Indoor Air Quality Frequently Asked Questions
How are chemical and biological
contaminants transported throughout a structure?
Molds and dust mites thrive in areas of high humidity. Mold grows on organic
materials such as paper, textiles, grease, dirt and soap scum. Mold spores float
throughout the house, forming new colonies where they land. Dust mites thrive on
dead human skin cells and in textiles such as bedding, carpeting and upholstery.
When these textiles are disturbed during vacuuming, making beds or walking on
carpet, the dust particles become airborne. Pollen, plant material that enters
through windows or on pets, and animal dander also become airborne when
disturbed. Infectious diseases caused by bacteria and viruses are generally
passed from person to person through physical contact, but some circulate
through indoor ventilation systems. Chemical contamination can come from
certain paints, varnishes, cleaning fluids, adhesives, plastics, furnishings,
even high tech electronic equipment.
How can I tell that indoor
air is contaminated?
Sniff the air. The nose is the best odor and gas detector, and a good particle
detector as well, especially when first entering a contaminated environment.
Unfortunately, in as little as 15 minutes, it adapts to the environment and
stops detecting contaminants. Chronic respiratory distress, headaches, and
fatigue may also be signs of contaminated air.
How can I detect whether my
indoor environment has significant concentrations of formaldehyde?
You may be able to detect it by its odor. Also, environmental testing firms,
listed in the yellow pages of the phone directory, should be able to test for
formaldehyde levels. Since such tests are costly, you should learn whether your
home has possible sources of formaldehyde. Also, do-it-yourself test kits are
available, but there is some question about their accuracy.
More information regarding Indoor Air Quality?
http://www.osha.gov/SLTC/indoorairquality/index.html
http://www.lungusa.org/site/apps/lk/links.aspx?c=dvLUK9O0E&b=36056
http://www.cdc.gov/niosh/topics/indoorenv/
http://www.nlm.nih.gov/medlineplus/indoorairpollution.html
http://www.cpsc.gov/cpscpub/pubs/iaq.html
http://www.treehugger.com/files/2007/10/green-basics-indoor-air-pollution.php
http://www.edfacilities.org/rl/iaq.cfm
Click the thumbnail image below to view a chart containing symptoms related to indoor air pollutants.
Volatile
- readily vaporized, rapidly changeable Organic
- Of, relating to, or derived from living organisms: organic matter. Compounds
- (In Chemistry,) consisting of atoms or ions of two or more different elements
in definite proportions that cannot be separated by physical meansWhat are MVOCs?
Some compounds produced by molds are volatile and are released directly into the
air. These are known as microbial volatile organic compounds (MVOCs). Because
these compounds often have strong and/or unpleasant odors, they can be the
source of odors associated with molds. Exposure to MVOCs from molds has been
linked to symptoms such as headaches, nasal irritation, dizziness, fatigue, and
nausea. Research on MVOCs is still in the early phase. The presence of airborne
microbial VOCs (MVOCs) may be a more reliable indicator of mold growth in
buildings than fungal spores. Approximately 150 air samples from a variety of
buildings including schools and commercial space have been evaluated for MVOCs.
All buildings were suspected to be contaminated with mold. The data show an
average MVOC indoor level of 50 mg/m3 with frequent detection of 2-octen-1-ol.
Since MVOCs can diffuse through barriers such as wallboard and plastics, mold
contamination can be detected even when visible growth is inaccessible.
What are the most common
MVOCs found in problem facilities?
Alternaria alternata and Aspergillus versicolor produced more MVOCs early (day
20), whereas the other four species produced more MVOCs at day 10. Penicillium
chrysogenum produced the highest total concentration (34 µg/m3); the greatest
number of individual MVOCs (six compounds) was produced by Aspergillus niger.
Emissions were also compared from three fresh (indoor) isolates of each species.
A. alternata isolates emitted 1, 2, or 5 MVOCs; total emissions of the lowest
emitting isolate was only 27% as much as the highest emitting isolate. Three
compounds were detected from all C. cladosporioides isolates; low:high was 4%.
All A. niger isolates emitted 4 MVOCs; low:high was 76%. One A. versicolor
strain emitted 6 MVOCs, and the other two emitted 3; low:high was 51%. Two P.
chrysogenum strains emitted 6 MVOCs, and the other released 5; low:high 43%. P.
brevicompactum strains produced either 5 (2) or 6 (1) MVOCs; the low:high was
37%. There is significant quantitative variation among isolates of these species
and, in four to six species; there were also qualitative differences.
What is formaldehyde?
It is a chemical that is released into the air as a pungent gas. It has a number
of useful properties; it's a good preservative and makes an excellent adhesive.
Therefore, it is used widely in the building and furnishings industries. It is
also found in small amounts in some textiles as an anti-wrinkle agent.
What are the major sources of
formaldehyde?
Particle board is the major contributor of formaldehyde to the indoor environment.
The culprit is the adhesive, urea formaldehyde, which can break down, releasing
the formaldehyde. Phenol formaldehyde (used in exterior panels) does not present
problems. Some particleboard is now manufactured with reduced formaldehyde.
Other sources include interior plywood, veneered or laminated furniture and
cabinets, some professionally applied furniture and floor finishes, paneling,
permanent press fabrics (some drapes), combustion products and cosmetics.
What are some of the
biological problems I should be concerned about?
Molds, mildew, fungi, bacteria and dust mites are some of the main biological
pollutants inside buildings. Some, such as pollen, are generated outside. Mold
and mildew are generated in the building and release spores into the air. Mold,
mildew, fungi and bacteria are often found in areas of the structure that have
high humidity levels, such as bathrooms, kitchens, laundry rooms or basements.
Dust mites and animal dander are problematic when they become airborne during
vacuuming, making beds or when textiles are disturbed.
What are some of the health
effects?
Allergic reactions are the most common health problems associated with
biological pollutants. Symptoms often include watery eyes, runny nose and
sneezing, nasal congestion, itching, coughing, wheezing and difficulty
breathing, headache, dizziness and fatigue. Dust mites have been identified as
the single most important trigger for asthma attacks.
What causes the "dirty sock"
smell in air handling systems?
The cause of the problem is the growth of mold and bacteria in the drain pan and
on the coils. Popular, energy-saving heat pumps are particularly susceptible to
this syndrome because their heating cycles are not hot enough to kill the
microbes that multiply during the cooling cycle and when the unit is idle. The
smell comes from the rich brew of microorganisms that breed in the drain pan
water. The slow warming of this contaminated water releases a plethora of spores
and toxins -- and the nasty smell -- into the air.
What can I do to prevent
indoor chemical and biological pollution?
o Fix leaky plumbing and leaks in the building envelope as soon as possible.
o Keep heating, ventilation, and air conditioning (HVAC) drip pans clean,
flowing properly, and unobstructed.
o Vent moisture-generating appliances, such as dryers, to the outside where
possible.
o Maintain low indoor humidity, below 60% relative humidity (RH), ideally
30-50%, if possible.
o Perform regular building/HVAC inspections and maintenance as scheduled.
o Clean and dry wet or damp spots within 48 hours.
o Don't let foundations stay wet. Provide drainage and slope the ground away
from the foundation.
o Clean and vacuum indoors frequently to minimize dust mites, mildew, mold,
fungi, bacteria and viral pollutants from building up. *HEPA filters and eco-friendly
cleaning solutions should be integrated.
o If building new, pretreat construction materials with EasyDECON to eliminate
concerns such as wet 'moldy' lumber, chemically treated materials and furnishings.
o When making purchases and decisions that will affect the quality of your
environment, be certain that you are choosing products and services that are
environmentally safe, non-toxic and sustainable.