Most Americans spend a great deal of time in the indoor environment, be it at home, school or work. While most people are aware of pollutants and the quality of the outdoor air, many people tend to forget about the quality of the air that they breathe when they are inside a building. The air inside of a building can contain a complex mixture of pollutants that originate both inside and outside of the building. The building’s ventilation system can play a major role in the presence or elimination of an indoor air quality issue. It can serve to dilute indoor pollutants as well as introduce outdoor pollutants into the environment. To conduct a thorough indoor air quality investigation, the investigator must understand the common pollutants associated with poor indoor air quality, the current age and health of the occupants, possible easily apparent sources, and whether or not the symptoms persist when away from the complaint area.
The link between some of the common indoor air pollutants (i.e. radon, particle pollution, carbon monoxide, Legionella bacterium, microbial contaminants, biological contaminants) and health effects has been very well established over the years by extensive research.
While adverse health effects have been attributed to some specific pollutants, the scientific understanding of some indoor air quality issues continues to evolve. One example is what is commonly known as "sick building syndrome," which occurs when building occupants experience similar symptoms after entering a particular building, with symptoms diminishing or disappearing after they leave the building. These symptoms are increasingly being attributed to a variety of building indoor air attributes. Researchers also have been investigating the relationship between indoor air quality and important issues not traditionally thought of as related to health, such as student performance in the classroom and productivity in occupational settings.
In addition, several other factors affect indoor air quality, including the air exchange rate, outdoor climate, weather conditions, and occupant behavior. The air exchange rate with the outdoors is an important factor in determining indoor air pollutant concentrations. The air exchange rate is affected by the design, construction, and operating parameters of buildings and is ultimately a function of infiltration (air that flows into structures through openings, joints, and cracks in walls, floors, and ceilings and around windows and doors), natural ventilation (air that flows through opened windows and doors), and mechanical ventilation (air that is forced indoors or vented outdoors by ventilation devices, such as fans or air handling systems).
Outdoor climate and weather conditions combined with occupant behavior can also affect indoor air quality. Weather conditions influence whether building occupants keep windows open or closed and whether they operate air conditioners, humidifiers, or heaters, all of which can affect indoor air quality. Certain climatic conditions can increase the potential for indoor moisture and mold growth if not controlled by adequate ventilation or air conditioning. Several key indoor air quality subjects will be covered in the presentation but since it is a complex and expanding field time will not allow all of the indoor air quality subjects to be covered in the time allotted for this presentation but can be further covered in a subsequent presentation.
According to the EPA, "a growing body of scientific evidence has indicated that the air within homes and other buildings can be more seriously polluted than the outdoor air in even the largest and most industrialized cities." Just about any building has the potential for periodic episodes of poor indoor air quality that can impact the health of the occupants. The U.S. Environmental Protection Agency (EPA) estimates that poor indoor air quality cost the nation billions of dollars in lost productivity and medical care. Properly responding to, diagnosing, and correcting the cause of indoor air quality complaints can have a positive impact on the occupant’s health and productivity.
Most often occupants' complaints are dismissed by building managers or investigated following a narrow approach that is commonly not focused on the appropriate area of the potential source and therefore is unable to resolve the issue. This produces a false negative for the complainant. The source of poor indoor air quality can be a complex combination of several factors and require a more analytical approach to properly diagnose the issue or propose an appropriate investigation plan. Being able to understand the building dynamics, design features and the effects they can have on the occupant’s health is key to improving the air quality in a building and addressing occupant’s complaints. In addition to understanding how a building functions it is important to be aware of the most common sources of indoor pollutants and how they impact the occupant's health.
This webinar will provide the attendees with important background information concerning the common causes of indoor air quality complaints, how to properly handle occupant complaints, investigate and test various air quality parameters, and provide steps that can be taken to improve the air quality for the building occupants.