- Indoor air quality can be worse than that of outdoor air.
- Problems can arise from moisture,
insects, pets, appliances, radon, materials used in household
products and furnishings, smoke and other sources.
- Effects range from minor annoyances
to major health risks.
- Remedies include ventilation, cleaning,
moisture control, inspections, and following manufacturers'
directions when using appliances and products.
Research has shown that the quality of indoor air can be worse
than that of outdoor air. Many homes are built or remodeled
more tightly, without regard to the factors that assure fresh
and healthy indoor air. Our homes today contain many furnishings,
appliances and products that can affect indoor air quality.
- Unusual and noticeable odors.
- Stale or stuffy air.
- Noticeable lack of air movement.
- Dirty or faulty central heating or air conditioning equipment.
- Damaged flue pipes or chimneys.
- Un-vented combustion air sources for fossil fuel appliances.
- Excessive humidity.
- Presence of molds and mildew.
- Health reaction after remodeling, weatherizing, using new
furniture, using household and hobby products, or moving
into a new home.
- Feeling noticeably healthier outside.
Poor indoor air can arise from many sources. At least some
of the following contaminants can be found in almost any home:
- Moisture and biological pollutants such
as molds, mildew, dust mites, animal dander and cockroaches
from high humidity levels, inadequate ventilation, and poorly
maintained humidifiers and air conditioners.
- Combustion products, including carbon
monoxide, from un-vented fossil fuel space heaters, un-vented
gas stoves and ovens, and back drafting from furnaces and
water heaters.
- Formaldehyde from durable press draperies
and other textiles, particle board products such as cabinets
and furniture framing, and adhesives.
- Radon, a radioactive gas from soil and
rock beneath and around the home's foundation, groundwater
wells and some building materials.
- Household products and furnishings such
as paints, solvents, air fresheners, hobby supplies, dry-cleaned
clothing, aerosol sprays, adhesives, and fabric additives
used in carpeting and furniture which can release volatile
organic compounds.
- Asbestos found in most homes more than
20 years old. Sources include deteriorating, damaged or disturbed
pipe insulation, fire retardant, acoustical material and
floor tiles.
- Lead from lead-based paint dust created
when removing paint by sanding, scraping or burning.
- Particulates
from dust and pollen, fireplaces, wood stoves, kerosene heaters
and un-vented gas space heaters.
- Tobacco smoke, which produces particulates,
combustion products and formaldehyde.
Paneling, pressed-wood furniture
and cabinetry. These products may release formaldehyde
gas.
Remedy: Ask about formaldehyde
content before buying furniture or cabinets. Some types of
pressed-wood products, such as those with phenol resin, emit
less formaldehyde. Also, products coated with polyurethane
or laminates may reduce formaldehyde emissions. After installation,
open windows. Maintain moderate temperature and humidity.
Carpet. Biological pollutants
can grow on water-damaged carpet. New carpet can release organic
gases.
Remedy: Promptly clean
and dry water-damaged carpet, or remove it altogether. If adhesives
are needed, ask for low-emitting ones. During installation,
open doors and windows, and use window fans or room air conditioners.
Vacuum regularly. Consider area rugs instead of wall-to-wall
carpet. Rugs are easier to remove and clean, and the floor
underneath also can be cleaned.
Floor tiles. Some
contain asbestos.
Remedy: Periodically inspect
for damage or deterioration. Do not cut, rip, sand or remove
any asbestos-containing materials. If you plan to make changes
that might disturb the asbestos, or if materials are more than
slightly damaged, contact a professional for repair or removal.
Call your local or state health department or the Environmental
Protection Agency.
Moisture. Moisture
encourages biological pollutants, including allergens such
as mold, mildew, dust mites and cockroaches.
Remedy: If possible, eliminate
moisture sources. Install and use exhaust fans. Use a dehumidifier
if necessary. Remove molds and mildew by cleaning with a solution
of chlorine bleach (1 cup bleach to 1 gallon water). Maintain
good fresh air with natural and mechanical air circulation.
Fireplace. Your
fireplace can be a source of carbon monoxide and combustion
pollutants.
Remedy: Open the flue when
using the fireplace. Have the flue and chimney inspected annually
for exhaust back drafting, flue obstructions or cracks, excess
creosote or other damage. Install smoke and carbon monoxide
detectors.
Air conditioner. This can
be a source of biological allergens.
Remedy: If there is a water
tray, empty and clean it often. Follow all service and maintenance
procedures, including changing the filter.
Gas or kerosene space heater. These
devices can release carbon monoxide and combustion pollutants.
Remedy: Never use un-vented
kerosene or gas space heaters. In the room where the heater
is located, provide fresh air by opening a door to the rest
of the house, turning on an exhaust fan and slightly opening
a window.
Tobacco smoke. Smoke contains
harmful combustion and particulate pollutants, including carbon
monoxide and combustion byproducts.
