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.
