IMPROVING INDOOR AIR QUALITY: SOURCE REDUCTION
Energy conservation was strongly emphasized in the 1970âs,
following the oil crisis. The need to conserve energy led to reduced
ventilation rates. Buildings were sealed to exclude hot summer
air and cold winter air. Computers and other office technologies
led to more heat output, chemical hazards, and job stress.
By 1988, The National Institute for Occupational Safety and Health
(NIOSH) found that over 20% of its calls were about indoor air
quality. Of the over 500 investigations done by NIOSH, over 50%
had a primary problem of inadequate ventilation. The next most
common findings were inside contamination (15%), outside contamination
(10%), and building materials themselves (4%).
What kinds of things can be done?
Inside Source Reduction
· Sometimes cleaning compounds are used in higher concentrations
than are recommended by the manufacturer resulting in irritating
vapors. Recommended dilutions should be used.
· Carpets in heavy traffic areas can retain dust and chemical
residues. More frequent vacuuming, with appropriate filters, is
helpful in reducing dust levels. Carpet shampoos themselves can
be a source of contamination.
· Pesticides should only be applied when the building
is unoccupied. Offices should be thoroughly ventilated before
workers return to the building. Use of less toxic pesticides such
as boric acid for cockroaches may be appropriate.
· If smoking is allowed, separate well-ventilated areas
should be provided for that activity.
· Equipment that generates contaminants such as photocopiers
and laser printers should be equipped with local exhaust ventilation
so that the contaminants that they generate do not get into the
general ventilation system and spread throughout the building.
Carbonless copy paper and white-out (water-based is OK) can sometimes
Outside Source Reduction
· Fresh air intakes should not be located near sources
of air contamination such as loading docks where trucks may idle,
or near parking lots, or dumpster storage. Ventilation intakes
should not be located downwind of air exhausts or other sources.
Intakes or exhausts may need to be relocated or to have air cleaning
equipment installed. Fresh air must be clean.
· Construction (or demolition) such as roofing or paving,
office renovation such as knocking down walls, laying carpet,
painting, etc can create fumes or dusts. This work should be done
with proper controls when the offices are not occupied.
Control of Microbial Contamination
· Most frequently, microbial amplification follows water
damage to carpets, ceiling tiles and walls, or furnishings, or
standing water in the ventilation system.
· Any spills or leaks must be cleaned up promptly. to
prevent mold. If carpet, ceiling tiles or other porous materials
have become saturated with water, they should be dried within
48 hours. If this is not possible, wetted sections should be discarded
and replaced rather than disinfected.
· Non-porous surfaces where moisture has collected can
be cleaned and disinfected with detergents and bleach solutions.
· Drip pans in air condition units should be kept clean
and well-drained. Coiling coils should be regularly inspected
· Humidification may be needed to prevent excessive dryness,
but moisture can favor microbes that cause disease. Additives
to kill microbes can cause respiratory irritation. For central
humidification, dry steam systems are recommended. For smaller
units, fanatic attention to cleanliness is crucial