Flight crew, both in the cockpit and in the cabin, are occupationally exposed to varying levels of ionizing radiation. This situation has been formally acknowledged by the FAA since March 1990.
The primary sources of exposure are cosmic radiation from outer space and ionizing radiation from the sun. Occasionally, radioactive cargo may also be a source of exposure.
Our exposure to ionizing radiation increases with altitude and latitude. Given current understanding of the levels of exposure and its' potential impact on health, it is generally thought that only crew who spend substantial flight hours over 30,000 feet need to address this problem.
Female crew, planning a family, should learn as much as possible about their personal level of radiation exposure BEFORE becoming pregnant. Exposure levels should be discussed with a qualified health professional, when possible, before conception.