RAM Use by Pregnant Personnel

Yale University strives to keep the radiation exposure of every employee as low as practicable. The United States Nuclear Regulatory Commission (NRC) has an established basic exposure limit of 5 rems per year for all occupationally exposed adults. No clinical evidence of harm would be expected in an adult receiving this dose every year over a working lifetime. In the past, all Yale employees' exposures have been well below the 5 rem/year whole body exposure limit. In fact, in 1998 all whole body external exposures for radiation workers at Yale were below 0.5 rem/year or ten percent of the exposure limit and the majority of workers receive less than 10 mrem/year.

The developing fetus may be more sensitive to radiation than adults. Therefore, the National Council on Radiation Protection and Measurements (NCRP) has recommended that fetal radiation dose as a result of occupational exposure of the mother should not exceed 0.5 rem during the entire gestation period. The Nuclear Regulatory Commission concurs with this recommendation and therefore enacted the separate exposure limit for the embryo/fetus. According to NRC regulations, "The limit for the embryo/fetus of a declared pregnant woman is 0.5 rem over the entire gestation period." ¹ The NRC defines a declared pregnant woman as "a woman who has voluntarily informed her employer in writing of her pregnancy and the estimated date of conception." ² To help ensure the safety of the pregnant woman and her fetus, Radiation Safety is staffed with professionals who can assist pregnant women in evaluating their work requirements and exposure conditions. All pregnant women working with radioactive materials, or frequenting laboratories where radioactive materials are used, are encouraged to contact Radiation Safety for more information.

When a pregnancy is made known to Radiation Safety, a Health Physicist will review which radiation sources are approved for use in the woman's laboratory. The radiation exposure history of the worker will also be reviewed. If the review determines that iodinations are done in the laboratory or that high activity sealed sources and/or x-ray equipment are in use, the worker will be consulted. Recommendations will then be made on an individual basis.

According to Federal regulations, "It is the fundamental responsibility of the pregnant worker to decide when or whether she will formally declare her condition to her employer." ¹ If a woman chooses not to declare her pregnancy, Yale University is not required under the regulations to limit her dose to the 0.5 rem limit. However, "undeclared pregnant women are protected under the NRC regulations for all workers." ¹ The normal occupational dose limit of 5 rem/year would still be in effect, and the woman's dose would also have to be maintained as low as is reasonably achievable (ALARA). Any woman who has questions or concerns about declaring her pregnancy is strongly encouraged to contact Radiation Safety for a confidential discussion of this issue.

A provision does exist in the regulations so that an additional small incremental dose of 0.05 rem is available. This additional dose provides a "means of ensuring continued employment for the woman, and also removes the threat of inadvertent noncompliance." ¹ "The 0.05 rem dose increment is available as an additional dose if the embryo\fetal dose at the time of declaration is greater than 0.45 rem." ¹

The records required to be maintained under this policy will be protected from public disclosure because of their personal privacy nature. Yale University is required to maintain the records of dose to the embryo/fetus, with the records of dose to the declared pregnant woman. To assist the woman in declaring her pregnancy, the form on the next page may be used to notify both the Principal Investigator and Radiation Safety of a pregnancy. Notification will assist Radiation Safety in dose assessment and evaluation, and in making possible safety recommendations.

Any individual having questions related to the radiation protection of the embryo/fetus is encouraged to contact Radiation Safety. NRC Regulatory Guide 8.13, "Instruction Concerning Prenatal Radiation Exposure" and it's Appendix, "Questions and Answers Concerning Prenatal Radiation Exposure" are available to all persons at Yale who work with or frequent laboratories using radioactive materials or radiation producing devices. Please contact Radiation Safety, 135 College Street, for copies.

¹ Federal Register, Volume 56, No. 98, Tuesday, May 21, 1991, Rules and Regulations.

² Code of Federal Regulations, Standards for Protection Against Radiation - 10 CFR 20.1003