What are the typical annual occupational dose limits for adult workers in the U.S. under 10 CFR 20 (whole body), and how do these compare to lens and skin limits?

• A. Whole body: 3 rem per year; Lens: 5 rem; Skin: 15 rem.
• B. Whole body: 7 rem per year; Lens: 20 rem; Skin: 100 rem.
• C. Whole body: 5 rem per year; Lens: 15 rem; Skin: 50 rem.
• D. Whole body: 5 rem per year; Lens: 15 rem; Skin: 25 rem.

Answer: (C)

Dose limits for occupational exposure are set per year to protect workers while allowing routine work. The whole-body (effective) dose limit is 5 rem per year, the lens of the eye limit is 15 rem per year, and the skin limit is 50 rem per year. This reflects why the numbers look like that: the whole body is governed by the broad protection of the entire body, the eye is more sensitive and has a lower threshold to protect against cataracts, and the skin can tolerate higher exposure than the eye but still has a defined annual cap. The other options propose values that don’t align with these regulatory limits (for example, lower whole-body or lens limits, or a skin limit not matching the established 50 rem).