Remedy: Do not smoke in
your home or permit others to do so, especially near children.
If smoking cannot be avoided indoors, open windows or use exhaust
fans.
Draperies. New draperies
may be treated with a formaldehyde-based finish and emit odors
for a short time.
Remedy: Before hanging,
air draperies to ventilate odors. After hanging, ventilate
the area. Maintain moderate temperature and humidity.
Lead-based paint. Paint
manufactured before l978 may contain lead.
Remedy: Leave lead-based
paint undisturbed if it is in good condition. Before removing
paint, test for lead. Do-it-yourself lead test kits are available
from hardware or building supply stores. Do not sand, burn
off or remove lead-based paint yourself. Hire a person with
special training to correct lead-based paint problems. For
more information, call 1-800-LEAD-FYI.
Animals. Many animals leave
allergens, such as dander, hair, feathers or skin, in the air.
Remedy: Keep pets outdoors
as often as possible. Clean the entire house regularly. Deep
clean areas where pets are permitted. Clean pets regularly.
House dust mites. Biological
allergens can trigger asthma.
Remedy: Clean and vacuum
regularly. Wash bedding in hot water above 130 degrees F. Use
more hard-surface finishes; they are less likely to attract
and hold dust mites.
Household cleaners. Unhealthy
or irritating vapors may be released from chemicals in products.
Remedy: Select non-aerosol
and nontoxic products. Use, apply, store and dispose of them
according to manufacturers' directions. If products are concentrated,
label the storage container with dilution instructions. Completely
use up a product.
Pressed-wood cabinets. These
can be a source of formaldehyde vapor.
Remedy: Maintain moderate
temperatures (80 degrees maximum) and humidity (about 45 percent).
When purchasing new cabinets, select solid wood or metal cabinets
or those made with phenol resin; they emit less formaldehyde.
Ventilate well after installation.
Un-vented gas stove and range. These
are a source of carbon monoxide and combustion byproducts.
Remedy: Keep appliance
burners clean. Periodically have burners adjusted (blue flame
tip, not yellow). Install and use an exhaust fan. Never use
a gas range or stove to heat your home.
Personal care products. Organic
gases are released from chemicals in some products, such as
deodorant and hair sprays, shampoos, toners, nail polish and
perfumes.
Remedy: Select odor-free
or low odor-producing products. Select non-aerosol varieties.
Open a window, or use an exhaust fan. Follow manufacturers'
directions when using the product and disposing of containers.
Air freshener. These products
can release organic gases.
Remedy: Open a window or
use the exhaust fan instead. If you use air fresheners, follow
manufacturers' directions. Select natural products.
Humidifier/vaporizer. Cold
mist vaporizers can encourage biological allergens, including
mold, mildew and cockroaches, that can trigger asthma and encourage
viruses and bacteria.
Remedy: Use and clean them
according to manufacturers' directions. Refill daily with fresh
water.
Moth repellents. These
often contain the pesticide paradichlorobenzene.
Remedy: Avoid breathing
vapors. Place them in tightly sealed trunks or other containers.
Store separately, away from living areas.
Dry-cleaned goods. Chemicals
used in the cleaning process release organic gases.
Remedy: Bring odors to
the attention of your dry cleaner. Try to air out dry-cleaned
goods before bringing them indoors. Seek alternatives to dry
cleaning, such as hand washing items.
Un-vented clothes dryer. Gas
dryers produce carbon monoxide and combustion byproducts and
can be a fire hazard.
Remedy: Regularly dispose
of lint around and under the dryer. Provide air for gas units.
Vent the dryer directly to the outside. Clean vent and ductwork
regularly.
Gas or oil furnace/boiler and gas
water heater. Air quality problems include back
drafting of carbon monoxide and combustion pollutants.
Remedy: Have your heating
system and water heater, including gas piping and venting,
inspected every year.
Asbestos pipe wrap and furnace insulation. These
can release asbestos fibers into the air.
Remedy: Periodically look
for damage or deterioration. Do not cut, rip, sand or remove
any asbestos-containing materials. If you plan to make changes
that might disturb the asbestos, or if materials are more than
slightly damaged, contact a professional for repair or removal.
Ground moisture. Moisture
encourages biological allergens like mold and mildew.
Remedy: Inspect for condensation
on walls, standing water on the floor, or sewage leaks. To
keep basement dry, prevent outside water from entering by installing
roof gutters and downspouts, not watering close to the foundation,
grading soil away from the home, and applying waterproofing
sealants to basement interior walls. For standing water, consider
installing a sump pump. If sewage is the source, have drains
professionally cleaned. If moisture has no obvious source,
install an exhaust fan controlled by humidity levels. Remove
mold and mildew. Regularly clean and disinfect the basement
floor drain.
Radon. This invisible,
radioactive gas poses a lung cancer risk.
