Sevc J, Tomasek L, Kunz E, Placek V, Chmelevsky D, Barclay D, Kellerer A M
Institute for Hygiene and Epidemiology, Praha, Czechoslovakia.
Health Phys. 1993 Apr;64(4):355-69. doi: 10.1097/00004032-199304000-00002.
The major Czechoslovak cohort of uranium miners (S-cohort) is surveyed in terms of diagrams illustrating dependences on calendar year, age, and exposure to radon and radon progeny. An analysis of the dose dependence of lung cancer mortality is performed by nonparametric and, subsequently, by parametric methods. In the first step, two-dimensional isotonic regression is employed to derive the lung cancer mortality rate and the relative excess risk as functions of age attained and of lagged cumulated exposure. In a second step, analytical fits in terms of relative risk models are derived. The treatment is largely analogous to the methods applied by the BEIR IV Committee to other major cohorts of uranium miners. There is a marked dependence of the excess risk on age attained and on time since exposure. A specific characteristic of the Czechoslovak data is the nonlinearity of the dependence of the lung cancer excess risk on the cumulated exposure; exposures on the order of 100 working level months or less appear to be more effective per working level month than larger exposures but, in the absence of an internal control group, this cannot be excluded to be due to confounders such as smoking or environmental exposures. A further notable observation is the association of larger excess risks with longer protraction of the exposures.
对捷克斯洛伐克主要的铀矿矿工队列（S队列）进行了调查，通过图表展示了其与历年、年龄以及氡和氡子体暴露的相关性。首先采用非参数方法，随后采用参数方法对肺癌死亡率的剂量依赖性进行分析。第一步，运用二维等渗回归得出肺癌死亡率和相对超额风险，作为达到的年龄和滞后累积暴露的函数。第二步，根据相对风险模型得出分析拟合结果。该处理方法在很大程度上类似于BEIR IV委员会应用于其他主要铀矿矿工队列的方法。超额风险对达到的年龄和暴露后的时间有显著依赖性。捷克斯洛伐克数据的一个特定特征是肺癌超额风险对累积暴露的依赖性呈非线性；100工作水平月及以下的暴露似乎每工作水平月比更大的暴露更有效，但由于没有内部对照组，这不能排除是由于吸烟或环境暴露等混杂因素所致。另一个值得注意的观察结果是，超额风险越大与暴露持续时间越长相关。
