I get questions periodically from pilots and flight attendants about occupational radiation exposure. It has been known for some time that the exposures received by some flight personnel would require monitoring with dosimeters if they were working in the medical or nuclear industries.
The challenges to determining dose to a person in flight is complex in different ways than dosimetry on the surface of the planet. High altitude radiation includes particles and rays from distant star systems, from the sun, and from mysterious events out there that we are still struggling to understand. Some of the particles are “relativistic” in that they are traveling close to the speed of light. When they react with Earthʻs atmosphere, ionization occurs, and secondary forms of radiation are produced. Some of these reach the surface of our planet. If we could see these, or feel them, it would look or feel something like a light rain shower. During certain conditions we can visibly observe the interaction of cosmic rays with the upper atmosphere.
Earthʻs atmosphere shields us pretty well from the cosmic rays and particles that permeate outer space. A fraction makes it to the Earthʻs surface. The image on the left shows background radiation the runway at SFO International Airport in San Francisco. The level rises with altitude. The two iPhone screenshots below are from an App we are developing, linked to a 2 inch pancake GM sensor. The horizontal imagedocuments the entire flight between SF Bay Area and Palm Springs CA on the Android Wizkers App using the same sensor. More on the sensors and apps soon.
Here are a few links to information on radiation exposure in the airline industry.