Which unit is commonly used to quantify occupational radiation exposure?

The appropriate unit for quantifying occupational radiation exposure is the Sievert. The Sievert is specifically designed to measure biological effects of ionizing radiation, taking into account the type of radiation and its potential impact on human health. It represents a standard measure used to assess the risk associated with radiation exposure in different scenarios, such as occupational settings.

While the Gray is a unit of absorbed dose representing the amount of radiation energy absorbed per kilogram of matter, it does not account for the biological effects of different types of radiation. Roentgen is an older unit that measures exposure to X-rays and gamma rays but does not relate directly to biological effects or risk. REM, or Roentgen Equivalent Man, was historically used but has largely been replaced by the Sievert in most contexts due to the latter's improved applicability to different types of radiation and their biological impacts.

Thus, the Sievert is the most relevant and accurate unit for quantifying occupational radiation exposure, as it encompasses the potential biological effects of exposure in a way that the other units do not.