Ressortforschungsberichte zur kerntechnischen Sicherheit und zum ...

6 Summary
This feasibility study for an epidemiological study in Germany investigating the relation-
ship between exposure to ionising radiation and cataract consists of a systematic review of
the literature, devises criteria for the evaluation of relevant studies (work package 1),
evaluates the existing collectives potentially suitable for a new study (work package 2) and
evaluates two of the found collectives in greater detail (work package 3).
6.1 Results of work package 1
In work package 1, 19 publications of epidemiological studies dealing with radiological
doses below 400 mSv were retrieved: Eight studies on occupationally exposed persons with
protracted exposure (Adams et al. 1983; Chodick et al. 2008; Chylack, Jr. et al. 2009;
Cucinotta et al. 2001; Jacobson 2005; Jones et al. 2007; Milacic 2009; Rafnsson et al.
2005), one study on Chernobyl liquidators (Worgul et al. 2007), six population-based
cohort studies with medical or environmental exposure (Chen et al. 2001; Day et al. 1995;
Hourihan et al. 1999; Hsieh et al. 2010; Klein et al. 1993; Klein et al. 2000) and four
publications on atomic bomb survivors (Choshi et al. 1983; Minamoto et al. 2004;
Nakashima et al. 2006; Yamada et al. 2004).
The results of these studies do not give a clear picture on the dose-effect-relationship.
However, the individual studies do hint at a threshold lower than the one of 0,5 Gy assumed
so far by ICRP, which is also mentioned in the 2007 report (ICRP 2007). Since April 2010,
the ICRP recommends an annual maximum dose of 50 mSv as limit of a protracted exposi-
tion, with a 5-year average of max. 20 mSv (ICRP 2011).
The following criteria need to be taken into account as important prerequisites for a new
study on this topic:
- The examination of a sufficiently large exposure relevant, homogenous population with
a well comparable control group.
- A complete registration of the chosen population and a minimization of participation
and selection bias, including a non-responder analysis.
- The quantification of the lens dose in mGy in good precision by suitable dose recon-
struction.
- A reproducible and classifiable documentation of the cataract.
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