The term "sick building syndrome" (SBS) 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.
A 1984 World Health Organization Committee report suggested that up to 30
percent of new and remodeled buildings worldwide may be the subject of excessive
complaints related to indoor air quality (IAQ). Often this condition is
temporary, but some buildings have long-term problems.
Sometimes indoor air problems are a result of poor building design and
maintenance or occupant activities.
• Building occupants complain of symptoms associated with
acute discomfort, e.g., headache; eye, nose, or throat irritation; dry cough; dry or itchy skin; dizziness and nausea; difficulty in
concentrating; fatigue; and sensitivity to odors.
• The cause of the symptoms is not known.
• Most of the complainants report relief soon after leaving the building.
• Building occupants complain of symptoms such as cough; chest tightness; fever,
chills; and muscle aches
|Causes of Sick Building Syndrome
The following have been cited causes of or contributing factors to sick building syndrome:
In the early and mid 1900's, building ventilation standards
called for approximately 15 cubic feet per minute (cfm) of
outside air for each building occupant, primarily to dilute and
remove body odors. As a result of the 1973 oil embargo, however,
national energy conservation measures called for a reduction in
the amount of outdoor air provided for ventilation to 5 cfm per
occupant. In many cases these reduced outdoor air ventilation
rates were found to be inadequate to maintain the health and
comfort of building occupants.
Achieve acceptable Indoor Air Quality (IAQ) while minimizing
energy consumption, the American Society of Heating,
Refrigerating and Air-Conditioning Engineers (ASHRAE) recently
revised its ventilation standard to provide a minimum of 15 cfm
of outdoor air per person (20 cfm / person in office spaces). Up
to 60 cfm/person may be required in some spaces (such as Food
court & pantry area, gaming zone, meeting & convention centres,
smoking lounges) depending on the activities that normally occur
in that space (As per ASHRAE Standard 62-1989).
Chemical contaminants from indoor sources:
Most indoor air pollution comes from sources inside the
building. For example, adhesives, carpeting, upholstery,
manufactured wood products, copy machines, pesticides, and
cleaning agents may emit volatile organic compounds (VOCs),
including formaldehyde. Combustion products such as carbon
monoxide, nitrogen dioxide, as well as respirable particles, can
come from unvented kerosene and gas space heaters, woodstoves,
fireplaces and gas stoves.
Research shows that some VOCs can cause chronic and acute health
effects at high concentrations, and some are known carcinogens.
Chemical contaminants from outdoor sources:
The outdoor air that enters a building can 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.
Bacteria, molds, pollen, and viruses are types of biological
contaminants. These contaminants may breed in stagnant water
that has accumulated in ducts, humidifiers and drain pans, or
here water has collected on ceiling tiles, carpeting, or
insulation. Sometimes insects or bird droppings can be a source
of biological contaminants.
Physical symptoms related to biological contamination include
cough, chest tightness, fever, chills, muscle aches, and
allergic responses such as mucous membrane irritation and upper
respiratory congestion. One indoor bacterium, Legionella, has
caused both Legionnaire's Disease and Pontiac Fever.
Solutions to Sick Building Syndrome
Solutions to sick building syndrome usually include combinations of the following:
1. Pollutant source
removal or modification is an effective approach to improve the
Indoor Air Quality.
2. Increasing ventilation rates and air distribution can be a
cost effective means of reducing indoor pollutant levels. HVAC
systems should be designed, at a minimum, to meet ventilation
standards in local building codes. In many buildings, IAQ can be
improved by operating the HVAC system to at least its design
standard, and to ASHRAE Standard 62-1989.
3. Air cleaning can be a useful adjunct to source control and
4. Education and communication are important elements in both
remedial and preventive indoor air quality management programs.
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.