Biological Pollutants in the Home
Outdoor air pollution in cities is a major
health problem. Much effort and money continues to be spent cleaning up
pollution in the outdoor air. But air pollution can be a problem where you
least expect it, in the place you may have thought was safest - your home.
Many ordinary activities such as cooking, heating, cooling, cleaning, and
redecorating can cause the release and spread of indoor pollutants at home.
Studies have shown that the air in our homes can be even more polluted than
outdoor air. Many Americans spend up to 90 percent of their time indoors,
often at home. Therefore, breathing clean indoor air can have an important
impact on health. People who are inside a great deal may be at greater risk
of developing health problems, or having problems made worse by indoor air
pollutants. These people include infants, young children the elderly and
those with chronic illnesses. Many factors determine whether pollutants in
your home will affect your health. They include the presence, use, and
condition of pollutant sources, the level of pollutants both indoors and
out, the amount of ventilation in your home, and your overall health.
What Are Biological Pollutants?
Biological pollutants are or were living
organisms. They promote poor indoor air quality and may be a major cause of
days lost from work or school, and of doctor and hospital visits. Some can
even damage surfaces inside and outside your house. Biological pollutants
can travel through the air and are often invisible. Some common indoor
biological pollutants are:
- Animal Dander (minute scales from hair,
feathers, or skin)
- Dust Mite and Cockroach parts
- Infectious agents (bacteria or viruses)
- Pollen
Some of these substances are in every home. It
is impossible to get rid of them all. Even a spotless home may permit the
growth of biological pollutants. Two conditions are essential to support
biological growth nutrients and moisture. These conditions can be found in
many locations, such as bathrooms, damp or flooded basements, wet appliances
(such as humidifiers or air conditioners), and even some carpets and
furniture. Modern materials and construction techniques may reduce the
amount of outside air brought into buildings which may result in high
moisture levels inside. Using humidifiers, unvented heaters, and air
conditioners in our homes has increased the chances of moisture forming on
interior surfaces. This encourages the growth of certain biological
pollutants.
The Scope Of The Problem
Most information about sources and health
effects of biological pollutants is based on studies of large office
buildings and surveys of homes in northern U.S. and Canada. These surveys
show that 30% to 50% of all structures have damp conditions which may
encourage the growth and buildup of biological pollutants. This percentage
is likely to be higher in warm, moist climates. Some diseases or illnesses
have been linked with biological pollutants in the indoor environment.
However, many of them also have causes unrelated to the indoor environment.
Therefore, we do not know how many health problems relate only to poor
indoor air.
Health Effects Of Biological Pollutants
All of us are exposed to biological pollutants.
However, the effects on our health depend upon the type and amount of
biological pollution and the individual person. Some people do not
experience health reactions from certain biological pollutants, while others
may experience one or more of the following reactions:
- Allergic
- Infectious
- Toxic
Except for the spread of infections indoors,
allergic reactions may be the most common health problem with indoor air
quality in homes. They are often connected with animal dander (mostly from
cats and dogs), with house dust mites (microscopic animals living in
household dust), and with pollen. Allergic reactions can range from mildly
uncomfortable to life-threatening, as in a severe asthma attack. Some common
signs and symptoms are:
- Watery eyes
- Runny nose and sneezing
- Nasal congestion
- Itching
- Coughing
- Wheezing and difficulty breathing
- Headache
- Fatigue
Health experts are especially concerned about
people with asthma. These people have very sensitive airways that can react
to various irritants, making breathing difficult. The number of people who
have asthma has greatly increased in recent years. The number of people with
asthma has gone up by 59 percent since 1970, to a total of 9.6 million
people. Asthma in children under 15 years of age has increased 41 percent in
the same period, to a total of 2.6 million children. The number of deaths
from asthma is up by 68 percent since 1979, to a total of almost 4,400
deaths per year.
Talking to Your Doctor
Are you concerned about the effects on your
health that may be related to biological pollutants in your home? Before you
discuss your concerns with your doctor, you should know the answers to the
following questions. This information can help the doctor determine whether
your health problems may be related to biological pollution.
- Does anyone in the family have frequent
headaches, fevers, itchy watery eyes, a stuffy nose, dry throat, or a
cough? Does anyone complain of feeling tired or dizzy all the time? Is
anyone wheezing or having difficulties breathing on a regular basis?
- Did these symptoms appear after you moved
to a new or different home?
- Do the symptoms disappear when you go to
school or the office or go away on a trip, and return when you come
back?
- Have you recently remodeled your home or
done any energy conservation work, such as installing insulation, storm
windows, or weather stripping? Did your symptoms occur during or after
these activities?
- Does your home feel humid? Can you see
moisture on the windows or on other surfaces, such as walls and
ceilings?
- What is the usual temperature in your
home? Is it very hot or cold?
- Have you recently had water damage?
- Is your basement wet or damp?
- Is there any obvious mold or mildew?
- Does any part of your home have a musty or
moldy odor?
- Is the air stale?
- Do you have pets?
- Do your house plants show signs of mold?
- Do you have air conditioners or
humidifiers that have not been properly cleaned?
- Does your home have cockroaches or
rodents?
Infectious diseases caused by bacteria and
viruses, such as flu, measles, chicken pox, and tuberculosis, may be spread
indoors. Most infectious diseases pass from person to person through
physical contact. Crowded conditions with poor air circulation can promote
this spread. Some bacteria and viruses thrive in buildings and circulate
through indoor ventilation systems. For example, the bacterium causing
Legionnaire's disease, a serious and sometimes lethal infection, and Pontiac
Fever, a flu-like illness, have circulated in some large buildings.
Toxic reactions are the least studied and
understood health problem caused by some biological air pollutants in the
home. Toxins can damage a variety of organs and tissues in the body,
including the liver, the central nervous system, the digestive tract, and
the immune system.
Checking Your Home
There is no simple and cheap way to sample the
air in your home to determine the level of all biological pollutants.
Experts suggest that sampling for biological pollutants is not a useful
problem-solving tool. Even if you had your home tested, it is almost
impossible to know which biological pollutant(s) cause various symptoms or
health problems. The amount of most biological substances required to cause
disease is unknown and varies from one person to the next. Does this make
the problem sound hopeless? On the
contrary, you can take several simple, practical
actions to help remove sources of biological pollutants, to help get rid of
pollutants, and to prevent their return.
Self-Inspection: A Walk Through Your
Home
Begin by touring your household. Follow your
nose, and use your eyes. Two major factors help create conditions for
biological pollutants to grow nutrients and constant moisture with poor air
circulation.
- Dust and construction materials, such as
wood, wallboard, and insulation, contain nutrients that allow biological
pollutants to grow. Firewood also is a source of moisture, fungi, and
bugs.
- Appliances such as humidifiers, kerosene
and gas heaters, and gas stoves add moisture to the air.
A musty odor, moisture on hard surfaces, or even
water stains, may be caused by:
- Air-conditioning units
- Basements, attics, and crawlspaces
- Bathrooms
- Carpets
- Heating and air-conditioning ducts
- Humidifiers and dehumidifiers
- Refrigerator drip pans
What You Can Do About Biological
Pollutants
Before you give away the family pet or move,
there are less drastic steps that can be taken to reduce potential problems.
Properly cleaning and maintaining your home can help reduce the problem and
may avoid interrupting your normal routine. People who have health problems
such as asthma, or are allergic, may need to do this and more. Discuss this
with your doctor.
Moisture Control
Water in your home can come from many sources.
Water can enter your home by leaking or by seeping through basement floors.
Showers or even cooking can add moisture to the air in your home. The amount
of moisture that the air in your home can hold depends on the temperature of
the air. As the temperature goes down, the air is able to hold less
moisture. This is why, in cold weather, moisture condenses on cold surfaces
(for example, drops of water form on the inside of a window). This moisture
can encourage biological pollutants to grow.
There are many ways to control moisture in your
home:
- Fix leaks and seepage. If water is
entering the house from the outside, your options range from simple
landscaping to extensive excavation and waterproofing. (The ground
should slope away from the house). Water in the basement can result from
the lack of gutters or a water flow toward the house. Water leaks in
pipes or around tubs and sinks can provide a place for biological
pollutants to grow.
- Put a plastic cover over dirt crawlspaces
to prevent moisture from coming in from the ground. Be sure crawlspaces
are well-ventilated.
- Use exhaust fans in bathrooms and kitchens
to remove moisture to the outside (not into the attic). Vent your
clothes dryer to the outside.
