Radiation Safety Practice Exam

Which dose range is expected to cause severe damage to the immune system?

1. Below 100 REM

2. 100 to 200 REM

3. 200 to 400 REM

4. 400 to 500 REM

The correct answer is: 400 to 500 REM

Severe damage to the immune system is typically associated with higher doses of radiation exposure. In the context of the dose ranges provided, exposure in the range of 400 to 500 REM is considered significant enough to cause substantial harm to the bone marrow and lymphatic tissues, which play crucial roles in immune function. At these elevated levels, the radiation can lead to a substantial decrease in the production of white blood cells, particularly lymphocytes, which are essential for a proper immune response. This can result in immunosuppression, making an individual more susceptible to infections and diseases. On the lower end of the scale, doses below 100 REM generally do not cause any observable effects on the immune system. The intermediate ranges (100 to 200 REM and 200 to 400 REM) may cause some mild effects, but they are not typically linked to severe damage. Factors such as individual health, exposure duration, and type of radiation can also influence the outcome, but the specified higher dose range is consistently recognized in radiation safety literature as posing a significant risk to the immune system.