Bringing Radiation Exposure to Flight Crews and Frequent Fliers into
the Spotlight
By Karen Calomino, MS
It is well known that ionizing radiation affects our health in many ways and can cause both acute and
delayed symptoms such as cancer. However, although crewmembers and frequent fliers are exposed to
large amounts of radiation on long-haul flights, they have been left in the dark. The US airline industry
has ignored the topic for quite some time despite the fact that the International Commission on
Radiological Protection classified flight crews as “radiation workers” over 20 years ago (ICRP, 1991) and
the FAA agreed that, “air carrier aircrews are occupationally exposed to ionizing radiation” in 1994
(Barish, 2009). These statements justify an exposure limit up to 50 times more than the general public,
and while flight crews are estimated to receive one of the highest average doses of any occupationally
exposed group in the U.S. (Goldhagen, 1998) including workers at nuclear power plants (Barish, 2001),
there are no regulations in place protecting them.
In addition to radiation, crewmembers and passengers are exposed to many other toxins on planes,
including flame retardant chemicals, pesticides, and pathogens. Last year, through the implementation
of section 829 of the FAA Modernization and Reform Act of 2012, OSHA now enforces the standards
pertaining to blood-borne pathogens, hazard communications, and hearing conservation of
crewmembers. The subject of radiation however is still governed by the FAA, which in its latest
crewmember training Advisory Circular suggests outdated reading materials and links (FAA, 2006). As a
crewmember myself, my career of flying mainly long-haul international routes across the polar region,
along with recent discoveries of my health including a high amount of oxidative stress and an inflamed
mucosal barrier, has brought this subject close to home and has resulted in the need to learn more
about the amount we are exposed to and the detrimental effects it can have on us. I find it unacceptable
that crews and passengers are neither educated nor protected from high exposure doses.
Since 2000, airlines operating in the countries of the European Union are required to limit aircrew
member’s exposure to cosmic radiation (CAA, 2013). In the U.S., the Nuclear Regulatory Commission’s
Code of Federal Regulations require that individuals exposed to radiation receive adequate training to
protect themselves and state that these individuals have the right to know how much radiation they
have been exposed to (NRC, 2013). The FAA on the other hand only recommends that airlines educate
their employees about the risks involved. Since it is not a required action, airlines do not feel the need to
inform them. I barely remember receiving one notice in my 25-year career explaining the effects that
radiation could have when flying while pregnant. The concluding remarks stated something to the effect
that it would be impossible to determine that a disease resulted from radiation exposure and that is
important to keep the risks associated with flying in perspective with other risks that are related to
chronic diseases. Other than that I have heard nothing. When questioning other flight attendants and
pilots about this, I received similar answers. Most are aware of cosmic radiation but not the extent of it
and many feel that there is nothing we can do.
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Now, more than ever is awareness imperative for several reasons:
The majority of flight attendants and pilots fly until they retire at around 65, resulting in a greater
cumulative effect of radiation.
Cross-polar traffic, where radiation levels are the highest, is continuously increasing. In 2011, there
were 10,993 one-way crossings (Meehan, 2012).
The sun is nearing the maximum point of its 11-year cycle with solar activity expecting to peak now
in 2013. This could result in huge increases in radiation during flights.
Apparently it is a U.S. legal requirement that those who are occupationally exposed to radiation
knowingly and willingly accept this increased level of risk (Barish, 2001), however rather than attempting
to educate flight crews and implement strategies to limit levels of radiation, airlines are expecting crews
to work longer hours each month, which ultimately results in more exposure.
Everyone is exposed to ionizing “background” radiation
Energy emitted from a source is generally referred to as radiation. Ionizing radiation has enough energy
to remove tightly bound electrons from an atom, causing it to become charged or ionized. It affects
health when it results in changes in the cells of the human body by breaking the chemical bonds in
molecules. This type of radiation can occur in waves, such as gamma radiation and x-rays that penetrate
deeply into tissue, or as particles, such as alpha particles, beta particles, and neutrons.
When determining health effects of radiation, its dose is measured in “sieverts” (replaces the “rem”), or
millisieverts (mSv). This measures the “effective dose”, which is a more accurate representation when
exposure is limited to one or several body part(s). As an example, a typical chest x-ray involves about 0.1
mSv of radiation exposure, however since it is limited to the chest area, the “effective” dose is only
about 0.02 or 0.03 mSv because only the lungs and breasts are exposed to the radiation (Blue, 2000;
European Commission, 2000; FDA, 2002; Roguin & Nair, 2007; Shulman, 2008; FDA, 2009). Exposure to
cosmic radiation on the other hand affects the whole body, so the “effective” dose is equivalent to the
exposure amount (Blue, 2000).
Cosmic radiation is a naturally ionizing form of radiation that consists of two parts: 1) a permanent
component consisting of highly charged particles ejected from the galaxy, or galactic cosmic rays (GCR)
and 2) sporadic particles, or solar energetic particles (SEP), that are associated with eruptions on the sun
and which varies in intensity according to the sun’s 11-year cycle. The two barriers that protect Earth
(the planets magnetic field and the Earth’s atmosphere) decrease the amount of cosmic radiation that
reaches the ground, however people will always be exposed to low levels of this as well as other
naturally occurring sources of ionizing radiation including radon gas and radioactive elements found in
the air, water, rocks, and minerals. Combined, this naturally occurring “background radiation” exposes
people in the U.S. to an average effective radiation dose of about 3 millisieverts (mSv) per year. Manmade sources, including diagnostic x-rays and nuclear medicine add an additional 3 mSv per year
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(Bushberg, 2009). The total can of course vary from person to person depending on their location
(higher altitude cities such as Denver have more cosmic radiation) and their medical imaging history.
Why is the radiation dose limit for airline crews set so high?
The National Council on Radiation Protection and Measurement (NCRP), and the International
Commission on Radiological Protection (ICRP) offer recommendations for the maximum permissible
dose (MPD) of radiation that people should be exposed to. These in turn are usually adopted by
government regulatory agencies including the FAA, EPA, and NRC. Both the NCRP and the ICRP agree
that the “general public” should not be exposed to more than 1 mSv (equivalent to an effective dose of
about 50 chest x-rays) above the average background and medical radiation per year. In its’ Report No.
116, the NCRP states that the effective dose limit is 1 mSv for members of the public “who are exposed
continuously or frequently”, however on an “infrequent” basis (not likely to occur often in an
individual’s lifetime), the annual effective dose may go up to 5 mSv (2004). The ICRP recommendation is
based on the assumption that there is no safe level of exposure, that even the smallest exposure has
some probability of causing a stochastic, or long-term effect, such as cancer, and that doses rising above
1 mSv per year will justify protective actions for members of the public (Butler & Cool, 2010).
