In the United States alone, almost 70 percent of the workforce works in indoor office settings, according to the National Institute for Occupational Safety and Health (NIOSH). And over the last two decades, a notable number of office workers around the world have reported symptoms related to their indoor environments.

In the 1970s, health care providers were faced with a rising number of people having headaches and allergic-like reactions to unspecified stimuli. In exploring these reactions over several years, the reactions were collectively called sick building syndrome (SBS), the symptoms of which are unknown.

SBS describes situations 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. SBS generally translates to more than 20 percent of a building's occupants experiencing the same or similar problems, although the complaints may be localized in a particular room or zone, or may be widespread throughout the building.

The term "building-related illness" (BRI), on the other hand, refers to situations when symptoms such as cough, chest tightness, fever, chills and muscle aches are diagnosable and can be attributed directly to airborne building contaminants.

Culprits of office buildings making workers sick could include the following:

• Inadequately filtered air conditioning;

• Chemical contaminants from indoor containments, such as adhesives, carpets, insulation, furniture that contains chloroform, cleaning agents, chemicals from photocopiers and laser printers;

• Chemical contaminants that can enter a building through windows or poorly located vents, such as vehicle exhaust fumes and plumbing fumes; and

• Biological contaminants, which tend to breed in stagnant water and in humid environments (air ducts, AC units, humidifiers), such as molds, bacteria, pollen and viruses that make their way into the air.

Radon, a naturally occurring radioactive gas found in soil, and asbestos, a material that was used in building materials, plastics and other products, are other possible building contaminants. Moreover, exposure to these pollutants tends to cause long-term health problems rather than immediate symptoms.

But there are solutions to potential reactions, the best approach being to first understand the reasons a building may be "sick."

First, it must be established that these symptoms are the result of SBS rather than allergies or chronic disease. A building investigation should identify and solve indoor air quality (IAQ) problems permanently while also preventing the creation of other problems. More often than not, reduced IAQ is the culprit. (See the Environmental Protection Agency's IAQ section.)

An investigator must figure out if a complaint is in fact related to IAQ, identify the cause of the complaint and determine the most appropriate corrective actions. This is done by collecting and reviewing existing records, conducting a walk-through inspection of the building to pinpoint a suspected source (or sources) of the problem and, finally, testing. (See the EPA's IAQ Management Checklist) It should be noted that air sampling for contaminants seldom provides information about possible causes.

Once the probable source (or sources) has been identified (assuming it/they has/have been identified), the next step is to remove or modify the pollutant source. The EPA offers the following approaches:

• Routine maintenance of heating, ventilating, and air conditioning (HVAC) systems;

• Replacing water-stained ceiling tile and carpeting;

• Venting contaminant source emissions to the outdoors;

• Instituting smoking restrictions;

• Storing and using paints, adhesives, solvents and pesticides in well-ventilated areas, and using them during periods of non-occupancy; and

• Allowing time for building materials in new or remodeled areas to off-gas pollutants before occupancy.

Increasing ventilation rates and air distribution can also be a cost-effective way of reducing indoor pollutant levels. (For detailed information on ventilation, read the EPA's Fact Sheet: Ventilation and Air Quality in Offices)

Air cleaning can be a useful means of sourcing control and ventilation, although it does have certain limitations.

According to the EPA:

Particle control devices such as the typical furnace filter are inexpensive but do not effectively capture small particles; high-performance air filters capture the smaller, respirable particles but are relatively expensive to install and operate. Mechanical filters do not remove gaseous pollutants. Some specific gaseous pollutants may be removed by adsorbent beds, but these devices can be expensive and require frequent replacement of the adsorbent material.

Finally, education and communication are critical elements in terms of remedying and preventing poor IAQ. "When building occupants, management and maintenance personnel fully communicate and understand the causes and consequences of IAQ problems, they can work more effectively together to prevent problems from occurring, or to solve them if they do," the EPA proposes.

Office workers don't seem to stand a chance of getting out of work alive. In addition to eye strain, carpal tunnel syndrome, stress, muscle pain and joint stiffness, workers must face the threat of the building itself during the daily grind. It's a matter of diagnosing and curing.

Both the EPA and NIOSH have air quality guidelines that building owners and managers can follow to improve conditions. And NIOSH can conduct investigations of potential health hazards at the request of employees or employers.

Resources

Indoor Air Facts: Sick Building Syndrome
U.S. Environmental Protection Agency

Indoor Environmental Quality
National Institute for Occupational Safety and Health

Ventilation and Air Quality in Offices
U.S. Environmental Protection Agency