I have thought the same thing for a while. When you're at the airport it smells like fuel. Everyone's talking about the radiation, but I'm wondering if pilots and stewardesses aren't exposed to much worse through the cabin air.
not surprisingly, airlines, manufacturers, and the FAA are all working together to suppress a thorough understanding.
the LA Times did a good investigatory piece at the end of last year: https://www.latimes.com/projects/toxic-chemicals-planes-covi...
When they start a jet engine, the fuel before it ignites would just blow out the exhaust. They catch it in a reservoir and pump it back into the engine to burn it off.
Well, that pump was glitching out, in some way they thought they could fix without a wrench. After about five minutes the fumes started getting sucked into the cabin, and every five minutes after they would tell us they were still working on it. What a shitshow.
The vast majority of the time the airplane is at cruising altitude, though. That air is as clean as you are going to get on planet earth.