Does Your Office Have "Sick Building Syndrome?"

During the last 20 years, concerns associated with the quality of the indoor office environment have escalated in the American workplace. The National Institute for Occupational Safety and Health (NIOSH) has seen the number of requests for the Institute's assistance rise dramatically, as public concern about this problem continues to increase.

What is Indoor Environmental Quality (IEQ)?

The public is probably more familiar with the terms "Indoor Air Quality" and "Sick Building Syndrome." "Indoor Air Quality," as the name implies, simply refers to the quality of the air in an office environment. "Sick Building Syndrome" is a term many people use to convey a wide range of symptoms they believe can be attributed to the building itself. Workers typically implicate the workplace environment because their symptoms are alleviated when they leave the office.

NIOSH prefers to use the term "Indoor Environmental Quality" (or IEQ) to describe the problems occurring in office buildings and schools throughout the nation. The Institute, through its Health Hazard Evaluation (HHE) Program, evaluates potential health hazards in workplaces in response to requests from employers, employees, employee representatives, state and local government agencies, and Federal agencies. NIOSH investigators have found that concerns about air quality may be caused by a number of factors, encompassing much more than air contamination. Other factors such as comfort, noise, lighting, ergonomic stressors (poorly designed work stations and tasks) and job-related psychosocial stressors can individually and in combination contribute to complaints. Hence, IEQ more accurately describes the scope of the problem.

What are the typical symptoms associated with IEQ?

The symptoms reported to NIOSH have been diverse and usually not suggestive of any particular medical diagnosis. A typical spectrum of symptoms includes:

  • headaches,
  • unusual fatigue,
  • varying degrees of itching or burning eyes,
  • skin irritation,
  • nasal congestion,
  • dry or irritated throats, and;
  • nausea.

How big is the IEQ problem?

During the last decade, there has been a significant increase in public concern about IEQ. NIOSH scientists have completed approximately 1300 evaluations related to the indoor office environment since the late 1970's, and the percentage of the total number of requests has risen dramatically. In 1980, requests to evaluate office environments made up only 8% of the total requests for NIOSH investigations. In 1990, the Institute received 150 IEQ requests, which accounted for 38% of the total. Since 1990, IEQ requests have made up 52% all requests.

Why are IEQ problems increasing?

During the 1970's, ventilation requirements were changed to conserve fossil fuels, and virtually air-tight buildings emerged. At the same time, a revolution occurred in office work throughout the country. Computers and other new work technologies forced a change in office procedures and productivity, and ergonomic and organizational stress problems may have increased. Coupled with the conservation measures and changing technology was a dramatic increase in the number of workers in white collar jobs. Greater awareness of the potential for IEQ problems may also be contributing to a rise in reporting of suspected problems. All of these factors may have contributed to the increase.

Media coverage of IEQ has profoundly influenced the number of IEQ requests the Institute receives. Following a network television report on the subject in October 1992, NIOSH received over 6,000 phone calls and nearly 800 requests for investigations.

What types of IEQ problems has NIOSH found in the workplace?

NIOSH investigators have found IEQ problems caused by ventilation system deficiencies, overcrowding, offgassing from materials in the office and mechanical equipment, tobacco smoke, microbiological contamination, and outside air pollutants. NIOSH has also found comfort problems due to improper temperature and relative humidity conditions, poor lighting, and unacceptable noise levels, as well as adverse ergonomic conditions, and job-related psychosocial stressors.

What is typically involved in an investigation?

Evaluation of a potential hazard can involve various methods of investigation. These include:

  • direct observation of production processes and work practices,
  • measurement of contamination levels and extent of employee exposure,
  • medical testing or physical examinations,
  • confidential interviews, and;
  • review of employer's records of injuries and illnesses, medical tests, and job histories.

What do investigators look for during an IEQ evaluation?

NIOSH investigators typically look at four elements to determine if there is an IEQ problem.

  1. Pollutant sources: Is there a source of contamination or discomfort indoors, outdoors, or within the mechanical systems in the building?

  2. The Heating, Ventilating, and Air Conditioning System (HVAC) system: Can the HVAC system control existing contaminants and ensure thermal comfort? Is it properly maintained and operated?

  3. Pollutant pathways and driving forces: The HVAC system is the primary pathway. Are the pressure relationships maintained between areas of the building so that the flow of the air goes from cleaner areas to dirtier areas?

  4. Occupants: Do the building occupants understand that their activities affect the air quality?

NIOSH investigators then look at factors beyond air quality including physical factors, such as lighting, vibration, noise, ergonomic factors, and psychosocial aspects of the workplace.

What help is available in solving IEQ problems?

Many IEQ problems can be solved with in house expertise. NIOSH, in conjunction with the Environmental Protection Agency (EPA), has published a guide to provide help in solving these problems. This publication, Building Air Quality: A Guide for Building Owners and Managers (22,728 KB in .PDF format), provides practical advice for evaluating IEQ problems. In addition, many local and state health departments, as well as private firms, have expertise in evaluating IEQ problems.

NIOSH through its Health Hazard Evaluation (HHE) Program, evaluates potential health hazards in workplaces in response to requests from employers, employees, employee representatives, state and local government agencies and Federal agencies.

However, because of the extraordinary number of IEQ requests, NIOSH is not able to conduct a site visit in response to every request. NIOSH will evaluate each request and respond within the constraints of available resources.

You may also contact NIOSH at 1-800-35-NIOSH (1-800-356-4674)
fax 513-533-8573.

The above information has been provided with the kind permission of the Centers for Disease Control (

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Last Editorial Review: 12/1/2003