It’s summer and therefore, many people are flying on holiday. But what many people don’t know is that on an aeroplane, radiation exposure is higher. The earth is constantly being hit by cosmic rays and these rays strike the plane too. The rays are ionizing. And a too higher dose of this radiation can be harmful. So the question is, how dangerous is this ionizing radiation for those flying? The earth’s atmosphere filters out a large section of cosmic radiation. The atmosphere has magnetic fields and also directs the radiation from the poles. At the poles of the earth, therefore, the radiation is stronger than at the equator. Which is partly why we have auroras. The earth’s protective magnetic field is affected by solar activity and thus, the solar wind. The cosmic radiation on the ground is so much lower than higher up. And as said before you’ll find less cosmic radiation at the equator than at the earth’s poles. In order to calculate the radiation dose on the plane, you need to know four things: The exact route of flight, the altitude of the flight route, the duration of the flight and the prevailing solar activity. A computer program, then does the calculation work. So if you’re flying long distances, close to the poles, or at a particularly high altitude, the flight would then be subject to a greater average radiation exposure. For example: A flight from Frankfurt to New York and back would result in an additional radiation exposure… …of about 5% of the average annual radiation dose that we receive on the ground due to natural radiation. This is, however, not very much, and safe for adults and children. Yet, for pilots and the airline crew who fly much more often and all sorts of different routes… …their exposure is, of course, much larger, the airlines therefore keeps a track this and store this information. This will then ensure that their annual radiation exposure does not exceed the legal limit. All passengers can therefore, enjoy their flight, without worrying and look forward to their holidays.