Which unit measures the effects of ionizing radiation on humans?

The unit that measures the effects of ionizing radiation on humans is the rem, which is a derived unit of measurement that expresses the biological effect of ionizing radiation. The rem accounts for the type of radiation and its impact on human tissue, which is crucial for assessing health risks associated with radiation exposure. This makes it particularly relevant in the context of radiation protection and safety, as it helps quantify the effective dose of radiation that individuals may receive from exposure.

In contrast, other units like the gray measure the absorbed dose of radiation but do not take into account the biological effects of different types of radiation. The roentgen, while also used to describe radiation exposure, is specific to X-rays and gamma rays and does not convey the risk to humans in terms of biological effect. Similarly, the rad denotes the absorbed energy but, like the gray, does not incorporate the biological impact of that energy on human health. Understanding the rem's role in expressing health risk makes it essential for those working in environments where exposure to ionizing radiation occurs, emphasizing the importance of using the rem for effective radiation safety management.