Traveling by air is generally very safe. But this could be the airline industry’s best kept dangerous secret. It’s called aerotoxic syndrome and it comes from “bleed air” into the cabins and cockpits that contain toxins.
Bleed air is air that is forced into an airplane for breathing via engine turbine compression sections. The air is cooled and forced into the aircraft interior from inside the engine cowling or cover. Most cabin air is 60% bleed air and 40% recycled air. Pilots are subject to 100% bleed air, so they get hit the hardest from bleed air contaminants.
All jet liners and turboprop planes use the bleed air technique for cabin air with the exception of the new Boeing Dream Liner. Airlines refuse to acknowledge victims of aerotoxic syndrome. That would be catastrophic for their business.
But it’s a little more than coincidence that the Dream Liner was developed in the wake of more and more aerotoxic syndrome reports and exposure from airline pilots.