Indoor pollution
sources release gases or particles into the air and are the primary cause of indoor
air quality problems in homes. Inadequate ventilation can increase indoor pollutant
levels by not brining in sufficient outside air to dilute emissions from indoor
sources and by not carrying indoor air pollutants out of the home. High temperature
and humidity levels can also increase concentrations of some pollutants.
Pollutant
sources:
There are many potential sources of indoor air pollution in any home. These sources
fall into several categories: oil, gas, kerosene, coal, or wood combustion sources;
building materials and furnishings as diverse as deteriorated asbestos-containing
insulation, wet or damp carpeting, and cabinetry or furniture made of certain
pressed wood products; products for household cleaning and maintenance, personal
care, or hobbies; central hearing and cooling systems and humidification devices;
and outside sources such as radon, pesticides, and outdoor air pollution.
The relative importance of any single source depends on how much of a given pollutant
if emits and how hazardous those emissions are. In some cases, factors such as
how old the sources if and whether it id properly maintained are significant.
For example, an improperly adjusted gas stove can emit significantly more carbon
monoxide than one that is properly adjusted.
Some sources, such as building materials, furnishings, and household products
such as air fresheners, release pollutants more or less continuously. Other sources
related to activities carried out in the home, release pollutants intermittently.
Such activities include smoking, the use of unvented or malfunctioning stoves,
furnaces, or space heaters, the use of solvents in cleaning and hobby activities,
the use of paint strippers in redecorating activities, and the use of cleaning
products and pesticides in the housekeeping. High pollutant concentrations can
remain in the air for long periods after some of these activities.
Amount
of ventilation
If too little outdoor air enters a home, pollutants can accumulate to levels that
can pose health and discomfort problems. Unless they are built with special mechanical
means of ventilation, homes that are designed and constructed to minimize the
amount of outside air hat can "leak" into and out of the home may have
higher pollutant levels than other homes. However, because some weather conditions
can drastically reduce the amount of outside air that enters a home, pollutants
can build up even in homes that are normally considered "leaky."
Reference
Guide to Major Indoor Air Pollutants in the Home
Biologicals
Sources: Wet or moist walls, ceilings, carpets, and furniture; poorly maintained
humidifiers, dehumidifiers, and air conditioners; bedding; household pets
Health Effects: Eye, nose, and throat irritation; shortness of breath;
dizziness; lethargy; fever; digestion problems. Asthma; humidifier fever; influenza
and other infectious diseases
Carbon
Monoxide
Sources: Unvented kerosene and gas heaters; leaking chimneys and furnaces;
down drafting from wood stoves and fireplaces; gas stoves. Automobile exhaust
from attached garages. Environmental tobacco smoke
Health Effects:
At low concentrations, fatigue in healthy people and chest pain in people with
heart disease. At higher concentrations, impaired vision and coordination; headaches;
dizziness; confusion; nausea. Can cause flu-like symptoms that clear up after
leaving home. Fatal at very high concentrations.
Nitrogen
Dioxide
Sources: Kerosene heaters, unvented gas stoves and heaters. Environmental
tobacco smoke.
Health Effects: Eye, nose, and throat irritation; may cause impaired lung
function and increased respiratory infections in young children.
Respirable
particles
Sources: Fireplaces, wood stoves, and kerosene heaters. Environmental tobacco
smoke.
Health Effects: Eye, nose, ad throat irritation; respiratory infections
and bronchitis; lung cancer.
Organic
Gases
Sources: Household products including: paints, paint strippers, and other
solvents; wood preservatives; aerosol sprays; cleansers and disinfectants; moth
repellants and air fresheners; stored fuels and automotive products; hobby supplies;
dry cleaned clothing.
Health Effects: Eye, nose, and throat irritation; headaches, loss of coordination,
nausea, damage to liver, kidney, and central nervous system. Some organics can
cause cancer in animals; some are suspected or known to cause cancer in humans.
Formaldehyde
Sources: Pressed wood products (hardwood, plywood wall paneling, particleboard,
fiberboard) and furniture made with these pressed wood products. Urea-formaldehyde
foam insulation (UFFI). Combustion sources and environmental tobacco smoke. Durable
press drapes, other textiles, glues.
Health Effects: Eye, nose, and throat irritation; wheezing and coughing;
fatigue; skin rash; severe allergic reactions. May cause cancer. May also cause
other effects listed under "organic gases."
Pesticides
Sources: Products used to kill household pests (insecticides and termiticides).
Also, products used on lawns and gardens that drift or are tracked inside the
house.
Health Effects: Irritation to eye, nose, and throat; damage to central nervous
system and kidneys; cancer.
Asbestos
Sources: Deteriorating or damaged insulation, fire-proofing, or acoustical
materials.
Health Effects: No immediate symptoms. Chest and abdominal cancers and
lung diseases. Smokers are at higher risk of developing asbestos induced lung
cancer.
Lead
Sources: Automobile exhaust. Sanding or open flame burning of lead-based
paint. Activities involving lead solder.
Health Effects: Impaired mental and physical development in both fetuses
and young children. Decreased coordination and mental abilities; damage to kidneys
and nervous system, and red blood cells. May contribute to high blood pressure.
