According to the article, one main culprit, known to the airline mfgs, is the typical location of the air intakes means that a leaking seal can lead to toxic or

According to the article, one main culprit, known to the airline mfgs, is the typical location of the air intakes means that a leaking seal can lead to toxic organics spreading to the cabin. In fact, they cite the novel intake location on the 787 dream liners as avoiding this air quality issue. A first step to investigating how serious of an issue the air quality is during fume events would be to actually measure the air quality during fume events, which congress instructed/mandated the FAA do in 2003, per the article. But to paraphrase, the airlines told the FAA to take a hike, and they obeyed. If the mfg can repeatedly mislead the regulators and the airlines they are purportedly regulating can tell them to pound sand when they try to investigate, it means the regulators are failing. Yes it also means Boeing is in the wrong and the airlines, but it means the FAA has dropped the ball. I'm not sure what you're trying to say with the statement that gas flows along pressure gradients... temperature flows along temperature gradients... why does that standard behavior change anything in the analysis.