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Indoor
Air Quality
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Indoor Air
Quality
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Indoor air pollution is a major
public health problem that threatens virtually all workers in
offices and buildings. Contaminated indoor air occurs when toxic
substances combine with inadequate building ventilation, causing
health problems such as eye, nose and throat irritation; sinus
discomfort; headaches; sneezing and coughing; respiratory infections;
and fatigue.
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What Are the Sources?
Poor indoor air quality can be
traced to many sources, including office equipment, furniture,
carpeting, and construction materials. In addition, buildings
are often designed or renovated without attention to ventilation,
resulting in sealed windows, blocked vents and a general lack
of fresh air.
Office Equipment
Electrical equipment such as
photocopiers may give off ozone, which irritates the eyes and
the respiratory tract, causes headaches, and has been shown to
cause adverse genetic effects. Ink toner in photocopying machines
use many dangerous substances including methyl alcohol, a solvent
which can dry the skin, irritate the eyes, nose and throat and
cause dizziness or even blindness.
Many common office supplies are
also dangerous, releasing vapors and dusts that can cause a variety
of skin and respiratory problems. These include glue, rubber
cement, inks, carbon paper, carbonless paper, typewriter ribbon,
and correction fluid.
Renovation and New Furnishings
A variety of solvents are used
in roofing, painting and renovation work and they can cause skin
dryness, respiratory irritation, and with greater exposure, dizziness
or nausea.
Formaldehyde one of the most common pollutants in
office buildings, is found in furniture, new carpets, particle
board, plywood, and many other products. As it deteriorates,
formaldehyde gives off fumes which - even at low levels - can
cause irritation of the eyes and respiratory system. Recent studies
show that prolonged exposure may also cause cancer.
Custodial and Maintenance
Work
Chemicals such as ammonia, solvents,
paint strippers and cleansers are widely used by custodians and
maintenance workers in the course of their jobs. Many of these
substances can lead to respiratory irritation, chronic lung disease,
and eye irritation. Making matters worse, these chemicals can
easily spread through the ventilation system, putting everyone
in the area at risk.
Two particularly dangerous groups
of chemicals are insecticides and pesticides. These highly toxic
substances can remain in the air long after being sprayed. They
are known to cause cancer and birth defects and they also irritate
the skin, eyes and lungs.
Biological Agents
Biological agents include bacteria,
viruses, fungi, pollen, dust mites and other insects, animal
dander (tiny scales from hair, feathers, or skin) and molds.
They can travel through the air and are often invisible. They
are usually inhaled, either alone or by attaching themselves
to particles of dust and then entering the respiratory system.
Two conditions are essential to support biological growth--nutrients
and moisture.
Bacteria, fungi and molds find
nourishment and can flourish in improperly maintained air ducts,
air conditioners, humidifiers, air-cleaning filters, carpets
and in improperly ventilated places where moisture is likely
to collect, such as bathrooms, kitchens, laundry rooms and basements.
Viruses can be carried indoors by people, while plants, pets
and insects are potential sources of pollen, dander, and other
allergies. Dust mites and other insects can thrive in sofas,
stuffed chairs, carpets and bedding.
When biological agents are allowed
to flourish in poorly maintained ventilation systems, severe
health problems can result that can be experienced throughout
an entire building. Infectious and noninfectious diseases can
be caused by the various biological agents. They can make you
sneeze, trigger allergic reactions, cause rashes, watery eyes,
hoarseness, coughing, dizziness, lethargy, breathing problems,
and digestive problems.
People with asthma are especially
susceptible to allergic problems caused by biological agents.
Exhaust and Cigarette Smoke
Diesel exhaust, containing carbon
monoxide and cancer-causing substances, can enter buildings
through improperly located air-intake vents or from loading
docks. Carbon dioxide causes headaches, dizziness and nausea,
and can be traced to many sources, including boiler gas and
cigarette smoke.
The outside environment may be
another source of indoor air pollution, particularly if toxic
vapors or gases from neighboring industrial plants or garbage
dumps enter the ventilation system.
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Ventilation
Systems
To eliminate indoor air pollution,
there must be a good source of fresh air as well as sufficient
air movement. Unfortunately, ventilation in both new and old
buildings is frequently inadequate. Most older buildings do not
have a mechanical ventilation system. While some fresh air may
enter through doors, windows and cracks, it is often not enough.
And during winter months or when energy conservation measures
are implemented, fresh air may be cut off entirely.
New buildings with sealed windows
present their own air quality problems, relying solely on mechanical
ventilation systems to bring outdoor air into the building and
move it to all areas. When the system fails because of contamination,
blockage or other problems, air quality may suffer dramatically.
To save energy, some buildings use ventilation systems which
recirculate air that has already been heated or cooled. The air
is passed through a filter, and sent back out through the building.
But the percentage of fresh air can be as low as 5-10% and in
the recirculated air, germs and chemical contaminants multiply,
significantly raising the risk of both irritation and infection.
