Fluke 983 Fluke Airborne Particle Counters Provide Vital Information for Maint - Page 2

Sources of IAQ Problems in Healthcare Facilities The spread of infection through the indoor air is a serious potential problem in healthcare facilities. Such infections can stem from two sources: • Infectious agents produced by people inside the facility, such as Tuberculosis, Rubella (measles) and influenza • Agents normally present in the human environment that can endanger patients who have compromised immune systems. Such organisms include Aspergillus fumigatus, a common species of mold, and others. Other airborne particulates, such as inorganic materials and allergens, while capable of causing health problems, pose a lesser threat to patients. These contaminants will not be addressed in this document, though the air filtration and air pressure balancing techniques that help control biological pathogens can also control odors, dust and other non-viable air pollutants. To control the movement and spread of infectious agents, facility designers and managers establish special purpose spaces called Airborne Infection Isolation (AII) or patient isolation room, and Protective Environment (PE) facilities. In both of these special ventilation spaces, air pressures are regulated to move air from clean to dirty areas. The AII room would house a patient judged to be a source of airborne infection, such as Mycobacterium tuberculosis or measles virus. Vents draw air from the room and exhaust it outside the building. High efficiency particulate air (HEPA) filters may be used to help remove particles from the air. Makeup air flowing into the room is balanced so that the room remains under negative air pressure. Thus the direction of airflow under the door or when the door is opened is into the space, rather than out, helping contain infectious particles. The Protective Environment facility is designed to keep infectious agents out and protect immuno-suppressed patients and others, such as bone-marrow and organ-transplant patients and premature infants, who are especially vulnerable to opportunistic infectious agents. The CDCii recommends that PE facilities be maintained under positive air pressure, with directional airflow (from one side of the room, across the patient to the exhaust) and twelve or more air changes per hour. Clean air is supplied through HEPA filters, and pointof-use HEPA filters may also be used. Air flowing through an open door or leak moves out of the space, not in. 2 Fluke Corporation Airborne particle counters provide vital information for maintaining indoor air quality in healthcare facilities