When it comes to catching an infection, planes no riskier than airports

A study carried out by the Australian Transport Safety Bureau has found there is no greater risk of catching an infection on a plane than in any other crowded and confined space.

Increasing numbers of people now travel by air for business and pleasure, but many people are concerned about whether, or to what extent, aircraft cabins represent an increased risk of transmission of infectious diseases.

There is also the worry of the global spread of diseases such as severe acute respiratory syndrome (SARS), TB and influenza which were reported to have been transmitted on board aircraft.

Though research has since revealed that most of the victims had been infected by sitting close to a sick passenger and exposed to droplets from sneezing or coughing rather than from contaminated re-circulated air, people still worry.

In order to assess the potential risk of disease transmission within an aircraft cabin, the Australian Transport Safety Bureau conducted a review of current research and literature.

The Bureau says the belief is that the air in planes is full of contaminants because it is continually recycled with limited input of fresh air, however the reality is that outside air enters an aircraft cabin at altitude and is at that point essentially sterile.

The pattern of the airflow pattern and frequent air exchanges also minimise the spread of infections and the ventilation system is designed to allow air entering the cabin at a given seat row to be exhausted at the same seat row, thereby restricting the amount of air flowing towards the front and back of the aircraft.

The bureau says the risk of transmission of infection on board an aircraft is probably no greater than, and perhaps less than, other environments where large numbers of people are gathered together.

The study suggests that the danger of infections spreading on planes is unlikely and the health of passengers is only at risk when circulation and filtration systems are not functioning properly.

There have been cases in the past of infectious diseases being transmitted in the air, but the report says they were probably due to crowding in a confined space, rather than cabin conditions.

The study also says there is more danger of infections spreading in airports than on planes, where passengers who are travelling to or from many destinations are gathered together.

But the bureau also found the increase in international travel has heightened the risk of infectious diseases spreading globally, and says the aviation industry should play a role in dealing with that risk.