To remove fumes and dust from
a specific operation, a local exhaust system is used. Examples
are the dust control system in a wood shop or ventilation hoods
in the chemistry lab. But these systems may create as many problems
as they solve. They may be weak, allowing pollutants to escape
into the general air supply, or they may pull toxic vapors through
an area where people breathe.
Every general ventilation system
consists of one or more blowers which move the air, ducts which
carry the air from one place to another, and vents which distribute
it. The vents may be either supplying air or removing (exhausting)
it.
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Evaluating Your
Ventilation System
- Does your workplace have
a ventilation system?
This is not as odd a question
as it may seem. Some buildings do not have ventilating systems.
You can check to see if yours does by walking around and looking
for vents and ducts.
- Is the system on all the
time?
Often, the air circulation in
a building will stop at 5 P.M. or on weekends even though people
may regularly work late or night shifts. In many offices, large
duplicating and printing jobs are done at night, and machines
can produce a high volume of pollutants.
You can test whether the system
is on by holding a tissue near the vent. If it moves, air is
being circulated. Do this before and after 5 P.M.
- Is the system continuous
or does it go on and off during the day?
Some ventilation systems are
on a time cycle. This means that the blower will turn on and
off at regular intervals throughout the day. If your workplace
is constantly generating air pollutants, such a system may not
be giving you enough fresh air. The pollutants may accumulate
while the system is off. Check the airflow regularly during the
day to find out if you are getting fresh air continuously.
- Does each room have a vent?
Walk around and make a listing
of the number of vents per room. Make sure you look on the walls
and floors--and remember, no vents, no air.
- Are the vents supplying or
removing air?
In each room there should always
be a supply and an exhaust vent. This type of ventilation system
is called dilution ventilation. You can determine which vents
are bringing air in and which are removing it by holding a tissue
at the face of the vent. If air is moving past, you will be able
to see it.
- Are the vents for supply
and exhaust right next to each other?
When supply and exhaust vents
are too close, the clean, fresh air gets sucked out of the room
before it has adequately circulated. This is called short-circuiting.
It is the result of poor engineering design, and is difficult
to repair.
- Are the vents blocked in
any way?
Exhaust and supply vents will
work only if the air can move freely around them. Blockage by
walls, partitions, or even piled up boxes or files, will obstruct
the air flow and reduce the ventilation efficiency.
- Are there any dead spaces
in your office?
Dead spaces are those in which
no air is replaced and in which pollutants will therefore build
up. You can check to see if there are any in your workplace office
by lighting a match and noticing how the smoke moves. (Caution
- be certain that an open flame is allowed in your workplace
and does not present a safety hazard.) Inexpensive smoke tubes
are also available for this purpose.
- Does the smoke flow toward
an exhaust vent or simply stay in one place?
If it doesn't move, pollutants
too will remain in the air; they are not being exhausted. The
principal reason for dead spaces is poor placement of supply
and exhaust vents.
- Do office areas with printing
and copying machines have adequate air supply and exhaust?
You can find out by counting
the vents, determining which way the air is moving and looking
for dead spaces. For some machines, general ventilation is insufficient.
You will need extra vents near the source of the fumes emitted.
- Do you have control over
your vent system?
Some offices make it possible
for workers to have control over the ventilation. You may be
able to enter the fan room and to turn the blower or fan supplying
the air up or down. Check with your building maintenance office
to see if you can do this.
- Is there a smoke detector
in your ventilation system?
There should be one. It is essential
for early signaling of a fire. The detector should be located
in the duct taking the air out of the office.
- Are the temperature and humidity
adequate?
The importance of a comfortable
temperature is obvious. But comfort also means proper humidity,
or water in the air. When the office air is too dry your nasal
passages dry up. You may get headaches and become more susceptible
to colds, flu, and other infections. When the air is too humid
you also feel uncomfortable. Humidity makes a cold room feel
colder and a hot room feel hotter.
Indoor Air Pollution Measurements
In order to determine just how
good or bad is the air in your office, you will have to test
it. You may test for
- the amount of air flow
- the amount and types of air
pollutants
- the amount of heat and moisture.
Some of these measurements are
easily determined while others require specialized equipment.
For flow measurements you will
need an airflow meter, also called a velometer. These are not
very expensive and are usually able to measure both air coming
into a room from the supply vent and air going out through the
exhaust vent.
Smoke tubes, which are available
in hardware stores, can also be used. But these will tell you
only where the air is going and not how much air is being moved.
The readings from a velometer
are in cubic feet per minute of air. The numbers should be:
|
Continuous exposure |
Air velocity (ft. per min.) |
|
Air conditioned space |
50-75 |
Fixed work station, general
ventilation or spot cooling:
|
sitting |
75-125 |
|
standing |
100-200 |
Intermittent exposure, spot
cooling or relief stations:
|
Light heat loads and activity |
1000-2000 |
|
Moderate heat loads and activity |
2000-3000 |
|
High heat loads and activity |
3000-4000 |
Your local health department
will usually set required minimum ventilation standards for office
buildings, but these standards vary from state to state. Check
with your state, county or city health department to see how
your workplace measures up to the health code, and if there is
a violation.
