Calli Arcale said:

If you want another twist to this, some folks are now suggesting that the South Atlantic Anomaly could have been involved in the recent tragic Air France crash, when all evidence currently points strongly towards iced-over airspeed indicators (a known issue with A330s that now has some pilots refusing to fly them). It’s highly unlikely, but I imagine the radiation fearmongers will pick up on that. The SAA does tend to have higher rates of cosmic rays due to decreased field strength in the Earth’s magnetic field, though not *that* much, at the altitudes at which airliners fly.

It had actually occurred to me, shortly after the crash, that the location put it flying through the heart of the South Atlantic Anomaly. I really doubt this had anything to do with it, and the data thus far seems to indicate that is unrelated. However, the South Atlantic Anomaly does not only have the effect of producing increased exposure to cosmic radiation at very high altitudes. The area is well known for experiencing unusual geomagnetic activity, of course the classic one is having compasses reverse, but it also has field fluctuation and very unusual radio propagation effects.

There’s of course nothing that mysterious about this. The area is known to be an anomaly in the earth’s magnetic field and it is therefore prone to greater ionospheric activity and magnetic variation. The same thing happens at the poles, especially during a geomagnetic storm or a solar flare or something.

Even on an aircraft that is as “wired” as the A330, it would take more than some local fluctuation to really mess with the systems enough to bring it down. Also, at the time of the crash there was nothing unusual going on in that respect. The data from SOHO, various space weather observatories and world propigation reports have all indicated nominally low activity and it would be pretty unlikely to get a major geomagnetic event now anyway, given that we’re still in a fairly low activity period of the solar cycle.

Anonymous: there are instruments that directly tell us what the dose is, notably an ion chamber (real time) or dosimetry such as film badges. A Geiger counter is worthless for determining dose unless it has been calibrated to the energies of the radiation which it is seeing.

1074Jacob: to add one more fact to your list of worries, you should know that there is an average of 2 pCi of Uranium per GRAM of soil in all soil, some of which gets taken up into the plants we eat. All the soil you walk on is teeming with radiation! Absolutely teeming, I say! Given your propensity to take extremely small risk and apply it to your utopian idealism, you should extrapolate this fact and urge a ban on all farming and food ingestion. Please be the first to adopt this ban.

        1974Jacob said:

This is just one more reason to limit flying.
We already fly too much and it is one of the luxuries that is killing the enviornment.
Flying is going to be only for when it is completely necessary and that is almost never.
Most flying is for people taking holiday for their own pleasure at the planet’s expense.
Some people take a holiday by plane every year and this is inexcusable and criminal to the world.
Radiation adds one more reason to curtail this.

Well then we better limit some other things that expose people to radiation too:
Better limit living in Colorado.
Better limit granite coutertops.
Better limit heating & cooking with natural gas.
Better limit eating bananas.
Better limit using electricity generated by radiation spewing natural gas and coal plants…
…quick, 1074Jacob, turn your computer off right now!

As for the exposure limits, what is a safe dose and how does it compare with the worst case of what airliner crews get?

        Anonymous said:

they do get exposed to more than those who work at nuclear facilities, so unless you can justify not having radiation monitoring equipment at nuclear or coal power plants, or in grand central station…

The reason dosimeters are worn at nuclear facilities is not just to measure the low exposure levels a worker normally encounters. Stuff like spent fuel is pretty radioactive and if it were grossly misshandled or if somehow someone got too close to something they shouldn’t like a discharge of radioactive gas then they could get a really high dose. This almost never happens, but it’s a precaution to catch it if some kind of situation happens that causes it.

When it comes to safety I doubt it really matters that much to count the milirems exactly for each and every worker, under normal circumstances that is. If nothing goes wrong and nobody makes a mistake or does something they shouldn’t, then it would always be well bellow the levelsof anything dangerous.