Several factors can explain why pilots acquire higher-than-average radiation. For starters, the farther you ascend into the air, the more you are exposed to the ultraviolet rays of the sun. One study measuring the amount of UV radiation in the pilot seat of an aircraft indicated that flying for under an hour at an altitude of 30,000 feet is the equivalent of a 20-minute tanning bed session regarding UVA radiation exposure. Furthermore, higher altitudes increase exposure to cosmic radiation, high-energy radiation typically filtered by the time it reaches Earth. When flying, the filtration of cosmic radiation is diminished.