- Turn off certain appliances (such as
humidifiers or kerosene heaters) if you notice moisture on windows and
other surfaces.
- Use dehumidifiers and air conditioners,
especially in hot, humid climates, to reduce moisture in the air, but be
sure that the appliances themselves don't become sources of biological
pollutants.
- Raise the temperature of cold surfaces
where moisture condenses. Use insulation or storm windows. (A storm
window installed on the inside works better than one installed on the
outside) Open doors between rooms (especially doors to closets which may
be colder than the rooms) to increase circulation. Circulation carries
heat to the cold surfaces Increase air circulation by using fans and by
moving furniture from wall corners to promote air and heat circulation.
Be sure that your house has a source of fresh air and can expel
excessive moisture from the home.
- Pay special attention to carpet on
concrete floors. Carpet can absorb moisture and serve as a place for
biological pollutants to grow. Use area rugs which can be taken up and
washed often. In certain climates, if carpet is to be installed over a
concrete floor, it maybe necessary to use a vapor barrier (plastic
sheeting) over the concrete and cover that with sub-flooring (insulation
covered with plywood) to prevent a moisture problem.
- Moisture problems and their solutions
differ from one climate to another. The Northeast is cold and wet, the
Southwest is hot and dry, the South is hot and wet, and the Western
Mountain states are cold and dry. All of these regions can have moisture
problems. For example, evaporative coolers used in the Southwest can
encourage the growth of biological pollutants. In other hot regions, the
use of air conditioners which cool the air too quickly may prevent the
air conditioners from running long enough to remove excess moisture from
the air. The types of construction and weather for the different
climates can lead to different problems and solutions.
Where Biological Pollutants May Be Found
in the Home
- Dirty air conditioners
- Dirty humidifiers and/or dehumidifiers
- Bathroom without vents or windows
- Kitchen without vents or windows
- Dirty refrigerator drip pans
- Laundry room with unvented dryer
- Unventilated attic
- Carpet on damp basement floor
- Bedding
- Closet on outside wall
- Dirty heating/air conditioning system
- Dogs or cats
- Water damage (around windows, the roof or
the basement)
Maintain And Clean All Appliances That
Come In Contact With Water
- Have major appliances, such as furnaces,
heat pumps and central air conditioners, inspected and cleaned regularly
by a professional, especially before seasonal use. Change filters on
heating and cooling systems according to manufacturer's directions. (In
general, change filters monthly during use.) When first turning on the
heating or air conditioning at the start of the season, consider leaving
your home until it airs out.
- Have window or wall air-conditioning units
cleaned and serviced regularly by a professional, especially before the
cooling season. Air conditioners can help reduce the entry of
allergy-causing pollen. But they may also become a source of biological
pollutants if not properly maintained. Clean the coils and rinse the
drain pans according to manufacturer's instructions, so water cannot
collect in pools.
- Have furnace-attached humidifiers cleaned
and serviced regularly by a professional, especially before the heating
season.
- Follow manufacturer's instructions when
using any type of humidifier. Experts differ on the benefits of using
humidifiers. If you do use a portable humidifier (approximately 1 to 2
gallon tanks), be sure to empty its tank every day and refill with
distilled or demineralized water, or even fresh tap water if the other
types of water are unavailable For larger portable humidifiers, change
the water as recommended by the manufacturer. Unplug the appliance
before cleaning. Every third day, clean all surfaces coming in contact
with water with a 3% solution of hydrogen peroxide, using a brush to
loosen deposits Some manufacturers recommend using diluted household
bleach for cleaning and maintenance, generally in a solution of one-half
cup bleach to one gallon water When any household chemical, rinse well
to remove all traces of chemical before refilling humidifier.
- Empty dehumidifiers daily and clean often.
If possible, have the appliance drip directly into a drain. Follow
manufacturer's instructions for cleaning and maintenance. Always
disconnect the appliance before cleaning.
- Clean refrigerator drip pans regularly
according to manufacturer's instructions. If refrigerator and freezer
doors don't seal properly, moisture may build up and mold can grow.
Remove any mold on door gaskets and replace faulty gaskets.
Clean Surfaces
- Clean
moist surfaces, such as showers and kitchen counters.
- Remove mold from walls, ceilings, floors,
and paneling. Do not simply cover mold with paint, stain, varnish, or a
moisture-proof sealer, as it may resurface.