And then there are those who are occupationally exposed to radiation. The ICRP recommended limit for
an occupationally exposed person is a 5-year average of 20 mSv per year with no more than 50 mSv in a
single year and the NCRP recommends 50 mSv per year with a maximum permissible dose of 10 mSv
times the person’s age (Friedberg & Copeland, 2011). The FAA follows the recommendation of the ICRP.
If they had followed the recommendation of the NCRP, a commission chartered by the U.S. congress in
1964, crewmembers maximum permissible annual dose would be less since it is quite common that
crewmembers have long careers. As an example, a flight attendant with a 40-year career who retires at
age 65 would have had an average annual permissible dose of about 16 mSv (10 x 65 = 650, 650/40years
= 16.25 mSv/year) Recommendations for pregnant crewmembers are much less with a dose limit of
about 1 mSv for the remainder of the pregnancy or 0.5 mSv in any month (Friedberg & Copeland, 2011).
With regards to frequent flying passengers or other travelers, there are no legal limits since this is
considered a “voluntary” activity (HPS, 2011).
I was curious to find out why the recommended annual dose limit for crewmembers was set so much
higher than the general public. I understand that the nature of the job comes with some risks, however
20 to 50 times the limit of other US citizens? After all, we are made up of the same types of cells.
Perhaps they think we are super-heroes and can withstand these levels much better?
According to the NCRP, one of the goals of radiation protection is “to prevent the occurrence of
clinically-significant radiation-induced deterministic effects by adhering to dose limits that are below the
apparent threshold levels (2012).” Deterministic effects are usually based on acute exposures and are
mostly the result of death or malformation of cells. Apparently the ICRP selected an occupational dose
limit that “falls just short of unacceptable” before detrimental effects may occur (Butler & Cool, 2010).
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The NCRP and ICRP have two other fundamental principles for limiting the doses received by people:
justification and optimization. Justification requires that any decision that alters the radiation exposure
situation should result in sufficient individual or societal benefit to justify the risks involved.
Optimization is based on maintaining all exposure levels “as low as reasonably achievable” (also know as
the practice of ALARA). These features are based on the linear, non-threshold (LNT) hypothesis, which
assumes that any radiation exposure, no matter how small, carries with it a level of risk that is
proportional to the level of exposure. So since there is no safe level and increases in exposure result in
incremental increases in stochastic (or long-term low-level exposure) risks until a threshold level is
reached that has been known to cause deterministic (acute) radiation symptoms, exposure should be
justified and kept as low as reasonably achievable.
According to a senior Health Physics Advisor with the NRC, optimization, or the ALARA practice, is more
important than setting dose limits (Sherbini, 2000). The Health Physics Society also states that this
philosophy results in occupational doses that are much lower than the allowable limits and that the
average annual effective dose for all occupational workers in the U.S. is less than 5 mSv (Chabot, 2012).
How much ionizing radiation are we talking about?
Crews and passengers can be exposed to additional ionizing radiation from several sources including:
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Galactic cosmic radiation
Solar radiation
Dark lightning
Radioactive cargo and security scanners
Galactic cosmic radiation
The radiation dose received from galactic cosmic rays is affected by four main factors: time spent flying,
altitude, latitude, and solar activity. Since radiation is cumulative, the more you fly, the more radiation
you are exposed to. In addition, exposure is more intense at higher altitudes as well as higher latitudes.
This is because the thinning of the atmosphere at higher altitudes provides less protection, and
electrically charged radiation particles are drawn toward the Earth’s north and south magnetic poles. A
normal cruising altitude of about 39,000 feet brings the total radiation levels to about 64 times greater
than at sea level (Science Daily, 2005), and the exposure rate is about four times as much at 70 degrees
north or south latitude than 25 degrees (Blue, 2000). So long-haul flights over the polar routes are
exposed to a lot more radiation than those flying at mid-latitudes. The final factor is solar activity.
Depending on whether the sun is at a solar minimum or maximum (which varies throughout an 11-year
cycle), the amount of cosmic radiation can change. At the solar minimum there is less of a shield due to
few sun spots so galactic radiation can double. On the other hand, when the sun is at the solar maximum
with many sun spots, this may decrease the amount of galactic radiation that gets through.
The FAA has developed a program called CARI that can either be downloaded or used directly from the
Web site (jag.cami.jccbi.gov/cariprofile.asp). It calculates the effective dose of cosmic radiation received
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by those flying between two airports in the world, however the program does not take into account the
increased radiation caused by solar flares. I utilized this program to determine radiation exposure on
long-haul flights flying over the polar region at an altitude of 38,000 feet during 05/2013.
The radiation exposure for a flight from Chicago to London was estimated to be 0.055 mSv. To put this in
perspective:
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One roundtrip is equivalent to the effective dose of approximately five and a half chest x-rays
Five roundtrips, or a months worth of flying for full-time crewmembers, is equivalent to being
exposed to the effective dose of about 27 chest x-rays.
A full year of flying, or about 1000 hours, exposes crews to almost 7 mSv, which is equivalent to
the effective dose of approximately 350 chest x-rays.
The annual exposure from just galactic radiation on this flight exceeds the annual average
effective dose for all occupational workers in the U.S. (Chabot, 2012).
Ten round trips (or two months of flying for crews) exceed the annual recommended dose limit
for the general public.
Also, according to the CARI program, a one-way trip from Chicago to Shanghai is estimated to expose
individuals to 0.091 mSv, which is the equivalent of about four and a half chest x-rays each direction.
Crews or frequent fliers are exposed to more than the annual recommended amount for the general
public after six round trips. Crews flying three trips a month or about 1000 hours per year may also
reach an annual exposure amount of almost 7 mSv. A flight from Los Angeles to London is estimated at
0.071 mSv, and New York to London is estimated at 0.04 mSv.
Passengers and crews on a flight from New York to Hong Kong are exposed to about 0.1 mSv (or the
effective dose of five chest x-rays each way). Five roundtrips could exceed the maximum dosage
guidelines for the general public (Crampton, 2001).
Reports on pilot exposure to radiation agree that there is a high-exposed group of pilots who may
exceed 7 mSv per year (Graweski et al., 2011).
Coast-to-coast flying exposes people to less cosmic radiation since they do not fly over the polar routes.
A round-trip flight from San Francisco to New York is the equivalent of about two and a half chest x-rays,
or 0.05 mSv. Twenty round-trips reach the limit for the general population (Drucker, 2002).
