低剂量的电离辐射:定义和背景
John D Harrison1, Susan McCready-Shea2, Mark A Hill3
1UK Health Security Agency, London, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.
概括
"低剂量"辐射暴露的定义因环境而异,影响风险评估. 了解这些区别对于准确的辐射保护指南至关重要.
科学领域:
- 辐射保护 辐射保护
- 辐射物理学 辐射物理学
- 公共卫生 公共卫生
背景情况:
- 辐射暴露中的"低剂量"术语缺乏通用定义,导致潜在的混.
- 像UNSCEAR和ICRP这样的组织的现有定义根据暴露情况而异.
- 剂量被用作风险的代理,但低剂量风险是不确定的,需要仔细估计.
研究的目的:
- 为了澄清"低剂量"辐射暴露的不同定义.
- 为不同的暴露场景建立特定环境的剂量值.
- 为了将剂量水平与估计的终身癌症风险联系起来.
主要方法:
- 联合国电离辐射影响科学委员会 (UNSCEAR) 和国际辐射保护委员会 (ICRP) 的定义的审查和综合.
- 在科学研究和监管指南中使用的剂量值 (mGy,mSv) 和剂量率 (mGy min-1,mSv h-1) 的分析.
- 剂量值与估计的终身癌症风险大小的相关性.
主要成果:
- 联合国安理会安全与发展委员会 (UNSCEAR) 将低吸收剂量定义为<100mGy,低剂量速率定义为<0.1mGy min-1.
- 在诊断程序中,ICRP使用<100mSv用于"低剂量"和<10mSv用于"非常低剂量".
- 对于计划暴露,建议"低剂量"为工人<10mSv,公众<1mSv.
- 这些剂量水平与估计的终身癌症风险相对应,分别为<10-2,<10-3和<10-4.
结论:
- "低剂量"辐射的特定背景定义对于风险沟通的明确性是必要的.
- 计划暴露情况的剂量限制与已确定的风险值保持一致.
- 对于大多数低剂量暴露评估,数量级风险估计是足够的.
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