in vitro cytogenetic studies demonstrated that radon induces different types of genetic and cytogenetic damage that is likely to play a role in radon lung carcinogenesis.
氡是一种天然放射性惰性气体，可存在于土壤、水、室外和室内空气中。氡暴露占天然放射性年有效剂量的50%以上。本综述的目的是总结近期文献，并评估有关氡对健康有害影响的证据权重。
基于细胞培养和实验动物诱变研究的实验证据所支持的人类流行病学数据，氡是已确定的人类肺癌致癌物。对矿工队列研究的推断表明，氡是仅次于烟草烟雾的第二大肺癌死亡原因。关于氡与其他类型癌症之间关系的大多数研究显示关联较弱或无关联。饮用水中可发现低水平的氡；然而，用水过程中释放的氡会使室内氡浓度少量增加。研究表明，饮用水中氡导致胃癌和其他胃肠道恶性肿瘤的风险较小。关于室内氡的遗传和细胞遗传学效应的研究结果不一；而矿工接触氡会诱发基因突变和染色体畸变。大量体外细胞遗传学研究表明，氡会诱发不同类型的遗传和细胞遗传学损伤，这可能在氡致肺癌过程中起作用。
