Blood clots likely in long travel

A new study has found that the risk of developing a blood clot in the lung - called a pulmonary embolism - increased with the duration of air travel.Like deep vein thrombosis (DVT), pulmonary embolisms are blood clots that are believed to be associated with long-distance travel.

Frederic Lapostolle and colleagues, from Avicenne Hospital in Bobigny near Paris, studied all cases of pulmonary embolism needing care on arrival at France's busiest international airport, Charles de Gaulle, between November 1993 and December 2000.

There were 56 cases of confirmed pulmonary embolism out of more than 130 million passengers from 145 countries.Among people travelling less than 5000km, this gave a rate of 0.01 cases of embolism per million. The rate rose to 1.5 cases per million for those travelling more than 5000km.

Dr Baker was recently involved in designing a study to be conducted by the Australasian Society of Thrombosis and Haemostasis and aviation medicine experts at Griffith University, which he said would investigate such aspects in more detail.