The
Basics
Cosmic radiation is the term used to describe the radiation that reaches us from other stars. Solar radiation is the term used to describe the radiation from our sun. Exposure to these forms of radiation is not much of an issue on the surface of the earth because the atmosphere serves as a protective layer. But when you are traveling at altitude, you have less of that protective layer above you and so your exposure to the radiation is higher.
There
are four factors that will affect your dose: (1) latitude; (2) altitude; (3)
time spent in flight; and (4) solar activity. There are three types of health
risks associated with in-flight exposure to cosmic and solar radiation: (1)
cancer; (2) genetic damage that might get passed on to a future baby (by men
and women); and (3) damage to the fetus.
The
activity of our own sun cycles and it usually peaks every 11 years. The last
peak was in 2000-2001. However, there was a rash of solar storms in Oct–Nov
2003 that included the strongest on record, during which the levels of solar
radiation increased by 1000 times in a matter of hours. Exposure during each
hour of flight during those storms was equivalent to having two to three chest
X-rays. This is a real concern for pregnant women. The airlines should post
warnings and allow pregnant women to postpone or cancel their trips without
penalty or discipline. Currently, there are no such requirements.
Unlike
in Europe, there are no radiation protections for crewmembers to inform them of
the possible health risks, monitor their estimated absorbed on-the-job
radiation dose, or offer options during pregnancy. Information is provided here
so that crewmembers can at least make an educated decision as to what level of
risk is acceptable.
Dec 2003 Cosmic and
solar radiation: facts for flight attendants and What has
the AFA done to learn more about the potential risks? Association of Flight
Attendants, AFL-CIO
Nov 2003 Study
on breast cancer risk among Icelandic flight attendants Research paper
by Rafnsson et al reported a significant increase in breast cancer risk among
flight attendants, even after adjusting
for reproductive factors.
Three-day GOES satellite proton
flux (solar storm) monitor
Useful real-time monitor to check for solar storms on same day, next day, and
previous day. If the green line on the chart exceeds 10 to the zeroeth power,
then pregnant women should postpone travel. Hosted by the Space
Environment Center, National Oceanic & Atmospheric Administration. For
comparison, see plots of solar activity during solar storms on Oct 28-31
2003 and Nov 5-7 2003
Nov 2000 Cancer incidence in California flight attendants Report
issued by the CA Department of Health Services (CADHS) Health Investigation
Branch & CADHS Occupational Health Branch.
Also published as: Reynolds P, Cone J, Layefsky M, et al. "Cancer
incidence in California flight attendants" Cancer Causes and Control, 13:
317-324 (2002). See also June 2001 Summary of CA
Department of Health Service report on cancer among AFA members
Association of Flight Attendants, AFL-CIO
Nov 25, 2003 New York
Times "Thanksgiving Forecast: Potential Fireworks on the Sun"
Nov 3, 2003 USAToday
"Second major solar storm slams into the Earth"
Nov 2003 Flight Safety
Information "Message to Congress Embedded in Huge Space Storm"
June 12, 2001 New York
Times "The Frequent Flier And Radiation Risk"
Questions and answers
about radiation exposure on commercial aircraft Health
Physics Society "Ask the Experts" feature
1999 The
Invisible Passenger: Radiation Risks for People Who Fly
(AFA-recommended book) Author Robert J
Barish PhD
1998 Summary
of article on exposure to in-flight radiation during pregnancy Author
DS Geeze
13 May 1996 Legislative
protections for European crewmembers Article 42 of Directive
96/29/EURATOM. Adopted by the Council of the European Union on 13 May 1996.
Member States required to implement the Directive by 13 May 2000. See also Implementation
of Article 42 in the United Kingdom
19 May 1994. Advisory circular (guidance
material) AC No. 120-61 Recommends that the airlines provide crewmembers
with educational materials that describe the potential radiation exposures and
associated health risks (Has been widely ignored.) US Federal Aviation
Administration.
5 Mar 1990. Advisory circular (guidance material) AC No. 120-52
Recognizes crewmembers as being occupationally exposed to radiation and lists
estimated radiation exposure levels according to flight route, assuming normal
solar activity. US Federal Aviation Administration.
Space weather alerts and displays Hosted by the Space Environment Center, National
Oceanic & Atmospheric Administration.
Space Weather Science news and information about the sun-earth
environment. Hosted by the National
Aeronautical & Space Administration