Amount of particles suspending in the cirulating air in operating theatres.

By using particle-counting machine, we studied the amount of particles suspending in the circulating air in 6 of our operating theatres, 5 at Siriraj Hospital and one at the Taksin Hospital. Particles of 0.5-5 µmin diameter were identified by the machine. The amount of the measured particles was 200,000-800,000 particles per cubic foot. The study showed that our figures were exceeding that of the standard and therefore better clean-room technology should be introduced.