- Replace moldy shower curtains, or remove
them and scrub well with a household cleaner and rinse before rehanging
them.
Dust Control
Controlling dust is very important for people
who are allergic to animal dander and mites. You cannot see mites, but you
can either remove their favorite breeding grounds or keep these areas dry
and clean. Dust mites can thrive in sofas, stuffed chairs, carpets, and
bedding. Open shelves, fabric wallpaper, knickknacks, and venetian blinds
are also sources of dust mites. Dust mites live deep in the carpet and are
not removed by vacuuming. Many doctors suggest that their mite-allergic
patients use washable area rugs rather than wall-to-wall carpet.
- Always wash bedding in hot water (at least
130° F) to kill dust mites. Cold water won't do the job. Launder
bedding at least every 7 to 10 days.
- Use synthetic or foam rubber mattress pads
and pillows, and plastic mattress covers if you are allergic. Do not use
fuzzy wool blankets, feather or wool-stuffed comforters, and feather
pillows.
- Clean rooms and closets well, dust and
vacuum often to remove surface dust. Vacuuming and other cleaning may
not remove all animal dander, dust mite material, and other biological
pollutants. Some particles are so small they can pass through vacuum
bags and remain in the air. If you are allergic to dust, wear a mask
when vacuuming or dusting. People who are highly allergy-prone should
not perform these tasks. They may even need to leave the house when
someone else is cleaning.
Before You Move
Protect yourself by inspecting your potential
new home. If you identify problems, have the landlord or seller correct them
before you move in, or even consider moving elsewhere.
- Have professionals check the heating and
cooling system, including humidifiers and vents. Have duct lining and
insulation checked for growth.
- Check for exhaust fans in bathrooms and
kitchens. If there are no vents, do the kitchen and bathrooms have at
least one window a piece? Does the cook top have a hood vented outside?
Does the clothes dryer vent outside? Are all vents to the outside of the
building, not in attics or crawlspaces?
- Look for obvious mold growth throughout
the house, including attics, basements, and crawlspaces and around the
foundation. See if there are many plants close to the house,
particularly if they are damp and rotting. They are a potential source
of biological pollutants. Downspouts from roof gutters should route
water away from the building.
- Look for stains on the walls, floor or
carpet (including any carpet over concrete floors) as evidence of
previous flooding or moisture problems. Is there moisture on windows and
surfaces? Are there signs of leaks or seepage in the basement?
- Look for rotted building materials which
may suggest moisture or water damage.
- If you or anyone else in the family has a
pet allergy, ask if any pets have lived in the home.
- Examine the design of the building.
Remember that in cold climates, overhanging areas, rooms over unheated
garages, and closets on outside walls may be prone to problems with
biological pollutants.
- Look for signs of cockroaches. (Carefully
read instructions for use and any cautionary labeling on cleaning
products before beginning cleaning procedures.)
- Do not mix any chemical products.
Especially, never mix cleaners containing bleach with any product (such
as ammonia) which does not have instructions for such mixing When
chemicals are combined, a dangerous gas can sometimes be formed.
- Household chemicals may cause burning or
irritation to skin and eyes.
- Household chemicals may be harmful if
swallowed, or inhaled.
- Avoid contact with skin, eyes, mucous
membranes and clothing.
- Avoid breathing vapor. Open all windows
and doors and use an exhaust fan that sends the air outside.
- Keep household chemicals out of reach of
children.
- Rinse treated surface areas well to remove
all traces of chemicals.
Correcting Water Damage
What if damage is already done? Follow these
guidelines for correcting water damage:
- Throw out mattresses, wicker furniture,
straw baskets and the like that have been water damaged or contain mold.
These cannot be recovered.
- Discard any water-damaged furnishings such
as carpets, drapes, stuffed toys, upholstered furniture and ceiling
tales, unless they can be recovered by steam cleaning or hot water
washing and thorough drying.
- Remove and replace wet insulation to
prevent conditions where biological pollutants can grow.
Reducing Exposure to Biological
Contaminants
General good housekeeping, and maintenance of
heating and air conditioning equipment, are very important. Adequate
ventilation and good air distribution also help. The key to mold control is
moisture control. If mold is a problem, clean up the mold and get rid of
excess water or moisture. Maintaining the relative humidity between 30% -
60% will help control mold, dust mites, and cockroaches. Employ integrated
pest management to control insect and animal allergens. Cooling tower
treatment procedures exist to reduce levels of Legionella and other
organisms.