Measurement of specific air pollutants
usually requires very specialized instruments which may be difficult
to obtain. However, some pollutants you may want to look for,
even without exact measurements, are the following:
- Carbon monoxide--from cigarettes, gas heaters or any
cooking or burning. This is a chemical asphyxiant which robs
your body of needed oxygen and can cause headaches, nausea and
dizziness.
- Carbon dioxide--from insufficient air exchange. This
can also cause headaches, nausea, and dizziness.
- Ozone--from any machine that produces an electric
spark, such as a duplicating machine. This can be a respiratory
irritant.
- Smoke and dusts--from powders, burning substances, cigarettes.
These can cause eye and throat irritation, coughing and, if particularly
heavy, lung disease.
- Microbes (bacteria, fungi and viruses)--from
cooling water used in the ventilation system. These can cause
colds, influenza and such infectious diseases as Legionnaires
Disease.
- Oxides of nitrogen--from high temperature machines, hot
plates, cooking gas. These can cause watery eyes and irritations
of the respiratory system.
- Miscellaneous chemicals--such as solvents from glues, paints
and other office supplies, or chemicals used in duplicating machines,
such as toners, dyers and developers.
Measurements for temperature
and moisture are easily made. Temperature can be determined by
any common thermometer, but be sure that checks are made on such
places as exhaust vents, supply vents, halls and dead spaces.
Moisture can be measured by a
hydrometer, with the readings in percent relative humidity. The
higher the number, the more water is in the air and, usually,
the more discomfort there will be. But, as noted above, too low
a moisture reading can also be bad.
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How Can Indoor
Air Pollution Problems Be Solved?
What you can
push management to do:
Increase air supply. Clean and
maintain the ventilation system and open or unblock all sources
of fresh air.
Eliminate sources of contamination.
Substitute less dangerous chemicals, such as water-based paints,
for more toxic substances, such as oil paints.
Clean and dry damp areas or
places where bacteria or fungi can grow.
Isolate machines that release
toxic fumes, such as photocopier.
Make sure hazardous work is
done only on the weekends, and inform the union before it begins.
Ensure that people who work
with hazardous chemicals are protected with adequate ventilation
or protective equipment, such as respirators.
Provide information about all
chemicals in use, as required by the New York State Right to
Know Law and the Occupational Safety and Health Administration's
Hazard
Communication Standard.
Maintain temperature within
the comfort zone of 65 to 75 degrees Fahrenheit and humidity
within a relative humidity of 30 - 60%.
Ensure that all local exhaust
systems pull polluted vapors away from people's breathing area
and that local systems do not compete with the primary ventilation
system.
Bring in a ventilation engineer
to ensure that air movement is sufficient and to recommend remedies
for any problem areas. This investigation can determine if you
meet the American Society of Heating, Refrigerating and Air Conditioning
Engineers (ASHRAE) indoor air quality standards, which recommend
20 cubic feet per minute (cfm) of fresh air per person in offices.
A simple tool called a velometer is used to take these measurements.
Carry out any changes and improvements
recommended by the ventilation engineer.
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What Your Union
Can Do
Develop a health and safety committee
to work to correct indoor air, and other, problems.
Conduct a health survey
of the members, looking for problems typical of indoor air
pollution and check to see if symptoms are linked to the job.
Investigate
your building's ventilation system. Find out what type of ventilation system, if any,
is used. (To check the effectiveness of a ventilation system,
hold tissue paper near the vents to see if they're working -
there should be both a supply and exhaust vent in each room.
Also check for problems with local exhaust systems.)
Develop recommendations and priorities
for improving air quality.
Write contract language that
will protect your rights to clean air. Your union representative
can suggest sample language and you may also want to use the
ASHRAE standard as a guide.
Consider filing a complaint with
the New York State Department of Labor's Division
of Safety and Health or OSHA
if you have a well-documented problem and you are not making
any progress with management. You may also want to file a request
for a Health Hazard
Evaluation conducted by the National Institute for Occupational
Safety and Health. According to law, employers must provide
safe, healthful workplaces that are free of hazards, including
indoor air pollution. (always work with your union representative
when filing a complaint. But don't stop working! Complaints to
the Department of Labor, OSHA or DOSH are no substitute for consistent
union action.)
Find out about legislative activity
- and get involved. While there is no federal or New York State
regulation on indoor air pollution, legislation has been proposed
and several other states have enacted indoor air pollution laws.
For a list of other information
on the internet about indoor air quality, click
here.
For recent news articles about
indoor air quality, click
here.
(Adapted from: American Lung
Association factsheet; NYCOSH factsheet produced through a grant
from the NY State Dept. of Labor, Occupational Safety and Health
Training and Education Grant Program [COO5443]; Women's Occupational
Health Resource factsheet)
For a printer-friendly,
Portable Document Format version of this factsheet, click
here.
The “This page was last updated on” line just below reflects the date on which this page was transferred to this redesigned website. The information in this page (as opposed to the design) was last updated on October 22, 2003.
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