Radiation Safety Practice Exam

What is the consequence of an acute dose of 900 REM or higher?

1. Severe illness but potential for recovery

2. Almost always fatal

3. Minor effects that require monitoring

4. Symptoms will only appear after several weeks

The correct answer is: Almost always fatal

An acute dose of 900 REM or higher is associated with significant and often lethal effects on the human body. At this level of radiation exposure, the dose exceeds the threshold of what is considered survivable for most individuals, leading to severe radiation sickness. This condition arises from extensive damage to the body's rapidly dividing cells, particularly those in the bone marrow lining and the gastrointestinal tract. At such high doses, the individual may experience a rapid onset of severe symptoms, including nausea, vomiting, diarrhea, and neurological deficits, manifesting within hours to days after exposure. The likelihood of death is very high, with survival being almost impossible due to the severe disruption of essential bodily functions, such as immune system impairment and organ failure. In contrast, lower doses may allow for recovery depending on various factors, such as medical intervention and individual health status, but 900 REM is exceedingly lethal, rendering it a definitive threshold for fatal outcomes in most cases. Thus, the correct answer highlights the gravity and near certainty of fatality associated with such a high dose of radiation exposure.