In the 1990s, it seemed that everyone was talking about sick building syndrome (SBS) — it was on the news, in the paper, and, of course, in trade magazines. Speculation was rife over what was causing symptoms such as headaches, dizziness, nausea, and fatigue in certain building occupants. After it came to light that inadequate ventilation was one of the primary causes of SBS, the HVAC industry started looking for solutions.
ASHRAE responded by creating Standard 62.1, “Ventilation for Acceptable Indoor Air Quality,” and the industry started taking a closer look at other possible causes of SBS, including volatile organic compounds (VOCs), proliferation of biological agents due to roofing or plumbing leaks and standing water in drain pans and ducts, radon, and air intakes placed near loading docks or parking garages. The industry worked hard to provide solutions for these — and other — issues, and after a few years, SBS gradually faded from the headlines. But SBS is far from being eradicated; indeed, it is still a concern that many HVAC professionals grapple with every day.
One reason why SBS is not discussed as frequently these days may be that a more specific term has emerged to describe a similar problem. Building related illness (BRI) is now used to describe specific symptoms that can be attributed to a known contaminant or irritant within the building, said Alex Stadtner, president and building biologist, Healthy Building Science, San Francisco. SBS is essentially a collection of unrelated symptoms that originate for an unknown reason in at least 20 percent of the a building’s occupants.
“BRI is generally an allergic reaction or infection, and specific symptoms include cough, chest tightness, fever, chills, and muscle aches. The symptoms may continue after occupants have left the building, and the cause of symptoms is known,” said Stadtner. “Humidifier fever, Legionnaires’ disease, skin rashes, hypersensitivity pneumonitis, and other illnesses related to bacteria, fungus (mold), and viruses are often classified as BRI, not SBS.”
By definition, SBS is unspecific, as one single factor cannot be identified as causing occupant symptoms, said Pawel Wargocki, Ph.D., associate professor at the Technical University of Denmark and chairman of ASHRAE’s Environmental Health Committee. “We know that poor indoor conditions are responsible for SBS symptoms, including thermal discomfort (temperatures that are too high), elevated exposures to contaminants due to poor source control and/or inadequate ventilation, etc. The symptoms are generally reported more often by women as well as in buildings with air conditioning. Poor maintenance and/or the presence of moisture in the HVAC systems is clearly the high risk factor for SBS symptoms.”
Because there are a number of indoor environmental conditions that can cause SBS, contractors may be reluctant to use such a broad term to describe a problem, said Ellis G. Guiles Jr., vice president and owner, TAG Mechanical Systems, Syracuse, New York. “For instance, over the last year, we’ve been working with a client whose building has an intermittent odor issue. Initially we wouldn’t call this SBS, but the odor has gotten worse over the last two years, and the occupants are complaining more frequently. Now, I would place it in the SBS category for the very simple fact that the building has an indoor environmental issue that is impacting the quality of the experience of people using the building.”
Better awareness may be another reason why we don’t hear much about SBS anymore. As Wargocki noted, “We know some of the potential risks, and we are attempting to deal with them; however, there is still a lot we have to do and learn. We need to be consistent and scrupulous and apply what we have learned so far about avoiding highly emitting materials and dirty ventilation filters, for example.”
There are many cases in which SBS symptoms could be mitigated, such as reducing ozone and the products of ozone chemistry indoors, said Wargocki. Distracting noise in open plan offices is another issue, as are temperatures that are too high. “Not to mention, too little attention is paid to the quality and maintenance of HVAC systems, which require not only regular cleaning, but also regular tests against the design values. Adequate ventilation is certainly important but should not be considered to be a ‘magic bullet’ that can solve all problems related with SBS symptoms. There are many other economical methods to make it happen.”
ASHRAE Standard 62.1 has also had an impact, as it has served to educate designers and builders about best practices for ventilation, said Stadtner. “It has helped tremendously in commercial buildings, because the vast majority of SBS/BRI cases do involve the ventilation system. Whether it’s insufficient or polluted outdoor air supply, inadequate exhaust of point-source contaminants that create cold spots for condensation and inadequate dehumidification, or simply the ventilation system creating the pressure or pathway for contaminants to traverse through a building — the ventilation system is almost always involved.”
A growing awareness of building science is slowly leading to better building techniques, as well, which may be reducing the cases of SBS. “I believe the most promising and exciting development in this arena is the establishment of clear standards for Building Enclosure Commissioning (BECx),” said Stadtner. “This system institutionalizes building science reviews into the design process and ensures quality control verification during installation of key elements that are common to building failures. It’s a great advancement that will revolutionize the commercial construction trades in the coming decades.”
Better building materials are another key element, as many of the early cases of SBS/BRI were related to items such as carpet and paint, which were off-gassing chemicals that created symptoms in occupants. “A growing movement toward healthy building materials and material ingredient transparency is helping to move the industry toward better alternatives,” said Stadtner. “We still get calls about new carpet or paint smells, and some occupants very clearly get headaches (BRI) from the off-gassing of some building materials. More stringent standards are unrolling every year, and I trust this trend will continue with top-down pressure [regulations] and bottom-up demand.”
Guiles noted that while many of his clients are becoming more aware and concerned about their comfort and IAQ, most building owners/managers still take a “wait until complaints” approach. “Even in buildings such as hospitals, where you would expect to find a more proactive approach, this doesn’t always happen because of economic factors being considered by the administrators.”
Another issue that may delay the diagnosis of SBS is the tendency of doctors to prescribe medication to treat symptoms rather than finding the underlying cause. Stadtner uses asthma as an example, noting that doctors have become much better at ameliorating the symptoms through modern medicine, but they do not always address the underlying cause. “When these kids tell their doctors that they feel worse in the morning or evening, the doctor tells them to use an inhaler before going to bed or right when they get up in the morning, rather than asking more detailed questions about why the symptoms are occurring at that time of day. Doctors should suggest an air quality inspection to identify and address the cause of the problem instead of simply medicating patients who so clearly suffer in one particular building.”
While better awareness has helped minimize issues related to poor indoor environmental quality, Guiles still sees far more buildings with HVAC systems that are not operating correctly and building envelopes that have problems. “This leads me to believe there are more issues than are really being discussed, and that the majority of people haven’t connected the dots between how they feel and the buildings they live, work, and play in.”
For this reason, SBS can be a great opportunity for HVAC contractors, who could be proactive and offer to perform testing and balancing on a regular basis for their customers in order to stay ahead of any problems. “Of course, contractors should be checking the drain lines and making sure the coils aren’t dirty and replacing the filters. But it’s also an opportunity for them to reengage with the owner about how the system is working and optimizing it over time,” said Stadtner.
And having that on-going conversation with building owners and managers is important because even with better building materials and more awareness, there will always be cases of BRI or SBS, said Wargocki. “There are many new buildings that are energy efficient, but people still complain. Contractors should, at a minimum, follow the recommendations in ASHRAE’s Indoor Air Quality Guide and GreenGuide and make sure their customers’ buildings are well commissioned and maintained. That will help, but unfortunately, new pollutants are introduced indoors at a very high rate, and many chemicals can be toxic and cause SBS. We only learn about them when people get sick in actual buildings.”
This means there will always be an opportunity in this area for contractors, because SBS/BRI can occur in any kind of building, and every market has a need for environmental assessments.
Publication date: 5/12/2014