Radiation can also cause birth defects and genetic damage. There are several different ways of measuring radiation and its potential biological effects. Radiation may be measured in terms of the number of disintegrations per unit time or by the amount of ionization damage caused by the exposure of matter to the radiation. The curie was derived from the amount of disintegrations per second released by one gram of the radioactive element radium. Alternatively, a becquerel is one disintegration per second.
Roentgens describe the amount of ionization produced from radiation exposure.
Roentgens are especially used with energetic radiation, such as gamma rays and X-rays. For our purposes, roentgens, rads, and rems are approximately equal. However, Figure 7.15 does not define what percentages of the population actually contract these adverse health effects. Figure 7.15 suggests that all or nearly all humans that are exposed to 10,000 roentgens would immediately die from extensive body damage. We don't know.