Of course, contaminated air may not be the only culprit. Airplanes are full of Electromagnetic Radiation (EMR) sometimes referred to as "Electrosmog". Besides standard electrical operating equipment, most planes now offer free WiFi (a source of wireless radiation) to passengers. Exposure to toxic chemicals combined with exposure to Electromagnetic Fields - including WiFi - increases the toxic body burden.
Wireless radiation impairs the body's ability to protect itself from toxic chemicals by damaging the blood-brain barrier.
As noted in the 60 Minutes segment, some people are more affected by exposure to toxins than others. Of course, that still doesn't make it right that any of this is happening.
The Air Force study also looked at cockpit exposure, finding that "pilots have greater environmental exposure to ultraviolet and ionizing radiation ... (fighter pilots) have unique intra-cockpit exposures to non-ionizing radiation."
Retired Navy Cmdr. Thomas Hill was a career F-4 and F-14 pilot and squadron commanding officer with more than 3,600 flight hours and more than 960 aircraft carrier landings. Hill was 52 when he was diagnosed with a brain tumor. In December 2011, at age 60, he learned he also had esophageal cancer.