For people with lung problems, the air quality found in commercial airliners can produce a drop in blood oxygen below recommended levels, Australian researchers report.

Previous reports have linked chronic obstructive pulmonary disease (COPD) such as emphysema with low blood oxygen levels while flying, but it was unclear if the same held true for interstitial lung disease - a large group of disorders that involve inflammation of the lower respiratory tract and breakdown of the structures that transfer oxygen to the bloodstream.

Dr. L. M. Seccombe and colleagues, from the Concord Repatriation General Hospital in Sydney, subjected 15 people with interstitial lung disease and 10 with COPD to a reduced-oxygen environment simulating the air in the cabin of a commercial aircraft during flight.

At sea level, all of the subjects had acceptable blood oxygenation.

Exposure to the simulated cabin atmosphere produced a significant drop in oxygen saturation in both groups of patients, according to the report in the medical journal Thorax.

The COPD patients had significantly lower oxygen levels than the people with interstitial lung disease patients, but the average levels in both groups were below recommended limits.

The team says that measuring blood oxygen levels at sea level probably should not be used to predict oxygen levels during air travel.

SOURCE: Thorax, November 2004.