CDPH Lead Inspector/Assessor California State Practice Exam

According to the ALARA principle, what three aspects should be kept to a minimum to reduce radiation exposure?

1. Time, Distance, Cost

2. Time, Distance, Frequency

3. Time, Distance, Shielding

4. Shielding, Frequency, Cost

The correct answer is: Time, Distance, Shielding

The ALARA principle, which stands for "As Low As Reasonably Achievable," is a key concept in radiation safety aimed at minimizing radiation exposure to individuals. The correct choice highlights three critical factors that can be managed to reduce exposure effectively: time, distance, and shielding. By minimizing time spent near a source of radiation, the total exposure is reduced because exposure is directly proportional to the duration of contact. The longer an individual is exposed to radiation, the greater the potential dose received. Increasing distance from the source of radiation is another fundamental protective measure. As the distance from a radiation source increases, the intensity of radiation decreases significantly due to the inverse square law. This means that even a small increase in distance can lead to a substantial reduction in exposure. Shielding involves using materials to block or absorb radiation, thereby reducing the dose that reaches an individual. Different types of radiation may require different shielding materials, but generally, dense materials like lead or concrete are effective. By employing shielding techniques, radiation exposure can be further reduced. The other choices do not align with the key aspects of the ALARA principle. While frequency and cost are important considerations in safety planning and resource allocation, they are not directly related to the three fundamental strategies for minimizing radiation exposure as outlined