United States Indoor Environments Division (6607J) EPA-402-F-96-004
Environmental Protection Agency Office of Radiation and Indoor Air October 1996
Indoor Air Quality
Basics for Schools
This fact sheet provides important information on
indoor air quality (IAQ) in schools to parents and
others who do riot normally occupy school buildings.
Once you understand the basics mat influence indoor
air quality in a school, you will note that prevention
and problem solving mainly involve two major actions
— the management of pollutant sources, and the use of
ventilation to control pollutants. Following are the
key principles:
• Many IAQ problems can be prevented by school
staff and students
• When IAQ problems happen, they can often be
resolved using the skills of school staff
• The expense and effort required to prevent most
IAQ problems is much less than the expense and
effort required to solve problems after they
develop
Why IAQ is Important to Your School
Most people are aware that outdoor air pollution can
damage their health, but many do not know that
indoor air pollution can also cause harm.
Environmental-Protection Agency (EPA) studies of
human exposure to air pollutants indicate that indoor
levels of pollutants may be 2-5 times, and
occasionally more than lOO times, higher than
outdoor levels. These levels of indoor air pollutants
are of particular concern because it is estimated that
most people spend about 90% of their time indoors.
Comparative risk studies performed by EPA and its
Science Advisory Board have consistently ranked
indoor air pollution among the top four environmental
risks to the public.
Failure to prevent indoor air problems, or failure to
act promptly, can have consequences such as:
• increasing the chances for long-term and short:term
health problems for students and staff
• impacting the student learning environment,
comfort, and attendance
• reducing productivity of teachers and staff due to
discomfort, sickness, or absenteeism
• faster deterioration and reduced efficiency of the
school physical plant and equipment
• increasing the chance that schools will have to be
closed, or occupants temporarily moved
• straining relationships among school
administration and parents and staff
• creating negative publicity that could damage. a
school's or administration's image and
effectiveness
• creating potential liability problems
Indoor air problems can be subtle and do not always
produce easily recognized impacts on health, well-
being, or the physical plant. Children are especially
susceptible to air pollution. For this and the reasons
noted above, air quality in schools is of particular
concern. Proper maintenance of indoor air is more
than a "quality" issue, it includes safety and good
management of our investment in the students, staff,
and facilities.
•
'"Good indoor, air quali
favQtablv learning environment forjitndetti£ \ "* - _
product ivity __ ^
Understanding IAQ Problems
and Solutions
Over the past forty or fifty years, exposure to indoor
air pollutants has increased due to a variety of
factors, including the construction of more tightly
sealed buildings, reduced ventilation rates to save
energy, the use of synthetic building materials and
furnishings, and the use of chemically-formulated
personal care products, pesticides, and housekeeping
supplies. In addition, our activities and decisions,
such as delaying maintenance to "save" money, can
lead to problems from sources and ventilation. Four
basic factors affect IAQ: sources of indoor air pollut-
ants, the heating, ventilation, and air-conditioning
(HVAC) system, pollutant pathways, and occupants.
-------
Sources of Indoor Air Pollutants
Indoor air contaminants can begin within the building
or be drawn in from outdoors. If pollutant sources are
not controlled, IAQ problems can occur, even if the
HVAC system is working properly. Air pollutants
consist of numerous particles, fibers, mists, molds,
bacteria, and gases. It may be helpful to think of air
pollutant sources as fitting into one of the categories
Jn the table shown below.
In addition to the number of potential pollutants,
indoor air pollutant levels can vary within the
school building, or even a single classroom. Pollutants
can also vary with time, such as only once each week
when floor stripping is done, or continuously such as
when fungi is growing in the HVAC system.
HVAC System Design and Operation
The heating, ventilation, and air-conditioning
(HVAC) system includes all heating, cooling, and
ventilating equipment serving a school. A properly
designed and functioning HVAC system:
• controls temperature and humidity to provide
thermal comfort
Typical Sources of Indoor Air Pollutants
• distributes adequate amounts of outdoor air to meet
ventilation needs of school occupants
• isolates and removes odors and pollutants through
pressure control, filtration, and exhaust fans
Not all HVAC systems, are designed .to do all of these
things. Some buildings rely only on natural
ventilation. Others lack cooling, and many have
little or no humidity control.