Solar radiation
Although cosmic galactic radiation may be down slightly during solar maximums, there is the possibility
for solar storms, which may result in large amounts of radiation from the sun. The storms are a result of
an explosive release of energy from the sun in the form of solar flares and coronal mass ejections. Solar
particle events (SEP) are intense flows of radiation from the sun made up of protons and charged
particles that are associated with these eruptions. They are rated on a scale from S1 (minor) to S5
(extreme) according to the amount of very energetic and fast solar particles that move through a given
space in the atmosphere. Flights that rely exclusively on radio communications, such as those routed
through the poles, may be re-routed during a an SEP event since it can disturb the regions through
which high frequency radio communication travel (Fox, 2012). Passengers and crews may be exposed to
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a radiation risk during storms that are rated S2 (moderate) or higher (NOAA, 2005). These solar flares
can increase the radiation exposure level by a factor of 10 or 20 and can last anywhere from a couple of
hours to a couple of days. Each possible solar particle event may add an additional 1 mSv per flight to
the cumulative galactic cosmic radiation effective dose (Beck et al., 2009) and could add up to a lifetime
neutron dose of 46 mSv (Graweski et al., 2011). Anyone that happens to be working on one of those
flights might be exposed to the equivalent of 50 chest x-rays or more. If a storm is rated as an S-5 on the
center’s scale, which is the most extreme, exposure can be equivalent to 100 chest x-rays (Crampton,
2001).
Flares are based on a classification system that groups them according to their strength. The smallest
one is classified as A, followed by B, C, M and X. Each letter represents a 10-fold increase in energy
output so an X flare is ten times greater than an M flare and 100 times greater than a C. In addition,
there is a finer scale from 1 to 9 for the A through M flares. The X-class flares can go higher than this.
Although it is the last letter, there are flares that are more than 10 times stronger than an X1. During
2003, during the last solar maximum, the most powerful flare cut out the sensors measuring it at X28
(Fox, 2011).
The sun is now once again nearing the maximum point of its current cycle. 2013 was expected to be a
tumultuous year (Wrenn, 2012; Mosher, 2011) and that seems to be holding true. So far there have
been quite a few flares in the last few months and toward the end of the year, there could be several a
day (Palmer, 2013). The cycle, called Solar Cycle 24, started in 2008 and is expected to run until 20192020 (Malik, 2013). The last peak was in 2000-2001 but included solar storms in Oct-Nov 2003, during
which the levels of solar radiation increased by 1000 times in a few hours (AFA-CWA, 2010), as well as
solar proton events. One event measured by NASA resulted in a solar cosmic radiation dose of 0.35 mSv
per hour, or the equivalent dose of over 17 chest x-rays an hour (Copeland et al., 2008).
The first X-class flare of the current cycle was on February 15, 2011 (X 2.2) Since then, there have been
another 15 X-class flares (NASA, 2013) These include:
August 9, 2011 – The strongest flare so far at X 6.9
March 7, 2012 – The second strongest flare so far at X 5.4. On flights from Chicago to Stockholm,
the radiation exposure was 0.251 mSv (about 13 chest x-rays) and from Chicago to Beijing it was
estimated to be 0.365 mSv (about 18 chest x-rays) (Meehan & Kunches, 2012).
May 12-13, 2013 – Three solar flares occurred within 24 hours. They measured X 1.7, X 2.8, and X
3.2. All of them were associated with coronal mass ejections (Fox, 2013).
Dark Lightning
In addition to cosmic radiation, we might be exposed to radiation from thunderstorms that produce
electrical breakdowns called “dark lightning”. This phenomenon can emit large amounts of gamma-rays,
called Terrestrial Gamma-Ray Flashes, or TGFs, in the process. If flying near the tops of these electrified
storms, the radiation doses are equivalent to 1 mSv, or a year worth of recommended radiation for the
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general public. And near the middle of the storms, the radiation dose could be ten times larger, roughly
equal to a full-body CT scan (Florida Institute of Technology, 2013).
Radioactive cargo and security scanners
A Nuclear Regulatory Commission study estimated that the average annual radiation dose to
crewmembers from radioactive cargo is about 0.3 mSv (FAA, n.d.), which is equivalent to an additional
15 chest x-rays. With regards to backscatter scans at airports, a single scan expose people to about 0.1
microsieverts or about 0.0001 mSv. Approximately 200 scans are equivalent to one chest x-ray and
10,000 are equivalent to the recommended yearly dose of radiation for the general public (Shauer,
2011). While the dose per scan is very low, every little bit of radiation adds to the total cumulative
amount that crewmembers and frequent fliers receive. It is interesting to note that x-ray technology is
not an authorized method of screening at EU airports. This was implemented to protect the health and
safety of their citizens (European Commission, 2011).
Evidence that ionizing radiation is a significant health risk to crewmembers and
frequent flyers
Ionizing radiation is a well-known carcinogen that produces highly reactive free radicals (by stripping
away electrons from atoms) that can damage the DNA, lipids, and proteins, and lead to unnatural
chemical reactions in cells. Once damage occurs at the cellular level, and the body is unable to repair or
replace the damaged tissue, an uncontrolled growth of cancer cells or mutations in the DNA may occur.
Radiation to just about any organ can have both acute and chronic adverse effects, however they differ
in their radiosensitivity. According to the Merck Manual for Health Care Professionals (Bushberg, 2009),
the top six most critically affected tissues include:
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Lymphoid cells (cells responsible for the production of immunity-mediated cells or anti-bodies)
Reproductive cells (ovum or sperm cells)
Bone marrow cells (cells that makes other blood cells)
Intestinal epithelial cells
Epidermal stem cells (thin, outermost layer of the skin)
Hepatic (liver) cells
Breasts, thyroid glands and eyes are also extremely sensitive to the cancer-causing effects of radiation
(NAS, 2005).
There are many studies done on the adverse health effects from acute radiation poisoning. The effects
of doses less than 100 mSv spread out over long periods have been difficult to track, however recent
scientific studies are unveiling detrimental effects at these lower doses as well. This is largely due to
increasing incidences with increasing times after exposure. There is now available data from atomic
bomb survivors with 40-50 year follow-ups using a newly implemented dosimetry system, from studies
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of people exposed to radiation for medical reasons, and studies of nuclear workers exposed at low doses
and dose rates (NAS, 2005).
In 2006, the FAA canceled their 1994 Circular and replaced it with a new one that states, ‘The likelihood
of developing cancer because of occupational exposure to galactic radiation is a small addition to health
risks experienced by the general population. Currently, it is not possible to establish that an abnormality
or disease in a particular individual resulted from exposure to galactic cosmic radiation at the doses
likely to be received while flying.” (FAA, 2006). After finding an extensive amount of information that
indicate otherwise, this statement is not very convincing.
The National Academies of Science released a 700-page report on the risks from ionizing radiation in
2005, in which it was confirmed that there is no safe level of exposure and that even very small amounts
can cause cancer. In the study, low doses were defined as those ranging from nearly zero to about 100
mSv. According to the report, the risk of getting cancer from radiation is increased by about a third from
current government risk figures. The numbers estimate that 1 in 100 members of the public would get
cancer if exposed to 1 mSv per year for a 70 year life-time (NIRS, 2005). Crewmembers can be exposed
to more than 7 times this amount per year from galactic radiation alone throughout their career
(estimated using the FAA computer program CARI-6).
