Which unit is commonly used to quantify radiation exposure in air?

• A. rem
• B. Rad
• C. Roentgen
• D. Gy

Answer: (C)

The unit that is commonly used to quantify radiation exposure in air is the Roentgen. This unit specifically measures the amount of ionization produced in air by X-rays and gamma rays, making it particularly relevant for evaluating radiation exposure in environments where these types of radiation are present.

The Roentgen is based on the quantity of charge produced by ionizing radiation in a given volume of air and is specifically geared towards assessing exposure rather than the biological effects of radiation. This makes it a critical measure when discussing safety limits and protocols for workers in environments where radiation is present. While other units like rad, rem, and gray are related to absorbed dose and biological effects, they do not specifically address the exposure level in air as effectively as the Roentgen does.