In a previous article we discussed the difference between sick building syndrome (SBS) and building related illness (BRI). The first of these is a situation in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified. The second is when symptoms of diagnosable illness are identified and can be attributed directly to airborne building contaminants. In this article we will be examining the mystery surrounding sick building syndrome; identifying a variety of sources that can cause building occupants to complain of bad indoor air quality (IAQ) when no real problem is apparent.
In a paper written by Alan Hedge a professor of Design and Environmental Analysis at Cornell University the psychological aspects of indoor air quality are highlighted. First Hedge discusses how a person perceives IAQ, noting that there is usually a sensory process relying on the nose and mucus membranes to detect problems. He goes on to state, “Immediate odor judgments have been suggested as a metric for determining perceived indoor air quality in buildings. It is not clear whether this approach is sufficient because judgments of what are desirable and undesirable odors are influenced by personal preferences and beliefs. Unpleasant odors do not necessarily indicate hazardous indoor air and the absence of odors does not necessarily signify healthy air because many pollutants, like carbon monoxide, carbon dioxide, and airborne microorganisms have no odor.” Further more people tend to perceive warmer air with less circulation as less acceptable and therefore poor.
In the case of sick building syndrome, perception and occupant satisfaction play a significant role because in these cases there are vague symptoms which cannot be objectively measured. “SBS symptoms are linked to building occupancy because they get better on leaving the building. IAQ surveys of sick buildings often fail to find pollution problems, even though complaints are chronic and symptom prevalence among occupants is high with up to 80% of workers reporting at least one symptom.” Despite these findings poor IAQ is assumed the cause of symptoms since occupants get better once they leave the building. If said occupant was actually being exposed to pollutants while in the ‘sick building’ their symptoms would more than likely persist no matter where they were located.
One might ask, if not poor IAQ, then what? Quite simply, the mind is a very powerful tool which can lend itself to manifesting abnormal outcomes in peculiar situations. Hedge explains, “Belief and imagination processes work to influence what we create or choose as hypotheses to explain what we believe to be happening in the environment and inside our bodies. Once we believe that the air we are breathing contains a colorless, odorless, yet noxious pollutant which causes eye irritation, we will selectively attend to eye sensations for confirmation of exposure, and unconsciously we even may behave to create this information, by rubbing our eyes more frequently than normal thereby increasing irritation sensations. Such behaviors are, for example, quite common. If a person thinks about how itchy his/her nose is, they will eventually scratch it. If a person thinks about mites and fleas crawling over their body, they will eventually experience sensations of itchy skin and want to scratch.” Other factors that come into play are mass hysteria where symptoms will spread as people observe those around them being ‘sick’ and environmental stressors.
“Apart from finding that IAQ complaints and the SBS are significantly more prevalent in the air-conditioned than naturally ventilated offices there has been comparatively little research linking these problems to actual exposures to indoor air pollutants. Studies have found that environmental stress plays a significant role in the occurrence of problems. The extent to which physical environment stressors create strain and adverse health effects depends on the characteristics of exposed individuals and there ability to cope with these stressors.” Occupational factors (job level, hours of computer use, job stress, job satisfaction, handling of carbonless copy paper, photocopying), psychological factors (perceptions of control, perceptions of ambient conditions, perceptions of comfort), personal factors (gender), and organizational factors (public sector versus. private sector buildings), influence the prevalence of SBS symptoms among office workers.
This being said, the problem, be it real or imagined is a problem for the building owner since U.S ventilation standards specify that satisfactory IAQ is free from hazardous levels of contaminants AND satisfies 80% of the buildings occupants.
Katie Long
Power Vac America
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