A recent 15-country study of cancer risk among radiation workers in the nuclear industry confirmed a
“significant association” between radiation dose and all-cause mortality (Cardis et al., 2007). Keep in
mind that crewmembers are exposed to more radiation than nuclear plant workers. Also, cancer studies
from 2002 to 2007 provide evidence that “cancer risk factors for occupational exposures are not lower
than for atomic bomb survivors.” This is based on low-dose-rate, moderate-dose exposure to the order
of 100 mSv. (Jacob et al., 2009). Crews can easily be exposed to this from galactic radiation alone flying
15 years of regular-scheduled polar flights (7 mSv times 15years). According to the American College of
Radiology, a linear increase of cancer risk at doses in excess of 50 mSv has been directly observed by
epidemiological research (Picano et. al., 2007). Crews can be exposed to this after only seven or eight
years. And according to the NCRP, there is a consistent body of evidence for the carcinogenicity of
ionizing radiation in humans. Absorbed doses of less than 200 mSv have been associated with leukemia,
and cancer of the thyroid, breast, and lung (NCRP, 2011). Crews can easily be exposed to this from
galactic radiation alone flying 30 years of regular-scheduled polar flights.
Recently, more data have surfaced that reveal other adverse health effects from chronic low doses of
radiation. In a 2011 report, the ICRP described the detrimental effects of low-dose radiation on the
development of cataracts, circulatory disease, and immune dysfunction. As a result of a study on
radiation-induced cataract (Jacobs et al., 2011), the ICRP revised the occupational annual dose limit that
was considered safe for the eyes from 150 mSv to 20 mSv. In addition, they also suggested lowering the
threshold dose for circulatory disease after evidence of higher incidence of injury than expected at lower
doses and described in detail the effects of radiation on the lymphatic tissues and the bone marrow,
which are an important part of the immune system (ICRP, 2011). In one study, significant immunological
effects were observed in those who were exposed to low-dose radiation (Chang et. al., 1999).
It will be interesting to see future studies on the effects low-dose, long-term radiation exposure on the
intestinal lining. According to the Merck Manual, as well as many other sources, this tissue is extremely
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sensitive to ionizing radiation (Barnes, 1999, p. 101; Macnaughton, 2000; Nejdfors, et al., 2000;
Thiagarajah, et al., 2000; Monti, et al., 2005; Francois et al., 2013). One recent study has already
revealed that doses as low as 10 mSv may induce apoptosis, or death of cells, within the lower crypt of
the small intestine (Umar, 2010). The lower crypt is part of the mucosal barrier (or lining) in our gut that
protects us against pathogens from the external environment while at the same time ensuring we get
nutrients from foods. Once the lining breaks down, a magnitude of adverse health effects may follow
including leaky gut and malabsorption of nutrients.
The thyroid is also very sensitive to ionizing radiation. A study in 2005 concluded that occupational
exposure to ionizing radiation is related to the risk of developing an autoimmune thyroid disease and
that “the usage of thyroid protection shields by radiation workers is strongly recommended.” (Volzke et
al., 2005).
Most studies that have been performed on crews researched the incidence and risk of cancer among
pilots and flight attendants. Although it is difficult to pinpoint the exact cause, the two cancers that are
consistently higher among crews are melanoma and breast cancer (Badrinath et al., 1999; Gundestrup &
Storm., 1999; Rafnsson, et al., 2000; Rafnsson et al., 2001; Pukkala et al., 2002; Reynolds et al., 2002; Ott
& Huber, 2006; Hammer et al., 2009; Sykes et al., 2012). Nearly 20 epidemiologic or similar studies of
cancer incidence was published between 2000 and 2004, with many reporting increased risks of breast
cancer among flight attendants and melanoma among pilots and flight attendants (Sigurdson & Ron,
2004). Studies have also shown pilots to have an increased risk of prostate cancer and myeloid leukemia,
which is the type of leukemia induced by exposure to radiation (Band et al., 1996; Gundestrup & Storm,
1999).
In 2005, a review was initiated to determine if ionizing radiation could be a cause of melanoma. The
study analyzed seven groups including nuclear workers, survivors of atomic bombings of Japan,
recipients of medical radiation, and airline crews. Relative risks for leukemia were used to confirm the
likelihood of exposure to ionizing radiation. Generally, the categories with elevated relative risks of
leukemia had proportionately elevated relative risks of melanoma which suggests that people exposed
to ionizing radiation may be at increased risk of developing melanoma (Fink & Bates, 2005).
A 2006 study proved that breast cancer increased by 40% among flight attendants and stated, “female
flight attendants and women who fly frequently should be informed of this potential increase in risk.”
(Salhab, & Mokbel). A meta-analysis that same year stated in its conclusion, “ …all airlines should, as
some companies do, estimate radiation dose, organize the schedules of crewmembers in order to
reduce further exposure in highly exposed flight attendants, (and) inform crew members about health
risks…” (Buja et al., 2006).
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What can we do about it?
As the meta-analysis from 2006 suggests, airlines should monitor radiation dose and educate crews of
the risks involved. Airlines operating in the European Union are required to keep their crew’s annual
effective dose under 6 mSv, airlines in Japan try to keep their crew’s exposure under 5 mSv, the Nuclear
Radiation Commission require that employees are educated about the health effects of radiation, and
health care professionals are recommended to wear dosimeter badges if they are at risk for exposures
great than 5 mSv (Bushberg, 2009). The U.S. airlines, on the other hand, neither educate their
employees on radiation nor monitors the amount received. Although some unions have expressed
concerns about the risks to crewmembers and passengers, the U.S commercial aviation community
seems to disagree (Fisher & Jones, 2007, p. 32).
U.S. airlines do receive solar storm reports from the NOAA National Weather service (NWS), however
when I asked several captains about these, most knew they were available but stated that they did not
often see them in their briefings. A workshop was developed early 2007 (that included participants from
the aviation community, federal government, and space weather community) after space weather
storms in 2003, early 2005, and in the fall of 2006 demonstrated a growing need for discussion of the
use of space weather forecasts. It was felt that the airlines’ “overly cautious response” to these storms
showed “a lack of understanding and awareness” and highlighted “the lack of globally accepted and
coordinated operational information and awareness (p. 3).” It was also pointed out that since “there is
little understanding of space weather, there is little perception of the risks (p. 26).” There was a need to
provide education at all levels (including dispatchers, ATC, pilots, crew, and passengers) and a need to
make the space weather reports less technical and more easily understood (Fisher & Jones, 2007). That
was 6 ½ years ago. Then, in April 2012, the same thing repeated itself. Another workshop brought
together the same group of people (aviation industry representatives, regulators, and space weather
forecasters) with the same conclusions; Space weather information should be communicated “in a
manner emphasizing applicability, readability, and dispatcher comprehension”, and that “education is
essential at all levels: dispatchers, air traffic control, pilots, crew, and passengers …” (Meehan &
Kunches). Back in 2007, the airlines were “trying to understand why they should care about space
weather.” Today, when the solar cycle is at its peak, it appears that this is still the case. In its 2006
Advisory, the FAA states that as long as air carriers respond to solar radiation alerts, ionizing radiation
from the sun should not contribute enough radiation to exceed recommended exposure limits. But
unless airlines understand about and agree that these storms can have significant effects on
communications and the health of crews and passengers, how can they respond appropriately?
