Radiation Protection Standards

Goals and Philosophy
Preventing the occurrence of radiation-related ailment has always been the goal of protection standards. The 1987 NCRP Exposure Limits are a very popular reference but since then, decades of new data and discovery has led us to keep much of the same dose limits in the workplace and for the general public. This is not the case for fetal exposures, which have become more stringent over the years.
There is a common theme among all protection standards: radiation protection must be based on the principals of justification, dose limitation and the application of ALARA (as low as reasonably achievable). The effectiveness of operating under the basic principles of radiation protection is demonstrated across all occupations in the U.S. in which exposure to radiation is possible. (NCRP Report No. 160). NCRP recommendations and guidance documents have had a great influence on the application and implementation of these principles, and protection of the population while permitting the beneficial use of technologies that may lead to radiation exposure. The shortfall of these documents is that they don't attempt to quantify the associated health risks nor do they specify the actions that should be taken.
Report No.94 came out in 1987 and is available here in both hardcover and pdf format for a fee of $68.00.

Occupational Exposure
There is a misconception that those who work with radiation on a daily basis have elevated risk levels. This is only partially true, since rigorous guidelines are put in place to guide those who work with radionuclides and other forms of radiation. The limits set concerning the workplace are based on observed biological effects which have been studied for decades and also on individual judgment. These remain largely unchanged from year to year and from standard-giver to standard-giver (in regard to stochastic effects): 50mSv annual effective dose limit, and some sort of cumulative limit based on age or long spans of time. For deterministic effects, the upper shelf is three times as high, with 150mSv annual equivalent dose limit to lens of eye and 500 mSv annual equivalent dose limit to skin, hands and feet.

Infant Exposure
The ICRP in 1991 gives the following in Publication 60: a 2mSv equivalent does to the woman's abdomen once pregnancy has been declared and limiting intakes of radionuclides to about 1/20 of an ALI (annual limits of intake). This was the limitation to minimize embryo-fetus risk. As of 1993, the NCRP has presented a recommended figure of 0.5 mSv per month once pregnancy has been declared. Since I was born in 1994, I'm glad to know that standards had already been around for 30-40 years. With the rise of birth defects and radiation impacts on the lives of newborn children, more care has been taken to ensure that the likelihood of increased risk factors is minimized.

References
http://ncrponline.org/wp-content/themes/ncrp/PDFs/Kase_WKS_Address.pdf
http://www.asipp.org/reference2/NationalCouncilRadiation1993.pdf