The terms are more or less interchangeable in this case; radioactive isotopes produce ionizing radiation (in the form of alpha particles, beta particles, and gamma rays) so they're the same in terms of outcome. Anyway, the radiation received from stuff that's naturally occuring in the human body is almost negligible. You get way more from eating stuff containing radioactive isotopes, like bananas or red meat (both of which contain potassium), and about 3x that in radon gas inhalation (which varies depending on various geological factors).
Nuclear detonations have had an effect on the composition of the atmosphere, but it is very small, and this radiation is basically only relevant when building extremely sensitive radiation detectors.
The terms are more or less interchangeable in this case; radioactive isotopes produce ionizing radiation (in the form of alpha particles, beta particles, and gamma rays) so they're the same in terms of outcome. Anyway, the radiation received from stuff that's naturally occuring in the human body is almost negligible. You get way more from eating stuff containing radioactive isotopes, like bananas or red meat (both of which contain potassium), and about 3x that in radon gas inhalation (which varies depending on various geological factors).
Nuclear detonations have had an effect on the composition of the atmosphere, but it is very small, and this radiation is basically only relevant when building extremely sensitive radiation detectors.