How safe is the air inside airline cabins? In January 2020, a British Airways flight from Athens to London issued a mayday emergency call when the pilot flying the plane became incapacitated during a "fume event". The airline industry does not reveal how often fume events happen, but according to some estimates they occur every day. Pilots and cabin crew say that sudden fume events and long term low level exposure to toxic cabin air are making them seriously ill and in some cases causing premature deaths. The industry insists that serious leaks of toxic gas into cockpits and cabins are relatively very rare, given the number of flights each day. And that no causal link between toxic cabin air and health problems has yet been proven. But airlines face multiple court cases later this year. For Assignment, Mike Powell talks to a representative of the airline industry about fume events, lack of transparency and claims that the health of hundreds of pilots, cabin crew and frequent fliers is being put at risk. Presenter: Mike Powell Producer: Paul Waters