Harley N H, Fisenne I M, Robbins E S
Department of Environmental Medicine, New York University School of Medicine, New York, NY, USA.
Radiat Prot Dosimetry. 2012 Nov;152(1-3):14-7. doi: 10.1093/rpd/ncs214. Epub 2012 Aug 23.
The validation of human biological models for inhaled radionuclides is nearly impossible. Requirements for validation are: (1) the measurement of the relevant human tissue data and (2) valid exposure measurements over the interval known to apply to tissue uptake. Two lung models, ICRP 30(1) and ICRP 66(2), are widely used to estimate lung doses following acute occupational or environmental exposure. Both ICRP 30 and 66 lung models are structured to estimate acute rather than chronic exposure. Two sets of human tissue measurements are available: (210)Po accumulated in tissue from inhaled cigarettes and ingested in diet and airborne global fallout (239,240)Pu accumulated in the lungs from inhalation. The human tissue measurements include pulmonary and bronchial tissue in smokers, ex-smokers and non-smokers analysed radiochemically for (210)Po, and pulmonary, bronchial and lymph nodes analysed for (239,240)Pu in lung tissue collected by the New York City Medical Examiner from 1972 to 1974. Both ICRP 30 and 66 models were included in a programme to accommodate chronic uptake. Neither lung model accurately described the estimated tissue concentrations but was within a factor of 2 from measurements. ICRP 66 was the exception and consistently overestimated the bronchial concentrations probably because of its assumption of an overly long 23-d clearance half-time in the bronchi and bronchioles.
验证吸入放射性核素的人体生物学模型几乎是不可能的。验证的要求是：（1）测量相关的人体组织数据，以及（2）在已知适用于组织摄取的时间段内进行有效的暴露测量。有两种肺部模型，即国际放射防护委员会（ICRP）第30号模型（1）和ICRP第66号模型（2），被广泛用于估计急性职业或环境暴露后的肺部剂量。ICRP第30号和第66号肺部模型都是为估计急性暴露而非慢性暴露而构建的。有两组人体组织测量数据：通过吸入香烟在组织中积累并通过饮食摄入的（210）钋，以及通过吸入在肺部积累的大气全球沉降物（239,240）钚。人体组织测量包括对吸烟者、已戒烟者和非吸烟者的肺部和支气管组织进行放射化学分析以检测（210）钋，以及对1972年至1974年纽约市法医收集的肺部组织中的肺部、支气管和淋巴结进行分析以检测（239,240）钚。ICRP第30号和第66号模型都被纳入了一个适应慢性摄取的程序。这两种肺部模型都没有准确描述估计的组织浓度，但与测量值相差在2倍以内。ICRP第66号模型是个例外，它一直高估支气管浓度，可能是因为其假设支气管和细支气管的清除半衰期过长，为23天。