Remedy: Test your home
for radon. Do-it-yourself kits are easy and inexpensive. Have
an experienced radon contractor fix your home if your radon
level is 4 picocuries per liter (pCi/L) or higher. For more
information call 1-800-SOS-RADON.
Hobby products. Chemicals
in products such as solvents, paint, glue and epoxy release
organic gases.
Remedy: Follow manufacturers'
directions for use, ventilation, application, clean-up, and
container storage and disposal. Use outdoors when possible.
Indoors, open a window, or use an exhaust fan. Reseal containers
well. Clean tools outside or in a well-ventilated area.
Car and Small Engine Exhaust.
These are sources of carbon monoxide and combustion byproducts.
Remedy: Never leave vehicles,
lawn mowers, snowmobiles, etc., running in the garage.
Paint, solvent and cleaning supplies. These
products may release harmful vapors.
Remedy: Provide ventilation
when using them. Follow manufacturers' directions. Buy only
as much as you need. If the products contain methylene chloride,
such as paint strippers, use them outdoors. Reseal containers
well. Keep products in their original, labeled containers.
Clean brushes and other materials outside.
Pesticides and fertilizers. Yard
and Garden chemicals may be toxic.
Remedy: Use non-chemical
methods when possible. Follow manufacturers' directions for
mixing, applying, storing and using protective clothing.
Mix or dilute them outdoors. Provide ventilation when using
them indoors. Store them outside of the home in their original,
labeled containers. After using the product, remove your
shoes and clean your hands and clothing to avoid bringing
the chemicals into your home.
- Install a smoke detector in each bedroom or in the adjacent
hallway.
- If you have gas or other fossil fuel appliances in the
house, install carbon monoxide detectors in these locations.
- Combination smoke and carbon monoxide detectors are available.
- Check the batteries frequently.
- Amount of Ventilation
If too little outdoor air enters a home, pollutants can
accumulate to levels that can pose health and comfort problems.
Unless they are built with special mechanical means of ventilation,
homes that are designed and constructed to minimize the amount
of outdoor air that 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 outdoor air that enters a home, pollutants can build up
even in homes that are normally considered "leaky".
Outdoor air enters and leaves a house by: infiltration, natural ventilation,
and mechanical ventilation. In a process known as infiltration, outdoor air flows
into the house through openings, joints, and cracks in walls, floors, and ceilings,
and around windows and doors. In natural ventilation, air moves through opened
windows and doors. Air movement associated with infiltration and natural ventilation
is caused by air temperature differences between indoors and outdoors and by
wind. Finally, there are a number of mechanical ventilation devices, from outdoor-vented
fans that intermittently remove air from a single room, such as bathrooms and
kitchen, to air handling systems that use fans and duct work to continuously
remove indoor air and distribute filtered and conditioned outdoor air to strategic
points throughout the house. The rate at which outdoor air replaces indoor air
is described as the air exchange rate. When there is little infiltration, natural
ventilation, or mechanical ventilation, the air exchange rate is low and pollutant
levels can increase.
Health effects from indoor air pollutants may be experienced soon after
exposure or, possibly, years later.
Immediate effects may show up after a single exposure or
repeated exposures. These include irritation of the eyes,
nose, and throat, headaches, dizziness, and fatigue. Such
immediate effects are usually short-term and treatable. Sometimes
the treatment is simply eliminating the person's exposure
to the source of the pollution, if it can be identified.
Symptoms of some diseases, including asthma, hypersensitivity
pneumonitis, and humidifier fever, may also show up soon
after exposure to some indoor air pollutants.
The likelihood of immediate reactions to indoor air pollutants depends
on several factors. Age and pre-existing medical conditions are two important
influences. In other cases, whether a person reacts to a pollutant depends
on individual sensitivity, which varies tremendously from person to person.
Some people can become sensitized to biological pollutants after repeated exposures,
and it appears that some people can become sensitized to chemical pollutants
as well.
Certain immediate effects are similar to those from colds
or other viral diseases, so it is often difficult to determine
if the symptoms are a result of exposure to indoor air pollution.
For this reason, it is important to pay attention to the
time and place symptoms occur. If the symptoms fade or go
away when a person is away from home, for example, an effort
should be made to identify indoor air sources that may be
possible causes. Some effects may be made worse by an inadequate
supply of outdoor air or from the heating, cooling, or humidity
conditions prevalent in the home.
Other health effects may show up either years after exposure
has occurred or only after long or repeated periods of exposure.
These effects, which include some respiratory diseases, heart
disease, and cancer, can be severely debilitating or fatal.
It is prudent to try to improve the indoor air quality in
your home even if symptoms are not noticeable.
While pollutants commonly found in indoor air are responsible
for many harmful effects, there is considerable uncertainty
about what concentrations or periods of exposure are necessary
to produce specific health problems. People also react very
differently to exposure to indoor air pollutants. Further
research is needed to better understand which health effects
occur after exposure to the average pollutant concentrations
found in homes and which occurs from the higher concentrations
that occur for short periods of time.