Did you know that...

When traveling by plane you are exposed to cosmic radiation and the influencing factors are:
- altitude - exposure increases with altitude
- latitude - exposure varies according to latitude
- duration - exposure depends on the duration of the flight
It is said that a plane trip from New York to London or any other flight of similar duration and latitude and altitude exposes passengers to a quantity of radiation about as high as a chest X-ray!.
So the flights over the polar regions take double radiations than the ones over Equator.
The level of radiations doubles every 2000 m altitude!
If you want to calculate how much radiation you get for your flights you can access the public part of S.I.E.V.E.R.T - acronym in France for the Computerized System for Assessing the Exposure to Cosmic Radiation during Air Transportation:
http://www.sievert-system.org/WebMasters/en/evaluation.html