A coroner has warned toxic fumes in plane cabins pose a risk of health damage to aircrew and frequent fliers.
Sheriff Stanhope Payne, the senior coroner for Dorset, said those regularly exposed to such fumes faced "consequential damage to their health".
His comments were made in a Regulation 28 report, to prevent further deaths, following initial investigations into the death of a co-pilot.
Richard Westgate, 43, a co-pilot for British Airways, died in December 2012, believing he had been poisoned by repeated exposure to contaminated cabin air.
Mr Payne's report, sent to British Airways and the Civil Aviation Authority, raised five serious matters of concern about contaminated air and cabin air quality.
Frank Cannon, of Cannons Law Practice, acting on behalf of Mr Westgate's family, said industry had denied that toxic contamination was present 20 years ago.
Mr Cannon said the industry had stated that such contamination "won't do you any harm" after scientific tests established its presence in aircraft cabins.
After cases of harm emerged, the position became that the contamination was below minimum safety levels, Mr Cannon claimed.
"Minimum safety levels are a fallacy, with no known scientific basis," he said. " Real neurotoxic injury is caused by long-term low-level exposure.
"When a plane lands, the passengers get off, but the crew turn around and do the same thing all over again, day in day out.
"When monitoring or sample testing has taken place, the actual figures obtained are 'all over the place' with no consistency."
Mr Cannon said the figures demonstrated the number of variables such as maintenance, aircraft type, age and hours of engine life.
Sample testing never covers a whole flight, so it is unclear whether the figures obtained represent peaks or troughs of exposure, he added.
"Also very important is the issue of genetic variability between individuals," he said. " Some people have a DNA coding that means they lack the necessary enzymes to detoxify properly or at all.
"The rule emerges that if you are unable to detoxify between flights at a rate which is equal to or greater than the rate at which you are re-intoxicated by repetitive, successive and cumulative exposures, you will become extremely unwell."
It is common practice for airlines to use warm, compressed air taken directly from aircraft engines to pressurise the cabin.
This air is known as 'Bleed Air' and is known to become contaminated with engine oils and hydraulic fluids, the Global Cabin Air Quality Executive (GCAQE) said.
"Contaminated bleed air events have been recognised as occurring since the 1950s," it added. "Flight safety is being compromised by contaminated air events."
"Crew and passengers have been reporting short and long term health effects as a consequence of exposure of contaminated air."
The GCAQE said such events were not rare and were known to be under reported.
Captain Tristan Loraine BCAi, co-chairman of the GCAQE, said: "The only long term safe solution is for all aircraft to be built with the unique bleed free architecture currently flying onboard the Boeing 787.
"The Boeing 787 is the only commercial jet aircraft flying in which crews and passengers can fly knowing the air they breathe will be free of pyrolised and hazardous jet engine oil fumes."
Dr Susan Michaelis, head of research for GCAQE, added: "The industry was warned of the health risks of exposing crews and passengers to contaminated air as far back as 1954.
"It's only with the smoking ban in the late 1980s that the public finally realised the air they were inhaling could be contaminated.
"The serious Matters of Concern raised by the Senior Coroner for Dorset show that no crew member or passenger should ever be exposed to contaminated air, especially when the industry has an alternative solution flying on the Boeing 787."
A spokeswoman for British Airways said: "We will respond to the coroner in due course. It would be inappropriate to comment further while proceedings are continuing."