Friday, March 10, 2006

Poor air quality contributes to DVT on flights

So says research about to be published in the Lancet according to the Daily Telegraph. The proportion of oxygen in the air onboard aircraft is around 15% compared to 21% typically outside. This reduced amount of oxygen results in the blood thickening, increasing the propensity for clots.

Some of the measures you can take to avoid this include drinking plenty of water, because dehydration on board cabins exacerbates it. The usual advice about walking, taking aspirin with meals and not eating too much on board all apply, as does not sitting in cattle class (but that’s just about letting the blood swell around your ankles).

So it begs the question about what airlines or aircraft have better air quality. A fair rule of thumb is the newer the better. There used to be an “economy setting” installed on airliners to save fuel when passenger loads were light. Boeing states that it no longer offers an “economy setting” option for air conditioning on board its new aircraft. This includes all existing Boeing 777s and 747-400s and, of course, new ones. This covers a good proportion of flights from New Zealand. Boeing recommends airlines flying older aircraft operate air conditioning on full whenever passengers are carried (the “economy setting” was for flying empty or near empty).
.
I couldn’t find anything about it on the Airbus website, so can’t comment on them.

The new Boeing 787 (which Air NZ and Qantas have both ordered) will make a big difference. Humidity will be higher, and the cabin pressurisation will be as well – this should mean more oxygen and a safer, more pleasant flight. However, it will be about three years before you fly on one of those.

No comments: