Please present and summarize as many scientific studies that you can
find that discuss the dangers of radiation absorbed during flying. 
And if there is anything that can be done to prevent it besides flying
less!

Also, if there is anything that you find that discusses the affects on
toddlers/children, I would appreciate you highlighting that.

I've done some searching on the internet already but what I'm looking
for is for someone to help summarize all the various studies and
findings out there.  Seems to be a somewhat controversial subject with
no conclusive findings.  What I basically know is that levels of
radiation depend on proximity of flight to the equator, hours in the
air, and altitude.  I also heard some people can purchase lead baby
carriers?!

My family does a bit of travelling to southern Africa from the States
- about 80-120 hours of flight time a year and I'm wondering if we
should cut down our trips because of the radiation issue.  I'm
particularly concerned about my 2 yr old son.

Thank you in advance!

Hi there,

This is something I have a personal interest in, so here's what I have
bookmarked previously, what I found from searching today, and my
thoughts.


Lead baby carriers
------------------
It was reported in the Herald Sun that supermodel Elle MacPherson

"...allegedly lined her baby's cot with lead to shield him from cosmic
rays on planes."

The article no longer exists online, and that was the only part of it
I saved.


Scandinavian Study
------------------
In terms of length of time and number of participants, this is the
biggest study on the topic:

"The closer you get to the sun, the greater is your exposure to the
cosmic radiation that it emits. Some people theorized that airline
pilots, who are regularly exposed to greater cosmic radiation, would
consequently have a greater incidence of cancer. A study of more than
10,000 male Scandinavian airline pilots, however, shows no greater
risk for this group compared to others The average monitoring period
in the study was 17 years. Although there was a slightly higher rate
of skin cancer among the pilots, there is the possibility that it
might be linked to recreational, as opposed to occupational, exposure
to the sun."
http://news.bmn.com/jscan/medicine?uid=19693

"Results: 466 cases of cancer were diagnosed compared with 456
expected. The only significantly increased standardised incidence
ratios were for skin cancer: melanoma 2.3 (95% confidence interval 1.7
to 3.0), non-melanoma 2.1 (1.7 to 2.8), basal cell carcinoma 2.5 (1.9
to 3.2). The relative risk of skin cancers increased with the
estimated radiation dose. The relative risk of prostate cancer
increased with increasing number of flight hours in long distance
aircraft."
http://bmj.com/cgi/content/full/325/7364/567


FAA Report
----------
"...the FAA estimates that for a crewmember who flies 900 hours a year
for 30 years on flights between the US and Europe, the excess risk of
radiation-induced fatal cancer can be as high as 1%. That means that
the risk of dying from cancer (in general) might go up from 20% to
almost 21%. Another way to look at it is that of every 100 such
crewmembers, one can expect to die of radiation-induced cancer."
http://www.afanet.org/cosmicradiation.asp

The FAA report in full:
http://ntl.bts.gov/DOCS/Ac12052.html


Other Studies
-------------
Assessing exposure to cosmic radiation during long-haul flights
www.irpa.net/irpa10/cdrom/00132.pdf 

Exposure to cosmic radiation in the plane
http://www.sievert-system.org/WebMasters/en/contenu_exposition.html

Health Canada's recommendation:

"Pregnant women who expect to fly more than 200 hours over the course
of their pregnancy should seek further information from the Radiation
Protection Bureau, Health Canada on the radiation risks for unborn
children."
http://www.hc-sc.gc.ca/hecs-sesc/rpb/cosmic.htm

Galactic radiation exposure during commercial flights: Is there a
risk?
http://www.cmaj.ca/cgi/content/full/168/9/1157


High dosage safer?
------------------
It has been suggested that, contrary to logic, it is the lower levels
of radiation that are the most dangerous. The reason being that it is
only when a lot of damage is done that our DNA repair systems kick in.

It is possible that the doses you receive during a fly are of little
harm, because it is at level that invokes your DNA repair system,
without overloading it. More here:
http://www.abc.net.au/science/news/stories/s820717.htm


In Perspective
--------------
Most radiation exposure comes from the earth, usually from radon gas.

