clipped from www.worldnetdaily.com

Loranie said in today's passenger jets, half of the cabin air is recirculated from the cabin itself, with only a filtration system to clean it up.

"It's the other 50 percent of cabin air, however, that is the problem, because it comes from deep within the engines that are flying the plane. Bled off from the engine – and, therefore, known as 'bleed air' – before the fuel is injected and burnt, bleed air is piped back to the fuselage where it is cooled down and then pumped into the cabin," he said.

"Crucially and extraordinarily, bleed air is not filtered at all," he said. That leaves whatever chemicals and toxins it may have picked up in passing through the engine being pumped directly to pilots, flight crew members and passengers.

He said airline industry leaders keep the level of toxicity a closely guarded secret.