Yes it is ironic that flight crew can be exposed to substantially more radiation than workers in a nuclear plant with no legal H & S implications. In the EU the curent directive states:
the limit on effective dose for exposed workers shall be 100 millisieverts ('mSv`) in a consecutive five-year period, subject to a maximum effective dose of 50 mSv in any single year. Member States may decide an annual amount.
- the limit on equivalent dose for the lens of the eye shall be 150 mSv in a year;
- the limit on equivalent dose for the skin shall be 500 mSv in a year. This limit shall apply to the dose averaged over any area of 1 cm², regardless of the area exposed;
- the limit on equivalent dose for the hands, forearms, feet and ankles shall be 500 mSv in a year.
As far as I know the US has a more relaxed ruling.
The main issue IMO is that little is known/broadcast about career cumulative effects and that should be of concern to those starting at a young age on jets that reularly climb to FL400.
Not many realise that radiation increases exponentially the highter you fly. Staying one level lower than optimum rather than one level higer will spare you quite a few millisieverts.
bear in mind that 15 years ago many aircraft had trouble climbing above FL300 - now the cumulative effects are higher.