Considerations Regarding Flying and Pregnancy
by Captain Joyce May

Hopefully by now you are more appraised of some of the concerns that air crewmembers face as the result of the cosmic radiation we encounter at our normal jet cruising altitudes in the course of our work (see the article in the April/May/June 2000 issue of Flightline entitled “AIRCREW RADIATION EXPOSURE: DO YOU KNOW THE RISK?”). Admittedly, the problem of aircrew radiation exposure is complex and not an issue most of us care to think about. Just the same, the problem is a real one and not likely to be properly addressed without a demand from those most affected by the problem—the air crewmembers.

The risks incurred for most crewmembers are accumulated over the course of years of working in this profession and the long-term exposures are readily manageable by the type of flying that is done. Long-haul flying (transcons and longer) and routes traversing regions closer to the poles (European and Asian route structures) have significantly higher radiation dosages per flight than, say, flights from the U.S. to the Caribbean, or flights within the U.S. that have intermediate leg stops at a hub, as examples. Unfortunately, as yet, no monitoring program has been established by our government, despite their admission of our status as occupationally-exposed radiation workers. While your union is seeking to remedy this situation, the onus is presently on you to calculate and monitor your own radiation exposure levels. The best tools which currently exist for your use is a computer modeling program set up by the FAA’s Civil Aeromedical Institute (http://www.cami.jccbi.gov/AAM-600/Radiation/600radio.html) or your purchase of a personal dosimeter badge
(call 212-459-2107 or email joycemay@gateway.net for more information).

A more critical situation exists, however, when it comes to the issue of flying and pregnancy. By now all crewmembers have received information from the American Airlines Medical Department regarding flying and pregnancy. Flight attendants received individually sent mailers, and a copy of the same notice is in the Third Quarter 2000 issue of The Flight Deck for the edification of the pilots and is also on the AA and APA websites. It is very important that air crewmembers heed the advice given in this notice from our medical department and call the hotline number as soon as she suspects that she may be pregnant. This is because that while the levels of radiation exposure received at jet cruising altitudes is significant for all crewmembers; they do not pose an immediate threat or hazard. The potential health hazard for crewmembers is generally a more long-term exposure hazard—except in the case of the pregnant crewmember. The fetus is much more sensitive to the effects of radiation and cannot tolerate the doses that an adult can without incurring harmful effects to its health and well-being. The dose limits recommended by the National Council On Radiation Protection and Measurements, as well as the International Commission on Radiological Protection (the two main organizations who set such standards) have accordingly set lower exposure limit recommendations for pregnant versus non-pregnant women with the health of the fetus in mind. With many of the typical flight schedules that air crewmembers fly here at AA, it is likely that after just a few months of flying a normal schedule, a fetus would by then have already exceeded its recommended dose of radiation.  We also happen to be currently in the middle of a period of increased solar flare activity. These flares are normally infrequent, but during a flare (which usually lasts anywhere from a few hours to a few days) radiation exposures can be significantly increased at jet cruising altitudes to the point where the recommended exposure level to the fetus can be exceeded in a single month, or even on a single long-haul flight. Most physicians are unaware of this hazard and typically and erroneously advise a pregnant woman concerned about flying that it’s O.K. to do so. The hotline that AA Medical has set up was established in part to dispel any misinformation that a crewmember’s obstetrician may have on this issue. This will hopefully ensure that a woman’s decision as to whether or not to continue to fly during her pregnancy is based on sound information considering her flying schedule, routes, and other information pertinent to her unique situation. For most air crewmembers at AA, immediate medical leave is the most prudent course of action for the health of her unborn child.

To provide more background on just why radiation is so detrimental to a fetus, it may help to recall that the reason that radiation is effective in treating cancer patients is because cancer cells are rapidly dividing cells. All rapidly dividing cells are sensitive to radiation and are much more easily destroyed by radiation than more slowly dividing cells are. Since a fetus’ whole body consists of rapidly growing, rapidly dividing cells, a given dose of radiation will kill-off a much higher percentage of cells in a fetus than in an adults’ body of more slowly dividing cells. If enough radiation exposure is received early in pregnancy, this could even cause sufficient damage to the embryo to result in a miscarriage, possibly even before the pregnancy was known.  Fertility problems in flight attendants have already been identified, with radiation exposure mentioned as one of several likely causes. Radiation exposure to the fetus is the most critical in the first trimester of a pregnancy when the major organs of the child’s body are forming. Indeed, it has been documented that a high dose of radiation received between the eighth and fifteenth weeks of gestation when the brain is forming has resulted in cases of mental retardation in the child. The amounts involved to cause this effect are many times higher than the doses that could normally be expected to be encountered by an air crewmember, but it does raise the question as to what less obvious degradation in development a child may incur from the lower levels more likely to be received at jet cruising altitudes.  It has also been shown that early exposure to radiation, whether it be as a fetus or an infant slightly increases the child’s normal likelihood of developing cancer at some point in his or her life by 0.1% per 10 mSv of exposure. 10 mSv is on the high side of what is a likely dose for a fetus to receive during gestational exposure from the activities of its aircrew mother, but is not out of the question when considering solar flares. Developmental detriments to the unborn child is probably the greater of the risks.

Your union is continuing to work on getting the issue of aircrew radiation exposure properly addressed.  We are not the first to try to get this issue to receive the attention it rightfully deserves but there are many obstacles to overcome in doing so. Your support of this issue is vital to our success.  Voice your concerns to your Chief Pilot and encourage your fellow crewmembers to do the same.

Feel free to direct any questions you may have on the issue of aircrew radiation exposure to Captain Joyce May at joycemay@gateway.net or to (212)459-2107.

REFERENCES:

Nicholas, J.S., Copeland, K.A., Duke, F.E., Friedberg, W., O’Brien K. Galactic Cosmic Radiation exposure of Pregnant Flight Crewmembers.  Aviation, Space, and Environmental Medicine, Vol. 71 No. 6, June 2000.

National Council on Radiation Protection and Measurements, Limitation of Exposure To Ionizing Radiation. NCRP Report No. 116, March 31, 1993.

National Council on Radiation Protection and Measurements, Radiation Exposure and High-Altitude Flight. NCRP Commentary No. 12, July 21 1995.

May, J.A., Standifer, R., Aircrew Radiation Exposure: Do You Know The Risk?, Flightline, April/May/June 2000.