Getting a Handle on Radiation Doses

How many atomic explosions in our cities would you accept before deciding that nuclear power is not safe - no complexities, just a number? - Ralph Nader, 1974

A significant source of confusion regarding the measurement of radiation parameters is the simultaneous use of two systems of units. As noted in chapter 7, "activity" is measured in curies in the USA system and Becquerels in the International System of units. A similar duality is found in the measurement of "doses" of radiation, as will be discussed in this chapter.

The question arises as to which units should be used in this book. Personally, I think in terms of the USA units and find that most people actively involved in radiation related disciplines in the United States do likewise. On the other hand, most scientific papers are written using the S.I. values - certainly all the recent ones on hormesis.

Since neither way will satisfy all readers, it will be the policy herein to use both in the next few chapters - generally the S.I. units followed by the USA units in parenthesis unless a quotation or other source is expressed in the USA units... in which case the S.I. units are given parenthetically. Hopefully this repetition will get you accustomed to both systems of units and the relationship between them. Later chapters will use the same units as found in the source material. The plan is for you to become familiar with both by then and to make any necessary conversions in your head. (Or refer to Table 6 on page 51 or to Table 7, coming up on page 56, another good place for a bookmark.)

We will start with the more familiar (at least to me) USA units.