NASA is currently trying to build a better model called NAIRAS (Nowcast of Atmospheric Ionizing
Radiation for Aviation Safety) that can predict the amount of both solar and cosmic radiation that flight
crews and frequent fliers are exposed to on commercial airline flights. According to them, this model
tracks individual aircrew exposure levels, provides airlines and FAA with necessary data to develop
procedures for radiation exposure limits, provides time-critical data during solar particle events, and
provides a database of radiation exposure levels. By implementing this system, airlines can balance the
cost of changing flight paths against minimizing radiation exposure and health risks to crews and
passengers (Mertens et. al., 2008).
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Until all airlines decide to implement strategies that minimize risks, there are a few things we can do
ourselves.
1. Stay informed of solar events prior to trips and keep track of radiation levels through FAA, NOAA,
and NASA websites:
http://jag.cami.jccbi.gov/cariprofile.asp
FAA system (CARI-6) that calculates effective dose rates from galactic radiation (past months)
http://www.swpc.noaa.gov/rt_plots/pro_3d.html
NOAA Space Weather Prediction Center’s 3-day solar particle event chart. Particles greater than
100 PFU are considered moderate (S2 rating) and may expose passengers and crews to an
elevated radiation risk.
http://www.swpc.noaa.gov/
NOAA Space Weather Prediction Centers website with current space weather conditions. If you
click on “Alerts/Warnings”, then “email registration”, you can sign up for free SPE alerts.
http://sol.spacenvironment.net/~nairas/
NASA’s NAIRAS prototype that provides real-time predicted radiation dose rates. Click on
“current rate dose” to get daily updates on four cross-polar routes: London-New York, ChicagoStockholm, Chicago-Munich, Chicago-Beijing. This gives you an estimate of total radiation
exposure in an easy-to-understand format.
NASA has also developed space weather apps for the iPhone (SpaceWx) and Android (NASA
SWx).
2. Other Suggestions:
Eliminate as many toxins from other sources as possible so that our liver does not become
overburdened. The more congested our liver is, the harder it will be to breakdown and eliminate
toxins created by radiation.
Increase antioxidants with fruits, vegetables, and supplements. Antioxidants fight free-radicals by
contributing electrons to unstable molecules created by radiation. Studies suggest that foods
high in vitamins C and E, beta-carotene, beta-cryptoxanthin, and lutein may protect against
ionizing radiation-induced DNA damage (Yong et. al., 2009) and that curcumin may decrease
free-radicals as well (Akpolat et al., 2008). A good antioxidant supplement formula includes a
combination of vitamins C and E, lipoic acid, and CoQ10 since they work in synergy and greatly
enhance the power of one another to eliminate free-radicals (Packer & Colman, 1999).
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11
Get enough sleep since the positive effects of melatonin against oxidative stress caused by
ionizing radiation have been proven (Karbownik & Reiter, 2000). Melatonin is produced in the
brain while we sleep as well as in the gut.
Ensure that the body’s core systems, including immune, digestion, and detoxification systems are
functioning as they should so that the body can fight and eliminate toxins. More information
about this on my website at www.resettinghealth.com
Conclusion
In sum, crewmembers working trans-polar flights around 1000 hours per year are exposed to about 7
mSv from galactic radiation alone, an amount that exceeds the average amount other radiation workers
are exposed to and seven times the annual amount recommended to the general public. In the event of
solar storms, which are expected to peak this year, exposure to passengers and crews may increase by a
factor of 10 or 20 per flight. There is also the possibility of ionizing radiation from thunderstorms,
security scanners, and radioactive cargo. This is all in addition to the natural annual background
radiation of around 3 mSv per year and medical imaging radiation that averages about 3 mSv, or more
for crewmembers and passengers that have had CT scans. As if that is not enough, many crewmembers
have to fly even more due to lowered wages and increased hours. Recently it has been confirmed that
there is no safe level of ionizing radiation and that even low levels can cause cancer as well as other
adverse health effects. New studies of low dose radiation over longer periods show a significant
correlation between radiation dose and all causes of mortality. And a multitude of studies show high
levels of the same cancers in crewmembers.
With all this, I have one question… With regards to flight crews and frequent fliers, what happened to
the two fundamental principles for limiting radiation, justification and ALARA (keeping levels of radiation
“as low as reasonably achievable”)? Hopefully things will change soon because I, for one, do not care to
be another statistic in a future study on the detrimental effects of ionizing radiation on crews.
www.resettinghealth.com
12
References
Akpolat, M., Kanter, M., & Cem Uzal, M. (2009, June). Protective effects of curcumin against gamma radiationinduced ileal mucosal damage. Arch Toxicol, 83(6):609-617.
Association of Flight Attendants-CWA (2010, April). Cosmic and solar radiation: Facts for flight attendants.
Department of Air, Safety, Health, and Security. Retrieved from
http://ashsd.afacwa.org/docs/radbroch1.pdf
Badrinath, P., & Ramaiah, S. (1999, Jan. 9)). Risk of breast cancer among female airline cabin attendants, BMJ,
318(7176):125.
Band, P.R., Nhu, D.L., Fang, R., Deschamps, M., Coldman, A.J., Gallagher, R.P., & Moody, J.
(1996). Cohort study of Air Canada pilots: Mortality, cancer incidence, and leukemia risk. American Journal
of Epidemiology 143(2):137-143. Retrieved from http://aje.oxfordjournals.org on July 7, 2013.
Barish, R.J. (2009). (2nd ed.) The invisible passenger: Radiation risks for people who fly.
Advanced Medical Publishing, Inc. Madison, WI.
Barish, R.J. (2001, June 5). Airlines need to warn fliers on radiation. New York Times. Retrieved from
http://www.nytimes.com/2001/06/05/opinion/05iht-edbarish_ed2_.html.
Barnes, E.C. (1999). Ionizing radiation. p.101. US Department of Health and Human Services, ATSDR. CDC.
Retrieved from http://www.atsdr.cdc.gov/toxprofiles/tp149-c3.pdf
Beck, P., Dyer, C., Fuller, N., Hands, A., Latocha, M., Rollet, S., & Spurny, F. (2009, Oct.). Overview of on-board
measurements during solar storm periods. Radiat. Prot. Dosimetry, 136(4):297-303. doi:
10.1093/rpd/ncp208.
