Argentine footballer Emiliano Sala and his pilot, both dead in January in the crash of their plane, were probably exposed to "potentially lethal" levels of carbon monoxide.

"Toxicological tests revealed that the passenger had a high saturation level of COHb [carboxyhemoglobin, which combines carbon monoxide and hemoglobin and inhibits the delivery of oxygen in the body]," said Wednesday, August 14 the British Air Accident Investigation Bureau (AAIB) in a special bulletin.

Potentially fatal

According to the tests, Sala had a carboxyhemoglobin saturation (COHb) level of 58%. "A COHb level of 50% or more in an otherwise healthy individual is generally considered potentially fatal," says the AAIB. "It is considered likely that the pilot would also have been exposed to carbon monoxide," the statement added.

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According to the AAIB, carbon monoxide poisoning poses a particular risk to the type of aircraft in which the two men traveled. "Piston-engine aircraft produce high concentrations of carbon monoxide that are sent out of the aircraft by the exhaust system," the investigators said. "Improper cabin sealing or leaks in exhaust gas heating and ventilation systems can allow carbon monoxide to enter the cabin" and into the cockpit.

Exposure to gases can damage the brain and the nervous system. Unconsciousness and heart attacks are possible with COHb levels above 50%. "It is clear from the symptoms that exposure to carbon monoxide (CO) can reduce or inhibit the ability of a pilot to fly an airplane based on the level of exposure," explains the AAIB.

Sala's family believes that a thorough examination of the wreckage of the aircraft is necessary to determine how the gas was able to seep into the cabin.

"The dangerously high levels of carbon monoxide found in Emiliano's body raise many questions for the family, and the causes of death will be determined during the investigation when the time comes," she said in a statement.

Emiliano Sala disappeared over the Channel on 21 January when he was aboard a single-engine Piper Malibu who was taking him from Nantes, a club he had just left, to his new club, Cardiff City at Wales. His body was found at the same time as the wreckage of the plane, two weeks later, 67 meters deep, near the town of Surtainville, in the English Channel. The pilot's body was not found.

With AFP and Reuters