The airline industry has long denied the existence of aerotoxic syndrome, despite consistent reports of pilots, flight attendants and passengers being hospitalised for falling ill or experiencing ongoing symptoms related to these events. Some have even died.
Aerotoxic syndrome can occur when the cabin air, which is "bled" in from the engines to pressurise it, is compromised. This bleed air can be contaminated with heated engine oil fumes that contain hazardous chemicals, which crews and passengers breathe and may also absorb through the skin.
According to a 2014 report from the Australian Transport Safety Bureau, passengers and crew on Australian aircraft were exposed to toxic fumes more than 1000 times over the five years leading up to the report.
The investigation found that in several cases crew performed forced landings because of the fumes - but routinely passengers were never warned of the dangers.
Former Australian pilot Susan Michaelis, now head of research at the Global Cabin Air Quality Executive, claimed she collapsed from aerotoxic syndrome after repeated exposure to fumes from heated jet oil in the cockpit of a BAe146 aircraft. She is now one of the country's leading advocates in highlighting the danger of toxic fumes bleeding into the cabin.
Ms Michaelis believes aerotoxic syndrome has left her with permanent neurological problems.
"Sitting in an unhealthy environment and being exposed to chemicals every day made me sick," she told the Daily Telegraph.
"There is a pattern of chronic ill-health ... and it needs to be looked at further. My research has found clusters of pilots with brain cancer in the UK. They were mostly flying short-haul journeys.
"The way the engines are designed means crew and passengers are exposed to hazardous fumes. These have both short-and long-term health impacts including cancer."
Ms Michaelis was diagnosed with breast cancer in 2013.
But Australia's Civil Aviation Safety Authority (CASA) isn't convinced.
In a 2009 report titled Contamination of Aircraft Cabin Air by Bleed Air, CASA said that recognising the potential for contamination of cabin air from bleed air is "important" but the evidence is still out.
"Despite the large amount of information available to the Panel, there remain many unanswered questions in seeking to understand the potential for exposures to engine oil in aircraft cabins and the acute and chronic effects on a person's health as the result of such exposures," the report stated.
"The information available about the association between specific contaminants and symptoms appeared more frequently conjectural rather than definitive."