Blue, B. (2000, Aug. 22). Radiation exposure aloft – Are you being nuked? Avweb. Retrieved from
http://www.avweb.com/news/aeromed/181873-1.html
Buja, A., Mastrangelo, G., Perissinotto, E., Grigoletto, F., Frigo, A.C., Rausa, G., … Dominici, F. (2006, Jan.-Feb.).
cancer incidence among female flight attendants: a meta-analysis of published data. J. Womens Health
(Larchmt), 1591):98-105
Bushberg, J.T. (2009). Radiation exposure and contamination. The Merck Manual for Health Care Professional.
Retrieved from
http://www.merckmanuals.com/professional/injuries_poisoning/radiation_exposure_and_contamination
/radiation_exposure_and_contamination.html#v1113286
Butler, K.M., & Cool, D. (2010, 25 March). Answer to question #8900 submitted to “Ask the experts”. Health
Physics Society, Retrieved from http://hps.org/publicinformation/ate/q8900.html
CAA, Civil Aviation Authority. (2013). Aircrew exposure to cosmic radiation. Guidance material for the protection
of aircrew from the effects of cosmic radiation. Retrieved from
http://www.caa.co.uk/default.aspx?catid=49&pageid=7094
www.resettinghealth.com
13
Cardis, E., Vrijheid, M., Blettner, M., Gilbert, E., Hakama, M., Hill, C., … Veress, K. (2007, April). The 15-Country
collaborative study of cancer risk among radiation workers in the nuclear industry: estimates of radiationrelated cancer risks. Radiat. Res., 167(4):396-416. Retrieved from
http://www.ncbi.nlm.nih.gov/pubmed/17388693
Chabot, G. (2012, Jan. 25). Answer to question #10031 submitted to “Ask the experts”. Health Physics Society.
Retrieved from http://www.hps.org/publicinformation/ate/q10031.html
Chandler, D.L. (2011, March 28). Explained: Rad, rem, sievert, becquerels. A guide to terminology about radiation
exposure. MIT News Office. Retrieved from http://web.mit.edu/newsoffice/2011/explained-radioactivity0328.html
Chang, W.P., Hwang J.S., Hung M.C., Hu T.H., Lee S.D.,& Hwang B.F. (1999, Oct.). Chronic low-dose gammaradiation exposure and the alteration of the distribution of lymphocyte subpopulations in residents of
radioactive buildings. Int J Radiat Biol., 75(10): 1231-9.
Copeland, K., Sauer, H.H., Duke, F.E., & Friedberg, W. (2008). Cosmic radiation exposure of aircraft occupants on
simulated high-latitude flights during solar proton events from 1 January 1986 through 1 January 2008.
Advances in Space Research, 42(6):1008-1029. doi: 10.1016/j.asr.2008.03.001
Crampton, T. (2001, May 24). Flying on top of the world: A radiation risk. The New York Times. Retrieved from
http://www.nytimes.com/2001/05/24/news/24iht-radiate_ed3__0.html
Crampton, T. (2001, May 24). Fliers can calculate their levels of exposure. The New York Times. Retrieved from
http://www.nytimes.com/2001/05/24/news/24iht-risk_ed3_.html
Drucker, J. (2002, March 29). Concerns mount over exposure to radiation on airline flights. The Wall Street
Journal. Retrieved from http://online.wsj.com/article/0,,SB1017358222771363680,00.html
European Commission (2000). Referral guidelines for imaging. Radiation protection report 118. p.19. Retrieved
from http://ec.europa.eu/energy/nuclear/radioprotection/publication/doc/118_en.pdf
European Commission (2011, Nov. 14). Aviation security: Commission adopts new rules on the use of security
scanners at European airports. [Press Release]. Reference: 1P/11/1343. Retrieved from
http://europa.eu/rapid/press-release_IP-11-1343_en.htm
FAA, Federal Aviation Administration. (2006, July 6). Advisory Circular No. 120-61A. In-flight radiation exposure.
Oklahoma City, OK. Federal Aviation Administration, Flight Standards Service.
FAA, Federal Aviation Administration. (2012). Occupational safety and health standards for aircraft cabin
crewmembers. [pdf document][draft]. Retrieved from
http://www.faa.gov/about/initiatives/ashp/media/Draft_Policy_Occupational_Safety_and_Health_Standa
rds.pdf
FAA, Federal Aviation Administration. (n.d.). Secton II, 2.14, Exposure to radioactive materials. Retrieved 7/4/2013
from www.faa.gov/other_visit/aviation_industry/designees_delegations/... · DOC file
www.resettinghealth.com
14
FDA, Food and Drug Administration (2002). Radiation emitting products. Retrieved from
http://www.fda.gov/radiationemittingproducts/radiationemittingproducts
andprocedures/medicalimaging/medicatxrays/ucm115329.htm
FDA, Food and Drug Administration (2009). Reducing radiation from medical x-rays. Retrieved from
http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm095505.htm
Fink, C.A., & Bates, M.N. (2005, Nov.). Melanoma and ionizing radiation: is there a causal relationship? Radiat.
Res., 164(5):701-10.
Fisher, G., & Jones, B. (2007, March). Integrating space weather observations & forecasts into aviation operations.
Report of a policy workshop by American Meteorological Society (AMS) & SolarMetrics.
Florida Institute of Technology. (2013, April 10). Florida tech professors present dark side of dark lightning.
Retrieved from http://www.caa.co.uk/default.aspx?catid=49&pageid=7094
Fox, K. (2011, Aug. 9). Solar flares; What does it take to be X-class? NASA Goddard Space Flight Center. Retrieved
from http://www.nasa.gov/mission_pages/sunearth/news/X-class-flares.html
Fox, K. (2012, March 8). Storms from the sun. NASA Goddard Space Flight Center. Retrieved from
http://www.nasa.gov/mission_pages/sunearth/news/storms-on-sun.html
Fox, K. (2013, May 14). Three X-class flares in 24 hours. Third update. NASA Goddard Space Flight Center.
Retrieved from
http://www.nasa.gov/mission_pages/sunearth/news/News051213-flare.html
Francois, M.A., Milliat, F., Guipaud, O., & Benderitter, M. (2013). Inflammation and immunity in radiation damage
to the gut. BioMed Research International, Article ID 123241. Retrieved from
http://dx.doi.org/10.1155/2013/123241
Friedberg, W., & Copeland, K. (2003). What aircrews should know about their occupational exposure to ionizing
radiation. FAA Civil Aerospace Medical Institute. Retrieved from
http://www.faa.gov/data_research/research/med_humanfacs/oamtechreports/2000s/media/0316.pdf
Friedberg, W., & Copeland, K. (2011, May). Ionizing radiation in earth’s atmosphere and in space near earth. FAA
Civil Aerospace Medical Institute. DOT/FAA/AM-11/9. Retrieved from
http://www.faa.gov/data_research/research/med_humanfacs/oamtechreports/2010s/media/201109.pdf
Goldhagen, P. (1998). Overview of aircraft radiation exposure and recent ER-2 measurements. U.S. Department of
Energy. Program of the 1998 annual meeting. Retrieved from
http://www.ncrponline.org/Publications/Annual_Mtg_Proc/1998Program.html
Grajewski, B., Waters, M.A., Yong, L.C., Tseng, C., Zivkovich, Z. (2011, June). Airline pilot cosmic radiation and
circadian disruption exposure assessment from logbooks and company records. Ann Occup Hyg., 55(5):
465–475.
