The article has pretty poor reporting. I checked the first couple of examples they gave: https://abcnews.go.com/US/american-airlines-jet-suffers-fume-incident-

The article has pretty poor reporting. I checked the first couple of examples they gave: https://abcnews.go.com/US/american-airlines-jet-suffers-fume-incident-months-flight/story?id=44535862 https://abcnews.go.com/US/american-airlines-jet-suffers-fume... https://www.usatoday.com/story/travel/flights/2019/02/26/alaska-airlines-flight-diverted-due-odor-3-crew-members-hospitalized/2994132002/ https://www.usatoday.com/story/travel/flights/2019/02/26/ala... In both cases only the pilots/crew had issues, none of the passengers. In one case it was a "dirty sock" smell. If it was a bleed air problem, it would have affected passengers as well. A lot of research has been done, and there isn't actually any evidence showing that bleed air causes any health problems: https://en.wikipedia.org/wiki/Aerotoxic_syndrome#Research https://en.wikipedia.org/wiki/Aerotoxic_syndrome#Research Obviously there are some cases where the seals do break, and there is actual smoke in the cabin, but that is not what the majority of these cases are referring to.