Basing this upon Walter's quoted sources.
Great posts Walter much appreciated
A one in 10,000 risk is hard to measure. Looking for linearity or non linearity below 10 millisieverts (level assumed to give a one in 10,000 risk of cancer spread across a lifetime) is fraught with practical difficulties - trying to measure numbers very close to zero, its not easy
With the assumption of linearity. 1 hour subsonic flying time calculates to a 1 in 2 million risk level.
The dose from a scan at 0.1 microsievert equates to to radiation received during 1.2 minutes flying.
For me that is negligible. But as always the risk is not zero - calculates through to a 1 in 100 million extra risk of cancer sometime in one's lifetime.
When the national lottery first appeared the odds of winning were in in 14,000,000
For mobile phones (microwave radiation) and power lines (magnetic fields) multiple studies have been inconclusive. That means too low to measure accurately - inconclusive unless you cherry pick the data.
All this concern about miniscule levels of risk.........
Yet airports continue to sell tobacco products and we continue to inhabit granite rich areas (radon gas).
Public Health England publishes the following table showing the risk of lung cancer for smokers, non smokers and ex smokers. The results vary with radon level in Becquerels. (The simple radiation unit, 1 Becquerel equals one radioactive decay per second).
Columns not well alligned I'm afraid
<!-- m --><a class="postlink" href="http://www.ukradon.org/information/risks">http://www.ukradon.org/information/risks</a><!-- m --> should be a working link.
Indoor radon level (Bq m-3) Non-smoker Ex-smoker gave up at age 30 Ex-smoker gave up at 50 Current Smoker
20 Less than 1 in 200 1 in 60 1 in 18 1 in 7
200 1 in 190 1 in 48 1 in 14 1 in 5
800 1 in 100 1 in 28 1 in 8 1 in 3
So for a smoker, who quit at age 50, the risk of lung cancer increases from
From 1 in 7 in a low radon environment (20 Bq)
to 1 in 3 in a high radon environment (800Bq)
<!-- m --><a class="postlink" href="http://www.ukradon.org/information/risks">http://www.ukradon.org/information/risks</a><!-- m --> should be a working link to Public Health England data
In summary
The 1 in 100,000,000 risk does not worry me. (one airport X ray scan)
A 1 in 14,000,000 chance tells me that, with more than 95 % certainty, I won't win the lottery this week - not unless I buy more than 700,000 tickets
Less than 1 in 200 risk (non smoker low radon area) is unfortunate but can't be reduced.
1 in 3 to 1 in 7 chance (depending upon radon level in home) of getting lung cancer for smokers who quit at 50 tells me that
Smoking is dangerous.
)
