Sick Building Syndrome (SBS) is a growing cause of concern for our modern day society. Any building has the potential for SBS, which can cause headaches, fatigue, and even mucous membrane irritation for those exposed to it. Even more serious is Building Related Illness (BRI), a medically identifiable disease which, in extreme cases, can cause physical impairment. Both Sick Building Syndrome and Building Related Illness are resultants of problems with a building’s indoor air quality (IAQ).
How widespread is the problem? A United States National Institute of Occupational Safety & Health survey concluded that only 12% of all non-residential buildings experience no problems with indoor air quality! Of the facilities with IAQ problems, 65% experience Sick Building Syndrome, with the remaining 35% experiencing both SBS and Building Related Illness. In the majority of SBS cases, the individual exposed experiences the symptoms only while at work; upon leaving the symptoms disappear. On the other hand, symptoms caused by BRI may last days, weeks, or even a lifetime.
Before we discuss causes of IAQ problems, it is appropriate to discuss the events leading up to the current state of IAQ awareness. First, Congress enacted legislation twice in the early 1990’s (Clean Air Act of 1990 & Indoor Air Quality Act of 1991) highlighting indoor air quality as a potential workplace hazard. Next came the constant reminders from the Surgeon General and American Cancer Society regarding the threats of tobacco smoke. Finally, the concerns with breathing asbestos and radon exposure have also increased public awareness and concern.
While indoor air quality problems are a cause of serious concern, there is also the potential for misdiagnosing worker problems as SBS. Psychological problems in the workplace caused by repetitive work, excessive work pace, and poor physical work environment, among others, can also lead to headaches and fatigue.
Causes of Indoor Air Quality Problems
A U.S. National Institute of Occupational Safety & Health survey looked at over 500 buildings to determine what, if any, factors lead to IAQ problems. Far and away the greatest cause is inadequate ventilation, prevalent in 52% of the buildings surveyed. Inadequate ventilation includes inadequate fresh air intake, poor temperature control, and low ventilation effectiveness. Next on the list at 16% is indoor contaminants, which are created by items such as tobacco smoke and photocopy machines. Third on the list is outdoor contaminants, like motor vehicle exhaust, which was found in 10% of the buildings. Rounding out the list are biological contaminants, 5%, and building fabric, 4%. Another 12% of buildings surveyed had no identifiable problem.
The Solution: Commissioning
The American Society of Heating, Refrigerating, and Air Conditioning Engineers recommends commissioning as a solution to Indoor Air Quality problems, with a five phase process.
Phase I: Program
For new construction, the first commissioning phase is the Program Phase. Reviews are conducted, evaluating intended occupant activities, densities, and locations within the facility, paying special attention to areas such as kitchens, break rooms, photocopy areas, meeting & conference rooms, smoking lounges, etc. Major outdoor sources of pollutants are identified, including cooling towers and exhaust systems. In some cases, prevailing winds and soil samples may even be taken into account. From this data, the need for supplemental exhaust can be identified.
Phase II: Design
Next, the design phase involves several steps. Manufacturer’s safety information is reviewed for products as diverse as carpet and flooring to paints, sealants, and fireproofing materials. HVAC equipment and insulation are reviewed for susceptibility to microbial contamination. Steps are taken to minimize standing water within the system—another source of microbial contamination. Systems are designed in accordance with all applicable IAQ codes and standards, and design intent is reviewed under all intended modes of operation. Additionally, design considerations include the incorporation of supplemental exhaust systems, as well as access to all doors and inspection ports within the air handling system.
Phase III: Construction
Activities during construction include review of the system component installation, verification that all critical components within the air handling system are accessible for cleaning, and review of temporary ventilation and filtration practices during construction. If the building remains partially occupied, the HVAC system should be operated to isolate occupied areas from construction areas.
Phase IV: Acceptance
During this phase, all HVAC filters and internals are inspected for cleanliness and readiness for operation; all air handling system components are tested for effective operation; materials and equipment are compared to the specifications to assure proper installation; and Test & Balance reports are reviewed and compared to design intent. Also during the fourth phase, spot checks are conducted for ventilation rates, air quality, and temperature and humidity control response.
Phase V: Post Acceptance
Finally, for at least one year after completion, periodic air quality tests are performed. The adoption of ventilation schedules is verified, and plans for post-commissioning IAQ testing are reviewed.
All parties are at risk to litigation surrounding indoor air quality problems. A team effort is essential for a successful project. With the financial concerns of lawsuits more prevalent than ever, coupled with the financial concerns of lower worker productivity and increased sick time due to indoor air quality problems, it is no longer a question of “Can we afford to fix our problem?”, but rather a question of “Can we afford not to?”