Install and use exhaust fans that are vented to
the outdoors in kitchens and bathrooms and vent clothes dryers outdoors.
These actions can eliminate much of the moisture that builds up from
everyday activities. There are exhaust fans on the market that produce
little noise, an important consideration for some people. Another benefit to
using kitchen and bathroom exhaust fans is that they can reduce levels of
organic pollutants that vaporize from hot water used in showers and
dishwashers. Ventilate the attic and crawl spaces to prevent moisture
build-up. Keeping humidity levels in these areas below 50 percent can
prevent water condensation on building materials.
If using cool mist or ultrasonic humidifiers,
clean appliances according to manufacturer's instructions and refill with
fresh water daily. Because these humidifiers can become breeding grounds for
biological contaminants, they have the potential for causing diseases such
as hypersensitivity pneumonitis and humidifier fever. Evaporation trays in
air conditioners, dehumidifiers, and refrigerators should also be cleaned
frequently.
Thoroughly clean and dry water-damaged carpets
and building materials (within 24 hours if possible) or consider removal and
replacement. Water-damaged carpets and building materials can harbor mold
and bacteria. It is very difficult to completely rid such materials of
biological contaminants.
Keep the house clean. House dust mites, pollens,
animal dander, and other allergy-causing agents can be reduced, although not
eliminated, through regular cleaning. People who are allergic to these
pollutants should use allergen-proof mattress encasements, wash bedding in
hot (130° F) water, and avoid room furnishings that accumulate dust,
especially if they cannot be washed in hot water. Allergic individuals
should also leave the house while it is being vacuumed because vacuuming can
actually increase airborne levels of mite allergens and other biological
contaminants. Using central vacuum systems that are vented to the outdoors
or vacuums with high efficiency filters may also be of help.
Take steps to minimize biological pollutants in
basements. Clean and disinfect the basement floor drain regularly. Do not
finish a basement below ground level unless all water leaks are patched and
outdoor ventilation and adequate heat to prevent condensation are provided.
Operate a dehumidifier in the basement if needed to keep relative humidity
levels between 30 - 50 percent.
Health Effects From Biological Contaminants
Some biological contaminants trigger allergic
reactions, including hypersensitivity pneumonitis, allergic rhinitis, and
some types of asthma. Infectious illnesses, such as influenza, measles, and
chicken pox are transmitted through the air. Molds and mildews release
disease-causing toxins. Symptoms of health problems caused by biological
pollutants include sneezing, watery eyes, coughing, shortness of breath,
dizziness, lethargy, fever, and digestive problems.
Allergic reactions occur only after repeated
exposure to a specific biological allergen. However, that reaction may occur
immediately upon re-exposure or after multiple exposures over time. As a
result, people who have noticed only mild allergic reactions, or no
reactions at all, may suddenly find themselves very sensitive to particular
allergens. Some diseases, like humidifier fever, are associated with
exposure to toxins from microorganisms that can grow in large building
ventilation systems. However, these diseases can also be traced to
microorganisms that grow in home heating and cooling systems and
humidifiers. Children, elderly people, and people with breathing problems,
allergies, and lung diseases are particularly susceptible to disease-causing
biological agents in the indoor air. Mold, dust mites, pet dander, and pest
droppings or body parts can trigger asthma. Biological contaminants,
including molds and pollens can cause allergic reactions for a significant
portion of the population. Tuberculosis, measles, staphylococcus infections,
Legionella and influenza are known to be transmitted by air.
Combustion Pollutants
Combustion appliances are those which burn
fuels for warmth, cooking, or decorative purposes. Typical fuels are gas,
both natural and liquefied petroleum (LP), kerosene; oil, coal, and wood.
Examples of the appliances are space heaters, ranges, ovens, stoves,
furnaces, fireplaces, water heaters, and clothes dryers. These appliances
are usually safe. However, under certain conditions, these appliances can
produce combustion pollutants that can damage your health, or even kill
you.
What are Combustion Pollutants?
