(Adapted from the EPA publication “Office Building Occupants Guide to Indoor Air Quality” @ISBN 0-16-042729-0)
EPA – Indoor Air Quality: http://www.epa.gov/iaq/index.html
CDC – Facts About Mold: http://www.cdc.gov/mold/faqs.htm
What is Indoor Air Quality (IAQ)?
Indoor air quality refers to the quality of air in any given building location: The fundamental components that determine the quality of indoor air are the amount of oxygen, moisture/humidity, and the presence of airborne contaminants. However, the quality of indoor air is not defined, but rather a constantly changing interaction of complex factors that affects the types, levels, and importance of pollutants in indoor work environments. These factors include sources of pollutants or odors; design, maintenance and operation of building ventilation systems; moisture and humidity; and occupant perceptions and susceptibilities.
What factors affect IAQ?
Airborne contaminants can be generated by outdoor or indoor sources from a range of biological, chemical, or and/or particle substances:
- Biological sources include bacteria, viruses, fungi (including molds), dust mite allergen, animal dander, pollen, water spills, inadequate humidity control, and condensation.
- Sources of chemical contaminants include tobacco smoke, emissions (cleaning products, office furniture and equipment, wall and floor coverings), accidental chemical spill, and certain gases.
- Particle sources can be solid or liquid substances suspended in air. Particles of dust, dirt, or other substances may be drawn into the building from outside and can also be produced by activities that occur in buildings, like sanding wood or drywall, printing, copying, operating equipment, and smoking.
Contaminants can be generated from maintenance activities, pest control, housekeeping, renovation or remodeling, new furnishings or finishes, and building occupant activities. Common contaminants of indoor air are bacteria and fungi (molds, mildew, and yeasts).
How does IAQ affect building occupants?
Airborne contaminants are always present in air, but excessive concentrations may cause health problems to a building occupant(s) depending on their susceptibility. People react differently to various conditions; a number of environmental and personal factors can affect how people perceive air quality. Different factors influence how indoor air quality impacts building occupants. Some of these factors affect the types and levels of pollutants to which occupants may be exposed, and perception of air quality:
- Odors
- Temperature – too hot or too cold
- Air velocity and movement – too drafty or stuffy
- Heat or glare from sunlight
- Glare from ceiling lights, especially on monitor screens
- Furniture crowding
- Stress in the workplace or home
- Feelings about physical aspects of the workplace; location, work environment, availability of natural light, and the aesthetics of office design, such as color and style
- Work space ergonomics
- Noise and vibration levels
- Selection, location, and use of office equipment
How can good IAQ be maintained?
Good indoor air quality management practices are a shared responsibility between facilities managers, maintenance, housekeeping, and building occupants. Based on State Guidelines, Facilities Management monitors building temperatures and maintains temperatures between 72 – 78 degrees Fahrenheit. The HVAC work center in the Physical Plant maintains HVAC systems to ensure proper operation, and works to control humidity levels in buildings. General frequent housekeeping keeps work areas free of particle contaminants. Building occupants can also help prevent IAQ problems by practicing the following:
- Avoid blocking air vents or grilles.
- Smoke outdoors (University policy prohibits smoking in campus buildings), and at least 25’ from doors, open windows, and AC intake vents
- Clean all water spills promptly; report water leaks immediately
- Maintain office plants properly; do not overwater plants
- Dispose of garbage promptly and properly
- Store food properly
- Notify your building manager immediately if you suspect an IAQ problem
It is important to remember that some factors may not be within anyone’s immediate control. Any building, no matter how well operated, may experience periods of unacceptable IAQ due to maintenance, or in some cases, the actions of the building occupants. It is also important to keep in mind that sometimes perceived IAQ problems are often comfort problems, such as temperature, humidity, or air movement in a tight space. Symptoms such as headaches can have causes that are not related to factors in the building.
Acceptable indoor air quality for University of Maryland buildings has been defined as air in which there are no known contaminants at harmful levels, and with which 80% or more of the occupants do not suffer systematic discomfort. Air testing is provided by Environmental Health and Safety when evidence is suggested of the presence of contaminants.
