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Causes of Sick Building Syndrome
A Word About Radon and Asbestos...
SBS and BRI are associated with acute or immediate health problems; radon and asbestos cause
long-term diseases which occur years after exposure, and are therefore not considered to be
among the causes of sick buildings. This is not to say that the latter are not serious health risks;
both should be included in any comprehensive evaluation of a building's IAQ.
See
www.epa.gov/radon
and
www.epa.gov/asbestos
The following have been cited causes of or contributing factors to sick building syndrome:
Inadequate ventilation:
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. Inadequate
ventilation, which may also occur if heating, ventilating, and air conditioning (HVAC) systems
do not effectively distribute air to people in the building, is thought to be an important factor in
SBS. In an effort to achieve acceptable 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 smoking lounges) depending on the activities that normally occur in that space (see
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. Environmental tobacco smoke contributes high levels of VOCs, other
toxic compounds, and respirable particulate matter. Research shows that some VOCs can cause
chronic and acute health effects at high concentrations, and some are known carcinogens. Low to
moderate levels of multiple VOCs may also produce acute reactions. 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. For more information,
see
VOCs
;
Carbon Monoxide
;
Formaldehyde
;
Nitrogen Dioxide
;
Respirable Particles
.
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