Section 64E-5.902 of Chapter 64E-5, FAC, requires that all individuals whose work may involve exposure to radiation be instructed in the health protection problems associated with exposure to radioactive material or radiation, in precautions or procedures to minimize exposure and in the regulations that they are expected to observe. This appendix describes the instructions that should be provided concerning biological risks to the embryo/fetus exposed to radiation, a dose limit for the embryo/fetus, and suggestions for reducing radiation exposure.
It has been known since 1906 that cells that are dividing very rapidly and are undifferentiated in their structure and function are generally more sensitive to radiation. In the embryo stage, cells meet both these criteria and thus would be expected to be highly sensitive to radiation. Furthermore, there is direct evidence that the embryo/fetus is radiosensitive. There is also evidence that it is especially sensitive to certain radiation effects during certain periods after conception, particularly during the first 2 to 3 months after conception when a woman may not be aware that she is pregnant.
It is important to note that the mother assumes all risk until she specifically declares her pregnancy, in a written and signed statement, to her Principal Investigator and copies the statement to the Radiation Control Officer. Upon receipt of the statement by the Radiation Control Office, the University and Principal Investigator is responsible for assuring that the female worker's exposure will not result in 500 millirem to the fetus. After a female occupational worker voluntarily notifies her Principal Investigator and the Radiation Control Officer in writing that she is pregnant and the estimated date of conception, for the purposes of fetal/embryo dose protection, she is considered a declared pregnant worker. Section 64E-5.311, FAC, places different radiation dose limits on declared pregnant workers than on adult workers. Specifically, for a declared pregnant worker who chooses to continue working as an occupational worker, the dose limit for the embryo/fetus from conception to birth (entire gestation period) is 500 mrem. Further, efforts should be made to avoid exceeding 50 mrem per month to the pregnant worker. It is the responsibility of the pregnant worker to decide when or whether to formally declare her condition. If a woman chooses not to declare her pregnancy, she will continue to be governed by guidelines for adult occupational exposure.
Because of the sensitivity of the unborn fetus, the National Council on Radiation Protection and Measurements (NCRP) has recommended that substantial variations in the rate of exposure be avoided to the unborn fetus from occupational exposure of the expectant mother and that special precautions be taken to limit the exposure of pregnant or potentially pregnant women. If the dose to the fetus is determined to have already exceeded 500 mrem when a worker notifies her Principal Investigator and the Radiation Control Officer of her pregnancy, the worker shall not be assigned to tasks where additional occupational radiation exposure is likely during the remainder of the gestation period.
Instructions on radiation risks should be provided to workers, including supervisors, in accordance with 64E-5.902 before they are allowed to work with radioactive materials and/or radiation producing devices or access to such areas. In providing instructions on radiation risks, employers should include specific instructions about the risks of radiation exposure to the embryo/fetus. The instructions should be presented both orally and in printed form, and the instructions should include, as a minimum, the information provided in Attachment 2 to this Appendix. Individuals should be given the opportunity to ask questions and in turn should be questioned to determine whether they understand these instructions.