The airlines should face up to long-haul health risks

Everyone knows now that there are worse dangers lurking in long-distance air travel than a bad inflight movie, air rage or jet lag. Deep vein thrombosis, or DVT, used to be a relatively obscure condition which mostly affected the bed-bound elderly. Recently, however, it has been renamed "economy class syndrome" and attention has been grabbed by a series of deaths of air passengers who could have come under the Lottery slogan, "It could be you".

Everyone knows now that there are worse dangers lurking in long-distance air travel than a bad inflight movie, air rage or jet lag. Deep vein thrombosis, or DVT, used to be a relatively obscure condition which mostly affected the bed-bound elderly. Recently, however, it has been renamed "economy class syndrome" and attention has been grabbed by a series of deaths of air passengers who could have come under the Lottery slogan, "It could be you".

Now a new study has found that one in 10 people who travel on eight-hour flights develop DVT but show no symptoms. The findings of the study have been challenged on the basis of the small sample and the possibility of unintentional bias. But it does at least suggest that, although the chance of dying from DVT as a result of air travel remains very small, the net of potential risk is spread wider than has been thought.

It also reinforces the point that there may be many more cases of people suffering from DVT as a result of air travel than have been detected, because of the sometimes long delay between the clot forming and it moving to the lungs, with often fatal consequences.

Most people know now, too, how important it is to move around on long flights, and that compression stockings are a good idea.

Whether or not the latest findings are confirmed, this new study draws attention to the fact that the airlines ­ whose safety record is generally exceptional ­ have been slow to respond to this health risk of their trade. This is not a comparable situation to the tobacco companies' knowledge of lung cancer, but the dangers of long periods of immobility have been known for at least 40 years, and it could be argued that the airlines should have carried out their own research long ago.

Once again, expensive litigation in the much-criticised US is forcing the pace. The airlines are now under not just a moral obligation but a legal one to act as quickly as possible to ensure that further research is carried out and to ensure that, in the meantime, all passengers are given sound advice on how to minimise the risks.