"The effect of radiation on health must be discussed within the
context of the natural background. Background radiation consists of
cosmic rays from space and radiation present in the earth from when it
was formed. Cosmic radiation increases with altitude and so airline
pilots receive a high exposure from this source; the dose rate at
12,000 metres being about 150 times the sea level dose. The
terrestrial radiation comes from naturally occuring radiosiotopes of
potassium and rubidium and from decay products of uranium and thorium.
On average two thirds of the dose people receive comes from
terrestrial sources. Most of this dose comes from the gas, radon,
which is a decay product of uranium and thorium."
http://www.arpansa.gov.au/is_rad.htm

Source Of Exposure                                   Exposure 

Natural Radiation (Terrestrial and Airborne)         1.2 mSv per year
Natural Radiation (Cosmic radiation at sea level)    0.3 mSv per year
Total Natural Radiation                              1.5 mSv per year
Seven Hour Aeroplane Flight                          0.05 mSv 
Chest X-Ray                                          0.04 mSv 
Nuclear Fallout (From tests in 50's & 60's)          0.02 mSv per Year
Chernobyl (People living near Chernobyl)            10 mSv per year 
Cosmic Radiation Exposure of Domestic Airline Pilot  2 mSv per year 
http://www.arpansa.gov.au/is_rad.htm

The UNSCEAR report from 2000 puts the average annual background
exposure at 2.4 mSv.
http://www.un.org/ha/chernobyl/unsceare.htm

The only possible bias I can think of for big pilot study is that
Scandinavians already have low cancer rates, which might be related to
the high amount of terrestial background radiation they are exposed
to. Finnish and Swedish households have more than double those in the
USA.
http://www.who.int/entity/ionizing_radiation/
env/en/Radon_Info_sheet.pdf

In other words, the pilots are not experiencing as much total increase
in radiation as those in some other countries would. Also, higher
latitudes receive more cosmic radiation - at the poles it is twice as
strong as the equator.

So, the Scandinavian study could be flawed due to the pilots having a
higher than normal tolerance to radiation, relative to those in
countries like the USA. But that's just my thought.


Children
--------
Ordinarily children are more at risk from the environment than adults,
because pound-for-pound they eat, drink and breathe more than we do.
These factors have no bearing on cosmic radiation. The only pertinent
factor I could find is quoted from WHO:
"Children have more time to develop diseases with long latency, more
years of life to be lost and more suffering to be endured as a result
of impaired health."
http://www.who.int/inf-fs/en/fact261.html


What should you do?
-------------------
In the future you will be able to buy regular clothing that protects
you from radiation...
http://2012.antville.org/stories/206191/

...but until then all you can do is try place a value to your family
on your trips to Africa, and compare the beneifts to the minor
radiation risks. When we play sports we risk crippling injury, when we
drive we risk being in a major crash, smoking tobacco has its obvious
dangers, some enjoyable foods are bad for us... We are constantly
making trade-offs between lifestyle and health.

100 hours of flying in a year gives you approximately 50% more total
radiation exposure than those who never fly. The biggest study says
you have nothing to fear. The FAA suggest that your increased rate of
getting cancer is 0.005% for each year that you fly for 90 hours.

The only solution given to airline crew is "fly less". I could not
find any product made available to airline crew to reduce their
exposure, nor for the general public.

"There is no practical way to shield oneself from galactic radiation
on flights."
http://www.cmaj.ca/cgi/content/full/168/9/1157

Far more important for preventing cancer are things like protecting
yourself from direct sunlight, diet and exercise.

You should also check the radon levels of your home:

"Radon is found all over the United States. Scientists estimate that
nearly one out of every 15 homes in this country has radon levels
higher than four picocuries per liter, the level above which EPA
recommends that homeowners take corrective action. Picocuries per
liter is how radon in the air is measured. Testing your home is the
only way to know if you and your family are at risk from radon.

Testing for radon is easy and only takes a few minutes of your time.
There are many kinds of low-cost, "do-it-yourself," EPA-approved or
state-certified radon test kits available through the mail or from
retail outlets. You can also hire a professional to do the testing.
EPA recommends choosing a state-certified and/or EPA-listed
measurement company."
http://www.ehso.com/nuclear-radiation.htm


Best wishes,
robertskelton-ga

Thanks so much for the research.  This was exactly what I was looking
for!  Very thorough indeed.