The air in hospital wards with patients at high risk (Surgeries, Intensive Care Units and Bone Marrow Transplant Centers) has been surveyed less than the one in Operating Rooms. Microbic contamination of the air of those wards needs consistency of ventilation systems mainly  presence and location of HEPA absolute filters. Or dry air adhesive filters attached with central unit having pathogen killing gas or any chemical that has volatile action. Central filter units can check bacterial and aspergillar infection.  Ventilation systems are also equipped with absolute filters HEPA located centrally or peripherally, it can be outlined that the air quality from the point of view of both microbic and aspergillar contamination.   Hematology wards need safe UV lights and transfer rooms, and need  presence of artificial ventilation systems to cut down bacterial and fungal infection  with a ward with natural ventilation.

it is possible to measure the particles in the air during different phases of surgery. Thus the particle count (by which bacteria are transmitted, is a very good indicator.