Combustion pollutants are gases or particles
that come from burning materials. The combustion pollutants come from
burning fuels in appliances. The types and amounts of pollutants produced
depend upon the type of appliance, how well the appliance is installed,
maintained, and vented, and the kind of fuel it uses. Some of the common
pollutants produced from burning these fuels are carbon monoxide, nitrogen
dioxide, particles, and sulfur dioxide. Particles can have hazardous
chemicals attached to them. Other pollutants that can be produced by some
appliances are unburned hydrocarbons and aldehydes. Combustion always
produces water vapor. Water vapor is not usually considered a pollutant, but
it can act as one. It can result in high humidity and wet surfaces.
Where do Combustion Pollutants Come
From?
Combustion pollutants found indoors include
outdoor air, tobacco smoke, exhaust from car and lawn mower internal
combustion engines, and some hobby activities such as welding, woodburning,
and soldering. Combustion pollutants can also come from vented or unvented
combustion appliances. These appliances include space heaters, gas ranges
and ovens, furnaces, gas water heaters, gas clothes dryers, wood or
coal-burning stoves, and fireplaces. As a group these are called
"combustion appliances."
Appliances
Vented appliances are appliances designed to be
used with a duct, chimney, pipe, or other device that carry the combustion
pollutants outside the home. These appliances can release large amounts of
pollutants directly into your home, if a vent is not properly installed, or
is blocked or leaking. Unvented appliances do not vent to the outside, so
they release combustion pollutants directly into the home. Look at the box
below for typical appliance problems that cause the release of pollutants in
your home. Many of these problems are hard for a homeowner to identify. A
professional is needed.
What are the Health Effects of
Combustion Pollutants?
The health effects of combustion pollutants
range from headaches and breathing difficulties to death. The health effects
may show up immediately after exposure or occur after being exposed to the
pollutants for a long time. The effects depend upon the type and amount of
pollutants and the length of time of exposure to them. They also depend upon
several factors related to the exposed person. These include the age and any
existing health problems. There are still some questions about the level of
pollutants or the period of exposure needed to produce specific health
effects. Further studies to better define the release of pollutants from
combustion appliances and their health effects are needed.
The sections below discuss health problems
associated with some common combustion pollutants. These pollutants include
carbon monoxide, nitrogen dioxide, particles, and sulfur dioxide. Even if
you are healthy, high levels of carbon monoxide can kill you within a short
time. The health effects of the other pollutants are generally more subtle
and are more likely to affect susceptible people. It is always a good idea
to reduce exposure to combustion pollutants by using and maintaining
combustion appliances properly.
Carbon Monoxide:
Each year, according to CPSC, there are more
than 200 carbon monoxide deaths related to the use of all types of
combustion appliances in the home. Exposure to carbon monoxide reduces the
blood's ability to carry oxygen. Often a person or an entire family may not
recognize that carbon monoxide is poisoning them. The chemical is odorless
and some of the symptoms are similar to common illnesses. This is
particularly dangerous because carbon monoxide's deadly effects will not be
recognized until it is too late to take action against them. Carbon monoxide
exposures especially affect unborn babies, infants, and people with anemia
or a history of heart disease. Breathing low levels of the chemical can
cause fatigue and increase chest pain in people with chronic heart disease.
Breathing higher levels of carbon monoxide causes symptoms such as
headaches, dizziness, and weakness in healthy people. Carbon monoxide also
causes sleepiness, nausea, vomiting, confusion, and disorientation. At very
high levels it causes loss of consciousness and death.
Nitrogen Dioxide:
Breathing high levels of nitrogen dioxide causes
irritation of the respiratory tract and causes shortness of breath. Compared
to healthy people, children, and individuals with respiratory illnesses such
as asthma, may be more susceptible to the effects of nitrogen dioxide. Some
studies have shown that children may have more colds and flu when exposed to
low levels of nitrogen dioxide. When people with asthma inhale low levels of
nitrogen dioxide while exercising, their lung airways can narrow and react
more to inhaled materials.
Particles:
Particles suspended in the air can cause eye,
nose, throat, and lung irritation. They can increase respiratory symptoms,
especially in people with chronic lung disease or heart problems. Certain
chemicals attached to particles may cause lung cancer, if they are inhaled.
The risk of lung cancer increases with the amount and length of exposure.
The health effects from inhaling particles depend upon many factors,
including the size of the particle and its chemical make-up.