Published online 2011 May 24. doi: 10.1093/annhyg/mer024
Gundestrup, M., & Storm, H.H. (1999, Dec. 11). Radiation induced acute myeloid leukeamias and other cancers in
commercial jet cockpit crew: A population based cohort study. Lancet 354:2029-2031
www.resettinghealth.com
15
Hammer, G.P., Blettner, M., & Zeeb, H. (2009, Oct.). Epidemiological studies of cancer in aircrew. Radiat. Prot.
Dosimetry, 136(4):232-9. doi: 10.1093/rpd/ncp125.
HPS, Health Physics Society. (2011). Radiation exposure during commercial airline flights. HPS Website. Retrieved
from http://www.hps.org/publicinformation/ate/faqs/commercialflights.html
ICRP (1991) (1990). Recommendations of the International Commission on Radiological Protection. ICRP
Publication 60, vol 21(1-3)
ICRP, International Commission on Radiological Protection (2011, Jan. 20). Early and late effects of radiation in
normal tissues and organs: threshold doses for tissue reactions and other non-cancer effects of radiation
in a radiation protection context. Annals of the ICRP. Ref 4844-6029-7736. Retrieved from
http://www.icrp.org/docs/TissueReactionsReportDraftforConsultation.pdf
Irvine D, Davies DM. British Airways flightdeck mortality study, 1950-1992. (1999). Aviation Space and
Environmental Medicine 70:548-55
Jacob, P., Ruhm, W., Walsh, L., Biettner, M., Hammer, G., & Zeeb, H. (2009, June 30). Is cancer risk of radiation
workers larger than expected? Occup Environ Med., 66(12): 789-796. doi:10.1136/oem.2008.043265
Jacob, S., Michel, M., Brezin, A.P., Laurier, D., & Bernier, M.O. (2011). Ionizing radiation as a risk factor for
cataract: what about low-dose effects? J clinic Experiment Ophthalmol, S:1.
http://dx.doi.org/10.4172/2155-9570.S1-00
Johnson, J.C. & Thaul, S. (1997). An evaluation of radiation exposure guidance for military operations. National
Academy of Sciences. ISBN 0-309-05895-3.
Karbownik, M. & Reiter, R.J. (2000, Oct.). Antioxidative effects of melatonin in protection against cellular damage
caused by ionizing radiation. Exp Biol Med (Maywood), 225(1):9-22.
Lynch, P. (2009, Dec. 15). Solar storms and radiation exposure on commercial flights. NASA Langley Research
Center. Retrieved from http://www.nasa.gov/topics/aeronautics/features/airline-radiation.html
Macnaughton. (2001, Dec. 24). Review article: new insights into the pathogenesis of radiation-induced intestinal
dysfunction. Alimentary Pharmacology & therapeutics, 14(5):523-528. doi: DOI: 10.1046/j.13652036.2000.00745.x
Malik, T. (2013, May 13). Solar flare, strongest of 2013, blamed for hour-long radio blackout. Huffington Post.
Retrieved from http://www.huffingtonpost.com/2013/05/13/solar-flare-strongest-2013-radioblackout_n_3265358.html
Meehan, J., & Kunches, J. (2012). Workshop addresses aviation community. Space Weather,10, S08011.
doi:10.1029/2012SW000828.
Mertens, C.J., Kress, B.T., Wiltberger, M., Blattnig, S.R., Slaba, T.S., Solomon, S.C., & Engle, M. (n.d.). Aircraft
radiation exposure during a high-energy solar energetic particle event in October 2003. Space Weather,
pp1-9. Retrieved from http://sol.spacenvironment.net/~nairas/docs/NAIRAS_Hallow03_SEPdose_v5.pdf
www.resettinghealth.com
16
Mertens, C.J., Wilson, J.W., Blattnig, S.R., Kress, B.T., Norbury, J.W., Wiltberger, M., … Murry, J.J. (2008, Jan. 11).
Progress on NASA Nairas model development. [slides]. NASA Langley Research Center. Retrieved from
http://www.gwu.edu/~spi/assets/docs/Chris_Mertens-NASA.pdf
Mertens, C.J., Kress, B.T., Wiltberger, M., Tobiska, W.K., Grajewski, B., & Xu, X. (2012). Atmospheric ionizing
radiation from galactic and solar cosmic rays. Current topics in ionizing radiation research. NASA Langley
Research Center. Radiation Research, Dr. Mitsuru Nenoi (Ed.), ISBN:
978-953-51-0196-3, InTech, Available from: http://www.intechopen.com/books/current-topics-inionizing-radiation-research/atmospheric-ionizing-radiation-from-galactic-and-solar-cosmic-rays
Monti, P., Wysocki, J., Van Dermeeren, A., & Griffiths, N.M. (2005). The contribution of radiation-induced injury to
the gastrointestinal tract in the development of multi-organ dysfunction syndrome or failure. The British
Institute of Radiology, 27. DOI: 10.1259/bjr/53186341.
Mosher, D. (2011, June 8). Solar flares sparks biggest eruption ever seen on sun. National Geographic News.
Retrieved from http://news.nationalgeographic.com/news/2011/06/110608-solar-flare-sun-sciencespace/
National Academies. (2005). Low levels of ionizing radiation may cause harm. Retrieved
http://www8.nationalacademies.org/onpinews/newsitem.aspx?recordid=11340
NAS, National Academy of Sciences (2005). BEIR VII: Health Risks from Exposure to Low Levels of Ionizing
Radiation. National Academies Press: Washington DC. Available from http://www.nap.edu/catalog
NASA, National Aeronautics and Space Administration (2013, May 13). Major solar flare erupts from the sun,
strongest of 2013. Retrieved from http://www.infowars.com/major-solar-flare-erupts-from-the-sunstrongest-of-2013/
NCRP, National Council on Radiation Protection and Measurements (2011). Medical exposures to ionizing
radiation: Important developments since NCRP report no. 160 and other recent NCRP activities. Retrieved
from http://www.ncrponline.org/PDFs/2011/Idaho_11-7-11_DAS.pdf
NCRP, National Council on Radiation Protection and Measurements (2004, Dec.) Recent applications of the NCRP
public dose limit recommendation for ionizing radiation. NCRP Statement No. 10. Retrieved from
http://www.ncrponline.org/Publications/Statements/Statement_10.pdf
NCRP, National Council on Radiation Protection and Measurements (2012). NCRP and International consistency in
radiation protection standards. Health Physics Society 57th Annual Meeting. Sacramento, CA. Retrieved
from http://www.ncrponline.org/PDFs/2012/Boice_%20HPS_7-23-2012.pdf
NCRP, National Council on Radiation Protection and Measurements (2012). NCRP Facts file in About NCRP. NCRP
Online. Retrieved from http://www.ncrponline.org/AboutNCRP/About_NCRP.html
Nejdfors P, Ekelund M, Westrom BR, Willen R, Jeppsson B. (2000). Intestinal permeability is increased after
radiation therapy. Dis Colon Rectum;43:1582–8.
