February 28 , 2002

IAQ: An Invisible, Yet Costly Threat to Human Health and Productivity

Peter Greaney, MD
Board-Certified Occupational Physician
President, WorkCare

Poor Indoor Air Quality (IAQ) is a national problem that has taken its toll on the health and productivity of the American workforce and its economy. The United States Environmental Protection Agency (EPA) declared it as one of the leading environmental threats to public health. IAQ experts and health and safety specialists confirm that it's a pressing issue in workplace health as demonstrated by their opinions in a recent survey. The survey, conducted by the American Industrial Hygiene Association, revealed that 40 percent of its respondents (composed of health and safety officers) cited indoor air quality as a primary issue. In addition to federal agencies and health and safety experts, the public as well is concerned with this issue. A nationwide survey by the Chelsea Group, a consulting group specializing in indoor environment services, shows that 70 percent of Americans are concerned that the quality of air in their homes and workplaces could have an adverse health impact.

This concern by individuals, scientists and federal health officials is understandable, given the fact 1 that nationwide medical costs are estimated at $188 million to $1.4 billion for illnesses related to poor IAQ. Indirect costs related to decreased productivity caused by IAQ problems have also burdened our economy. 2 One study found that for every 10 workers, poor IAQ caused an additional 6 sick days per year.

If left unchecked, IAQ problems at the workplace can result in expensive corrective action, facility shutdowns, employee lost time, disability and workers' compensation claims, increased absenteeism and decreased productivity.

Americans spend more than 90 percent of their working day indoors. Thus, as health and safety experts, it's important to recognize the resources we have to minimize the effects of poor IAQ in the workplace. This article provides an overview of causes, indicators and common ailments related to IAQ problems, as well as resources in developing an IAQ management plan.

According to the EPA, there are two common ailments associated with poor indoor air quality:

Sick Building Syndrome (SBS) 3 --This term is used to describe 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. The complaints may be localized in a particular room or zone, or may be widespread throughout the building.

Symptoms of SBS include:

• Headaches; eye, nose, or throat irritation; dry cough; dry or itchy skin; dizziness and nausea; difficulty in concentrating; fatigue; and sensitivity to odors.
• Most of those affected report relief after leaving the building.
• The cause of symptoms is not known.

Building Related Illness (BRI) --In contrast to SBS, BRI is a diagnosable illness that can be attributed directly to airborne building contaminants. Indicators of BRI include:

• Building occupants complain of symptoms such as cough; chest tightness; fever, chills; and muscle aches
• The symptoms can be clinically defined and have clearly identifiable causes.
• Complainants may require prolonged recovery times after leaving the building.

Multiple Chemical Sensitivity is another term often used when a person believes they are sensitive to very low concentrations of a variety of chemicals, and the exact diagnosis is rarely defined in this condition.

Factors that Contribute to Building Related Syndromes

There are multiple factors that can contribute to SBS, including inadequate ventilation, chemical contaminants from indoor sources, chemical contaminants from outdoor sources, and biological, from either indoors or outdoors sources.

Inadequate Ventilation:

Inadequate ventilation is a significant problem associated with poor indoor air quality. According to the National Institute for Occupational Safety and Health, poor ventilation is the primary cause in about 50 percent of all indoor air quality problems.

Ventilation is used to bring clean air into a building and exhaust stale indoor air out of the building. The process is performed through the building's heating, ventilation, and air-conditioning system (HVAC). If the HVAC system is not functioning properly or maintained, inadequate ventilation may occur. This may result in an uneven distribution of air to people in the building. The American Society of Heating, Refrigerating and Air-Conditioning Engineers recently revised its ventilation standard to provide a minimum 20 cfm/person in office spaces. Up to 60 cfm/person may be required in some spaces, see web site for additional standard information.

Uniformity of temperature is important for occupant comfort, and complaints about temperature and humidity are often clues to indoor air quality problems. According to the EPA, 4 temperature stratification is a common problem caused by convection, the tendency of light, warm air to rise, and heavier, cooler air to sink. If air is not properly mixed by the ventilation system, the temperature near the ceiling can be several degrees warmer or cooler than near the floor. Following is the ASHRAE Standard that details the temperature and humidity ranges that are comfortable for 80% of people engaged in largely sedentary activities.

Chemical Contaminants from Indoor Sources:

In the EPA's publication, Indoor Air Facts, sources from within a building are considered the leading cause of indoor air pollution. These sources include adhesives, carpeting, upholstery, manufactured wood products, copy machines, and pesticides. Cleaning agents may also emit volatile organic compounds (VOCs), including formaldehyde. Carbon monoxide can also be a source of IAQ problems. Carbon monoxide is an odorless, colorless, tasteless, and nonirritating gas. It is produced whenever carbon-based fuels are burned such as gas, oil, kerosene, wood, or charcoal. Carbon monoxide may also accumulate indoors as a result of tobacco smoking.

Chemical Contaminants from Outdoor Sources:

The outdoor air that enters a building can also be a source of indoor air pollution. For example, pollutants from motor vehicle exhausts; plumbing vents, and building exhausts (e.g., bathrooms and kitchens) can enter the building through poorly located air intake vents, windows, and other openings. In addition, combustion products can enter a building from a nearby garage.

Biological Contaminants:

Biological contaminants from indoor or outdoor sources may also be a cause of poor IAQ. These contaminants include bacteria, mold or pollen. These contaminants may breed in stagnant water that has been accumulating in ducts and humidifiers or where water has intruded in wall spaces, tile, carpeting or insulation. One indoor bacterium, Legionella, has caused both Legionnaire's Disease and a related condition, Pontiac Fever.

Overview in Developing an IAQ Management Plan

Although there are a variety of approaches in remedying an IAQ problem, it's essential to form a multi-disciplinary team composed of industrial hygienists, occupational health physicians, building owners, health and safety specialists, representative tenants, and facility staff. This team can use their expertise to develop an IAQ plan of action, and support communication efforts to keep occupants informed of the situation and progress on the IAQ management plan. Each member of the team has an important function in helping to resolve IAQ problems. A qualified medical physician can document symptoms experienced by the occupants and evaluate the potential for the symptoms to be caused by IAQ. Other resources, such as industrial hygienists and health and safety officers can apply their expertise to evaluate the HVAC system, look for evident problems and document the building's condition. Building owners and facility staff, along with tenants, will also be an important resource, providing observations and input regarding the IAQ problem.

The primary goal of any program should include a plan that focuses on identifying and resolving IAQ issues in a manner that prevents them from reoccurring, and avoids the creation of other problems. The following resources provide in-depth, step-by-step plans that are effective in combating IAQ problems:

List of links:

http://www.epa.gov/iaq/largebldgs/baqtoc.html
http://www.health.gov.au/pubhlth/publicat/document/env_indoorair.pdf
http://www.library.ca.gov/crb/01/notes/v8n1.pdf
http://www.epa.gov/iedweb00/pubs/sbs.html
http://www.aerias.com

1,2 Haymore C. and Odom, R. (1993). Economic Effects of poor IAQ. EPA Journal, October-December, 28-29.
3 U.S. EPA, Indoor Air Facts No. 4, (revised) Sick Building Syndrome.
4 Office of Radiation and Indoor Air Indoor Environments Division (6609J) EPA 402-K-95-001 (Second Edition) August 2000