SCIENCE AND TECHNOLOGY: "Cleaning aircraft-cabin air: Breathing more easily; The air inside aircraft could soon be cleaner and more comfortable to breathe," The Economist, 19 September 2009.

Good news: much better tech coming on air filters for planes.

Planes are alleged to mix 50% new air with recycled, but to save money, some airlines (especially on long, overnight flights) drop it down to about 20% fresh air.

Reality is, even on short flights, you get to breathe the same air about 30 times. I could not welcome this news more.