Pollutant Pathways and Driving Forces
Airflow patterns in buildings are caused by mechan-
ical ventilation systems, human activity, and natural
effects such as wind. Air pressure differences created
by these forces move airborne pollutants from areas of
higher pressure to areas of lower pressure through
any available openings in building walls, ceilings,
floors, doors, windows, and HVAC system. An inflat-
ed balloon is an example of this driving force. As long
as the opening to the balloon is kept shut, no air will
flow, but when open, air will move from inside (area
of higher pressure) to the outside (area of lower
pressure). Even if the opening is small, air will move
until the pressures inside and outside are equal.
Outside Sources
Polluted Outdoor Air
• pollen, dust, fungal
spores
• industrial emissions
• vehicle emissions
Nearby Sources
• loading docks
• odors from dumpsters
• unsanitary debris or
building exhausts
near outdoor air
intakes
Underground Sources
• radon
* pesticides
• leakage from under-
ground storage tanks
Building Equipment
HVAC Equipment
• microbiological
growth in drip pans,
ductwork, coils, and
humidifiers
• improper venting of
combustion products
• dust or debris in
ductwork
Non-HVAC Equipment
• emissions from office
equipment (volatile
organic compounds,
ozone)
• emissions from shops,.
labs, cleaning
processes
Components/Furnishings
Components
• microbiological growth
on soiled or water-
damaged materials
• dry traps that allow the
passage of sewer gas
• materials containing
volatile organic com-
pounds, inorganic
compounds, or dam-
aged asbestos
• materials that produce
particles (dust)
Furnishings
• emissions from new
furnishings and floor-
ings
• microbiological
growth on or in soiled
or water-damaged
furnishings
Other Indoor Sources
• science laboratories
• vocational arts areas
• copy/print areas
• food preparation
areas
« smoking lounges
• cleaning materials
• emissions from trash
• pesticides
• odors and volatile
organic compounds
from paint, caulk,
adhesives
• occupants with com-
municable diseases
• dry-erase markers
and similar pens
• insects & other pests
• personal care products
-------
Building Occupants and Health
Building occupants in schools include the staff,
students, and other people who spend extended
periods of time in the school. The effects of IAQ
problems on occupants are often vague symptoms
rather than clearly defined illnesses. Symptoms
commonly attributed to IAQ problems include:
• headache, fatigue, and shortness of breath
• sinus congestion, cough, and sneezing
• eye, nose, throat, and skin irritation
• dizziness and nausea
All of these symptoms, however, may also be caused
by other factors, and are not necessarily due to air
quality problems. Environmental stressors such as
improper lighting, noise, vibration, overcrowding,
and psychosocial problems (such as job or home stress)
can produce symptoms that are similar to those
associated with poor air quality, but require different
solutions.
Because people are different, one individual may
react to a particular IAQ problem while surrounding
occupants have no noticeable ill effects. In other
cases, complaints may be widespread. In addition to
different degrees of reaction, an indoor air pollutant
or problem can trigger different types of reactions in
different people. Some groups that may be
particularly susceptible to effects of indoor air
contaminants include:
• allergic or asthmatic individuals, or people
with sensitivity to chemicals
• people with respiratory disease
• people whose immune systems are suppressed due
to radiation or chemotherapy, or disease
• contact lens wearers
Six Basic Control Strategies
There are six basic methods for lowering concentra-
tions of indoor air pollutants. Specific applications
of these methods are noted in the Indoor Air Quality
Tools for Schools Kit (see the back page for
information on the Kit).
Source Management includes source removal, source
substitution, and source encapsulation. Source
management is the most effective control method
when it can be practically applied. The best
prevention method is never to bring unnecessary
pollutants into the school building. Examples of
source removal include not allowing buses to idle near
outdoor air intakes, not placing garbage in rooms
where HVAC equipment is located, and banning
smoking within the school. Source substitution
includes actions such as selecting less toxic art
material or interior paint than the products which
are currently in use. Source encapsulation involves
placing a barrier around the source so that it releases
fewer pollutants into the indoor air.
Local Exhaust is very effective in removing sources of
pollutants before they can be dispersed into the
indoor air, exhausting the contaminated air outside.
Well known examples include restrooms, kitchens,
and science lab fume hoods. Other examples of
pollutants that originate at specific points and that
can be easily exhausted include science lab and
housekeeping storage rooms, printing and duplicating
rooms, and vocational/industrial areas such as
welding booths.
