What does the shallow dose equivalent (SDE) measure?

The shallow dose equivalent (SDE) specifically measures the external exposure of skin at a depth of 0.007 cm, which is equivalent to the thickness of the skin's outermost layer, the epidermis. This measurement is crucial in radiation protection because it helps assess the potential biological effects of external radiation exposure on the skin, particularly in scenarios involving low-energy beta particles and photons.

The focus on a shallow depth reflects the importance of evaluating skin exposure, especially in situations where personnel may be at risk from radiation sources that predominantly affect the outer layers of the skin. Understanding the SDE assists in developing safety protocols and determining compliance with established radiation exposure limits.