NIRS, Nuclear Information and Resource Service (2005, June 30). All levels of radiation confirmed to cause cancer.
Retrieved from http://www.nirs.org/press/06-30-2005/1
www.resettinghealth.com
17
NOAA, National Oceanic and Atmospheric Administration (2005). The NOAA space weather scales. Retrieved from
http://www.swpc.noaa.gov/NOAAscales/
NRC, United States Nuclear Regulatory Commission. (2011, Oct.). Fact sheet on biological effects of radiation.
Retrieved from http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/bio-effects-radiation.html
NRC, United States Nuclear Regulatory Commission. (2013). Information for radiation workers. Retrieved from
http://www.nrc.gov/about-nrc/radiation/health-effects/info.html
Ott, C., & Huber, S. (2006, Jan. 25). [The clinical significance of cosmic radiation in aviation]. Praxis (Bern 1994);
95(4): 99-106. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/16485604
Packer, L., & Colman, C. (1999). The antioxidant miracle. John Wiley & Sons, Inc. Canada.
Palmer, R. (2013, June 11). Solar activity peaks in 2013: More solar flares expected later this year. International
Business Times. Retrieved from http://www.ibtimes.com/solar-activity-cycle-peaks-2013-more-solarflares-expected-later-year-1302041#
Picano, E., Vano, E., Semelka, R., & Regulla, D. (2007, Oct. 31). The American College of Radiology white paper on
radiation dose in medicine: deep impact on the practice of cardiovascular imaging. Cardiovascular
Ultrasound, 5:37. doi: 10.1186/1476-7120-5-37.
Pukkala E, Aspholm, R., Auvinen A., Eliasch, H., Gundestrup, M., Haldorsen, T., … Tveten, U. (2002, September 14).
Incidence of cancer among Nordic airline pilots over five decades: occupational cohort study. BMJ,
325(7364):567.
Rafnsson, V., Hrafnkelsson, J., & Tulinius, H. (2000, March). Incidence of cancer among commercial airline pilots.
Occup Environ Med., 57(3);175-179. doi: 10.1136/oem.57.3.175
Rafnsson, V., Tulinius, H., Jonasson, J.G., & Hrafnkelsson, J. (2001, Feb.). Risk of breast cancer in female flight
attendants” a population-based study (Iceland). Cancer Causes Control,
12(2):95-101.
Reynolds P, Cone J, Layefsky M, Goldberg D, Hurley S. (2002, May). Cancer incidence in California flight
attendants. Cancer Causes control, 13(4):317-24.
Roquin, A., & Nair, P. (2007). Radiation during cardiovascular imaging. Br J cardiol., 14(5):289-292.
Salhab, M., & Mokbel, K. (2006). Breast cancer risk in flight attendants: an update. Int. J. Fertil> Women’s
med.,51(5):205-7.
SCENIHR (2012). What are the current guidelines for radiation protection? In Health effects of security scanners
(based on X-ray technology). Retrieved from http://ec.europa.eu/health/opinions/securityscanners/en/1-3/2-radiation-protection.htm
Schauer, D.A., & Linton, O.W. (2009, Nov.). National council on radiation protection and measurements report
shows substantial medical exposure increase. Radiology, 253, 293-296. doi: 10.1148/radiol.2532090494.
www.resettinghealth.com
18
Science Daily (2005, September 1). Flying and radiation risk. Physicist calls for airline industry to educate workers
about radiation. Retrieved from http://www.sciencedaily.com/videos/2005/0907flying_and_radiation_risk.htm
Sherbini, S. (2000). Policy, guidelines, and regulations – ALARA. Health Physics Society. Retrieved from
http://www.hps.org/publicinformation/ate/q435.html
Shimoi ,K., Masuda, S., Shen, B., Furugori, M., & Kinae, N. (1996, Feb. 19). Radioprotective effects of antioxidant
plant flavonoids in mice. Mutat Res., 350(1):153-61.
Shulman, M. (2008, May 30). Facing a CT scan? Think about radiation. US News and World Report. Retrieved from
http://health.usnews.com/health-news/managing-your-healthcare/cancer/articles/2008/05/30/facing-act-scan-think-about-radiation
Sigurdson, A.J., & Ron, E. (2004). Cosmic radiation exposure and cancer risk among flight crew. Cancer Invest.,
22(5):743-61. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/15581056
Sykes, A.J., Larsen, P.D., Griffiths, R.F., & Aldington, S. (2012, Oct.). A study of airline pilot morbidity. Aviat. Space
Environ. Med., 83(10):1001-5
Thiagarajah, J., Gourmelon, P., Griffiths, N.M., Lebrun, F., Naftalin, R.J,, & Pedley, K.C. (2000). Radiation-induced
cytochrome c release causes loss of colonic fluid absorption by damage to
crypts and pericryptal myofibroblasts. Gut, 47: 675–84.
Umar, S. (2010, Oct.). Intestinal stem cells. Curr Gastroenterol Rep., 12(5):340-348.
Volzke, H., Werner, A., Wallaschofski, H., Friedrich, N., Robinson, D.M., Kindler, S., Kraft, M., John, U., &
Hoffmann, W. (2005, Aug.). Occupational exposure to ionizing radiation is associated with autoimmune
thyroid disease. J Clin Endocrinol Metab. 90(8):4587-92.
Wrenn, E. (2012, July 9). Are we safe from the sun? Solar flares keep on getting stronger – with latest hotspot the
size of 15 earths strung together. Daily Mail. Retrieved from
http://www.dailymail.co.uk/sciencetech/article-2170985/The-suns-solar-flares-getting-stronger--latesthot-spot-size-15-Earths-strung-together.html
Yong,L.C., Petersen, M.R., Sigurdson, A.J., Sampson, L.A., & Ward, E.M. (2009, April 18-22). Antioxidant intake and
chromosome translocation frequency among airline pilots. Proceedings of the American Association for
Cancer Research (AACR) 100th Annual Meeting. Denver, Colorado. Abstract 73(50):18
www.resettinghealth.com
19