Ventilation uses cleaner (i.e., outdoor) air to dilute
the contaminated (i.e., indoor) air that people are
breathing. Generally, local building codes specify
the amount of outdoor air that must be continuously
supplied to an occupied area. For situations such as
painting, pesticide application, or chemical spills,
temporarily increasing the ventilation can be useful
in diluting the concentration of fumes in the air.
Exposure Control includes the principles of time of
use and location of use. An example of time of use
would be to strip and wax floors on Friday after
school is dismissed, so that the floor products have a
chance to release gases over the weekend, reducing
the level of odors or contaminants in the air when the
school is occupied. An example of location of use
involves moving the contaminating source as far as
possible from occupants, or relocating susceptible
occupants.
Air Cleaning primarily involves the filtration of
particles from the air as the air passes through the
ventilation equipment. Gaseous contaminants can
also be removed, but usually this type of system
should be engineered on a case-by-case basis.
Education of the school occupants is critical. If
school staff are provided information about the
sources and effects of contaminants under their
control, and about the proper operation of the
ventilation system, they will better understand their
indoor environment and can act to reduce their
personal exposure.
-------
How Do I Know if There is an IAQ Problem
Diagnosing symptoms that relate to IAQ can be
tricky. Acute (short-term) symptoms of IAQ problems
typically are similar to those from colds, allergies,
fatigue, or the flu. There are clues, however, that can
serve as indicators of potential indoor air problems:
• the symptoms are widespread within a class or
within the school, potentially indicating a
ventilation problem
• the symptoms disappear when the students or
staff leave the school building for the day
• the onset is sudden after some change at school,
such as painting or pesticide application
• persons with allergies, asthma, or chemical
sensitivities have reactions indoors but not
outdoors
• a doctor has diagnosed a student or staff member
as having an indoor air-related illness
However, a lack of symptoms does not mean that the
quality of the air within the school is acceptable.
Symptoms from long-term health effects (such as lung
cancer due to radon) often do not become evident for
many years. For this reason, schools should establish
a preventive indoor air program to minimize exposure
of students and staff to indoor air pollutants (see
information on the "Kit," next section).
What Should I Do if I Think a School has
an IAQ Problem
If your child, or someone else you know, is exper-
iencing symptoms that you believe may be related to
their school environment, contact a school official
immediately, such as the school IAQ Coordinator, or
the health and safety coordinator. Whether or not
the school has a known problem, encourage the school
to obtain and use the Indoor Air Quality Tools for
Schools Kit. This easy-to-use Kit shows schools how
to carry out a practical plan of action at little or no
cost, using in-house staff.
The Kit includes simple checklists for all school
employees, a flexible step-by-step guide for using the
checklists, an Indoor Air Quality Problem Solving
Wheel, a fact sheet on indoor air pollution sources
What You Can Do
1. Read this fact sheet
2. Ensure that your
school gets the
Indoor Air Quality
Tools for Schools Kit
3. Ensure that your
school uses the Kit
and solutions, sample
memos to help school
personnel respond to
inquiries, and sample
policies.
The Kit is co-sponsored
by the'National PTA,
National Education
Association, Council for
American Private Education, Association of School
Business Officials, American Federation of Teachers,
and the American Lung Association.
The Federal government, as well as most State and
local governments, do not have regulations or
enforcement capabilities regarding indoor air quality
in schools. For some schools, assistance may be
available from the local or State departments of
health or environment. The Federal or State
occupational safety and health office (OSHA) may
also provide some help.
How to Order the Kit
The Indoor Air Quality Tools for Schools Kit, item
number 055-000-00503-6, can be purchased for $22 from
the U.S. Government Printing Office. MasterCard
and Visa are accepted. For telephone orders, call
202-512-1800. Or send a check or money order to:
Superintendent of Documents
PO Box 371954, Pittsburgh, PA 15250.
While supplies last, school districts and schools may
receive a free copy of the IAQ Tools for Schools Kit
by having a school administrator mail or fax a
request on official school letterhead to:
EPA Kit
PO Box 37133
Washington, DC 20013-7133
Fax: 202-484-1510
Other information on IAQ is available by contacting
your Regional EPA office, or by calling 800-438-4318.
10-9-96
------- |