Sulfur Dioxide:
Sulfur dioxide at low levels of exposure can
cause eye, nose, and respiratory tract irritation. At high exposure levels,
it causes the lung airways to narrow. This causes wheezing, chest tightness,
or breathing problems. People with asthma are particularly susceptible to
the effects of sulfur dioxide. They may have symptoms at levels that are
much lower than the rest of the population.
Other Pollutants:
Combustion may release other pollutants. They
include unburned hydrocarbons and aldehydes. Little is known about the
levels of these pollutants in indoor air and the resulting health effects.
What do I do if I suspect that
combustion pollutants are affecting my health?
If you suspect you are being subjected to carbon
monoxide poisoning get fresh air immediately. Open windows and doors for
more ventilation, turn off any combustion appliances, and leave the house.
You could lose consciousness and die from carbon monoxide poisoning if you
do nothing. It is also important to contact a doctor immediately for a
proper diagnosis. Remember to tell your doctor that you suspect carbon
monoxide poisoning is causing your problems. Prompt medical attention is
important. Some symptoms from combustion pollutants - headaches, dizziness,
sleepiness, coughing, and watery eyes - may also occur because of common
medical problems. These medical problems include colds, the flu, or
allergies. Similar symptoms may also occur because of other indoor air
pollutants. Contact your doctor for a proper diagnosis.
How can I reduce my exposure to
combustion pollutants?
Proper selection, installation, inspection and
maintenance of your appliances are extremely important in reducing your
exposure to these pollutants. Providing good ventilation in your home and
correctly using your appliance can also reduce your exposure to these
pollutants. Additionally, there are several different residential carbon
monoxide detectors for sale. These detectors would warn consumers of harmful
carbon monoxide levels in the home. They may soon be widely available to
reduce deaths from carbon monoxide poisoning.
Appliance Selection
- Choose vented appliances whenever
possible.
- Only buy combustion appliances that have
been tested and certified to meet current safety standards. Examples of
certifying organizations are Underwriters Laboratories (UL) and the
American Gas Association (AGA) Laboratories. Look for a label that
clearly shows the certification.
- All currently manufactured vented gas
heaters are required by industry safety standards to have a safety
shut-off device. This device helps protect you from carbon monoxide
poisoning by shutting off an improperly vented heater.
- Check your local and state building codes
and fire ordinances to see if you can use an unvented space heater, if
you consider purchasing one. They are not allowed to be used in some
communities, dwellings, or certain rooms in the house.
- If you must replace an unvented gas space
heater with another, make it a new one. Heaters made after 1982 have a
pilot light safety system called an oxygen depletion sensor (ODS). This
system shuts off the heater when there is not enough fresh air, before
the heater begins producing large amounts of carbon monoxide. Look for
the label that tells you that the appliance has this safety system.
Older heaters will not have this protection system.
- Consider buying gas appliances that have
electronic ignitions rather than pilot lights. These appliances are
usually more energy efficient and eliminate the continuous low-level
pollutants from pilot lights.
- Buy appliances that are the correct size
for the area you want to heat. Using the wrong size heater may produce
more pollutants in your home and is not an efficient use of energy.
- All new wood stoves are EPA-certified to
limit the amounts of pollutants released into the outdoor air. For more
information on selecting, installing, operating, and maintaining wood
burning stoves, write to the EPA Wood Heater Program. Before buying a
wood stove check your local laws about the installation and use of wood
stove
Ventilation
To reduce indoor air pollution, a good supply of
fresh outdoor air is needed. The movement of air into and out of your home
is very important. Normally, air comes through cracks around doors and
windows. This air helps reduce the level of pollutants indoors. This supply
of fresh air is also important to help carry pollutants up the chimney,
stovepipe, or flue to the outside.
- Keep doors open to the rest of the house
from the room where you are using an unvented gas space heater or
kerosene heater, and crack open a window. This allows enough air for
proper combustion and reduces the level of pollutants, especially carbon
monoxide.
- Use a hood fan, if you are using a range.
They reduce the level of pollutants you breath, if they exhaust to the
outside. Make sure that enough air is coming into the house when you use
an exhaust fan. If needed, slightly open a door or window, especially if
other appliances are in use. For proper operation of most combustion
appliances and their venting system, the air pressure in the house
should be greater than that outside. If not, the vented appliances could
release combustion pollutants into the house rather than outdoors. If
you suspect that you have this problem you may need the help of a
qualified person to solve it.
