30 Radioactive Materials Safety Manual Environmental Health and Safety J Personnel Exposure Occupational Dose Limits Current limits for occupational radiation exposure have been established at levels to: • prevent deterministic/acute radiation effects (erythema, epilation), and • minimize late/stochastic effects such as cancer or genetic damage to very low levels. These limits set by IDPH are based on the combination of external and internal exposures. To better understand the annual occupational exposure limits set by these regulatory agencies, the definitions of these limits are discussed below: External Dose • Shallow-Dose Equivalent (SDE) is the dose to the skin from an external source of ionizing radiation. • Eye (Lens) Dose Equivalent (LDE) is the dose equivalent to the lens of the eye from an external source of ionizing radiation. • Deep-Dose Equivalent (DDE) is the whole-body dose from an external source of ionizing radiation. Internal Dose • Committed Dose Equivalent (CDE) is the dose equivalent to organs or tissue that will be received from an uptake of radioactive material. • Committed Effective Dose Equivalent (CEDE) is the dose equivalent for the whole body from an uptake of radioactive material. Sum Of External and Internal Doses Total Organ Dose Equivalent (TODE) is the dose equivalent to the maximally exposed organ or tissue from external and internal sources of ionizing radiation. TODE = DDE + CDE Total Effective Dose Equivalent (TEDE) is the dose equivalent to the whole body from the combination of external and internal sources of ionizing radiation. TEDE = DDE + CEDE Table 1 provides a summary of the current annual occupational dose limits for external and internal exposures.