Re: Airline personnel

["Ansari, Armin" <asa4@cdc.gov>]

Colleagues,



There is an excellent review article by John Boice on this topic.  I copied

the abstract below.  There are factors such as not having carried a

pregnancy or getting pregnant later in life that contribute to higher risk

factors for breast cancer among women.



There is also a recent article in American Journal of Epidemiology

2003;158(1):35-46, "Mortality from Cancer and Other Causes among Airline

Cabin Attendants in Europe:

A Collaborative Cohort Study in Eight Countries".



A Canadian study in Radiat Prot Dosimetry 2001;93(4):293-314, "Aircrew

Exposure from Cosmic Radiation on Commercial Airline Routes" may also be of

interest.



Here is John Boice's article in HP Journal:



*********************************************

Health Phys. 2000 Nov;79(5):576-84

Epidemiologic studies of pilots and aircrew.

Boice JD Jr, Blettner M, Auvinen A.



Abstact:

During flight, pilots and cabin crew are exposed to increased levels of

cosmic radiation which consists primarily of neutrons and gamma rays.

Neutron dosimetry is not straightforward, but typical annual effective doses

are estimated to range between two and five mSv. Higher dose rates are

experienced at the highest altitudes and in the polar regions. Mean doses

have been increasing over time as longer flights at higher altitudes have

become more frequent. Because there are so few populations exposed to

neutrons, studies of airline personnel are of particular interest. However,

because the cumulative radiation exposure is so low, statistical power is a

major concern. Further, finding an appropriate comparison group is

problematic due to selection into these occupations and a number of biases

are possible. For example, increased rates of breast cancer among flight

attendants have been attributed to reproductive factors such as nulliparity

and increased rates of melanoma among pilots have been attributed to

excessive sun exposure during leisure time activities. Epidemiologic studies

conducted over the last 20 y provide little consistent evidence linking

cancer with radiation exposures from air travel.

**********************************************



Regarding risk factors for breast cancer, see J Natl Cancer Inst.

1995;87(22):1681-5, "Proportion of Breast Cancer Cases in the United States

Explained by Well-Established Risk Factors".  The most significant risk

factor is later age at first birth and nulliparity which may place female

flight attendants at higher risk. 





Regards,

Armin





___________________________________

Armin Ansari, Ph.D., CHP

Radiation Studies Branch, EHHE, NCEH

Centers for Disease Control and Prevention 

1600 Clifton Rd, NE (MS-E39) 

Atlanta, GA 30333



Ph: 404.498.1837 Fax: 404.498.1811

AAnsari@cdc.gov