Nosocomial transmission of Mycobacterium tuberculosis (MTb) is a recognized risk to health care workers in the U.S. In 1994, the U.S. Centers for Disease Control and Prevention (CDC) published Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-Care Facilities, 1994. (1) The Guidelines included recommendations for design and operation of Mfb isolation rooms.

Indoor climate affects occupational safety and comfort. When indoor climate conditions are on an optimum level, the number of accidents decrease while productivity and quality of the work increase. A new design guide for good indoor climate in commercial  kitchens is a result of the project "Research and Development Project of Commercial Kitchen Ventilation" started in 1996. Research pointed out that indoor climate conditions in commercial kitchens are not on an acceptable level

Quantitative and qualitative gas analysis is widely needed in present modern industrialized societies. The reasons for this need range from purely economical interests, to meeting the requirements of environmental and occupational health legislation. Examples of these applications include process effluent monitoring, emission monitoring, workplace safety monitoring, clinical blood gas monitoring, toxic gas monitoring in fires, chemical warfare agent detection and ambient air monitoring.

The presence of airborne contaminants in the production environment can create problems to products, production equipment and personnel. The improvement of the production environment is a complex task and therefore, unprofitable control measures are common. PIMEX and similar equipment (1-6) combines video picture of the work and simultaneously measured data from the sensors detecting e.g. airborne contaminants. Link between problem calling conditions and work can be analysed with the aid of video picture in which graphical presentation of data is superimposed.

The performance of an exterior hood is known to be affected by the cross draft (1, 2). Based on the knowledge from a classical "Rankin's nose" or "semi-infinite body" problem, in which the opening shrinks to a sink instead of a finite opening, the exhausted airflow combining the cross draft forms a capture envelope in front of the hood(3). All streamlines within the envelope lead to the hood opening, those outside of the envelope lead to infinity. Therefore, contaminant released inside the envelope tends to be captured by the hood; otherwise, it tends to escape beyond capture.