1.   Bad breath from recycled air?

2.   Boeing and airline industry officials insist that the recycled air presents no problems.

3.   They might be the last people in America capable of clearing their heads with the recycled air of an airplane.

4.   On most planes air is recycled every three to four minutes with half fresh air and half recycled air.

5.   The Mir space station will also be microbiologically screened during the linkup to detrmine if the recycled air and water have been contaminated by exposure to space radiation.