- Make sure that your vented appliance has
the vent connected and that nothing is blocking it. Make sure there are
no holes or cracks in the vent. Do not vent gas clothes dryers or water
heaters into the house for heating. This is unsafe.
- Open the stove's damper when adding wood.
This allows more air into the stove. More air helps the wood burn
properly and prevents pollutants from being drawn back into the house
instead of going up the chimney. Visible smoke or a constant smoky odor
inside the home when using a wood burning stove is a sign that the stove
is not working properly. Soot on furniture in the rooms where you are
using the stove also tells this. Smoke and soot are signs that the stove
is releasing pollutants into the indoor air.
Correct Use of Appliances
- Read and follow the instructions for all
appliances so you understand how they work. Keep the owner's manual in a
convenient place to refer to when needed. Also, read and follow the
warning labels because they tell you important safety information that
you need to know. Reading and following the instructions and warning
labels could save your life.
- Always use the correct fuel for the
appliance.
- Only use water-clear ASTM 1-K kerosene for
kerosene heaters. The use of kerosene other than 1-K could lead to a
release of more pollutants in your home. Never use gasoline in a
kerosene heater because it can cause a fire or an explosion. Using even
small amounts of gasoline could cause a fire.
- Use seasoned hardwoods (elm, maple, oak)
instead of softwoods (cedar, fir, pine) in wood burning stoves and
fireplaces. Hardwoods are better because they burn hotter and form less
creosote, an oily, black tar that sticks to chimneys and stove pipes. Do
not use green or wet woods as the primary wood because they make more
creosote and smoke. Never burn painted scrap wood or wood treated with
preservatives, because they could release highly toxic pollutants, such
as arsenic or lead. Plastics, charcoal, and colored paper such as
comics, also produce pollutants. Never burn anything that the stove or
fireplace manufacturer does not recommend.
- Never use a range, oven, or dryer to heat
your home. When you misuse gas appliances in this way, they can produce
fatal amounts of carbon monoxide. They can produce high levels of
nitrogen dioxide, too.
- Never use an unvented combustion heater
overnight or in a room where you are sleeping. Carbon monoxide from
combustion heaters can reach dangerous levels.
- Never ignore a safety device when it shuts
off an appliance. It means that something is wrong. Read your appliance
instructions to find out what you should do or have a professional check
out the problem.
- Never ignore the smell of fuel. This
usually indicates that the appliance is not operating properly or is
leaking fuel. Leaking fuel will not always be detectible by smell. If
you suspect that you have a fuel leak have it fixed as soon as possible.
In most cases you should shut off the appliance, extinguish any other
flames or pilot lights, shut off other appliances in the area, open
windows and doors, call for help, and leave the area.
Inspection and Maintenance
Have your combustion appliance regularly
inspected and maintained to reduce your exposure to pollutants. Appliances
that are not working properly can release harmful and even
fatal amounts of pollutants, especially carbon monoxide. Have chimneys and
vents inspected when installing or changing vented heating appliances. Some
modifications may be required. For example, if a change was made in your
heating system from oil to natural gas, the flue gas produced by the gas
system could be hot enough to melt accumulated oil combustion debris in the
chimney or vent. This debris could block the vent forcing pollutants into
the house. It is important to clean your chimney and vents especially when
changing heating systems.
What are the Inspection and Maintenance
Procedures?
The best advice is to follow the recommendations
of the manufacturer. The same combustion appliance may have different
inspection and maintenance requirements, depending upon where you live. In
general, check the flame in the furnace combustion chamber at the beginning
of the heating season. Natural gas furnaces should have a blue flame with
perhaps only a slight yellow tip. Call your appliance service representative
to adjust the burner if there is a lot of yellow in the flame, or call your
local utility company for this service. LP units should have a flame with a
bright blue center that may have a light yellow tip. Pilot lights on gas
water heaters and gas cooking appliances should also have a blue flame. Have
a trained service representative adjust the pilot light if it is yellow or
orange. Before each heating season, have flues and chimneys inspected and
cleaned before each heating season for leakage and for blockage by creosote
or debris. Creosote buildup or leakage could cause black stains on the
outside of the chimney or flue. These stains can mean that pollutants are
leaking into the house.