Radiation Safety Practice Exam

How many REM is noted as a threshold for statistical differences in stochastic effects?

1. 5 REM

2. 10 REM

3. 20 REM

4. 50 REM

The correct answer is: 10 REM

The threshold noted for statistical differences in stochastic effects is established at 10 REM. This value is derived from various epidemiological studies that have shown an increased risk of cancer and other stochastic effects at this level of radiation exposure. The term "stochastic" refers to effects that occur by chance and have a probability that increases with dose, such as cancer. At 10 REM, there is sufficient evidence to suggest a measurable increase in the risk of developing radiation-induced stochastic effects in populations exposed to such levels over time. Below this threshold, the likelihood of observing statistically significant differences in these effects is lower, making 10 REM a crucial benchmark in radiation safety and risk assessment practices. In context, the other numbers (5 REM, 20 REM, and 50 REM) do not align with the established science regarding the threshold for detecting statistical differences in stochastic effects. While different guidelines and risk models might reference various thresholds for other purposes, 10 REM is specifically associated with a level that correlates with an observable increase in risk for stochastic outcomes like cancer.