Which SI unit is used to report the equivalent dose for radiation workers?

The correct choice is the sievert (Sv), which is the SI unit specifically used to measure the equivalent dose of radiation. This measurement accounts for the biological effects of different types of radiation on human tissue, allowing for a standardized way to assess risk to radiation workers. The equivalent dose reflects not only the energy absorbed by the body but also the type of radiation involved, hence its significance in radiation safety and protection protocols.

In contrast, the gray (Gy) is the unit of absorbed dose, measuring the amount of energy deposited in a mass of tissue, but it does not consider the biological effectiveness of the radiation. The rad is an older unit of absorbed dose, equivalent to the gray, but is now largely replaced by the gray in scientific and regulatory contexts. The roentgen (R) measures exposure in air and is not directly related to the biological impact of radiation on tissue. These distinctions highlight why the sievert is the appropriate choice for discussing equivalent doses in radiation protection for workers.