This Directive shall not apply to:

1. (a)

   exposure to the natural level of radiation, such as radionuclides contained in the human body and cosmic radiation prevailing at ground level;

2. (b)

   exposure of members of the public or workers other than air or spacecrew to cosmic radiation in flight or in space;

3. (c)

   aboveground exposure to radionuclides present in the undisturbed earth's crust.