Work-related stress, rather than building conditions, may be what's behind the constellation of symptoms known as "sick building syndrome," according to researchers.

In a study of more than 4,000 UK government employees, researchers found that high job demands and perceptions of poor support were more closely related to sick-building symptoms than were the physical conditions of the workplace.

The findings suggest that "sick building syndrome" may in fact be a misnomer, the researchers report in the journal Occupational and Environmental Medicine.

That does not mean the symptoms aren't real, but that the physical properties of the workplace may not be a major cause, according to study co-author Dr. Mai Stafford of University College London Medical School.

"The symptoms certainly exist," she stated, "and cost millions in lost productivity (and) sickness absence."

Sick building syndrome refers to a cluster of symptoms, including headache, nasal congestion, eye irritation and fatigue, that appear to arise when a person is in a particular indoor environment. Studies, however, have failed to find consistent connections between symptoms and specific physical conditions of buildings.

On the other hand, Stafford and her colleagues report, there is growing evidence that job stress -- especially the combination of demanding work and little autonomy -- has health effects, and that the physical reactions to stress are similar to the symptoms attributed to sick building syndrome.

The researchers analyzed data from 4,052 civil servants working in 44 buildings in London. Workers were surveyed about sick-building-type symptoms, as well as job stress and the conditions of their work space.

In some buildings, researchers took environmental measurements of temperature, humidity, dust, airborne fungus and bacteria, and other conditions.

Overall, there was some evidence that the heat and humidity of the workplace, as well as levels of dust and bacteria, were related to employees' symptoms.

But there was a much stronger relationship between symptoms and job stress -- namely, demanding work and a perceived lack of support from superiors and colleagues.

In addition, the researchers unexpectedly found a lower prevalence of symptoms at sites with poor air circulation and "unacceptable" levels of carbon dioxide, airborne fungi and chemicals known as volatile organic compounds.

None of this means that poor or uncomfortable physical conditions are acceptable in the workplace, the researchers add

Problems such as excessive heat and poor ventilation, they write, "can and should be improved even if health outcomes are unchanged."

And while building conditions in this study were not closely related to workers' symptoms, Stafford said some work sites may indeed have conditions that affect employees' health.

Stafford and her colleagues conclude that the findings suggest that the psychological and social environment of the workplace should be considered when workers are bothered by headaches, fatigue and other symptoms attributed to sick building syndrome.

SOURCE: Occupational and Environmental Medicine, April 2006.