A Delta Air Lines flight that diverted to Tulsa on Saturday after a dozen passengers fell ill prompted concerns about carbon monoxide on the plane, but it's still unclear where the gas may have come from.
According to Delta spokesman Morgan Durrant, the plane was "thoroughly tested" and no traces of carbon monoxide were detected, nor was a source of the gas found.
Flight 1817 on an MD-90 jet departed from Atlanta on Saturday and was bound for Denver, but after several passengers showed signs of sickness, the crew decided to land at Tulsa International Airport.
Tulsa Fire Department spokesman Stan May said the exposures were "very low level and their symptoms were they were drowsy, and a couple of them felt nauseous."
Paramedics tested the passengers using a pulse oximeter "to determine how much oxygen and how much carbon monoxide is in your system," but did not conduct a blood test, May said Monday.
"It's a non-invasive test. We didn't actually draw blood," May said. Pulse oximeters are "not near as accurate as a blood test, but there was no need for a blood test because the levels were so low, and they were already coming down. So once we got them to the fresh air, it was no longer an issue," he said.
May speculated an item like an aerosol can in luggage or in a carry-on may have caused the issue.
"It apparently wasn't caused by the airplane itself," May said. "Whatever it was had stopped off-gassing by the time we were called in to put the meters to it, because we didn't find it in the air," but just detected it in the passengers.
The Transportation Security Administration prohibits large cans of aerosol and other flammable items in carry-ons and checked bags. Small aerosol containers of less than 3.4 oz for personal care or toiletries are allowed.
May said when the plane landed in Tulsa, "there was no danger to the crew or any of the passengers. But they did the appropriate thing. They had an issue, and they found a place to put the plane down to check it out, and they erred on the side of the safety of the passengers."